776
FXUS02 KWBC 260745
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
345 AM EDT Sun Jul 26 2026

Valid 12Z Wed Jul 29 2026 - 12Z Sun Aug 02 2026

***Lengthy heat wave expected for much of the Western and Southern
 U.S. through next weekend***


...Pattern Overview...

The main theme going into the middle of the week will be a large
upper ridge situated across the Rockies and western High Plains,
and extending northward into south-central Canada. An upper trough
with a closed low is expected over the Northeast Pacific, and a
more amplified trough over the Northeast states will likely
support periods of heavy rainfall on Wednesday. This general
pattern holds true going into the end of the week as the ridge
expands farther to the west to include the Intermountain West, and
general troughing likely continues for the East Coast with some
abatement in rainfall coverage as the deep moisture plume exits the
coast. Daily afternoon and evening thunderstorms are expected from
the central Rockies to the Desert Southwest with plenty of
monsoonal moisture in place south of the closed upper high.


...Guidance/Predictability Assessment...

The 00Z model guidance suite is in good overall agreement on the
synoptic scale pattern across the Continental U.S. through the
middle to end of the week, with a general deterministic model
compromise serving well as a starting point in the forecast
process. Looking ahead to the weekend, the models agree best on
the upper ridge expanding across the West (with potential for a
600dm high centered over Utah by late Friday). There has been an
improvement with model agreement across the Eastern U.S. with
maintaining the general trough pattern and the trough moving inland
from the northeast Pacific to southern Canada. The ensemble means
were gradually increased to about 50% by Saturday.


...Weather/Hazards Highlights...

Extreme heat will continue to make weather headlines across a large
expanse of the country going into next week. Widespread upper 90s
and low 100s are expected from Montana to the western Dakotas,
which is 10-15 degrees above average in many cases. It will also be
very hot and humid from Texas to the Gulf Coast states with highs
ranging from 95 across the Deep South to 105 degrees for central
Texas on most days, with some areas of extreme heat risk given the
longevity of the heat and expected heat indices exceeding 110
degrees at times. It will also be quite hot from the Desert
Southwest and extending north across the Intermountain West with
the upper ridge exerting its influence, with 110s for the lower
elevations of southern Arizona and southern interior California,
and near 100 degrees northward to the greater Salt Lake City area.
Overnight lows will also be above normal for many of these same
areas. The opposite will likely be the case for the East Coast with
readings near average or slightly below.

An organized low pressure system crossing the Northeast U.S. on
Wednesday, in combination with an amplifying upper level shortwave
trough, will fuel the development of numerous showers and storms
from upstate New York to New England. A Slight Risk of excessive
rainfall will be valid for portions of southern New England given
the potential for 1-2 inches of rainfall, with locally higher
amounts with the stronger storms, which could be enough to produce
flooding for some areas. There may be some lingering rainfall
across eastern New England Thursday as the low pressure system
slowly departs the region.

Elsewhere across the country, monsoonal moisture will remain
in place from eastern Arizona to central New Mexico, and extending
northward across the Colorado Rockies. Scattered to numerous
showers and storms are expected most days, with some abatement in
coverage going into the weekend. Farther east across the Plains
and Midwest, northwest flow aloft around the northeastern
periphery of the upper ridge should support the development of some
mesoscale convective complexes.

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




$$