GOES-15 0.63 µm visible images

An isolated thunderstorm over southwestern Arizona during the afternoon hours on 17 August 2010 was responsible for a report of surface winds of 79 knots (91 mph) along with 0.80 inch of rain in 45 minutes near Ajo (SPC storm reports). McIDAS images of 1-km resolution GOES-15 0.63 µm visible channel data (above) showed the rapid development of this thunderstorm (along with several other storms across Arizona) — the time and location of the surface wind gust is annotated as “G79” on the 20:30 UTC image.

GOES-15 is currently providing imagery during its Post Launch Science Test; real-time GOES-15 imagery is available for viewing on the SSEC Geostationary Image Browser.

The corresponding 4-km resolution GOES-15 10.7 µm IR images (below) revealed that cloud top temperatures quickly cooled to -60º C and colder (red color enhancement).

GOES-15 10.7 µm IR images

An AWIPS image of the 1-km resolution MODIS 11.0 µm IR channel data (below) shortly before the report of strong surface winds indicated that this storm exhibited a subtle “enhanced-v” storm top signature, with a minimum IR brightness temperature of -80º C. There was also a cluster of numerous cloud-to-ground lightning strikes (primarily negative in charge) just east of the vertex of the enhanced-v signature.

MODIS 11.0 µm IR image + Cloud to ground lightning + Wind report

About a half hour before the report of the strong surface winds, the 1-km resolution AVHRR Cloud Top Temperature product indicated a minimum value of -80º C, with a maximum Cloud Top Height of 16 km (below).

POES AVHRR Cloud Top Temperature and Cloud Top Height products

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GOES-15 0.63 µm visible images

Unusually hot and dry mid-August conditions beneath a strong ridge of high pressure across British Columbia led to a major outbreak of wildfires across that western Canadian province — 1-km resolution GOES-15 0.63 µm visible channel images (above) showed the development of a number of large and very dense smoke plumes late in the day on 14 August 2010. A veil of smoke aloft from the previous day of fire activity could also be seen drifting southwestward across the adjacent offshore waters of the Pacific Ocean.

GOES-15 is currently providing imagery during its Post Launch Science Test; real-time GOES-15 imagery is available for viewing on the SSEC Geostationary Image Browser.

The corresponding 4-km resolution GOES-15 3.9 µm shortwave IR images (below) revealed numerous fire “hot spots” (black to red pixels) across the region. The hottest fire pixels exhibited IR brightness temperatures of 338 K. Note how the number and intensity of the fire hot spots diminished after sunset. The large arc of very hot IR brightness temperatures seen over the Pacific Ocean at the Earth’s edge was due to sun glint.

GOES-15 3.9 µm shortwave IR images

The comparison of a 1-km resolution NOAA-16 AVHRR Red/Green/Blue (RGB) image (created using AVHRR channels 1/2/4) with the corresponding AVHRR 3.7 µm shortwave IR image (below) revealed that a a few of the fire hot spots were easily detected even though they were beneath very thick smoke plumes.

AVHRR Red/Green/Blue (RGB) image + 3.7 µm shortwave IR image

A comparison of a 4-km resolution GOES-15 3.9 µm shortwave IR image with the corresponding 1-km resolution NOAA-16 3.7 µm shortwave IR image (below) demonstrated the value of higher spatial resolution for helping to more accurately identify the exact location of even the smaller active fire pixels; on one of the largest fires located near the center of the image, it can be more clearly determined that a ring of active fires was burning around a core of spent fuels. In addition, the northwestward “parallax shift” was evident due to the large viewing angle of the GOES-15 satellite (positioned at a longitude of 89.5º over the Equator).

GOES-15 3.9 µm + NOAA-16 AVHRR 3.7 µm shortwave IR images

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A weak, isolated tornado developed in southwestern Minnesota during the afternoon of 11 August 2010. GOES-15 imagery, above, shows the development of modest cumulus convection that spawned the tornado. The 5-minute time-step in the imagery is similar to that that will be available routinely from the ABI on GOES-R; the loop was taken as part of the GOES-15 science test as described here. (GOES-15 data are available at the SSEC Geostationary Satellite Image Browser) Although the tornadic event was a meteorological surprise (the convective outlook from the Storm Prediction Center, for example, did not foresee convection in the area), several satellite-based products diagnosed the instability that was present in the atmosphere. For example, the CIMSS NearCasting Tool (which tool uses the 3 water vapor channels on the GOES-13 Sounder to predict the 0-6 hours evolution of the theta-e destribution in the troposphere) showed a region of enhanced convective instability over southern Minnesota (see image below). In addition, GOES-13 Sounder estimates of Lifted Index (see the bottom two panels of the linked-to image) show southern Minnesota at the northern edge of unstable air.

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Recent news articles (such as this one) have noted the unusual warmth present in the surface waters of the Great Lakes. Clear skies over the western Great Lakes on Sunday 8 August allowed MODIS instruments to measure sea surface temperatures, and the warm temperatures are plain to see. These warm temperatures have persisted for some time, and 5-day plots for the Buoy in central Lake Michigan (buoy 45007), northern Lake Michigan (buoy 45002), and the center of Lake Superior (buoy 45001) all confirm the MODIS readings: unusual warmth in the Lakes. In fact, many of the lake surface temperature readings are near the top of the 4th quartile in the statistical distribution (see data here for buoy 45001 and here for buoy 45007).

Data from the AVHRR on board the NOAA series of satellites show similarly warm temperatures. Here is an afternoon image from NOAA-19 from 8 August.

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