091
FXUS21 KWNC 231818
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT July 23 2026

SYNOPSIS: Strong mid-level high pressure is forecast to shift westward by the
end of July, leading to an expanding heat wave across the West. Antecedent
dryness along with the likelihood of above-normal temperatures and below-normal
precipitation during the next two weeks supports an increased risk for the
rapid onset of drought to parts of the Great Plains and Corn Belt. The East
Pacific is likely to remain active with additional tropical cyclone development
favored and combined with the ongoing/predicted heat wave, a renewal of an
enhanced Monsoon is expected during the first week of August.

HAZARDS

High risk of extreme heat for portions of Louisiana and Texas, Fri, Jul 31.

High risk of extreme heat for portions of the Southwest, Great Basin, and
California, Fri-Sat, Jul 31-Aug 1.

Moderate risk of extreme heat for much of the SouthernPlains, Lower Mississippi
Valley, Rockies, Great Basin, California, and the Southwest, Fri-Sun, Jul
31-Aug 2.

Slight risk of extreme heat for many parts of the western two-thirds of the
CONUS and Southeast U.S., Fri-Thu, Jul 31-Aug 6.

Slight risk of heavy precipitation for parts of the Southeast, Fri-Sun, Jul
31-Aug 2.

Slight risk of heavy precipitation for parts of the Desert Southwest, Sun-Thu,
Aug 2-6.

Rapid onset drought (ROD) possible for parts of the Great Plains and Corn Belt.

DETAILED SUMMARY

FOR SUNDAY JULY 26 - THURSDAY JULY 30:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR FRIDAY JULY 31 - THURSDAY AUGUST 06: The GEFS and ECENS are in good
agreement and remain consistent that an amplified 500-hPa ridge becomes
centered from California and the Desert Southwest northeast to the Northern
High Plains from Jul 31 to Aug 2. This ridge peaks in strength on July 31 when
500-hPa heights reach 597-598 dm over the Four Corners with 594 dm heights
extending as far north as Montana. This anomalous mid-level ridge continues to
support a moderate to high risk of extreme heat throughout a large area of the
western and south-central Contiguous U.S. (CONUS) through the beginning of
August. Since late July to the beginning of August is the hottest time of year,
the Week-2 Hazards used the calibrated ECMWF heat tool as a guide on defining
risk levels spatially. The GEFS and ECENS Probabilitistic Extremes Tools (PETs)
were also used but relied on mostly for timing. A high risk of extreme heat is
posted for portions of the south-central and western CONUS where the calibrated
ECMWF heat tool depicts near or more than a 50% chance that either the heat
index or temperature exceeds the 90th percentile. Heat index values may reach
110F in the more humid areas of Louisiana and Texas. Maximum temperatures may
exceed 115F in the Desert Southwest, while the Central Valley of California
heats up to near 105F. The high risk in the south-central CONUS times off after
Jul 31 as the hot ridge retrogrades, but it continues through Aug 1 for parts
of the western CONUS. A moderate risk, valid Jul 31-Aug 2, extends farther
north to cover the Great Basin and Northern Intermountain West. Beyond the
early part of week-2, forecast uncertainty increases with the GEFS and ECENS
ensemble members diverging on the placement of the amplified 500-hPa ridge axis
over western North America. There is also a large ensemble spread on the
amplitude of the eastern CONUS trough with even minor support for an amplified
mid-level ridge developing. Despite this large ensemble spread, the PETs,
calibrated ECMWF heat index tool, and uncalibrated GEFS/ECENS temperature
anomalies justify a slight risk of extreme for the western two-thirds of the
CONUS through the entirety of week-2.



According to the U.S. Drought Monitor valid July 21, abnormal dryness (D0) and
moderate drought (D1) expanded this past week across the Dakotas where Rapid
Onset Drought (ROD) is well underway. Increasing 30-day precipitation deficits,
high evapotranspiration rates, and the increased chance of above-normal
temperatures and below-normal precipitation during the next two weeks support
an enhanced risk of ROD across even more of the Great Plains and Corn Belt.



As of 11am PDT on Jul 23, the National Hurricane Center (NHC) states that there
is a 70 (90)% chance of TC development across the East Pacific during the next
48 hours (7 days). The GFS and ECMWF models are in good agreement that this
potential TC would track northwestward, favoring a moisture surge from the Gulf
of California north into the Desert Southwest. As the 500-hPa ridge axis shifts
northward, there would be an increasing chance of an enhanced Monsoon.
Beginning on Aug 2, a slight risk of heavy precipitation is posted for the
Desert Southwest where the PETs generally depict 3-day precipitation amounts
exceeding the 85th percentile and 0.5 inch.



A front is expected to become stationary from the coastal Carolinas southwest
to the Florida Panhandle later next week. This front may enhance convection and
the ECMWF PET supports maintaining a slight risk of heavy precipitation for
parts of the Southeast from Jul 31 to Aug 2.

FORECASTER: Brad Pugh

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