GOES-13 Visible (0.63 µm) images, with hourly surface weather symbols [click to play animation]
A vigorous clipper-type shortwave moved rapidly southeastward across the Upper Midwest on 02 April 2016
; there were widespread convective elements associated with this system as seen in GOES-13 Visible (0.63 µm) images (above),
which produced moderate to heavy snowfall at times (and even thundersnow) creating brief white-out conditions (time-lapse
video from the AOSS rooftop camera in Madison, Wisconsin). A sequence of visible images from the polar-orbiting MODIS, VIIRS, and AVHRR instruments (below)
provided another detailed view of these convective elements. This disturbance produced strong winds
and accumulating snowfall
; more information can also be found here
from the NWS Chicago.
MODIS, VIIRS, and AVHRR visible images [click to enlarge]
A pronounced warm/dry signature of middle-tropospheric subsidence (yellow color enhancement)
was evident on GOES-13 Water Vapor (6.5 µm) images (below),
which appeared to be along or just ahead of the areas of stronger wind gusts at the surface.
GOES-13 Water Vapor (6.5 µm) images with hourly wind gusts in knots [click to play animation]
This area of middle-tropospheric subsidence was located along the leading edge of a strong (110-120 knot) 500 hPa jet, as indicated by the NAM40 model isotachs (below)
GOES-13 Water Vapor (6.5 µm) images with METAR surface reports, surface fronts, and NAM40 500 hPa wind isotachs [click to play animation]
The convective elements were relatively shallow, with cloud-top infrared brightness temperatures only in the -20 to -30º C range (cyan to darker blue color enhancement)
as seen in 4-km resolution GOES-13 Infrared Window (10.7 µm) images (below)
and also in 1-km resolution MODIS, VIIRS, and AVHRR infrared images
GOES-13 Infrared Window (10.7 µm) images, with hourly surface weather symbols [click to play animation]
The 24-hour snowfall amounts ending at 12 UTC on 02 and 03 April are shown below, from the NOHRSC
site. There was a narrow swath of snowfall in excess of 3 inches just north of the track of the surface low (surface analyses
), from northeast Minnesota across Wisconsin to southwest Lower Michigan.
24-hour snowfall amounts (in inches) ending at 12 UTC on 02 and 03 April [click to enlarge]