745
FXUS01 KWBC 190835
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
433 AM EDT Wed Jun 19 2024

Valid 12Z Wed Jun 19 2024 - 12Z 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
today...

...A heat wave will persist over the Midwest, Great Lakes, Ohio
Valley and the Northeast into late week...

...Thunderstorms and heavy rain become less active across the
north-central today into Thursday but may reload across the
northern Plains Thursday night/early Friday...

With the last piece of the potent upper-level energy exiting into
southern Canada, the weather across the northern tier states will
be less busy than recent days.  Meanwhile, Potential Tropical
Cyclone One (PTC1) is making a headline as the heavy rain and
tropical-storm-force winds well north of the center of circulation
are poised to move onshore and head inland across southern Texas
today.  It appears that the lower and middle Texas coasts will be
the locations that will most likely be impacted by the heavy rain
and gale force winds.  A coastal front may enhance the heavy
rainfall just inland from the coast but how sharp this front will
get remains to be seen.  Meanwhile, the strong Bermuda High that
will help sustain the heat wave across the Ohio Valley to the
Northeast will also help steer PTC1 westward toward northern
Mexico today as PTC1 could acquire tropical storm (TS) status
before making landfall early on Thursday.  The heavy rain well
north of TS1 will likewise move west across southern Texas and
into the Rio Grand Valley through tonight, resulting in rainfall
totals of 5 to 10 inches from northeast Mexico into South Texas
with maximum totals of 15 inches possible.  Winds associated with
TS1 will weaken rapidly over northern Mexico as the heaviest
rainfall is forecast to move west of the Rio Grand Valley into
northern Mexico and begin to taper off early on Friday.
Meanwhile, some of the tropical moisture from TS1 is forecast to
stream north and trigger showers and thunderstorms across the Four
Corners region by Thursday and into Friday.  Over the western
Atlantic, moisture associated with a tropical wave could reach
northeastern Florida and coastal Georgia Thursday night to Friday
morning.

As the aforementioned upper-level energy and associated low
pressure system moves farther into Canada, the thunderstorms and
heavy rain from the central Plains to the upper Midwest will
become less active today.  The trailing front from the low will
become nearly stationary from west to east across the northern
tier states during the next couple of days.  The next piece of
upper-level energy ejecting from the central Rockies will begin to
interact with the stationary front late on Thursday and
reinvigorate heavy rain and strong thunderstorms across the
northern Plains and toward the upper Midwest into Friday morning.
Scattered thunderstorms will also extend farther east across the
Great Lakes into interior New England.

Meanwhile, a heat wave will continue to impact areas from the
Midwest into much of the Ohio Valley, Great Lakes, Northeast and
Mid-Atlantic through the next few days.  Afternoon high
temperatures and warm overnight lows will likely challenge daily
records and even some monthly records.  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 are expected to
improve over New England this weekend.

Kong/Kebede


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

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