RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Mon May 11 16:47:02 UTC 2026.
MD 0704 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE COASTAL CAROLINAS
Mesoscale Discussion 0704
NWS Storm Prediction Center Norman OK
1143 AM CDT Mon May 11 2026
Areas affected...portions of the coastal Carolinas
Concerning...Severe potential...Watch unlikely
Valid 111643Z - 111845Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated to widely scattered thunderstorms may pose a risk
for isolated damaging wind gusts and marginally severe hail this
afternoon across the coastal Carolinas.
DISCUSSION...Isolated convection is ongoing ahead of a weak surface
low analyzed east of Florence, SC, with additional agitated cumulus
noted on the seaward side of the coastal sea breeze across portions
of the Crystal Coast southward to near Charleston, SC. While
mid-level lapse rates remain poor (as sampled by the 12z MHX/CHS
observed soundings), continued diurnal heating amid ample low-level
moisture (dewpoints in the mid-60s to near 70 F) is aiding in weak
destabilization, with latest mesoanalysis and forecast soundings
depicting 500-1000 J/kg MLCAPE. Expectation is for convection to
gradually increase in coverage along the sea breeze and ahead of the
approaching front as lingering inhibition continues to erode.
Strong westerly flow aloft downstream of an approaching upper-level
trough is supporting 35-45+ kts of effective bulk shear, which is
sufficient to promote updraft organization into multicells and
perhaps marginal supercell structures. Some potential for locally
damaging wind gusts and marginally severe hail will accompany more
robust updrafts, with the greatest potential expected on the coastal
side of the sea breeze where greater low-level moisture may favor
locally stronger buoyancy. The given the expectation for the severe
risk to remain limited in magnitude and coverage, watch issuance is
not expected at this time.
..Chalmers/Mosier.. 05/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MHX...ILM...CHS...
LAT...LON 32547991 32628014 32998026 33567976 34247880 34837748
35207647 35357567 35297544 35137541 35007568 34797613
34497645 34537687 34357737 34007770 33757783 33677849
33477885 33147908 32807938 32677963 32547991
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0713 AM CDT Mon May 11 2026
Valid 111300Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE COASTAL
CAROLINAS INTO THE FLORIDA PENINSULA...AND ALONG THE CENTRAL GULF
COAST...
...SUMMARY...
Isolated severe storms with locally damaging wind gusts and hail are
possible Monday afternoon from the coastal Carolinas into the
Florida Peninsula, and along the central Gulf Coast.
...Carolinas...
A large upper trough is present today over the eastern states, with
a weak cold front sagging southward across the Carolinas. Ample
low-level moisture is present to the south of the front from central
SC into southeast NC, with dewpoints in the mid 60s. Pockets of
daytime heating will destabilize this region, with the potential for
isolated thunderstorm development by early afternoon. Low-level
winds are veered and relatively weak, limiting frontal convergence
and shear. A few strong storms may occur with locally gusty winds
and hail. But the overall threat appears marginal.
...Eastern FL...
Warm/moist conditions are expected today over the FL Peninsula with
temperatures over the interior warming into the 90s. Deep westerly
flow will focus convergence along the east-coast sea-breeze, leading
to scattered afternoon thunderstorms. Sufficient deep-layer
vertical shear may result in isolated strong-severe storms producing
gusty/damaging winds and hail.
...Coastal LA/MS/AL...
A convectively-aided shortwave trough over east TX will continue to
track eastward across the central Gulf Coast region today. The
combination of daytime heating and dewpoints in the mid-upper 60s
will yield moderate CAPE values, leading to relatively widespread
afternoon thunderstorms from southeast LA into southern MS/AL.
Low-level winds are weak and lapse rates are rather weak.
Nevertheless, cooler temperatures aloft and degree of instability
will support a risk of occasionally intense cells capable of
damaging winds and hail.
..Hart/Wendt.. 05/11/2026
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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1131 AM CDT Mon May 11 2026
Valid 111630Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE COASTAL
CAROLINAS ITO THE EASTERN FLORIDA PENINSULA...AND ACROSS THE CENTRAL
GULF COAST...
...SUMMARY...
Isolated severe storms with locally damaging wind gusts and hail are
possible this afternoon from the coastal Carolinas into the Florida
Peninsula, and along the central Gulf Coast.
...Synopsis...
Upper pattern across the CONUS this morning consists of western
ridging and eastern troughing. A pair of shortwave troughs are
embedded within the parent trough, one moving through the middle OH
Valley and the other farther south across TX. A convectively
generated vorticity maximum moving across the western Gulf precedes
the TX shortwave. Farther west, a shortwave trough is moving through
the northern periphery of the upper ridging over northern MT and
adjacent southern Saskatchewan.
Recent surface analysis places a low over the eastern NC/SC border
vicinity, with a cold front extending southwestward through the
Southeast and southern AL through the far western Gulf into Deep
South TX. Another low exists farther northwest over southern
Saskatchewan, with a cold front extending south-southwestward from
this low across eastern into south-central MT.
...Eastern SC/Far Southern NC...
Regional radar imagery shows isolated thunderstorms currently
ongoing near the surface low over the eastern NC/SC border vicinity.
A modest increase in buoyancy is anticipated ahead of these storms
over the next few hours. This buoyancy coupled with strong shear
could result in a few bowing segments capable of damaging gusts.
Additional isolated thunderstorm development is anticipated late
this afternoon as the weak cold front moves eastward across SC.
Moderate buoyancy and shear will support the potential for a few
more robust/organized updrafts capable of isolated hail and/or
damaging gusts.
...Eastern FL...
Warm/moist conditions are expected today over the FL Peninsula, with
temperatures over the interior warming into the 90s. Deep westerly
flow will focus convergence along the east-coast sea-breeze, leading
to scattered afternoon thunderstorms. Sufficient deep-layer vertical
shear may result in isolated strong-severe storms producing
gusty/damaging winds and hail.
...Northern/eastern ND into eastern SD...
Despite limited low-level moisture, modest buoyancy may develop late
this afternoon/early this evening amid cooling mid-level
temperatures and increasing mid-level moisture. This buoyancy will
develop atop a deeply mixed boundary layer, supporting the potential
for strong gusts if any updrafts can deepen/mature. Given the weak
and elevated nature of the buoyancy, developing a mature updraft
capable of lightning will be difficult and the current expectation
is for most of this activity to be shallow and non-lightning
producing. That being said, gusty surface winds are possible with
any convection does develop atop the deeply mixed boundary layer.
...Coastal LA/MS/AL...
The convectively generated shortwave trough over the western Gulf
mentioned in the synopsis (and associated surface low) are expected
to progress eastward throughout the day, while the stronger
shortwave trough back across TX also progress east-southeastward.
Easterly/southeasterly low-level flow will be maintained north of
the Gulf low, increasing low-level convergence along the slow-moving
frontal zone. This convergence will be augmented by ascent attendant
to the TX shortwave, with numerous showers and thunderstorms likely.
Poor lapse rates will limit buoyancy, although moderate deep-layer
shear could support a few deeper, more organized updrafts. Primary
risk over this area is heavy rain (as noted in the WPC Day 1
Excessive Rainfall Outlook), but a few water-loaded downbursts
capable of wind damage are possible as well.
..Mosier/Chalmers.. 05/11/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1144 AM CDT Mon May 11 2026
Valid 111700Z - 121200Z
...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN MONTANA INTO
WEST-CENTRAL NORTH DAKOTA...
...Northern and Central Plains...
A deepening lee trough across far eastern MT under a 60-70 knot
mid-level jet will contribute to fire weather concerns across
portions of the northern and central Plains through today. Stronger
south winds of 15-20 mph ahead of the eastward moving surface trough
are occurring over the Dakotas, with latest model guidance
suggesting this steady southerly flow being maintained through the
day. RH is trending lower with potential for broader instances of
20-25% by peak afternoon heating, particularly across eastern ND and
the Red River Valley of the North. Elevated Highlights have been
extended eastward to encompass all of ND and portions of western MN
today.
Farther west in the wake of the departing trough, dry and breezy
conditions including west/northwest winds 20-25 mph combined with
afternoon RH of 15-25% and dry fuels will support Critical fire
weather conditions for portions of northeastern MT into west-central
ND. A slight eastward expansion of Critical Highlights further into
ND was made based on latest surface observation and forecast
guidance trends.
..Williams.. 05/11/2026
.PREV DISCUSSION... /ISSUED 0151 AM CDT Mon May 11 2026/
...Synopsis...
Along the northern periphery of a large-scale ridge centered over
the West, a robust midlevel trough and accompanying 70-kt westerly
jet streak will advance eastward across MT and ND during peak
heating. In the low-levels, a lee trough will extend southward along
the northern/central Plains, before being overtaken by a cold front
during the evening.
...Northern and Central Plains...
Within the base of the midlevel trough, strong deep-layer westerly
flow will overspread the northern High Plains during the day. Here,
downslope flow trajectories and diurnal heating will result in a
deeply mixed boundary layer along/west of the lee trough --
characterized by surface temperatures in the middle/upper 70s and
20-25 percent RH. Despite the somewhat marginal RH reductions,
downward transport of the high-momentum flow and a tight pressure
gradient will contribute to 20-25 mph sustained west-northwesterly
surface winds (with gusts upwards of 35 mph). The greatest overlap
of these strong/gusty winds and low RH atop receptive fuels is
expected over parts of eastern MT into west-central ND -- where
Critical highlights are in place. A north-northwesterly surface wind
shift will accompany the frontal passage during the evening hours,
though substantial post-frontal RH recovery is expected.
Farther south along the lee trough into the central Plains, more
substantial downslope warming/drying will yield temperatures in the
lower/middle 80s and 15-20 percent RH. These warm/dry conditions
combined with around 15 mph sustained west-southwesterly surface
winds will yield elevated to locally critical fire-weather
conditions, given critically dry fuels here as well.
...Please see www.spc.noaa.gov/fire for graphic product...
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