RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sat Jun 20 11:01:02 UTC 2026.
No Mesoscale Discussions are in effect as of Sat Jun 20 11:01:02 UTC 2026.
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0238 AM CDT Sat Jun 20 2026
Valid 221200Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
HIGH PLAINS AND SOUTHERN PLAINS TO THE MID-SOUTH AND INTO THE
CAROLINAS AND MID-ATLANTIC....
CORRECTED FOR CAPITALIZATION IN THE SUMMARY
...SUMMARY...
Isolated strong to severe storms are expected along a frontal zone
that extends from the mid-Atlantic to the Mid-South and southern
Plains and into the central High Plains on Monday.
...Synopsis...
A flat ridge is forecast across the western CONUS with broad
cyclonic flow from the southern Plains to the Mid-Atlantic. Within
this zone, several embedded mid-level shortwave troughs are
expected, the strongest of which will move from the Ohio Valley to
the Mid-Atlantic during the day Monday. A weak surface low will
likely be associated with this lead shortwave trough with an
additional lee trough, likely across the southern High Plains. A
frontal zone will extend between these 2 features and act as the
primary focus for storm development through the period on Monday.
...Central/southern Plains...
A MCS should be ongoing at the beginning of the period across parts
of Oklahoma on the nose of the low-level jet. An outflow boundary
will likely extend westward from this MCS into parts of Northwest
Texas and into the Texas Panhandle.
Very strong to extreme instability is forecast across the southern
Plains on Monday with dewpoints in the mid to upper 70s and steep
lapse rates. Model guidance is consistent showing a weak mid-level
shortwave trough emerging across the southern Plains by 00Z Tuesday
with 30 to 35 knots of mid-level flow. The combination of this
shortwave trough and the potential for an outflow boundary
intersecting the dryline may result in a more focused area of severe
potential Monday afternoon/evening. However, due to the mesoscale
nature of this potential, confidence is not high enough to add a
Slight Risk at this time.
...Mid South...
Moderate to strong instability is forecast to develop ahead of the
MCS across Oklahoma and Arkansas Monday morning. Given the very
moist airmass, inhibition should be eroded by mid-day. Therefore,
reintensification of the morning MCS or additional development to
the east along the front (likely a combination of both) is expected
from near the Red River to northern Mississippi. This strong
instability, combined with modest shear, will support some damaging
wind threat with a southeastward moving cluster of storms Monday
afternoon/evening.
...Carolinas to the Mid-Atlantic...
A moist airmass will move into the Carolinas and Mid-Atlantic on
Monday ahead of an eastward moving cold front. Mid-level lapse rates
will be weak which will limit overall instability, but moderate
shear and sufficient instability, combined with steep low-level
lapse rates will support some damaging wind threat Monday
afternoon/evening. In addition, a smaller area of greater low-level
shear may exist closer to the surface low across northern Virginia
and vicinity, which could have a localized region of greater tornado
threat.
..Bentley.. 06/20/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0330 AM CDT Sat Jun 20 2026
Valid 231200Z - 281200Z
...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 nothing 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
0147 AM CDT Sat Jun 20 2026
Valid 201200Z - 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...
...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.
..Squitieri.. 06/20/2026
...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
0154 AM CDT Sat Jun 20 2026
Valid 211200Z - 221200Z
...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.
..Squitieri.. 06/20/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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