949
ACUS02 KWNS 050445
SWODY2
SPC AC 050443
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1143 PM CDT SAT JUL 04 2026
VALID 061200Z - 071200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY INTO
MONDAY EVENING ACROSS PARTS OF THE CENTRAL AND EASTERN DAKOTAS
THROUGH NORTHERN MINNESOTA AND ACROSS PARTS OF THE MID ATLANTIC...
..SUMMARY
STRONG THUNDERSTORM DEVELOPMENT POSING AT LEAST SOME RISK FOR SEVERE
WEATHER IS POSSIBLE ACROSS PARTS OF NORTHERN MINNESOTA THROUGH THE
EASTERN AND CENTRAL DAKOTAS, AS WELL AS ACROSS PARTS OF THE MID
ATLANTIC, MONDAY AFTERNOON INTO EVENING.
..DISCUSSION
DOWNSTREAM OF DIGGING LARGE-SCALE MID-LEVEL TROUGHING AND AN
ASSOCIATED SURFACE CYCLONE SLOWLY APPROACHING THE BRITISH COLUMBIA
AND PACIFIC NORTHWEST COAST, RIDGING MAY BECOME INCREASINGLY
PROMINENT ACROSS BAJA CALIFORNIA THROUGH THE SOUTHERN ROCKIES AND
CENTRAL GREAT PLAINS DURING THIS PERIOD. MID-LEVEL HEIGHTS MAY TEND
TO REMAIN STEADY OR SLOWLY RISE AS FAR NORTH AS THE EASTERN
MONTANA/NORTH DAKOTA INTERNATIONAL BORDER, IN THE WAKE OF A NOTABLE
MID-LEVEL TROUGH FORECAST TO PROGRESS THROUGH NORTHWESTERN ONTARIO
AND HUDSON BAY BY LATE MONDAY NIGHT.
IT APPEARS THAT ONE VIGOROUS IMPULSE EMBEDDED WITHIN THE TROUGHING,
AND FORECAST TO CONTINUE ACCELERATING EAST-NORTHEASTWARD, TO THE
NORTH OF THE INTERNATIONAL BORDER, MAY PROVIDE SUPPORT FOR STRONGER
SECONDARY SURFACE CYCLOGENESIS ACROSS THE SOUTHERN HUDSON BAY
VICINITY BY MONDAY NIGHT.
TO THE EAST OF THE MID-LEVEL RIDGING, WEAK MID-LEVEL TROUGHING MAY
CONTINUE TO DRIFT SLOWLY EAST OF THE MISSISSIPPI VALLEY, TOWARD THE
APPALACHIANS.
IN ASSOCIATION WITH THIS EVOLVING REGIME, THE POTENTIAL FOR
ORGANIZED SEVERE THUNDERSTORM ACTIVITY STILL APPEARS GENERALLY LOW
AND DEPENDENT ON SUB-SYNOPTIC DEVELOPMENTS WITH RATHER LOW
PREDICTABILITY AT THIS TIME FRAME. THIS CONTINUES TO BE REFLECTED
IN LATEST MODEL OUTPUT, INCLUDING CONVECTION ALLOWING AND RELATED
GUIDANCE, WHICH EXHIBIT SIZABLE SPREAD CONCERNING POTENTIAL
CONVECTIVE EVOLUTION AND LOCATIONS WITH HIGHER PROBABILITIES FOR
THUNDERSTORM DEVELOPMENT.
..NORTHERN GREAT PLAINS
DEEPER SURFACE TROUGHING AND MID-LEVEL HEIGHT FALLS ARE FORECAST TO
PASS TO THE NORTH OF THE INTERNATIONAL BORDER THROUGH THIS PERIOD.
HOWEVER, THERE APPEARS AT LEAST SOME CONTINUING SIGNAL IN MODEL
OUTPUT THAT BOUNDARY-LAYER MOISTURE RETURN TO THE VICINITY OF WEAK
PRE-FRONTAL SURFACE TROUGHING, COINCIDENT WITH SOUTHEASTWARD
SUPPRESSION OF WARMER AND MORE STRONGLY CAPPING ELEVATED MIXED-LAYER
AIR, COULD ALLOW FOR SCATTERED STRONG THUNDERSTORM DEVELOPMENT BY
LATE MONDAY AFTERNOON. IF THIS OCCURS, MODERATE TO LARGE POTENTIAL
INSTABILITY, IN THE PRESENCE OF AT LEAST MODEST SHEAR BENEATH 30-40
KT 500 MB FLOW, PROBABLY WILL BE CONDUCIVE TO STORMS CAPABLE OF
PRODUCING SEVERE HAIL AND WIND, BEFORE PERHAPS TENDING TO BE
UNDERCUT BY A SOUTHWARD ADVANCING COLD FRONT TRAILING THE DEVELOPING
CANADIAN CYCLONE.
..MID ATLANTIC
THE TIMING AND/OR LOCATION OF HIGHEST THUNDERSTORM PROBABILITIES
ACROSS THE REGION DIFFERS NOTABLY BETWEEN THE REFS AND HREF
CALIBRATED THUNDERSTORM GUIDANCE, AND DEEP-LAYER MEAN FLOW AND SHEAR
WILL BE RATHER WEAK. HOWEVER, DESTABILIZATION WITHIN BROAD, WEAK
SURFACE TROUGHING TO THE LEE OF THE BLUE RIDGE MIGHT BECOME
SUFFICIENT TO FOCUS SCATTERED THUNDERSTORM DEVELOPMENT WITH
POTENTIAL TO PRODUCE LOCALIZED DAMAGING SURFACE GUSTS MONDAY
AFTERNOON INTO EARLY EVENING.
..KERR.. 07/05/2026
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