547
ACUS48 KWNS 230905
SWOD48
SPC AC 230904
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0404 AM CDT THU APR 23 2026
VALID 261200Z - 011200Z
..DISCUSSION
A MULTI-DAY SEVERE WEATHER EVENT REMAINS ON TRACK FOR SUNDAY/DAY-4
EVENING THROUGH MONDAY/DAY-5, WITH ADDITIONAL SEVERE STORMS POSSIBLE
DURING THE REST OF THE FORECAST PERIOD.
A VIGOROUS, YET COMPACT, NEGATIVELY TILTED MIDLEVEL WAVE IS FORECAST
TO MOVE ACROSS THE SOUTHWEST AND EJECT INTO THE PLAINS SUNDAY
EVENING INTO MONDAY. AS THIS WAVE EJECTS INTO THE CENTRAL US, STRONG
SURFACE CYCLOGENESIS IS EXPECTED OVER THE CENTRAL PLAINS ON SUNDAY
EVENING. THE FLOW AROUND THIS LOW WILL HELP DRAW VERY RICH BOUNDARY
LAYER MOISTURE NORTHWARD TO THE EAST OF A SHARPENING DRYLINE. THE
ATMOSPHERE ON SUNDAY ACROSS THE SOUTHERN AND CENTRAL PLAINS SHOULD
REMAIN CAPPED FOR MUCH OF THE DAY, ALLOWING EXTREME INSTABILITY
(SBCAPE/MUCAPE VALUES IN EXCESS OF 4000 J/KG) TO DEVELOP. AS MODEST
HEIGHT FALLS OVERSPREAD THE DRYLINE DURING THE LATE AFTERNOON AND
EVENING HOURS, THE EXPECTATION IS THAT AT LEAST A FEW STORMS WILL BE
ABLE TO BREAK THROUGH THE CAP. WHILE 20260423/00Z GLOBAL GUIDANCE IS
STILL STRUGGLING TO PRODUCE WIDESPREAD PRECIPITATION ALONG AND EAST
OF THE DRYLINE, THE CONTROL MEMBERS ARE NOW AT LEAST PRODUCING LIGHT
QPF ALONG THE DRYLINE WHICH WOULD TEND TO SUPPORT THE IDEA THAT
ISOLATED CONVECTION WILL BE POSSIBLE.
THE ENVIRONMENT TO THE EAST OF THE DRYLINE WILL BE VERY UNSTABLE AND
INCREASINGLY SHEARED AS ENHANCED MIDLEVEL FLOW OVERSPREADS THE WARM
SECTOR. ADDITIONALLY, AS THE SURFACE LOW DEEPENS DURING THE EVENING
HOURS, LOW-LEVEL WINDS WILL RESPOND BY RAPIDLY INCREASING TO GREATER
THAN 50 KNOTS. THE RESULT WILL BE THE POTENTIAL FOR ANY THUNDERSTORM
THAT DEVELOPS AND SUSTAINS ITSELF TO BECOME STRONG SUPERCELLS
CAPABLE OF PRODUCING ALL SEVERE HAZARDS, INCLUDING SIGNIFICANT
SEVERE.
AS THE MAIN WAVE CONTINUES TO LIFT NORTHEAST ON MONDAY, THE SURFACE
LOW SHOULD RAPIDLY MOVE FROM THE CENTRAL PLAINS INTO THE UPPER
MISSISSIPPI VALLEY. AS THIS OCCURS, A SURFACE WARM FRONT WILL
RAPIDLY LIFT NORTHWARD ON THE NOSE OF AN INTENSE LOW-LEVEL JET. THIS
LOW-LEVEL JET WILL LIKELY RESULT IN WIDESPREAD PRECIPITATION TO THE
NORTH OF THE FRONT, WHICH WILL HAVE IMPACTS ON THE NORTHERN EXTENT
OF MONDAY AFTERNOON'S SEVERE POTENTIAL.
BY MONDAY AFTERNOON, ADDITIONAL THUNDERSTORMS ARE EXPECTED TO
DEVELOP ALONG AND EAST OF AN ADVANCING DRYLINE/COLD FRONT IN AN
INCREASINGLY UNSTABLE ATMOSPHERE. DIURNAL HEATING OF A BOUNDARY
LAYER WITH LOW-TO-MID-60FS DEWPOINTS SHOULD RESULT IN SBCAPE/MUCAPE
VALUES BETWEEN 2000-3000 J/KG. ADDITIONALLY, VERTICAL SHEAR WILL
REMAIN MORE THAN SUFFICIENT FOR SUPERCELLS. ALL SEVERE HAZARDS WILL
REMAIN POSSIBLE WITH THIS CONVECTION, WITH THE GREATEST
CONCENTRATION OF SEVERE STORMS LIKELY ACROSS THE MID-MISSISSIPPI
VALLEY WHERE A 30% AREA WAS INTRODUCED.
MONDAY EVENING INTO THE OVERNIGHT HOURS WILL SEE A CONTINUED
POTENTIAL FOR SEVERE STORMS AS THE SURFACE FRONT PUSHES EAST INTO
THE WESTERN PORTIONS OF THE OHIO VALLEY. ADDITIONALLY, SEVERE STORMS
WILL LIKELY CONTINUE ACROSS THE SOUTHWEST PORTION OF THE FRONT,
WHICH WILL SLOWLY BEGIN TO STALL IN A SOUTHWEST-TO-NORTHEAST OR
WEST-TO-EAST CONFIGURATION ACROSS ARKANSAS INTO KENTUCKY.
ADDITIONAL SEVERE STORMS WILL BE POSSIBLE TUESDAY/DAY-6 THROUGH
THURSDAY/DAY-8 ACROSS THE SOUTHERN AND CENTRAL PLAINS INTO THE
LOWER-TO-MIDDLE MISSISSIPPI VALLEY AS CYCLONIC MIDLEVEL FLOW
PERSISTS ATOP A MOIST BOUNDARY LAYER WITH A FRONTAL BOUNDARY
SOMEWHERE ACROSS THE AREA. HOWEVER, GIVEN THE UNCERTAINTIES IN HOW
THE CONVECTIVE EVOLUTION OF SUNDAY AND MONDAY WILL IMPACT THE
LOCATION OF RELEVANT SURFACE FEATURES AND THE GENERAL UNCERTAINTY
ASSOCIATED WITH IDENTIFYING THE TIMING OF MIDLEVEL PERTURBATIONS
EMBEDDED WITHIN THE BROADER SCALE CYCLONIC MIDLEVEL FLOW,
UNCONDITIONAL 15% SEVERE PROBABILITIES WILL BE DEFERRED TO
SUBSEQUENT OUTLOOKS.
..MARSH.. 04/23/2026
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