CIMSS celebrates 4 years of providing MODIS data in AWIPS to NWS users

July 23rd, 2010 |
AWIPS menu of 1-km resolution MODIS products from CIMSS

AWIPS menu of 1-km resolution MODIS products from CIMSS

July 2010 marks the 4 year anniversary of the point when CIMSS  first began to provide MODIS images and products to National Weather Service (NWS) users in an AWIPS format. These MODIS images and products are available for interested NWS offices to add to their local AWIPS workstations via Unidata LDM subscription. A screen capture of the AWIPS menu of 1-km resolution MODIS products is shown above, with a sample of those products shown below over the southeastern US on 23 July 2010 (when Tropical Storm Bonnie happened to be moving across southern Florida and weakening to a Tropical Depression). In addition, there is also a 1-km resolution fog/stratus product (available only at night).

This MODIS in AWIPS project has been a critical component of the CIMSS contribution to the GOES-R Proving Ground effort — and along with extensive user training, has been a successful demonstration of the “Research to Operations” concept.

1-km resolution MODIS images and products available from CIMSS

1-km resolution MODIS images and products available from CIMSS

In addition to supplying the MODIS images and products, CIMSS also includes a MODIS Orbit Itinerary Viewer tool that is available from the AWIPS menu to assist the users in planning when to expect MODIS image availability on any given day. Also, for NWS users in Wisconsin, 250-meter resolution MODIS true color images are also available for viewing from the AWIPS menu.

AWIPS menu of 4-km resolution MODIS products from CIMSS

AWIPS menu of 4-km resolution MODIS products from CIMSS

Similarly, a screen capture of the AWIPS menu of MODIS 4-km resolution products is shown above, with those corresponding MODIS products shown below.

4-km resolution MODIS products available in AWIPS from CIMSS

4-km resolution MODIS products available in AWIPS from CIMSS

In an effort to continually improve the quality of the MODIS products being delivered, a recent development has been the correction of the “bow-tie” image artifacts that affect the outer edges of the MODIS scan swath (due to the scanning strategy of the MODIS instrument). In order to most effectively perform this bow-tie image correction, CIMSS has chosen to employ the MODIS Swath Reprojection Tool (MRTSwath) that is supported by NASA. Several examples of how the image bow-tie correction process performs are shown below. (Notice to NWS MODIS users: the bow-tie correction will be applied to all 1-km resolution MODIS images and products distributed by CIMSS beginning 27 July 2010).

MODIS visible images (with and without bow-tie correction)

MODIS visible images (with and without bow-tie correction)

MODIS IR images (with and without bow-tie correction)

MODIS IR images (with and without bow-tie correction)

MODIS Land Surface Temperature product images (with and without bow-tie correction)

MODIS Land Surface Temperature product images (with and without bow-tie correction)

MODIS Sea Surface Temperature product images (with and without bow-tie correction)

MODIS Sea Surface Temperature product images (with and without bow-tie correction)

MODIS fog/stratus product images (with and without bow-tie correction)

MODIS fog/stratus product images (with and without bow-tie correction)

Largest US hailstone on record in central South Dakota

July 23rd, 2010 |
GOES-13 (top) and GOES-15 (bottom) 10.7 µm IR images

GOES-13 (top) and GOES-15 (bottom) 10.7 µm IR images

McIDAS images of GOES-13 and GOES-15 10.7 µm IR images (above) showed the development of severe thunderstorms that produced very large hail, tornadoes, and damaging surface winds (SPC storm reports) in central South Dakota on 23 July 2010. This storm produced the largest US hailstone on record: 8 inch diameter, 18.6 inch circumference, 1.9375 pound weight — photos of the record-setting largest hailstone were taken by staff from the Aberdeen, South Dakota NWS forecast office. The coldest cloud top IR brightness temperatures were -71º C (darker black color enhancement) at 23:25 and 23:32 UTC. Since the GOES-13 satellite had been placed into Rapid Scan Operations (RSO), images were available as often as every 5-10 minutes (as opposed to every 15 minutes via the routine image scan schedule on GOES-15).

The corresponding GOES-13 and GOES-15 0.63 µm visible channel images (below) displayed a well-defined storm top anvil with distinct overshooting tops (GOES-13 visible images only: Animated GIF). Prior to convective development, the appearance of the quasi-stationary low-level parallel cloud bands suggests that there was strong warm air advection into the region from the southwest (HPC surface forecast).

GOES-13 (top) and GOES-15 (bottom) 0.63 µm visible images

GOES-13 (top) and GOES-15 (bottom) 0.63 µm visible images

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GOES-13 Sounder Total Precipitable Water (TPW) product

GOES-13 Sounder Total Precipitable Water (TPW) product

AWIPS images of the GOES-13 Sounder Total Precipitable Water (above) and Lifted Index (below) depicted a broad axis of moisture and instability that extended northwestward into central South Dakota on that day.

GOES-13 Sounder Lifted Index (LI) product

GOES-13 Sounder Lifted Index (LI) product

A comparison of the 1-km resolution GOS-13 0.63 µm visible image and the 4-km resolution GOES-13 10.7 µm IR image at 22:45 UTC (around the time of a report of 85 mph surface winds) is seen below. The apparent offset between the location of the overshooting top and the location of the surface wind gust is due in part to parallax error (a result of the large viewing angle from the GOES-13 satellite, which is positioned over the Equator at 75º West longitude).

GOES-13 visible and IR images at 22:45 UTC (near the time of a 85 mph wind gust)

GOES-13 visible and IR images at 22:45 UTC (near the time of a 85 mph wind gust)

A comparison of the 1-km resolution 0.63 µm GOES-13 visible image and the 4-km resolution 10.7 µm IR image at 23:10 UTC (around the time of a report of “softball size” 4.25 inch diameter hail) is shown below.

GOES-13 visible and IR images at 23:10 UTC (near the time of 4.25 inch diameter hail)

GOES-13 visible and IR images at 23:10 UTC (near the time of 4.25 inch diameter hail)

As noted above, the coldest cloud top IR brightness temperatures observed for this storm were -71º C — according to the rawinsonde profile data from Rapid City, South Dakota (below) this temperature corresponded to an altitude of around 55,000 feet or 16,800 meters.

Rawinsonde profile from Rapid City SD at 00 UTC on 24 July

Rawinsonde profile from Rapid City SD at 00 UTC on 24 July

Tropical Storm Bonnie downgraded to a Tropical Depression

July 23rd, 2010 |
GOES-13  0.63 µm visible images

GOES-13 0.63 µm visible images

GOES-13 0.63 µm visible images (above) and GOES-13 10.7 µm IR images (below) from the CIMSS Tropical Cyclones site showed Tropical Storm Bonnie crossing southern Florida on 23 July 2010.

GIES-13 10.7 µm IR images

GIES-13 10.7 µm IR images

Bonnie was encountering increasing amounts of southeasterly deep layer (850-200 hPa) wind shear (below), which was acting to displace the strongest convection to the north and northwest of the low-level center of the tropical cyclone.

GOES-13 IR image + Deep layer wind shear

GOES-13 IR image + Deep layer wind shear

Hourly Atmospheric Motion Vectors (AMVs) produced using GOES-13 and Meteosat-9 data (below) showed that Bonnie was being steered northwestward by the flow between a strong ridge over the southeastern US and an upper level low over the western Gulf of Mexico.

Hourly GOES-13 + Meteosat-9 water vapor winds

Hourly GOES-13 + Meteosat-9 water vapor winds

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MODIS 0.65 µm visible + 11.0 µm IR images

MODIS 0.65 µm visible + 11.0 µm IR images

AWIPS images of 1-km resolution visible and IR channel data from MODIS (above) and POES AVHRR (below) show Bonnie as it moved across the Florida peninsula and weakened from a Tropical Storm to a Tropical Depression.

AVHRR 0.63 µm visible + 10.8 µm IR images

AVHRR 0.63 µm visible + 10.8 µm IR images