A potent jet streak overhead resulted in strong/gusty winds across the high plains on 5 April 2022. The wind combined with dry conditions, resulted in a broad area of elevated to critical fire weather conditions. Further, a shortwave trough rounding the base of a broader upper low to the north sent a cold front south through the high plains, resulting in dramatic wind shifts along it’s path. NWS Dodge City, KS summarized the situation well leveraging GOES water vapor imagery (Fig 1): “Water vapor imagery shows a strong upper level jet moving into the Pacific Northwest and northern Rockies overnight with an upper low starting to close off along the border of Montana and Canada. This low will move out across the Dakotas into Minnesota today into tonight. A cold front will move south across western Kansas today…”
Figure 1: 05 April 2022 GOES-East UL WV Imagery, RAP 500 mb height contours (white), and 500 mb wind speed contours (color) depicting upper jet streak.
A large wildfire developed in the Oklahoma Panhandle early in the day within gusty westerly winds, but abruptly spread south with the passage of a cold front. An AWIPS procedure captured all aspects of this situation, and is shown in Figure 2. Using the Geocolor as the base layer, we overlay the 10.3 um channel with 10% transparency and a white/cold to black/warm grayscale colormap centered on the brightness temperature range of the pre and post frontal clear sky, and 3.9 um shortwave IR brightness temperature >45 C to capture hot spots. The first part of the animation captures the wildfire hot spot and smoke plume as the cold front approaches. Once the cold front and associated wind shift push through the fire, the hot spot quickly begins to move south, along with the low-level portion of the smoke plume. The shallow nature of the cold airmass is apparent in the smoke plume behavior, with only the low-level portion nearest the fire falling within northerly flow, while further aloft, the plume continues to drift east within the westerly flow.
Figure 2: 5 April 2022 GOES-East 1-min GOES-East Geocolor, semi-transparent IRW, hot SWIR.
The location of the wildfire fell within three consecutive VIIRS passes around the time of the frontal passage, allowing for a detailed (spatially) view of the fire and wind shift. The VIIRS Natural Fire Color RGB with a similarly semi-transparent VIIRS LWIR channel overlay is shown in Fig 3.
Figure 3: 5 April 2022 VIIRS Natural Fire Color RGB, semi-transparent 10.3 um LWIR.
While surface obs provide the ideal source of quantitative information regarding wind shifts, satellite imagery (especially 1-min as in Fig 2) can be leveraged to analyze frontal movement and associated wind shift with more spatial and temporal detail. In cases of wind shifts at a wildfire, such real-time information is extremely important in the protection of life and property, both for the local public and for emergency personnel working the fire (see example from one year ago here).
For this event, NWS Amarillo, TX (AMA) leveraged GOES Imagery and products in order to illustrate the dramatic fire growth associated with the frontal passage on social media (see post below). NWS/AMA also utilized satellite imagery for their Decision Support Services (DSS) phone briefings supporting the Beaver County fire and other fires in the area. Specifically, the GOES 1-min satellite imagery allowed forecasters to track the front in detail and communicate to emergency personnel the precise timing of the impending change in wind direction at each fire. The Beaver County EM confirmed that they moved personnel based on the NWS briefings of the frontal passage timing, which they got directly from watching the 3.9 um satellite imagery. In particular, forecasters noted their use of the 1-min 3.9 um band (which captured the frontal position and hot spots well) with the Fire/Hot Spot derived product (Fire Temperature) as an overlay (See Figure 4 for grayscale version and wide view of area).
4/5 @ 5PM: Here's a quick look at the ongoing fire up in Beaver County, OK. The video starts just before the front reaches the fire and ends about 1.5 to 2 hrs after the frontal passage. The fire has grown significantly. Stay safe and do what you can to prevent fires. #phwxpic.twitter.com/bqDDkQZmkt
Thunderstorms and their associated severe winds have a long history of impacting aircraft. Many tragic incidents demonstrate how avoiding the turbulent updrafts and downdrafts within thunderstorms is paramount to protect the aircraft and ensure the safety of the passengers and crew. Convective activity can significantly alter flight paths for both commercial and general aviation. Airlines incur costs in the tens of millions of dollars each year in extra fuel, diversions, and labor costs to manage thunderstorm-related impacts and delays. This case study uses GOES-R series satellite imagery to examine severe weather and its relationship with the resultant flight paths of nearby aircraft.
In mid-May 2019, a strong upper-level trough was present over the western United States, advecting positive potential vorticity over the Central High Plains and the upper Great Plains (Fig. 1). Upper-level support for ascent was combined with low-level support in the form of a developing leeside surface cyclone advancing northeastward across northeast Colorado and into northwest Kansas and southwest Nebraska. A mesoscale dry line front developed along the downslope terrain of eastern Colorado and western Kansas, providing strong localized support for convective initiation coupled with thermodynamic atmospheric parameters supportive of further convective development. This eventually resulted in thunderstorms and severe weather in the form of tornadoes, large hail, and damaging winds.
Fig. 1: CONUS imagery from GOES-16 of the Channel-9 Water Vapor imagery from the Central United States. A dry line front is clearly visible as drier air (yellow shades) advancing eastward through eastern Colorado.
The National Centers for Environmental Prediction (NCEP) Central Operations stewards a meteorological observational archived database called the Meteorological Assimilation Data Ingest System, or MADIS. MADIS incorporates data from a wide variety of sources, including international, federal, state, and local agencies, universities, volunteer networks, and the private sector. Part of this private sector data included within MADIS is the location, time, heading, and altitude for registered aircraft within US airspace reporting via the Aircraft Communications Addressing and Reporting System (ACARS). Aircraft data from MADIS is encrypted such that flights specifics (i.e., tail number, aircraft operator, etc.) are not seen by the user, but the archived locations and headings of registered aircraft are available. While this dataset takes considerable care to develop into a GIS-friendly product, it can be a powerful tool to demonstrate the impacts weather has on aviation.
For this severe weather event, convective initiation was a core component of the forecast. Thunderstorms were expected to mature quickly as insipient updrafts were able to break through a relatively strong capping temperature inversion. The Geostationary Lightning Mapper (GLM) supplies valuable satellite confirmation of convective initiation by quickly highlighting the initial flashes and their spatial extent with gridded imagery. The GLM lightning observations pair well with GOES-16 ABI imagery, including the Day Cloud Phase Distinction RGB, which can highlight the development of ice and charge separation within clouds. Please note, the Day Microphysics RGB, which has notably different ingredients and recipe from the more familiar NWS AWIPS Day Cloud Phase Distinction RGB, but shares a similar purpose, is shown in this blog post. In this RGB and relevant to our discussion in this case, convective initiation can be diagnosed as cumulus clouds grow and transition from shades of tan/pale yellow to deeper red/orange.
From NWS Goodland at 1919 UTC: “GOES-16 Day-Cloud Phase Distinction imagery indicating a few failed attempts at thunderstorm initiation along dry line and with mesoscale data supporting ML inhibition between 50 in the south to 150 j/kg in the north. Will likely take another hour of insolation to further weaken capping, which will coincide with approaching pv anomaly from the west. Expect strong storms to fire between 2 and 3 pm MDT. Relatively high LCL’s and weak 0-1km shear support initial threats being very large hail greater than 2 inch and diameter. Tornado threat is somewhat low, but should increase as storms move east and north towards triple point near NE border and as LLJ increases around 6 PM.”
Overlaying the ACARS flight data with the GOES-16 Day Microphysics RGB during the early afternoon hours before initiation along the dry line near the Colorado/Kansas border shows a busy corridor of aviation traffic arriving at and departing from Denver International Airport (DEN) as well as many other busy regional airports in the area (Fig. 2). It is also apparent how planes are instructed to fly along arranged routes from point to point, and how those routes can be adjusted on the fly by weather. A considerable amount of traffic traveling across the domain appears to have taken off from and is destined for airports which are not displayed here. [The destinations and origins of the aircraft are not specified in this dataset available to the public.]
Fig. 2: Mesoscale Sector and CONUS imagery from GOES-16 of the Day Microphysics RGB from the Central High Plains in the time leading up to convective initiation. Overlaid is the Flash Extent Density gridded imagery from the GLM and the reported locations and headings from archived ACARS flights.
The failed attempts at convective initiation in the early afternoon as noted by NWS Goodland can be seen on the RGB imagery, and it finally gave way to thunderstorm activity around 2020 UTC. Just before the first lightning strikes are observed by the GLM, a distinct, robust turret confirming the presence of a building updraft can be seen in the RGB imagery just southwest of the GLD airport (Fig. 2). At the same time, more widespread red pixels, associated with an increasing amount of ice present at the top of the cloud, are shown in the RGB imagery just before lightning was first observed with this particular storm by the GLM.
After convection began in earnest along the dry line, it is clear that the rapidly developing weather conditions were having a significant impact on aviation by affecting the flight paths of hundreds of aircraft in this area. However, when looking at Channel-13 Longwave Infrared ABI imagery alone (Fig. 3), it is difficult to ascertain distinct trends in the flight paths of aircraft when compared to brightness temperatures at the top of the cloud. The gridded products from the GLM provide insights into the spatial extent of lightning with satellite-based lightning observations with 1-minute updates over much of the full disk of both GOES-East and GOES-West. The spatial extent of lightning can be investigated with the Flash Extent Density GLM gridded imagery through supercell development as in Figure 4.
Fig. 3: Mesoscale Sector and CONUS imagery of the Channel-13 Longwave IR ABI from GOES-16. Overlaid is the reported location and headings from archived ACARS flights.
The GLM provides unique observations of the spatial extent of lightning, and in this context demonstrates how aircraft are diverting around ongoing lightning flashes within thunderstorms as they are occurring. The convective cores of the thunderstorms can generally be identified by the more numerous flashes occurring within or near the updraft. Greater flash counts manifest as warmer colors in Flash Extent Density imagery, and vice versa. Due to the relatively low flash rates in this event, the standard color scale for Flash Extent Density may not always highlight convective cores.
Fig. 4: Mesoscale Sector and CONUS imagery from GOES-16 of the Day Microphysics RGB from the Central High Plains from before convective initiation through 00Z on 18 May 2019. Overlaid is the Flash Extent Density gridded imagery from the GLM and the reported locations and headings from archived ACARS flights.
Another GLM product which may provide additional value in identifying the location of rapidly evolving convective updrafts is Minimum Flash Area, which reports the area in square kilometers of the smallest lightning flash observed by the GLM within each pixel in the specified time window. In addition to being more numerous, flashes which are more associated with strengthening or mature updrafts are typically smaller in spatial extent. This occurs because of the large amount of charge separation taking place over a spatially small area within the vertically oriented updraft. Thus, Minimum Flash Area highlights these updrafts, with warmer colors indicating smaller minimum flash sizes, and vice versa. Minimum Flash Area alone can provide a significant amount of context for immediate impacts on not only aviation but also severe weather warnings and reports (Fig. 5).
Fig. 5: GOES-16 GLM Minimum Flash Area gridded imagery overlaid with NWS Severe Thunderstorm (yellow) and Tornado (red) warning polygons, CWSU SIGMET advisories (orange polygons), severe weather reports from the SPC archive (with similar symbol styling), and the reported locations and headings from archived ACARS flights. Note that there may be some spatial offset between the satellite-based GLM observations and ground-based observations approaching the edge of the field of view of the GLM; read more here.
Aircraft take a circuitous route on this day to avoid thunderstorm activity, if possible. Flash Extent Density alone may not necessarily give the full perspective on which lightning strikes pilots and air traffic control may be actively avoiding. Minimum Flash Area imagery provides additional context on which flashes are more likely associated with core convective updrafts and which are more likely associated with the anvil/stratiform regions by classifying flashes by the size of their spatial extent. In this imagery and in other cases, airplanes tend to more acutely avoid the more numerous, smaller flashes within the turbulent updrafts, and less so avoid the less frequent, larger, anvil/stratiform region flashes.
Incorporating the GLM gridded products of lightning observations into aviation forecasting operations can be a vital tool for meteorologists when spotting convective initiation and turbulent updrafts by classifying lightning flashes by their spatial extent. This additional information about convective activity can more precisely guide aviators through natural hazards such as thunderstorms, snow squalls, and other atmospheric phenomena.
One key advantage of the Nighttime Microphysics RGB is its ability to depict low-level cloud layers at night. These are marked by elevated red and green contributions within the RGB recipe, however a case from 6 April 2022 shows that not all low-level clouds look the same. Overnight a cold front was advancing southeastward through the central United States. Behind the cold front (Oklahoma, Kansas, Missouri, and Arkansas) we see that the stratus clouds are colored green-yellow, however, the stratus clouds ahead of the cold front (Texas, Louisiana, Mississippi, and Alabama) are light blue. The question is why?
While stratus clouds often have strong contributions from the red and green bands (indicating thick, water clouds), the relative bluecontribution from the Channel 13 Clean-IR Brightness Temperature (10.3 um) can highlight the relative temperature differences of stratus clouds. See the abbreviated RGB recipe for the Nighttime Microphysics RGB below.
To see this effect for yourself, you can compare the Nighttime Microphysics RGB to the Clean-IR Brightness Temperature imagery using the slider tool below. Note the position of the cold front (via the surface observations), where the colors of the stratus clouds change in the Nighttime Microphysics RGB, and the higher/lower Clean-IR Brightness Temperatures ahead/behind the cold front.
During the early morning hours of 14 March 2022, a plume of moisture from the Gulf of Mexico was advected northward prior to a severe weather setup later that day. Along with surface observations and RAP surface analysis data, imagery from the GOES-16 Nighttime Microphysics RGB provided conformation of this moisture advection with stratus clouds developing across eastern Texas and southern Oklahoma (green-yellow) from Figure 1. Strong contributions in the red and green bands signify thick clouds that mostly contain water, helping to determine that these are low level stratus clouds driven by the synoptic scale advection of low level moisture across the region.
Figure 1: The GOES-16 Nighttime Microphysics RGB from 08 Z to 11 Z over the Southern Plains. Note the increasing coverage of stratus clouds (green-yellow) across eastern Texas and eastern Oklahoma.
The NWS Storm Prediction Center issued a Slight Risk for northeast Texas and the Ark-La-Tex region, with all hazards (tornadoes, large hail, and damaging winds) possible (see slideshow below). Use of the Nighttime Microphysics RGB in this scenario may provide conformation of the moisture advection, along with its current spatial extent in regions where few surface observations exist. Monitoring the extent of these stratus clouds also provides a ‘first look’ at which areas will receive more or less solar heating during the morning, which may impact the initiation time, coverage, and maximum strength of convection later in the day.
A broad trough and embedded shortwaves digging east across the southern US brought severe weather, including tornadoes, to parts of the south and southeast US on 21-22 March 2022. The evolution of the trough across the country is shown well in 6.2 um GOES-East Water Vapor Imagery in Figure 1. GLM FED is also included in the animation as progressively more opaque yellow atop the green cold clouds.
Figure 1: 20-23 March 2022 GOES-East Water Vapor Imagery, GLM FED.
Adding RAP sfc and upper level analysis fields onto the water help one to better understand features in the imagery by associating them with familiar fields, such as 500 mb height and wind speed, and sfc pressure (Figure 2).
Partially overlapped GOES-East 1-min mesoscale sectors resulted in a corridor of 30-second imagery across central Texas. The difference between 30-second imagery and 1-min imagery may not sound like a lot, put processes that are occurring on such small timescales do appear notably smoother to the human eye in the side-by-side comparison. This is exemplified in an animation of visible imagery over a tornado-producing severe thunderstorm on the border of 30-sec and 1-min imagery (Fig 3).
Figure 3: 21 March 2022 GOES-East 30-sec VIS (left) and 1-min VIS (right) over north-central Texas.
Further south near San Antonio, the evolution of the cu field leading up to eventual convective initiation is captured in 30-second Day Cloud Phase Distinction imagery. The 2.5 hour animation (300 images) reveals a cumulus field becoming increasingly agitated with the growth of cumulus clouds into towering cu, eventual glaciation with the colors changing from blue/cyan to green, to convective initiation diagnosed by vertical growth and transition of colors from green to yellow/red (Fig 4). The growth of the eventual first severe-warned storm occurs under high cirrus (red), but can be followed in the very high temporal resolution imagery.
Figure 4: 21 March 2022 GOES-East 30-sec Day Cloud Phase Distinction RGB Imagery over central TX.
Post convective initiation, 30-second imagery of storm maturation captured the evolution of storm top features, such as overshooting tops and an above anvil cirrus plume, in much detail (Fig 5). The imagery is extremely fluid, and ensures forecasters are receiving updates about the storm faster than ever. The animation is 240 images, or 2 hours long.
Figure 5: 21 March 2022 GOES-East 30-sec VIS over central TX. Gif version
During the same period of 30-second imagery, adding a semitransparent 10.3 um overlay, resulting in the VIS/IR Sandwich, helps to capture the storm top features a little better by including the quantitative brightness temperature information (Fig 6).
Figure 6: 21 March 2022 GOES-East 30-sec VIS/IR Sandwich Imagery over central TX. . GIF version
After viewing the 30-sec animation a few times, take a peak at the 1-min animation of the same scene. It is fascinating how 1-min imagery appears relatively “choppy” (Fig 7)!
Figure 7: 21 March 2022 GOES-East 1-min VIS over central TX. . GIF version
The most impressive storm developing near San Antonio exhibited an exposed updraft in the GOES-East 30-second imagery. Rocking a 30-sec visible imagery animation of this storm over a 25 minute period reveals counterclockwise rotation of the updraft (Fig 8). Extending west of the updraft is the more horizontally oriented flanking line. Inflow feeder clouds are also analyzed southeast of the updraft, as well as an overshooting top and above anvil cirrus plume at the storm top. Given the presence of high clouds, and rapid evolution, some of these features can easily be missed in coarser temporal resolution imagery.
Figure 8: 21 March 2022 GOES-East 30-sec VIS over central TX, rocking animation.
As was shown in Figure 1+2, the convective threat shifted east to the southeast on the 22nd as the broad upper trough shifted east and another shortwave and associated strong jet streak spread across the region. Two strong thunderstorms passed through the New Orleans area just after sundown, and were captured in GOES-East 1-min ABI and GLM imagery. The northern storm produced an EF1 tornado, while the thunderstorm produced an EF3 tornado. The 1-min IR imagery revealed rapidly cooling cloud tops just prior to the initial tornado reports between 0024 UTC and 0029 UTC (Fig 9).
Figure 9: 22 March 2022 GOES-East 1-min IR over southeast LA, NWS Severe thunderstorm, Tornado, Marine Warnings.
GLM FED associated with the storms included rapid upticks in total lightning activity leading up to tornado development (Fig 10). The FED data highlights the location and movement of the most intense storm updrafts, as well as the presence of lightning flashes and resulting lightning danger well removed of the storm core.
Figure 10: 22 March 2022 GOES-East 1-min IR, GLM FED over southeast LA, NWS Severe thunderstorm, Tornado, Marine Warnings.
Finally, combining the GLM Flash Extent Density with Minimum Flash Area into a single RGB reveals where an abundance of small flashes (indicative of strengthening updraft) were occurring, as bright shades of yellow (Fig 11). Red represents low FED and small flashes, so a transition from Red to Orange to yellow in this RGB indicates increasing numbers of small flashes. Shades of blue represent long flashes, which are often present with the anvil regions of the thunderstorms, as well as with decaying updrafts.
Figure 11: 22 March 2022 GOES-East 1-min IR, GLM FED/MFA RGB over southeast LA, NWS Severe thunderstorm, Tornado, Marine Warnings.
A significant shortwave trough digging across the Four Corners brought strong winds to a large swath of the southern High Plains on 17 Mar 2022, resulting in widespread blowing dust and critical fire weather conditions. GOES-East Water Vapor Imagery combined with RAP Analysis fields allows one to connect features observed in the imagery with those present in SFC/UL charts (Fig 1). In this case, a surface low is analyzed deepening out ahead (east) of the main mid-level cyclonic circulation associated with the mid-level trough. A mid-level (70+ knot) jet streak rounds the base of the trough and is associated with a meridional temperature gradient in the water vapor imagery. The warming in the water vapor imagery here also represents a region of drying/descending air. Deep vertical mixing during the day across the dry/warm region helped to mix down the increasing mid-level winds, resulting in strong surface wind gusts.
As is typically shown, basic split window difference imagery captures lofted dust quite well, and is represented here as darkest shades of gray (Fig 2). The area of lofted dust is coincident with the downward momentum transport and drying observed in water vapor imagery, circling the mid-level circulation.
Figure 2: 17 March 2022 GOES-East Split Window Difference Imagery.
The SWD is combined with IR and SWIR imagery to yield a Dust-Fire RGB, which shows the blowing dust as bright green, wildfire hot spots as red, and clouds as varying shades of blue (Fig 3).
Figure 3: 17 March 2022 GOES-East Dust-Fire RGB Imagery.
DEBRA Dust imagery results from a more advanced algorithm that highlights suspected dust, based on the IR techniques, onto visible imagery as shades of yellow (Fig 4). DEBRA Dust is available on CIRA Slider.
Figure 4: 17 March 2022 GOES-East DEBRA Dust Imagery.
Two, GOES-East mesoscale sectors of 1-min imagery each were positioned over the region to capture the widespread wildfire threat. A 3-hr long 1-min animation of Geocolor imagery combined with a hot SWIR range provides a nice depiction of the blowing dust and wildfire development (Fig 5). The Geocolor imagery from GOES-East, especially later in the afternoon (increasing forward scattering), depicts aerosols quite well, including blowing dust as shades of brown/tan, and wildfire smoke as gray. By including only hot (40+C) shortwave IR pixels as an overlay, we are able to capture wildfire hot spots as well (yellow). Click the following 1-min and 30-sec animations for better resolution views. Geocolor is available on CIRA Slider, STAR Image Viewer, and coming soon to every AWIPS.
Figure 5: 17 March 2022 GOES-East 1-min Geocolor+SWIR Imagery.
Because the two GOES-East mesoscale sectors overlapped slightly, 30-second imagery was available (in the overlap region). This partially overlapped meso sector 30-sec imagery can be accessed in AWIPS with some simple configuration additions. Thirty-second Geocolor imagery of early upper-level cloud cover evolution is shown in in Fig 6, while a wildfire hot spot, smoke plume, and blowing dust are shown in Fig 7.
Figure 6: 17 March 2022 GOES-East 30-sec Geocolor Imagery.Figure 7: 17 March 2022 GOES-East 30-sec Geocolor+SWIR Imagery.
Strong southerly winds within a dry antecedent atmosphere a few days later on 20 March resulted in another day of critical fire weather conditions and blowing dust. A Geocolor + Fire Power derived product + SWD Dust Enhancement AWIPS display captures the evolution of the wildfire hot spots and smoke plumes across Texas, and broad plume of blowing dust across west Texas (Fig 8). By employing the Fire Power product in this type of display, as opposed to the SWIR imagery, one needs not worry about setting thresholds for hot spot detection.
An early March shortwave trough brought a wide range of active weather to much of the central United States on 04-05 March 2022, including snowfall, blowing dust, low clouds and fog, wildfires, and severe thunderstorms. GOES Satellite imagery was leveraged by forecasters in operations to detect and track the varying hazards, some of which are documented below.
Water vapor imagery is analyzed by forecasters to help gain an understanding of the recent and current observed synoptic scale setup in the atmosphere. How are these features influencing our weather now, and how might they influence our weather in the future? Analyzing water vapor imagery from the evening of the 4th through the morning of the 5th, key features to note include a broad toughing over the western US while a ridge builds to the east (Fig. 1). Within the broad trough, a shortwave lifts northeast across the Four Corners, and another closed circulation dips south across N California. A mid/ul jet max is analyzed in the imagery rounding the base of the Four Corners trough, denoted by the eastward spread of drying (warming BTs).
Figure 1: 04-05 Mar 2022 GOES-East UL WV Imagery, RAP 500 mb height contours.
NWS forecast discussions focus on details relevant to their local weather, and how features in WV imagery influence their forecast decision-making.
From PUB at 2226 UTC on the 4th: “Current water vapor imagery is indicating deep southwest flow aloft across the state as a strong jet core is rounding the base of an upper low spinning across the southern Great Basin. Clouds and isolated showers/virga associated with an embedded wave this morning across the plains have cleared with associated lee troughing on the plains leading to gusty south to southwest winds developing across the plains this afternoon, with a few areas hitting red flag criteria attm. Further west, satellite imagery and regional radars indicating cloud top cooling and scattered showers and isolated thunderstorms moving across eastern Utah and into western Colorado attm.”
And from OUN at 0915 UTC on the 5th: “… but we did go a little drier given upstream observations and significant drying noted on the lower layer water vapor imagery as ejecting mid-level jet spreads northeastward from southern New Mexico.”
And from Topeka at 1000 UTC on the 5th: “As of 3 AM, water vapor imagery notes a negatively-tilted upper trough axis over the Colorado Rockies and is continuing to eject northeastward across the central plains. An induced lee cyclone has continued to deepen in southeast Colorado and is beginning to move northeast across westcentral Kansas and soon towards southcentral Nebraska… The lee cyclone will continue to move northeast across northcentral Kansas and into southeast Nebraska throughout the day today bringing a variety of weather concerns….”
During the morning of the 5th, less snow had fallen across northeast CO and southeast WY than guidance had indicated leading up to the event. The culprit could be observed in satellite imagery, as CYS mentions by 1137 UTC: “Radar and satellite both show relatively little signal of any significant precipitation much further south of the WY/CO border. GOES-16 imagery in the water vapor channel shows much drier air pushing northward against the cloud shield associated with the strengthening surface low. Diffluent motion in the cloud cover can also be discerned from satellite imagery over our area. This trend, combined with recent hires guidance, has guided a slight northward shift in our targeted area of heaviest snow, resulting in reduced snow totals along I-80 from Cheyenne to Sidney, but increased totals further north, especially in the Wheatland/Chugwater area.” This activity is apparent by the end of Fig 1.
Playing the water vapor animation through Saturday evening, the eastward progression of the dry/descending air and associated southwesterly jet is observed across the AZ/NM/Mexico border and into the central/southern plains as the mid/upper low shifts ene across NE/IA .
Figure 2: 04-05 Mar 2022 GOES-East UL WV Imagery, RAP 500 mb height contours.
I could go one with additional water vapor imagery applications for this case, but there are other great applications to share! Along the southern periphery of the broad trough under the associated jet, gusty westerly to southwesterly winds mixed to the surface from southern CA to W Texas during the afternoon on the 4th and again on the 5th. This led to areas of blowing dust, reducing visibility, and resulting in the issuance of warnings and advisories
From ABQ on the 4th at 2120 UTC: “Blowing dust is evident on the latest Dust RGB loops (Fig 3)and lower vsbys have been reported at a few obs sites.” This area of blowing dust in northwest NM prompted the issuance of several Dust Storm Warnings.
Figure 3: 04 Mar 2022 GOES-East Dust RGB Imagery. Blowing dust appears shades of pinks to red.
Looking south in the EPZ forecast area: “Looking at split window GOES satellite imagery (Fig 4)… streamers of blowing dust are moving in from the Chihuahuan dust sources, so that small amount of precip isn’t doing much for dust inhibition.” A Dust Storm Warning was also issued for one of these streamers. The SWD is the key ingredient to satellite based dust detection RGBs and algorithms. Used alone, it is a great source for dust detection. Combining it with other data sources allows for the creation of more advanced products that can further isolate dust and provide information about additional features such as clouds, wildfires, etc.
Figure 4: 04 Mar 2022 GOES-East SWD Imagery
Well north during the overnight hours of the 4th – 5th, BIS leveraged satellite imagery and fog probability products to assess fog/freezing drizzle potential: “Currently, surface low pressure was situated over the central Plains states with a weak reflection of an inverted trough northward into western North Dakota. Weak surface convergence was occurring here with surface observations and satellite fog probability product (Fig 6) indicating stratus/fog over western and south central ND and this is likely where any significant freezing drizzle remains. Farther east, dewpoint depressions increase quite a bit as you get into eastern portions of central ND with MVFR rather than IFR ceilings. Think the freezing drizzle potential here is very low. Will likely take a last look before issuing the products to see where we can trim off portions of the current advisory.” Viewing the new (with RPM v22, in Local Menu Items) Nighttime Microphysics + L2 product Readout, one can sample the RGB to view the Fog Probability Product readout information in the context of the RGB image, all in a single display (Fig 6, left). Learn more about this here.
Figure 6: 0951 UTC 05 Mar 2022 GOES-East Nighttime Microphysics RGB with cursor readout including Fog Probability product readout (left), MVFR probability (top right), IFR probability (bottom right).
To the northeast, TOP was providing IDSS to partners by alerting them to new wildfire starts per GOES Imagery: “Several fire have already been detected via GOES satellite imagery (Fig 7) and have been reported by local officials this afternoon.” At least five hot spots can be confidently diagnosed in the Fig 7 animation within the TOP forecast area. A sixth and seventh may be present to the southeast under the cloud cover. Early alerts of new wildfire starts (or significant developments of already established wildfires) may help emergency crews locate the fire, and allow them to arrive at the scene, sooner than otherwise. Other such examples have been documented on this blog (see here and here).
Figure 7: 05 Mar 2022 GOES-East SWIR Imagery. Hotter BTs represented by darker gray to black.
Two mesoscale sectors of 1-min imagery each were requested by NWS to support forecast operations on the 5th. One meso sector was requested by NWS Tulsa for Critical Fire Weather over the Southern Plains, and the other by SPC for the midwest severe weather threat. These sectors overlapped considerably across E OK/KS/KE and W MO/IA. As a result, 30-second imagery was available over these areas. When the center point of two meso sectors is the same (30-second imagery is requested), the meso overlap imagery can be viewed as meso-1 in AWIPS. This is not the case for a partial overlap. A few simple AWIPS modifications allows one to view this 30-second partial meso overlap imagery (hopefully the subject of a future AWIPS update). The thunderstorm associated with the EF4 Winterset/Newton Tornado developed within the overlap area, and is shown in Figs 8 and 9. Severe storm indicators present in the imagery include inflow feeder clouds, persistent overshooting tops, and above anvil cirrus plumes. Rotation of the exposed updraft may also be apparent at times.
Figure 8: 05 Mar 2022 GOES-East 30-sec VIS Imagery Figure 9: 05 Mar 2022 GOES-East 30-sec VIS Imagery, storm relative.
GOES-T launched successfully from Cape Canaveral, FL at 2138 UTC 01 March 2022. Given quiet weather elsewhere, 30-second mesoscale sectors from both GOES-East and GOES-West were collected imagery over the launch location, capturing fascinating details about the rocket hot spot and plume.
Starting with the GOES-East view of the launch, visible imagery captured the condensation trail (Fig 1), while SWIR imagery revealed the hot spot (Fig 2).
Figure 1: 01 March 2022 GOES-East VIS.Figure 2: 01 March 2022 GOES-East SWIR.
Combining VIS/NIR and SWIR gives us the Natural Fire Color RGB, which shows the hot spot along with the condensation trail (Fig 3).
Figure 3: 01 March 2022 GOES-East Natural Fire Color RGB.
Zooming out, an even longer vapor trail is visible in the 6.2 um water vapor imagery, along with the hot spot signature (Fig 4).
Figure 4: 01 March 2022 GOES-East UL WV.
Finally, combining the VIS, SWIR, and water vapor imagery, we are able to capture all features, including the hot spot (yellow), condensation trail (dark blue), and vapor trail (lighter green/mustard compared to background; Fig 5). This “Plume RGB” is recently available in AWIPS per the TOWR-S RPM v22 update, in the Local Menu Items menu.
Figure 5: 01 March 2022 GOES-East Plume RGB.
Similar bands/RGBs from GOES-West capture the launch from a much greater Viewing Zenith angle, providing a different perspective (Fig 6-9).
Figure 6: 01 March 2022 GOES-West VIS.Figure 7: 01 March 2022 GOES-West Natural Fire Color RGB.Figure 8: 01 March 2022 GOES-West UL WV.Figure 9: 01 March 2022 GOES-West Plume RGB.
An intense upper trough digging into the southwest US resulted in widespread strong winds and regions of blowing dust during the day on 15 Feb 2022. Per NWS Las Vegas, NV: “This mornings water vapor imagery (Fig 1) depicts a compact closed low dropping southward through central California with a swift southwesterly flow extending out ahead of it. Winds have been picking up through the night but will continue to increase through the remainder of the morning hours aided by a strengthening pressure gradient and daytime mixing.”
Figure 1: 15 Feb 2022 GOES-East 6.2 um Water Vapor Imagery.
In association with the south-moving cold front and possibly convectively enhanced, a wall of dense blowing dust, or haboob, surged south through Death Valley in CA near the NV border. See photo here. Again from NWS VEF: “Visible satellite imagery also depicted a well developed wall of dust progressing southward across Death Valley, possibly enhanced by some shower activity enhancing post frontal surface winds. Given the satellite presentation and susceptibility to dust storms in Death Valley, issued a Dust Storm Warning through 245 pm for the Furnace Creek and Death Valley junction region.”
NWS VEF leverages GOES visible, Geocolor, and Dust RGB imagery in their decision making during such blowing dust events. In events such as this one, satellite imagery is the primary method for deciding to issue a Dust Storm Warning. Corresponding GOES-West Geocolor imagery and referenced Dust Storm Warning polygon is shown in Fig 2. The wall of dust is obvious in the imagery surging south along the CA/NV border. Also notable in the imagery is the lack of data between 1900 and 2010 UTC. This was a planned GOES-17 outage. Note, GOES Geocolor imagery will be available to all NWS offices in the coming months.
Figure 2: 15 Feb 2022 GOES-West Geocolor Imagery.
GOES-16 also provides useful imagery over the region, and captured the haboob well (Fig 3). The SWD (Fig 4a) signal was quite strong, resulting in the obvious signature in Dust RGB imagery as well (Fig 4b).
Figure 3: 15 Feb 2022 GOES-East Geocolor Imagery.Figure 4a: 15 Feb 2022 GOES-East SWD-IR combo.Figure 4b: 15 Feb 2022 GOES-East Dust RGB Imagery. Enlarge
VIIRS Day Land Cloud RGB imagery provided a 375 m resolution view of the haboob as well, including 3 images during a ~100 minute period (Fig 5).
Figure 5: 15 Feb 2022 VIIRS Day Land Cloud RGB.
Considerable blowing dust developed elsewhere across the southwest US within the increasing southwesterly winds, resulting in multiple Dust Storm Warnings and Blowing Dust Advisories. An SWD-IR-L2 product combo, newly available with the recent AWIPS TOWR-S update, captures the many areas of lofted dust (dark gray) well, while also providing cloud brightness temperature information (Fig 6). Note, it is recommended to adjust the SWD colortable range to ~ -2 to 8 when using the SWD with B-W colortable to detect blowing dust.
Figure 6: 15 Feb 2022 GOES-East SWD-IR Imagery.
One can access hidden L2 product information from this new menu item by sampling the scene, in this case revealing a confirmation of dust (Aerosol Dust product), as well as the considerably dry airmass (TPW) in NW NM (Fig 7). The Dust RGB + L2 Readout option includes similar information.
Figure 7: 15 Feb 2022 GOES-East SWD-IR Imagery with L2 product readout.
NWS El Paso, TX notes their use of satellite imagery in tracking the lofted dust during this event (Fig 8): “Winds are increasing, especially across the Bootheel where a wind advisory remains in effect this afternoon and evening. Satellite imagery also shows several dust plumes moving NE out of Mexico with the thickest dust noted in Luna County. Deming is reporting 2 to 4 mile vis, while the Border Patrol station at Columbus reported 100 feet. A blowing dust advisory is in effect to account for this plume as well as some other plumes over Hidalgo County.”
Figure 8: 15 Feb 2022 GOES-East Geocolor Imagery over S NM.
NWS Phoenix, AZ was also busy tracking areas of blowing dust in satellite imagery throughout the day (Fig 9): “So far today, wind gusts upwards of 45-55 mph have been recorded across portions of southeast California with slightly stronger gusts recorded in southwest Imperial County. As a result, areas of blowing dust have been generated. The most notable dust plumes showing up on visible satellite imagery this afternoon have been originating near Anza Borrego and spreading eastward across Imperial County. Additional dust plumes have been noted across eastern Riverside County near Blythe. Visibility in these areas have dropped down to around a mile or even lower at times. Thus, A Blowing Dust Advisory is in effect for much of southeast California through this evening.
Figure 9: 15 Feb 2022 GOES-East Geocolor Imagery over S CA/SW AZ.
Bill Line, NESDIS and CIRA, Stanley Czyzyk, NWS/VEF
Previously warm temperatures across the region had caused an aging the snowpack to crust over, limiting its “blowability”. However during the day/evening of the 10th, another quick-moving shortwave brought an additional round of fresh snowfall to Red River Valley region in E ND and W MN. As discussed in a great NWS/FGF forecast discussion on the 10th:
“This is a classic arctic front blizzard set up. The main issue is that the warm temperatures ahead of the cold front will make the current snowpack nearly unblowable. With that said, water vapor imagery indicates an upper level wave (currently way upstream) that should lead to an area of very light falling snow behind the cold front, and combined with the strong winds would lead to a 3-5 hour period of blizzard conditions. Most guidance does indicate very light QPF. Typically, in these CAA regimes we tend to develop additional convective snow showers, which would prolong the blizzard type impacts. However, the development and intensity of these convective snow showers is uncertain. If the snow showers persist, blizzard conditions would last into Friday afternoon.”
As discussed in the above forecast, plummeting temperatures and strong winds behind the front indeed resulted in widespread blowing snow by the early morning hours of the 11th, lasting into the afternoon and aided by the development of HCRs, especially across the Red River Valley. GOES-East imagery was utilized by NWS/FGF forecasters during this event to narrow down the spatial extent of the Blizzard Warning, as discussed here and below. Corresponding GOES-East Imagery is shown over the region in Fig 1, along with the warning decision on the NWS WWA map (Fig 2).
“Along the glacial lake valley floor horizontal convective rolls can be seen on satellite and from KMVX radar indicating blizzard conditions with widespread white outs causing many east to west road closures in MN and portions of I29. With the help of the satellite imagery did narrow the blizzard warning and removed the tier of counties from Roseau to Mahnomen along with western Walsh and Cavalier in ND.”
Figure 1: 11 Feb 2022 GOES-East experimental Blowing Snow RGB. Last image highlights corridor of most intense blowing snow.
Figure 2: 11 Feb 2022 NWS Watch/Warning/Advisory map before and after trimming of Blizzard warning based on satellite imagery.
Afternoon VIIRS passes provide an alternative, high resolution view of the blowing snow and related HCRs (Fig 3+4).
Figure 3: 1818 and 1911 UTC 11 Feb 2022 VIIRS experimental Blowing Snow RGB.Figure 4: 1911 UTC 11 Feb 2022 VIIRS experimental Blowing Snow RGB zoomed in look around Grand Forks.
A full day (2/11) GOES-East animation captures the longer term evolution of the blowing snow and HCRs across the Red River Valley (Fig 5).
Figure 5: 11 February 2022 GOES-East experimental Blowing Snow RGB.
Satellite Liaison Blog 
