Prognostic Meteorological Discussion
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740
FXUS02 KWBC 290755
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
355 AM EDT Wed Jul 29 2026

Valid 12Z Sat Aug 1 2026 - 12Z Wed Aug 5 2026


***Hot weather continues for the Intermountain West and the Desert
 Southwest with daily record highs likely***


...Pattern Overview...

The large upper ridge that will be governing the overall weather
pattern across the western half of the country will start to shrink
some going into the week. This will be due to a strong closed upper
low/trough moving into southwestern Canada, with a trailing cold
front bringing a welcomed cool down from the Pacific Northwest to
the Northern Plains after a very hot week. Meanwhile, an amplifying
trough over the Midwest and then the Mid-South will lead to
increased showers and thunderstorms from the Gulf Coast to the
Northeast going into Sunday and the beginning of the work week,
thus keeping any excessive heat away from the Eastern U.S. through
Tuesday. It will still remain quite hot from the Desert Southwest
into Texas since the cold front will not make it that far south.

...Guidance/Predictability Assessment...

The 00Z model guidance suite features good overall synoptic scale
agreement across the Continental U.S. going into next weekend,
with the best agreement noted on the closed upper high positioned
across the southwestern quadrant of the country. There has been
good run-to-run continuity since the 12Z guidance in most cases
through Monday, and the most recent GFS has trended closer to the
model consensus with the trough across the Northeast early in the
week compared to its 18Z run, which was a much stronger solution
compared to the existing guidance. The ECMWF/AIFS/ECENS hold onto a
broad upper low/trough over the Ohio Valley and the Mid-South
longer than the CMC/GFS guidance through Tuesday. In terms of the
NBM, it appeared reasonable as a starting point for most areas,
although some modest downward adjustments were made for portions of
the interior Northwest into the Dakotas behind the cold front to be
closer to the model consensus. The ensemble means were gradually
increased to about 40% by next Wednesday.

...Weather/Hazards Highlights...

The Ohio Valley and Mid-South are expected to get an increase in
rainfall coverage for Saturday as a shortwave trough drops down
from the Great Lakes and possibly becomes a weak cut-off upper low.
A more concentrated area of heavier rainfall will be possible from
the central Gulf Coast to northern Florida with enhanced moisture
convergence south of the frontal boundary, with some rainfall
totals in excess of two inches over the weekend. Showers and
thunderstorms increase more broadly across the East Coast states in
general for Sunday into Monday as deeper moisture is advected
northward ahead of the upper trough across the Mid-South,
potentially more concentrated across the central and southern
Appalachians.

The western U.S. heat wave is expected to be worst on Saturday with
highs at or above 100 degrees from California to the northwestern
High Plains. The potential exists for numerous daily records to be
set, and some possibly close to monthly records for August. There
will likely be some record heat going into Sunday as well, but only
extending up to central Wyoming since a cold front will be passing
through Idaho and Montana. The hottest readings for the weekend
will be across the lower elevations of the Desert Southwest where
widespread 110s are forecast, and even some lower 120s for the
normally hottest locations! Record high overnight lows are also
likely, including locations farther to the east across Texas with
lows struggling to get below 80 degrees. It will remain
uncomfortably hot going into the first half of next week from
California to Utah and southward to Arizona where the upper ridge
persists the longest.

Elsewhere across the Continental U.S., most of the monsoonal
rainfall should be confined to eastern Arizona and into New Mexico,
with scattered convection reaching into portions of Utah and
Colorado. A corridor of showers and storms is likely ahead of the
front that crosses the Dakotas and into Minnesota early in the
week, and this may also be accompanied with some severe weather.
The Pacific Northwest will likely have some below average
temperatures this weekend before a gradual warm-up ensues next
week, and generally close to average for the eastern U.S.

Hamrick




Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast, excessive rainfall outlook,
winter weather outlook probabilities, heat indices and Key Messages
are at:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw
















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