RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Nov 18 07:12:02 UTC 2025.
MD 2207 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF MO INTO FAR NORTHEAST OK/NORTHWEST AR
Mesoscale Discussion 2207
NWS Storm Prediction Center Norman OK
1155 PM CST Mon Nov 17 2025
Areas affected...Parts of MO into far northeast OK/northwest AR
Concerning...Severe potential...Watch unlikely
Valid 180555Z - 180830Z
Probability of Watch Issuance...5 percent
SUMMARY...Strong to locally severe storms are possible overnight.
Isolated hail is expected to be the primary threat.
DISCUSSION...A compact mid/upper-level low is moving eastward across
NE late this evening. Southeast of this low, a strong (40+ kt)
southwesterly low-level jet is currently being sampled by area VWPs.
The warm-advection regime associated with this low-level jet will
support additional rounds of elevated convection overnight from the
Ozarks into the mid MS Valley.
The most favorable environment for organized storms overnight will
extend from northeast OK/northwest AR into central/southern MO,
where a plume of moderate MUCAPE (1000-2000 J/kg) will overlap
favorable effective shear (greater than 40+ kt). While this
environment would conditionally support elevated supercells, the
strongest large-scale ascent may tend to remain displaced to the
north and east, in closer proximity to the left-exit region of a
jetlet associated with the mid/upper-level low. This results in some
uncertainty regarding the intensity and organization of overnight
elevated convection with southward extent.
Generally modest midlevel lapse rates may temper hail potential to
some extent, but isolated severe hail could accompany the strongest
overnight storms. Locally gusty winds also cannot be ruled out,
especially if any sustained/organized cells or clusters can develop
with time.
..Dean/Hart.. 11/18/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LSX...LZK...SGF...EAX...TSA...
LAT...LON 36799528 37269458 39759300 39669151 38959062 38639030
38009055 37369099 36569204 35839292 35929436 36099471
36799528
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Read more
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1139 PM CST Mon Nov 17 2025
Valid 181200Z - 191200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE LOWER
OHIO VALLEY REGION...
...SUMMARY...
A few strong to severe storms are possible across portions of the
Lower Ohio Valley region.
...Lower OH Valley...
Central Plains upper trough is shifting east toward the mid MS
Valley, in line with latest model guidance. As a 60+kt 500mb speed
max translates across MO into southern IL/IN, this feature will
advance into the lower OH Valley by 19/00z, suppressing the height
field as far south as the OH River. Veered, but strong LLJ will
focus across southern MO-southern IL/IN before being nudged
downstream into eastern KY/southern OH by early evening. Net result
will be for a NW-SE oriented corridor of warm advection to shift
east during the day ahead of a weak surface low near the base of the
short-wave trough.
Earlier thoughts regarding the potential for severe continue as
instability will gradually increase along this corridor as midlevel
temperatures cool and lapse rates steepen a bit. In the absence of
strong boundary-layer heating, the majority of convection that
develops across this region will be elevated and aided in large part
by the LLJ. Forecast soundings suggest lifted parcel level will
gradually lower by late afternoon such that near-surface based
parcels could yield modest instability (800-1000 J/kg). Primary
concern today will be hail with elevated supercells, but some
tornado risk is possible with late-day storms, where parcel lift
reflects lower 60s dew points that are expected to return toward the
confluence of the MS/OH Rivers during the afternoon.
...Lower Colorado River Valley/southwest AZ...
Weak midlevel height falls will spread across the lower CO River
Valley today as the upper low off the southern CA Coast eventually
settles toward the international border/northern Baja Peninsula. As
this features digs southeast, a weak LLJ should extend across
southwestern AZ into the early part of the afternoon. Latest
thinking is scattered convection should evolve ahead of the cold
front as it surges across the lower CO River Valley. Forecast
soundings exhibit ample shear for organized rotating updrafts, but
buoyancy is expected to be weak. Given the modest lapse rates, there
is concern updrafts may struggle a bit and hail is expected to
remain below severe levels. Some consideration was given to adding a
2 percent probability for the risk of a brief tornado but will hold
off at this time given the marginality of the situation.
..Darrow/Moore.. 11/18/2025
Read more
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1213 AM CST Tue Nov 18 2025
Valid 191200Z - 201200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF WEST-CENTRAL TEXAS INTO SOUTH-CENTRAL OKLAHOMA...
...SUMMARY...
Isolated severe storms are possible across parts of the southern
Plains on Wednesday evening into early Thursday.
...Southern Plains...
Southerly low-level flow beneath an upper ridge centered over the
central U.S. will transport Gulf moisture northward across TX and
OK. To the west, an upper low/trough over southern CA and northern
Baja Wednesday morning will develop eastward through the period,
with the system forecast to be over AZ and northwest Mexico by
Thursday morning. Southwesterly deep-layer flow will increase across
the southern Plains as the western upper trough ejects eastward.
However, more substantial height falls are not expected across the
Plains until after 00z, with some guidance maintaining neutral
height tendencies until closer to 06z. Furthermore, warmer midlevel
temperatures around 700 mb may maintain capping for much of the
diurnal period. Forecast soundings across multiple models show quite
a bit of spread with regards to surface-based evolution. While
large-scale ascent will likely remain muted until late in the
period, persistent warm advection and increasing vertical shear may
support isolated to scattered storm development near the stationary
surface boundary from west-central TX toward the Red River during
the evening into the overnight. Modest instability and shear may be
sufficient for isolated strong to severe storms, mainly capable of
producing hail.
...Southeast AZ/southwest NM...
Cooling aloft closer to the upper low/trough will support steep
midlevel lapse rates amid increasing midlevel moisture. This will
result in weak instability amid 40+ kt effective shear magnitudes. A
couple of stronger storms could produce small hail or gusty winds,
but overall severe potential appears limited at this time given a
relatively cool boundary-layer and weak buoyancy.
..Leitman.. 11/18/2025
Read more
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1239 AM CST Tue Nov 18 2025
Valid 181200Z - 191200Z
...NO CRITICAL AREAS...
...Synopsis...
Critical fire weather concerns are not expected for today across the
country, though localized concerns may emerge across portions of the
Southeast and southern Appalachians this afternoon. Early-morning
satellite imagery depicts a weakening upper wave over the central
Plains. This feature, along with an attendant surface low, will
shift eastward into the OH Valley through this evening. Across the
West, another upper wave continues to drift southward along the CA
coast. Strong low-level winds are expected to accompany both of
these systems, however, increasing showers/thunderstorms coincident
with the breezy conditions will mitigate fire weather concerns.
Elsewhere, surface winds are expected to remain sufficiently benign
to limit the fire weather threat.
...Georgia into the Carolinas...
Dry conditions are expected to continue across GA into the Carolinas
for today. Southerly winds will help advect some returning moisture
into the region, but ensemble consensus is that RH minimums in the
20-30% range will be common once again. Surface high pressure will
limit wind speeds to mainly near/below 10 mph based on the 90th
percentile of recent HREF/NBM runs. However, a few locations,
especially at higher elevations, may see occasional gusts upwards of
15-20 mph that may support very localized fire weather concerns.
..Moore.. 11/18/2025
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0110 AM CST Tue Nov 18 2025
Valid 191200Z - 201200Z
...NO CRITICAL AREAS...
...Synopsis...
The potential for critical fire weather conditions appears limited
for Wednesday. Latest guidance shows reasonably strong agreement in
the eastward translation of the southern CA upper low into the Four
Corners region over the next 48 hours. Modest lee
troughing/cyclogenesis is expected as this occurs, but the low-level
wind response is expected to be fairly muted with around 10-15 mph
sustained winds across parts of the southern High Plains.
Additionally, scattered to widespread mid/high-level cloud cover is
anticipated, which will modulate diurnal heating and most likely
limit RH reductions to the 25-35% range. Recent ensemble guidance
hints that some mid-afternoon clearing is possible across far
northeast NM into the OK/TX Panhandles, which may be sufficient for
a pocket of sub-25% RH and winds between 15-20 mph. However, this
potential appears too limited/localized to warrant risk highlights
at this time.
..Moore.. 11/18/2025
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
|
