25th Anniversary of the Oakfield, Wisconsin F5 tornado

July 18th, 2021 |

An F5 tornado struck the village of Oakfield, Wisconsin late in the day on 18 July 1996 (NWS Milwaukee story). An animation of GOES-8 (GOES-East) Visible images (below) showed the development of supercell thunderstorms as they moved east-southeastward across the area. Oakfield is located just southwest of Fond du Lac (KFLD), and is denoted by the yellow ‘+’ symbol on the images. Overshooting tops were evident on these thunderstorms.

GOES-8 Visible images [click to play animation | MP4]

GOES-8 Visible images [click to play animation | MP4]

The corresponding GOES-8 Infrared Window images (below) revealed cloud-top infrared brightness temperatures as cold as -63.6ºC (darker shades of red) at 2345 UTC, which was approximately 30 minutes prior to the tornado moving through Oakfield (the GOES-8 imager instrument was actually scanning the Oakfield area at 2348 UTC).

GOES-8 Infrared images [click to play animation | MP4]

GOES-8 Infrared images [click to play animation | MP4]

On a larger-scale view of GOES-8 Water Vapor images (below), a sharp gradient of warm-to-cool brightness temperature — orange/yellow to blue enhancement, portraying the gradient of dry air to moist air — highlighted the presence of a middle-tropospheric jet streak that was moving southeastward across the state.

GOES-8 Water Vapor images [click to play animation | MP4]

GOES-8 Water Vapor images [click to play animation | MP4]

Examples of Derived Product Images from the GOES-8 Sounder can be seen here.

A View of the Development of Geostationary Imagers through the lens of BAMS

May 14th, 2020 |

A collection of 60 BAMS covers spanning the years, to highlight the rapid advance of imaging from the geostationary orbit, is shown above (a version that loops more slowly can be seen here). The first cover is the first of BAMS, in January of 1920, while the second, from January of 1957 is the first time artificial ‘satellite’ was in a title of a BAMS article. The third image, from November of 1957, is a remarkable article on potential uses of satellites. This included both qualitative uses: (1) Clouds, (2) Cloud Movements, (3) Drift of Atmospheric Pollutants, (4) State of the Surface of the Sea (or of Large Lakes), (5) Visibility or Atmospheric Transparency to Light — and quantitative uses: (1) Albedo, (2) Temperature  of  a  Level  at  or  Near  the Tropopause, (3) Total Moisture Content., (4) Total  Ozone  Content, (5) Surface  (Ground-Air Interface) Temperature, and (6) Snow Cover. Early covers showcase rockets, balloons and high-altitude aircraft to prepare the way to human space travel (Gemini, Apollo, etc.), polar-orbiters (TIROS, NIMBUS, VHRR, NOAA, etc.) and finally geostationary orbit (ATS-1, ATS-3, SMS, GOES, Meteosat, INSAT, Himawari, etc.).

Reasons to look back at the BAMS covers:

Interactive web page, with links to the original “front matter”.

Montage of select BAMS covers

Montage of select BAMS covers

Note: All cover images are from the Bulletin of the American Meteorological Society.

A look back at “Hurricane Huron” in 1996

September 14th, 2018 |

GOES-8 Visible (0.65 µm) images, with hourly surface wind barbs and gusts [click to play animation | MP4]

GOES-8 Visible (0.65 µm) images, with hourly surface wind barbs and gusts [click to play animation | MP4]

GOES-8 Visible (0.65 µm) images (above) showed the cloud features — including spiral banding and a cloud-free core resembling an eye — associated with a deepening area of low pressure over Lake Huron (surface analyses) on 14 September 1996. This storm acquired some characteristics of a tropical cyclone, being referred to in the literature as “Hurricane Huron“.

A look back at the Blizzard of 02-04 January 1999

January 1st, 2016 |

GOES-8 Water Vapor (6.5 µm) images [click to play MP4 animation]

GOES-8 Water Vapor (6.5 µm) images [click to play MP4 animation]

The evolution of the Blizzard of 02-04 January 1999 — which impacted large portions of the Midwest and Great Lakes regions of the US, as well as parts of eastern Canada — was captured by GOES-8 Water Vapor (6.5 µm, 8-km resolution) images (above; also available as a 61-Mbyte animated GIF). On 01 January, the water vapor image signature of a shortwave trough over New Mexico and Texas could be seen, which began to intensify and move northeastward; at the same time, the signature of another shortwave trough began moving southeastward across eastern Montana and the Dakotas. Energy from this northern shortwave appeared to phase with that of the southern shortwave late on 02 January into early on 03 January, helping the storm to further intensify.

GOES-8 Infrared (10.7 µm, 4-km resolution) images (below; also available as a 111-Mbyte animated GIF) showed that cloud-top IR brightness temperatures began to cool into the -50 to -60º C range (orange to red color enhancement) over large portions of the Upper Midwest and Great Lakes regions during the day on 02 January. As the bulk of the storm energy moved northeastward over Canada on 03-04 January, evidence of clouds associated with a TROugh of Warm air ALoft (TROWAL) persisted across parts of Minnesota and Wisconsin.

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

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

Even though some patches of clouds remained in the aftermath of the blizzard on 04 January, the extent of snow cover across much of the eastern US could be seen — from northern Arkansas to Minnesota, and from the Dakotas and Nebraska to Ohio — on GOES-8 Visible (0.65 µm, 1-km resolution) images (below; also available as a 15 Mbyte animated GIF). Bands of lake effect snow were also evident over each of the Great Lakes, as very cold arctic air flowed across the ice-free waters in the wake of the storm.

GOES-8 Visible (0.65 µm) images [click to play MP4 animation]

GOES-8 Visible (0.65 µm) images [click to play MP4 animation]

In the Upper Midwest region, storm total snowfall amounts included: 28.0 inches in South Haven, Michigan; 26.8 inches in Plymouth, Indiana; 23.0 inches in Dalton, Wisconsin; and 19.6 inches a Chicago O’Hare, Illinois. Chicago recorded 18.6 inches of snow on 02 January — their largest single-day snowfall on record. In Canada, Toronto, Ontario’s Pearson International Airport was closed by the storm, where 16.0 inches of snow fell. With deep snow cover and a cold post-storm arctic air mass in place, the all-time record low temperature for the state of Illinois (-36º F) was set at Congerville on 05 January.

Additional details on the January 1999 Blizzard can be found here and here.