MODIS Land Surface Temperature product

Much of the state of Florida experienced below-freezing temperatures on the morning of 04 January 2012. An AWIPS image of the 1-km resolution MODIS Land Surface Temperature (LST) product (above) showed that LST values of 32ª F and colder (blue color enhancement) extended far to the south at 07:27 UTC (02:27 am local time). There were even several pockets exhibiting LST values less than 20ª F (violet color enhancement), including a minimum of 10.7ª F just southwest of Gainesville (station identifier KGNV) in northern Florida, and 15.3ª F just to the west of Lake Okeechobee in southern Florida.

A map of minimum temperatures on the morning of 04 January (below) showed that the cold air had even moved as far south as Cuba, where lows in the 40s F were observed. In Florida, new record  low temperatures for the day included 18ªF at Tallahassee, 20ª F at Gainesville, 22ª F at Jacksonville, 33ª F at Melbourne, and 36ª F at Naples.

04 January 2011 minimum temperatures

View only this post Read Less

EUMETSAT Meteosat-9 Water Vapor (7.35 µm) images (click image to play animation)

A rapidly intensifying mid-latitude cyclone (named “Cyclone Ulli” by the Europeans | surface analysis) was responsible for a high wind event as it moved over Scotland on 03 January 2012. A sequence of EUMETSAT Meteosat-9 Water Vapor (7.35 µm) images (above) revealed two notable signatures: (1) the formation of a pronounced area of warm/dry water vapor brightness temperatures (bright yellow to orange color enhancement) over the open water north of Ireland, which indicated a strongly forced region of rapidly descending middle-tropospheric air, and (2) a classic “Sting Jet” signature (Monthly Weather Review | Wikipedia) which then moved eastward across Scotland. Just to the south of the sting jet signature, a wind gust of 78 knots (90 mph) was recorded at Glasgow at 08:20 UTC, followed by a wind gust of 70 knots (81 mph) at Edinburgh at 08:50 UTC.  There were additional reports of wind gusts in excess of 87 knots (100 mph) at non-METAR sites in Scotland.

The Sting Jet signature can also be seen in EUMETSAT Meteosat-9 Infrared (10.8 µm) images (Animated GIF) and EUMETSAT Meteosat-9 Visible (0.635 µm) images (Animated GIF).

A comparison of 1-km resolution NOAA-19 Visible (0.63 µm) and Infrared (10.8 µm) images at 12:54 UTC (below) showed the structure of the cyclone as it was centered over the North Sea between the British Isles and Norway.

NOAA-19 0.63 µm visible channel image + NOAA-19 10.8 µm IR channel image

Additional images of this Sting Jet event are available on the EUMETSAT and NASA Wide World of SPoRT sites.

View only this post Read Less

MODIS true color RGB image (viewed using Google Earth)

An interesting pattern of “snow streaks” across parts of Illinois, Indiana, and Kentucky was seen on a MODIS true color Red/Green/Blue (RGB) image from the SSEC MODIS Today site on 03 January 2012 — this pattern was caused by narrow cells of convective snowfall which propagated southeastward across the region on the previous day. The amount of snow on the ground was only a Trace to 1 inch, which allowed the snow streaks to quickly melt during the day.

View only this post Read Less

GOES-12 3.9 µm shortwave IR channel images (click image to play animation)

As a result of prolonged drought and a mid-summer heat wave across southern Chile, a number of wildfires were burning in parts of the region on 01 January – 02 January 2012 (surface analysis). GOES-12 3.9 µm shortwave IR images (above; click image to play animation) showed a number of fire “hot spots” (yellow to red color enhancement) between Concepcion (station identifier SCIE) and Chillan (station identifier SCCH) from the late afternoon on 01 January until the early morning hours on 02 January.

During the subsequent daytime hours, GOES-12 0.63 µm visible channel images (below; click image to play animation) revealed a long hazy smoke plume that was drifting northwestward out over the adjacent Pacific Ocean. As daytime heating increased, cumulus clouds with a few thunderstorms could also be seen developing farther inland over the higher terrain of the Andes Mountains.

GOES-12 0.63 µm visible channel images (click image to play animation)

Rawinsonde data from Santo Domingo (station identifier SCSN) at 12 UTC indicated that southeasterly winds existed near the top of the deep temperature inversion, between 741 hPa (2.6 km) and 700 hPa (3.1 km) — so this is likely the approximate altitude of the smoke plume seen drifting toward the northwest on the GOES-12 visible satellite imagery.

Santo Domingo, Chile rawinsonde data plot

A high-resolution MODIS true color image of the fire smoke plume can be seen on the NASA Earth Observatory site.

View only this post Read Less