040
ACUS48 KWNS 110846
SWOD48
SPC AC 110844
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0344 AM CDT SAT APR 11 2026
VALID 141200Z - 191200Z
..DISCUSSION
..DAY 4/TUE -- SOUTHERN PLAINS TO GREAT LAKES
A SHORTWAVE UPPER TROUGH EMBEDDED WITHIN THE LARGER-SCALE WESTERN
U.S. TROUGH WILL EJECT ACROSS PORTIONS OF THE PLAINS TO THE UPPER
MIDWEST ON DAY 4/TUE. AS THIS OCCURS, A SURFACE LOW WILL DEEP OVER
THE CENTRAL PLAINS AND LIFT NORTHEAST ACROSS THE UPPER MIDWEST/GREAT
LAKES. SOME UNCERTAINTY REMAINS REGARDING THE EXACT EVOLUTION OF
THIS SYSTEM, MAINLY DUE TO DIFFERENCES IN MEDIUM RANGE GUIDANCE WITH
RESPECT TO SURFACE LOW PLACEMENT AND TIMING OF THE UPPER SHORTWAVE
TROUGH. NEVERTHELESS, A MOIST AND UNSTABLE AIRMASS IS EXPECTED AHEAD
OF THE LOW AND TO THE EAST OF A PLAINS DRYLINE AND SOUTH OF A GREAT
LAKES WARM FRONT. THUNDERSTORM DEVELOPMENT SHOULD BE MORE WIDESPREAD
ALONG THESE BOUNDARIES COMPARED TO PRIOR DAYS GIVEN STRONGER
LARGE-SCALE ASCENT WILL OVERSPREAD THE CENTRAL U.S., AND HEIGHT
FALLS WILL RESULT IN A MORE ROBUST LOW-LEVEL JET RESPONSE. AS A
RESULT, AN ALL-HAZARDS SEVERE EVENT IS EXPECTED FROM THE SOUTHERN
PLAINS INTO PORTIONS OF THE UPPER MIDWEST/GREAT LAKES VICINITY ON
TUESDAY/TUESDAY NIGHT.
..DAY 5/WED -- SOUTHERN PLAINS TO THE MIDWEST
MEDIUM RANGE GUIDANCE VARIES HEADING INTO WEDNESDAY WITH THE
OPERATIONAL GFS MUCH MORE PROGRESSIVE AND LOWER AMPLITUDE THAN THE
OPERATIONAL ECMWF. THE AIGFS IS MUCH MORE IN-LINE WITH THE
ECMWF/AIFS, SO THIS PERIOD IS WEIGHTED MORE TOWARD THOSE SOLUTIONS.
IT APPEARS THE UPPER TROUGH OVER THE SOUTHERN ROCKIES WILL EJECT
ACROSS THE PLAINS TO THE MID-MS VALLEY DURING THIS TIME. A MOIST AND
UNSTABLE AIRMASS WILL RESIDE ACROSS THE REGION AHEAD OF DRYLINE
ACROSS WESTERN OK INTO CENTRAL TX AND A SAGGING COLD FRONT ACROSS
THE LOWER MO/MID-MS VALLEY. AREAS OF PRECIPITATION COULD BE ONGOING
AT THE BEGINNING OF THE PERIOD AND DOES RESULT IN SOME UNCERTAINTY
REGARDING WHERE STRONGER DESTABILIZATION WILL OCCUR. NEVERTHELESS,
AN OVERALL FAVORABLE THERMODYNAMIC/KINEMATIC PARAMETER SPACE WILL
OVERLAP THIS CORRIDOR AND ISOLATED TO SCATTERED SEVERE STORMS APPEAR
LIKELY.
..DAYS 6-8/THU-SAT
MEDIUM RANGE GUIDANCE DEPICTS ANOTHER TROUGH DEVELOPING ACROSS THE
WEST ON DAY 6/THU AND QUICKLY PROGRESSING EAST THROUGH THE END OF
THE PERIOD. THIS COULD SUPPORT A CONTINUED SEVERE RISK ACROSS PARTS
OF THE SOUTHERN PLAINS INTO THE MIDWEST IN THE THURSDAY OR FRIDAY
TIME FRAME. HOWEVER, RUN TO RUN CONSISTENCY TOWARD THE END OF THE
FORECAST PERIOD HAS NOT BEEN VERY GOOD. ADDITIONALLY, MULTIPLE
ROUNDS OF STORMS ACROSS THE SAME AREAS EARLIER IN THE PERIOD MAY
IMPACT LATER SEVERE POTENTIAL. TRENDS WILL BE MONITORED AND
PROBABILITIES MAY BE NEEDED IN LATER OUTLOOKS.
..LEITMAN.. 04/11/2026
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