134
ACUS02 KWNS 221732
SWODY2
SPC AC 221730
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT SAT AUG 22 2026
VALID 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
CENTRAL AND EASTERN MONTANA AND PARTS OF THE EASTERN GREAT BASIN
INTO THE CENTRAL ROCKIES...
..SUMMARY
STRONG THUNDERSTORM ACTIVITY POSING AT LEAST SOME RISK FOR SEVERE
HAIL AND WIND APPEARS POSSIBLE ACROSS PARTS OF THE NORTHERN ROCKIES
AND GREAT PLAINS, AND ACROSS PARTS OF THE EASTERN GREAT LAKES TO THE
NORTHEAST, SUNDAY THROUGH SUNDAY NIGHT.
..SYNOPSIS
UPPER RIDGING WILL PREVAIL ACROSS THE WESTERN CONUS AS AN UPPER
TROUGH SLOWLY TRAVERSES THE NORTHEAST TOMORROW (SUNDAY). A MID-LEVEL
IMPULSE WILL CREST THE UPPER RIDGE TOMORROW AFTERNOON ACROSS THE
NORTHERN ROCKIES WHILE A SMALL IMPULSE EMBEDDED IN THE
AFOREMENTIONED UPPER TROUGH OVERSPREADS THE NORTHERN APPALACHIANS.
FROM THE NORTHERN ROCKIES TO NORTHERN HIGH PLAINS, AS WELL AS PARTS
OF THE NORTHEAST, STRONGER FLOW ABOVE THE BOUNDARY LAYER WILL
PROMOTE ADEQUATE VERTICAL WIND SHEAR, IN TANDEM WITH BUOYANCY, TO
PROMOTE STRONG TO SEVERE THUNDERSTORMS. ELSEWHERE FROM THE CENTRAL
ROCKIES TO THE GULF/CAROLINA COASTLINES, STRONG SURFACE HEATING AMID
POCKETS OF LOW-LEVEL MOISTURE WILL SUPPORT SCATTERED THUNDERSTORM
DEVELOPMENT, WITH AN ISOLATED SEVERE STORM POSSIBLE.
..NORTHERN ROCKIES
BY MID TO LATE AFTERNOON, A WELL-MIXED BOUNDARY LAYER SHOULD DEVELOP
BENEATH A PLUME OF COOLER TEMPERATURES ALOFT (E.G. 8+ C/KM MID-LEVEL
LAPSE RATES) WITH THE PASSAGE OF THE AFOREMENTIONED MID-LEVEL
IMPULSE. A BELT OF STRONGER MID- TO -UPPER LEVEL WESTERLY FLOW WILL
ALSO ACCOMPANY THIS IMPULSE, RESULTING IN ELONGATED HODOGRAPHS AND
30-40 KTS OF EFFECTIVE BULK (SPEED) SHEAR COINCIDING WITH THE STEEP
LOW- AND MID-LEVEL LAPSE RATES. MULTICELLS AND TRANSIENT SUPERCELLS
SHOULD DEVELOP, ACCOMPANIED BY A RISK OF SEVERE GUSTS AND PERHAPS AN
INSTANCE OR TWO OF HAIL. A GUST OVER 75 MPH IS POSSIBLE.
..NORTHERN HIGH PLAINS INTO SOUTH DAKOTA
CONVECTIVE EVOLUTION AND MORPHOLOGY REMAINS UNCLEAR IN THIS REGION.
STEEP LAPSE RATES WILL EMANATE FROM THE NORTHERN ROCKIES AND
OVERSPREAD A MOISTENING WARM SECTOR (E.G. MID 60S F DEWPOINTS),
YIELDING 2000+ J/KG MLCAPE. MODESTLY CURVED AND ELONGATED HODOGRAPHS
SUGGEST MULTICELLS AND SUPERCELLS AS THE MAIN STORM MODE, AT LEAST
INITIALLY. SEVERE GUSTS/HAIL WOULD ACCOMPANY THESE STORMS IF THEY
CAN BECOME SUSTAINED. THERE IS ALSO SOME INDICATION BY THE LATEST
CAMS THAT STORMS MAY MERGE INTO A COLD-POOL-DRIVEN MCS, THOUGH
GUIDANCE CONSENSUS IS WEAK ON THIS SCENARIO. NONETHELESS, ANY MCS
DEVELOPMENT THAT DOES OCCUR WOULD SUPPORT SEVERE GUSTS, INCLUDING A
75+ MPH GUST.
..PORTIONS OF THE EASTERN GREAT BASIN TO THE CENTRAL ROCKIES
A CLUSTER OF MULTICELL STORMS SHOULD DEVELOP AROUND THE EASTERN
GREAT BASIN INTO THE CENTRAL ROCKIES BY AFTERNOON PEAK HEATING.
STRONGER FLOW ALOFT WILL GLANCE THE REGION TO THE NORTH, ATOP A
STRONGLY MIXED BOUNDARY LAYER. FORECAST SOUNDINGS SHOW CLASSIC
INVERTED-V PROFILES EXTENDING TO 500 MB, WITH SURFACE-500 MB LAPSE
RATES REACHING AT LEAST 9 C/KM. AS SUCH, SEVERE GUSTS ARE POSSIBLE
WITH THE STRONGER MULTICELLS THAT FORM.
..PORTIONS OF THE NORTHERN APPALACHIANS INTO NEW ENGLAND
BY AFTERNOON, SURFACE TEMPERATURES SHOULD WARM WELL INTO THE 70S F
AS EARLIER SHOWERS AND THUNDERSTORMS MAKE WAY FOR AT LEAST PARTLY
CLEARING SKIES. WHILE NOT OVERLY STEEP, MID-LEVEL LAPSE RATES
EXCEEDING 6.5 C/KM WILL RESULT IN MARGINAL BUOYANCY, AMID STRONGER
FLOW ALOFT (YIELDING ELONGATED HODOGRAPHS). A COUPLE INSTANCES OF
DAMAGING GUSTS/HAIL WILL BE POSSIBLE WITH THE STRONGER MULTICELLS
THAT MANAGE TO SUSTAIN THEMSELVES.
..GULF TO CAROLINA COASTLINES
A HEATED AND MOIST BOUNDARY LAYER SHOULD DEVELOP BY AFTERNOON GIVEN
THE PRESENCE OF MID 70S F SURFACE DEWPOINTS AND TEMPERATURES RISING
WELL INTO THE 80S F. SUCH RICH LOW-LEVEL MOISTURE WILL SUPPORT
2000-4000 J/KG MLCAPE FROM LA TO EXTREME EASTERN NC DESPITE
MID-LEVEL LAPSE RATES ONLY REACHING 6-6.5 C/KM. ACROSS THE GULF
COAST, PULSE-CELLULAR STORMS ARE EXPECTED GIVEN WEAK FLOW ALOFT,
WITH DAMAGING GUSTS ORIGINATED FROM WET DOWNBURSTS THE MAIN THREAT.
ALONG THE CAROLINA COASTLINE, SOUTHWESTERLY MID-LEVEL FLOW WILL BE A
BIT STRONGER GIVEN THE UPPER TROUGH GLANCING BY TO THE NORTH.
MULTICELLS CAPABLE OF ISOLATED SEVERE GUSTS ARE POSSIBLE. LOCALLY
HIGHER SEVERE PROBABILITIES MAY BE NEEDED IN FUTURE DAY 1 OUTLOOKS
IF GREATER STORM COVERAGE BECOMES APPARENT.
..PORTIONS OF SOUTHERN ARIZONA
LOCALLY STRONGER SOUTHEASTERLY MID-LEVEL FLOW WILL PIVOT AROUND THE
UPPER RIDGE AND OVERSPREAD A DEEP AND DRY BOUNDARY LAYER BY LATE
AFTERNOON/EARLY EVENING. MEANWHILE, SURFACE TEMPERATURES AROUND 100
F, AMID 60 F SURFACE DEWPOINTS AND OVERSPREAD BY MODESTLY COOLER
TEMPERATURES ALOFT, WILL YIELD 9+ C/KM TROPOSPHERIC LAPSE RATES AND
OVER 2000 J/KG MLCAPE. GIVEN THE MODEST FLOW ALOFT AND
AFOREMENTIONED BUOYANCY, A FEW ORGANIZED MULTICELLS MAY OCCUR,
ACCOMPANIED BY AN ISOLATED SEVERE GUST THREAT.
..SQUITIERI.. 08/22/2026
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