Today Through the Fourth Friday (22 to 28 days) Weather Outlook for the U.S. and a Six-Day Forecast for the World: posted June 22, 2024
This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks and a six-day World weather outlook which can be very useful for travelers.
First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.
Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sat Jun 22 2024
Valid 12Z Sat Jun 22 2024 – 12Z Mon Jun 24 2024…Heat wave focus shits from the Midwest/Ohio Valley into the
Mid-Atlantic states this weekend...…Heavy rain and flash flooding concerns across the Upper Great
Lakes/Mississippi Valley Saturday and northern New England Sunday……Heat building across the West this weekend, monsoon-like conditions for
the Desert Southwest…A heat wave will continue over much of the eastern U.S. south of a
quasi-stationary boundary and under the influence of longwave ridging
aloft this weekend. Forecast high temperatures Saturday will generally be
in the mid- to upper 90s from the central/southern Plains to the East
Coast. These temperatures remain the most anomalous and dangerous for
early Summer over portions of the Midwest/Ohio Valley east to the
Mid-Atlantic. Heat-related advisories and warnings are in place as
humidity will bring heat index values as high as the mid-100s. A potent
upper-level shortwave will help to finally push the boundary southward
Sunday, bringing welcome relief to much of the Midwest/Ohio Valley, while
the Mid-Atlantic continues to simmer. Numerous record-tying/breaking highs
are possible. In addition, overnight low temperatures will remain to the
mid- and even upper 70s, providing little relief from the heat overnight.
The combination of this heat coming early in the Summer season and
persisting over several days increases the level of heat stress for those
without reliable air conditioning.Widespread showers and thunderstorms will continue to the north along the
quasi-stationary boundary draped from New England west through the Great
Lakes and into the Upper Mississippi Valley. Plentiful moisture will
increase the chance for locally heavy downpours. The highest chance for
potentially significant heavy rainfall will be along the boundary ahead of
an upper-level wave over portions of the Upper Great Lakes/Upper
Mississippi Valley Saturday. Ongoing organized storms from overnight
Friday as well as the risk for more widespread, organized storms into the
day Saturday has prompted a Moderate Risk of Excessive Rainfall (level
3/4) over southern Wisconsin and northeastern Iowa for the threat of
scattered to numerous instances of flash flooding. A broader Slight Risk
(level 2/4) covers the region. In addition, a few storms may be severe,
with a Slight Risk of severe weather (level 2/5) issued by the Storm
Prediction Center for the threat of some damaging winds and a few
tornadoes. A locally higher threat for heavier downpours will also exist
over southern New England, with a Slight Risk in place. The noted more
potent upper-level shortwave arriving Sunday will help to push the
boundary south and eastward, bringing higher storm chances more broadly
across New England and southwestward though the Mid-Atlantic/Ohio
Valley/Tennessee Valley. Stronger, very moist low-level flow interacting
with the boundary over northern New England will bring the greatest chance
for heavy downpours and scattered flash flooding, with another Slight Risk
in place. A Slight Risk for severe weather also covers much of the same
region and southwestward into the northern Appalachians/Upper Ohio Valley,
where damaging winds and a few tornadoes will once again be the main
threats.Upper-level ridging will begin to build over the western and then central
U.S. following the shortwave passage, bringing rising temperatures across
this region as well. Forecast highs Saturday across much of the interior
Pacific Northwest, Great Basin, and California will be in the mid-90s to
low 100s. Locally higher temperatures into the mid-100s have prompted
heat-related advisories and warnings for the central California Valleys
into portions of southern California. The focus over the northern tier
will begin to shift eastward with the ridge on Sunday, with cooler highs
in the Pacific Northwest but temperatures soaring into the mid- and upper
90s over much of the central/northern High Plains. Conditions will remain
hot from central to southern California. Temperatures will still be hot
but closer to average for the Desert Southwest as Monsoon-like conditions
remain over the region. Highs Saturday and Sunday will range in the mid-
to upper 100s, with scattered showers and storms bringing the threat for
some locally heavy downpours and an isolated risk for flash flooding.
Elsewhere, a pair of waves of low pressure passing over portions of the
Southeast/Florida as well as south Texas will bring daily shower and storm
chances.