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Strong extratropical cyclone in the Midwest and Great Lakes

A large and rapidly-deepening midlatitude cyclone (surface analyses) moved northeastward across the Midwest and Great Lakes on 24 February 2019. GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed the storm circulation that featured a pronounced dry slot — strong winds were widespread, with gusts of 60 knots or higher occurring... Read More

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly plots of surfave winds and gusts in knots [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly plots of surfave winds and gusts in knots [click to play MP4 animation]

A large and rapidly-deepening midlatitude cyclone (surface analyses) moved northeastward across the Midwest and Great Lakes on 24 February 2019. GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed the storm circulation that featured a pronounced dry slot — strong winds were widespread, with gusts of 60 knots or higher occurring in 16 states (WPC storm summary). New February records for lowest pressure were set in northern Michigan at Alpena (978.7 hPa) and Sault Ste. Marie (976.6 hPa). Blizzard conditions closed many interstates and highways across the Upper Midwest.

1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images (below) revealed the eastward motion of wind-driven ice across southern Lake Michigan.

GOES-16 "Red" Visible (0.64 µm) images, with hourly plots of surfave winds and gusts in knots [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm) images, with hourly plots of surfave winds and gusts in knots [click to play MP4 animation]

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River flooding in the Lower Mississippi and Tennessee River Valley

A toggle between Observed Precipitation and Percent of Normal Precipitation for the 30-day period ending at 12 UTC on 24 February 2019 (above) showed a large area that received 10-15 inches of rainfall — which was 200-400% of normal — across the Lower Mississippi River and Tennessee River Valleys.A before/after... Read More

30-day Precipitation and Percent of Normal Precipitation [click to enlarge]

30-day Precipitation and Percent of Normal Precipitation [click to enlarge]

A toggle between Observed Precipitation and Percent of Normal Precipitation for the 30-day period ending at 12 UTC on 24 February 2019 (above) showed a large area that received 10-15 inches of rainfall — which was 200-400% of normal — across the Lower Mississippi River and Tennessee River Valleys.

A before/after comparison of Terra MODIS False Color Red-Green-Blue (RGB) images from 25 January and 24 February 2019 (below) revealed the extensive area of flooding that resulted. Flooded areas appear as varying shades of blue on the False Color imagery (source).

Terra MODIS False Color RGB images from 25 January and 24 February 2019 [click to enlarge]

Terra MODIS False Color RGB images from 25 January and 24 February 2019 [click to enlarge]

In a comparison of Terra MODIS True Color and False Color RGB images from 24 February (below), many of the flooded rivers exhibit a tan-colored appearance in the True Color image due to large amounts of sediment suspended in the water.

Terra MODIS True Color and False Color RGB images from 24 February [click to enlarge]

Terra MODIS True Color and False Color RGB images from 24 February [click to enlarge]

A Flood Map derived using NOAA-20 VIIRS data (below) quantitatively showed the extent of the flooding. CIMSS scientists Jay Hoffman and William Straka contributed to the development of this food monitoring product.

NOAA-20 VIIRS Flood Map [click to enlarge]

NOAA-20 VIIRS Flood Map [click to enlarge]

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Lake effect snow in Nevada

Lake Effect Snow off Pyramid Lake will affect the morning commute for much of Reno-Sparks. Accumulations up 3 inches with locally heavier amount through noon today. Slow down when in the band. #LakeEffect pic.twitter.com/ul2RJRb46F — NWS Reno (@NWSReno) February 21, 2019 GOES-17 (GOES-West) “Clean” Infrared Window (10.3 µm) images (above) showed an... Read More


GOES-17

GOES-17 “Clean” Infrared Window (10.3 µm) images [click to play animation | MP4]

GOES-17 (GOES-West) “Clean” Infrared Window (10.3 µm) images (above) showed an unusual lake effect snow feature downwind of Pyramid Lake in northwestern Nevada on 21 February 2019 — the surface visibility dropped to 0.5 mile with moderate snow as ihe lake effect cloud moved over Reno-Tahoe International Airport around 16 UTC. Prior to that, the lake effect snow also affected portions of Interstate 80 in the Patrick area.

A morning overpass of the NOAA-19 satellite provided a 1-km resolution Infrared Window (10.8 µm) image of the lake effect cloud at 1254 UTC (below). The coldest cloud-top infrared brightness temperature on that image was -46ºC.

NOAA-19 AVHRR Infrared Window (10.8 µm) image at 1254 UTC [click to enlarge]

NOAA-19 AVHRR Infrared Window (10.8 µm) image at 1254 UTC [click to enlarge]

GOES-17 cloud-top infrared brightness temperatures associated with this feature were as cold as -47ºC just after 15 UTC, which were very close to the tropopause temperature of -47.9ºC on 12 UTC rawinsonde data from Reno (below).

Plot of 12 UTC rawinsonde data from Reno, Nevada [click to enlarge]

Plot of 12 UTC rawinsonde data from Reno, Nevada [click to enlarge]

Although clouds often prevented a good view of Lake Pyramid, Terra MODIS Sea Surface Temperature values of 42º and 43ºF were sampled on 11 and 16 February (below). With a northerly flow of air having temperatures around 20ºF across such warm water, significant boundary layer instability was generated to aid the growth of the lake effect cloud feature.

Terra MODIS Sea Surface Temperature product on 11 and 16 February [click to enlarge]

Terra MODIS Sea Surface Temperature product on 11 and 16 February [click to enlarge]

Although the view angle from GOES-16 (GOES-East) was rather large, a Land Surface Temperature pixel mapped to the northern portion of the lake had a value of 39.3ºF at 1701 UTC (below).

GOES-16 Land Surface Temperature product at 1701 UTC [click to enlarge]

GOES-16 Land Surface Temperature product at 1701 UTC [click to enlarge]

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Typhoon Wutip in the West Pacific Ocean

VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 at 1502 UTC (above) and from Suomi NPP at 1552 UTC (below) showed Category 2 Typhoon Wutip in the West Pacific Ocean (southeast of Guam) on 21 February 2019. With Moon in the Waning Gibbous phase (at... Read More

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1502 UTC [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1502 UTC [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 at 1502 UTC (above) and from Suomi NPP at 1552 UTC (below) showed Category 2 Typhoon Wutip in the West Pacific Ocean (southeast of Guam) on 21 February 2019. With Moon in the Waning Gibbous phase (at 95% of Full), ample illumination was provided to highlight the “visible image at night” capability of the Day/Night Band.

Notable features included deep convection near the storm’s center of circulation (with the presence of subtle cloud-top gravity waves), and transverse banding along the eastern periphery of the cold central dense overcast. Bright pixels seen in the Suomi NPP Day/Night Band image were the result of clouds being illuminated by lightning activity. VIIRS images courtesy of William Straka, CIMSS.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1552 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1552 UTC [click to enlarge]

===== 22 February Update =====

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Typhoon Wutip intensified to a Category 3 storm on 22 February (ADT | SATCON) — rapid scan JMA Himawari-8 Infrared Window (10.4 µm) images at 2.5 minute intervals (above) revealed cloud-top infrared brightness temperatures of -90ºC and colder (yellow pixels surrounded by darker purple) shortly after 00 UTC. Multiple convective bursts developed around the center of circulation, and evidence of eye formation was seen for a short time beginning around 1137 UTC.

Himawari-8 “Red” Visible (0.64 µm) images of Wutip (below) showed that a distinct cloud-free eye did not form during that time period.

Himawari-8 "Red" Visible (0.64 µm) images [click to play MP4 animation]

Himawari-8 “Red” Visible (0.64 µm) images [click to play MP4 animation]

A DMSP-17 SSMIS Microwave (85 GHz) image from the CIMSS Tropical Cyclones site (below) showed a nearly complete ring of strong convection around the eye region at 0916 UTC. A 24-hour animation of MIMIC-TC morphed microwave imagery is available here.

DMSP-17 SSMIS Microwave (85 GHz) image [click to enlarge]

DMSP-17 SSMIS Microwave (85 GHz) image [click to enlarge]

Prior to becoming a typhoon, Wutip had been moving over water with warm Sea Surface Temperatures and high Ocean Heat Content values (below).

Sea Surface Temperature and Ocean Heat Content [click to enlarge]

Sea Surface Temperature and Ocean Heat Content [click to enlarge]

===== 23 February Update =====

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

2.5-minute rapid scan Himawari-8 Infrared Window (10.4 µm) images (above) revealed the formation of a large and well-define eye with an annular eyewall structure as Wutip rapidly intensified (ADT | SATCON) to Category 4 Super Typhoon status on 23 February. Mesovortices could be seen rotating within the eye. Wutip became the most intense February typhoon on record in the Northwest Pacific basin.

In a toggle between NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1602 UTC (below), these mesovortices were also apparent — with the help of reflected moonlight — in the Day/Night Band.

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1604 UTC [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1604 UTC [click to enlarge]

As noted in a 21 UTC discussion from the JTWC, Wutip had a well-defined poleward outflow channel within the upper troposphere (below), which was a favorable factor for its intensification.

Himawari-8 Water Vapor (6.9 µm) images with plots of middle/upper-tropospheric derived motion winds [click to enlarge]

Himawari-8 Water Vapor (6.9 µm) images with plots of middle/upper-tropospheric derived motion winds [click to enlarge]

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