639
FXUS02 KWBC 221959
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
359 PM EDT Wed Jul 22 2026

Valid 12Z Sat Jul 25 2026 - 12Z Wed Jul 29 2026


...Southeast U.S. Heavy Rainfall/Flooding threat into Saturday...

...West-Central to Southern U.S. Hazardous Heat this weekend into
next week as monsoonal rains focus over the Four Corners states...


...Pattern overview and Guidance/Predictability Assessment...

Models are in very good agreement regarding the overall synoptic
evolution across the CONUS during the medium range. A relatively
stagnant pattern featuring mean troughing along the West and East
Coasts and a large ridge over the Central U.S. will persist through
the middle of next week. This pattern will likely yield heat risk
concerns across the Central U.S.. A shortwave disturbance
propagating through the northern stream will dive into the Eastern
U.S. next week, bringing more excessive rainfall potential to
parts of the Northeast and recently drenched Mid-Atlantic.

A general model blend consisting of the available deterministic and
Ai guidance was good enough to capture the rather simple pattern
across the CONUS through day 6. Timing of the shortwave propagating
through southern Canada and into the Northeast is a point of
uncertainty between the models, but not much variability on the
larger scale features.

...Weather/Hazards Highlights...

Broad upper ridge influence offers Major to Extreme HeatRisk
threat areas broadly this weekend into next week from the
Southwest/Intermountain West/Rockies through the Northern Plains
down through the south-central U.S. and the South. Expect spotty
record highs and more widespread record overnight lows to limit
relief from the heatwave.

Some moderating flow with and around the western periphery of the
upper ridge will occur as significant monsoonal moisture feeds into
the Southwest and Intermountain West/Rockies this week, with the
next influx of moisture from Mexico possible early next week.
Scattered to numerous showers and thunderstorms are expected with
heavy rainfall and localized flash flooding potentials. Sensitive
places such as burn scars, steep terrain, etc. would be the most
vulnerable to possible flooding concerns. WPC Excessive Rainfall
Outlook (ERO) Marginal Risks are now in place through the weekend.

Elsewhere, convection with enhanced heavy rains are forecast to
linger over the Southeast through Saturday given support aloft and
slow/wavy frontal progression, with additional activity back
through the Southern Appalachians/Tennessee Valley as covered by an
ERO Marginal Risk area. Ample subsequent northern stream system
energies set to dig into the upper trough position over the East
should support organized enhanced to heavy convective rainfall
potential from the Great Lakes/Ohio Valley this weekend through the
Eastern Seaboard through early-mid next week.

Persistent upper troughing and embedded moisture feed offers mid-
summer weekend light rain chances to clip the Pacific Northwest.


Kebede/Schichtel


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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