Weather Prediction Center

National Oceanic and Atmospheric Administration

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
220 AM EDT Mon Aug 24 2026

Valid 12Z Mon Aug 24 2026 - 12Z Wed Aug 26 2026

...Hazardous record-breaking heat continues across the south-central U.S.
into the Southwest this week...

...Flash flooding and severe weather threat across portions of the
Southwest and into the Rockies/Plains, Upper Midwest, and Southeast
through Tuesday...


A strong ridge anchored over the Southwest and south-central U.S. will
continue to bring hazardous heat across the Southern Plains and Lower
Mississippi Valley, and gradually into the Southwest by mid-week. Daytime
highs will reach 100-110 degrees across the southern Plains, while
portions of the Southwest can reach up to 115. Some areas are even
expected to break dozens of high/low daily temperatures through the week.
With the combination of well above normal temperatures and the high
humidity, heat indices will remain elevated. Additionally, the warm
overnight temperatures will provide limited recovery, leading to
widespread Major to Extreme HeatRisk through the week. See the latest Key
Messages linked at the bottom of the discussion for more information.

The western periphery of the ridge will remain a corridor for monsoonal
moisture extending northward across the Four Corners and Intermountain
West/Rockies. Unstable airmass will interact with shortwave energy and the
frontal boundary, leading to scattered thunderstorms across portions of
the Southwest, Great Basin, and central Rockies. The strongest storms will
be capable of producing severe thunderstorms with gusty winds and flash
flooding through Tuesday, especially over areas that have sufficient
instability. Further north, a progressive westerly flow will persist
across the northern Rockies/Plains and upper Midwest. As the frontal
boundary moves eastward, it will interact with warm unstable air,
supporting repeated organized showers and thunderstorms across the
Rockies/Plains into the Upper Midwest. Locally heavy rainfall and severe
thunderstorms will be possible with stronger storms through Tuesday,
especially over the central/southern High Plains.

Meanwhile, the surface low and associated frontal boundary will continue
to exit eastward from the Northeast, but shortwave troughs will continue
to produce lingering showers and thunderstorms through Monday across the
Lower Great Lakes and New England. Further south, the trailing frontal
boundary will drape across the Southeast into the southern Plains,
bringing chances for showers and thunderstorms through Tuesday. As the
boundary interacts with warm moist air and sufficient instability,
organized storm cells may develop. The strongest storms may produce
damaging winds, severe thunderstorms, and localized flash
flooding/excessive rainfall, especially along the Gulf Coast, Lower
Mississippi Valley, and Southeast Coast.



Oudit


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php

Extreme Heat Key Messages available at:
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
328 AM EDT Mon Aug 24 2026

Valid 12Z Thu Aug 27 2026 - 12Z Mon Aug 31 2026


...Hazardous Heat continues from the Desert Southwest to the
Southern Plains...

...Overview...

The upper level pattern will feature troughing in the Northwest and
East with a strong ridge anchored over the Southwest. The ridge
will flatten late this week as upper level troughing strengthens
over the Northwest, resulting in some areas seeing relief from the
ongoing heat wave, but hazardous heat will persist for the Desert
Southwest and southern Plains. Moisture on the western periphery of
the ridge will continue to support daily monsoonal convection
across the Intermountain West. Meanwhile, several frontal systems
will push through the upper troughs, bringing showers/thunderstorms
from the northern/central Plains to the East/Southeast U.S..

...Guidance/Predictability Assessment...

Guidance agrees that an ongoing upper pattern highlighted by a
strong Southwest U.S. to southern Plains high/ridge anchored by
mean troughs near the Pacific Northwest and the east-central U.S.
will persist over the next week. This will continue to support a
protracted heatwave with Hazardous Heat threats from the South-
Central to Southwest U.S.. Along the ridge's periphery monsoonal
moisture may promote scattered convection from the Southwest to the
Rockies, with convection also working into the north-central U.S..
Shortwaves will maintain upper troughing over the east-central
U.S. to favor wavy and temperature moderating frontal surges.
Expect unseasonally well organized rain/thunderstorms daily as
wavy fronts push into and stall over the East/Southeast and pool
deep moisture and instability.

A broad model/ensemble mean and machine learning guidance blend
seems to provide a solid forecast basis with good product and
messaging continuity given favorable clustering trends that have
further improved with the latest 00 UTC guidance.

...Weather/Hazards Highlights...

Still under the influence of the upper high/ridge, daily maximum
temperatures across the southern Plains will continue to rise into
the 90s and 100s with oppressive heat indices. Record- breaking
warm overnight temperatures across the southern tier will further
limit recovery from the heat, especially given heatwave longevity
which may result in heat related illnesses. Conditions will improve
this week for the Lower Mississippi Valley, but widespread Major
to Extreme HeatRisk will persist in the southern Plains. For the
Desert Southwest, daytime max temperatures are forecast to soar
into the 110s, which will create heat concerns this week. Pre-
frontal areas of the Southeast may be a few degrees above normal,
but forecast precipitation and cloud cover will help keep heat in
check. Please see WPC's Key Messages for more extreme heat details.

Monsoonal moisture streaming northward on the periphery of the
upper ridge will fuel scattered, diurnally driven convection from
the Southwest to the Rockies. Individual cells may lead to isolated
instances of flash flooding for sensitive locations such as burn
scars, favored terrain like slot canyons, and urban areas. There is
a Marginal Risk for parts of these areas in the WPC Day 4/Thursday
and Day 5 Friday Excessive Rainfall Outlooks (EROs).

Shortwaves rounding the top of the ridge to the east-central U.S.
mean upper trough will periodically trigger showers and some strong
thunderstorms from the northern and central Plains to the Midwest
this week. A Marginal Risk ERO covers this threat. Downstream,
elongated ERO Marginal Risk areas are highlighted for portions of
the Southeast and Mid-Atlantic that may see repeated rounds of
locally heavy precipitation as wavy frontal boundaries approach and
ultimately stall over these regions.

Later period, a stronger frontal system will push across an
unsettled Northwest and north-Central U.S., bringing increasing
precipitation chances and potentially heavy rainfall to the Plains
and Midwest. Warm, southerly flow on the southern side of the
system may increase heat for the south-central U.S. next weekend.


Schichtel


Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast, excessive rainfall outlook,
winter weather outlook probabilities, heat indices and Key Messages
are at:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
247 AM EDT Mon Aug 24 2026

Valid 00Z Tue 25 Aug 2026 - 00Z Tue 01 Sep 2026

...Tropical Depression Moke passing south of the Islands...

Passage today of Tropical Depression Moke several hundred miles
to the south of the islands favors lingering strong gusty winds
over the state within tightened pressure gradients between surface
high pressure north of the state. A deep plume of moisture north
of Moke will fuel additional rainfall. With Moke rains coming
quickly on the heels of Lala, life-threatening flooding and
mudslides remain a concern. Even as the system continues west and
weakens, guidance shows an elongated stretch of deeper moisture
may remain across the islands, potentially yielding local
downpours into Tuesday. Guidance agrees to show drier conditions
with a return to more typical easterly trades with a limited
windward terrain focusing showers pattern the rest of the week.

Schichtel

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
417 AM EDT Mon Aug 24 2026
Day 1
Valid 12Z Mon Aug 24 2026 - 12Z Tue Aug 25 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ALONG THE GULF
COAST FROM SOUTHEASTERN LOUISIANA TO SOUTHERN ALABAMA...

...Ozarks-Lower Mississippi Valley and Central Gulf Coast to the
Coastal Carolinas...

Elevated storms are expected to develop later this morning and
propagate southeast from northern Arkansas into the lower
Mississippi Valley mid to late morning. Following an expected
decrease in activity, storms are forecast to re-intensify in the
afternoon, with the consensus of the CAMs showing surface based
storms organizing over portions of southeastern Louisiana, southern
Mississippi, and perhaps as far east as southern Alabama.
Shortwave energy dropping into the region will likely interact with
a pool of deepening moisture, with PWs increasing to over 2.25
inches according to recent RAP runs. This will support very heavy
rates with localized heavy accumulations likely. A Slight Risk was
introduced where both the HREF and REFS indicate localized totals
over 3 inches are likely. While the antecedent conditions are dry,
both the HREF and REFS show probabilities for amounts exceeding
3-hr FFGs nearing 30 percent across portions of the highlighted
region during the late afternoon-early evening hours -- with
urbanized and poor drainage areas likely to be the most susceptible
to flash flooding.

Further east through northern Florida and along the Southeast Coast
to the Carolinas, a ribbon of deep moisture (PWs 1.75-2+ inches)
centered along and south of a slow-moving boundary will support
enhanced diurnal activity, with developing storms likely to produce
localized heavy rainfall rates and amounts. A Marginal Risk was
maintained where both the HREF and REFS show high probabilities for
amounts over 2 inches.

...Southwest to the Central High Plains...

With not much change to the overall pattern, and the development of
monsoon-moisture-fueled storms expected to continue, maintained a
Marginal Risk covering much of the same area as previous day --
extending from portions of the Southwest northward into the Great
Basin and northern Rockies, and east into the central Rockies and
High Plains.

Pereira


Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
417 AM EDT Mon Aug 24 2026
Day 2
Valid 12Z Tue Aug 25 2026 - 12Z Wed Aug 26 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE SOUTHWEST AND ROCKIES TO THE CENTRAL PLAINS AND ALONG THE GULF
AND SOUTHEAST COASTS...

...Southwest to the Central Plains...

Diurnal shower and thunderstorms activity will develop once again
across portions of the Southwest into the central and southern
Rockies. However, the footprint for these storms will likely be
less than earlier in the week as the upper high begins to shift
west -- capping or directing moisture away from parts of the
Southwest and Great Basin. Therefore, continued to leave southern
Arizona and New Mexico and much of the Great Basin out of the
Marginal Risk.

The models continue to signal a chance for organized storms and
potentially heavy amounts across portions of the central Plains.
Energy emanating from the West and sliding off of the top of the
western U.S. ridge is expected to interact with an area of
increasing moisture that will be deepening ahead of cold front
dropping through the central U.S. While models continue to differ
on the details, they have presented a stronger signal for organized
activity over portions of southern Nebraska into Kansas. But given
the uncertainty and what are expected to be fairly progressive
storms, maintained just a Marginal Risk for now.

...Gulf and Southeast Coasts...

Another day of potentially heavy diurnal showers and storms are
expected from portions of the Florida Panhandle to coastal South
Carolina. PWs are forecast to remain at or above 1.75 inches,
fueling efficient-rainfall-producing-storms. Farther west, the
consensus of the guidance shows much of the heavier activity
developing and remaining offshore with a weak wave. There is some
potential for heavy amounts developing onshore, but at this point
they look to be mostly confined to the immediate coast of
southeastern Louisiana, where flash flooding is not a typical
concern.

Pereira


Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
417 AM EDT Mon Aug 24 2026
Day 3
Valid 12Z Wed Aug 26 2026 - 12Z Thu Aug 27 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE SOUTHWEST, ROCKIES, AND CENTRAL SOUTHERN HIGH PLAINS AND FROM
PARTS OF THE LOWER MISSISSIPPI TO THE TENNESSEE VALLEY...

...Lower Mississippi Valley to the Tennessee Valley...

A series of shortwaves sliding off of the western U.S. ridge and
then along the base of a trough amplifying over the eastern U.S.
are expected to generate showers and storms across portions of the
region. While the models differ greatly on the details, there is
some general indication that one of the more defined waves moving
across the region will help develop organized storms and some
greater potential for heavy accumulations over parts of the lower
Mississippi Valley. Backing flow and deepening moisture may also
support heavy rainfall developing farther east into parts of the
Tennessee Valley, but model spread is significant there as well --
limiting forecast confidence.

...Southwest and Rockies to the Central and Southern High Plains...

Overall, not much change from the previous day with diurnal
activity likely to be very limited across southern Arizona and New
Mexico and the Great Basin. Farther east, storms that develop
along the eastern front of the Rockies are expected to propagate
more south than the previous day and remain mostly limited to the
High Plains. With the ridge shifting west, expect to see some
return of deeper moisture and convective activity over a greater
portion of the southern Rockies and High Plains this period.

Pereira

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
417 AM EDT Mon Aug 24 2026
Day 4 and Day 5
Valid 12Z Thu Aug 27 2026 - 12Z Sat Aug 29 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM PORTIONS OF
THE SOUTHWEST AND INTERMOUNTAIN WEST AS WELL AS PARTS OF THE
SOUTHEAST AND MID ATLANTIC...

...Southwest and Intermountain West to Central and Southern Plains...

Maintained a Marginal Risk both days across portions of the
Southwestern US as monsoonal moisture fuels diurnally driven
widely scattered convection covering portions of Arizona and New
Mexico. Given the plume of precipitable water values nosing back
into to the Arizona desert on the western side of a broad mid- and
upper level high...local downpours leading to instances of flash
flooding are possible.

Farther north...deep moisture and weak shortwave energy riding
around the ridge axis associated with the upper high will combine
with southerly flow of deep moisture in low-levels to the lee of
the Front Range to support more showers and thunderstorms capable
of producing heavy rainfall rates and flash flooding. Locally heavy
rainfall rates may lead to isolated instances of flash flooding
here as well.

...Southeast to Mid-Atlantic Region/Southern New England Coast...

Showers and thunderstorms capable of producing heavy to excessive
rainfall each day should be focused along a quasi-stationary front
extending over the Southeast US/Gulf coast region into parts of the
Mid Atlantic. Height falls associated with weak shortwave energy
will embedded within a broader trough will aid and focus the
convection in vicinity of the front.

In addition...the approach of a front in the northern stream trough
will tap into some deeper moisture being drawn northward ahead of
the above-mentioned front to bring an isolated threat of flooding
on Thursday before the northern stream front sweeps off shore later
in the Day 4 period.

...Upper Midwest/Northern Plains...
There is a risk of excessive rainfall developing across parts of
the Upper Midwest/Northern Plains on Friday as low level flow of
Gulf moisture is drawn into the region on 30 to 45 kt low level
jet and rides over a surface warm front over the region.

Bann

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
417 AM EDT Mon Aug 24 2026
Day 4 and Day 5
Valid 12Z Thu Aug 27 2026 - 12Z Sat Aug 29 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM PORTIONS OF
THE SOUTHWEST AND INTERMOUNTAIN WEST AS WELL AS PARTS OF THE
SOUTHEAST AND MID ATLANTIC...

...Southwest and Intermountain West to Central and Southern Plains...

Maintained a Marginal Risk both days across portions of the
Southwestern US as monsoonal moisture fuels diurnally driven
widely scattered convection covering portions of Arizona and New
Mexico. Given the plume of precipitable water values nosing back
into to the Arizona desert on the western side of a broad mid- and
upper level high...local downpours leading to instances of flash
flooding are possible.

Farther north...deep moisture and weak shortwave energy riding
around the ridge axis associated with the upper high will combine
with southerly flow of deep moisture in low-levels to the lee of
the Front Range to support more showers and thunderstorms capable
of producing heavy rainfall rates and flash flooding. Locally heavy
rainfall rates may lead to isolated instances of flash flooding
here as well.

...Southeast to Mid-Atlantic Region/Southern New England Coast...

Showers and thunderstorms capable of producing heavy to excessive
rainfall each day should be focused along a quasi-stationary front
extending over the Southeast US/Gulf coast region into parts of the
Mid Atlantic. Height falls associated with weak shortwave energy
will embedded within a broader trough will aid and focus the
convection in vicinity of the front.

In addition...the approach of a front in the northern stream trough
will tap into some deeper moisture being drawn northward ahead of
the above-mentioned front to bring an isolated threat of flooding
on Thursday before the northern stream front sweeps off shore later
in the Day 4 period.

...Upper Midwest/Northern Plains...
There is a risk of excessive rainfall developing across parts of
the Upper Midwest/Northern Plains on Friday as low level flow of
Gulf moisture is drawn into the region on 30 to 45 kt low level
jet and rides over a surface warm front over the region.

Bann

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
154 PM EDT Wed May 6 2026

Valid 00Z Thu May 07 2026 - 00Z Sun May 10 2026

...WPC Winter Weather Desk no longer routinely staffed until
late September, 2026...

Pending any significant winter weather, the WPC Winter Weather Desk
will not be staffed through the summer. The desk will resume
continuous staffing starting in the fall.

The WPC winter products will continue to be produced, however, and
all products except the heavy snow discussion (HSD) will be
available. This includes the Winter Storm Outlook (WSO), Winter
Storm Severity Index (WSSI), and Probabilistic Winter Precipitation
Forecasts (PWPF).


WPC

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
328 AM EDT Mon Aug 24 2026

Valid 12Z Thu Aug 27 2026 - 12Z Mon Aug 31 2026


...Hazardous Heat continues from the Desert Southwest to the
Southern Plains...

...Overview...

The upper level pattern will feature troughing in the Northwest and
East with a strong ridge anchored over the Southwest. The ridge
will flatten late this week as upper level troughing strengthens
over the Northwest, resulting in some areas seeing relief from the
ongoing heat wave, but hazardous heat will persist for the Desert
Southwest and southern Plains. Moisture on the western periphery of
the ridge will continue to support daily monsoonal convection
across the Intermountain West. Meanwhile, several frontal systems
will push through the upper troughs, bringing showers/thunderstorms
from the northern/central Plains to the East/Southeast U.S..

...Guidance/Predictability Assessment...

Guidance agrees that an ongoing upper pattern highlighted by a
strong Southwest U.S. to southern Plains high/ridge anchored by
mean troughs near the Pacific Northwest and the east-central U.S.
will persist over the next week. This will continue to support a
protracted heatwave with Hazardous Heat threats from the South-
Central to Southwest U.S.. Along the ridge's periphery monsoonal
moisture may promote scattered convection from the Southwest to the
Rockies, with convection also working into the north-central U.S..
Shortwaves will maintain upper troughing over the east-central
U.S. to favor wavy and temperature moderating frontal surges.
Expect unseasonally well organized rain/thunderstorms daily as
wavy fronts push into and stall over the East/Southeast and pool
deep moisture and instability.

A broad model/ensemble mean and machine learning guidance blend
seems to provide a solid forecast basis with good product and
messaging continuity given favorable clustering trends that have
further improved with the latest 00 UTC guidance.

...Weather/Hazards Highlights...

Still under the influence of the upper high/ridge, daily maximum
temperatures across the southern Plains will continue to rise into
the 90s and 100s with oppressive heat indices. Record- breaking
warm overnight temperatures across the southern tier will further
limit recovery from the heat, especially given heatwave longevity
which may result in heat related illnesses. Conditions will improve
this week for the Lower Mississippi Valley, but widespread Major
to Extreme HeatRisk will persist in the southern Plains. For the
Desert Southwest, daytime max temperatures are forecast to soar
into the 110s, which will create heat concerns this week. Pre-
frontal areas of the Southeast may be a few degrees above normal,
but forecast precipitation and cloud cover will help keep heat in
check. Please see WPC's Key Messages for more extreme heat details.

Monsoonal moisture streaming northward on the periphery of the
upper ridge will fuel scattered, diurnally driven convection from
the Southwest to the Rockies. Individual cells may lead to isolated
instances of flash flooding for sensitive locations such as burn
scars, favored terrain like slot canyons, and urban areas. There is
a Marginal Risk for parts of these areas in the WPC Day 4/Thursday
and Day 5 Friday Excessive Rainfall Outlooks (EROs).

Shortwaves rounding the top of the ridge to the east-central U.S.
mean upper trough will periodically trigger showers and some strong
thunderstorms from the northern and central Plains to the Midwest
this week. A Marginal Risk ERO covers this threat. Downstream,
elongated ERO Marginal Risk areas are highlighted for portions of
the Southeast and Mid-Atlantic that may see repeated rounds of
locally heavy precipitation as wavy frontal boundaries approach and
ultimately stall over these regions.

Later period, a stronger frontal system will push across an
unsettled Northwest and north-Central U.S., bringing increasing
precipitation chances and potentially heavy rainfall to the Plains
and Midwest. Warm, southerly flow on the southern side of the
system may increase heat for the south-central U.S. next weekend.


Schichtel


Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast, excessive rainfall outlook,
winter weather outlook probabilities, heat indices and Key Messages
are at:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw