GOES-15 0.63 µm visible channel images (click image to play animation)

GOES-15 0.63 µm visible channel images  (above; click image to play animation) showed the rather small but very distinct eye of Category 4 Hurricane Hilary in the Eastern North Pacific Ocean on 23 September 2011. GOES-15 (the newest in the series of GOES N/O/P satellites, launched and tested in 2010) is scheduled to replace GOES-11 as the operational GOES-West satellite in December 2011.

During this same time period on 23 September, the GOES-11 satellite was placed into Super Rapid Scan Operations (SRSO) mode, providing bursts of data at 1-minute intervals. Magnified versions of GOES-11 0.65 µm visible channel images (below; click image to play animation; also available as a QuickTime movie) revealed that at times there were multiple mesovortices within the eye of Hurricane Hilary. Larger-scale (zoomed-out) views of GOES-11 SRSO Water Vapor, Visible, and IR channel images are available from CIRA/RAMMB.

GOES-11 0.65 µm visible channel SRSO images (click image to play animation)

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MTSAT-2 10.8 µm IR channel images (click image to play animation)

MTSAT-2 10.8 µm IR channel images (above; click image to play animation) showed Category 4 Typhoon Roke as it approached Japan during the 19 September – 20 September 2011 period. Roke exhibited a well-defined eye during this time. Massive evacuations were urged by the Japanese government as this strong tropical cyclone approached major population centers in southern Japan.

On an MTSAT-2 IR image with surface and ship reports plotted from the CIMSS Tropical Cyclones site (below), the large radius of strong winds could be seen from the ship report of 50 knots a fair distance east of the storm center.

MTSAT-2 IR image + surface and ship reports

MTSAT-2 0.72 µm visible channel images (below; click image to play animation) showed the eye on 20 September — and there was a hint of meso-vortices within the eye of Roke on the 05:01 UTC visible image.

MTSAT-2 0.72 µm visible channel images (click image to play animation)

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1-km resolution MODIS fog product + 4-km resolution GOES-13 fog product

The early morning area forecast discussion issued by the National Weather service office at State College, Pennsylvania mentioned that river valley fog was being detected by the MODIS fog/stratus product:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
526 AM EDT FRI SEP 16 2011

.SYNOPSIS...
A LARGE HIGH PRESSURE SYSTEM OVER THE GREAT LAKES WILL BUILD SLOWLY EAST TO NEW ENGLAND BY SUNDAY AND MONDAY. A DYING COLD FRONT WILL LIKELY PUSH INTO THE REGION LATE MONDAY OR TUESDAY. A DIGGING TROF AND ASSOCIATED SLOW MOVING COLD FRONT COULD AFFECT THE REGION BY LATE NEXT WEEK.

.NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY AM MODIS 11-3.7UM IMAGERY SHOWING DENDRITIC PATTERN OF FOG IN THE DEEP RIVER VALLEYS OF THE ALLEGHENY MTNS.

A comparison of AWIPS images of the 1-km resolution MODIS fog/stratus product with the corresponding 4-km resolution GOES-13 fog/stratus product (above) demonstrated the advantage of higher spatial resolution for detecting such small-scale features. A subtle fog signal was beginning to show up at this time in the GOES-13 fog/stratus product image, but it was difficult to tell whether it was due to noise or actual fog features.

About an hour and 15 minutes later, a similar comparison using a 1-km resolution POES AVHRR fog/stratus image and the corresponding 4-km resolution GOES-13 fog/stratus product image (below) showed that while the fog signal had become better defined by this time on the GOES-13 image, the POES AVHRR image again showed the river valley fog features with much greater clarity.

1-km resolution POES AVHRR fog product + 4-km resolution GOES-13 fog product

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GOES-13 10.7 µm IR images

Maria intensified on 15 September 2011 to become the third hurricane of the 2011 season in the Atlantic Basin — convective bursts during this time period were seen on 4-km resolution GOES-13 10.7 µm IR images from the CIMSS Tropical Cyclones site (above).

AWIPS images of 1-km resolution MODIS 0.65 µm visible channel and 11.0 µm IR channel data (below) displayed cloud top IR brightness temperatures as cold as -84º C (darker purple color enhancement) associated with a couple of the convective bursts, and a curved convective band wrapping around the northern portion of what appeared to be the eye of Maria.

MODIS 0.65 µm visible channel and 11.0 µm IR channel images

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