SPC MD 1755

MD 1755 CONCERNING WINTER MIXED PRECIPITATION FOR FAR EAST-CENTRAL NM...MUCH OF THE TX PANHANDLE...WESTERN OK/EASTERN OK PANHANDLE

Mesoscale Discussion 1755
NWS Storm Prediction Center Norman OK
0117 AM CDT Mon Oct 26 2020

Areas affected...Far East-Central NM...Much of the TX
Panhandle...Western OK/Eastern OK Panhandle

Concerning...Winter mixed precipitation 

Valid 260617Z - 261015Z

SUMMARY...Mixed winter precipitation, predominantly sleet, is
expected this morning from far east-central NM across the TX
Panhandle into western OK.

DISCUSSION...Regional radar imagery has shown an increase in
precipitation coverage during the past few hours as isentropic
ascent persists across the southern Plains/southern High Plains. 00Z
AMA sounding sampled a shallow cold layer well, revealing a cold
layer extending to 850 mb (about 1 km deep). Above this cold layer,
warm temperatures associated with the persistent southwesterly flow
aloft resulted in a strong inversion, with 700 mb temperatures near
7 to 8 deg C. This results in a thermodynamic profile supporting
mixed precipitation, predominantly sleet, once the mid-level layer
moistens enough to erode the dry layer in place. The increase in
precipitation coverage noted in regional radars is likely evidence
of that ongoing moistening process, which is expected to continue
and will soon support precipitation reaching the surface over much
of this region. 

Given the anticipated persistence of the southwesterly flow aloft
and resulting maintenance of the warm layer aloft, the expectation
is for an area of mixed winter precipitation to develop from far
east-central NM across the TX Panhandle in western OK/eastern OK
Panhandle. Sleet is expected to be the dominant precipitation type.
Additionally, elevated instability, based the at the top of the warm
layer around 700 mb, could contribute to higher precipitation rates
as well as occasional lightning. Current observations show lightning
within the precipitation band from Potter County TX into Harper
County OK.

..Mosier.. 10/26/2020

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

ATTN...WFO...OUN...DDC...LUB...AMA...ABQ...

LAT...LON   35500332 36190236 37200002 36959882 36039911 35399962
            34630075 34150235 34130337 34390375 34850375 35500332 

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