879
ACUS48 KWNS 100857
SWOD48
SPC AC 100856
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0356 AM CDT WED SEP 10 2025
VALID 131200Z - 181200Z
..DISCUSSION
SEVERE POTENTIAL IN THE EXTENDED FORECAST PERIOD WILL BE TIED TO A
SHORTWAVE TROUGH AND STRONGER SOUTHWESTERLY FLOW ALOFT EMANATING
FROM THE ROCKIES OVER THE CENTRAL US. FLOW ALOFT WILL INCREASE
D4/SATURDAY AS THE UPPER TROUGH BEGINS TO OVERSPREAD THE CENTRAL US.
ASCENT FROM THE TROUGH WILL MAINTAIN A WEAK SURFACE LOW AND
STATIONARY FRONT OVER THE NORTHERN PLAINS AND UPPER MIDWEST. AT THE
SAME TIME, A WEAK COLD FRONT WILL MOVE EASTWARD OVER THE HIGH PLAINS
SERVING AS A FOCUS FOR THUNDERSTORM DEVELOPMENT FROM THE DAKOTAS AND
MN TO THE SOUTHERN PLAINS EACH AFTERNOON. SOME ISOLATED SEVERE
POTENTIAL IS APPARENT NEAR THE SURFACE LOW/STALLED FRONT OVER THE
NORTHERN PLAINS AND ALONG THE COLD FRONT FARTHER SOUTH THROUGH THE
REMAINDER OF THE WEEKEND. HOWEVER, MODEL GUIDANCE VARIES WIDELY ON
AVAILABLE MOISTURE/BUOYANCY AND THE OVERLAP WITH MORE ROBUST
VERTICAL SHEAR. THIS CONTINUES TO CAST SIGNIFICANT UNCERTAINTY ON
SEVERE PROBABILITIES THROUGH THE FIRST HALF OF THE EXTENDED FORECAST
PERIOD.
BY EARLY NEXT WEEK, MID-LEVEL RIDGING IS EXPECTED TO STRENGTHEN,
FORCING STRONGER FLOW ALOFT NORTHWARD AS THE PRIMARY WESTERN TROUGH
BEGINS TO WEAKEN. A SECOND TROUGH WILL STALL OVER THE WEST AS THE
RIDGE CONTINUES TO BUILD. THIS SHOULD FAVOR DRIER SURFACE CONDITIONS
WHILE ALSO LIMITING THE OVERLAP OF BUOYANCY WITH STRONGER FLOW
ALOFT. SEVERE POTENTIAL APPEARS LIMITED BEYOND THIS WEEKEND AND INTO
THE FIRST HALF OF NEXT WEEK.
..LYONS.. 09/10/2025
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