MD 0003 Image

Mesoscale Discussion 0003
NWS Storm Prediction Center Norman OK
0607 AM CST Wed Jan 02 2019

Areas affected...Portions of north/central TX

Concerning...Freezing rain 

Valid 021207Z - 021600Z

SUMMARY...Light freezing rain, with rates around 0.05-0.10 inch per
3 hours, will be possible through mid-morning (around 16Z/10 AM

DISCUSSION...Ascent associated with the right entrance region of a
strong southwesterly upper-level jet is contributing to a swath of
precipitation this morning extending across parts of north/central
TX into the ArkLaTex region. A shallow, cold low-level airmass
remains in place over these areas, and continued moistening of the
column has resulted in generally light precipitation beginning to
reach the ground over the past couple of hours. The primary
precipitation type for the bulk of the precipitation shield is rain.
But, a relatively narrow southwest-to-northeast oriented corridor of
sub-freezing surface temperatures exists on the western edge of
light radar reflectivities, generally from near/just south of San
Angelo to the western portions of the Dallas/Fort Worth metro.
Temperatures well above freezing (5 to 8C) in the 850-700 mb layer
will completely melt hydrometeors aloft, while surface temperatures
at/below 32F across these areas will support light freezing rain
through at least mid-morning. Freezing rain rates of 0.05-0.10 inch
per 3 hours seem reasonable given the mostly weak reflectivities
noted on radar so far this morning, and this scenario is generally
depicted in most recent short-term guidance. A somewhat better
potential for ice accretion should exist where surface temperatures
of 27-30F are present. Modest diurnal heating will warm the low
levels by mid-morning (around 16Z/10 AM CST). Accordingly, as
surface temperatures begin to climb above freezing, this will likely
reduce the freezing rain threat.

..Gleason.. 01/02/2019

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


LAT...LON   30449978 30340078 30520091 31580046 32409979 32989912
            33399853 33379758 33219714 32249756 31639819 30999889

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