Microwave

It must be October. . .Super Typhoon Vongfong!

Posted by Michael Folmer on 10/07/2014
Posted in: Day-Night Band, Lightning, Microwave, Tropical, VIIRS. 2 Comments

There are certain things you can count on seeing in October.  Great post-season baseball!  Pumpkin flavored everything!  Halloween!  Super Typhoons?!  To celebrate the successful launch of Himawari-8 from Japan last night, I thought it would be appropriate to post on this latest super typhoon.

Super Typhoon Vongfong has intensified impressively in the last 24 hours after passing through the Marianas Islands yesterday as a Category 2 typhoon with winds ~105 mph.  As of 1500 UTC, the Joint Typhoon Warning Center initialized Vongfong as a 135 kt (155 mph) super typhoon and the Satellite Analysis Branch (SAB) of NESDIS classified it as a T7.0, which would support Category 5 winds. Since that time, there has been a slight warming of the cloud tops surrounding the eye, but there is no strong indication of an eyewall replacement cycle, yet.  It’s possible that Vongfong may still strenghten some in the next 12-24 hours.

 

MTSAT2 infrared imagery with GLD-360 Lightning Density overlaid at 30 min increments for Super Typhoon Vongfong.

MTSAT2 infrared imagery with GLD-360 Lightning Density overlaid at 30 min increments for Super Typhoon Vongfong.

The satellite animation above shows Vongfong’s rapid organization overnight with intermittent lightning bursts in the eyewall during the rapid intensification.  Typically, hurricanes and typhoons don’t exhibit much lightning due to the lack of convective available potential energy (CAPE) and dry air near the strongest thunderstorms.  During intense thunderstorm growth, most notably in the outer rain bands, there can be some graupel (soft hail/snowballs) which supports lightning, but the inner core is usually quieter (of course, this varies based on basin).  We have seen this before in the West Pacific (see posts on Haiyan and Rammasun).

89GHz RGB image from AMSR-2 on JAXA valid on 10/07/14.

89GHz RGB image from AMSR-2 on JAXA valid on 10/07/14.

89GHz RGB courtesy of GMI on GPM valid on 10/07/14.

89GHz RGB image from GMI on GPM valid on 10/07/14.

The two microwave image passes above show the convective structure of Vongfong under the clouds where the red coloring indicates heavier precipitation or convection.  These high resolution microwaves images are used by JTWC, SAB, and the National Hurricane Center when classification are being made, especially for fixing the initial center positions.

89 GHz RGB image from TRMM with GLD-360 lightning strikes overlaid valid on 10/07/14.

89 GHz RGB image from TRMM with GLD-360 lightning strikes overlaid valid on 10/07/14.

Another interesting way of looking at the microwave imagery is with lightning overlaid.  The lightning strikes for the previous 30 minutes were overlaid on this 0719 UTC Tropical Rainfall Measurement Mission (TRMM) satellite pass.  As you can see, the lightning matches up quite well with the red colorings (convection).  Notice the lightning cluster in the southeast eyewall!

The Day-Night Band image from VIIRS on S-NPP valid at . Courtesy of Dan Lindsey (NESDIS/STAR)

The Day-Night Band image from VIIRS on S-NPP valid at 1703 UTC on 10/07/14. Courtesy of Dan Lindsey (NESDIS/STAR)

Finally, this incredible Day-Night Band (DNB) image was captured by the S-NPP satellite this afternoon.  That is not a traditional visible satellite image. . .that is from the moon light!  The Proving Grounds receive DNB imagery from NASA SPoRT and CIMSS on a routine basis to help forecasters identify significant features and help with center fixes of tropical cyclones, similar to the microwave imagery.

I hope you enjoyed this post!  Thanks for reading!

Sandy ready to visit the Mid-Atlantic tonight

Posted by Michael Folmer on 10/29/2012
Posted in: Microwave, MODIS, RGB, VIIRS. 2 Comments

This will be a short post to update you on some incredible satellite imagery that is assisting forecasters today. Some of it is very new and due to some incredible hard work behind the scenes at CIMSS/SSEC University of Wisconsin-Madison and NASA SPoRT, we have these available for the blogs and some of it in operations at the Hydrometeorological Prediction Center, the Ocean Prediction Center, the NESDIS Satellite Analysis Branch, and the Hurricane Center. Thank you everyone for your help!

Suomi NPP VIIRS Day-Night Band (DNB) composite of Sandy courtesy of CIMSS/SSEC/University of Wisconsin-Madison valid on 10/29/12.

The Suomi NPP VIIRS Day-Night Band image above shows Sandy overnight with a “visible” like image thanks to our full moon. This same full moon is already aiding in the astronomical high tides on top of the storm surge and large fetch. At last report, Atlantic City is completely underwater by a few feet and chunks of boardwalk are destroyed up and down the NJ coastline.

GOES-14 SRSO of Sandy on 10/29/12 with GLD-360 1-min lightning overlaid courtesy of Vaisala. Click on image to animate.

The GOES-14 Super Rapid Scan Operations (SRSO) is running at the NCWCP today to assist the forecasters with 1-min imagery at 1 km resolution. This could help HPC, OPC, and SAB look for structural changes in Sandy as she makes her approach to shore this evening. Note the complete lack of cloud-to-ground lightning in the core of the storm, while you see occasional lightning strikes in the bands hundreds of miles to the east. This is definitely one of the larges storms I’ve seen in my relatively short career!

GOES-Sounder RGB Air Mass product valid at 15z on 10/29/12 courtesy of CIRA and NASA SPoRT.

Last week I started to describe some of the upper-level features that would play a role in moving Sandy towards the East Coast. Today, the red “L” indicates the approximate location of the upper-level low that is cutting off and moving Sandy towards the coast. The black “L” is Sandy and shows the proximity. The red area highlighted shows the dry, stratospheric air on the periphery of Sandy, but notice how there is no sign of that over the hurricane? Sandy has been able to re-attain its more tropical look which has led to significant deepening and increases in wind. This tool has been used at HPC to help with the placement and timing of the features when compared to model solutions.

MODIS RGB Air Mass product valid at 0709z on 10/29/12 which shows a much higher resolution image at ~2 km. Image courtesy of NASA SPoRT.

The MODIS RGB Air Mass product above shows a much higher resolution image of the Sandy-Upper-low interaction. I again show the approximate location of the upper-low with the red “L” and the outlined area is the dry stratospheric air and notice there is more than in the previous image. A full transition to extratropical will occur tonight, but that doesn’t matter anymore as Sandy’s effects are already being felt even in DC and Baltimore.

The AMSR-2 image showing heavy rain in the blue area.

In addition to S-NPP, NOAA JPSS will be providing global data from the new Japanese AMSR-2 sensor to NOAA operational users later next year. AMSR-2 is the follow-on to AMSR-E which is on NASA’s AQUA satellite but failed last year. AMSR-2 will provide many capabilities including instantaneous rainfall rates as it flies over. The figure above is the 89V channel of AMSR-E, the blue area is associated with the heaviest rainfall rates from Sandy. Thank you to Mitch Goldberg from JPSS for providing me with this description! Special thanks to Fuzhong Weng and his team for providing us with this outstanding image.

If you are on the East Coast, be safe! For everyone else, I’m not sure I will be able to post anymore blogs for a while on here. I am leaving the reigns in the hands of Amanda Terborg (Satellite Liaison at the Aviation Weather Center) and Chris Siewert (Satellite Liaison at the Storm Prediction Center) to keep you all updated.

I would also like to give a shout-out to the forecasters at HPC, OPC and NHC along with the satellite analysts at SAB for doing a spectacular job during this historic event. I hope everyone that reads this understands the amount of pressure that is on a forecaster when trying to relay information to the public about the severity of what we are seeing and will see tonight. Thank you!

Thanks for reading!