RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sat Jun 20 18:31:02 UTC 2026.
MD 1210 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR THE BIG BEND REGION OF FLORIDA INTO FAR SOUTHERN GEORGIA
Mesoscale Discussion 1210
NWS Storm Prediction Center Norman OK
1242 PM CDT Sat Jun 20 2026
Areas affected...The Big Bend region of Florida into far southern
Georgia
Concerning...Severe potential...Watch unlikely
Valid 201742Z - 201945Z
Probability of Watch Issuance...5 percent
SUMMARY...A localized corridor of higher wind potential may be
emerging across the Big Bend region of Florida and into adjacent
portions of far southern Georgia. Watch issuance is not expected.
DISCUSSION...Recent GOES IR imagery shows steady deepening of
incipient convection to the west of Tallahassee, FL that has
developed within a weak low-level confluence zone. This activity may
be influenced by a weak MCV noted in visible imagery and regional
VWP observations across extreme southwest GA. Over the past hour,
the KTLH VWP has shown a slight increase in 6 km winds that is
supporting some hodograph elongation as the MCV passes to the north.
Consequently, it appears plausible that a loosely organized
convective band may emerge over the next 1-2 hours across the Big
Bend region as convection continues to intensify. Further warming of
the downstream environment will likely yield low-level lapse rates
on the order of 7-8 C/km that should support some potential for
damaging wind gusts over the next few hours. Despite this potential,
the modest kinematic environment and a pocket of drier, less buoyant
air far downstream across northern FL will likely limit the overall
intensity, duration, and spatial extent of this threat and negate
the need for watch issuance.
..Moore/Hart.. 06/20/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...JAX...TAE...
LAT...LON 29738470 30078479 30278494 30428500 30578495 30648476
30768283 30698258 30558243 30318246 29988258 29718287
29658298 29608338 29878365 29998385 30068406 30038422
29898439 29738470
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MD 1209 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN FLORIDA PENINSULA
Mesoscale Discussion 1209
NWS Storm Prediction Center Norman OK
1206 PM CDT Sat Jun 20 2026
Areas affected...Eastern Florida Peninsula
Concerning...Severe potential...Watch unlikely
Valid 201706Z - 201930Z
Probability of Watch Issuance...5 percent
SUMMARY...Sporadic damaging wind gusts associated with wet
downbursts will be possible through late afternoon. This threat will
remain sufficiently isolated and transient to negate the need for a
watch.
DISCUSSION...Thunderstorm initiation has been well underway over the
past hour per regional radar and GOES imagery. Minimal capping
within a very moist environment, combined with weak ascent along a
subtle confluence axis, has resulted in convective initiation
slightly earlier than anticipated by most 12z solutions. Despite
around 2000 J/kg MLCAPE, negligible deep-layer wind shear will
promote mainly pulse convection and multi-cell clusters with several
outflow boundaries from this initial activity already apparent in
radar imagery. With surface temperatures still relatively early in
the diurnal heating cycle, low-level thermodynamic conditions
(primarily low-level lapse rates) are currently not optimal to
support a more robust downburst threat. However, continued heating
through the afternoon should yield pockets of higher MLCAPE and
steeper low-level lapse rates that should favor a greater potential
for strong to severe downbursts as convection spreads
east/southeast. Based on latest radar/satellite trends, this appears
most likely along the east-central to southeastern FL Peninsula.
Regardless, the overall severe wind risk will likely remain fairly
isolated and transient.
..Moore/Hart.. 06/20/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MFL...MLB...TBW...
LAT...LON 25408019 25448049 25678077 26148116 26788136 27768181
28088188 28538174 28778154 28858108 28858073 28438045
28178045 27848037 27408018 27098007 26837999 26638000
25718007 25408019
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1109 AM CDT Sat Jun 20 2026
Valid 201630Z - 211200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS THIS AFTERNOON AND TONIGHT....
...SUMMARY...
Severe thunderstorms are likely across parts of the central Plains
mainly this afternoon and evening. Large to very large hail, severe
winds (some 75+ mph), and a few tornadoes are possible.
...Central Plains...
Water vapor imagery shows a shortwave trough over ID/UT tracking
eastward toward the central High Plains. Southerly/southeasterly
low-level winds ahead of this feature over parts of eastern
CO/western NE/KS will help to maintain a moist and moderately
unstable air mass across the region, especially as low clouds
continue to burn off and afternoon heating commences. Scattered
thunderstorm development is expected by mid-afternoon over central
WY down into central CO in favored terrain/convergence areas. This
activity will spread eastward into a progressively more
moist/unstable air mass and intensify into supercells. A corridor
of favorable vertical shear will develop later today from northeast
CO into southwest NE/northwest KS for isolated tornadoes.
Otherwise, very large hail and damaging winds will be the main
concerns. Activity is likely to organize upscale during the evening
and spread across KS with a damaging wind risk persisting much of
the night.
...Southeast...
A very moist and moderately unstable air mass is present again today
over much of the southeast US. Most CAM solutions suggest scattered
afternoon thunderstorms across this area, including along the FL
east coast. Dewpoints in the 70s and PWAT values around 2 inches,
coupled with strong daytime heating and steep low-level lapse rates
suggest a risk of locally gusty/damaging wind gusts in the most
intense cores.
..Hart/Moore.. 06/20/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1223 PM CDT Sat Jun 20 2026
Valid 211200Z - 221200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
HIGH PLAINS INTO THE OHIO VALLEY...
...SUMMARY...
Severe storms are possible along a frontal zone from the Ohio Valley
to the central High Plains from Sunday afternoon into night. Large
to very large hail, severe winds, and tornadoes (some of which could
be strong) will be possible.
...Synopsis...
A series of vorticity maxima, some with convective origins, will
translate east through the central Plains and OH Valley, along with
a belt of 40-50+ kt winds at 500 mb. In the lower levels, a
southwesterly low-level jet (LLJ) initially from the southern Plains
into the mid MO Valley Sunday morning is forecast to migrate east
into the mid MS and OH Valleys, immediately ahead of a surface low
tracking through the lower MO Valley into IL/IN. A cold front will
trail the surface low, likely extending southwest through the lower
MO Valley into southern KS or northern OK and the TX Panhandle by
mid to late afternoon.
...Missouri into the OH Valley...
Latest models remain consistent with previous runs in depicting one
or multiple MCSs ongoing at 12Z Sunday along the LLJ axis from
eastern KS into parts of northern and central MO. While the models
signal a general decrease in storm coverage through the morning, the
presence of modestly strong vertical shear suggests the potential
for isolated occurrences of damaging winds and perhaps some hail
across MO into western IL.
Renewed storm development is anticipated by afternoon from IL/IN in
the vicinity of a remnant MCV west/southwest along the trailing
outflow/warm frontal boundary to the primary surface low over the
lower MO Valley. Enhanced warm thermal and moisture fluxes occurring
along the LLJ are expected to support air mass recovery in the wake
of the early-day storms with moderate to potentially strong
instability forecast from the lower OH Valley into the Ozarks, south
of the composite boundary.
Forecast soundings and plan-view kinematic fields indicate
relatively strong low-level and deep-layer shear in the vicinity of
the composite boundary across portions of MO/IL/IN Sunday afternoon
into evening, where the highest probability of supercells and/or
bowing structures capable of all hazards (including strong
tornadoes) is expected to exist. However, as was alluded to in the
initial Day 2 discussion, and is still the case, there is
considerable latitudinal variability in the composite boundary
location. As such, uncertainty remains too high to delineate higher
severe-weather probabilities for this region.
...Central High Plains...
A trailing vorticity lobe and western extension of a 40-50 kt
mid-level jet maximum are expected to support weak cyclogenesis
along a front or trough pushing into the region from the west. Ahead
of that boundary, steep low/mid-level lapse rates and modest
boundary-layer moisture content are expected to yield moderate
afternoon instability amidst sufficiently strong deep-layer shear to
support supercell storm modes capable of large to very large hail.
Most recent model guidance has shifted the corridor of preferred
storm development and residence slightly east across portions of
western and central NE into northwest KS, and the severe-weather
probabilities have been adjusted accordingly. Storms may congeal
into clusters Sunday evening with the severe-weather threat
transitioning more to damaging winds.
...Southern Kansas and northern Oklahoma into the Ozark Plateau...
High-resolution model guidance suggests that a sub-synoptic-scale
surface low/frontal wave may evolve Sunday afternoon along the
trailing front. Enhanced convergence near and east of that feature
should be sufficient to overcome the cap and allow for isolated to
widely scattered storm development. The combination of moderate to
strong instability and around 40 kt of deep-layer shear will support
supercells as the initial storm mode with a risk for large to very
large hail. A largely parallel orientation of the deep shear vector
to the surface front suggests the potential for merging storms
within a few hours after initiation, with damaging wind potential
increasing at that time. Storms are expected to grow upscale into
one or multiple MCSs with at least an isolated damaging-wind threat
spreading south through the Ozark Plateau region Sunday night.
..Mead.. 06/20/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
1105 AM CDT Sat Jun 20 2026
Valid 231200Z - 281200Z
CORRECTED FOR TYPO
...DISCUSSION...
An extended period of moderate northwesterly flow across the High
Plains will lead to severe weather potential across the central High
Plains. Upslope flow amid 30 to 50 knots mid-level winds should
result in a severe weather environment, potentially on Tuesday, and
particularly Wednesday and Thursday. The front will shift based on
small-scale embedded shortwave disturbances and the prior day's
convection, which will shift the location of the unstable warm
sector. This results in uncertainty regarding the location of the
threat for each day. This will continue to be monitored for
potential areas to be added later.
Ridging will slide east across the Rockies and into the Plains by
next weekend. Some severe weather threat may exist through this time
as multiple embedded shortwave troughs will be within this region as
instability increases across the Plains.
While it is mostly beyond Day 8, it is worth noting that
deterministic, ensemble, and AI guidance all indicate a strong jet
streak and mid-level trough traversing the Rockies toward the end of
next weekend and into early next week. A strong lee cyclone would
accompany this with strong instability across the Plains. There is
still uncertainty with the timing and location of the trough, but
given the agreement in this general pattern change, a substantial
severe weather threat seems possible by the end of next weekend and
early into the following week across portions of the
central/northern Plains into the Upper Midwest.
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1048 AM CDT Sat Jun 20 2026
Valid 201700Z - 211200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHEASTERN GREAT
BASIN FOR SCATTERED DRY THUNDERSTORMS...
...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE EASTERN GREAT BASIN
INTO THE FOUR CORNERS FOR DRY AND WINDY CONDITIONS...
The existing Isolated Dry Thunderstorm area was trimmed slightly
along it's northern boundary to account for ongoing showers with
accumulating precipitation and persistent cloud cover this morning.
This activity, over east-central OR and far western ID, will stifle
chances for dry thunderstorm re-development later today as indicated
in the latest forecast guidance and will also limit fuel
receptivity. Across portions of this same area, this accumulating
precipitation may also prevent afternoon RHs from dipping low enough
to meet Elevated wind/RH criteria. However, the latest forecast
guidance still maintains Elevated criteria (with RHs dipping below
20%) will be met this afternoon over much of the drawn area. Farther
south over the rest of the Great Basin, Southwest, and neighboring
areas, the forecast remains on track. Northern portions of the
Scattered Dry Thunderstorm area did receive transitory precipitation
this morning, but it is not expected to have a significant impact
unlike the longer duration showers over areas farther northwest.
..Stearns.. 06/20/2026
.PREV DISCUSSION... /ISSUED 0147 AM CDT Sat Jun 20 2026/
...Synopsis...
Zonal mid-level flow will overspread the CONUS today, with multiple
embedded impulses poised to traverse the zonal flow from the Pacific
Northwest to the mid-Mississippi Valley. At least one pronounced
mid-level impulse will overspread the Great Basin during the
afternoon hours, encouraging surface troughing over the Interior
West, resulting in dry/windy conditions over the Great Basin toward
the Four Corners region. Strong westerly mid-level flow behind the
mid-level impulse will overspread the Cascades, supporting
dry/breezy conditions over and to the lee of the higher terrain.
Finally, deep-layer ascent and enough mid-level moisture (hence
buoyancy) accompanying the passing mid-level impulse will encourage
high-based thunderstorm development from northern California to
western Wyoming. The combination of these meteorological scenarios
will support widespread wildfire ignition and/or growth concerns
across much of the Intermountain West today.
...Eastern Great Basin to the Four Corners region...
By afternoon peak heating, the aforementioned surface lee troughing
will support widespread southwesterly surface winds in the 15-25 mph
range amid 5-15 percent RH. Widespread Elevated highlights have been
continued, with Critical highlights in place where guidance shows
the highest likelihood of 20+ mph winds and 5-10 percent RH
overlapping for several hours. Across both Elevated and Critical
highlights, ERCs should easily exceed the 80th percentile, and thus
would support wildfire spread.
...Along and to the lee of the Cascades...
Strong flow westerly flow along the higher terrain, along with
downslope flow to the lee of the Cascades, will result in 15-25 mph
sustained westerly surface winds coinciding with RH as low as 15
percent in spots. Stronger surface winds and lower RH may occur in
localized, terrain favoring areas. Either way, the aforementioned
ambient surface conditions and dry fuels warrant Elevated
highlights.
...Far northern California to far western Wyoming...
During the afternoon, diurnal heating, upper support, and orographic
lift will all support at least isolated thunderstorm development
amid precipitable water values around 0.75 inches. Given dry fuels
and potentially light rainfall accumulations with some of the storm
cores, a few cells may be associated with efficient
lightning-induced ignitions given cloud-to-ground strikes,
warranting isolated dry thunderstorm highlights. Across northeastern
portions of the Great Basin, storms closer to stronger mid-level
flow may move faster, potentially supporting a regionally greater
lightning-ignition rate given dry fuels and a lesser chance for
rainfall accumulations. As such, scattered dry thunderstorm
highlights have been continued.
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0129 PM CDT Sat Jun 20 2026
Valid 211200Z - 221200Z
Minor adjustments were made to the Elevated areas on Day 2/Sunday.
The latest forecast guidance shows that elevated wind/RH
combinations over portions of the Southwest will expand slightly
eastward into the eastern NM plains. The current eastern extent is
limited by fuels receptivity as both live and dead fuels remain
below critical dryness thresholds across this region. Farther north,
across the Snake River Plain of ID, the areal extent of the
anticipated Elevated conditions there was trimmed slightly in
agreement with the latest forecast guidance keeping the driest
afternoon RHs constrained to the lowest elevations.
..Stearns.. 06/20/2026
.PREV DISCUSSION... /ISSUED 0154 AM CDT Sat Jun 20 2026/
...Synopsis...
Zonal mid-level flow will persist over the CONUS, with embedded
impulses continuing to traverse this flow tomorrow (Sunday). Surface
low development over the southern High Plains will encourage dry
westerly surface flow over portions of the Desert Southwest. By
afternoon, 15+ mph sustained westerly surface winds and 5-10 percent
RH atop dry fuels will promote conditions favorable for wildfire
spread, hence the introduction of Elevated highlights. Channeled
flow within the Snake River Plain will also support Elevated
dry/windy conditions by afternoon. Here, sustained westerly surface
winds are expected to exceed 15 mph for at least a few hours as RH
dips below 15 percent.
...Please see www.spc.noaa.gov/fire for graphic product...
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