Today Through the Fourth Friday (22 to 28 days) Weather Outlook for the U.S. and a Six-Day Forecast for the World: posted September 4, 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
Wed Sep 04 2024
Valid 12Z Wed Sep 04 2024 – 12Z Fri Sep 06 2024…Heat wave builds over the Southwest and the West Coast this week…
…Heavy rain and flash flood potential continues for the Gulf Coast
states the next couple of days…An upper-level ridge building northward over the West Coast will help to
expand and intensify a heat wave over the region through the next few
days. Forecast highs today (Wednesday) range from the upper 100s to
mid-110s in the Desert Southwest, the mid-90s to low 100s for southern and
central California, and the mid-90s to low 100s for portions of the
Pacific Northwest. Temperatures soar even higher on Thursday, with highs
into the 110s for the Desert Southwest, the 100s to near 110 in southern
California, the mid-100s for the central California Valleys, and the low
100s for portions of the Pacific Northwest. Widespread heat-related
warnings and advisories are in place as the threat for heat-related
illness and impacts will increase today and especially on Thursday. This
heat will be dangerous to anyone without effective air conditioning or
sufficient hydration. While not quite as hot, temperatures will also be
well above average along the immediate Pacific Coast, with highs into the
80s for many locations.Heavy rain and the threat for flash flooding will remain in the forecast
for the Gulf Coast states this week as a stationary front and coastal low
drive multiple days of widespread showers and thunderstorms across the
region. The placement of the elongated area of low pressure in the western
Gulf will keep the focus for the most widespread rainfall over portions of
the central and upper Texas Gulf Coasts, and possibly a bit further north
into the Lower Mississippi Valley. Extremely moist Gulf air will lead to
very heavy downpours (upwards of 2-3″ per hours rates) with continued
rounds of storms moving onshore. Forecast areal average rainfall totals
are in the 3-5″ range, with locally higher amounts of 7″+ possible, most
likely near the immediate coast. A Slight Risk of Excessive Rainfall
(level 2/4) is in place for the region both today and tomorrow given the
threat for scattered instances of flash flooding. Storms will also
increase along the southeastern Atlantic Coast today and Thursday, and
daily thunderstorm chances will continue for the Florida Peninsula. The
passage of the frontal boundary to the coast and widespread storms and
clouds will keep temperatures down across Texas and the Southeast the next
couple of days, with highs generally in the 80s. Conditions will be hotter
south of the boundary in Florida with temperatures into the 90s. A Heat
Advisory is in place for South Florida today as the combination of highs
into the 90s and high humidity will lead to heat indices in the 105-110
degree range.Elsewhere, much of the eastern U.S. outside of the the South will be dry
with generally mild temperatures. Early Fall-like highs in the 70s are
expected throughout New England, the Mid-Atlantic, and Carolinas through
Thursday. An upper-level ridge passing over the Midwest will bring
temperatures back up into the mid- to upper 80s over the next couple of
days. An approaching upper-level trough/surface frontal system will bring
shower and thunderstorm chances to portions of the Central/Northern Plains
and Upper Midwest today, with the greatest storm coverage and chance for
some more moderate rainfall in the Upper Midwest and the central High
Plains/adjacent Rockies. The frontal system will push further
southeastward on Thursday, bringing storm chances to the Great Lakes,
Central Plains, and central/southern High Plains/adjacent Rockies. Once
again, the greatest storm coverage and heavier rainfall will be focused to
the north over the Great Lakes and to the southwest over the
central/southern High Plains and adjacent Rockies. Some isolated flash
flooding will be possible over the southern Rockies given more sensitive
soils from recent rainfall and over any burn scars.