Mesoscale Precipitation Discussion 0022
NWS Weather Prediction Center College Park MD
955 AM EST Tue Jan 23 2024

Areas affected...Northeast TX through Central AR

Concerning...Heavy rainfall...Flash flooding possible

Valid 231455Z - 232055Z

SUMMARY...Some increase in the concentration of heavy rainfall is
expected over the next several hours across the Arklatex region.
Given the wet antecedent conditions, these rains may result in
some runoff problems with at least a localized threat of flash
flooding.

DISCUSSION...GOES-E IR satellite imagery has been showing cooling
cloud tops associated with an area of heavy rainfall and embedded
elevated convection across northeast TX over the last few hours.
This concentration of heavy rainfall is being driven in part by an
upper-level jet max crossing the region downstream of a deep layer
trough over the Southwest, and this energy is interacting with a
modest pool of elevated instability with MUCAPE values of 500 to
1000 J/kg. Additionally, there is an increasingly moist and
convergent low-level flow regime emanating off the western Gulf of
Mexico and this is nosing northward toward the broader Arklatex
region.

The low-level jet will gradually be strengthening going through
the late morning and early afternoon hours, and the speed
convergence associated with the nose of this jet coupled with
increasing PWs should facilitate some increase in rainfall rates.
Some broader expansion of elevated convection is also expected
over the next 3 to 6 hours, given the aforementioned larger scale
jet energy aloft/forcing and some localized uptick in instability.
Some rainfall rates with the stronger convective elements are
expected to reach into the 0.50" to 0.75"/hour range.

The 06Z HREF guidance and the recent HRRR guidance has generally
been on the slow side with the current evolution of heavy
rain/convection, but does support the axis of heavy rains
advancing northeastward toward central AR in time. Some additional
rainfall totals going through early to mid-afternoon may reach 1.5
to 2.5 inches.

Given the localized persistence of the heavy rainfall over the
next several hours, and wet antecedent conditions, these rains may
result in some runoff problems including a threat for localized
flash flooding. This will include some of the more sensitive urban
locations as well.

Orrison

ATTN...WFO...FWD...LZK...SHV...

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

LAT...LON   35009279 34819213 34109230 32899325 31969465
            31609599 32009661 32459641 33419539 34469408