Cold weather outbreak across the Upper Midwest and Great Lakes

January 30th, 2019 |

GOES-16 Air Mass RGB images, 28-30 January [click to play MP4 animation]

GOES-16 Air Mass RGB images, 28-30 January [click to play MP4 animation]

A highly-amplified upper air and jet stream pattern allowed a lobe of the polar vortex to migrate southward across southern Canada and the north-central US — leading to an outbreak of arctic air throughout the Upper Midwest and Great Lakes during the 29 January – 30 January 2019 period. The path and expansion of the cold arctic air was apparent in GOES-16 (GOES-East) Air Mass RGB images from the AOS site (above) — which first became evident over the Canadian arctic beginning on 28 January. The coldest air exhibited pale shades of yellow to beige in the Air Mass RGB images.

GOES-16 “Clean” Infrared Window (10.3 µm) images (below) also showed the southward expansion of arctic air into the north-central US — surface infrared brightness temperatures of -30 to -40ºC (darker blue to green enhancement) covered a large area. Such cold infrared brightness temperatures are normally associated with clouds in the middle to upper troposphere. Surface air temperatures of -20 to -40ºF were widespread, along with wind chill values of -40 to -70ºF, leading to numerous school and business closures. Two of the coldest official temperatures in the US on the morning of 30 January were -48ºF at Norris Camp, Minnesota and -44ºF at Bottineau, North Dakota (the high temperature in Bottineau on the previous day, 29 January, was only -26ºF); however, there were a few North Dakota Department of Transportation roadside sensors that reported low temperatures of -49ºF.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, 28-30 January [click to play MP4 animation]

GOES-16 True Color RGB images (below) revealed a variety of multiple-band and single-band lake effect snow features as the arctic air moved across the Great Lakes. In addition, elongated and long-lived cloud bands created snow squall conditions across parts of Ohio and Pennsylvania.

GOES-16 True Color images [click to play MP4 animation]

GOES-16 True Color images [click to play MP4 animation]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 (at 1802 UTC) and Suomi NPP (at 1852 UTC) viewed using RealEarth (below) provided a closer look at the cloud bands across Ohio and Pennsylvania.

True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 (at 1802 UTC) and Suomi NPP (at 1852 UTC) [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 (at 1802 UTC) and Suomi NPP (at 1852 UTC) [click to enlarge]


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GOES-16 Clear-sky Total Precipitable Water, 1202 UTC on 30 January 2019 (Click to enlarge)

In addition to being extremely cold, the airmass over the Upper Midwest was extremely dry. The image above shows the Baseline GOES-R Total Precipitable Water product. The default AWIPS color enhancement has been modified to better capture the extreme dryness. Regions in light blue over western Minnesota and the eastern Dakotas curving through Iowa into northern Illinois show TPW values around 0.01″ ; green shadings over Wisconsin and eastern Minnesota correspond to values closer to 0.03″. In such dry airmasses, it is possible to see surface features in the infrared 7.3 low-level ABI Water Vapor Channel, Band 10, and the morning of 30 January was no exception, below. Surface features like rivers are notable in Illinois, for example. Even the heat island of the Minneapolis/St. Paul is apparent (albeit barely).  Surface features over northern Minnesota and Wisconsin aren’t quite so apparent, perhaps because of the increased amounts of moisture there.  There is likely less surface temperature contrast there, also, as rivers/lakes are more likely frozen.  It is the temperature contrast — as best exemplified by the Great Lakes shorelines — that allows features to appear in the Water Vapor imagery.

GOES-16 Low-Level Water Vapor Infrared (7.3 µm) Imagery, 1202 UTC on 30 January 2019 (Click to enlarge)

Weighting Functions (in real time, from this site) allow for an estimate of where information in different water vapor channels will be detected by the satellite. In the 0000 UTC 30 January 2019 example, below, from Chanhassen, MN (when total precipitable water there was 0.01″), a large signal is apparent from the low-level water vapor channel (7.3 µm); in fact, most of the information detected by the satellite was coming from the surface!  Even the mid-level water vapor (6.9 µm) had a component from the surface.  Weighting Functions for Davenport Iowa (The axis of the driest air shifted from near Chanhassen at 0000 UTC to near Davenport at 1200 UTC) at 0000 UTC and 1200 UTC are shown here; Note in the toggle that the level from which information is received by the satellite drops from 0000 to 1200 UTC as dry air moves in.

Clear-sky Weighting Function from Chanhassen MN, 0000 UTC on 30 January 2019 (Click to enlarge)

The GOES-16 Baseline Land Surface Temperature product, below, from 1200 UTC, shows many values at/below -45 F (purple shading) over Minnesota.  Dark blue values are around -25 F.  Note the relatively warm region over western Iowa, in cyan.  That part of Iowa lacks snowcover and exceptional cold rarely happens over bare ground.

GOES-16 Baseline Land Surface Temperature, 1202 UTC on 30 January 2019 (Click to enlarge)

===== 31 January Update =====

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with and without plots of hourly surface observations [click to play animation | MP4]

Across much of the Upper Midwest, the coldest temperatures occurred on the morning of 31 January. GOES-16 Infrared images (above) showed much of northeastern Minnesota and far northwestern Wisconsin — the low temperature of -56ºF at Cotton was only 4 degrees warmer than the all-time record low for Minnesota, and the low temperature of -47ºF at Butternut was 8 degrees warmer than the all-time record  low for Wisconsin (both of those records were set in early February 1996). The -56ºF in Cotton was not only the coldest temperature in the Lower 48 states on 31 January, but was also significantly colder than any official reporting station in Alaska that day. Also of interest in northeastern Minnesota, note the warmer plumes (darker blue enhancement; brighter greens are coldest) coming from power plants and industrial sites in the Iron Range area.

Farther to the south, GOES-16 Infrared images covering the Minnesota/Wisconsin/Iowa/Illinois region (below) also showed widespread cold surface brightness temperatures (shades of green). All-time record low temperatures were set at Cedar Rapids in Iowa (-30ºF) and at Moline (-33ºF) and Rockford (-31ºF) in Illinois. The cooperative observer at Mt. Carroll in northwestern Illinois reported a low of -38ºF — which, if verified, will establish a new all-time record minimum temperature for the state of Illinois.

GOES-16 "Clean" Infrared Window (10.3 µm) images, with plots of hourly surface observations [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.3 µm) images, with plots of hourly surface observations [click to play animation | MP4]

The recent stretch of days with cold air in place had helped the ice coverage to increase significantly in western Lake Superior — and the transition from northerly/northwesterly cold air advection to southwesterly warm air advection at the surface began to fracture a lot of this newly-formed lake ice (below).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with plots of hourly surface reports [click to play animation | MP4]

Ice coverage had also increased across much of western/central Lake Erie, although areas of open water continued to supply latent heat to help generate lake effect snow bands (below).

GOES-16 "Red" Visible (0.64 µm) images, with plots of hourly surface reports [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) images, with plots of hourly surface reports [click to play animation | MP4]

A sequence of Terra MODIS True Color RGB images (below) showed substantial growth of nearshore ice in the southern end of Lake Michigan from 29 to 31 January.

Terra MODIS True Color RGB images [click to enlarge]

Terra MODIS True Color RGB images [click to enlarge]

.A summary of this cold outbreak was compiled by NWS Duluth, NWS La Crosse, NWS Twin Cities and NWS Grand Forks.

Blowing snow across the Upper Midwest

January 24th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Near-Infrared (1.61 µm) images (above) displayed a long plume of horizontal convective roll (HCR) clouds across parts of the Upper Midwest on 24 January 2019. These HCR cloud features formed in the presence of strong northerly/northwesterly boundary layer winds in the wake of a cold frontal passage (surface analyses), and often highlight areas where significant blowing snow and ground blizzard conditions are likely occurring.

Animations of GOES-16 Visible and Snow/Ice images with plots of surface winds and weather type are shown below. ASOS sites report Haze (“H”) when the surface visibility — in this case, reduced by blowing snow — is less than 7 miles but greater than or equal to 4 miles. Some sites in Minnesota and Iowa reported a visibility between 0.5 and 2.0 miles at times (animation).

GOES-16 "Red" Visible (0.64 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

GOES-16 Near-Infrared "Snow/Ice" (1.61 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

The signature of the HCR clouds on GOES-16 Day Cloud Phase Distinction Red-Green-Blue (RGB) images from the AOS site (below) was one that more closely resembled ice crystal clouds (light pink hues) than supercooled water droplet clouds (brighter shades of white) — suggesting a high concentration of blowing snow lofted within the boundary layer by the HRC circulations. Snow cover appears as shades of green in the RGB images.

GOES-16 Day Cloud Phase Distinction RGB images [click to play animation | MP4]

GOES-16 Day Cloud Phase Distinction RGB images [click to play animation | MP4]

Ice accrual from freezing rain/drizzle in the Northeast US

January 22nd, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to play animation | MP4]

A large central/eastern US winter storm impacted much of the Northeast with rain, snow, freezing rain/drizzle and strong winds on 20 January 2019 (surface analyses) — and a post-storm comparison of GOES-16 (GOES-East)  “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images on 22 January (above) revealed a dark 1.61 µm signature (often indicative of significant ice accrual) in parts of New York, New Jersey, Connecticut, Rhode Island and Massachusetts. Since snow and ice are effective absorbers of radiation at the 1.61 µm wavelength — with ice absorbing even more strongly — those features appear as darker shades of gray in the Snow/Ice imagery.

A closer view using NOAA-20 VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images at 1708 UTC is shown below (note: the NOAA-20 VIIRS image is incorrectly labeled as Suomi NPP). Ice accrued in thicknesses up to 0.60 inch at Meridan in central Connecticut and 0.40 inch at Newburgh in far eastern New York.

NOAA-20 VIIRS Visible (0.64 µm) and Near-Infrared "Snow/Ice" (1.61 µm) images [click to enlarge]

NOAA-20 VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to enlarge]

Blowing snow in southern Manitoba and the Red River Valley

January 15th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Near-Infrared “Snow/Ice (1.61 µm, right) images, with hourly plots of surface wind and weather type [click to play animation | MP4]

A comparison of GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above) revealed plumes of blowing snow originating over northern Lake Winnipeg and southern Lake Manitoba, lofted by strong northerly winds in the wake of a cold frontal passage. The blowing snow originating over the southern portion of Lake Manitoba was then then channeled southward into the Red River Valley (topography), with horizontal convective roll clouds eventually developing.

In a sequence of MODIS Visible (0.65 µm) and Snow/Ice (1.61 µm) images from Terra and Aqua in addition to VIIRS Visible (0.64 µm) and Snow/Ice (1.61 µm) from NOAA-20 and Suomi NPP (below), the plumes of blowing snow were also easier to detect in the Snow/Ice images (due to better contrast against the existing snow cover).

MODIS Visible (0.65 µm) and Snow/Ice (1.61 µm) images from Terra and Aqua plus VIIRS Visible (0.64 µm) and Snow/Ice (1.61 µm) from NOAA-20 and Suomi NPP [click to enlarge]

MODIS Visible (0.65 µm) and Snow/Ice (1.61 µm) images from Terra and Aqua plus VIIRS Visible (0.64 µm) and Snow/Ice (1.61 µm) from NOAA-20 and Suomi NPP [click to enlarge]

A closer view of the Lake Manitoba plume is shown below; surface observations indicated that visibility was reduced to 1/4 statute mile at locations such as Calilier ND (plot | text) and Hallock MN (plot | text).

NOAA-20 and Suomi NPP VIIRS Snow/Ice (1.61 µm) images, with plots of surface observations [click to enlarge]

NOAA-20 and Suomi NPP VIIRS Snow/Ice (1.61 µm) images, with plots of surface observations [click to enlarge]

An Aqua MODIS True Color Red-Green-Blue (RGB) image centered on Winnipeg, Manitoba (source)  is shown below.

Aqua MODIS True Color image [click to enlarge]

Aqua MODIS True Color image [click to enlarge]

Toggles between 250-meter resolution Terra/Aqua MODIS True Color and False Color RGB images (centered between Lake Manitoba and the North Dakota border) from the MODIS Today site (below) provided a more detailed view of the blowing snow streaming southeastward from Lake Manitoba into far northeastern North Dakota and far northwestern Minnesota.

Terra MODIS True Color and False Color RGB images [click to enlarge]

Terra MODIS True Color and False Color RGB images [click to enlarge]

Aqua MODIS True Color and False Color RGB images [click to enlarge]

Aqua MODIS True Color and False Color RGB images [click to enlarge]