Radar reflectivity mosaic

A radar reflectivity composite (above) showed a large Mesoscale Convective System (MCS) that was moving across parts of Minnesota and Wisconsin on 14 June 2012, producing heavy rainfall (2.99 inches at Zumbrota in southeastern Minnesota) and some hail (SPC storm reports).

AWIPS images of GOES-13 0.63 µm visible channel data (below; click image to play animation) showed a broad area of anticyclonic cirrus outflow around the southern periphery of the MCS as it was dissipating during the late morning and early afternoon hours. There were a number of pilot reports of moderate turbulence seen within this banded area of cirrus outflow.

GOES-13 0.63 µm visible images with pilot reports of turbulence (click image to play animation)

The banding structure within the cirrus outflow region was clearly shown on a 375-meter resolution (re-mapped onto an AWIPS 1 km grid) Suomi NPP VIIRS 11.45 µm IR image at 18:35 UTC  (below). A comparison with the corresponding 4-km resolution GOES-13 10.7 µm IR image demonstrated the advantage of higher spatial resolution for depicting such features.

Suomi NPP VIIRS 11.45 µm IR image + GOES-13 10.7 µm IR image

The pronounced anticyclonic motion of the cirrus outflow (also verfied using MADIS 1-hour cloud-tracked winds) was creating strong wind shear aloft over much of eastern Iowa, southern Wisconsin, and northern Illinois — note how different the satellite wind vector directions were from the NAM 500-100 hPa deep-layer wind flow streamlines over that region (below). This strong wind shear aloft may have been a factor contributing to the numerous pilot reports of moderate turbulence within the area of cirrus outflow.

VIIRS 11.45 µm IR image + MADIS cloud-tracked wind vectors + NAM deep layer mean wind

A similar depiction of the pronounced wind shear aloft was seen a few hours earlier on a 16:40 UTC MODIS 11.0 µm IR image (below).

MODIS 11.0 µm IR image + MADIS cloud-tracked wind vectors + NAM deep layer mean wind

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Suomi NPP VIIRS 0.64 µm visible and 1.61 µm near-IR images

AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and 1.61 µm near-IR channel data (above) showed that there was a wide ice-free passage leading from the Bering Sea northward and northeastward through the Chukchi Sea toward Barrow, Alaska (station identifier PABR) on 14 June 2012. On the visible image, ice and optically thick clouds were brighter white, while on the near-IR image ice and water looked very dark (with supercooled water droplet clouds taking on a brighter appearance). Additional information on ice break-up at Barrow is available from the Sea Ice Group at the University of Alaska Fairbanks.

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MODIS and AVHRR Lake Surface Temperatures (click image to play animation)

Clear skies over the upper Midwest on the morning of 13 June 2012 allowed the MODIS instrument on board Aqua and the AVHRR instrument on board NOAA-19 to sense the surface temperature of Lakes Michigan and Superior. Which instrument yielded observations that were closer to those recorded in situ by the moored buoys maintained by the National Data Buoy Center? The loop above of MODIS Lake Surface Temperatures and AVHRR Lake Surface Temperatures suggests that the MODIS-derived values are 1-3 Fahrenheit degrees warmer. MODIS values are also closer to the observed values at the moored buoys (45002 and 45007 in Lake Michigan, 45003 in Lake Huron and 45004 in Lake Superior). The higher spectral resolution on MODIS leads to a more accurate depiction of the lake surface in this case.

The National Weather Service in Sullivan, WI, has noted that lake temperatures are running much warmer than normal this year, in part because of the record warmth in March.

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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 development of a very broad and dense smoke plume emanating from a large wildfire that was burning just northwest of Goose Bay, Labrador (station identifier CYYR)  in far eastern Canada on 13 June 2012. Note the appearance of a number of bright “pyro-cumulus” clouds near the fire source region, as the very hot fires produced intense updrafts to form large towering cumulus clouds. As an aside, it is interesting to note that there were still a number of large ice floes (slow-moving brighter white features) not far off the Labrador coast, which were drifting slowly northward during the day.

McIDAS images of 375-meter resolution (projected onto a 1-km AWIPS grid) Suomi NPP VIIRS 0.64 µm visible channel data and 3.74 µm shortwave IR channel data (below) showed the large size of the fire “hot spot” (yellow to red to black pixels), in addition to the thick smoke plume.

Suomi NPP VIIRS 0.64 µm visible channel and 3.74 µm shortwave IR channel images

A comparison of Suomi NPP VIIRS 3.74 µm shortwave IR images from 12 June and 13 June (below) show how large the fire hot spot had grown in a day. Note that the surface air temperature at Goose Bay plotted on the 12 June image was 93 F (33.9 C) — the high temperature at Goose Bay on that day was actually 95 F (35 C), only 2.2 F (1.2 C) shy of their all-time record high temperature for the month of June.

Suomi NPP VIIRS 3.74 µm shortwave IR images (12 June and 13 June)

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