Mesoscale Discussion 0002
NWS Storm Prediction Center Norman OK
0844 PM CST Thu Dec 31 2020
Areas affected...Portions of northeast Oklahoma...southeast
Kansas...southwest into central Missouri
Valid 010244Z - 010845Z
SUMMARY...Freezing rain potential is expected to increase over the
next several hours across portions of northeast OK into central MO.
DISCUSSION...Precipitation has remained relatively light thus far
across portions of far northeast OK into central MO given the
presence of a dry 850-700 mb layer (per 00Z SGF observed sounding).
However, this dry layer, along with freezing/near-freezing surface
temperatures will encourage evaporative cooling with the onset of
heavier precipitation advecting from the south, making freezing at
the surface more likely. A few METAR observations have indicated
that light ice accumulations are already occurring along the MO/AR
border, as wet bulb surface temperatures have already begun to drop
below freezing in several locales. Low-level moisture/warm-air
advection and associated heavier precipitation is expected across
northeast OK/southeast KS into MO later this evening as a low-level
warm conveyer belt pivots to the north with a slow moving occluding
upper low in TX. As such, the later evening heavier precipitation
may reach the surface to efficiently freeze, with up to 0.03-0.06
in/3 hr rates possible in spots, especially in the 06-09Z period, as
suggested by the 12Z HREF, the last few runs of the HRRR, and by 01Z
RAP forecast soundings.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 36209549 36729557 37419514 38329347 38599201 38729129
38599083 38199044 37809037 37489065 37129131 36829196
36479291 36259470 36209549