GOES-15 6.5 µm water vapor channel images (click image to play animation)

McIDAS images of 4-km resolution GOES-15 6.5 µm water vapor channel data (above; click image to play animation) displayed the development of a classic “dry swirl” water vapor signature indicating the transition to an occluded cyclone during the 01 April – 02 April 2012 time period. The Ocean Prediction Center was forecasting large areas of hurricane force winds associated with this storm (00 UTC | 06 UTC | 12 UTC).

A sequence of AWIPS images of 1-km resolution MODIS 11.0 µm and POES AVHRR 12.0 µm IR channel data (below) showed a variery of small-scale banding structures during various stages of development of the storm.

MODIS 11.0 µm + POES AVHRR 12.0 µm IR channel images

The approach of a strong Potential Vorticity (PV) anomaly helped the storm to intensify rapidly, with with CRAS model fields indicating the tropopause (taken to be the pressure level of the PV1.5 surface) lowering to around the 900 millibar level by 06 UTC on 02 April (below).

Although the storm was near the edge of the GOES-15 sounder scan, an image of the GOES-15 sounder Total Column Ozone product (below) showed that the PV anomaly was situated along a strong ozone gradient (which is often the case).

GOES-15 6.5 µm water vapor image + GOES-15 sounder Total Column Ozone product (with overlays of CRAS model PV1.5 pressure)

The MIMIC Total Precipitable Water (TPW) product (below) showed the storm tapped an area of moisture that was situated north of the Hawaiian Islands, eventually stretching this moisture into a thin filament along the storm’s cold frontal boundary.

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

Later in the day, an overpass of a EUMETSAT MetOp satellite provided ASCAT ocean surface winds over the large occluded storm as it was moving slowly off the coast of British Columbia, Canada. A comparison of 1-km resolution MODIS 0.65 µm visible channel and MODIS 11.0 µm IR channel images with an overlay of ASCAT wind vectors is shown below.

MODIS 0.65 µm visible channel and 11.0 µm IR channel images + MetOp ASCAT scatterometer surface winds

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

McIDAS images of GOES-13 0.63 µm visible channel data (above; click image to play animation) revealed the cyclonic circulation of a Mesoscale Convective  Vortex (MCV) that was moving northeastward across Mississippi on 30 March 2012. This MCV appeared to play a role in helping to initiate new convective cells ahead of it as the atmosphere destabilized during the late morning and early afternoon hours.

AWIPS images of GOES-13 10.7 µm IR channel images (below; click image to play animation) helped to identify the apparent origin of the MCV — a large mesoscale convective system that developed along the Texas coast after about 15 UTC on the previous day (29 March).

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

A closer look at the parent mesoscale convective system using a 1-km resolution MODIS 11.0 µm IR image with overlays of cloud-to-ground lightning strikes (below) showed that the storm was producing a large number of lightning strikes. The coldest MODIS cloud top IR brightness temperatures were -70 C (darker black color enhancement).

MODIS 11.0 µm IR channel image + Cloud-to-ground lightning strikes

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GOES-15 + GOES-13 0.63 µm visible channel images

The “Lower North Fork Fire” near Aspen Park, Colorado began during the afternoon hours on 26 March 2012 and rapidly expanded to over 4100 acres in size. 2 fatalities resulted from this fire, with over 900 homes being evacuated and at least 27 homes damaged or destroyed. The combination of strong southwesterly winds (gusting in the 35-50 mph range) and very dry air (relative humidity values around 10%) created an environment that was favorable for rapid wildfire growth. A comparison of McIDAS images of GOES-15 (GOES-West) and GOES-13 (GOES-East) 0.63 µm visible channel data (above) showed the development of a large smoke plume with embedded pyrocumulus clouds.

The corresponding series of GOES-15 and GOES-13 3.9 µm shortwave IR images (below) revealed how quickly the fire “hot spot” (black to yellow to red color enhancement) grew in size.

GOES-15 + GOES-13 3.9 µm shortwave IR images

An AWIPS comparison of a 1-km resolution POES AVHRR 3.7 µm shortwave IR image with the corresponding 4-km resolution GOES-13 3.9 µm shortwave IR image just after 02 UTC or 8 pm local time  (below) demonstrated the advantage of higher spatial resolution for more accurately identifying the location and areal coverage of the fire.

POES AVHRR 3.7 µm + GOES-13 3.9 µm shortwave IR images

A larger scale HD-format view of GOES-13 0.63 µm visible channel images (below; click image to play animation) revealed other interesting features across the region, such as (1) a large blowing dust plume oriented from southwest to northeast across Colorado, (2) a terrain-induced standing wave cloud over southwestern Colorado, (3) the development of a line of thunderstorms across eastern Wyoming, and (4) another smaller blowing dust plume across eastern Idaho. Animated GIF courtesy of Tim Schmit, NOAA/ASPB/CIMSS.

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

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Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image

After the Suomi NPP satellite had experienced an anomaly and gone into a sun-pointing “safe mode” on 24 March, all the satellite instruments began to successfully recover by 26 March 2012. Shown above is a 750-meter resolution true-color Red/Green/Blue (RGB) image from the VIIRS instrument, acquired via the Direct Broadcast ground station at the Space Science and Engineering Center at the University of Wisconsin – Madison (image courtesy of Liam Gumley, SSEC). A number of interesting features can be seen in the image, including (1) the break-up of ice in Hudson Bay and James Bay in Canada, (2) smoke plumes from fires burning across parts of the southeastern US, and (3) the outflow of sediment-rich water from the mouth of the Mississippi River (and other rivers) into the Gulf of Mexico.

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