144
ACUS03 KWNS 220722
SWODY3
SPC AC 220721
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0221 AM CDT WED APR 22 2026
VALID 241200Z - 251200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY...
..SUMMARY
A FEW SEVERE THUNDERSTORMS WILL BE POSSIBLE ACROSS PORTIONS OF THE
SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY ON SATURDAY. LARGE
HAIL AND DAMAGING WIND GUSTS SHOULD BE THE PRIMARY THREATS.
.. SYNOPSIS
A PERSISTENT LONGWAVE TROUGH WILL REMAIN SITUATED ACROSS THE
NORTHERN US ON FRIDAY, MAINTAINING A BROAD REGIME OF CYCLONIC
MIDLEVEL FLOW OVER THE WESTERN TWO-THIRDS OF THE COUNTRY. WITHIN
THIS BROAD FLOW, NEUTRAL TO MODEST MIDLEVEL HEIGHT RISES ARE LIKELY
ACROSS THE SOUTHERN PLAINS. THIS EVOLUTION SUGGESTS A LACK OF ROBUST
LARGE-SCALE FORCING FOR ASCENT, WITH SUBTLE SUBSIDENCE POTENTIALLY
ACTING AS A LIMITING FACTOR FOR WIDESPREAD CONVECTIVE COVERAGE.
.. SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY
AT THE START OF THE FORECAST PERIOD, CONVECTIVE ACTIVITY MAY BE
ONGOING ACROSS PORTIONS OF NORTHEAST OKLAHOMA, SOUTHEAST KANSAS,
SOUTHERN MISSOURI, OR NORTHERN ARKANSAS ALONG A CONSOLIDATED OUTFLOW
BOUNDARY/COLD FRONT. THESE STORMS SHOULD SLOWLY WEAKEN DURING THE
MORNING WITH THE LOSS OF LARGE-SCALE ASCENT AND A WEAKENING
LOW-LEVEL JET. THE OUTFLOW BOUNDARY/COLD FRONT SHOULD SLOWLY SAG
SOUTH THROUGH THE MORNING BEFORE STALLING SOMEWHERE IN THE VICINITY
OF THE I40 CORRIDOR. THIS FEATURE WILL SERVE AS THE PRIMARY FOCUS
FOR SUBSEQUENT DEVELOPMENT LATER IN THE AFTERNOON, WITH RESIDUAL
OUTFLOW OR DIFFERENTIAL HEATING BOUNDARIES BEING A SECONDARY SOURCE
OF INITIATION.
SOUTH OF THE FRONTAL BOUNDARY, A HIGHLY UNSTABLE AIRMASS WILL REMAIN
IN PLACE ACROSS THE WARM SECTOR. STRONG DIABATIC HEATING OF A MOIST
BOUNDARY LAYER WILL YIELD POCKETS OF MODERATE-TO-STRONG INSTABILITY,
WITH MUCAPE VALUES POTENTIALLY IN THE 2000-3000 J/KG RANGE. WHILE
DEEP-LAYER SHEAR IS FORECAST TO REMAIN RELATIVELY MODEST (30-35
KNOTS), THE DEGREE OF INSTABILITY WILL BE SUFFICIENT TO SUPPORT
ROBUST UPDRAFTS.
GIVEN THE MODEST SHEAR AND LACK OF STRONGER SYNOPTIC SUPPORT, STORM
MODES WILL LIKELY BE MULTICELL CLUSTERS OR TRANSIENT SUPERCELLS. ANY
PERSISTENT CELL WILL BE CAPABLE OF PRODUCING LARGE HAIL AND
LOCALIZED DAMAGING WIND GUSTS
.. LOWER MISSISSIPPI VALLEY
CONVECTION THAT DEVELOPS ACROSS OKLAHOMA AND ARKANSAS DURING THE
AFTERNOON IS EXPECTED TO PERSIST INTO THE EVENING AS IT MOVES SLOWLY
EAST-SOUTHEAST TOWARD MISSISSIPPI AND TENNESSEE. ALTHOUGH
INSTABILITY IS NOT AS GREAT WITH EASTWARD EXTENT, IT SHOULD REMAIN
SUFFICIENT ENOUGH TO SUPPORT SOME POTENTIAL FOR SPORADIC WIND AND
HAIL THROUGH THE OVERNIGHT HOURS.
..MARSH.. 04/22/2026
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