ZCZC SPCSWOMCD ALL
ACUS11 KWNS 010708 
SPC MCD 010708 
ILZ000-MOZ000-011215-

Mesoscale Discussion 0005
NWS Storm Prediction Center Norman OK
0108 AM CST Fri Jan 01 2021

Areas affected...Portions of far east Missouri into central Illinois

Concerning...Freezing rain 

Valid 010708Z - 011215Z

SUMMARY...Freezing rain potential is increasing across portions of
far eastern Missouri into central Illinois. A couple areas may
briefly see up to .06 in/3 hr rates in the heavier rain bands.

DISCUSSION...Widespread warm-air/moisture advection is underway
across portions of the Middle Mississippi Valley in advance of a
gradually approaching surface and upper low currently positioned
across the southern Plains. Widespread heavier precipitation is also
approaching portions of eastern Missouri into central Illinois,
where a dry 850-700 mb layer continues to moisten. METAR
observations depict sub-freezing surface temperatures, and given the
aforementioned dry air aloft, wet-bulb surface temperatures have
been able to sustain well below 32F for several hours. Multiple ASOS
sites across far eastern MO show that ice accumulations have already
begun. 

The 850-700 mb dry layer is expected to sufficiently moisten in the
next couple of hours to support higher freezing rain rates, which
may briefly approach .06 in/3 hrs in some of the stronger rain
bands, especially in the 08-12Z period, as suggested by 00Z HREF
guidance and the last few runs of the HRRR.

..Squitieri/Edwards.. 01/01/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PAH...LOT...ILX...LSX...DVN...

LAT...LON   38098835 37808891 37798961 37909004 38199045 38639076
            39479095 39959084 40199072 40529000 40638907 40228781
            39798773 39238766 38868769 38468794 38098835 

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