Satellite Liaison Blog

GOES-R & JPSS: The Future of Weather Satellites

  • Home
  • About the Blog

RGB Applications: Anticipating Convective Initiation Using the Nighttime Microphysics RGB

Posted by Carl Jones on 01/27/2021
Posted in: Uncategorized. Leave a comment

While there are many, many, many examples of RGB’s excelling at diagnosing the early stages of convection during the daytime, there seems to be a lack of examples showcasing similar RGB use during the nighttime. This is likely due to the absence of solar reflectance, particularly in the near-infrared. Reflectance within this wavelength spectrum aids in monitoring the stages of early convective growth through easy detection of cloud top glaciation. Such reflectance gives RGB’s like the Day Cloud Phase Distinction its superiority in monitoring the convective lifecycle. But is there an RGB that can perform a similar application without solar reflectance, i.e. at night? This post will attempt to shed light [get it?] on how the Nighttime Microphysics RGB can be utilized in anticipating convective initiation.

On the night of August 18, 2020, forecasters at the National Weather Service in Grand Forks monitored the potential for overnight thunderstorm development, but were unsure if forcing would be sufficient enough to overcome strong capping over the area. There was anticipation of a low level jet to develop somewhere over eastern North Dakota into northwest Minnesota serving as a potential spark to ignite convection through the capping inversion. While questions remained on where exactly this would happen, focus was given to the mesoanalyst role to monitor for this potential.

Nighttime Microphysics RGB. Higher res

At around 12:30 am CDT, the Nighttime Microphysics RGB easily picked up on low level stratus developing northeastward over the northern Red River Valley in far northwest Minnesota. This stratus stood out from other nearby clouds with its telltale pale cyan color compared to higher level dark blue and red cousins to the east and south.

4 panel display of the Nighttime Microphysics RGB and it’s components in black to white color scale. Top left: Nighttime Microphysics RGB. Top right: red gun, the Split Window Difference (SWD; 10.3-12.3 um). Bottom left: green gun, the Night Fog difference product (10.3 – 3.9 um). Bottom right: blue gun, the clean longwave infrared band (LIR; 10.3 um). Higher res

The pale cyan color is a result of increased values within the green gun, the Night Fog difference product (10.3 – 3.9 um), as well as a slight dimming in the blue gun, the longwave infrared band (LIR; 10.3 um), while no information was added from the red gun, the Split Window Difference (SWD; 10.3-12.3 um). These were all signs of low level stratus, mainly through the increased values within the Night Fog product indicative of clouds made of up water droplets. While it drew the attention of the forecasters, questions still remained: Does this low stratus represent the seeds to convection? Or is this simply a benign cloud feature?

Nighttime Microphysics RGB. Higher res

Over the next hour, characteristics of this cloud feature changed. The low stratus changed from its uniform pale cyan color and ameba-like structure, growing dark red specks that slowly veered and expanded east-southeast.

4 panel display of the Nighttime Microphysics RGB and it’s components in black to white color scale. Top left: Nighttime Microphysics RGB. Top right: red gun, the Split Window Difference (SWD; 10.3-12.3 um). Bottom left: green gun, the Night Fog difference product (10.3 – 3.9 um). Bottom right: blue gun, the longwave infrared band (LIR; 10.3 um). Higher res

The change in color is a result of increased values in the red gun (SWD), sharply decreasing values in the green gun (Night Fog product), and further decreasing values in the blue gun (LIR). This indicated parts of the stratus cloud were starting to glaciate as suggested by the sharp decrease in values from the Night Fog product, continued cooling in the LIR, and increasing difference between the “clean” and “dirty” LIR channels (SWD).

The awareness and knowledge of the subtle change in cloud characteristics as illustrated by the Nighttime Microphysics RGB was crucial in realizing the stratus cloud was continuing to grow one or more updrafts that were beginning to glaciate. This is analogous to the Day Cloud Phase Distinction RGB revealing glaciation of water comprised cumulus, a threshold designating convective initiation.

So we proved that the Nighttime Microphysics RGB can be used to assess convective initiation, but we already have other satellite tools to do this for us, particularly the 10.3 um LIR channel. This single LIR band has a long standing legacy as a useful tool in monitoring convective activity at night. But can this application of the Nighttime Microphysics RGB provide additional lead time towards convective initiation compared to monitoring cloud top temperatures on the 10.3 um LIR channel?

Side by side comparison of the Nighttime Microphysics RGB (left) and LIR (right) with annotations denoting important visual triggers. Higher res

The animation above is a time matched side by side comparison of the Nighttime Microphysics RGB and LIR band. In this case, the easily definable signal of stratus becoming glaciated within the RGB gave around 30 minutes to 1 hour of additional lead time in raising awareness toward potential convective initiation compared to typical LIR if using -24 C as a threshold (standard color curve for LIR in AWIPS turns blue at -24 C). This additional lead time allowed forecasters to feel better prepared in messaging and internal warning operations (better preparation =  less surprises and more confidence in warning/no-warning designation).

While the Nighttime Microphysics RGB can provide crucial information of pre-CI development, it lacks valuable cloud top information after CI, an area where LIR still reigns supreme. So why not have both?

Nighttime Microphysics RGB – LIR “sandwich.” Higher res

The animation above takes the best of both products by overlaying an adjusted LIR color table on top of the Nighttime Microphysics RGB. Simply make values lower than -24 C transparent within the LIR color table and keep it above RGB in the hierarchy of display within AWIPS. The LIR’s bright colors of ongoing convection probably stands out the most displaying details like a sprawling anvil, overshooting top, and warm trench indicative of an above anvil cirrus plume. But the RGB’s input in this same image can help focus attention west and north of ongoing convection. Notice the tight packs of small , discrete but glaciating cells as shown by a reddening color? This should raise awareness towards the potential of additional convection soon to initiate.

Nighttime Microphysics RGB – LIR “sandwich.” Higher res

This Nighttime Microphysics RGB – LIR “sandwich” yields information that is helpful in both the pre-CI and post-CI environment. The remainder of the loop showed that many cells matured into robust convection. And while not all of these glaciating cells went on to become mature storms (notice the orphan anvils?), it still signaled the potential of additional development outside of ongoing convection. This knowledge directly led to refined messaging of severe threats for targeted locations, bridging the gap between outlook and warning phases.

For those wondering what hazards this event brought: hail. Numerous reports of large hail up to the size of golf balls fell during the early morning hours of August 19, 2020, within the central Red River Valley into northwest Minnesota. More environmental information can be found via SPC’s Event Archive.

Carl Jones
Meteorologist
NWS Grand Forks

Widespread Dense Blowing Dust Plume – 15 Jan 2021

Posted by Bill Line on 01/15/2021
Posted in: Uncategorized. 2 Comments

Strong northerly winds on the backside of a broad central US low pressure system resulted in widespread dense blowing dust across the southern high plains on 15 Jan 2021. Wind gusts of 45-65 knots initiated blowing dust across eastern Colorado during the mid-late morning, which expanded south-southeast into southwest Kansas and the OK/TX panhandles by late morning into the early afternoon. The blowing dust resulted in widespread and prolonged visibility reductions to less than 2 miles, with temporary reductions to near-zero captured on video. These reduced visibilities prompted the issuance of multiple NWS Dust Storm and Blowing Dust warnings, as well as road closures.

Some images from within the dust plume:

#kswx chiseling. Doesn't seem to be helping any. Please stop blowing! pic.twitter.com/ZIA7FF4RL6

— A.J. Crotinger (@ajcrotinger) January 15, 2021

Hwy 40, 287 and I-70 are all closed. Do not travel if you are near these areas. #trafficalert #weatheralert pic.twitter.com/zV5bVBtdgu

— CSP La Junta&Lamar (@CSP_LaJunta) January 15, 2021

A GOES-East 1-min mesoscale sector was available over the region of blowing dust, thanks to a request the previous evening by NWS Norman for Fire Weather. The initiation of blowing dust in the morning across southeast Colorado is observed and tracked efficiently by GOES-East 1-min VIS-SWD combo, a procedure which can be created in AWIPS (Fig 1). The combo uses a semi-transparent SWD overlay with a range centered around that of the dust signal, allowing areas of potential dust to “pop”. The animation depicts the issuance of Dust Storm Warnings in relation to the dust evolution.

Figure 1: 15 Jan 2021 GOES-East 1-min VIS-SWD combo, NWS Dust Storm Warning polygons. Higher res

According to a NWS Pueblo forecaster, the GOES imagery aided in determining where and where not significant blowing dust was occurring, and was used in combination with surface obs and webcams to issue the warning. See text below for one of the warnings issued by NWS Pueblo (Fig 2).

Panning out and observing the daytime evolution using GOES-East Geocolor, we see the location of the blowing dust in relation to the larger cyclone centered over Missouri/Illinois (Fig 3). The dust, in this case, is easy to diagnose in Geocolor, especially later in the day as forward scattering increases for GOES-East. Note, GOES-West provided slightly better detection of the dust in the reflectance bands and products during the morning (more forward scattering), but was only available at 10-min resolution, vs 5-min and 1-min from GOES-East.

Figure 3: 15 Jan 2021 GOES-East 5-min Geocolor. Higher res

The DEBRA-Dust product, available on the CIRA Slider, can similarly be used in combination with Geocolor imagery to highlight areas of blowing dust. With this event, the algorithm performed very well in capturing the blowing dust with no apparent false alarm, from both GOES-East (Fig 4a) and GOES-West (Fig 4b).

Figure 4a: 15 Jan 2021 GOES-East 10-min Geocolor and DEBRA-Dust combo. Higher res
Figure 4b: 15 Jan 2021 GOES-West 10-min Geocolor and DEBRA-Dust combo. Higher res

Given the strong dust signal, the Dust RGB also captured the dust signal quite well as red (Fig 5).

Figure 5: 15 Jan 2021 GOES-East 5-min Dust RGB. Higher res

Finally, blowing dust was easily detectable in the Dust-Fire RGB (relatively bright green), along with periodic wildfire hot spots (red pixels) within and near the dust (Fig 6). This RGB is a useful situational awareness tool for tracking both the evolution of blowing dust and new wildfire starts, phenomena which occur under similar environmental conditions.

Figure 6: 15 Jan 2021 GOES-East 5-min Dust-Fire RGB. Higher res

The NWS Aviation Weather Center issued multiple IFR SIGMETS due to the blowing dust, utilizing satellite imagery and surface obs (Fig 7). An AWC forecaster noted their increasing use of the Dust RGB in operations, and that it was utilized today to assist in product issuance.

Figure 7: AWC SIGMET during the afternoon of 15 Jan 2021.

VIIRS imagery provided a high resolution view of of the dust plume during the early afternoon. The Day Land Cloud RGB, created using the 1.6 um, 0.86 um, and 0.64 um I band channels for the RGB components, respectively, provides us with a 375 m RGB effective at highlighting lofted dust and distinguishing it from other features (Fig 8a and 8b). Blowing dust appears as relatively bright brown to tan, while liquid cloud tops are white/gray, ice cloud tops are cyan, and snow cover an even brighter cyan.

Figure 9a: 15 Jan 2021 NOAA-20 VIIRS Day Land Cloud RGB. Higher res
Figure 9a: 15 Jan 2021 NOAA-20 VIIRS Day Land Cloud RGB, zoomed in over southeast Colorado. Higher res

Even higher resolution imagery, 10 m true color, from Sentinel-2 was available over the blowing dust during the late morning when the event was well underway (Fig 9a and 9b). The zoomed in view captures areas of both transparent and opaque dust advancing across HWY 50 between Lamar and Holly in southeast Colorado.

Figure 9a: 15 Jan 2021 Sentinel-2 10 m True Color Imagery. Higher res
Figure 9b: 15 Jan 2021 Sentinel-2 10 m True Color Imager, zoomed in on lofted dust over southeast Colorado. Higher res

NWS offices experiencing the blowing dust were active on social media sharing GOES imagery of the event as part of their Decision Support Services.

A dust storm warning remains in effect until 115 pm MST (Jan 15, 2021) across the southeast plains of CO. Gusty north winds in excess of 60 mph continues to create poor visibilities in blowing dust emanating across the plains, as the CIRA DEBRA sat product (yellow) shows. #cowx pic.twitter.com/cABbpoI4Ci

— NWS Pueblo (@NWSPueblo) January 15, 2021

Main dust plume moving south now approaching I-40 in Carson and Gray counties. Visibilities will reduce to less than 4 miles at leading edge of plume w/further deteriorating conditions possible if dust plumes fills in more to the south w/dangerous driving conditions #phwx #TXwx pic.twitter.com/JmuwvuwL0S

— NWS Amarillo (@NWSAmarillo) January 15, 2021

Blowing dust is once again a concern across far southwest and west central Kansas as wind gusts picked back up during the mid-morning hours. Expect wind gusts 55 to 70 mph through early afternoon. Blowing dust will reduce visibility, locally, to less than a mile. #kswx pic.twitter.com/FimlTAuCNW

— NWS Dodge City (@NWSDodgeCity) January 15, 2021

To close, the full daytime evolution of the blowing dust viewed in the GOES-East 5-min Geocolor/SWD image combo, with Dust Storm Warning polygons overlaid (Fig 10).

Figure 10: 15 Jan 2021 5-min GOES-East Geocolor/SWD image combo, with NWS Dust Storm Warning polygons. Higher res

The blowing dust would continue to travel southeast through the night, reaching the Gulf of Mexico by the next morning. GOES-East IR-based multispectral products were effective in continuing to track the lofted dust through the evening. Shown is a modified version of the Dust RGB, with lofted dust appearing as a dark blue relative to surrounding areas (Fig 11). The CIRA geocolor product is appended to the start and end of the loop to capture the daytime reflectance view of the dust on either end.

Figure 11: 15-16 Jan 2021 GOES-East modified Dust RGB, Geocolor. Lofted dust appears as relatively dark blue. Higher res

Bill Line, NESDIS and CIRA, Steve Hodanish (NWS PUB), Declan Cannon (NWS AWC)

Southern High Plains Early Day Blowing Dust – 14 Jan 2021

Posted by Bill Line on 01/14/2021
Posted in: Uncategorized. Leave a comment

A shortwave trough digging southeast across the eastern Rockies and into the high plains sent a cold front south across the region during the overnight hours early on 14 Jan. Evolution of the shortwave and associated cold front can be analyzed in GOES Water vapor imagery from the 13th through the 14th (Fig 1). An overlay of RAP 250 mb wind speed shows the development of a 150+ knot (red contour) jet in relation to the water vapor features. The jet becomes increasingly amplified as it digs south on the backside of the broader trough and as the western US ridge builds. Fast moving high clouds are observed in the location of the jet core, along with a temperature gradient (cold to warm poleward) across the jet. Finally, plentiful gravity waves are apparent, many in association with the high terrain, throughout the animation, representing areas of potential aircraft turbulence.

Figure 1: 13-14 Jan 2021 GOES-East 6.2 um water vapor imagery. Higher res

Winds behind the front increased during the morning of the 14th, resulting in areas of blowing dust. Viewing GOES-East visible and geocolor imagery alone, however, the lofted dust is difficult to discern (Fig 2 and 3).

Figure 2: 14 Jan 2021 morning GOES-East 0.64 um VIS. Higher res
Figure 3: 14 Jan 2021 morning GOES-East Geocolor. Higher res

Bringing in IR based products, split window difference in Fig 4 and Dust-Fire RGB in Fig 5, the lofted dust becomes more apparent across southeast CO and southwest Kansas into the OK/TX panhandles and eastern NM. Note, for the SWD product, the VIS-Square-Root color table was applied with a range of -1 to 12. This allows the lofted dust signature on the low end of the range to pop (dark gray to black), while ensuring high clouds on the upper end of the scale do not become washed out (light gray to white).

Figure 4: 14 Jan 2021 morning GOES-East Split Window Difference. Shades of dark gray to black represent probable dust detection. Higher res
Figure 5: 14 Jan 2021 morning GOES-East Dust-Fire RGB. Shades of relatively bright green represent dust detection, and pixels of rich red represent wildfire hot spots (none apparent in this example). Higher res

The GOES-East DEBRA-Dust product, shown here as a semi-transparent overlay on Geocolor, also captures portions, but not all, of the blowing dust in the area (Fig 6).

Figure 6: 14 Jan 2021 morning GOES-East Geocolor+DEBRA-Dust. Shades of yellow represent dust detection. Higher res

Finally, the (10-min) GOES-East Aerosol Detection – Dust derived product, available during the daytime, did a decent job at capturing much of the dust during this period, primarily with medium to low confidence (Fig 6a).

Figure 6a: 14 Jan 2021 morning GOES-East VIS+ Aerosol Detection – Dust. Shades of blue represent dust detection, with high confidence as dark blue, medium confidence as medium blue, low confidence as light blue. Product becomes available for the day during the middle of this time period. Higher res

Turning our attention to GOES-West imagery, the lofted dust is significantly more apparent in the reflectance imagery/products; VIS in Fig 7 and Geocolor in Fig 8. The improved detection during the early daytime period by GOES-West vs GOES-East here is due to increased forward scattering given the position of the sensor (component west of location) relative to the sun (component east of location). Of note, the GOES-West CONUS sector does not extend east to this location. GOES-West full disk imagery (shown here) captures the event at 10-min resolution, but full resolution full disk imagery is not available to forecasters in NWS AWIPS. Therefore, forecasters would need to view the GOES-West products via other means (for example, CIRA Slider) in order to analyze the best high resolution view of the lofted dust during the morning. After midday, forecasters should transition to viewing GOES-East reflectance imagery for the ideal view of the lofted dust.

Figure 7: 14 Jan 2021 morning GOES-West VIS. Higher res
Figure 8: 14 Jan 2021 morning GOES-West Geocolor. Higher res

As pointed out by Tim Schmit (STAR/ASPB), the lofted dust was detectable in the 1.37 um “cirrus” band. Recall, this band is sensitive to absorption by moisture in the atmosphere, so to detect a near-surface/surface feature requires a dry atmosphere. Analyzing the imagery, the early day blowing dust discussed above was not apparent (Fig 9). However, a pocket of blowing dust becomes obvious by late morning traveling south across the middle of the domain. Comparing with surface observations, this area of blowing dust apparent in the 1.37 um imagery matches well with a minimum in surface dew point temperature (down to -2F!). The early day blowing dust occurred with dew points around 20F, confirming enough moisture was present in the atmosphere here to limit detection into the low-levels in the 1.37 um band.

Figure 9: 14 Jan 2021 GOES-East 1.37 um imagery, surface obs. Higher res

The southward progression of the dry air pocket is also diagnosed in GOES-East TPW imagery (Fig 10).

Figure 10: 14 Jan 2021 GOES-East 1.37 um imagery, TPW derived product, surface obs. Higher res

Bill Line, NESDIS and CIRA

Use of GOES Imagery During Oklahoma Fog Event

Posted by Bill Line on 01/07/2021
Posted in: Uncategorized. Leave a comment

GOES-East Day-Snow-Fog RGB imagery played an important role in operational decision-making at NWS Norman, OK (OUN) when forecasting fog and low stratus progression on 03 Jan 2021. Making this situation particularly difficult was the presence of snow cover beneath the thin low cloud/fog deck, as cloud features could not be easily discerned in visible satellite imagery alone. From OUN, “Since the area of fog/stratus was so thin, you could see the snowpack through the deck, making it even more difficult to discern on visible satellite. The RGB allowed the liquid cloud to “pop out” so we could see the development and dissipation trends.”

The forecaster on shift mentioned that the GOES-East RGB imagery influenced operational decision-making related to TAFs as well as the temperature forecast. Specifically, “Use of the Day Snow-Fog RGB was critical in my forecast for the KOKC TAF, along with hourly temperatures west of OKC. While we did have a TEMPO group of IFR conditions at KOKC for a couple of hours due to uncertainty and potential impact, the dense fog and stratus dissipated on the western and northern edge of the OKC runway complex. The high res models forecasted this area to persist through the afternoon across the OKC metro to the KOUN terminal area, but with the aid of the RGB trends, we were confident that it would not make it past the western parts of OKC.”

First, GOES-East 0.64 um imagery reveals, to an extent, low clouds evolving atop snow cover (Fig 1). Given the similar appearance between the low cloud cover and snow cover and semi-transparency of the cloud cover, the precise location and edges of the cloud cover is difficult to discern throughout the evolution.

Figure 1: 03 Jan 2020 GOES-East 0.64 um Visible satellite imagery. Higher res

Now viewing the Day-Snow Fog RGB, the low clouds pop as shades of light blue against the background of red (snow cover) and green (bare ground), allowing for it’s precise location to be more easily tracked in space and time (Fig 2).

Figure 2: 03 Jan 2020 GOES-East Day-Snow-Fog RGB satellite imagery. Higher res

Similarly, Day Cloud Phase Distinction RGB imagery can be utilized to discern low clouds (light blue) over snow cover (green) and bare ground (darker blue) with more clarity than VIS alone (Fig 3).

Figure 3: 03 Jan 2020 GOES-East Day Cloud Phase Distinction RGB satellite imagery. Higher res

Bill Line (NESDIS and CIRA), Kevin Brown (NWS/OUN), Randy Bowers (NWS/OUN)

12/23/2020 Blowing Dust and Blowing Snow

Posted by Bill Line on 12/23/2020
Posted in: Uncategorized. Leave a comment

An active synoptic pattern brought a wide variety of weather to portions of the central US during the day on 23 Dec 2020. From GOES-East water vapor imagery, one can diagnose a series of guilty shortwave troughs: one lifting northeast across the midwest, and the other on its backside digging southeast into the southern high plains (Fig 1).

Figure 1: 23 Dec 2020 GOES-East 6.2 um water vapor imagery. Higher res

The western shortwave trough sent a cold front south down the central/southern high plains during the morning, with gusty northerly winds developing in its wake. Given the dry antecedent conditions, widespread blowing dust developed, first across southeast Colorado, and spreading south into western Kansas and the TX/OK Panhandles.

GOES-East 1-min imagery was available over the region, capturing the blowing dust evolution through the day. During the morning, the lofted dust was clearly evident in 1-min animations of both the Geocolor and DEBRA-Dust products (Fig 2 and 3).

Figure 2: 23 Dec 2020 GOES-East 1-min Geocolor imagery. Higher res
Figure 3: 23 Dec 2020 GOES-East 1-min DEBRA-Dust product. Probable blowing dust is yellow. Higher res

A 2-min VIS feature-following zoom animation provides a unique perspective of dust plume relative evolution, including periodic cumulus cloud development atop the blowing dust (Fig 4).

Figure 4: 23 Dec 2020 GOES-East 1-min 0.64 um VIS, feature following. Higher res

Combining the Geocolor and DEBRA-Dust products for the duration of the daytime allows for the lofted dust to be highlighted within a more natural looking animation (Fig 5).

Figure 5: 23 Dec 2020 GOES-East Geocolor and DEBRA-Dust combo. Probable blowing dust is yellow. Higher res

In the absence of DEBRA-Dust in AWIPS, a similar product can be made by combining geocolor (or single-band VIS) with the SWD as an overlay and applying a varying transparency color table around the values for lofted dust (Fig 5b).

Figure 5b: 23 Dec 2020 GOES-East Geocolor and SWD combo. Probable blowing dust is yellow. Higher res

Finally, the Dust-Fire RGB captured the dust (relatively bright green) well, along with a few wildfire hot spots (red) in its path (Fig 6). Clouds (and very cold land) appear as various shades of blue.

Figure 6: 23 Dec 2020 GOES-East 5-min Dust-Fire RGB. Higher res

NWS Amarillo issued a great tweet highlighting the blowing dust in GOES-East Geocolor imagery:

Looking at a few areas of blowing dust in SW Kansas and the Oklahoma Panhandle. Some of this dust may continue to move south, but should stay aloft. #txwx #okwx #phwx pic.twitter.com/cRdZ8UOLjt

— NWS Amarillo (@NWSAmarillo) December 23, 2020

The blowing dust was captured in slightly higher detail in SNPP and NOAA-20 VIIRS geocolor imagery:

Figure A: 23 Dec 2020 SNPP and NOAA-20 VIIRS daytime Geocolor Imagery. Higher res imagery for times: 1937 UTC, 2028 UTC, 2119 UTC. Animation

To the northeast, on the backside of the eastern shortwave, gusty north winds forced areas of blowing snow. The blowing snow can be diagnosed in an RGB similar to the Day-Snow Fog RGB, but replacing the 0.86 um band with the higher resolution 0.64 um band for the red component, and making other minor adjustments. This RGB is introduced for regions of blowing snow in South Dakota (Fig 7) and ND/MN/Canada (Fig 8). Kudos to Carl Jones (NWS Grand Forks, ND) for pointing out these areas of blowing snow.

Figure 7: 23 Dec 2020 GOES-East 5-min Line Blowing Snow RGB. Similar to Day Snow Fog RGB, but with 0.64 um band as red component, and minor adjustments to ingredient ranges. Higher res
Figure 8: 23 Dec 2020 GOES-East 5-min Line Blowing Snow RGB. Similar to Day Snow Fog RGB, but with 0.64 um band as red component, and minor adjustments to ingredient ranges. Higher res

Bill Line, NESDIS and CIRA

Argentina Thunderstorms and Blowing Dust

Posted by Bill Line on 12/21/2020
Posted in: Uncategorized. Leave a comment

Widespread strong to severe thunderstorms developed across Argentina during the day on 18 December 2020. To capture the phenomena, a GOES-East meso-sector (-1) was positioned over the region, per a international request via the NESDIS Satellite Analysis Branch, which read, “Possible explosive cyclogenesis over central Argentina may bring heavy rains with possible severe thunderstorm and high surface winds”. GOES-East Full Disk water vapor imagery captured the evolution of a compact shortwave trough moving onshore in western South America and helping to spark widespread thunderstorm development (Fig 1).

Figure 1: 18 Dec 2020 GOES-East 20-min 6.2 um water vapor imagery. Higher res

A long duration (5-min-updating) IR-Window animation of the full mesoscale sector captures the evolution of the thunderstorms from the early day into the early nighttime (Fig 2). Not only are widespread thunderstorms detected, but an outflow boundary/cold front is analyzed racing north in the wake of the thunderstorms, adjacent to the high terrain, over the northwest portion of the sector (diagnosed as a sharp transition to relatively light gray, or cool, brightness temperatures).

Figure 2: 18 Dec 2020 GOES-East 5-min 10.3 um IR-Window imagery, within mesoscale sector 1. Higher res

First focusing on convective initiation for some of the most impressive, in appearance, thunderstorms, the Day Cloud Phase Distinction RGB, (at 1-min resolution) captured the trend from growing cu field (cyan clouds), to glaciation (cyan => green), to failed updraft attempts and orphan anvils (red/yellow) (Fig 2).

Figure 3: 18 Dec 2020 GOES-East 1-min Day Cloud Phase Distinction RGB ending just prior to CI. Higher res

Playing the full animation, successful convective initiation is observed shortly thereafter (Fig 3). Note, the RGB shown was modified from the default recipe, which quickly reaches the max threshold for the reflectance components during the summer. In this example, the green (0.64 um) component max was raised to 105%, while the blue (1.61 um) component max was raised to 65%. After making the adjustment, cloud top texture becomes apparent.

Figure 4: 18 Dec 2020 GOES-East 1-min Day Cloud Phase Distinction RGB through CI. Higher res

Following initiation, thunderstorms quickly matured and developed impressive storm top signatures, including rapidly expanding anvil, abundant texture, overshooting tops, and long-lived above anvil cirrus plumes, per 1-min VIS (Fig 4). In this example, a color table focusing on higher reflectance was utilized in order to best capture the storm top detail.

Figure 5: 18 Dec 2020 GOES-East 1-min VIS. Higher res

Over the same region and time period, a 1-min VIS-IR sandwich overlay provides more insight about the storm top features by adding brightness temperature information (Fig 5).

Figure 5: 18 Dec 2020 GOES-East 1-min VIS-IR Sandwich. Higher res

Now turning attention to activity near the outflow/cold front progression and lofted dust was apparent along and behind the boundary per 0.64 um VIS (Fig 6) and daytime Geocolor imagery (Fig 7). The DEBRA Dust product highlighted regions of most likely dust (Fig 8). The blowing dust along and behind the boundary apparent in the imagery acts as a fluid tracer of the dense air as it flows within the valley and interacts with higher terrain. Video of the blowing dust was captured from the region (see here and here).

Figure 6: 18 Dec 2020 GOES-East 2-min VIS. Higher res
Figure 7: 18 Dec 2020 GOES-East 2-min Geocolor. Higher res
Figure 8: 18 Dec 2020 GOES-East 2-min DEBRA-Dust imagery. Higher res

A Dust-Fire RGB not only shows the blowing dust (bright green), but also indicates wildfire hot spots (isolated pixels of bright red) in the scene (Fig 9). A large hot spot is detected in the southeast portion of the scene early in the period, while two smaller hot spots are found in the left center portion of the scene ahead of the cold front and blowing dust. Deep convection appears as blue, drier boundary layer as medium green, and a relatively moist boundary layer as medium-dark red.

Figure 9: 18 Dec 2020 GOES-East 2-min Dust-Fire RGB. Higher res

Finally, a longer VIS-IR transition animation captures the full evolution of the boundary and related blowing dust into the evening (Fig 10).

Figure 10: 18 Dec 2020 GOES-East 5-min VIS-IR sandwich, transitioning to IR after dark. Higher res

Bill Line, NESDIS and CIRA

Mid-Dec Northeast Snow

Posted by Bill Line on 12/17/2020
Posted in: Uncategorized. Leave a comment

A mid-December winter storm brought significant snowfall to the northeast US, including totals over 40″ (Fig 1)!

Figure 1: Snowfall analysis, 48-hr, ending 12Z 18 Dec 2020. Higher res. Link

GOES-East Water Vapor imagery from Sunday evening through Thursday morning captured the evolution of the shortwave trough, a key ingredient to the major winter storm, across the nation (Fig 2). An overlay of RAP analysis fields helps one to correlate the synoptic scale features apparent in the water vapor imagery with those in the upper level analysis. For example, the sharp temperature gradient on the southern periphery of the wave (cold on south side, warm on north side) represents the location of upper level jet winds. Additionally, the shortwave is easily identified given the cyclonic circulation apparent in animations, but also via the couplet of warm/dry descending air and cool/moist ascending air

Figure 2: 14-17 Dec 2020 GOES-East 6.2 um water vapor imagery. RAP analysis 500 mb height, 250 mb wind speed. Higher res

A IR-VIS/IR Sandwich transition procedure from GOES-East shows the evolution of the system along the east cost during the evening of the 16th into the morning of the 17th, with the surface low circulation becoming exposed during the daytime (Fig 3). The overlay of RAP analysis MSLP adds quantitative information about surface pressure trends and .

Figure 3: 16-17 Dec 2020 GOES-East IR/VIS-IR Sandwich Transition. RAP analysis MSLP. Higher Res

GLM imagery captured a few instances of lightning within areas of ongoing snow (thundersnow) during the overnight hours, including in W PA and SE PA early in the evening/animation, and then in NH by early morning and late in the loop. Abundant lightning was detected with thunderstorms off the coast along the front (Fig 4).

Figure 4: 16-17 Dec 2020 GOES-East IR, GLM 5-min FED. Higher res

During the day of the 17th, numerous interesting features could be diagnosed in the GOES-East Day Cloud Phase Distinction RGB imagery (Fig 5). Surface features in clear sky areas include melting snow in Maryland, snow cover extent, and snow cover over forested areas vs that over non-forested areas. As for cloud features, low clouds and fog (liquid clouds), including over snow, can be differentiated from high/glaciated clouds and potential areas of snowfall. The precise location of the surface low can be tracked, along with nearby and abundant gravity waves which can imply turbulence. Further, individual/narrow snow bands are diagnosed across E NY, CT, RI, and MA.

Figure 5: 17 Dec 2020 GOES-East Day Cloud Phase Distinction RGB. Higher res

A comparison for one time period between the DCPD RGB and MRMS composite reflectivity demonstrates the ability of the RGB to capture individual snow bands, which can be especially valuable as a compliment and in the absence of radar (Fig 6).

Figure 6: 1806 UTC 17 Dec 2020 GOES-East Day Cloud Phase Distinction RGB (left), MRMS Composite Reflectivity (right).

GOES-East 1-min mesoscale sectors were centered over the storm system during it’s evolution. One-minute visible imagery provided a detailed (spatially and temporally) view of the surface low circulation and adjacent cloud top gravity waves as it moved offshore (Fig 7).

Figure 7: 17 Dec 2020 GOES-East 1-min VIS. Higher res

Bill Line, NESDIS and CIRA

Mid-Dec 2020 NM/TX Blowing Dust Events

Posted by Bill Line on 12/17/2020
Posted in: Uncategorized. Leave a comment

A series of shortwave troughs brought strong winds and a pair of widespread blowing dust events to E NM and W TX on Dec 13 and Dec 15, 2020. The first event saw the lofted dust begin in E NM, and expanding east into W TX during the day in response to a compact and quick moving shortwave trough digging across the region per 6.2 um water vapor imagery (Fig 1). Imagery for the Dec 13 case comes from the CIRA Slider, while Dec 15 imagery comes from AWIPS and CIRA Slider.

Figure 1: 13 Dec 2020 GOES-East 6.2 um Water Vapor imagery. Higher res

The blowing dust was captured well in GOES Geocolor imagery, and as has been discussed in previous blog posts, diagnosis in the western US is better in GOES-West imagery during the early day, and GOES-East imagery during the late day (Fig 2-3).

Figure 2: 13 Dec 2020 GOES-West Geocolor imagery. Higher res
Figure 3: 13 Dec 2020 GOES-East Geocolor imagery. Higher res

A product not discussed much on this blog, but is available on the CIRA Slider, and upon request, in NWS offices AWIPS, is the DEBRA Dust product from CIRA (Fig 4). The product is effective in drawing attention to regions of potential blowing dust, prompting further interrogation.

Figure 4: 13 Dec 2020 GOES-East DEBRA-Dust Product. Probably dust is highlighted yellow. Higher res

The next blowing dust event occurred, primarily across W TX, after another shortwave and associated jet streak tracked across the area, captured again in WV imagery and also analyzed in RAP 500 mb height field and 250 mb wind field (Fig 5). Dry descending air is observed and an intensifying 120+ knot jet max analyzed across W TX during the time of strong surface winds and blowing dust.

Figure 5: 15 Dec 2020 GOES-East 6.2 um Water Vapor imagery, RAP 500 mb height (white contour), RAP 250 mb Wind Speed (color contour, knots, see scale). Higher res

The following GOES-East imagery has been discussed in numerous dust posts on this blog, and includes Geocolor (Fig 6), DEBRA Dust (Fig 7), SWD-IR Combo (Fig 8), and Dust-Fire RGB (Fig 9). Each of these displays has proven effective in reliable blowing dust detection. While Geocolor provides high resolution daytime detection option and DEBRA-Dust a high resolution day/night option (but with some false alarm), SWD-IR combo and Dust-Fire RGB (which incorporates the SWD), provide day/night dust detection (at slightly lower spatial resolution), along with cloud classification. The Dust-Fire RGB has the added benefit of incorporating wildfire hot spot detection, which often develop during such high wind events. This particular SWD-IR procedure includes the SWD as the gray scale bottom layer, Clear Sky Mask as the middle layer, and cold IR BTs as the color top layer, in order to isolate the blowing dust feature (darkest gray) from clouds, while also including cloud temperature information. All methods require the forecaster to do some degree of analysis and interpretation in order to make a determination on whether the feature is dust.

Figure 6: 15 Dec 2020 GOES-East Geocolor imagery. Higher res
Figure 7: 15 Dec 2020 GOES-East DEBRA Dust product imagery. Higher res
Figure 8: 15 Dec 2020 GOES-East SWD-IR imagery. Higher res
Figure 9: 15 Dec 2020 GOES-East Dust-Fire RGB imagery. Higher res

Exemplifying the multiple dust detection methods available to and used by operational forecasters, NWS offices across the region shared various imagery on social media during the events:

12/13: This satellite image from late Sunday afternoon shows an area of blowing dust moving out of the Trans-Pecos into the Rio Grande plains. The dust shows up as a brown haze extending from Sanderson to Langtry to Del Rio. As of 5 PM, the visibility in Del Rio was 4 miles. pic.twitter.com/FACW3bswZd

— NWS Austin/San Antonio (@NWSSanAntonio) December 13, 2020

Satellite imagery from the last couple of hours highlights several interesting features. 1) The upper low that passed through last night with breezy winds is now spinning over OK/KS. 2) Blowing dust has been kicked up in Midland. 3) Fresh snow on the Rockies. #nmwx #txwx pic.twitter.com/eS0nukYzph

— NWS El Paso (@NWSElPaso) December 15, 2020

Blowing dust is affect parts of the area today. The thickest dust is the dark gray/black feature moving southeast within the white line near Sterling City, San Angelo. Folks from Eldorado to Menard to Brady can expect to see some of this dust in the next hour or two. #txwx #sjtwx pic.twitter.com/L1JD5mtV4I

— NWS San Angelo (@NWSSanAngelo) December 15, 2020

Bill Line, NESDIS and CIRA

Overnight Fire Growth in Southern California

Posted by Bill Line on 12/03/2020
Posted in: Uncategorized. Leave a comment

Low relative humidities and strong wind gusts combined with very dry fuels resulted in the rapid development and growth of wildfires in southern California overnight on 12/2 – 12/3 2020. In fact, widespread wind gusts greater than 60 mph were reported, with a peak gust of 95 mph measured at Big Black Mountain. GOES-West 3.9 um imagery captured the wildfire development and evolution through the evening (Fig 1). The display also includes surface observations, which captured very nearby wind gusts to 46 knots. RAP RH analysis indicated widespread humidities below 15%, with values dipping as low as 5% near the wildfires.

Figure 1: 03 Dec 2020 GOES-West SWIR (hotter BTs are darker gray), surface obs, RAP sfc RH. Large fires are labeled in yellow. Higher res

VIIRS Day Night Band Near Constant Contrast Imagery, available in AWIPS, also captured the glow associated with the southern California Wildfires as they developed (Fig 2). Raising the “Max” value in the colormap range for NCC considerably (in this case to 30), allows the bright glow of the wildfires to stand out against the less bright city lights. During this evening, there were two passes of SNPP and one pass of NOAA-20 over this location, allowing for three images within a ~ 1 hour and 40 minute timespan. The VIIRS imagery is compared with a GOES-West SWIR image, exemplifying the significant amount of detail added from 750 m VIIRS DNB over 2 km (at nadir) ABI SWIR. The glow from the wildfires appears as very light gray to white, while city lights are a medium gray, in this example.

Figure 2: 03 Dec 2020 SNPP and NOAA-20 VIIRS DNB NCC (brighter light is whiter), GOES-West SWIR (hotter BTs are darker gray). Large fires are labeled in yellow. Higher res

Bill Line, NESDIS and CIRA

S Plains Blowing Dust – 11/14/2020

Posted by Bill Line on 11/22/2020
Posted in: Uncategorized. Leave a comment

A shortwave trough ejecting out of the Great Basin east into the central US plains sent a cold front south through the southern high plains during the afternoon/evening of 11 Nov 2020. Gusty winds developing ahead of and behind the front resulted in widespread blowing dust across the region. Widespread wind gusts in excess of 45 mph were reported, along with visibility reductions generally to around four miles, and in some cases, to near zero. The video below depicts the blowing dust during the afternoon in far east-central Colorado.

https://t.co/jQD6ISHOSD

— DW8525 (@CWCOWX) November 14, 2020

GOES-West water vapor imagery from the previous evening through the day on the 14th reveals the influencing trough as it tracked through the region (Fig 1).

Figure 1: 14 Nov 2020 GOES-West 6.2 um Water Vapor Imagery. Higher Res

Blowing dust already developed during the late morning and early afternoon across northeast Colorado. Lofted dust was captured well in an animation of 500 m visible imagery with a cold 10.3 um IR BT overlay in order to mask out clouds (Fig 2). The 500 m nadir resolution is adequate to pinpoint the source points of the many individual dust plumes, similar to smoke emanating from a wildfire hot spot.

Figure 2: 14 Nov 2020 GOES-East 0.64 um VIS and 10.3 um IR over northeast CO. Higher Res

The lofted dust was also captured during the day in the Day Land Cloud RGB which incorporates the 500 m VIS channel in addition to 0.86 um Veggie band and 1.6 um snow/ice band, allowing it to capture surface/near-surface features well and differentiate ice and water clouds (Fig 3).

Figure 3: 14 Nov 2020 GOES-East Day Land Cloud RGB over northeast CO. Higher Res

GOES-East Geocolor imagery provided perhaps the best depiction of the blowing dust during the daytime (Fig 3b). Further, 1-min imagery was available over the region during the event, allowing for a more detailed characterization to the dust evolution versus the 5-min conus imagery.

Figure 3b: 14 Nov 2020 GOES-East Geocolor over northeast CO. Higher Res

Similar animations capture afternoon blowing dust developing across southern Colorado, including dust collecting along the south-bound cold front as it tracked into the PHs (Fig 4-5).

Figure 4: 14 Nov 2020 GOES-East 0.64 um VIS and 10.3 um IR over southeast CO. Higher Res
Figure 5: 14 Nov 2020 GOES-East Day Land Cloud RGB over southeast CO. Higher Res
Figure 5b: 14 Nov 2020 GOES-East 1-min Geocolor over southeast CO. Higher Res

Dust was similarly lofted across E NM and W TX in dry conditions with strong westerly winds (Fig 6-7).

Figure 6: 14 Nov 2020 GOES-East 0.64 um VIS and 10.3 um IR over western TX. Higher Res
Figure 7: 14 Nov 2020 GOES-East Day Land Cloud RGB over western TX. Higher Res
Figure 7b: 14 Nov 2020 GOES-East 1-min Geocolor over W Texas. Higher Res

A GOES-East Geocolor animation captures the full daytime evolution of blowing dust across the southern High Plains.

Figure 7c: 14 Nov 2020 GOES-East Geocolor over the southern US high plains. Higher Res

While GOES-East visible imagery provided better detection of blowing dust during the afternoon/evening due to increasing forward scattering, GOES-West contributed a better depiction during the morning. Two areas of very active morning blowing dust are shown from the GOES-West perspective: southern Colorado just south of la Junta, and far southwest TX (Fig 8-9).

Figure 8: 14 Nov 2020 GOES-West 0.64 um VIS and 10.3 um IR over southeast CO. Higher Res
Figure 9: 14 Nov 2020 GOES-West 0.64 um VIS and 10.3 um IR over southwest TX. Higher Res

The blowing dust continued after dark (after 2311 UTC) across much of the same region, particularly along and behind the the cold front pushing south out of KS into the PHs. IR only animations also captured the blowing dust evolution. The advantage of the IR-only imagery products is that dust can continue to be diagnosed after dark, in addition to during the day.

The evolution of blowing dust during the day into the night is shown first in the SWD, using a simple linear grayscale color table, with IR Window cold BTs overlaid (Fig 10). This simple display reveals areas of likely blowing dust into the night (dark gray to black), along with cloud top temperature trend information.

Figure 10: 14-15 Nov 2020 GOES-East 10.3 – 12.3 um Split Window Difference over southern Plains. Higher Res

The default AWIPS Dust RGB, which incorporates the SWD along with the Split Cloud Top Phase and IR Window channel, captures the dust (pink) evolution into the night along with cloud top phase information (Fig 11).

Figure 11: 14-15 Nov 2020 GOES-East Default Dust RGB over southern Plains. Higher Res

Tweaks to that RGB, similar to those outlined in this blog post, help to make the lofted dust more easily diagnosable (dark cyan; Fig 12).

Figure 12: 14-15 Nov 2020 GOES-East Modified Dust RGB over southern Plains. Higher Res

Finally, another RGB discussed here allows for dust (bright green) tracking in addition to wildfire hotspot detection (Fig 13). In this case, there did not appear to be any active fires in the region during the time period.

Figure 13: 14-15 Nov 2020 GOES-East Dust-Fire RGB over southern Plains. Higher Res

750 m VIIRS True Color imagery captured the early evolution of the blowing dust from 1930 UTC (SNPP) to 2020 UTC (NOAA-20) across E CO (Fig 14) and W TX (Fig 15).

Figure 14: 14 Nov 2020 VIIRS True Color Imagery over E CO. From NASA Worldview Higher res
Figure 15: 14 Nov 2020 VIIRS True Color Imagery over E NM and W TX. From NASA Worldview Higher res

Finally, an even higher resolution view (10 m) of the blowing dust is captured by the Sentinal-2 mission. These data are only available over a given point every few days, and are not as quickly available to forecasters as the NOAA satellite data, but provide a very high resolution, confirming view after the fact in some cases. The images shared in Figures 16 and 17 show the very early stages of lofted dust (1753 UTC) across southern Wyoming (east of Cheyenne) and southeast Colorado (south of La Junta). The source points of the lofted dust are clearly evident in this imagery.

Figure 16: 14 Nov 2020 Sentinal-2 True Color Imagery over southern WY. From Sentinel Hub EO Browser. Higher res
Figure 17: 14 Nov 2020 Sentinal-2 True Color Imagery over southern CO. From Sentinel Hub EO Browser. Higher res

The following tweets from NWS Amarillo presents photo of the impending blowing dust in the Texas Panhandle, along with a satellite view (GOES Dust RGB) representing the extent of blowing dust and its forecast evolution.

4:33 PM CST, 11/14: A wall of #BlowingDust is moving through the northern #Texas Panhandle. This picture was shared with us from the Perryton Feeders along US Highway 70 south of #Perryton, #Texas. Expect sudden reductions of visibility (as low as 3 miles). #phwx #txwx pic.twitter.com/v3pcltSXtt

— NWS Amarillo (@NWSAmarillo) November 14, 2020

5:30 PM 11/14: #dust is moving through the northern Panhandles and is expected to continue spreading southward over the next couple hours through the blue highlighted area. Visibility could drop to around 3 miles so take it easy out there. #phwx pic.twitter.com/XqWXATK453

— NWS Amarillo (@NWSAmarillo) November 14, 2020

Bill Line, NESDIS and CIRA

Curtis Seaman and Dakota Smith (CIRA)

Posts navigation

← Older Entries
  • Follow Blog via Email

    Enter your email address to follow this blog and receive notifications of new posts by email.

    Join 2,179 other subscribers

  • RSS Satellite Liaison Blog

    • RGB Applications: Anticipating Convective Initiation Using the Nighttime Microphysics RGB
    • Widespread Dense Blowing Dust Plume – 15 Jan 2021
    • Southern High Plains Early Day Blowing Dust – 14 Jan 2021
    • Use of GOES Imagery During Oklahoma Fog Event
    • 12/23/2020 Blowing Dust and Blowing Snow
    • Argentina Thunderstorms and Blowing Dust
    • Mid-Dec Northeast Snow
    • Mid-Dec 2020 NM/TX Blowing Dust Events
    • Overnight Fire Growth in Southern California
    • S Plains Blowing Dust – 11/14/2020
  • Recent Posts

    • RGB Applications: Anticipating Convective Initiation Using the Nighttime Microphysics RGB
    • Widespread Dense Blowing Dust Plume – 15 Jan 2021
    • Southern High Plains Early Day Blowing Dust – 14 Jan 2021
    • Use of GOES Imagery During Oklahoma Fog Event
    • 12/23/2020 Blowing Dust and Blowing Snow
  • January 2021
    S M T W T F S
     12
    3456789
    10111213141516
    17181920212223
    24252627282930
    31  
    « Dec    
  • Keyword Search

  • Archives

    • January 2021 (4)
    • December 2020 (5)
    • November 2020 (1)
    • October 2020 (5)
    • September 2020 (1)
    • August 2020 (4)
    • June 2020 (4)
    • May 2020 (4)
    • April 2020 (8)
    • March 2020 (9)
    • February 2020 (6)
    • January 2020 (4)
    • December 2019 (3)
    • November 2019 (1)
    • October 2019 (5)
    • September 2019 (2)
    • August 2019 (5)
    • July 2019 (2)
    • June 2019 (1)
    • May 2019 (5)
    • April 2019 (7)
    • March 2019 (4)
    • February 2019 (4)
    • January 2019 (3)
    • December 2018 (2)
    • November 2018 (7)
    • October 2018 (3)
    • September 2018 (3)
    • August 2018 (1)
    • July 2018 (8)
    • June 2018 (5)
    • May 2018 (4)
    • April 2018 (5)
    • March 2018 (7)
    • February 2018 (5)
    • January 2018 (4)
    • December 2017 (4)
    • November 2017 (7)
    • October 2017 (9)
    • September 2017 (6)
    • August 2017 (12)
    • July 2017 (5)
    • June 2017 (9)
    • May 2017 (8)
    • April 2017 (17)
    • March 2017 (20)
    • October 2016 (1)
    • August 2016 (1)
    • July 2016 (1)
    • May 2016 (1)
    • March 2016 (2)
    • February 2016 (1)
    • October 2015 (1)
    • August 2015 (1)
    • July 2015 (1)
    • April 2015 (3)
    • March 2015 (3)
    • February 2015 (1)
    • December 2014 (1)
    • October 2014 (1)
    • September 2014 (3)
    • August 2014 (4)
    • July 2014 (1)
    • June 2014 (4)
    • May 2014 (9)
    • April 2014 (5)
    • March 2014 (3)
    • February 2014 (1)
    • January 2014 (1)
    • December 2013 (1)
    • November 2013 (1)
    • October 2013 (1)
    • June 2013 (2)
    • May 2013 (3)
    • April 2013 (1)
    • March 2013 (1)
    • February 2013 (2)
    • January 2013 (1)
    • December 2012 (1)
    • November 2012 (4)
    • October 2012 (10)
    • September 2012 (2)
    • August 2012 (1)
  • Categories

    • ABI
    • AirMass RGB
    • AIRS
    • Arctic
    • Aviation
    • AWC
    • Cloud Heights
    • Convection
    • CTC
    • Day-Night Band
    • Derived Stability Indices
    • Dust
    • Fires
    • Flash Flooding
    • G16-CH02_0.64_VIS-Red
    • G16-CH03_0.86_NIR-Veggie
    • G16-CH04_1.37_NIR-Cirrus
    • G16-CH05_1.6_NIR-SnowIce
    • G16-CH07_3.9_SWIR
    • G16-CH08_6.2_WV-Upper-Level
    • G16-CH09_6.9_WV-Mid-Level
    • G16-CH10_7.3_WV-Low-Level
    • G16-CH11_8.4_IR-SO2
    • G16-CH13_10.3_IR-Clean
    • G16-CH14_11.2_IR-Legacy
    • Heavy Rain
    • Himawari
    • Hurricane-Force Storms
    • Hurricanes
    • HWT
    • Ice
    • JPSS
    • Lightning
    • Microwave
    • MODIS
    • MTSAT-2
    • NearCast
    • News
    • NHC
    • OMPS
    • OPC
    • Overshooting Top Detection
    • ProbSevere
    • QPE
    • R2O/O2R
    • Rapid Intensification
    • RGB
    • Satellite Analysis Branch
    • Smoke
    • SPC
    • Split Window Difference
    • SRSOR
    • Super Rapid Scan
    • TAFB
    • Tornado
    • TPW
    • Tropical
    • Tropics
    • Uncategorized
    • VIIRS
    • Volcano
    • Water Vapor
    • Winter Weather
    • WPC
Powered by WordPress.com.
Satellite Liaison Blog
Proudly powered by WordPress Theme: Parament.