WW 543 SEVERE TSTM DE MD NJ PA CW 081710Z - 082200Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 543
NWS Storm Prediction Center Norman OK
110 PM EDT Sat Aug 8 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Delaware
Eastern Maryland
Southern New Jersey
Southeast Pennsylvania
Coastal Waters
* Effective this Saturday afternoon and evening from 110 PM until
600 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...A cluster of thunderstorms will track eastward across the
watch area this afternoon, posing a risk of locally damaging wind
gusts.
The severe thunderstorm watch area is approximately along and 55
statute miles north and south of a line from 35 miles southwest of
Wilmington DE to 20 miles east southeast of Atlantic City NJ. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
27030.
...Hart
WW 0543 Status Updates
STATUS FOR WATCH 0543 HAS NOT BEEN ISSUED YET
MD 1863 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN MID-ATLANTIC INTO PARTS OF SOUTHERN NEW ENGLAND
Mesoscale Discussion 1863
NWS Storm Prediction Center Norman OK
1211 PM CDT Sat Aug 08 2026
Areas affected...Northern Mid-Atlantic into parts of southern New
England
Concerning...Severe potential...Watch possible
Valid 081711Z - 081845Z
Probability of Watch Issuance...40 percent
SUMMARY...Thunderstorm development is likely within the next 1-2
hours. The strongest storms will be capable of wind damage. Given
the expected scattered storm coverage a watch is possible this
afternoon.
DISCUSSION...Showers/towering cumulus have been deepening over the
past hour near Binghamton. With a modest shortwave trough in the
lower Great Lakes, the expectation is for this activity to continue
and intensify into the mid/late afternoon. Heating within
southeastern New York into southern New England will steepen
low-level lapse rates. Modest deep-layer shear will allow for some
organization, though a cluster/linear mode will be most likely. The
strongest activity will be capable of wind damage. Trends in CAM
guidance continue to suggest this region will see greater
clustering/storm coverage. A watch is possible this afternoon.
..Wendt/Hart.. 08/08/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BOX...OKX...ALY...BGM...
LAT...LON 41827305 41657396 41657405 41457529 41397600 41747630
42167618 42777582 42967393 42907341 42727283 41997283
41827305
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MD 1862 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL MARYLAND INTO SOUTHERN NEW JERSEY
Mesoscale Discussion 1862
NWS Storm Prediction Center Norman OK
1055 AM CDT Sat Aug 08 2026
Areas affected...Central Maryland into southern New Jersey
Concerning...Severe potential...Watch unlikely
Valid 081555Z - 081730Z
Probability of Watch Issuance...20 percent
SUMMARY...A line of thunderstorms may produce isolated wind damage,
particularly as it nears the coast where the environment is more
favorable. The need for a watch is not certain in the short term,
but trends will be monitored.
DISCUSSION...A loosely organized line of convection moving around 35
kt to the east has shown modest signs of intensification/deepening
per MRMS CAPPI data. A recent observation from Martinsburg, WV had a
40 kt wind gust as the line moved through. KLWX radar velocity also
suggests a slight enhancement to inbound velocities along the
southern flank of the line. The morning observed IAD sounding had a
dry pocket at low levels which has contributed to remaining MLCIN
thus far. Closer to the coast, temperatures have been warming into
the mid/upper 80s F and inhibition should be weaker there. It is
possible that some increase in strong/damaging wind potential may
occur as this line moves east early this afternoon. The main
question is how widespread this threat will be. A watch is not
anticipated in the short term, but observational trends will be
monitored.
..Wendt/Hart.. 08/08/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...CTP...LWX...
LAT...LON 39217785 39327805 39897740 40187693 40127489 39907445
39437467 39097532 39217785
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0743 AM CDT Sat Aug 08 2026
Valid 081300Z - 091200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
PARTS OF THE MID-ATLANTIC INTO SOUTHERN PORTIONS OF THE NORTHEAST...
...SUMMARY...
Scattered strong to severe thunderstorms capable primarily of
damaging gusts will be possible today across the Mid-Atlantic states
into southern New England.
...Mid-Atlantic states into southern New England...
Satellite imagery this morning indicates a weak disturbance moving
east across the Lower Great Lakes, with early morning
showers/thunderstorms from WV/PA into western NY likely associated
with this feature. Strong heating from Chesapeake Bay northward
into southern portions of the Northeast will yield around 2000 J/kg
MLCAPE by early afternoon. Of particular note is seemingly adequate
strength of flow between 700-250 mb for organized line segments.
Given the relatively high PW environment (1.75-2.0 inches),
expecting a few clusters to evolve this afternoon with an attendant
risk for strong to locally severe gusts (50-65 mph). Have
expanded/increased severe-wind probabilities into southern New
England and southward into the Chesapeake Bay vicinity. Marginally
severe hail may also occur with the stronger cells before excessive
outflow leads to more linear structures as this activity pushes east
towards the coast by the early evening.
...Northern/Central Plains into MN/IA/MO...
Radar/satellite mosaic shows a cluster of strong to locally severe
thunderstorms over the NE Sandhills this morning. This activity may
continue southeast this morning but weaken as it moves across
central NE. Above average uncertainty/low confidence for this
forecast is due in part to weak to negligible forcing features and
large model spread on potential evolution of isolated to widely
scattered storms later today into tonight. Nonetheless, a strongly
unstable airmass is forecast to develop by early afternoon across
much of the region with 60s to lower 70s boundary layer dewpoints
beneath steep 700-500 mb lapse rates.
Several areas of convection may develop during the late
afternoon/evening near the surface trough, and overnight near the
southward-sagging surface front. Weak convergence along early day
outflow may rejuvenate convection or lead to additional isolated
storms over southern NE into northern KS. This may also coincide
with an increasing low-level jet across the central Plains during
the evening into the overnight, but capping will likely limit storm
coverage except perhaps near a southward-sagging surface front near
the ND/SD border and with warm advection over southern MN into IA.
Large hail and severe gusts will be possible with the more intense
thunderstorms.
Additional high-based convection is possible across eastern CO and
western KS/NE. A hot and well mixed boundary layer will probably
support isolated severe gusts.
...AZ...
Easterly midlevel flow will persist on the southern periphery of an
upper high over the Four Corners. Steep midlevel lapse rates and
persistent moisture across the region will foster thunderstorm
development across the higher terrain during the evening. The hot
and well mixed boundary layer will support strong outflow gusts as
convection moves westward off higher terrain toward the lower
deserts.
..Smith/Kerr.. 08/08/2026
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1105 AM CDT Sat Aug 08 2026
Valid 081630Z - 091200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
VIRGINIA INTO SOUTHEAST NEW YORK AND WESTERN MASSACHUSETTS....
...SUMMARY...
Scattered strong to severe thunderstorms capable primarily of
damaging gusts will be possible today from the Mid-Atlantic states
into southwest New England.
...Northeast States...
Morning water vapor imagery shows a low-amplitude shortwave trough
over OH tracking eastward. A warm/moist air mass is present ahead of
the trough, with pockets of MLCAPE over 2000 J/kg expected later
today. Large scale forcing associated with the trough is rather
weak, and overall coverage of storms may be rather isolated.
However, stronger winds aloft than yesterday suggest a conditional
risk of wind damage with any sustained storm later today. Have
extended the SLGT risk area a little farther north into NY/MA where
morning model guidance suggests higher coverage/confidence in
storms. Have also extended the MRGL farther west into OH beneath
the upper trough where widely scattered storms may also produce
gusty/damaging winds.
...Western NC...
A few afternoon thunderstorms are expected to form off the mountains
of western NC and vicinity, and track slowly southeastward. Strong
daytime heating, humid conditions, and sufficient CAPE may promote a
risk of gusty/damaging winds in the strongest cores.
...North TX...
Isolated thunderstorms are expected to form along an E-W axis across
north TX this afternoon in a hot/humid air mass. The strongest of
these slow-moving cells may produce damaging winds.
...NE/KS...
A cluster of strong thunderstorms is ongoing over central NE. This
activity may persist into the afternoon, tracking southeastward
toward northeast KS/northwest MO. Given the corridor of high CAPE
in this zone, a few strong/severe storms capable of damaging winds
and hail are possible.
...ND/SD/MN/IA...
A strengthening southerly low-level jet will likely lead to
scattered thunderstorms tonight after midnight over central ND.
These storms are expected to develop southeastward into parts of
SD/MN/IA before 12z. Relatively strong vertical shear will support
supercells capable of hail and damaging winds.
...AZ...
Full sunshine and sufficient CAPE will once again promote
thunderstorm develop off the Mogollon Rim this afternoon and
evening. Forecast soundings show increasing mid-level moisture
through the evening as an upper trough passes to the south, perhaps
aiding convective maintenance westward into the lower elevations.
If so, given the favorable steering flow, strong/severe outflow
winds could spread into the PHX area around 00z. This scenario will
be monitored for a possible upgrade to SLGT in later outlooks.
..Hart/Weinman.. 08/08/2026
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1137 AM CDT Sat Aug 08 2026
Valid 081700Z - 091200Z
Minor adjustments were made to the risk areas based on updated
guidance; otherwise, the forecast remains on track. A passing
mid-level wave will contribute to the flattening of the upper ridge
over the northwestern CONUS, promoting areas of stronger flow aloft.
Expansive elevated fire weather conditions are expected as deeper
mixing and terrain-enhanced flow promote wind gusts of 25+ mph and
RH values of 5-15%. The fuelscape across the Pacific Northwest,
Northern Rockies, and northern Plains remains very dry and
increasingly receptive, as depicted by numerous wildfires across
these regions.
Farther south, mixed wet/dry thunderstorms are expected this
afternoon along the northern fringe of advecting monsoonal moisture.
Satellite imagery portrays lingering cloud cover across portions of
the Great Basin and residual smoke in Utah, which may limit some
instability. However, prolonged hot, dry, and unstable conditions
ahead of the monsoonal surge should result in at least some dry
thunderstorm potential where receptive fuels exist.
Across the southern High Plains, daytime high temperatures will
approach 100+ degrees while sustained south/southwesterly winds
increase to 15-20 mph and RH values decline to less than 15%. These
meteorological conditions support a region of Elevated highlights,
though a mixed fuelscape of live fuels and areas of grass curing (as
seen by a 30-day NDVI comparison) and fuels rebounding from spotty
recent rainfall yield a complicated environment. Nonetheless, fire
concerns remain across the risk area.
..Elizalde-Garcia.. 08/08/2026
.PREV DISCUSSION... /ISSUED 0102 AM CDT Sat Aug 08 2026/
...Synopsis...
A large mid-level ridge will remain centered near the Four Corners
region of the US today, with the strongest mid-level flow across the
CONUS once again found along the US-Canadian border. A weak
mid-level vorticity maximum will move across the Pacific Northwest,
however mid-level flow enhancement looks modest with this feature. A
weak lower-level wave will move east from the central Rockies into
the central Plains, bringing with it a belt of modest southwesterly
low-level flow. At the same time, monsoonal moisture will continue
to advance northward across the West, bringing with it chances of
afternoon thunderstorms atop a very dry boundary layer.
... Northern Intermountain West and Pacific Northwest ...
Most of the region will see the development of surface winds around
15 mph with higher gusts as diurnal heating and the associated deep
vertical mixing bring down modest mid-level flow. The deep mixing
will also contribute to relative humidity falling to perhaps as low
as 5% in favored areas across the region, with minimum afternoon
relative humidity between 10-15% elsewhere. Given very receptive
fuels, elevated to locally critical fire weather conditions are
likely.
... California Sierras, Southern/Central Nevada, and much of Utah
...
Similar to Friday, thunderstorms are expected along the western
periphery of a mid-level ridge where the advancing mid- and
upper-level monsoonal moisture will be found. Beneath this moist
plume, a very dry sub-cloud layer will support significant
evaporation of falling precipitation leading to little, if any,
appreciable rainfall. Evaporative cooling beneath these dry
thunderstorms will result in gusty/erratic thunderstorm outflows.
... High Plains of southeast Colorado, southwest Kansas, far
northeast New Mexico, and the western Oklahoma Panhandle ...
Model guidance is in good agreement with a belt of modest
southwesterly 700-millibar flow stretching from southeast Colorado
toward the Great Lakes. This flow should easily mix down to the
surface during the afternoon as strong diurnal heating mixes into
and through this layer. The result will be gusty surface winds
between 15-20 in the presence of minimum relative humidity falling
into the teens. Seasonally adjusted ERC percentiles show a very dry
fuelscape, with percentiles between 95-98%. A small elevated area
was introduced to cover this potential.
...Please see www.spc.noaa.gov/fire for graphic product...
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