064
ACUS01 KWNS 290100
SWODY1
SPC AC 290058
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0758 PM CDT FRI AUG 28 2026
VALID 290100Z - 291200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE GREAT
BASIN...TO THE CENTRAL ROCKIES AND NORTHERN PLAINS...
..SUMMARY
ISOLATED STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE NORTHERN
PLAINS, AND FROM PARTS OF THE GREAT BASIN AND DESERT SOUTHWEST INTO
THE ROCKIES.
..GREAT BASIN/ROCKIES
EVENING WATER VAPOR IMAGERY SHOWED AN EXPANSIVE AREA OF HIGH
PRESSURE CENTERED OVER THE FOUR CORNERS WITH BROAD SOUTHWESTERLY
FLOW ALOFT ONGOING OVER MUCH OF THE GREAT BASIN AND ROCKIES. TO THE
WEST OF THE RIDGE, AN UPPER LOW AND BROAD TROUGH WERE MOVING ONSHORE
ACROSS THE PACIFIC NORTHWEST AND CA RESPECTIVELY. AHEAD OF THESE
FEATURES, SEVERAL WEAKER PERTURBATIONS AND A PLUME OF MID-LEVEL
MOISTURE WERE CONTRIBUTING TO WIDELY SCATTERED THUNDERSTORMS OVER
THE GREAT BASIN AND CENTRAL ROCKIES THIS EVENING.
DESPITE LIMITED BUOYANCY OWING TO EXPANSIVE CLOUD COVER, PLENTIFUL
MONSOON MOISTURE SHOULD CONTINUE TO SUPPORT WIDELY SCATTERED
HIGH-BASED THUNDERSTORMS THIS EVENING AND INTO THE OVERNIGHT HOURS.
AT LEAST ISOLATED STRONG TO SEVERE GUSTS ARE POSSIBLE OWING TO DRY
LOW-LEVELS SUITABLE FOR STRONG DOWNDRAFTS WITH THE ESTABLISHED
STORMS/CLUSTERS. THIS APPEARS MOST LIKELY FROM FAR EASTERN NV,
ACROSS NORTHERN UT, AND INTO CENTRAL WY WHERE THE AIR MASS REMAINS
THE WARMEST.
..NORTHERN PLAINS
THE FIRST OF THE MID-LEVEL SHORTWAVE TROUGHS EMBEDDED WITHIN THE
BROADER SOUTHWEST FLOW ARE EXPECTED TO EJECT EASTWARD OVER THE
NORTHERN PLAINS TONIGHT. AS ASCENT FROM THE WAVE OVERSPREADS A WARM
FRONT, THE LOW-LEVEL JET IS FORECAST TO STRENGTHEN (40-50 KT),
SUPPORTING A BROAD AREA OF LOW-LEVEL WARM AIR ADVECTION ACROSS THE
EASTERN DAKOTAS INTO MN/IA. ELEVATED STORMS SHOULD DEVELOP NEAR THE
FRONT WITH MODERATE BUOYANCY AND DEEP-LAYER SHEAR SUPPORTIVE OF
SUPERCELLS. SOME HAIL RISK IS POSSIBLE WITH THESE STORMS OVERNIGHT.
GIVEN THE INCREASING FORCING FOR ASCENT, UPSCALE GROWTH INTO A
CLUSTER OR MCS IS POSSIBLE, WHICH COULD RESULT IN A LOW-PROBABILITY
RISK FOR DAMAGING GUSTS OVER SOUTHWEST MN AND ADJACENT NORTHWEST IA
THROUGH 12Z SATURDAY.
..MID ATLANTIC TO THE SOUTHEAST
SEVERAL CLUSTERS OF SCATTERED THUNDERSTORMS REMAIN ONGOING AHEAD OF
A WEAK FRONT FROM VA TO THE NORTHERN GULF COAST. THESE STORMS HAVE
SLOWLY WEAKENED THROUGH THE EVENING AND SHOULD CONTINUE TO DO SO
WITH THE LOSS OF DIURNAL HEATING. AHEAD OF THE FRONT, HIGH PWAT
CONTENT (2-2.5 INCHES) MAY STILL SUPPORT A SPORADIC DOWNBURSTS WITH
THE STRONGER CLUSTERS THIS EVENING. HOWEVER, WEAK SHEAR AND WANING
DIURNAL BUOYANCY SUGGEST AN ORGANIZED OR EXPANSIVE SEVERE THREAT IS
UNLIKELY.
..LYONS.. 08/29/2026
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page