950
FXUS21 KWNC 111823
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT July 11 2025

SYNOPSIS: Mid-level high pressure is forecast across much of the contiguous
U.S. (CONUS) during the week-2 period. However, anomalies are forecast to be
relatively weak early in the period, even for the summer months when mid-level
anomalies are generally reduced. Mid-level high pressure begins to increase
across the western Gulf Coast and Lower Mississippi Valley by the middle of the
period, increasing chances for extreme heat in these regions. Chances for heavy
precipitation are increased across the southern Atlantic States and Central and
Eastern Gulf Coast due to a stalled frontal boundary. In the Midwest, a warm
front moving through the region may increase chances for a period of heavy
precipitation.

HAZARDS

Slight risk of heavy precipitation for portions of the Gulf Coast, Southeast,
and Mid-Atlantic, Sat-Tue, Jul 19-22.

Slight risk of heavy precipitation for portions of the Upper and Middle
Mississippi Valley and upper Great Lakes, Sat-Mon, Jul 19-21.

Slight risk of extreme heat for portions of the Southern Plains and Lower
Mississippi Valley, Mon-Wed, Jul 21-23.

Slight risk of extreme heat for portions of the Pacific Northwest and Northern
Intermountain, Wed-Fri, Jul 23-25.

DETAILED SUMMARY

FOR MONDAY JULY 14 - FRIDAY JULY 18:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR SATURDAY JULY 19 - FRIDAY JULY 25: A stationary frontal boundary is
forecast for the Mid-Atlantic, Southeast, and Gulf Coast that is likely to
continue to promote increased chances for enhanced precipitation across these
regions through much of the week-2 period. Therefore, a slight risk of heavy
precipitation is posted for Jul 19-22 for the Mid-Atlantic, Southeast and Gulf
Coast. The Probabilistic Extremes Tools (PETs) from the GEFS and ECENS indicate
20-30% chances for 3-day precipitation amounts exceeding the 85th
climatological percentile and 1 inch across the highlighted region. Tropical
moisture may interact with the frontal boundary increasing the available
atmospheric moisture. This is highlighted in the raw ensemble standardized
Precipitatable Water Anomalies (PWATs) being substantially above normal for
this time of year across the region. The precipitation is likely to be
convective in nature and this can sometimes be smoothed by the ensemble
guidance, thus localized amounts of precipitation may be higher. Many of the
areas in the highlighted slight risk have seen a very wet late spring and early
summer further increasing the risk of heavy precipitation.



A warm front lifting through the Middle and Upper Mississippi Valley and Great
Lakes may bring increased chances for heavy precipitation early in the period
across the region. The ECENS PET shows at least a 20% chance of this region
exceeding the 85th percentile and 0.75 inches of precipitation. The raw
ensemble guidance from the GEFS, ECENS, and ECENS-AIFS are in agreement
highlighting this region. Precipitation observed in the past 7 days along with
forecast precipitation for week-1 may leave portions of this area vulnerable to
any additional precipitation early in week-2. Therefore, a slight risk of heavy
precipitation is posted for Jul 19-21 for this area.



Along the western Gulf Coast and Lower-Mississippi Valley, model guidance from
the ECENS and GEFS PETs have come into better agreement for increased chances
for a period of extreme heat. These tools indicate at least a 20% chance of
maximum temperatures exceeding the 85th percentile. Meanwhile, a short-term
bias-corrected heat-index tool indicates enhanced chances for apparent
temperatures approaching or exceeding 110 degF. A slight risk of extreme heat
is posted based on this guidance for Jul 21-23 for parts of southern and
eastern Texas and the Lower Mississippi Valley.



Later in week-2, the GEFS and ECENS indicate ridging developing across much of
the West. The ridge is forecast to be centered across the Four Corners region
and this would generally support conditions for an enhanced monsoon
circulation. However, model guidance continues to indicate very little
atmospheric moisture moving into the region with precipitable water anomalies
(PWAT) remaining near to below normal across the Southwest. Therefore, the
slight risk of heavy precipitation that has been in place in recent days is
discontinued but the area will continue to be monitored for increased signals
of moisture.



This area of positive 500-hPa height anomalies has also expanded across the
Northwest. PETs from the GEFS and ECENS indicate increasing chances for extreme
heat by the end of week-2 with chances exceeding 30% for maximum temperatures
above the 85th climatological percentile. Raw temperature guidance tools are
also elevated across much of the Northwest. Based on this, a slight risk of
extreme heat is posted for elevations of the Pacific Northwest, interior
Washington state and the Snake River Valley for Jul 23-25.

FORECASTER: Ryan Bolt

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