Typhoon Roke

September 20th, 2011 |

 

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

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 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)

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

River valley fog in Pennsylvania

September 16th, 2011 |
1-km resolution MODIS fog product + 4-km resolution GOES-13 fog product

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

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

Hurricane Maria

September 15th, 2011 |
GOES-13 10.7 µm IR images

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

MODIS 0.65 µm visible channel and 11.0 µm IR channel images

GOES-15: improved spatial resolution water vapor channel

September 14th, 2011 |

 

GOES-11 6.7 µm (left) and GOES-15 6.5 µm (right) water vapor channel images (click image to play animation)

GOES-11 6.7 µm (left) and GOES-15 6.5 µm (right) water vapor channel images (click image to play animation)

McIDAS images of 8-km resolution GOES-11 6.7 µm and 4-km resolution GOES-15 6.5 µm water vapor channel data (above) demonstrated the advantage of improved spatial resolution for the detection of features and gradients in the water vapor imagery associated with a weak upper level low moving eastward across the southwestern US on 14 September 2010. GOES-15 is scheduled to replace GOES-11 as the operational GOES-West satellite in December 2011.

AWIPS images of the GOES-11 sounder Convective Available Potential Energy (CAPE) product (below) showed that the atmosphere was destabilizing in advance of the upper low, with CAPE values in the 1000-2000 J/kg range.

GOES-11 sounder Convective Available Potential Entegy (CAPE)

GOES-11 sounder Convective Available Potential Entegy (CAPE)

With the increasing instability and large scale lift ahead of the upper low, areas of thunderstorms developed over parts of Nevada, Arizona, and Utah, as seen on a MODIS 11.0 µm IR image with an overlay of cloud-to-ground lightning strikes (below). About an hour after the time of the MODIS image, one of these storms produced 1.0-inch diameter hail that covered the ground near Munds in northern Arizona (SPC storm reports).

MODIS 11.0 µm IR image + cloud-to-ground lightning strikes

MODIS 11.0 µm IR image + cloud-to-ground lightning strikes

CIMSS participation in GOES-R Proving Ground activities includes making a variety of MODIS and additional GOES Sounder images and products available for National Weather Service offices to add to their local AWIPS workstations. Currently there are 49 NWS offices receiving MODIS imagery and products from CIMSS.