960
ACUS01 KWNS 072001
SWODY1
SPC AC 072000
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT SUN JUN 07 2026
VALID 072000Z - 081200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
SOUTHEASTERN MONTANA...EXTREME NORTHWESTERN SOUTH DAKOTA...WESTERN
AND CENTRAL NORTH DAKOTA,...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF
SOUTHWESTERN MISSOURI AND FAR NORTHWESTERN ARKANSAS...
..SUMMARY
A BOW ECHO WITH 60-100 MPH GUSTS APPEARS LIKELY OVER THE NORTHERN
HIGH PLAINS INTO THE DAKOTAS THIS AFTERNOON, WITH A FEW INSTANCES OF
SEVERE HAIL AND ISOLATED TORNADOES ALSO POSSIBLE. A COUPLE OF
TORNADOES AND ISOLATED DAMAGING GUSTS ARE STILL POSSIBLE ACROSS THE
OZARKS REGION.
..20Z UPDATE
A CATEGORY 4/MODERATE RISK WAS INTRODUCED TO PORTIONS OF THE
NORTHERN HIGH PLAINS. CONFIDENCE IS INCREASING IN A WELL-DEFINED
COLD-POOL-DRIVEN BOW ECHO MCS DEVELOPING ACROSS PORTIONS OF THE
NORTHERN HIGH PLAINS LATER THIS AFTERNOON. A POTENTIALLY DENSE SWATH
OF 60-100 MPH GUSTS APPEARS LIKELY, AND A DERECHO MAY OCCUR. CURRENT
OBSERVATIONS DEPICT A NEAR STATIONARY SURFACE BOUNDARY ACROSS FAR
SOUTHEASTERN MT NORTHEASTWARD INTO WESTERN ND ALONG AN ELONGATED
SURFACE TROUGH. HIGH-RESOLUTION DETERMINISTIC AND ENSEMBLE GUIDANCE
(INCLUDING HREF, REFS, AND SOME OF THE LATEST WOFS RUNS) ALL DEPICT
A CLASSIC BOW ECHO MCS TRAVERSING THIS SURFACE BOUNDARY, ACCOMPANIED
BY A WIDESPREAD SEVERE WIND SWATH AND SCATTERED 75+ MPH GUSTS. THE
MCS WOULD BENEFIT FROM LOCALIZED VORTICITY ALONG THIS BOUNDARY,
WHICH IN TURN COULD SUPPORT BOOK-END VORTICES AND THE SUBSEQUENT
DEVELOPMENT AND SUSTENANCE OF A REAR-INFLOW JET, LENDING
PLAUSIBILITY TO THE GUIDANCE CONSENSUS. LATEST MESOANALYSIS ALSO
SHOWS CONTINUED ERODING MLCINH AND 2500+ J/KG MLCAPE IN PLACE. LOW-
TO MID-LEVEL LAPSE RATES ARE ALREADY EXCEEDING 8 C/KM IN SOME SPOTS,
COINCIDING WITH 50-60 KTS OF SFC-8 KM BULK SHEAR ORIENTED NORMAL TO
THE ANTICIPATED BOW ECHO LEADING LINE, WHICH IS FAVORABLE FOR
DERECHO DEVELOPMENT. ALTERNATIVELY, MULTIPLE SEVERE-WIND PRODUCING
MULTICELLULAR CLUSTERS MAY OCCUR, WHICH WOULD SUPPORT HIGHER
COVERAGE OF SEVERE WINDS (WITH GUSTS OCCASIONALLY EXCEEDING 75 MPH).
OTHERWISE, THE PREVIOUS FORECAST REMAINS ON TRACK, WITH ONLY MINOR
CHANGES MADE TO THUNDER AND SEVERE PROBABILITIES TO REFLECT THE
LATEST OBSERVATIONS.
..SQUITIERI.. 06/07/2026
PREV DISCUSSION
/ISSUED 1139 AM CDT SUN JUN 07 2026/
..MT/WY/DAKOTAS
WATER-VAPOR IMAGERY LATE THIS MORNING SHOWS A STRONG UPPER TROUGH
OVER THE NORTHWESTERN CONUS AND IT IS FORECAST TO PIVOT EASTWARD
THROUGH THE NORTHERN HIGH PLAINS THROUGH TONIGHT. SURFACE
MESOANALYSIS PLACED A LOW NEAR THE MT/ND/SD BORDER WITH A FRONTAL
ZONE DRAPED SOUTHWEST TO NORTHEAST FROM NORTHEASTERN WY INTO FAR
WESTERN ND. CYCLOGENESIS AND STRONG HEATING/MOISTENING OF THE
BOUNDARY LAYER WILL FAVOR STORM DEVELOPMENT BY MID AFTERNOON IN THE
VICINITY OF THE BIG HORNS. RELATIVELY STEEP LOW-LEVEL LAPSE RATES
ON THE IMMEDIATE COOL SIDE OF THE FRONTAL ZONE AND MODERATE CAPE
VALUES WILL SUPPORT A RISK OF LARGE HAIL AND SEVERE WIND GUSTS ONCE
STORMS BEGIN TO MATURE. A LINEAR CLUSTER IS EXPECTED TO EVOLVE
DURING THE LATE AFTERNOON INTO POTENTIALLY A BOW ECHO DURING THE
EARLY EVENING WITH THE SEVERE-WIND RISK NOTABLY INCREASING AND
BECOMING MORE WIDESPREAD. HAVE INCREASED THE INTENSITY HIGHLIGHT
FROM SOUTHEAST MT INTO WESTERN PORTIONS OF ND WHERE IT SEEMS
INCREASINGLY PROBABLE A SWATH OF INTENSE GUSTS ---POSSIBLY A BOW
ECHO--- IS PROGGED BY A DIVERSE ARRAY OF DIFFERENT MODEL CORES/RUNS
THIS MORNING. THIS MODEL SIGNAL APPEARS REASONABLE GIVEN THE
CO-LOCATION OF SURFACE FEATURES, LAPSE RATES, AND UPPER-LEVEL
SUPPORT. IT IS WITHIN THIS MESOSCALE CORRIDOR THAT LOCALIZED PEAK
GUSTS MAY RANGE 85-100 MPH. CONSIDERED AN UPGRADE TO MODERATE RISK
BUT WILL DEFER TO THE 20 UTC OUTLOOK FOR ADDITIONAL MODEL RUN-TO-RUN
CONTINUITY AND CONFIDENCE IN MESOSCALE ENVIRONMENTAL FEATURES. THIS
ACTIVITY WILL SWEEP NORTHEASTWARD DURING THE EVENING WITH A GRADUAL
LESSENING OF THE WIND/HAIL HAZARD TOWARDS THE EARLY OVERNIGHT AS IT
MOVES EAST INTO THE EASTERN HALF OF THE DAKOTAS LATE.
..OZARKS
A WEAK TROUGH/LOW OVER THE CENTRAL US WITH EMBEDDED DISTURBANCES
FROM OK INTO IA CONTINUES TO DRIFT NORTHEASTWARD LATE THIS
MORNING. AN ASSOCIATED BAND OF 30-40 KNOT SOUTHWESTERLY MID-LEVEL
WINDS AND DEEP MOISTURE WILL LIE ACROSS THE OZARK PLATEAU THIS
AFTERNOON. THE 12 UTC SPRINGFIELD, MO RAOB SAMPLED THIS BELT OF
STRONGER FLOW WITH 80-KT AT 200 MB. HEATING OF A VERY MOIST AIRMASS
WITH SOME MINOR ENLARGEMENT OF LOW-LEVEL HODOGRAPHS MAY RESULT A FEW
WEAK SUPERCELLS DEVELOPING COINCIDENT WITH PEAK HEATING. A COUPLE
OF BRIEF TORNADOES AND ISOLATED DAMAGING GUSTS ARE POSSIBLE WITH
THIS ACTIVITY.
..EASTERN VA/NC
A WEAK SURFACE COLD FRONT IS SAGGING SOUTHWARD ACROSS CENTRAL VA
THIS MORNING. A COMBINATION OF STRONG HEATING AND FRONTAL FORCING
WILL LEAD TO WIDELY SCATTERED THUNDERSTORMS THIS AFTERNOON ACROSS
SOUTHEAST VA AND NORTHEAST NC. THE STRONGEST OF THESE CELLS COULD
PRODUCE GUSTY WINDS.
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