MD 2062 CONCERNING SNOW SQUALL FOR EASTERN MISSOURI TO WESTERN ILLINOIS
Mesoscale Discussion 2062
NWS Storm Prediction Center Norman OK
1059 AM CST Thu Dec 22 2022
Areas affected...Eastern Missouri to western Illinois
Concerning...Snow Squall
Valid 221659Z - 222100Z
SUMMARY...Sporadic, short-lived blizzard/snow squall conditions will
be possible under a mesoscale snow band as it tracks east across
parts of eastern Missouri and western Illinois through early/mid
afternoon.
DISCUSSION...Recent surface observations from far eastern IA show
visibility reductions down to 1/4 mile at times under a persistent,
though loosely organized, snow band. Based on latest RAP
mesoanalysis, this band is primarily being driven by broad scale
ascent ahead of a deepening upper low over the central Plains,
augmented by more focused frontogenetical lift within the 850-700 mb
layer. Forecast soundings indicate that much of this lift coincides
with a 100-150 mb deep dendritic growth zone, which is likely
yielding moderate, to at times heavy, snowfall rates up to 1
inch/hour. Concurrently, strong cold advection behind the surface
front is supporting frequent wind gusts between 25-35 knots from
eastern IA to central MO. The combination of these winds and
moderate snowfall rates will likely result in periods of
blizzard/snow squall conditions with visibility reductions briefly
falling to 1/4 mile under the snow band as it continues moving east
through early/mid afternoon.
..Moore.. 12/22/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...ILX...LSX...DVN...SGF...EAX...
LAT...LON 39969175 41699077 42249007 42128917 41658861 40958810
40208837 38978904 38298989 37559125 37559200 38439313
38789294 39259244 39969175
