No watches are valid as of Mon Apr 14 18:21:02 UTC 2025.MD 0448 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF THE MIDDLE/UPPER OHIO RIVER VALLEY TO THE CENTRAL APPALACHIANS.
Mesoscale Discussion 0448
NWS Storm Prediction Center Norman OK
0118 PM CDT Mon Apr 14 2025
Areas affected...Portions of the Middle/Upper Ohio River Valley to
the Central Appalachians.
Concerning...Severe potential...Watch likely
Valid 141818Z - 142015Z
Probability of Watch Issuance...80 percent
SUMMARY...Severe storms capable of producing large hail and damaging
wind gusts will spread eastward through the afternoon into the
evening. A watch will likely be issued within an hour or two for
parts of the area.
DISCUSSION...Initial thunderstorms are developing across southern IN
this afternoon, generally focused along/ahead of an eastward-moving
cold front. Ahead of this activity, continued diurnal heating amid
increasing boundary-layer moisture (middle/upper 50s to lower 60s
dewpoints) will continue to erode inhibition and support additional
storm development. Steep midlevel lapse rates (sampled by earlier
12Z soundings) atop the destabilizing boundary layer will yield
around 1500 J/kg MLCAPE, favoring a gradual increase in storm
intensity through the afternoon. As 60+ kt of midlevel flow (sampled
by upstream VWP data) overspreads the warm sector, very long/mostly
straight hodographs (60-70 kt of effective shear) will promote
splitting supercell structures, posing a risk of large hail and
damaging wind gusts. Despite the expectation for an initially
semi-discrete mode, strong outflow amid the splitting storm
structures will favor gradual upscale growth into small lines and
clusters with eastward extent -- with an associated increasing
severe-wind risk. A watch will likely be issued for parts of the
area within an hour or two.
..Weinman/Mosier.. 04/14/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...MRX...JKL...ILN...
LMK...
LAT...LON 38248556 38918470 39248402 39638285 40028068 39977973
39747915 39357876 38847859 38237864 37707920 37408001
37228138 37038395 37138489 37338555 37818577 38248556
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
MD 0447 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF CNTRL/SERN SD...SWRN MN...NERN IA...NERN NE
Mesoscale Discussion 0447
NWS Storm Prediction Center Norman OK
0110 PM CDT Mon Apr 14 2025
Areas affected...parts of cntrl/sern SD...swrn MN...nern IA...nern
NE
Concerning...Severe potential...Watch unlikely
Valid 141810Z - 142115Z
Probability of Watch Issuance...5 percent
SUMMARY...Showers spreading southeastward through the mid Missouri
Valley may begin to intensify by 3-4 PM CDT, with a few weak
thunderstorms developing and posing increasing potential for strong
to severe surface gusts while spreading southeastward through the
remainder of the afternoon.
DISCUSSION...In the wake of a deep cyclone, now migrating northeast
of the Upper Great Lakes region, downward mixing of momentum is
already contributing to 30-35+ kt northwesterly surface gusts across
much of the middle Missouri Valley, as boundary-layer warming
progresses. This is occurring just ahead of a vigorous short wave
trough now digging through the western Dakotas, and forecast to
continue rapidly southeastward through early evening.
Models indicate that the mid-level cold core (including -30 to -35C
around 500 mb) will overspread a corridor from central South Dakota
through northeastern Iowa between 20-23Z, coincident with further
strengthening of northwesterly flow (35-40+ kt) in the 850-700 mb
layer and peak afternoon surface heating. As this occurs, forecast
soundings indicate that profiles will become increasingly conducive
to deepening convection capable of producing lightning.
With at least some further intensification of ongoing developing
convection, evaporative cooling and melting of precipitation within
an increasing well-mixed boundary layer (characterized by sizable
surface temperature/dew point spreads on the order of 20+ F),
coupled with the downward mixing of stronger flow aloft, seems
likely to contribute to increasing potential for surface gusts
approaching or briefly exceeding severe limits. This may continue
into early evening, as convection spreads southeastward, before
rapidly diminishing with the onset of boundary-layer cooling.
..Kerr/Mosier.. 04/14/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...DMX...FSD...OAX...ABR...UNR...
LAT...LON 44969838 44749683 43839520 43419469 42209542 42309648
42919815 43719996 44779996 44969838
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
SPC 1630Z Day 1 Outlook
 Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1130 AM CDT Mon Apr 14 2025
Valid 141630Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS WEST
VIRGINIA AND NORTHWEST VIRGINIA...
...SUMMARY...
Scattered strong to severe storms are expected this afternoon
through early tonight from the Upper Ohio Valley eastward to the
Mid-Atlantic. Large hail, severe wind gusts, and a couple of
tornadoes will be possible.
...Upper OH Valley this afternoon into VA early tonight...
Recent satellite imagery depicts a maturing mid-latitude cyclone
moving eastward across Lake Superior towards northeastern Ontario
with an upstream shortwave trough moving through the northern
Plains. Expectation is for the cyclone to continue
deepening/maturing as it moves into and through northeastern Ontario
today, while the upstream shortwave progresses quickly southeastward
through the Mid MO Valley and into the Mid MS Valley. As this
occurs, strong mid-level flow will spread eastward across the OH
Valley and over the Northeast and Mid-Atlantic States.
At the same time, a cold front will spread eastward across the OH
Valley this afternoon and evening, and across the central
Appalachians tonight. Current surface analysis reveals upper 40s to
low 50s dewpoints ahead of the front in the Middle OH Valley, with
the upper 50s/low 60s dewpoints farther southwest over western KY.
This greater low-level moisture is expected to surge northeastward
amid the moderate southwesterly low-level flow, combining with
evapotranspiration to bring upper 50s dewpoints into upper OH Valley
ahead of the front.
This increase in low-level moisture combined with daytime heating
should be enough to destabilize the airmass ahead of the front
across the Upper OH Valley. Forcing for ascent (from a combination
of increasing large-scale ascent and forcing along the front) will
increase across this destabilized area, supporting thunderstorm
development during the afternoon. An initially cellular mode is
anticipated, with steep mid-level lapse rates and long hodographs
potentially resulting in a few supercells. Primary severe risk with
these supercells is large hail of 1-2 inches in diameter. Some
damaging gusts and a tornado or two are possible, although the lack
of higher low-level moisture will mitigate the overall tornado
potential. Strong outflow and increasing mid-level flow suggest a
transition to a more linear mode is likely, with several bowing
segments possible. There is also some potential for the development
of a singular, more coherent convective line. In either case, a
transition from hail to damaging gusts as the primary severe risk is
anticipated as this activity spreads eastward. Clusters/line
segments will likely persist east of the Appalachians into VA
through early tonight, though the severe threat will diminish with
eastward extent and after 03z.
...SD to IA this afternoon/evening...
Low-level moisture will be limited, but surface heating beneath
cooling midlevel temperatures will support weak surface-based
buoyancy and the potential for low-topped showers and a few
thunderstorms from SD into IA (in advance of a digging shortwave
trough now over western ND/eastern MT). Relatively cold temperature
profiles will favor some threat for small hail, while steep
low-level lapse rates and 30+ kt flow through the mixed layer favor
gusty outflow winds of 40-50 mph.
..Mosier/Weinman.. 04/14/2025
SPC 1730Z Day 2 Outlook
 Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1204 PM CDT Mon Apr 14 2025
Valid 151200Z - 161200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected on Tuesday or Tuesday night.
...Northeast...
A post-frontal regime will be in place across the Northeast Tuesday.
Flow aloft will remain modest with mid-level cooling through the
day. This will support potential for redevelopment of scattered
thunderstorm activity by the afternoon. Given post-frontal drying
conditions and weak buoyancy, this should yield primarily sub-severe
low-topped convection, though occasional gusty winds will be
possible.
...Southwest...
A mid-level low will approach the West Coast, with a belt of
mid-level flow overspreading southern California into southern
Nevada. Ahead of this feature, a weak shortwave trough will move
across the Lower Colorado Valley towards the southern Rockies.
Enough mid-level moisture in place with large-scale ascent will
allow for isolated to scattered thunderstorm activity across the
northern Sierra and across the Four Corners region. As shear
profiles will be weak, storms are not expected to be severe.
..Thornton/Leitman.. 04/14/2025
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