529
FXUS21 KWNC 181812
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT July 18 2025

SYNOPSIS: Mid-level high pressure is predicted across much of the contiguous
U.S. (CONUS) excluding the West Coast early week-2, amplifying into the
interior West as the week progresses. This translates to increased chances for
extreme heat for many areas east of the Rockies, and in the Southwest. Many of
these areas could experience heat index values exceeding triple digits (deg F),
with the heat threat waning in the Southeast after the first few days. Possible
surface low formation over the Gulf of America increases the likelihood for
heavy precipitation in part of the central Gulf Coast at the beginning of the
period. Around the periphery of the amplifying mid-level ridge, periods of
localized heavy showers and thunderstorms may affect areas from the northern
High Plains through the western Great Lakes Region through mid-week. A sharp
surface pressure gradient along part of the southern California coast is
expected to bring an elevated risk of high winds there until mid-week. Dry
soils and anticipated dry, hot conditions support a risk of Rapid Onset Drought
(ROD) over Kansas.

HAZARDS

High risk of extreme heat for portions of the Great Plains and Mississippi
Valley, Sat-Mon, Jul 26-28.

Moderate risk of extreme heat for parts of the Southeast, Sat-Sun, Jul 26-27.

Moderate risk of extreme heat for many areas from the High Plains to near the
Appalachians, Sat-Fri, Jul 26-Aug 1.

Slight risk of extreme heat for a large part of the central and southwestern
CONUS, Sat-Fri, Jul 26-Aug 1.

Slight risk of extreme heat in parts of the Southeast and Mid-Atlantic,
Sat-Mon, Jul 26-28.

Slight risk of heavy precipitation for the Central Gulf Coast, Fri-Sat, Jul
25-26.

Slight risk of heavy precipitation from the Northern Plains through the western
Great Lakes, Sat-Tue, Jul 26-29.

Rapid onset drought risk for parts of Kansas.

DETAILED SUMMARY

FOR MONDAY JULY 21 - FRIDAY JULY 25:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR SATURDAY JULY 26 - FRIDAY AUGUST 01: The GEFS, ECENS, and CMCE all show an
evolving mid-level pattern featuring a relatively flat mid-level ridge across
much of the CONUS from the Rockies eastward at the start of week-2. This
feature amplifies westward, peaking in strength over the central CONUS mid-week
before settling into the Rockies by the end of the period. Meanwhile, a
mid-level trough near the West Coast slowly deamplifies, and another mid-level
trough digs southward along the Eastern Seaboard. This pattern enhances the
risk of extreme heat for areas east of the Rockies and the Desert Southwest,
with the focus of extreme heat pushing westward with time. A high risk of
extreme heat (>60% chance) is designated for portions of the Middle and Lower
Mississippi Valley, and the central and southern Great Plains, Jul 26-28. A
broad area is highlighted with a moderate risk (40-60% chance) of extreme heat
for many areas from the Great Plains eastward through the Mississippi,
Tennessee, and lower Ohio Valleys throughout week-2. With high dewpoints
expected, heat index values are expected to exceed the 90th percentile compared
to climatology and triple digits deg F. Farther east, the heat risk wanes by
mid-week as the mid-level trough builds southward along the Eastern Seaboard. A
moderate risk of extreme heat is posted in parts of the Southeast Jul 26-27
while a slight risk extends northward across much of the Mid-Atlantic through
Jul 28. The National Blend of Models (NBM) show near record daytime
temperatures over the Tennessee Valley and near record nighttime temperatures
across many areas across the East.



Surface low formation is possible over the Gulf of America at the beginning of
week-2 that could support areas of heavy precipitation along the Gulf Coast. A
slight risk of heavy precipitation is posted for the central Gulf Coast, Jul
26-27. Guidance is not as bullish with this feature as yesterday, and the
Probabilistic Extremes Tools (PETs) no longer indicate a 20% chance of 3-day
rainfall exceeding the 85th percentile. The reduced heavy precipitation signal
in the guidance led to the removal of the increased flooding risk that had
covered the area.



Further north, shower and thunderstorm activity along the northern periphery of
the mid-level ridge could bring localized heavy rainfall to portions of the
north-central CONUS. The slight risk area has again expanded westward to
include the Northern Plains, Upper Mississippi Valley, and western Great Lakes
for Jul 26-29 before the mid-level ridge axis moves west of these areas.



The PETs all highlight at least a 20 percent chance for high winds above the
85th climatological percentile and 25 mph early week-2 along part of the
central and southern California coastline. This prompted the posting of a
slight risk of high winds along part of the southern California coastline until
mid-week. Thereafter, the PETs become less consistent with the placement and
intensity of potentially high winds, if any, so the slight risk ends at that
time.



Anomalous dry soils and expected hot, dry conditions supports a risk of Rapid
Onset Drought (ROD) for parts of Kansas.

FORECASTER: Rich Tinker

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