958
FXUS21 KWNC 141831
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT July 14 2026

SYNOPSIS: Persistent mid-level high pressure over the Four Corners occurring
near the peak of summer brings the risk of extreme heat for much of the central
and southeastern Contiguous U.S. (CONUS) as well as portions of the Interior
West throughout week-2. Increasing inflow of tropical moisture is favored to
enhance monsoon rains over the Desert Southwest throughout the forecast period.

HAZARDS

Moderate risk of extreme heat for much of East Texas and the Lower Mississippi
Valley, Wed-Fri, Jul 22-24.

Slight risk of extreme heat for much of the Southern Plains, Lower Mississippi
Valley, and Southeast U.S., as well as portions of the Central Plains and
Mid-Atlantic, Wed-Tue, Jul 22-28.

Slight risk of extreme heat for the Central Valley of California, Wed-Tue, Jul
22-28.

Slight risk of extreme heat for Interior Washington, Wed-Sun, Jul 22-26.

Moderate risk of heavy precipitation for much of the Central Rockies, Wed-Fri,
Jul 22-24.

Slight risk of heavy precipitation for much of the Desert Southwest and
southern Great Basin, Wed-Tue, Jul 22-28.

Rapid onset drought (ROD) possible for portions of the Dakotas.

DETAILED SUMMARY

FOR FRIDAY JULY 17 - TUESDAY JULY 21:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR WEDNESDAY JULY 22 - TUESDAY JULY 28: Multiple model ensembles depict
anomalous mid-level ridging persisting over the western CONUS throughout
week-2, with a closed 594-dm contour remaining near the Four Corners throughout
the forecast period. The ECMWF is becoming increasingly bullish on maintaining
this ridge as well as amplifying the subtropical ridge over the Caribbean,
thereby increasing the potential for extreme heat along the Gulf Coast.
Generally southerly flow off the Gulf of America is favored to boost dewpoints
east of the Rockies, resulting in potentially hazardous heat index values for
much of the Great Plains and along the Gulf Coast.



The potential for extreme heat continues to be supported by a variety of
forecast tools, and forecast confidence is higher today given an increased
signal strength relative to the past few days. The GEFS-ECWMF combined extreme
heat tool shows widespread 20% or greater chances (as high as 50% for portions
of the West) of either maximum temperatures or heat index values to exceed the
90th percentile at some point during the week-2 period for most of the CONUS
except along the Northern Tier. Additionally, probabilities exceed 40% and as
high as 60% for the same threshold across East Texas and the Lower Mississippi
Valley. When considered individually the two models disagree somewhat with
respect to regions affected and signal strength but have good agreement where
the signal is strongest. Given all this, a moderate risk of extreme heat is
posted for much of East Texas and the Lower Mississippi Valley covering Jul
22-24. A slight risk of extreme heat remains posted for the Central Valley of
California, as well as much of the southeastern and south-central CONUS, both
valid for all of week-2. A slight risk of extreme heat has also been added for
Interior Washington for Jul 22-26, consistent with increased signal from the
extreme heat tools. The persistent Four Corners ridge is favored to induce
anomalously warm temperatures well north into the Great Plains, although these
temperatures are less likely to reach hazardous thresholds. However, the
combination of anomalous warmth, near to below normal precipitation favored
during week-2, and antecedent dryness supports an enhanced risk of ROD across
portions of the Northern Plains.



Model ensembles are showing increased signal of enhanced precipitation stemming
from the southwestern monsoon. Dynamical models are depicting a potential
enhancement of monsoon convection through the middle of week-2, with
uncalibrated probabilities from the ECWMF and GEFS indicating widespread 50%
chances of 3-day precipitation totals to exceed half an inch, with some
locations seeing 20% chances of 1 inch accumulations along with higher
probabilities centered over the Central Rockies. The trend in increased monsoon
activity among model ensembles has been continuing for several days now, to
such an extent that a moderate risk of heavy precipitation has been added to
todays hazards outlook for portions of the Central Rockies valid Jul 22-24. A
slight risk of heavy precipitation remains valid for much of the Desert
Southwest and southern Great Basin and has been extended to cover all of the
week-2 period. This region is prone to flash flooding with relatively small
precipitation accumulations especially along dry creek beds and in canyons and
extreme caution should be exercised in such areas should thunderstorm activity
initiate nearby. Monsoonal thunderstorms can also produce dry lightning,
resulting in increased wildfire risk.

FORECASTER: Danny Barandiaran

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