Synthetic satellite imagery « CIMSS Satellite Blog

40th Anniversary of the “Edmund Fitzgerald Storm”

November 10th, 2015 | Scott Bachmeier

NOAA-4 daytime and nighttime Infrared composites [click to enlarge]

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.

CRAS model simulated Infrared imagery [click to enlarge]

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.

GOES-8 Infrared (10.7 µm) images [click to play MP4 animation]

GOES-8 Water Vapor (6.7 µm) images [click to play MP4 animation]

Posted in GOES-8, Historical, POES, Synthetic satellite imagery, YouTube | No Comments »

Flash Floods in Hawaii

May 10th, 2011 | Scott Lindstrom

MIMIC TPW over the eastern Pacific Ocean

Images of MIMIC Total Precipitable Water, above, show moist air emerging from the Intertropical Convergence Zone and streaming north over the western islands of Hawaii.

GOES Imager Water Vapor imagery

GOES-West water vapor imagery (the rocking animation, above) shows the circulation north of the Hawaiian islands that is drawing moisture northward. Because the water vapor channel on the Imager is most accurate at sensing the temperature at the top of the moist layer, however, water vapor imagery can significantly underestimate the amount of water vapor that is in the atmospheric column. The warm temperatures evident over the western Hawaiian Islands (the blue and yellow enhancements) suggest that the water vapor that is emitting radiation sensed by the satellite is warm and confined to lower levels in the atmosphere. Images of Total Precipitable Water give a better indication of how much water vapor is available for precipitation.

Flash flood watches continue through late Tuesday, 10 May, for the western Islands of Hawaii (Oahu, Kauai and Niihau) as the moisture plume continues to drift westward.

The CIMSS MIMIC Total Precipitable Water product is also available for NWS forecast offices to add to their local AWIPS workstations (via Unidata LDM subscription) — a sample animation is shown below. To learn more about the MIMIC TPW product and its applications, a VISIT lesson is also available.

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

Posted in General interpretation, GOES-11, Heavy rain / flooding, Synthetic satellite imagery | No Comments »

Possible development of a subtropical or a tropical disturbance in the Atlantic Ocean?

April 20th, 2011 | Scott Bachmeier

MIMIC Total Precipitable Water (TPW) product

The National Hurricane Center initiated Invest 91 to monitor the potential development of a subtropical or even possibly a tropical cyclone over the western Atlantic Ocean on 20 April 2011. AWIPS images of the MIMIC Total Precipitable Water (TPW) product (above; click image to play animation) showed that a tongue of moisture was being advected northward from the band of higher moisture along the Inter-Tropical Convergence Zone (ITCZ) — and this moisture plume was being wrapped into the circulation of the developing disturbance.

A closer look at the MIMIC TPW product at 14:00 UTC along with an overlay of ASCAT scatterometer winds (below) revealed a well-defined cyclonic circulation at the surface, with gale force winds within the northwest quadrant of the storm.

MIMIC TPW product + ASCAT surface winds + Surface analysis

===== 22 APRIL UPDATE =====

GOES-13 0.63 Âµm visible channel images

Animations of GOES-13 0.63 Âµm visible channel images (above) and GOES-13 10.7 Âµm IR channel images (below) from the CIMSS Tropical Cyclones site continued to show very well-defined cyclonic circulations associated with the feature on 22 April 2011.

GOES-13 10.7 Âµm IR images

GOES-13 6.5 Âµm water vapor channel images (below) indicated that dry mid-tropospheric air was wrapping into the system from the south and east.

GOES-13 6.5 Âµm water vapor channel images

A comparison of AWIPS images of the POES AVHRR 0.86 Âµm visible channel with ASCAT scatterometer surface wind data (below) revealed the development of deep convective elements just to the north of the low-level circulation center.

POES AVHRR 0.86 Âµm visible image + ASCAT scatterometer surface winds

A sequence of three POES AVHRR 0.86 Âµm visible channel images (below) showed the evolution of the convective elements associated with the disturbance during the day.

POES AVHRR 0.66 Âµm visible channel images

Posted in AVHRR, GOES-13, Marine weather, Satellite winds, Severe convection, Synthetic satellite imagery, Tropical cyclones | No Comments »

35-year anniversary of the sinking of the Edmund Fitzgerald

November 10th, 2010 | Scott Bachmeier

48-hour simulated IR satellite imagery from the CRAS model (9-11 Nov 1975)

Today marks the 35-year anniversary of the powerful Great Lakes storm that was responsible for the sinking of the SS Edmund Fitzgerald (on 10 November 1975). 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 IR satellite images to provide an idea of what the satellite imagery might have looked like for this intense storm (CRAS model surface winds). A 48-hour sequence of synthetic IR images (above) shows the evolution of the model-derived cloud features at 1-hour intervals.

As part of the CIMSS involvement in GOES-R Proving Ground activities, CRAS synthetic forecast satellite imagery (IR and Water Vapor channels, below) is currently being made available in an AWIPS format for interested NWS forecast offices to add to their local AWIPS workstations (via LDM subscription). For more information, see the CRAS Imagery in D-2D site. VISIT training is also available on the topic.