Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
235 PM EDT Sat Jul 26 2025

...Dangerous heat wave persists in the Southeast through midweek
with gradual relief later week...

...Overview...

A large and strong upper high meandering over the central/southern
Plains into the Mid-South will cause a persistent and major heat
wave for those areas and especially into the Southeast through
midweek. Dangerous heat is forecast to extend north through the
Ohio Valley and Mid-Atlantic/Northeast Tuesday-Wednesday but
gradually get pressed southward behind a cold front as the week
progresses. Complexes of showers and storms are likely along the
northern periphery of the ridge -- across the northern/central High
Plains eastward into the Midwest. Scattered thunderstorms are
possible farther east at times, especially near the front as it
pushes southward and along a retrograding trough/low near the Gulf
Coast. Additionally, southerly flow will bring monsoonal moisture
into the Southwest states with possibly heavy rain.


...Guidance/Predictability Assessment...

Model agreement is excellent for the overall pattern through much
of next week. Models are unified in showing an expansive upper high
of 2+ standard deviations above normal, with widespread 594+ dm
500mb heights but with low chances of reaching 600 dm. Guidance
shows the high at its greatest expanse into Tuesday as it
encompasses the south-central Rockies eastward across the
Mississippi and Ohio Valleys and Southeast, before shrinking in
scope and being centered over the southern Plains by later next
week. Meanwhile the ridge axis will shift westward and build north
across the northern Rockies into western Canada starting Tuesday,
coincident with the upper trough edging into the north-central to
northeastern U.S. anchored by a large Hudson Bay to eastern Canada
upper low. Model differences were mostly negligible through the
period, considering the forecast horizon, and a general model blend
sufficed with only a minority weighting of the GEFS/ECMWF
ensembles by next Fri/Sat. This maintained very good continuity.

Regardless of the large scale agreement, shortwaves riding around
the ridge will cause more differences in sensible weather like
frontal placement, and convection will have further uncertainties
due to small boundaries like outflows interacting. These tend not
to become clearer until the short range or near term, so the
details of QPF remain uncertain, but at least the overall pattern
seems set.


...Weather/Hazards Highlights...

The persistent and strong upper ridge will lead to continued
dangerous heat that will be longest lasting across the Tennessee
Valley/Mid-South and Southeast into the Carolinas next week.
HeatRisk is in the Major (level 3/4) to Extreme (level 4/4)
categories for these areas through Wednesday or Thursday. High
temperatures will be in the upper 90s and 100s with heat indices
potentially exceeding 110 to 115 degrees, while morning lows well
into the 70s and nearing 80 will not provide much relief. This is
likely to set scattered daily records for maximum temperatures and
perhaps more widespread records for minimum temperatures. Farther
north, the Ohio Valley into the Mid-Atlantic and Northeast can
expect hotter than normal temperatures into the 90s with Major
HeatRisk into Tuesday, but these areas are likely to cool by
Wednesday or Thursday behind a cold front. This cold front
eventually making its way southward should finally lead to heat
relief in much of the Southeast later in the week, though Florida
could still be hot.

Rain and thunderstorms are forecast to focus on the periphery of
the ridge. Some upper jet and shortwave forcing combined with
sufficient moisture and high to extreme instability just ahead of a
front or two should lead to convection across the northern Rockies
into the north-central Plains and Mississippi Valley on Tuesday
and Wednesday. These ingredients will likely lead to heavy rain
rates, but model spread remains high with the axis of storms and
placement of heaviest rain. Another complicating factor for
potential flash flooding is the possibility of the maximum rain
amounts falling over the Nebraska Sandhills which is not a
sensitive area for heavy rain. For those reasons, held off on any
Slight Risk areas in the Day 4/Tuesday and Day 5/Wednesday EROs at
this point, but broad Marginal Risks cover these areas and
eventually Slight Risks may need to be added. Did expand the
Wednesday (D5) Marginal Risk to the East Coast to account for
potentially heavier rain in a moisture-laden pre-frontal
environment coincident with areas that have seen well above normal
rainfall the past several weeks.

Meanwhile to the west of the ridge, monsoonal moisture (with
precipitable water values generally in the 75th-90th percentile)
will be present over the Southwest with some instability. Marginal
Risks are in place in the Days 4 and 5 EROs for the Southwest and
reaching into the central Rockies/High Plains as the monsoonal
moisture meets the frontal system to the north. The central Rockies
and Plains look to be areas of focus for heavy rain into Thursday
and Friday as well.

Elsewhere, moisture and instability could lead to scattered
thunderstorms in parts of the eastern half of the U.S. from day to
day. There may be some focus for storms over northern
Florida/southern Georgia Tuesday and near the central Gulf Coast
Wednesday as a surface/low level trough/weak low retrogrades.
Marginal Risks of flash flooding are in place for those areas due
to high rain rates that may overcome the high Flash Flood Guidance
and/or fall atop urban areas. Farther north, moisture pooling along
the front pushing southward could enhance rainfall from the Mid-
Atlantic southward into the Carolinas Thursday into Friday.


Fracasso/Tate


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 (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
250 PM EDT Sun Jul 27 2025

...Dangerous heat wave persists in the Southeast through midweek
with gradual relief later in the week...

...Heavy rain and flash flooding potential in the central Plains
for multiple days...


...Overview...

By the start of the medium range period midweek, the sprawling
upper high atop much of the U.S. early this week will be weakening
somewhat and be pressed south by a northern stream upper trough.
Dangerous heat is possible across the Lower Ohio/Tennessee Valleys
and Mid-Atlantic Wednesday before a cold front (tied to the upper
trough) moves through. The Southeast is forecast to see the heat
continue into late week but gradually shrink in scope. Complexes of
showers and storms are likely near and ahead of the frontal system
stretching from the High Plains eastward across the central
Plains/Mid-Mississippi Valley into the Northeast Wednesday. The
front is likely to stall near the central Plains and lead to
multiple days of storms with heavy rain that could cause flash
flooding. Farther east the cold front should be more progressive,
making its way southward across the Mid-Atlantic and Southeast but
creating an environment for possibly heavy rain each day as it
moves. Meanwhile, southerly flow will bring monsoonal moisture into
parts of the Southwest states for possibly heavy rain.


...Guidance/Predictability Assessment...

Model agreement is excellent for the overall pattern through late
this week. Models have been persistent in showing the expansive
upper high shrinking in scope by Wednesday and becoming centered
over the southern Plains late week, with perhaps another
subtropical high moving across Florida. Meanwhile the ridge axis
will stretch northward across the northern Rockies into western
Canada starting Tuesday, coincident with the upper trough edging
into the north-central to northeastern U.S. anchored by a large
Hudson Bay to eastern Canada upper low. Since model differences
were mostly negligible through late week, used a deterministic
blend of the latest 00Z/06Z guidance for the first half of the
forecast period. Regardless of the large scale agreement,
shortwaves riding around the ridge will cause more differences in
sensible weather like frontal placement, and convection will have
further uncertainties due to small boundaries like outflows
interacting. These tend not to become clearer until the short range
or near term, so the details of QPF remain uncertain, but at least
the overall pattern seems set.

By next weekend, model differences start to increase as the
pattern becomes more quasi-zonal and uncertain shortwaves become
more dominant. One larger scale model difference was the pattern in
the Northwest especially by next Sunday. This will be influenced
by a large Northeast Pacific upper low with somewhat uncertain
placement. The models have wavered on how much and how quickly to
lower heights into the Northwest/Rockies with no clear consensus.
The AI/ML models indicated a bit more troughing east of 120W than
the dynamical ensembles, but that is still likely within the
noise/spread. Balance the day 6-7 forecast with a blend of some
ensemble mean weighting along with continuity. This resulted in few
changes overall from the previous forecast.


...Weather/Hazards Highlights...

Another hot day is forecast from the south-central U.S. into the
Southeast, Tennessee and Ohio Valleys, and much of the Eastern
Seaboard on Wednesday underneath the (albeit shrinking) upper high.
HeatRisk is mainly in the Major (level 3/4) category with some
embedded Extreme (level 4/4) areas with highs generally in the 90s
to near/exceeding 100 with higher heat indices (nearing 110F),
while morning lows well into the 70s and nearing 80 will not
provide much relief. A few more daily records for temperatures
could be set into Wednesday. On Thursday, the cold front will pass
through the Ohio Valley to Mid-Atlantic and bring near to below
normal temperatures, with the heat wave becoming more limited to
the Southeast/Carolinas. The gradual movement of the front
southward should finally lead to heat relief in the Southeast
Friday-Saturday, though Florida could still be hot. Cooler than
average temperatures (especially highs) are likely in the
northern/central Plains on the cool side of the front and with the
clouds and rain chances -- some locations may even challenge record
cool maxes for the day (low 70s).

Rain and thunderstorms are forecast to focus on the periphery of
the ridge, enhanced by a frontal boundary across the northern
Rockies into the north-central Plains and Mississippi Valley. Some
shortwave forcing and above normal moisture and instability should
lead to multiple rounds of convection with high rain rates, and
some areas could see repeating rounds of storms with the front
stalling. Thus, the Day 4/Wednesday and Day 5/Thursday EROs show
Slight Risks over the central Plains for the possibility of flash
flooding. On Day 4/Wednesday, also have the Slight Risk looping
east into the Middle Mississippi Valley where models show MCS
potential and antecedent conditions are generally wet. Marginal
Risks stretch northward into the northern Rockies/High Plains near
the back end of the front as much higher than average instability
(per the Extreme Forecast Index) is in place. Meanwhile the front
extends farther east across the Ohio Valley and Northeast on
Wednesday, promoting potentially heavier rain in a moisture-laden
pre-frontal environment coincident with areas that have seen well
above normal rainfall the past several weeks, allowing for a
Marginal Risk in the Day 4/Wed ERO. By Thursday, the front will
gradually move south and lead to pooling moisture and instability
in the Mid-Atlantic along with increasing dynamical support in the
form of the right entrance region of the upper jet. A Slight Risk
is noted in the Day 5/Thu ERO for this activity. Enhanced rain is
possible in the Carolinas by Friday and Saturday near this front.

To the west of the ridge, monsoonal moisture (with precipitable
water values generally in the 75th-90th percentile) will be present
over the Southwest with some instability. Marginal Risks are in
place in the Days 4 and 5 EROs for parts of the Southwest and
reaching into the central Rockies/High Plains as the monsoonal
moisture meets the frontal system to the north.

Elsewhere, moisture and instability could lead to scattered
thunderstorms in the southeastern U.S. from day to day. There may
be some focus for storms near the central Gulf Coast in particular
with weak low level troughs/lows in the vicinity. Marginal Risks of
flash flooding are in place for the central Gulf Coast and parts
of the Southeast due to high rain rates that may overcome the high
Flash Flood Guidance and/or fall atop urban areas.


Fracasso/Tate


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 (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
215 PM EDT Mon Jul 28 2025

Valid 12Z Thu Jul 31 2025 - 12Z Mon Aug 04 2025

...Heavy rain and flash flooding potential along the East Coast
later this week...

...Overview...

A reasonably strong cold front for late July-early August is
forecast to push southward across the East at the leading edge of
an upper trough later this week into the weekend. Moisture and
instability along and ahead of the front will promote heavy to
excessive rainfall in thunderstorms that could cause localized
flash flooding. The front and upper trough should also displace
upper ridging causing a heat wave in the short term, limiting the
heat to the Southeast Thursday and gradually lessening in scope and
magnitude by the weekend. The front will stretch westward into the
south-central U.S. and bend northward across much of the Plains.
Complexes of showers and storms are likely in the interior
Northwest to the central U.S. for multiple days with shortwaves
moving through the flattening upper flow. Monsoonal moisture could
continue to cause showers and storms in parts of the Southwest
through late week with lessening rain chances by the weekend.


...Guidance/Predictability Assessment...

Model guidance remains in good agreement for the early medium
range period late week. Upper highs embedded within a southern U.S.
ridge will be in place, generally retrograding from the southern
Plains to Southwest and from the western Atlantic across Florida
into the Gulf. The ridge axis extends into the High Plains while an
upper trough extends from eastern Canada into the eastern U.S. on
Thursday-Friday. The WPC forecast used a blend of the latest
00Z/06Z guidance to start, though the 00Z Canadian was first to
become most dissimilar in the West by the weekend. Smaller scale
features could still cause differences in frontal placement and QPF
though.

By the weekend, model differences start to increase as the pattern
becomes more quasi-zonal and uncertainty in shortwave
track/timing/amplitude increases. The largest guidance difference
was the pattern in the Northwest by Sun-Mon. This will be
influenced by a large Northeast Pacific upper low with somewhat
uncertain placement. Models have become less clustered and the
AI/ML models/ensembles have trended toward increased Western
troughing (even downstream into the Rockies). This was in contrast
to some dynamical models showing increased ridging over the Four
Corners a the same time. Thus, used a majority ensemble mean
weighting by the end of the period mostly with the ECMWF ensemble
mean.


...Weather/Hazards Highlights...

The cold front pushing through the East will provide a focus for
ample moisture and instability to pool while there should be
increasing dynamical support in the form of the right entrance
region of the upper jet. High rain rates in widespread
thunderstorms should lead to a flash flooding risk -- a Slight Risk
remains in place in the Day 4/Thursday ERO for the Mid- Atlantic,
parts of which are starting with wetter than average antecedent
conditions that could augment the flooding risk. The Slight
includes Southern New England/NYC due to uncertainty in how quickly
the front may progress southward. By Friday the front is forecast
to push into the Carolinas, and a Slight Risk is noted for the Day
5/Friday ERO into the southern Appalachians and eastern Georgia
with similar environmental factors as Thursday farther north. The
Carolinas may see additional convection into the weekend. The front
stretching west across the Gulf Coast states in a moist and
unstable environment could promote scattered diurnal thunderstorms
there through late week into the weekend, and Marginal Risks are in
place in the Day 4/5 EROs due to high rain rates that may overcome
the high Flash Flood Guidance and/or fall atop urban areas.

Farther west as the front bends back into the Plains, rounds of
rain and thunderstorms are likely with possibly multiple MCSs. Some
shortwave forcing and above normal moisture and instability should
lead to high rain rates, and some areas could see repeating rounds
of storms with the front stalling. Models have trended toward an
earlier focus for heavier rainfall over CO into D3 rather than D4,
and the Slight Risk was moved into the D3 period. Broad Marginal
Risks cover much of the High Plains on both Days 4 and 5 and back
into the northern Rockies/High Plains near the back end of the
front as much higher than average instability (per the Extreme
Forecast Index) is in place. Farther south, monsoonal moisture
(with precipitable water values generally in the 75th-90th
percentile) will be present over parts of the Southwest along with
some instability, but overall the Monsoon season remains drier than
normal especially for UT/AZ. Marginal Risks are in place in the
Days 4 and 5 EROs for parts of the Southwest, reaching into the
central Rockies/High Plains as as the monsoonal moisture meets the
frontal system to the north. Moisture looks to lessen in the
Southwest by the weekend.

Another hot day is forecast for the Carolinas into Georgia and
Florida Thursday ahead of the cold front and under what remains of
the short range upper ridge. HeatRisk is mainly in the Major (level
3/4) category with some embedded Extreme (level 4/4) areas as
temperatures reach well into the 90s with higher heat indices
(nearing 110F), while morning lows well into the 70s and nearing 80
will not provide much relief. The cold front gradually passing
through the Southeast will bring moderating temperatures, and
Florida will be the last to see relief from the heat this weekend.
Cooler than average temperatures (especially highs) are likely in
the northern/central Plains on the cool side of the front and with
the clouds and rain chances -- a few locations may even challenge
record cool maxes for the day (low 70s). Meanwhile the Southwest
can expect seasonable heat (near to slightly above average), with
the lower desert areas seeing temperatures 105-110 degrees.


Fracasso/Tate


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 (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
154 PM EDT Tue Jul 29 2025

Valid 12Z Fri Aug 01 2025 - 12Z Tue Aug 05 2025

...Heavy rain and flash flooding potential in the
Carolinas/Southeast late week...

...Overview...

A reasonably strong cold front for late July-early August is
forecast to push into the Southeast at the leading edge of an upper
trough late week into the weekend. Moisture and instability along
and ahead of the front will promote heavy to excessive rainfall in
thunderstorms that could cause localized flash flooding. The front
and upper trough should also displace the upper ridging which is
responsible for the heat wave in the short term, limiting the heat
to Florida/southern Georgia Friday and gradually lessening in scope
and magnitude by the weekend. The front will stretch westward into
the south-central U.S. and bend northward across much of the
Plains. Complexes of showers and storms are likely in the central
U.S. back into the northern Rockies for multiple days due to the
front as well as shortwaves moving through the flattening upper
flow. Monsoonal moisture could continue to cause showers and storms
in parts of the Southwest through late week with lessening rain
chances by the weekend.


...Guidance/Predictability Assessment...

Model guidance starts the medium range period in reasonably good
agreement on the larger scale. A general southern U.S. upper ridge
may be split by lower heights in the south-central U.S. at times,
and into early next week the eastern side of the 594+ ridge over
Florida and the Gulf should ease and leave the ridge more limited
to the Southwest. There is some uncertainty with how much heights
will lower in the Southeast by early next week though as some
models deepen the trough more than others. Meanwhile ridging will
pass across the north-central U.S. late week, with mean troughing
in the Northwest. There is a general signal for the central U.S.
ridge to become suppressed by shortwaves by early next week, but
ample uncertainty in the details. Additionally, there remain model
differences with timing and amplitude of troughing reaching the
western U.S., as an upper low moves from the northeast Pacific
eastward across Southeast Alaska and into western Canada with
varied model solutions. Most of the 00Z/06Z guidance trended toward
broader troughing to the western High Plains with the exception
being the 00Z Canadian which showed a much stronger upper high over
the Southern Plains. Preferred sticking with the larger/broader
consensus through the period with an increased in ensemble mean
weighting by day 6-7.


...Weather/Hazards Highlights...

The cold front pushing through the Mid-Atlantic to Southeast will
provide a focus for ample moisture and instability to pool while
there should be increasing dynamical support in the form of the
right entrance region of the upper jet. High rain rates in
widespread thunderstorms should lead to a flash flooding risk -- a
Slight Risk remains in place in the Day 4/Friday ERO for the
Carolinas to southern Appalachians. By Friday the front is forecast
to push a bit south, with the best focus for heavy rain and flash
flooding generally in South Carolina and Georgia, where a Slight
Risk is delineated for Day 5/Saturday. The front stalling there
into early next week could lead to additional convection. The front
stretching west across the Gulf Coast states in a moist and
unstable environment could promote scattered diurnal thunderstorms
there through late week into the weekend, and Marginal Risks are in
place in the Day 4/5 EROs due to high rain rates that may overcome
the high Flash Flood Guidance and/or fall atop urban areas.

Farther west as the front bends back into the Plains, rounds of
rain and thunderstorms are likely with possibly multiple MCSs. Some
shortwave forcing and above normal moisture and instability should
lead to high rain rates, and some areas could see repeating rounds
of storms with the front stalling. Broad Marginal Risks cover much
of the Plains on Days 4 and 5 and back into the northern
Rockies/High Plains near the back end of the front as much higher
than average instability (per the Extreme Forecast Index) lingers
before lessening early next week. No Slight Risk areas are noted at
this time due to uncertainties in rainfall placement and the
localized/isolated nature of the thunderstorm complexes. Meanwhile
some monsoonal moisture is forecast to linger especially in New
Mexico on Friday, prompting a continued Marginal Risk there and
stretching into Colorado as the moisture meets the frontal system.
Moisture looks to become more limited to eastern New Mexico
Saturday and lessen even more early next week, furthering the
relatively dry monsoon season especially across Utah/Arizona.

The cold front pushing through the Southeast will continue to
lessen the scope of dangerous heat late week. On Friday, heat will
be located across southern Georgia into Florida, where HeatRisk
remains in the Major (level 3/4) and Extreme (level 4/4)
categories, as temperatures reach well into the 90s with higher
heat indices (nearing 110F), while morning lows well into the 70s
and nearing 80 will not provide much relief. Florida may see hot
conditions continuing into Saturday as the front stalls north of
the state, but thunderstorm chances increase there over the weekend
and early next week, which should limit extreme heat. Behind the
front, cooler than average temperatures (especially highs) are
likely. Into the weekend, highs of 5-10 degrees below normal are
forecast in the East, while much of the Plains can expect highs of
10-15 degrees below average, with highs in the 70s as far south as
Kansas and the Oklahoma Panhandle. Temperatures should gradually
warm across those areas into early next week. Meanwhile the
Northwest can expect below normal temperatures as rounds of
troughing move through. But farther south, the Southwest can expect
seasonable heat (near to slightly above average), with the lower
desert areas seeing temperatures 105-110+ degrees.


Fracasso/Tate


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 (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
300 PM EDT Wed Jul 30 2025

Valid 12Z Sat Aug 02 2025 - 12Z Wed Aug 06 2025

...Heavy rain and flash flooding potential for the Southeast into
the weekend especially for areas closer to the coast...

...Overview...

A rather broad and deep upper trough is forecast to settle into the
eastern U.S. by this weekend as the western U.S. upper ridge
attempts to edge east toward the High Plains by the middle of next
week. Disturbances rounding the eastern edge of the ridge should
trigger rounds of thunderstorms and possibly heavy rain across
portions of the central/southern Plains this weekend and across the
northern Plains this weekend and toward the middle of next week.
Meanwhile, heavy rain threat across portions of the Southeast this
weekend should gradually spread northward up the eastern U.S.
toward the middle of next week with a more localized heavy rain
threat.


...Guidance/Predictability Assessment...

Model guidance remains in relatively good agreement through the
medium-range period. The WPC medium-range forecasts lean toward the
ECMWF cluster, with QPF farther south into the southern Plains for
this weekend.


...Weather/Hazards Highlights...

A rather strong cold front for early August is forecast to push
into the Southeast with the arrival of a positively-tilted upper
trough into the East Coast this weekend. High moisture content and
instability along and ahead of the front interacting with the right
entrance region of the upper jet will promote heavy to excessive
rainfall in thunderstorms that could cause localized flash
flooding. High rain rates in widespread thunderstorms should lead
to a flash flooding risk -- a Slight Risk remains in place in the
Day 4/Saturday ERO for southern Georgia into southern South
Carolina. The front stretching west across the Gulf Coast states in
a moist and unstable environment could promote scattered diurnal
thunderstorms into Saturday, and a Marginal Risk is in place in the
Day 4 ERO due to high rain rates that may overcome the high Flash
Flood Guidance and/or fall atop urban areas. By Sunday, the front
will push south a bit more and clear the central Gulf Coast from
seeing much rain, but thunderstorm chances linger from the Florida
Panhandle northward across parts of the Southeast. A Marginal Risk
is delineated for the Day 5/Sunday ERO for this activity. The front
is forecast to become nearly stationary from along the Gulf Coast
to just off the Southeast U.S. by early next week, which should
maintain scattered convection across the Southeast.

Farther west, shortwaves rounding the eastern edge of the upper
ridge in the western U.S. is forecast to interact with the same
front that bends back across the Great Plains, where rounds of
rain and thunderstorms are likely with possibly multiple MCSs.
Above normal moisture and instability should support high rain rates
at times, with some areas possibly seeing repeated rounds of storms
as the front begins to lift as a warm front. Broad Marginal Risks
cover much of the Plains on Day 4/Saturday, as well as back into
the northern Rockies/High Plains near the back end of the front as
much higher than average instability (per the Extreme Forecast
Index) lingers before lessening early next week. No Slight Risk
areas are noted at this time due to uncertainties in rainfall
placement and the localized/isolated nature of the thunderstorm
complexes. Also looped the Marginal Risk around southeastern New
Mexico where some monsoonal moisture could linger Saturday and
create isolated flooding issues over sensitive burn scars. By
Sunday the elongated front is forecast to move a bit east, with the
thunderstorm chances moving with it. A Marginal Risk encompasses
the Plains into parts of the Mississippi Valley for the Day
5/Sunday ERO for likely additional rounds of MCSs. The details are
uncertain at this point, but there is a general trend for the
Ohio/Tennessee Valley into the East to see increasing rain and
thunderstorms by Monday-Tuesday as the front continues moving east.
Meanwhile the Southwest should dry out around Sunday, but there
may be a bit of a monsoonal moisture return by Monday-Tuesday over
Arizona/New Mexico amid the relatively dry monsoon season
especially across Utah/Arizona.

The cold front pushing through the Southeast will continue to
lessen the scope of dangerous heat into Saturday. Florida can
expect some heat to linger though, where HeatRisk remains in the
Major (level 3/4) and Extreme (level 4/4) categories, as
temperatures reach well into the 90s with higher heat indices
(nearing 110F), while morning lows well into the 70s and nearing 80
will not provide much relief. But thunderstorms are forecast to
increase in Florida early next week and limit extreme heat. Behind
the front, cooler than average temperatures (especially highs) are
likely. Into the weekend, highs of 5-10 degrees below normal are
forecast in the East, while much of the Plains can expect highs of
10-15 degrees below average, with highs in the 70s as far south as
parts of Kansas and Missouri. Temperatures should gradually warm
across those areas into early next week. Meanwhile the Northwest
can expect below normal temperatures as rounds of troughing move
through. But farther south, the Southwest can expect seasonable
heat (near to slightly above average), with the lower desert areas
seeing temperatures 105-110+ degrees.


Kong/Tate


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 (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

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