Hurricane Kenneth

November 20th, 2011 |
GOES-11 0.65 µm visible channel images + ship reports

GOES-11 0.65 µm visible channel images + ship reports

According to the National Hurricane Center, on 20 November 2011 Tropical Storm Kenneth became the latest-forming named tropical storm in the eastern North Pacific basin since Hurricane Winnie formed on 04 December 1983. GOES-11 0.65 µm visible channel images from the CIMSS Tropical Cyclones site (above) showed a well-defined circulation, with a ship report of tropical storm force winds north of the storm center.

The corresponding GOES-11 10.7 µm IR images (below) showed a trend of increasing convection withing the northern semicircle of the storm.

GOES-11 10.7 µm IR images + ship reports

GOES-11 10.7 µm IR images + ship reports

AWIPS images of the MIMIC Total Precipitable Water (TPW) product (below; click image to play animation) indicated that TPW values associated with Tropical Storm Kenneth were in the 50-60 mm range (darker orange colors), as rich moisture was sill in place along the Inter-Tropical Convergence Zone (ITCZ) / Monsoon Trough.

MIMIC Total Precipitable Water (TPW) product (click image to play animation)

MIMIC Total Precipitable Water (TPW) product (click image to play animation)

======== 21 November Update ========

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

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

Kenneth was upgraded to a Hurricane on 21 November. GOES-15 0.63 µm visible channel images (above; click image to play animation) showed a ragged eye forming as curved convective bands wrapped around the center of the tropical cyclone. Kenneth was able to intensify in part because it was in an environment that possessed uncharacteristically low values of deep layer wind shear (below).

GOES-11 10.7 µm IR image + deep layer wind shear

GOES-11 10.7 µm IR image + deep layer wind shear

======== 22 November Update ========

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

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

Hurricane Kenneth strengthened to a Category 4 storm on 22 November, becoming the most intense major hurricane to form so late in the season in the satellite era. GOES-15 0.63 µm visible channel images (above; click image to play animation) showed the well-defined eye of Kenneth.

Snow cover increasing across the north-central US

November 20th, 2011 |
MODIS 0.65 µm visible channel image + MODIS Red/Green/Blue (RGB) false color image

MODIS 0.65 µm visible channel image + MODIS Red/Green/Blue (RGB) false color image

A comparison of an AWIPS image of 1-km resolution MODIS 0.65 µm visible channel data with the corresponding MODIS false color Red/Green/Blue (RGB) image created using the 2.1 µm “snow/ice channel” (above) showed that snow cover was beginning to increase in areal extent across parts of the north-central US on 20 November 2011. This example also demonstrates the utility of RGB imagery for helping to discriminate between snow cover (which shows up as shades of red on the RGB image) and supercooled water droplet clouds (which show up as varying shades of white). Snow depths at the time included 11 inches at Mount Rushmore, South Dakota, 10 inches at Rice, Minnesota and 5 inches at Minot, North Dakota.

MODIS false color RGB images created using data from consecutive overpasses of the Terra (17:22 UTC) and Aqua (19:03 UTC) satellites (below) also show the movement of the low cloud features during that period.

MODIS false color Red/Green/Blue (RGB) images

MODIS false color Red/Green/Blue (RGB) images

As pointed out in the NWS Minneapolis Area Forecast Discussion, the swath of fresh snow cover would have an impact on daily high and low temperatures at locations where the snow was deepest. An AWIPS image of the 1-km resolution MODIS Land Surface Temperature (LST) product (below) revealed that LST values were in the 0º F to +10º F range (cyan to blue color enhancement) over the areas with snow cover, in contrast to LST values in the 30s F (green color enhancement) over adjacent areas with bare ground.

MODIS Land Surface Temperature product

MODIS Land Surface Temperature product

CIMSS participation in GOES-R Proving Ground activities includes making a variety of MODIS 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.