Valid Tuesday July 28, 2026 to Monday August 03, 2026
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM
EDT July 20 2026
Synopsis: Persistent mid-level high pressure is
expected to bring an elevated risk of extreme heat to a large portion of the
contiguous U.S. (CONUS) from the Ohio and Tennessee Valleys and Southeast
westward to the West. Hot weather and near or below normal rainfall bring an
increased risk of rapid onset drought to part of the northern Great Plains. In
the West, the monsoonal circulation may be periodically robust with localized
enhanced rainfall, but due to high uncertainty no associated precipitation
hazard is designated at this time. One or more tropical cyclones might also
impact Hawaii, raising the potential for heavy precipitation and gusty winds.
Meanwhile, development of a surface low east of the Appalachians and associated
wavering frontal boundary across the southeastern CONUS and southern
Mid-Atlantic supports a heavy precipitation risk for these regions until the
middle of week-2. A tight pressure gradient from surface high pressure over the
Northeast Pacific and adjacent low pressure over California may support
episodic high winds across coastal parts of southwest Oregon and northern
California.
Hazards - Moderate risk of extreme heat for
much of the Great Plains and adjacent parts of the Mississippi Valley, and the
Southwest, Tue-Thu, Jul 28-30.
- Slight risk of extreme heat for many parts of the Gulf Coast and Florida,
Ohio and Tennessee, and Mississippi Valleys, Great Plains, Central and Southern
Rockies, Great Basin, Southwest, and California Valley, Tue-Mon, Jul 28-Aug 3.
- Slight risk of heavy precipitation for the central Gulf Coast, part of the
South Atlantic region, and the eastern Carolinas, Tue-Thu, Jul 28-30.
- Slight risk of high winds for coastal portions of southwestern Oregon and
northern California, Tue-Sun, Jul 28-Aug 2.
- Rapid onset drought (ROD) possible for part of the northern Great Plains.
Detailed SummaryFor Thursday July 23 - Monday July 27:
WPC
Days 3-7 U.S. Hazards For Tuesday July 28 - Monday
August 03: Models continue to be in good agreement featuring a persistent
amplified 500-hPa ridging over the western and central CONUS and troughing
across the northwestern and northeastern regions. Ridging is generally more
amplified across the models compared to yesterday, centered over the Four
Corners region and expanding westward with time. This feature favors an
increased risk of extreme heat across large parts of the western, central, and
southern CONUS. Both northwest and northeast of this broad area, stagnant
mid-level troughs are expected to slowly weaken but remain essentially
stationary through the period, likely keeping extreme heat out of these regions.
Underneath the ridging aloft, an elevated potential for heat risk continues
to be supported by a number of temperature and heat tools across many parts of
the southern, western, and central CONUS. Higher than normal dewpoints are also
favored east of the Rockies due to a long fetch of Gulf moisture near the
surface, increasing dew points and helping to drive up heat index values there.
A moderate risk of extreme heat is posted for Jul 28-30, with coverage expanded
to include more of Arizona and the Great Plains. These adjustments are based
mainly on increased heat signals primarily in the GEFS Probabilistic Extreme
Tool (PET). The ECENS PET probabilities may be lower due to forecast potential
for localized heavy rainfall across the Four Corners due to the Southwest
Monsoon. Deep South Texas and part of the Desert Southwest have significant
chances for heat index values or absolute temperatures to top 110 deg F, but
this is not as unusual there as it is in the locations farther north.
Surrounding the moderate risk area, a large slight risk of extreme heat remains
posted throughout week-2, with slight expansion eastward into parts of the
Great Lakes region and Ohio Valley. Anomalously high SSTs in the waters
adjacent to the Gulf and South Atlantic coasts are expected to contribute to
heat and humidity east of the Rockies. According to the National Blend of
Models (NBM), southern portions of the heat risk area such as the Southwest,
Southern Plains, Lower MIssissippi Valley and Florida may experience near or
record breaking high nighttime temperatures in the upper 70s to low 80s, which
would provide little overnight relief. In general the ECENS PET is not as
robust with the odds for extreme heat compared to the GEFS across the West but
has increased probabilities for heat across the Southern Plains and Lower
Mississippi Valley.
Meanwhile, antecedent dryness, anomalous warmth and dryness during week-1,
and the potential for extreme heat during week-2 support an enhanced risk of
Rapid Onset Drought (ROD) across portions of the Northern Plains. The
anticipated heat is expected to overwhelm any short-lived relief that may occur.
Week-2 is expected to be an active period of tropical activity in the
eastern Pacific. More than one tropical cyclone is expected, and models have
consistently shown at least one of these systems moving far enough toward the
central Pacific to threaten Hawaii with heavy rain and high winds. Please refer
to the National Hurricane Center (NHC) for the latest tropical developments.
Despite the strong mid-level ridge favored across the western CONUS, the
forecast position of the ridge center does not support an extreme advection of
monsoonal moisture into the region, although model forecasts and the PETs today
show slightly higher likelihood than yesterday. In addition, it is possible
that one or more of the tropical cyclones expected in the eastern Pacific could
track northward and contribute to a surge of tropical moisture into the region,
which would significantly enhance rainfall amounts. Raw model output and the
PETs aren't sufficiently robust to support any slight heavy precipitation risk
from being posted, but with the tools trending wetter and the potential for
tropical moisture incursion, the situation will need to be closely monitored.
Multiple models indicate possible surface low pressure initially over the
Ohio Valley redeveloping east of the Appalachians by the beginning of week-2
with an associated wavering frontal boundary forming near the central Gulf and
South Atlantic coastal regions in conjunction with the mid-level troughing
favored over the eastern U.S. This pattern supports slight risk of heavy
precipitation to parts of the central Gulf Coast, South Atlantic region, and
eastern Carolinas, Jul 28-30. There is uncertainty about how much rainfall
occurs over the land versus offshore, thus only a slight risk is designated.
There is currently limited threat of flooding across the eastern Carolinas
designated for week-1, thus heavy rainfall could support localized flooding.
The ECENS PET and uncalibrated ensemble output is more favorable of heavy
rainfall occurring over land compared to the GEFS, indicating at least a 20%
chance of 3-day rainfall exceeding the 85th percentile climatologically and one
inch.
Across the West, surface high pressure over the northeastern Pacific and
adjacent surface low pressure over California and the Great Basin may support a
tight pressure gradient across parts of the West Coast. Thus a slight risk of
high winds is highlighted for coastal portions of southwestern Oregon and
northern California, Jul 28-Aug 2.
Forecaster: Melissa Ou
$$
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.
Resources
Week-2 Probabilistic Extremes Tool
GFS Ensemble Forecasts
www.nws.noaa.gov
