827
FXUS02 KWBC 291817
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
217 PM EDT Wed Jul 29 2026

Valid 12Z Sat Aug 01 2026 - 12Z Wed Aug 05 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 break
down somewhat going into next 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 stretch of
weather. 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 Sunday into the beginning of next
week, thus keeping any excessive heat away through at least
Tuesday. That being said, it will still remain quite hot from the
Desert Southwest into Texas as the ridge hangs on longer there.


...Guidance/Predictability Assessment...

Model guidance continues to have a good overall handle on the
large scale pattern through most of the medium range period,
featuring an initially anomalously strong ridge over the Southwest,
troughing and a possible cut-off low over the central/eastern
U.S., and energetic troughing pushing from the Pacific Northwest
across the northern tier of the CONUS. Most of the uncertainty
stems from the speed of shortwaves embedded within the larger
troughs across the Northwest and Northeast, and how quickly they
track eastward. To mitigate these timing differences, a multi-model
composite blend of the EC, GFS, CMC, UKMET, and EC-AIFS was
utilized for fronts and pressures through day 5 before introducing
and increasing weighting of the EC and GEFS ensemble means for Days
6 and 7.


...Weather/Hazards Highlights...

Rainfall coverage is expected to increase across the Ohio Valley
and Mid-South on Saturday as a shortwave trough drops down from the
Great Lakes and possibly cuts off into a weak 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, leading to the potential
for 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 dangerous western U.S. heat wave is expected to reach peak
intensity on Saturday with highs at or above 100 degrees from
California to the northwestern High Plains. Numerous daily records
are likely to be set, and some high temperatures may come close to
setting monthly records for August. Record heat will likely persist
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 Texas to the Desert Southwest to
the Great Basin into California where the upper ridge remains
anchored in place 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.
Below average temperatures are likely across the Pacific Northwest
this weekend before a gradual warming trend ensues next week.
Meanwhile, temperatures across the eastern U.S. will remain
generally close to average through the period.


Miller/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


$$