903
FXUS02 KWNH 160644
PREEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
244 AM EDT Wed Jul 16 2025

Valid 12Z Sat Jul 19 2025 - 12Z Wed Jul 23 2025

...Central Gulf Coast heavy rain threat may linger into Saturday...


...Overview...

The medium range period will continue to feature an expansive and
building upper ridge stretched across the southern U.S. and
progressive upper shortwaves moving through the northern tier
states. Convection will be plenty across much of the nation east of
the Rockies, but especially along a west to east oriented nearly
stationary frontal boundary draped from the Midwest to the central
Appalachians this weekend. Lingering tropical moisture along the
Gulf Coast may bring one more day of heavy rain threats on Saturday
before dissipation within a larger scale ridge. Meanwhile,
monsoonal moisture will be in place through at least this weekend
in the Four Corners states to the south- central High Plains. Upper
ridging from the southern Plains to the Southeast will promote
summer heat into next week.


...Guidance/Predictability Assessment...

Model guidance continues to advertise an overall progressive
synoptic pattern dominated by a strengthening subtropical ridge
across the southern U.S. and a fairly fast moving jet and wave
train across the north. Model agreement remains reasonable for most
of the medium range period, aside from the typical small scale
differences in timing and amplitude of individual shortwaves. Some
additional uncertainty about how strong the southern ridge will be
and also reinforcing energy out West. The WPC forecast for tonight
used a blend of the deterministic guidance the first half of the
period, trending towards majority ensemble means (with smaller
proportions of the ECMWF) the latter half.


...Weather/Hazards Highlights...

The National Hurricane Center continues to monitor the potential
for tropical system development across the northern Gulf in the
short range period. The remnants of this energy (regardless of
development) may linger into next weekend, and could bring locally
heavy to excessive rainfall into at least Saturday. Despite the
relatively light QPFs forecast by the models, continued to maintain
a small slight risk across western Louisiana given the available
anomalous moisture and the forecasted heavy rains in the short
range.

A series of shortwaves and associated surface fronts through the
northern tier will continue to support showers and thunderstorms
from the northern Plains eastward to the Mid-Atlantic. This entire
area is encompassed by a broad marginal risk on the Excessive
Rainfall Outlooks with the warm and very moist airmass in place.
There is greater concern for training along a west to east oriented
nearly stationary boundary from the Midwest to the Central
Appalachians through the weekend, and a slight risk is in effect on
the Days 4 and 5 EROs for this region. Activity east of the
Rockies may overall shift east with a building ridge over the
Central U.S. but daily shower and thunderstorm threats will
continue into next week across the Great Lakes region and the East.

Farther south, ample monsoonal moisture will be in place across
the Southwest/Four Corners/southern Rockies region this weekend.
Marginal Risks remain across much of Arizona and New Mexico and
stretching into parts of Colorado and Utah. Areas like burn scars
and urban areas would be of greatest concern for flash flooding.
Monsoonal moisture may continue, but possibly slightly weaker, into
next week.

Temperatures in the High Plains to the northern/central Plains
looks to remain near or below normal (on the order of 5-10 degrees)
for this time of the year through much of the period, with some
moderation at times. Elsewhere, despite temperatures being only
modestly above normal, the persistence of ridging over the
Southeast will keep a moderate to major HeatRisk in place for the
region, with localized extreme impacts this weekend. This expands
westward into the Tennessee/Mississippi Valley and Central Plains
next week.


Santorelli


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 (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

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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