650
FXUS01 KWBC 301956
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
355 PM EDT Sun Jun 30 2024

Valid 00Z Mon Jul 01 2024 - 00Z 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...

...Severe thunderstorm and heavy rain threat for the East Coast
today; a Moderate Risk for Excessive Rainfall has been posted for
portions of the Southeast coast for Monday...

...Showers and thunderstorms for the Four Corners/Southwest over
the next few days; active weather pattern to produce some
pre-Independence Day fireworks in the Northern Plains and
Midwest...

As the calendar prepares to flip over to July tomorrow, sweltering
summer heat will be one of the top stories in the days leading up
to Independence Day. To start the week, strong upper level high
pressure over the South will be responsible for heat indices that
range between 105-110F (locally up to 115F) through Tuesday from
the Southern Plains on east to the Lower Mississippi Valley. Much
of these regions have Excessive Heat Warnings and Heat Advisories
that are in place through at least Monday. Meanwhile, California
and Desert Southwest will gradually heat up as another impressive
upper level ridge of high pressure builds in over the northeast
Pacific on Tuesday. Daily record highs may be challenged in parts
of central California and heat indices in the Golden State`s Great
Valley may approach 105F. This approaching heat dome along the
West Coast will likely be a fixture for Californians and
eventually for more residents along the West Coast by Independence
Day. On the flip side, following an oppressively hot Sunday in the
Northeast, the strong cold front responsible for today`s
widespread shower and thunderstorm activity will usher in a more
refreshing air-mass tonight. High pressure over the Great Lakes
tomorrow is set to lock in pleasant weather across the
northeastern U.S. through Tuesday. The other regions likely to
experience cooler than normal temperatures the first couple days
of July are the Northern Rockies and northern Great Plains as
northwesterly flow keeps any excessive heat at bay in the short
term.

In terms of active weather, the evening will remain quite busy
along and east of I-95 this evening from southern New England on
south to the Mid-Atlantic states. The severe threat will conclude
for interior parts of the Northeast this afternoon as the cold
front races south and east. Some thunderstorms could be severe
this evening, particularly from North Carolina to as far north as
Maine where the Storm Prediction Center has a Slight Risk (threat
level 2/5) in place. The area most at risk for severe weather is
from the Delaware Valley to southern New England where SPC has
issued an Enhanced Risk (threat level 3/5). There is also an
opportunity for these storms to pose a flash flood threat along
the East Coast as evident in a lengthy Marginal Risk area (threat
level 1/4) that stretches from southern New England all the way to
South Florida. By Monday, the front cold front will end up in the
Southeast where a surplus of rich atmospheric moisture and ample
instability will favor not only strong-to-severe thunderstorms
capable of producing torrential downpours, but training lines of
thunderstorms in some cases. WPC has issued a Moderate Risk
(threat level 3/4) for portions of the Southeast coast that
include cities such as Savannah, GA and Charleston, SC. Localized
rainfall totals in these areas could surpass 6 inches where the
heaviest thunderstorms occur. Elsewhere, anomalous moisture
content in the Four Corners region will provide scattered
thunderstorms in the Southern Rockies with more than enough
moisture to produce Excessive Rainfall rates. WPC has a pair of
Slight Risks (threat level 2/4); one in southern Arizona and
another in parts of the Central Rockies. By Monday and Tuesday,
the moisture content is not as impressive, but given the presence
of lingering monsoonal moisture and some soils in the region
growing more sensitive, a Marginal Risk for Excessive Rainfall is
present for both days across parts of the Four Corners region.

Farther north, a potent upper level trough traversing the Northern
Rockies will be the catalyst for numerous showers and
thunderstorms this afternoon and evening. SPC does have a Slight
Risk across much of southern Montana today with a Marginal Risk
(threat level 1/5) that extends as far south as the Denver metro
area and as far east as the western Dakotas. By Monday, a
strengthening area of low pressure in the northern Great Plains
will be the focus for more severe weather and Excessive Rainfall.
Both WPC and SPC have Slight Risks in place across a large section
of the North Central U.S.. SPC`s Slight Risk encompasses more of
the northern Great Plains, while WPC`s Slight Risk for Excessive
Rainfall includes more of the Upper Midwest where soils remain
overly saturated and river/stream flooding is still ongoing. The
storm system continues to track east on Tuesday with the Midwest
and Central Plains forecast to see the brunt of the severe weather
and heavy rainfall. Both WPC and SPC have hoisted Slight Risks for
Excessive Rainfall and severe weather for portions of these
regions on Tuesday. With additional heavy rainfall in parts of the
Midwest, it is possible this rainfall will either renew or
exacerbate the ongoing river/stream flooding in parts of the Upper
Mississippi Valley through mid-week.

Mullinax


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