POES AVHRR 3.7 µm shortwave IR image

An AWIPS image of POES AVHRR 3.7 µm shortwave IR data (above) revealed a large number of fire “hot spots” (black to red to yellow pixels) across much of eastern Kansas on 12 April 2011. The majority of these were grassland fires.

On the following day (13 April 2011), a well-defined area of dense smoke aloft could be seen stretching from Missouri into southwestwen Iowa on a MODIS 0.65 µm visible channel image (below).

MODIS 6.5 µm visible channel image

====================================

GOES-13 0.63 µm visible channel images (click image to play animation)

GOES-13 0.63 µm visible images (above; click image to play animation) showed that the dense smoke feature moved very little during the day. An overlay of NAM12 850 mb winds (below) indicated that light southwesterly winds in the morning transitioned to a more organized southeasterly flow as a low-level cyclonic circulation moved southward across Nebraska into Kansas.

GOES-13 visible images + NAM12 850 mb winds

A MODIS true color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (below; displayed using Google Earth) provided a better view of the smoke pall aloft as the northern end wrapped around the low-level cyclonic circulation.

MODIS true color RGB image (displayed using Google Earth)

MODIS Aerosol Optical Depth (AOD) products from the IDEA site (below) showed very high ADO values  (orange to red color enhancement) associated with this smoke feature.

MODIS Aerosol Optical Depth (AOD) products

View only this post Read Less

MODIS false color RGB image (displayed using Google Earth)

A MODIS false color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (above; courtesy of Kathy Strabala, CIMSS) showed the areal extent of the unprecedented overland flooding that was occurring along parts of the Red River in North Dakota on 11 April 2011. Spring snow-melt along with recent heavy rainfall were contributing to the flooding. Interstate 29 north of Fargo was closed on the previous day due to rising floodwater covering the roadway.

AWIPS images of 1-km resolution MODIS 0.65 µm visible channel and 2.1 µm near-IR “snow/ice” channel data (below) was also useful for helping to highlight the location of the flooded areas. Both water and frozen lakes appear as very dark features on the 2.1 µm “snow/ice” channel image — but the frozen lakes are brighter white on the visible image.

MODIS 0.65 µm visible image + MODIS 2.1 µm near-IR "snow/ice" image

A comparison of 250-meter resolution MODIS true color and false color RGB images (below) offered a more detailed view of the flooding in the Fargo and Grand Forks areas. The flooded areas exhibited a “muddy” light brown appearance on the true color image. Farther to the west, the still-frozen Devils Lake (whose water level had reached a new record high level) and portions of northeastern North Dakota that still had snow cover (as much as 6 inches remaining on the ground) could also be seen (snow cover and frozen lakes appeared as lighter blue to cyan features on the false color image).

250-meter resolution MODIS true color and false color RGB images

View only this post Read Less

Supercell thunderstorms developed along and ahead of an advancing cold frontal boundary and moved rapidly eastward across parts of northern and central Wisconsin on 10 April 2011. These severe storms produced  widespread damaging winds, large hail (up to 3.0 inches in diameter), and a significant number tornadoes (see: NWS La Crosse | NWS Green Bay | NWS Milwaukee | SPC Storm Reports). With 11 tornadoes confirmed so far, this was the largest single-day April tornado outbreak on record in Wisconsin.

GOES-13 0.63 µm visible images (click image to play animation)

McIDAS images of GOES-13 0.65 µm visible channel data (above; click image to play animation; also available as a QuickTime movie) showed a number of overshooting tops associated with these severe thunderstorms. The corresponding GOES-13 10.7 µm IR images (below; click image to play animation; also available as a QuickTime movie) showed the cold cloud top IR brightness temperatures (as cold as -67º C at 01:33 UTC), as well as a few enhanced-v and cold/warm couplet signatures.

GOES-13 10.7 µm IR images (click image to play animation)

A comparison of a 1-km resolution NOAA-15 AVHRR 10.8 µm IR image with the corresponding 4-km resolution GOES-13 10.7 µm IR image at 21:33 UTC (below) demonstrates the advantage of higher spatial resolution to aid in the detection of enhanced-v and cold/warm thermal couplet storm top signatures, as well as a more accurate depiction of the coldest cloud top IR brightness temperatures associated with the more vigorous overshooting tops (-71º C on the NOAA-15 AVHRR IR image, compared to -58º C on the GOES-13 IR image).

NOAA-15 AVHRR 10.8 µm IR and GOES-13 10.7 µm IR images at 21:33 UTC

An AWIPS GOES-13 0.65 µm visible image at 23:45 UTC (below) was particularly interesting — a few overshooting tops could be seen over central Wisconsin, as well as long shadows being cast upon the hazy boundary layer by a narrow line of developing convection to the southwest. Cloud-to-ground lightning strikes and storm reports (damaging winds, large hail, and tornadoes) are also overlaid on the visible image.

GOES-13 0.63 µm visible image + cloud-to-ground lightning strikes + storm reports

In an effort to try and locate a satellite signature of the damage path of the EF3-rated tornado that moved from Hamburg to Merrill to Gleason in north-central Wisconsin, a comparison of 250-meter resolution MODIS true color images from 10 April (a few hours before the tornado) and 12 April (2 days after the tornado) were used (below). However, the lack of a deep snow cover or dense vegetation in this area made it very difficult to identify the tornado damage path. Note that on 10 April — the day of the tornado outbreak — there still was some light snow cover just to the northwest of the tornado track, with some sites reporting 2-3 inches of snow remaining on the ground that morning.

MODIS true color images on 10 April and 12 April (displayed using Google Earth)

View only this post Read Less

MODIS Red/Green/Blue (RGB) image, created using Bands 07/02/01

A McIDAS false-color Red/Green/Blue (RGB) image (created using MODIS Bands 07/02/01) showed numerous “burn scars” (red-enhanced features) that remained from recent fire activity across eastern Kansas and eastern Oklahoma on 05 April 2011 (above). Previous blog posts displayed imagery of the fires as they were burning on 23 March and 11 March.

========== 06 APRIL UPDATE ==========

An AWIPS image of MODIS 3.7 µm shortwave IR data (below) revealed widespread fire “hot spots” (black to red to yellow color enhancement) as fire activity flared up once again across this region on 06 April 2011.

MODIS 3.7 µm shortwave IR image

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.

View only this post Read Less