465
ACUS48 KWNS 300902
SWOD48
SPC AC 300900
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0400 AM CDT THU APR 30 2026
VALID 031200Z - 081200Z
..DISCUSSION
LATE THIS COMING WEEKEND INTO EARLY NEXT WEEK, IT STILL APPEARS THAT
AT LEAST A TRANSIENT BLOCKING HIGH MAY CONTINUE TO EVOLVE OFFSHORE
OF THE BRITISH COLUMBIA/PACIFIC NORTHWEST COAST. IT REMAINS A BIT
UNCERTAIN HOW LONG THIS WILL PERSIST BEFORE BECOMING SUPPRESSED, AND
AN EVOLVING LOW TO ITS SOUTHEAST IS FORCED INLAND ACROSS SOUTHERN
CALIFORNIA INTO THE SOUTHWEST.
LATEST MEDIUM RANGE GUIDANCE CONTINUES TO INDICATE THAT IT IS
POSSIBLE THAT A SHORT WAVE PERTURBATION COULD EMERGE FROM THE
REMNANT LOW/TROUGHING, IN ADVANCE OF ANOTHER SIGNIFICANT SHORT WAVE
IMPULSE EMERGING FROM THE HIGHER LATITUDES BEFORE AMPLIFYING
SOUTHEASTWARD TO THE LEE OF THE ROCKIES, THROUGH THE ATLANTIC
SEABOARD BY THE END OF THE PERIOD. HOWEVER, IT NOW APPEARS PROBABLE
THAT MODEST TROUGHING, PERHAPS WITH A CONTINUING CYCLONIC
CIRCULATION, WILL LINGER NEAR AND SOUTH OF THE SOUTHWESTERN
INTERNATIONAL BORDER.
IN LOWER LEVELS, SOUTHERLY MOIST RETURN FLOW MAY COMMENCE BY EARLY
NEXT WEEK ACROSS THE SOUTHERN INTO CENTRAL GREAT PLAINS AS SURFACE
TROUGHING DEEPENS TO THE LEE OF THE ROCKIES. THIS MAY BEGIN TO MORE
SUBSTANTIVELY ADVECT NORTHEASTWARD TOWARD THE OHIO VALLEY, IN
ADVANCE OF A SOUTHWARD ADVANCING COLD FRONT ASSOCIATED WITH THE
DIGGING MID-LEVEL TROUGHING. HOWEVER, THERE IS NOTABLE SPREAD AMONG
THE MODEL OUTPUT CONCERNING POTENTIAL SURFACE CYCLOGENESIS, NEAR
AND NORTHEAST OF THE ROCKIES.
WIDELY SCATTERED STRONG TO SEVERE THUNDERSTORM DEVELOPMENT APPEARS
POSSIBLE FROM PARTS OF THE CENTRAL AND SOUTHERN GREAT PLAINS INTO
THE MISSISSIPPI VALLEY BY TUESDAY, IF NOT MONDAY. HOWEVER,
INHIBITION ASSOCIATED WITH WARM ELEVATED MIXED-LAYER AIR
OVERSPREADING THE SOUTHERN GREAT PLAINS MAY BECOME A LIMITING
FACTOR, AS LOW-LEVEL MOISTURE BECOMES MORE SUPPORTIVE OF STRONG
DESTABILIZATION.
THERE REMAINS AT LEAST SOME SIGNAL IN THE MODEL OUTPUT FOR
POTENTIALLY MORE WIDESPREAD STRONG TO SEVERE THUNDERSTORM
DEVELOPMENT ACROSS THE LOWER/MIDDLE MISSISSIPPI VALLEY INTO OHIO
VALLEY BY NEXT WEDNESDAY, PERHAPS INTO THURSDAY. HOWEVER, WITH
UNCERTAINTIES REMAINING SIZABLE AT THIS EXTENDED TIME FRAME, SEVERE
PROBABILITIES STILL APPEAR LESS THAN 15 PERCENT.
..KERR.. 04/30/2026
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