Weather Prediction Center

National Oceanic and Atmospheric Administration

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
347 AM EDT Fri May 03 2024

Valid 12Z Fri May 03 2024 - 12Z Sun May 05 2024

...There is a Slight Risk of excessive rainfall over parts of the
Western/Central Gulf Coast on Friday and the Southern Plains on Saturday...

...Heavy snow over the Sierra Nevada Mountains on Saturday...

...There is a Slight Risk of severe thunderstorms over parts of the
Central/Southern Plains...

A front extending from the Great Lakes to the Southern Plains will slowly
dissipate on Friday while a new front develops over parts of the Central
Plains/Great Basin. Upper-level energy over the Southern Plains/Lower
Mississippi Valley and very moist air will aid in producing showers and
thunderstorms with heavy rain over parts of southeastern Texas and
Louisiana. Therefore, the WPC has issued a Slight Risk (level 2/4) of
excessive rainfall over parts of the Western/Central Gulf Coast through
Saturday morning. The associated heavy rain will create mainly localized
areas of flash flooding, with urban areas, roads, small streams, and
low-lying areas the most vulnerable.

In addition, some of the showers and thunderstorms will be severe.
Therefore, the SPC has issued a Slight Risk (level 2/5) of severe
thunderstorms over parts of the Southern High Plains through Saturday
morning. The hazards associated with these thunderstorms are frequent
lightning, severe thunderstorm wind gusts, hail, and a few tornadoes.
Further, there will be an additional risk of hail two inches or greater
over the area.

Moreover, the developing front over western Kansas will cause a second
area of severe thunderstorms. Therefore, the SPC has issued a Slight Risk
(level 2/5) of severe thunderstorms over parts of the Central High Plains
through Saturday morning. The hazards associated with these thunderstorms
are frequent lightning, severe thunderstorm wind gusts, hail, and a few
tornadoes.

Furthermore, on Friday, showers and thunderstorms will develop along and
ahead of the front extending from the Great Lakes to the Lower Mississippi
Valley. The showers and thunderstorms will march eastward into the Lower
Great Lakes, Central Appalachians, Mid-Atlantic, and Southeast.

By Saturday, the new front will extend from the Upper Great Lakes to the
Southern High Plains. Moisture pooling along the boundary will create
showers and thunderstorms with heavy rain over central Texas and parts of
southeastern Oklahoma. Therefore, the WPC has issued a Slight Risk (level
2/4) of excessive rainfall over parts of the Southern Plains from Saturday
into Sunday morning. The associated heavy rain will create mainly
localized areas of flash flooding, with urban areas, roads, small streams,
and low-lying areas the most vulnerable.

Similarly, some of the showers and thunderstorms will be severe.
Therefore, the SPC has issued a Slight Risk (level 2/5) of severe
thunderstorms over parts of the Southern High Plains from Saturday into
Sunday morning. The hazards associated with these thunderstorms are
frequent lightning, severe thunderstorm wind gusts, hail, and a few
tornadoes. Moreover, there will be an additional risk of hail two inches
or greater over the area. The showers and thunderstorms will also develop
along and ahead of the front from the Great Lakes to the Ohio Valley.

A dissipating front will move over the Appalachians into the Southeast on
Saturday. Rain showers will develop over parts of the Northeast into the
Mid-Atlantic. Additionally, showers and thunderstorms will extend from
parts of the Tennessee Valley to the Southeast.

Meanwhile, upper-level energy over the Northern Rockies will create light
snow over parts of the Northern Rockies and Northern High Plains on
Friday, ending by Friday night. Moreover, a front over the Eastern Pacific
will move onshore over the Pacific Northwest overnight Friday, moving
inland to the Northern Intermountain Region and Southern California by
Sunday morning.

The system will produce rain over parts of the Pacific Northwest Coast
overnight Friday, expanding into Northern California by Saturday morning.
Light snow will develop over parts of the higher elevations of the Pacific
Northwest on Saturday. As the front moves inland, rain expands into
Southern California on Saturday afternoon. Heavy snow will develop over
parts of the Sierra Nevada Mountains overnight Saturday into Sunday. By
Sunday morning, snow will move over parts of the Great Basin.


Ziegenfelder


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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EDT Fri May 3 2024

Valid 12Z Mon May 06 2024 - 12Z Fri May 10 2024


...Northern Plains to Midwest Heavy Rain Threat early next week...


...Overview...

An upper low that is strong for this time of year is forecast to
move through the West by early next week and track/meander into
the Plains and Midwest as the week progresses. This will support
cooler than normal temperatures, gusty winds, and precipitation
including higher elevation snow in the West early in the week. Rain
that could be locally heavy shifts into the northern Plains and
downstream through the Midwest. Meanwhile farther south, mean upper
ridging will lead to warming pre-frontal temperatures for much of
the central and eastern U.S. that could yield some record values.
Upstream, Pacific upper trough energy will work inland over an
unsettled West and to the south-central U.S.. This may interact
with a wavy and stalling lead front and combine with pooling
moisture and instability to fuel rain and thunderstorms over the
south-central states/Mid-South and onward into later next week,
still also under some influence from the lead upper low/trough.

...Guidance/Predictability Assessment...

Model and ensemble solutions overall seem reasonably clustered for
Monday-Wednesday and generally in step with National Blend of
Models (NBM) guidance. This bolsters forecast confidence in a
composite GFS/ECMWF/UKMET/Canadian model blend to provide maximum
system detail as consistent with feature predictability. Opted to
switch preference to a composite of best clustered GFS/ECMWF and
GEFS/ECMWF ensemble means along with the NBM for later next week
to temper detail some, acting to mitigate growing but managebale
forecast spread. WPC product continuity is decently maintained in
this manner. Latest 00 UTC guidance has mainly stayed in line.

...Weather/Hazards Highlights...

As a main/closed upper low tracks out of the West as addiitonal
energies feed back through the West Coast, widespread precipitation
will include some enhanced snow potential given cooled
temperatures. The higher elevations of the Sierra Nevada, north
into the Cascades, and east into the Intermountain West/Rockies
will see May snow. Troughs/low aloft and frontal boundaries could
also produce some high winds across the Great Basin to Rockies to
High Plains. Precipitation is forecast to move steadily eastward
through early next week, reaching the northern Plains to Midwest
Monday and Tuesday. Rainfall on the west side of the strong surface
low could be heavy across eastern Montana into the Dakotas given
strong upper-level support for lift. However, this region is not
particularly sensitive to flooding concerns, and instability should
be limited wrapping around the low. A WPC Excessive Rainfall
Outlook (ERO) Marginal Risk area remains in place in the Day
4/Monday and into Day 5/Tuesday for this area given the potential
for protracted heavy rain, but likely without widespread
significant flooding impacts. The Marginal Risk extends southeast
into the Upper/Mid-Mississippi Valley, where more instability will
be in place for higher rain rates, but storms will likely be
faster moving. The Storm Prediction Center also has portions of the
Plains delineated with potential for severe weather on Monday.
Convective rainfall is forecast to shift east into the Great Lakes
and Ohio Valley Tuesday into Wednesday with system progression and
intercecting return flow. A Day5 Marginal Risk ERO was introduced.

Upstream, aforementioned Pacific upper trough energy will work
inland over an unsettled West and over the south-central U.S. into
later next week, riding under the base of the lingering main upper
low/trough. These will interact with wavy and stalling fronts and
combine with pooling moisture and instability to fuel a favorable
pattern for rain and thunderstorms across the south-central
states/Mid-South and onward to the East where downstream energy
track may support moderate late next week coastal low development.

Much cooler than average maximum temperatures will slowly moderate
while spreading next week from the West to the northern Plains
with slow ejection of a closed upper low. But farther southeast,
mean upper ridging will meanwhile spread quite warm pre-frontal
temperatures from the South through the Appalachians/Mid-Atlantic
to threaten record seasonal values. 90s are forecast to become
more widespread across the southern tier, with temperatures over
100F (and even higher heat indices) into south Texas and the
possibility for the first excessive heat days of the year.

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 (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
325 AM EDT Fri May 03 2024

Valid 00Z Sat May 04 2024 - 00Z Sat May 11 2024

Surface highs strengthening and consolidating to the north of
Hawaii will favor breezy to locally strong trade flow through the
weekend into early next week. Meanwhile model guidance remains in
fairly good agreement and a favored composite shows a mid-upper
trough/low centered west of Hawaii late week and then coming
overhead by early next week. This could provide some instability
for increased showers, which would favor windward and mauka areas
given the increasing trades. Slightly above average moisture
anomalies may peak around Monday-Tuesday. Rainfall totals do not
appear to be significantly high though. This wet trade wind
pattern looks to continue into much of next week, though trades
may decrease slightly later next week.

Schichtel

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
500 AM EDT Fri May 3 2024
Day 1
Valid 12Z Fri May 03 2024 - 12Z Sat May 04 2024

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE GULF COAST AND SOUTHERN PLAINS...

...West Texas to Gulf Coast into Tennessee Valley...
Main concern for excessive rainfall today will be along the Gulf
coast due to one or more rounds of thunderstorms over region that
has become water- logged recently. Of most immediate concern is how
much convection that developed overnight in eastern Texas will
persist into the Day 1 period at 12Z and how much of an overlap
will there be with parts of the state that received 2 to 5 inches
of rain in the previous 24 hours and 5 to 10 inches of rain since
early this week. With cloud tops still cooling as of 08Z...the
expectation is that some areas of higher intensity rainfall will
still be occurring at 12Z with the concern for the rainfall to
exacerbate on-going flooding and for the additional rain to push
some areas into flood. However...weaker instability immediately
downstream and the progressive nature of the convection should lead
to weakening rainfall rates during the morning. The 03/00Z suite
of guidance has continued the idea from earlier runs that focus any
convection that forms later today or this evening will be shifting
either east with a mid-level trough or shifting out west near the
dryline. As a result...opted to propagate the Slight Risk area from
the Day 2 period into todays Day 1 outlook period rather than
issue a focused, short term extension of the Moderate risk after
collaboration with HGX/SHV. Maintained a Marginal Risk area farther
eastward from the Gulf coast towards the Tennessee Valley as the
mid-level trough propagates into better instability and out in West
Texas near the dryline.

...Western High Plains...
A fairly robust mid-level perturbation will eject east-southeast
out of WY/CO with convection initiating over the Front Range,
potentially developing into a MCS as it migrates eastward through
southern NE into KS. Models are in agreement of at least some
modest QPF with 1-2" scattered across the aforementioned areas.
Present indications are that the convection looks to be progressive
enough over areas with sufficiently high flash flood guidance that
a Marginal Risk area still adequately covers the risk.


...West Aspect of the Appalachians... Showers capable of producing
locally intense downpours will be moving towards parts of the
Appalachians/far eastern Ohio Valley later today. Given 3-hour
Flash Flood Guidance around 1.5 inches per hour...and some ensemble
guidance suggesting an inch of rain in the outlook area was
possible...maintained the previously issued Marginal Risk area
although spaghetti plots of QPF showed more enthusiasm for 2 inch
amounts from the ARW core.


Bann

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
500 AM EDT Fri May 3 2024
Day 2
Valid 12Z Sat May 04 2024 - 12Z Sun May 05 2024

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PARTS OF THE
WESTERN AND SOUTHERN HIGH PLAINS...

Height falls aloft ejecting eastward from the Southern Rockies and
the presence of a dryline over West Texas will foster an
environment for thunderstorms capable of producing heavy rainfall
by later in the day on Saturday that persists into Saturday
night/early Sunday morning. Precipitable water values will have
increased to nearly 1,5 inches...some 2 to 2.5 standardized
anomalies greater than climatology...over portions of central and
west central Texas by 00Z Sunday in response to a period of
southeasterly flow off of the Gulf of Mexico. Consensus of model
guidance QPF in the range of 1 to 3 inches seems
reasonable...although the UKMET was a notable outlier.

...Northern Sierra Nevada Foothills...

A fairly robust IVT pulse will slide down the west coast with
southwesterly flow aimed orthogonally to the northern and central
Sierra's by Saturday. Higher elevations will be greeted with more
snow, but the adjacent foothills will remain warm enough to benefit
from all rainfall. Rates will be borderline overall, but the
prospects for over 1" of precip has grown in the past succession
of runs with the ensemble bias corrected guidance now upwards of 2"
now forecast within the elevations below 8000' MSL, falling mainly
in a span of 8-12 hours. The threat is on the lower end of MRGL. Maintained
continuity from previous forecast and will assess whether it needs
adjusting, or removal pending future trends in guidance.

Bann

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
500 AM EDT Fri May 3 2024
Day 3
Valid 12Z Sun May 05 2024 - 12Z Mon May 06 2024

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER THE SOUTHERN
PLAINS...

The potential for excessive rainfall makes its way eastward on
Sunday in association with a closed low aloft and a cold front at
the surface. Model QPF was not as heavy as forecast on Day 2 as
shifting low level flow results in weaker low level moisture flux
convergence along the front. Despite model QPF generally being 2
inches or less...opted for a Slight Risk given the wet antecedent
conditions over portions of eastern Texas and eastern Oklahoma.

Bann

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EDT Fri May 3 2024


As a main/closed upper low tracks out of the West as addiitonal
energies feed back through the West Coast, widespread precipitation
will include some enhanced snow potential given cooled
temperatures. The higher elevations of the Sierra Nevada, north
into the Cascades, and east into the Intermountain West/Rockies
will see May snow. Troughs/low aloft and frontal boundaries could
also produce some high winds across the Great Basin to Rockies to
High Plains. Precipitation is forecast to move steadily eastward
through early next week, reaching the northern Plains to Midwest
Monday and Tuesday. Rainfall on the west side of the strong surface
low could be heavy across eastern Montana into the Dakotas given
strong upper-level support for lift. However, this region is not
particularly sensitive to flooding concerns, and instability should
be limited wrapping around the low. A WPC Excessive Rainfall
Outlook (ERO) Marginal Risk area remains in place in the Day
4/Monday and into Day 5/Tuesday for this area given the potential
for protracted heavy rain, but likely without widespread
significant flooding impacts. The Marginal Risk extends southeast
into the Upper/Mid-Mississippi Valley, where more instability will
be in place for higher rain rates, but storms will likely be
faster moving. The Storm Prediction Center also has portions of the
Plains delineated with potential for severe weather on Monday.
Convective rainfall is forecast to shift east into the Great Lakes
and Ohio Valley Tuesday into Wednesday with system progression and
intercecting return flow. A Day5 Marginal Risk ERO was introduced.

Upstream, aforementioned Pacific upper trough energy will work
inland over an unsettled West and over the south-central U.S. into
later next week, riding under the base of the lingering main upper
low/trough. These will interact with wavy and stalling fronts and
combine with pooling moisture and instability to fuel a favorable
pattern for rain and thunderstorms across the south-central
states/Mid-South and onward to the East where downstream energy
track may support moderate late next week coastal low development.

Much cooler than average maximum temperatures will slowly moderate
while spreading next week from the West to the northern Plains
with slow ejection of a closed upper low. But farther southeast,
mean upper ridging will meanwhile spread quite warm pre-frontal
temperatures from the South through the Appalachians/Mid-Atlantic
to threaten record seasonal values. 90s are forecast to become
more widespread across the southern tier, with temperatures over
100F (and even higher heat indices) into south Texas and the
possibility for the first excessive heat days of the year.

Schichtel

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EDT Fri May 3 2024


As a main/closed upper low tracks out of the West as addiitonal
energies feed back through the West Coast, widespread precipitation
will include some enhanced snow potential given cooled
temperatures. The higher elevations of the Sierra Nevada, north
into the Cascades, and east into the Intermountain West/Rockies
will see May snow. Troughs/low aloft and frontal boundaries could
also produce some high winds across the Great Basin to Rockies to
High Plains. Precipitation is forecast to move steadily eastward
through early next week, reaching the northern Plains to Midwest
Monday and Tuesday. Rainfall on the west side of the strong surface
low could be heavy across eastern Montana into the Dakotas given
strong upper-level support for lift. However, this region is not
particularly sensitive to flooding concerns, and instability should
be limited wrapping around the low. A WPC Excessive Rainfall
Outlook (ERO) Marginal Risk area remains in place in the Day
4/Monday and into Day 5/Tuesday for this area given the potential
for protracted heavy rain, but likely without widespread
significant flooding impacts. The Marginal Risk extends southeast
into the Upper/Mid-Mississippi Valley, where more instability will
be in place for higher rain rates, but storms will likely be
faster moving. The Storm Prediction Center also has portions of the
Plains delineated with potential for severe weather on Monday.
Convective rainfall is forecast to shift east into the Great Lakes
and Ohio Valley Tuesday into Wednesday with system progression and
intercecting return flow. A Day5 Marginal Risk ERO was introduced.

Upstream, aforementioned Pacific upper trough energy will work
inland over an unsettled West and over the south-central U.S. into
later next week, riding under the base of the lingering main upper
low/trough. These will interact with wavy and stalling fronts and
combine with pooling moisture and instability to fuel a favorable
pattern for rain and thunderstorms across the south-central
states/Mid-South and onward to the East where downstream energy
track may support moderate late next week coastal low development.

Much cooler than average maximum temperatures will slowly moderate
while spreading next week from the West to the northern Plains
with slow ejection of a closed upper low. But farther southeast,
mean upper ridging will meanwhile spread quite warm pre-frontal
temperatures from the South through the Appalachians/Mid-Atlantic
to threaten record seasonal values. 90s are forecast to become
more widespread across the southern tier, with temperatures over
100F (and even higher heat indices) into south Texas and the
possibility for the first excessive heat days of the year.

Schichtel

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
310 AM EDT Fri May 3 2024

Valid 12Z Fri May 03 2024 - 12Z Mon May 06 2024

...Cascades through Sierra Nevada and Intermountain West...
Days 2-3...

An upper low will continue to deepen as it drops southeast from
the Gulf of Alaska and across the northeastern Pacific today,
reaching the Pacific Northwest tonight. Models continue to
advertise an anomalously deep system for early May, with 500mb
heights dropping 2-3 standard deviations below normal across Oregon
and northern California as the system moves onshore. This system
will bring widespread precipitation and windy conditions across the
region, beginning in the Pacific Northwest and northwestern
California tonight, before spreading further south and east on
Saturday. As snow levels drop below 5000ft from the southern
Cascades to the northern Sierra, impactful accumulations are
expected in the higher terrain on Saturday. The heaviest amounts
are most likely to fall along the Sierra Nevada, where left-exit
region upper jet forcing in addition to strong upslope flow are
expected to help bolster rates. WPC PWPF shows high probabilities
for 8 inches or more falling along the northern to central Sierra
in areas above 5000ft on Saturday. Heavier accumulations of 1-2ft
can be expected across some of the higher peaks. In addition to the
falling snow, gusty winds and blowing snow are forecast to
contribute to moderate winter storm impacts as indicated by the
WSSI.

The system is forecast to gradually weaken and transition to an
open wave as it swings east across the Great Basin into the central
Rockies on Sunday into early Monday. Widespread heavy snow
accumulations are not expected, although some portions of the Great
Basin into the Rockies could see some locally heavy totals. This
includes the eastern Oregon, northern Nevada, and northern Utah
mountains.

The probability of significant icing is less than 10 percent.

Pereira

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EDT Fri May 3 2024

Valid 12Z Mon May 06 2024 - 12Z Fri May 10 2024


...Northern Plains to Midwest Heavy Rain Threat early next week...


...Overview...

An upper low that is strong for this time of year is forecast to
move through the West by early next week and track/meander into
the Plains and Midwest as the week progresses. This will support
cooler than normal temperatures, gusty winds, and precipitation
including higher elevation snow in the West early in the week. Rain
that could be locally heavy shifts into the northern Plains and
downstream through the Midwest. Meanwhile farther south, mean upper
ridging will lead to warming pre-frontal temperatures for much of
the central and eastern U.S. that could yield some record values.
Upstream, Pacific upper trough energy will work inland over an
unsettled West and to the south-central U.S.. This may interact
with a wavy and stalling lead front and combine with pooling
moisture and instability to fuel rain and thunderstorms over the
south-central states/Mid-South and onward into later next week,
still also under some influence from the lead upper low/trough.

...Guidance/Predictability Assessment...

Model and ensemble solutions overall seem reasonably clustered for
Monday-Wednesday and generally in step with National Blend of
Models (NBM) guidance. This bolsters forecast confidence in a
composite GFS/ECMWF/UKMET/Canadian model blend to provide maximum
system detail as consistent with feature predictability. Opted to
switch preference to a composite of best clustered GFS/ECMWF and
GEFS/ECMWF ensemble means along with the NBM for later next week
to temper detail some, acting to mitigate growing but managebale
forecast spread. WPC product continuity is decently maintained in
this manner. Latest 00 UTC guidance has mainly stayed in line.

...Weather/Hazards Highlights...

As a main/closed upper low tracks out of the West as addiitonal
energies feed back through the West Coast, widespread precipitation
will include some enhanced snow potential given cooled
temperatures. The higher elevations of the Sierra Nevada, north
into the Cascades, and east into the Intermountain West/Rockies
will see May snow. Troughs/low aloft and frontal boundaries could
also produce some high winds across the Great Basin to Rockies to
High Plains. Precipitation is forecast to move steadily eastward
through early next week, reaching the northern Plains to Midwest
Monday and Tuesday. Rainfall on the west side of the strong surface
low could be heavy across eastern Montana into the Dakotas given
strong upper-level support for lift. However, this region is not
particularly sensitive to flooding concerns, and instability should
be limited wrapping around the low. A WPC Excessive Rainfall
Outlook (ERO) Marginal Risk area remains in place in the Day
4/Monday and into Day 5/Tuesday for this area given the potential
for protracted heavy rain, but likely without widespread
significant flooding impacts. The Marginal Risk extends southeast
into the Upper/Mid-Mississippi Valley, where more instability will
be in place for higher rain rates, but storms will likely be
faster moving. The Storm Prediction Center also has portions of the
Plains delineated with potential for severe weather on Monday.
Convective rainfall is forecast to shift east into the Great Lakes
and Ohio Valley Tuesday into Wednesday with system progression and
intercecting return flow. A Day5 Marginal Risk ERO was introduced.

Upstream, aforementioned Pacific upper trough energy will work
inland over an unsettled West and over the south-central U.S. into
later next week, riding under the base of the lingering main upper
low/trough. These will interact with wavy and stalling fronts and
combine with pooling moisture and instability to fuel a favorable
pattern for rain and thunderstorms across the south-central
states/Mid-South and onward to the East where downstream energy
track may support moderate late next week coastal low development.

Much cooler than average maximum temperatures will slowly moderate
while spreading next week from the West to the northern Plains
with slow ejection of a closed upper low. But farther southeast,
mean upper ridging will meanwhile spread quite warm pre-frontal
temperatures from the South through the Appalachians/Mid-Atlantic
to threaten record seasonal values. 90s are forecast to become
more widespread across the southern tier, with temperatures over
100F (and even higher heat indices) into south Texas and the
possibility for the first excessive heat days of the year.

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 (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