Weather Prediction Center

National Oceanic and Atmospheric Administration

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
346 PM EDT Tue May 20 2025

Valid 00Z Wed May 21 2025 - 00Z Fri May 23 2025

...Severe Weather and Flash Flooding expected over the
Ohio/Tennessee/Mississippi Valleys today; Mid-Atlantic/Northeast
tomorrow...

...Above average temperatures across southern tier states; below average
temperatures across the northern tier...

After an active 48 hours of severe weather and heavy rainfall over the
nation's midsection, well defined low pressure is forecast to shift
unsettled weather eastward into the Ohio/Tennessee/Lower Mississippi
Valleys today, and Mid-Atlantic/Northeast tomorrow. Per the Storm
Prediction Center, the forecast remains on track for an Enhanced Risk
(level 3/5) of severe thunderstorms, where tornadoes (some strong),
scattered to widespread damaging winds, and isolated significant severe
hail are all on the table through tonight as storms form ahead of a
sweeping cold front. Excessive rainfall rates and periodic cell training
within the same storms should also support isolated to scattered instances
of flash flooding across much of the same area today, where a Slight Risk
(level 2/4) of Excessive Rainfall is in effect. By tomorrow, moist soils
in the Mid-Altantic/Northeast will support a Slight Risk (at least 15%) of
Excessive Rainfall as several rounds of storms are expected. A more
unstable environment to the south will allow for increased thunderstorm
activity and the potential for isolated severe storms along the
Southeast/Mid-Atlantic Coast.

Upper troughing over southern Canada and the northern tier of the U.S.
will allow for a cooler airmass to park over the region through late this
week. High temperatures in the 40s and 50s will be 20-35 degrees below
average for parts of the Northern Plains and Upper Midwest today and
tomorrow. Meanwhile, a quasi-zonal, ridge-like pattern over the southern
tier will supply ample warm air into the region over the next few days.
Widespread high minimum temperature records may be tied or broken across
the Southeast and Southern California over the next couple of nights.

Asherman/Kebede


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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue May 20 2025

Valid 12Z Fri May 23 2025 - 12Z Tue May 27 2025


...Multi-day heavy rain threat in the Ozarks peaking this
weekend...


...Overview...

An omega-type pattern is forecast atop North America as the medium
range period begins Friday, as ridging amplifies in the central
U.S. while rounds of troughing move through the Northwest and an
upper low spins over the Great Lakes/Northeast. Cooler than average
temperatures should prevail under the eastern trough along with
some showers in the Northeast continuing Friday, while warmer than
average temperatures are likely underneath the ridge in the Four
Corners states to southern Plains and then over the Great Basin
early next week as the ridge rebuilds farther west. Frontal systems
emerging from the West toward the Plains and moist inflow ahead of
them will allow for increasing rain and thunderstorm chances in
the central U.S. from late week into the weekend. Multiple days of
heavy rain may occur focused in the Ozarks and vicinity and cause
flash flooding concerns.


...Guidance/Predictability Assessment...

Model guidance remains in fairly good agreement with the depiction
of the large scale pattern through the medium range period,
particularly early on. The primary sources of uncertainty continue
to stem from the interaction of several shortwaves downstream of a
developing western ridge and upstream of a slow-to-breakdown,
pinwheeling upper low over the northeastern U.S this weekend into
next week. Fortunately, there has been some recent improvement
within the latest pieces of guidance, aside from the typical
uncertainties of smaller scale disturbances with shorter
wavelengths. The 00Z (and 12Z) UKMET was much more in line with
consensus with the evolution of the eastern trough this weekend and
therefore was able to be incorporated into the forecast blend
noted below. The CMC, which was not usable at 00Z, was much
improved at 12Z, no longer showing the large closed upper low
digging across the Pacific Northwest and the Upper Midwest this
weekend into early next week. Otherwise, the big picture being
advertised by the models remains the same, showing a large omega
block across North America breaking down through the weekend before
reloading and becoming re-established by the middle of next week.

The WPC forecast was based on a blend of the 06Z GFS, the 00Z
ECMWF and the 00Z UKMET, with the heaviest weighting placed on the
GFS/ECMWF solutions. Like the 12Z run, the 00Z CMC was also not
considered with this package given large differences from the
multi-model consensus. As the period progressed, included and
increased the proportion of the GEFS and EC ensemble means, with
the means making up half of the total blend by Day 7.


...Weather/Hazards Highlights...

A prolonged heavy rainfall pattern over the central U.S. will set
up ahead of frontal systems on Friday with ample Gulf moisture
streaming north from return flow from high pressure over the
Southeast. This convection in the mean northwest flow should be
organized at times starting Friday afternoon over the south-central
Plains to the Ozarks. A Marginal Risk remains in place for Day
4/Friday in these areas. Then by Saturday, moisture and instability
are likely to further increase in these areas in response to a
shortwave coming into the north-central Rockies and High Plains.
Rain and storms are likely to overlap with Friday's convection
where there will be wetter antecedent conditions. A Slight Risk
remains centered over the Ozarks (which can be sensitive to flash
flooding anyway) for the Day 5/Saturday ERO. Yet another round of
rain is expected Sunday in similar areas, before finally pressing
south Monday, though there is still uncertainty in positioning of
heavy rain by then.

Precipitation, in the form of rain except for snow in the highest
peaks, is possible across the northwestern to north-central U.S.
Friday night/Saturday underneath upper troughing and as frontal
systems move through. The details are uncertain based on the model
spread with the supporting energies. But the shortwave providing
dynamical support, above normal PWs, and the cusp of the
instability gradient could provide some heavy rain and a low end
flash flood risk in the north-central High Plains. A Marginal Risk
is in place there for the Day 5/Saturday ERO.

Elsewhere, showers with modest QPF could continue across the
Northeast Friday and gradually lessen in magnitude through the
weekend as the upper and surface lows are slow to pull away there.
Summertime scattered storms are likely across the Florida Peninsula
through the period. The Northwest may see renewed precipitation
chances early next week.

Warmer than normal temperatures will be in place from the
Southwest and Four Corners states into the southern Plains on
Friday underneath the upper ridge. Temperatures are forecast to
gradually moderate closer to normal into the weekend, aside from
Texas staying warm. Then as the mean upper ridge rebuilds farther
west, the Great Basin and northern/central Rockies can expect
temperatures generally around 10-15 degrees above average.
Meanwhile, cooler than normal temperatures will take hold over the
north-central to eastern U.S. late this week and into the weekend
underneath upper troughing. Highs of 10-20 degrees below average
will be common in the Appalachians to Northeast on Friday in
particular before slowly moderating as the upper low drifts
northeast.


Miller/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

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
358 AM EDT Tue May 20 2025

Valid 00Z Wed 21 May 2025 - 00Z Wed 28 May 2025


Moderate to breezy easterly trades are likely through the rest of
this week as midlatitude surface high pressure systems track well
north of Hawaii. A weak midlevel low centered just east of the
state will give way to a broader trough aloft for the latter part
of the week, allowing for a raised inversion, while normal to
above normal moisture levels are in place. This will add up to a
wet trade wind pattern with showers favoring windward and mauka
areas, as well as leeward areas of the Big Island, with the
heaviest showers most likely Thursday-Friday. Model guidance
continues to show moisture levels decreasing by early next week
especially for the western islands, while easterly trades persist.


Tate

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
828 PM EDT Tue May 20 2025
Day 1
Valid 01Z Wed May 21 2025 - 12Z Wed May 21 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
OHIO AND TENNESSEE VALLEYS...

...01Z Update...
Few changes to the forecast reasoning expressed in earlier
Excessive Rainfall Discussions. The western portion of the Marginal
and the Slight risk areas were trimmed out behind a cold front that
was ushering drier and more stable air into the region. Ahead of
the front...the airmass remained conducive for convection with
downpours and heavy rainfall amounts falling on increasingly
saturated soils.

Bann

...16Z Update...

There were some subtle adjustments to the Marginal Risk in the
Mid-Atlantic and Upper Midwest based on 12Z guidance trends, but
the most concerning area for flash flooding remains in the Ohio and
Tennessee Valleys. The setup features an ideal setup for both
synoptic and mesoscale forcing to go along with anomalous PWs
(above the 90th climatological percentile per NAEFS) and a strong
IVT for mid-late May (500-750 kg/m/s). Latest RAP guidance shows
the first round of storms continuing to progress east this
afternoon, while the next line of storms forms along and east of
the cold front tracking across the Middle Mississippi Valley where
surface-based heating is on going. As the atmosphere destabilizes,
additional storms will form and add to the repeated rounds of
storms throughout the Mid-South through this evening. RAP soundings
in portions of eastern KY show sfc-500mb RH values >90%, MLCAPE
>1,000 J/kg, and warm cloud layer depths of at least 10,000ft. The
potential for training storms, particularly from as far south as
northern MS/AL and and far north and east as western WV, also
aligns in areas where 10-40cm soil moisture is >70% in some cases.
These storms should be progressive movers, but given the potential
for some localized training and increasingly sensitive soils, the
Slight Risk still remains on track for parts of the Mid-South
through tonight.

Mullinax

---Previous Discussion---

A deeply negatively tilted longwave trough stretching from Montana
to the mid-Mississippi Valley will continue flattening by becoming
even more negatively tilted through the period as the trough itself
lifts back into the broader more zonal jet stream. While this
trough will continue to support a surface low as it moves east from
Iowa to roughly the IN/OH/MI tripoint by 12Z Wed, the low will be
weakening with time. The low will be filling in part because the
zonal pattern will gradually decouple the low from the plume of
Gulf moisture as the LLJ that has been supporting the storms over
the middle of the country the past couple days gets shunted south
back towards the Gulf Coast. The result of this will be decreasing
amounts of atmospheric moisture available for the storms with time,
resulting in a subsequently decreasing flash flooding threat.
However, for this period, the southwesterly influx of Gulf moisture
will feed training storms across the Ohio and Tennessee Valleys,
including portions of eastern Kentucky and southern West Virginia
which were hard hit with heavy rain and severe storms over the past
week or so.

The inherited Slight Risk area was trimmed on the northwest side
due to a lack of instability over much of Illinois, but expanded a
few rows of counties across Tennessee towards the south and west.
No significant changes were made to the surrounding Marginal Risk.

Wegman

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

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
828 PM EDT Tue May 20 2025
Day 2
Valid 12Z Wed May 21 2025 - 12Z Thu May 22 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR A PORTION OF
THE CENTRAL APPALACHIANS...

The Slight Risk remains largely unchanged with only minor
adjustments based on the most recent guidance. Most of the 12Z
guidance (aside from the RRFS) has sped up timing of precipitation
and also shifted to the north/northeast. This would lower the
probability of flash flooding across portions of northern West
Virginia while increasing it somewhat over western/central PA so
the Slight was adjusted accordingly.

---previous discussion---

A Slight Risk upgrade was introduced with this update for a
portion of southwestern Pennsylvania, northern West Virginia,
eastern Ohio, and far western Maryland. New shortwave energy will
begin to tug an upper level low north of Lake Superior southward
into the Midwest on Wednesday. Meanwhile, an active subtropical jet
and associated 110 kt jet streak will also round the base of that
upper level low. The cold air aloft associated with the upper low
is expected to locally increase instability across the Slight Risk
area Wednesday afternoon, while the multiple shortwaves moving
through result in a rather compact area with multiple rounds of
showers and thunderstorms moving through in rapid succession. This
portion of the central Appalachians is particularly sensitive to
flash flooding, as well as the urban concerns in and around the
Pittsburgh metro. While there is still limited guidance on the
nature of the storms, the RRFS solution suggests the above
convective evolution Wednesday and into Wednesday night.

Two big questions still remain...how far north will significant
instability get and how will this instability align with the
greatest forcing, likely to set up in and just north of the Slight
Risk area. A total elimination of instability shouldn't prevent
training convection, but it's likely to be mostly showers and
unlikely to result in more than isolated flash flooding. Further,
any northward shift in the track of the repeating shortwave
impulses could also reduce the flash flooding threat. Meanwhile a
more northward expansion of the instability or a slightly further
south track to the upper level energy could both enhance the flash
flooding threat. Thus, the consensus was a low end Slight with a
southward bias towards the greater instability.

Elsewhere, the Marginal Risk across the Northeast was trimmed
largely due to a certain lack of instability. While areas such as
NYC are likely to see periods of light rain for much of the period,
the stratiform nature should limit rainfall rates to a half inch
per hour at most, precluding any more than some ponding on roads.

The Marginal Risk in deep south Texas was trimmed on its eastern
side but expanded north. Convection is expected to develop along
the mountains of Mexico, but is unlikely to drift too far east off
those mountains, narrowing the flash flooding threat to the
immediate Rio Grande Valley.

Wegman

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

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
828 PM EDT Tue May 20 2025
Day 3
Valid 12Z Thu May 22 2025 - 12Z Fri May 23 2025

No change in thinking for Day 3, with the potential for localized
heavy rain across southern New England. Guidance still shows the
potential for 1-2" with localized amounts up to 3", but with the
lack of sufficient instability, rain rates should be lower and make
for a widespread, stratiform rain. Urban ponding issues may develop
but probability for flash flooding is less than 5 percent.

Taylor

---previous discussion---

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

The inherited Marginal across eastern New England was downgraded
with this update in coordination with BOX/Taunton, MA and
OKX/Upton, NY forecast offices. The broad 1-2 inches of rainfall
expected through the period will be from a wound up low that will
develop off the coast. The low should shove any instability to its
east out to sea, resulting in only stratiform rain across New
England. While there may be a few urban concerns in Boston and
Providence, the low rainfall rates should favor more ponding and
very little, if any, flash flooding.

Wegman

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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue May 20 2025


A prolonged heavy rainfall pattern over the central U.S. will set
up ahead of frontal systems on Friday with ample Gulf moisture
streaming north from return flow from high pressure over the
Southeast. This convection in the mean northwest flow should be
organized at times starting Friday afternoon over the south-central
Plains to the Ozarks. A Marginal Risk remains in place for Day
4/Friday in these areas. Then by Saturday, moisture and instability
are likely to further increase in these areas in response to a
shortwave coming into the north-central Rockies and High Plains.
Rain and storms are likely to overlap with Friday's convection
where there will be wetter antecedent conditions. A Slight Risk
remains centered over the Ozarks (which can be sensitive to flash
flooding anyway) for the Day 5/Saturday ERO. Yet another round of
rain is expected Sunday in similar areas, before finally pressing
south Monday, though there is still uncertainty in positioning of
heavy rain by then.

Precipitation, in the form of rain except for snow in the highest
peaks, is possible across the northwestern to north-central U.S.
Friday night/Saturday underneath upper troughing and as frontal
systems move through. The details are uncertain based on the model
spread with the supporting energies. But the shortwave providing
dynamical support, above normal PWs, and the cusp of the
instability gradient could provide some heavy rain and a low end
flash flood risk in the north-central High Plains. A Marginal Risk
is in place there for the Day 5/Saturday ERO.

Elsewhere, showers with modest QPF could continue across the
Northeast Friday and gradually lessen in magnitude through the
weekend as the upper and surface lows are slow to pull away there.
Summertime scattered storms are likely across the Florida Peninsula
through the period. The Northwest may see renewed precipitation
chances early next week.

Warmer than normal temperatures will be in place from the
Southwest and Four Corners states into the southern Plains on
Friday underneath the upper ridge. Temperatures are forecast to
gradually moderate closer to normal into the weekend, aside from
Texas staying warm. Then as the mean upper ridge rebuilds farther
west, the Great Basin and northern/central Rockies can expect
temperatures generally around 10-15 degrees above average.
Meanwhile, cooler than normal temperatures will take hold over the
north-central to eastern U.S. late this week and into the weekend
underneath upper troughing. Highs of 10-20 degrees below average
will be common in the Appalachians to Northeast on Friday in
particular before slowly moderating as the upper low drifts
northeast.


Miller/Tate

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue May 20 2025


A prolonged heavy rainfall pattern over the central U.S. will set
up ahead of frontal systems on Friday with ample Gulf moisture
streaming north from return flow from high pressure over the
Southeast. This convection in the mean northwest flow should be
organized at times starting Friday afternoon over the south-central
Plains to the Ozarks. A Marginal Risk remains in place for Day
4/Friday in these areas. Then by Saturday, moisture and instability
are likely to further increase in these areas in response to a
shortwave coming into the north-central Rockies and High Plains.
Rain and storms are likely to overlap with Friday's convection
where there will be wetter antecedent conditions. A Slight Risk
remains centered over the Ozarks (which can be sensitive to flash
flooding anyway) for the Day 5/Saturday ERO. Yet another round of
rain is expected Sunday in similar areas, before finally pressing
south Monday, though there is still uncertainty in positioning of
heavy rain by then.

Precipitation, in the form of rain except for snow in the highest
peaks, is possible across the northwestern to north-central U.S.
Friday night/Saturday underneath upper troughing and as frontal
systems move through. The details are uncertain based on the model
spread with the supporting energies. But the shortwave providing
dynamical support, above normal PWs, and the cusp of the
instability gradient could provide some heavy rain and a low end
flash flood risk in the north-central High Plains. A Marginal Risk
is in place there for the Day 5/Saturday ERO.

Elsewhere, showers with modest QPF could continue across the
Northeast Friday and gradually lessen in magnitude through the
weekend as the upper and surface lows are slow to pull away there.
Summertime scattered storms are likely across the Florida Peninsula
through the period. The Northwest may see renewed precipitation
chances early next week.

Warmer than normal temperatures will be in place from the
Southwest and Four Corners states into the southern Plains on
Friday underneath the upper ridge. Temperatures are forecast to
gradually moderate closer to normal into the weekend, aside from
Texas staying warm. Then as the mean upper ridge rebuilds farther
west, the Great Basin and northern/central Rockies can expect
temperatures generally around 10-15 degrees above average.
Meanwhile, cooler than normal temperatures will take hold over the
north-central to eastern U.S. late this week and into the weekend
underneath upper troughing. Highs of 10-20 degrees below average
will be common in the Appalachians to Northeast on Friday in
particular before slowly moderating as the upper low drifts
northeast.


Miller/Tate

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
214 PM EDT Wed May 7 2025

Valid 00Z Thu May 08 2025 - 00Z Sun May 11 2025


...Colorado...
Day 1...

Lingering vorticity on the western side of the departing upper low
will still trigger some light snow over the San Juans this evening
before tapering off tonight/early Thursday. WPC probabilities for
at least an additional 4 inches of snow after 00Z are low (10-40%)
above 11,000ft.

For days 2-3, the probability of at least 4 inches of snow is less
than 10%.

The probability of significant freezing rain across the CONUS is
less than 10%.

Note - this is the last regularly scheduled discussion (QPFHSD)
for the 2024-2025 winter season. Unless a significant winter
weather threat emerges, this discussion will next be updated on or
about September 25, 2025.


Fracasso

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue May 20 2025

Valid 12Z Fri May 23 2025 - 12Z Tue May 27 2025


...Multi-day heavy rain threat in the Ozarks peaking this
weekend...


...Overview...

An omega-type pattern is forecast atop North America as the medium
range period begins Friday, as ridging amplifies in the central
U.S. while rounds of troughing move through the Northwest and an
upper low spins over the Great Lakes/Northeast. Cooler than average
temperatures should prevail under the eastern trough along with
some showers in the Northeast continuing Friday, while warmer than
average temperatures are likely underneath the ridge in the Four
Corners states to southern Plains and then over the Great Basin
early next week as the ridge rebuilds farther west. Frontal systems
emerging from the West toward the Plains and moist inflow ahead of
them will allow for increasing rain and thunderstorm chances in
the central U.S. from late week into the weekend. Multiple days of
heavy rain may occur focused in the Ozarks and vicinity and cause
flash flooding concerns.


...Guidance/Predictability Assessment...

Model guidance remains in fairly good agreement with the depiction
of the large scale pattern through the medium range period,
particularly early on. The primary sources of uncertainty continue
to stem from the interaction of several shortwaves downstream of a
developing western ridge and upstream of a slow-to-breakdown,
pinwheeling upper low over the northeastern U.S this weekend into
next week. Fortunately, there has been some recent improvement
within the latest pieces of guidance, aside from the typical
uncertainties of smaller scale disturbances with shorter
wavelengths. The 00Z (and 12Z) UKMET was much more in line with
consensus with the evolution of the eastern trough this weekend and
therefore was able to be incorporated into the forecast blend
noted below. The CMC, which was not usable at 00Z, was much
improved at 12Z, no longer showing the large closed upper low
digging across the Pacific Northwest and the Upper Midwest this
weekend into early next week. Otherwise, the big picture being
advertised by the models remains the same, showing a large omega
block across North America breaking down through the weekend before
reloading and becoming re-established by the middle of next week.

The WPC forecast was based on a blend of the 06Z GFS, the 00Z
ECMWF and the 00Z UKMET, with the heaviest weighting placed on the
GFS/ECMWF solutions. Like the 12Z run, the 00Z CMC was also not
considered with this package given large differences from the
multi-model consensus. As the period progressed, included and
increased the proportion of the GEFS and EC ensemble means, with
the means making up half of the total blend by Day 7.


...Weather/Hazards Highlights...

A prolonged heavy rainfall pattern over the central U.S. will set
up ahead of frontal systems on Friday with ample Gulf moisture
streaming north from return flow from high pressure over the
Southeast. This convection in the mean northwest flow should be
organized at times starting Friday afternoon over the south-central
Plains to the Ozarks. A Marginal Risk remains in place for Day
4/Friday in these areas. Then by Saturday, moisture and instability
are likely to further increase in these areas in response to a
shortwave coming into the north-central Rockies and High Plains.
Rain and storms are likely to overlap with Friday's convection
where there will be wetter antecedent conditions. A Slight Risk
remains centered over the Ozarks (which can be sensitive to flash
flooding anyway) for the Day 5/Saturday ERO. Yet another round of
rain is expected Sunday in similar areas, before finally pressing
south Monday, though there is still uncertainty in positioning of
heavy rain by then.

Precipitation, in the form of rain except for snow in the highest
peaks, is possible across the northwestern to north-central U.S.
Friday night/Saturday underneath upper troughing and as frontal
systems move through. The details are uncertain based on the model
spread with the supporting energies. But the shortwave providing
dynamical support, above normal PWs, and the cusp of the
instability gradient could provide some heavy rain and a low end
flash flood risk in the north-central High Plains. A Marginal Risk
is in place there for the Day 5/Saturday ERO.

Elsewhere, showers with modest QPF could continue across the
Northeast Friday and gradually lessen in magnitude through the
weekend as the upper and surface lows are slow to pull away there.
Summertime scattered storms are likely across the Florida Peninsula
through the period. The Northwest may see renewed precipitation
chances early next week.

Warmer than normal temperatures will be in place from the
Southwest and Four Corners states into the southern Plains on
Friday underneath the upper ridge. Temperatures are forecast to
gradually moderate closer to normal into the weekend, aside from
Texas staying warm. Then as the mean upper ridge rebuilds farther
west, the Great Basin and northern/central Rockies can expect
temperatures generally around 10-15 degrees above average.
Meanwhile, cooler than normal temperatures will take hold over the
north-central to eastern U.S. late this week and into the weekend
underneath upper troughing. Highs of 10-20 degrees below average
will be common in the Appalachians to Northeast on Friday in
particular before slowly moderating as the upper low drifts
northeast.


Miller/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