November 19th, 2009
GOES-10 10.7 µm IR images
McIDAS images of the GOES-10 10.7 µm IR channel (above) showed very cold cloud top temperatures associated with a large Mesoscale Convective Complex (MCC) that developed over northern Argentina and moved across Uruguay and into far southern Brazil on 19 November 2009. The MCC exhibited unusually cold IR brightness temperature values, as low as -89º C (dark purple color enhancement) at 04:58 UTC. In addition, early in the animation you can see several “enhanced-v” signatures on the IR imagery — this satellite signature indicates that severe convective storms have a high potential for producing damaging winds, large hail, or tornadoes. There were media reports of a tornado and hail in parts of Uruguay, and according to the Metsul Blog this MCC produced very strong winds (gusting to 82 mph or 36.8 meters per second) and heavy rainfall (2.8 inches or 70 mm in 2 hours) as the storm moved into the Rio Grande do Sul region of southern Brazil.
GOES-10 (launched in 1997) is currently positioned in orbit at approximately 60 degrees West longitude in support of the Earth Observation Partnership of the Americas EOPA project or GEOSS Americas — however, due to end-of-life fuel conditions, GOES-10 will cease operations on 01 December 2009.
Posted in GOES-10, Severe convection | Comments Off
November 19th, 2009
MIMIC Total Precipitable Water product
AWIPS images of the MIMIC Total Precipitable Water (TPW) product (above) revealed the formation of a long “atmospheric river” of moisture over the North Atlantic Ocean during the 17-19 November 2009 period. MIMIC TPW values were as high as 60 mm (darker orange color enhancement) within the moisture plume.
The surface analysis (below) showed that this moist plume was along and ahead of a cold front that was trailing southward from a deepening mid-latitude cyclone. This plume of moisture was contributing to very heavy rainfall and significant flooding over parts of the United Kingdom — Seathwaite reported a 24-hour rainfall amount of 12.36 inches (314 mm), which if confirmed as accurate will set a new record for 24-hour precipitation in the UK (UK Met Office).
MIMIC TPW with surface analysis
A composite of GOES-12 and Meteosat-9 water vapor imagery (below) suggested that this long atmospheric river tapped into a pocket of deep tropical moisture (associated with the remnants of what was formerly Hurricane/Tropical Storm Ida), and was then brought northward within the warm conveyor belt in advance of the deepening cyclone over the North Atlantic Ocean.
GOES-12 and Meteosat-9 water vapor imagery
The Blended Total Precpitable Water – Percent of Normal product (below) indicated that this moist plume was rather anomalous for the season over the North Atlantic region, containing values of TPW that exceeded 200% of normal (yellow color enhancement).
Blended Total Precipitable Water - Percent of Normal
Posted in AWIPS, GOES-12, Heavy rain / flooding, Meteosat, POES | Comments Off
