564
FXUS01 KWBC 010810
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
409 AM EDT Mon Jul 01 2024

Valid 12Z Mon Jul 01 2024 - 12Z Wed Jul 03 2024

...Dangerously hot conditions will continue across the southern
Plains and lower Mississippi Valley, while simmering heat builds
throughout California`s Central Valley starting Tuesday...

...Heavy rain and flash flooding likely across parts of the
Southeast coastline today...

...Severe thunderstorm and heavy rain threat situated over
northern Plains and Midwest early this week...


July kicks off with anomalous and potentially dangerous heat
impacting the south-central U.S. and portions of the West Coast.
As of this morning, over 50 million residents are under
heat-related watches, warnings, and advisories. The upper-level
pattern throughout the next few days responsible for the summer
heat consists of ridging just off the West Coast and over the
lower Mississippi Valley, while an upper trough situates over the
northern Rockies and northern Plains. For the central U.S., high
temperatures are forecast to soar into the upper 90s and low 100s
across the southern Plains through midweek. When combined with
elevated humidity levels, heat indices are forecast to rise into
the 110s across the lower Mississippi Valley and Gulf Coast.
Excessive Heat Warnings and Heat Advisories currently span from
Kansas to the Gulf Coast States. After enjoying a refreshing start
to the workweek, the Midwest and East Coast can expect a gradual
return to muggy summer warmth by Wednesday as surface high
pressure reorients itself off the East Coast and ushers in
southerly flow. Extreme heat building throughout the West Coast
and more specifically interior California this week will also be
particularly dangerous for those without effective cooling. High
temperatures away from the immediate coastline are forecast to
reach into the 100-110F range, which could break numerous daily
records in the San Joaquin and Sacramento valleys on Tuesday and
Wednesday. Excessive Heat Warnings, Watches, and Heat Advisories
go into effect as early as Tuesday and span from southern Oregon
to the low desert of southeast California. The duration of this
heat wave is concerning as the current forecast keeps scorching
conditions in place through at least the end of the week. This
level of heat could pose a danger to the entire population if
proper heat safety is not followed. This includes staying
hydrated, out of direct sunlight, and in properly air-conditioned
buildings. Additionally, it is very important to check on
vulnerable friends, family, and neighbors to confirm their safety.

A cold front sliding down the East Coast today is forecast to slow
its southerly motion as it intersects the Southeast coastline,
with developing thunderstorms along the boundary. Some storms are
expected to contain intense rainfall rates and slow propagation,
which creates the threat for flash flooding. Parts of the South
Carolina coastline, including the city of Charleston, has been
highlighted as having a Moderate Risk (level 3/4) of Excessive
Rainfall today. Areas most at risk for flooding are locations with
poor drainage, where heavy rainfall coincides with the afternoon
high tide, and in urbanized communities. Be sure to remain weather
aware and always remember to never drive through flooded roads.

Additionally, a storm system exiting the northern Rockies this
morning is anticipated to create some pre-Independence Day
fireworks across the northern Plains and Midwest through midweek
as the threat of heavy rain and severe weather slides eastward
with time. Severe thunderstorm chances are centered over Nebraska
South Dakota today, with neighboring states included in the
potential for potent thunderstorms capable of containing damaging
wind gusts and sporadic hail. Of potentially greater concern
throughout the upper Mississippi Valley is the prospect for more
heavy rainfall over saturated soils and swollen rivers. As
approaching frontal boundaries provide a focus for several
clusters of thunderstorms, areas of intense rainfall rates are
possible throughout the northern Plains and upper Midwest today
before sliding gradually eastward on Tuesday, but still remaining
centered over the Midwest. Probabilities for at least 1 inch of
rain are high (70-90%) for much of Iowa, eastern Nebraska,
southern Minnesota, central/southern Wisconsin, and far northwest
Illinois through Tuesday. This next round of heavy rain could
create instances of flash flooding as well as exacerbate ongoing
river flooding across areas still recovering from last week`s
heavy rainfall.

Continued sufficient moisture content over the Southwest and
southern Rockies will also aid in the development of daily showers
and thunderstorms capable of producing localized instances of
flash flooding. Regions most likely to be affected by scattered
downpours include Arizona, New Mexico, and southwestern Colorado,
with burn scars and sensitive terrain the most at risk for flash
flooding.

Snell


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