Heavy Rainfall in Southeast Texas

May 27th, 2016

GOES-13 Infrared Window (10.7 µm) images [click to play animation]

GOES-13 Infrared Window (10.7 µm) images [click to play animation]

4-km resolution GOES-13 (GOES-East) Infrared Window (10.7 µm) images (above) showed the cold cloud tops associated with training and back-building thunderstorms that produced very heavy rainfall (along with some hail and damaging winds) in parts of Southeast Texas during the 26 May27 May 2016 period. The images are centered on Brenham, Texas (station identifies K11R), where over 19 inches of rainfall was reported in a 24-hour period (NWS Houston PNS). Note the presence of very cold cloud-top IR brightness temperatures of -80º C or colder (violet color enhancement).

During the overnight hours, a comparison of Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0801 UTC or 3:01 am local time (below) revealed cloud-top gravity waves propagating northwestward away from the core of overshooting tops (which exhibited IR brightness temperatures as cold as -84º C) located just to the west of Brenham. Due to ample illumination from the Moon — which was in the Waning Gibbous phase, at 71% of Full — the “visible image at night” capability of the VIIRS Day/Night Band (DNB) was well-demonstrated. The bright white streaks seen on the DNB image are a signature of cloud-top illumination by intense lightning activity.

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

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

A time series plot of surface weather conditions at Brenham is shown below.

Time series plot of surface weather conditions at Brenham, Texas [click to enlarge]

Time series plot of surface weather conditions at Brenham, Texas [click to enlarge]

===== 28 May Update =====

Landsat-8 false-color RGB image [click to enlarge]

Landsat-8 false-color RGB image [click to enlarge]

A 30-meter resolution Landsat-8 false-color Red/Green/Blue (RGB) image viewed using the RealEarth web map server (above) showed widespread areas of inundation (darker shades of blue) along the Brazos River and some of its tributaries, just to the east and north of Brenham, Texas.

 

Cyclone Roanu, and a new all-time high temperature record set in India

May 21st, 2016

INSAT-3D Infrared Window (10.8 µm) images, with hourly surface weather symbols [click to play MP4 animation]

INSAT-3D Infrared Window (10.8 µm) images, with hourly surface weather symbols [click to play MP4 animation]

Cyclone Roanu (01B) was the first tropical cyclone of the 2016 North Indian Ocean season, with a northeastward track just off the east coast of India during the 18-21 May period. The storm moved over very warm waters, with sea surface temperature values of 30-31º C, but moderate amounts of deep-layer wind shear prevented the storm from rapidly intensifying (ADT | SATCON). INSAT-3D Infrared Window (10.8 µm) images (above; also available as a large 79 Mbyte animated GIF) showed that the storm exhibited a number of convective bursts with a large areal coverage of cloud-top IR brightness temperatures colder than -90ºC. Cyclone Roanu brought very heavy rainfall to Sri Lanka, coastal India, and Bangladesh.

As Roanu was moving along the east coast, very hot surface air temperatures were seen in the western portion of India on 19 May, with many sites reporting temperatures in excess of 110ºF. The animation below shows hourly Infrared images with surface METAR reports, as viewed using RealEarth.

Hourly Infrared satellite images, with METAR surface reports [click to play animation]

Hourly Infrared satellite images, with METAR surface reports [click to play animation]

INSAT-3D Visible (0.65 µm) images, with hourly surface wind barbs (knots) and temperatures (ºF) [click to play animation]

INSAT-3D Visible (0.65 µm) images, with hourly surface wind barbs (knots) and temperatures (ºF) [click to play animation]

INSAT 3D Visible (0.65 µm) images with hourly surface temperatures in ºF (above) revealed temperatures as warm as 122ºF at Ahmadabad, at 10 UTC and 12 UTC; a plot of the time series of weather condition at Ahmadabad is shown below. Farther to the north at the city of Phalodi (whose location is denoted by the gray * symbol) a temperature of 123.8ºF or 51.0ºC was recorded, which set an all-time record for the highest temperature officially measured in India (the previous record was 50.6ºC, set in 1886 at Pachpadra)..

Time series plot of surface data for Ahmadabad, India [click to enlarge]

Time series plot of surface data for Ahmadabad, India [click to enlarge]

Large storm system over the western/central US

April 17th, 2016

GOES-14 Water Vapor (6.5 µm) images [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images (above; also available as a large 85 Mbyte animated GIF) showed the development of a large upper-level closed low centered over the western US during the 15 April17 April 2016 period. This large storm system was responsible for a wide variety of weather, ranging from heavy snow and high winds in the Rocky Mountains to heavy rainfall and severe weather from eastern Colorado to Texas (SPC storm reports: 15 April | 16 April | 17 April).

Strong storm over the Upper Midwest and western Great Lakes

March 16th, 2016

GOES-13 Water Vapor (6.5 µm) images, with surface analyses [click to play animation]

GOES-13 Water Vapor (6.5 µm) images, with surface analyses [click to play animation]

A strong storm rapidly deepened as it moved northeastward across the Upper Midwest and western Great Lakes on 16 March 2016. GOES-13 Water Vapor (6.5 µm) images (above) showed the evolution of the system as the cloud shield expanded and became more elongated in a west-to-east orientation. On the previous day, this storm produced widespread hail and tornadoes from far eastern Iowa into northern and central Illinois (SPC storm reports).

A closer view of GOES-13 Visible (0.63 µm) images with METAR surface reports (below) revealed the strong winds caused by the tight pressure gradient — a peak wind gust of 61 mph was recorded at Waukesha in southeastern Wisconsin, with multiple power outages across the region caused by wind-related tree damage. Heavy rain (as much as 2-3 inches) produced some minor river flooding in various parts of Wisconsin; across northern Wisconsin, northeastern Minnesota, and the Upper Peninsula of Michigan the rain changed to snow, with as much as 18.5 inches accumulating at Redridge, Michigan, 13.0 inches at Lutsen, Minnesota, and 8.0 inches at Poplar and Sand Bay, Wisconsin. The weight of the wet snow was causing tree limbs to fall, with additional power outages being reported.

GOES-13 Visible (0.63 µm) images [click to play animation]

GOES-13 Visible (0.63 µm) images [click to play animation]

With the strong winds associated with this storm, there were also scattered pilot reports of moderate turbulence across the region, including 2 reports of severe turbulence over southern Wisconsin as seen below.

GOES-13 Water Vapor (6.5 µm) image, with pilot report of severe turbulence [click to enlarge]

GOES-13 Water Vapor (6.5 µm) image, with METAR surface reports and a pilot report of severe turbulence [click to enlarge]

GOES-13 Water Vapor image, with pilot report of severe turbulence [click to enlarge]

GOES-13 Water Vapor image, with METAR surface reports and a pilot report of severe turbulence [click to enlarge]