121
AWUS01 KWNH 080043
FFGMPD
TXZ000-080630-

Mesoscale Precipitation Discussion 0586
NWS Weather Prediction Center College Park MD
842 PM EDT Sun Jul 07 2024

Areas affected...Portions of the Midde to Upper Texas Coast

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

Valid 080041Z - 080630Z

SUMMARY...Significant flash flooding likely as the northern
eyewall bands of T.S. Beryl begin to move ashore. Expect
consistent 2 to 4 inch per hour rainfall rates to begin shortly
along the coast, gradually spreading inland.

DISCUSSION...Tropical Storm Beryl is approaching the Middle to
Upper Texas Coast this evening. The intensifying cyclone has been
organizing its rainbands around the developing eye over the past
few hours as it contends with dry air entrainment. The remnant dry
air adds a bit of uncertainty as to rainfall amounts across this
area through the first half of the overnight, as the latest 4pm
CDT NHC forecast discussion suggests rapid intensification is
still possible prior to landfall. Rapid intensification would
entail intensifying rainbands associated with Beryl, and
increasing rainfall rates.

Prior to now, any rainfall associated with Beryl`s outer rain
bands have been heavy at times, but the bands have subsequently
fallen apart as they move onshore and were fast enough moving over
an area with relatively dry soils that flash flooding has not been
a major concern. Going forward however, steady and increasingly
heavy rainfall is expected along the coast as the center of Beryl
approaches. Thus, the flash flooding threat will rapidly increase
with each successive hour of heavy rainfall.

A portion of the area around and south of Houston was hit with
heavy rainfall yesterday, resulting in a subsequent lowering of
FFGs...with hourly FFGs between 2 and 2.5 inches where normally
they`re between 3 and 3.5 inches. This lowering will make flash
flooding occur more quickly once the rainfall becomes steady.

With both heavy rainfall and hurricane force winds likely along
and near the coast, flash flooding impacts will also quickly
increase with time both due to prior rainfall and debris clogging
local storm drains. Locally significant flash flooding is likely
and catastrophic flash flooding is possible through the evening
along the coast. For the Houston metro, expect increasingly
frequent heavy rainfall with some chance of the heavy rain
becoming steady by the end of the period, though the worst
conditions in Houston are likely to hold off until after the valid
time of this MPD.

An updated MPD will be issued by 0630Z.

Wegman

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

ATTN...WFO...CRP...EWX...HGX...

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

LAT...LON   30019619 29939518 29679479 29499459 29379466
            28799546 28209661 27789707 28679731 29549697