The Storm Prediction Center has revised its criteria for initiating GOES Rapid Scan Operations (RSO) calls. Previously, RSO was automatically activated when a Moderate Risk (MDT) appeared in the SPC Day 1 Convective Outlook. On October 1st that was changed per a September email from SPC:

Starting October 1, the SPC Lead Forecaster will contact the NCO/SDM to request GOES RSO whenever a Day 1 Convective Outlook includes an ENH Risk area. Data from the first six months of 2015 suggests SPC would request RSO on approximately 10-20 more days compared to the current MDT Risk criterion. Activating RSO on a more frequent basis using the ENH Risk criterion would improve NWS forecaster situational awareness on convectively active days and help prepare users for much higher temporal frequency GOES-R data.

An Enhanced Risk was issued on 11 November 2015 as a strong extratropical cyclone was developing over the midsection of the country. The image above shows the GOES-13 Water vapor imagery from 1145 UTC on 11 November. A strong jet extends from the southwestern United States northeastward. On the previous day (10 November, at 12 UTC) Albuquerque reported 135-knot winds at 300 hPa (and no winds at all at 200 hPa as the balloon was lost to the tracker); at 00 UTC on 11 November, winds were 162 knots just above the 250 hPa level. Strong veering, indicating warm advection, is apparent over the mid-Mississippi River Valley. Low-level warm advection is forecast to increase as the extratropical cyclone intensifies.

Update: GOES-East began RSO at 1545 UTC on 11 November 2015 — a few image animations are shown below.

Of particular interest on 6.5 µm water vapor imagery, above, was the tightly-wrapped signature of the middle-tropospheric vorticity center moving northeastward along the Kansas/Nebraska border.

The 10.7 µm Infrared images, above, showed the development of thunderstorms across Iowa which exhibited cloud-top IR brightness temperatures in the -50 to -60º C range (yellow to red color enhancement). Hail, damaging winds, and tornadoes were produced by these areas of deep convection (SPC storm reports).

3.9 µm Shortwave Infrared images, above, displayed numerous “hot spots” (black to yellow to red color enhancement) due to fire activity in parts of northeastern Oklahoma and southeastern Kansas.

Finally, 0.63 µm Visible channel images, above, showed the hazy signature of smoke plumes from these Kansas/Oklahoma fires (along with a separate plume of blowing dust). In addition, as clouds cleared along the western edge of the storm, swaths of fresh snow cover could be seen over portions of Wyoming, Colorado, South Dakota, Nebraska, and Kansas. As much as 12.5 inches of snow was reported in northeastern Colorado, with wind gusts of 75 mph creating blizzard conditions.

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Today marks the 40-year anniversary of the powerful Great Lakes storm that was responsible for the sinking of the SS Edmund Fitzgerald (which occurred on 10 November 1975). The image composites (above, courtesy of Jean Phillips, Schwerdtfeger Library) were constructed from daytime and nighttime overpasses of the NOAA-4 polar-orbiting satellite, and show the large cloud shield of the storm moving northeastward from the Great Lakes into eastern Canada during the 10-11 November 1975 period. The rapidly-intensifying nature of the storm can seen by comparing the 12 UTC surface analyses on 09 November and 10 November.

Since the first operational geostationary weather satellites (SMS-1 and SMS-2) were relatively new back in 1975, the CIMSS Regional Assimilation System (CRAS) model was utilized to generate synthetic Infrared (IR) satellite images to provide a general idea of what the satellite imagery might have looked like for this intense storm. The 48-hour sequence of synthetic CRAS IR images (below) shows the evolution of the model-derived cloud features at 1-hour intervals.

Additional information about this Edmond Fitzgerald storm can be seen on this website, as well as the NWS Marquette and this journal article.

A strong storm of similar character developed over the Upper Midwest and Great Lakes region on 9-11 November 1998. GOES-8 (GOES-East) Infrared (10.7 µm) and Water Vapor (6.7 µm) images of this 1998 storm are shown below (and are also available as YouTube videos). This storm set all-time minimum barometric pressure records for the state of Minnesota, with 962 mb (28.43″) recorded at Albert Lea and Austin in southern Minnesota. On the cold side of the storm, up to 12.5 inches of snow fell at Sioux Falls in southeastern South Dakota. Wind gusts were as high as 64 mph in Minnesota and 94 mph in Wisconsin.

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GOES-13 Visible Imagery, above, shows Tropical Storm Kate northeast of the Bahamas late in the day on 9 November. The storm is over a region of warm sea surface temperatures, below (imagery from the CIMSS Tropical Weather Site), in an environment of low shear. RapidScat winds show winds between 35 and 40 knots to the northeast of the storm center. The projected path is also shown, paralleling the East Coast before moving out to sea. The path takes the storm north of Bermuda as well.

Suomi NPP viewed the storm as well, shortly after noon on 9 November. The Visible (0.64 µm), near-infrared (1.61 µm) and 11.35 µm imagery are shown below. The 1.61 imagery shows darker returns over ice clouds because of absorption at that wavelength. The extensive cirrus shield over Kate’s convection (and along the East Coast is association with frontal system) is readily apparent. Water-based clouds, in contrast, are bright white in both the visible and near-infrared channels.

ASCAT winds from 0230 UTC on 10 November (below) also show strongest winds on the northern and eastern sides of the storm.

Kate was upgraded to a minimal Hurricane at 0900 UTC on 11 November.

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The Mount Rinjani volcano in Indonesia began a period of eruptions on 25 October 2015; the ash plume became very apparent on Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images from RealEarth on 03 and 04 October (above). The volcanic ash disrupted flights at Denpasar Airport in Bali (the red dot at the southern tip of the island) for several days.

A GOES-R volcanic ash height product (derived using Himawari-8 AHI data) from the SSEC Volcanic Cloud Monitoring site indicated that the plume reached heights of 10 km (dark blue color enhancement) at times during the 03-04 October period (below).

McIDAS-V images of Suomi NPP VIIRS Day/Night Band (0.7 µm), near-IR (1.6 µm), shortwave IR (3.74 µm), and IR (11.45 µm) images (below, courtesy of William Straka, SSEC) showed the hot spot and nighttime glow of the summit of the Rinjani volcano at 1733 UTC on 04 November.

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