721
FXUS01 KWBC 182043
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
442 PM EDT Tue Jun 18 2024

Valid 00Z Wed Jun 19 2024 - 00Z Fri Jun 21 2024

...Significant heavy rain/flash flooding threat with gusty winds
well ahead of Potential T.C. One expected to impact southern Texas
on Wednesday...

...Severe Thunderstorms and Excessive Rainfall possible over
portions of the Great Plains and Upper/Middle Mississippi Valley
tonight...

...A heat wave will persist over the Great Lakes, Ohio Valley and
the Northeast through midweek...


Potential T.C. One will likely strengthen while it slowly
approaches Mexico`s northeast coast tonight. This system carries
with it; coastal flooding, wind impacts, and a significant plume
of tropical moisture, which it is poised to transport into the
central Gulf Coast down to northeastern Mexico over the next
couple of days. There`s a Moderate Risk (at least 40%) of
Excessive Rainfall leading to Flash Flooding from the
Louisiana-Texas coast down to just north of Corpus Christi, Texas
where the heaviest axis of precipitation is likely to occur
tonight. A broader Slight Risk (at least 15%) of Excessive
Rainfall is also in place from the central Louisiana Gulf Coast
down to southern Texas. PTC One is then forecast to strengthen
into a Tropical Storm Wednesday afternoon before making landfall
over northeastern Mexico that evening. Tropical moisture will
likely continue to flow into southern Texas and the Rio Grande
Valley where yet another Moderate Risk of Excessive Rainfall is in
effect. T.S. One will quickly weaken upon landfall Wednesday night
before eventually diminishing Thursday evening. Additional heavy
rainfall may certainly continue over the Rio Grande Valley and
south Texas on Thursday before rainfall rates drop and conditions
improve. All in all, Potential Tropical Cyclone One is currently
forecast to produce rainfall totals of 5 to 10 inches from
northeast Mexico to south Texas, with maximum totals of 15 inches
possible.

A line of thunderstorms will develop out ahead of a cold front
sweeping across the Plains this afternoon. The Storm Prediction
Center issued a Slight Risk of Severe Thunderstorms from parts of
the Upper Mississippi Valley into the Mid Missouri Valley/Central
Plains and Southern High Plains where scattered to severe storms
are expected to produce large hail and severe/damaging winds. A
few tornadoes may also occur. Rainfall rates within some of these
storms to support Excessive Rainfall, which is why there is
currently a Slight Risk in effect from the Upper Midwest down to
the Central Plains.

Meanwhile, a heat wave continues to impact much of the Ohio
Valley, Great Lakes, Northeast and Mid-Atlantic this week.
Widespread daily records are likely for afternoon high
temperatures and warm overnight lows, with some monthly records
possible. Heat index readings are expected to peak from 100 to 105
degrees in many locations. Those without access to reliable air
conditioning are urged to find a way to cool down. Record warm
overnight temperatures will prevent natural cooling and allow the
heat danger to build over time indoors without air conditioning.
Conditions improve slightly this weekend.


Kebede


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php

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