278
AWUS01 KWNH 100110
FFGMPD
TXZ000-OKZ000-NMZ000-100600-

Mesoscale Precipitation Discussion 0415
NWS Weather Prediction Center College Park MD
909 PM EDT Sun Jun 09 2024

Areas affected...High Plains of NM through the southern Panhandle
of TX

Concerning...Heavy rainfall...Flash flooding likely

Valid 100109Z - 100600Z

Summary...Showers and thunderstorms will become increasingly
widespread this evening across the southern Panhandle of Texas and
into eastern New Mexico. Rainfall rates will likely eclipse 2"/hr,
which through slow storm motions and repeated clusters could
produce 2-3" of rain with local amounts to 5". Instances of flash
flooding are likely.

Discussion...The regional radar mosaic has become quite impressive
this evening, with widespread convection and heavy rain developing
from the Hill Country of TX through the Cap Rock and into the High
Plains of NM. These storms are generally unfocused and
disorganized pulse in a region of very weak shear, but are
widespread thanks to significant forcing. A warm front analyzed by
WPC is wavering across the region, while a convectively enhanced
shortwave emerges from NM. At the same time, moisture confluence
is intensifying along the warm front, providing a focus for
convergence and ascent into a ribbon of MLCAPE exceeding 2000 J/kg
overlapped with 1.4 to 1.6 inch PWs. Despite the weak shear, this
intensifying ascent into the robust thermodynamics is driving
rapid convective growth primarily along the warm front, but also
along residual outflow boundaries and within any storm
collisions/mergers. Rainfall rates have been estimated above 2"/hr
according to KLBB WSR-88D, which has already produced some
instances of flash flooding despite modest residence times of
these rates.

The high res continues to under-forecast the current coverage, but
the overall evolution of the recent HRRR runs appears reasonable.
The northeast advance of the shortwave out of NM combined with a
subtle surge of 850mb inflow from the south to advance the warm
front back to the north should cause additional thunderstorm
development into tonight. Mean 0-6km winds of just 5-10 kts
suggests convection will drift north/northeast, while Corfidi
vectors aligned back to the SE at 10-15 kts indicate some training
potential. Additionally, the lack of meaningful shear suggests
storms will continue to pulse up with the accompanying outflows
driving secondary ascent, while storms lifting off the terrain in
NM could congeal and drop into the High Plains, providing
additional focus for heavy rainfall.

This will likely result in some areas receiving a long duration,
or multiple rounds, of heavy rainfall with rates exceeding 2"/hr
as forecast by HREF hourly rain probabilities for 2 inches
reaching 20-25%. Where this occurs, amounts of 2-3" with up to 5"
are possible as reflected by the HREF. This will be falling atop
soils that are generally dry according to NASA SPoRT, but still
feature some 3-hr FFG as low as 1.5-2.5". This has a 40%-50%
chance of exceedance tonight, suggesting instances of flash
flooding are likely.

Weiss

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...ABQ...AMA...FWD...LUB...MAF...OUN...SJT...

ATTN...RFC...ABRFC...WGRFC...NWC...

LAT...LON   36830442 36390345 35990274 35120159 34550008
            34379964 33989871 33069875 32730011 32740185
            33150312 33910418 34620468 35330505 36060505