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