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| Probabilistic Tornado Graphic | |||||||||
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| Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point. |
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| Probabilistic Damaging Wind Graphic | |||||||||
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| Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point. |
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| Probabilistic Large Hail Graphic | |||||||||
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| Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point. |
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SPC AC 270612 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0112 AM CDT MON MAY 27 2013 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE HIGH PLAINS TO THE LOWER/MIDDLE MO VALLEY AND MIDWEST... CORRECTED FOR OUTLOOK WORDING ...CENTRAL PLAINS/MO VALLEY TO MIDWEST/MIDDLE MS VALLEY... SCATTERED LINEAR-TYPE CLUSTERS AND PERHAPS EVEN A LINGERING SEMI-SUSTAINED/ORGANIZED MCS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD ACROSS THE MIDDLE/LOWER MO VALLEY TO THE MIDDLE MS VALLEY VICINITY. ASSOCIATED CONVECTIVE OUTFLOW ACROSS PARTS OF NEB/KS INTO IA/NORTHERN MO WILL LIKELY BE A KEY FACTOR FOR EFFECTIVELY DEFINING/REINFORCING A ROUGHLY WEST-EAST BAROCLINIC ZONE LATER TODAY. ASIDE FROM WHAT MAY BE AN EPISODIC WIND/HAIL THREAT ACROSS PARTS OF THE MIDWEST/MIDDLE MS VALLEY/LOWER OH VALLEY DURING THE DAY...A MORE CONSEQUENTIAL SEVERE RISK IS EXPECTED TO EVOLVE ACROSS THE CENTRAL PLAINS/MO VALLEY FROM MID/LATE AFTERNOON INTO THIS EVENING. THIS SCENARIO WILL BE AIDED A SUBTLY CYCLONIC BELT OF MID-HIGH LEVEL WESTERLIES AND A POTENTIAL APPROACHING/EMBEDDED SHORTWAVE IMPULSE OR TWO. THE MOST PROBABLE AREA FOR INITIAL SURFACE BASED STORM DEVELOPMENT APPEARS TO BE ALONG AN OUTFLOW-AIDED/EFFECTIVE BOUNDARY INDUCED TRIPLE POINT NEAR/EAST OF A WEST-CENTRAL/NORTH-CENTRAL KS SURFACE LOW. THIS INCLUDES PARTS OF CENTRAL/NORTHERN KS INTO SOUTHERN NEB. WITH MIDDLE/UPPER 60S F AND PERHAPS EVEN SOME NEAR 70 F SURFACE DEWPOINTS BENEATH A VERY STEEP ELEVATED MIXED LAYER PLUME /MID-LEVEL RATES LIKELY EXCEEDING 8 DEG PER KM/...THE BOUNDARY LAYER WILL LIKELY BECOME STRONGLY UNSTABLE BY AFTERNOON...WITH MLCAPES LIKELY TO REACH 3000-4000 J/KG ESPECIALLY ACROSS CENTRAL KS AND POTENTIALLY INTO FAR SOUTHERN NEB/WESTERN MO. IT SHOULD ALSO BE NOTED THAT A SOMEWHAT SEPARATE AREA FOR ADDITIONAL SEVERE TSTM DEVELOPMENT...INCLUDING A COUPLE OF SUPERCELLS...MAY OCCUR THIS AFTERNOON/EARLY EVENING ACROSS WESTERN KS/FAR SOUTHWEST NEB NEAR THE ANGLING BAROCLINIC ZONE WITHIN THE NORTHWEST QUADRANT OF THE WESTERN KS SURFACE LOW. BASED ON SOME EXPECTED TROUGH AMPLIFICATION AND UPSTREAM EVENING SOUNDING OBSERVATIONS OVER THE WESTERN CONUS...A BIT STRONGER /BY 5-10 KT/ WEST-SOUTHWESTERLY MID-HIGH LEVEL FLOW SEEMS PROBABLE ACROSS THE CENTRAL PLAINS/MO VALLEY WARM SECTOR. ACCORDINGLY...EFFECTIVE BULK SHEAR OF AT LEAST 35-45 KT WILL LIKELY EXIST ACROSS THE WARM SECTOR...WITH EVEN STRONGER VALUES ALONG THE WSW-ENE EFFECTIVE BOUNDARY. THIS WILL SUPPORT THE POSSIBILITY OF SOME INTENSE SUPERCELLS WITH VERY LARGE HAIL...ALONG WITH THE POSSIBILITY OF TORNADOES...ONE OR TWO POSSIBLY STRONG GIVEN AN EXPECTED EARLY EVENING LOW LEVEL JET INCREASE AND ASSOCIATED LENGTHENING/CURVING LOW-LEVEL HODOGRAPHS. AIDED BY THIS STRENGTHENING LOW-LEVEL JET...STORMS SHOULD ULTIMATELY GROW UPSCALE AND PROPAGATE EAST OR PERHAPS A BIT SOUTHEASTWARD TOWARD/ACROSS PARTS OF EASTERN KS/SOUTHERN NEB INTO MO/SOUTHERN IA. GIVEN SUCH...DAMAGING WIND POTENTIAL WOULD INCREASE ASIDE FROM CONTINUED BOUTS OF SEVERE HAIL THROUGH THE LATE EVENING/OVERNIGHT HOURS. ...NORTHERN HIGH PLAINS... A NORTHEASTWARD-MOVING SHORTWAVE TROUGH OVER THE NORTHERN ROCKIES WILL CONTINUE EAST-NORTHEASTWARD TODAY AND CONTRIBUTE TO PERSISTENT TSTMS INCLUDING A SEMI-ORGANIZED SEVERE THREAT ESPECIALLY THIS AFTERNOON THROUGH EARLY/MID-EVENING. THIS INCLUDES THE POSSIBILITY OF SOME SUPERCELLS MAINLY CAPABLE OF SEVERE HAIL...ALONG WITH SOME DAMAGING WIND THREAT AS STORMS CONGEAL INTO LINES/CLUSTERS BY THIS EVENING. ...SOUTHERN HIGH PLAINS... ISOLATED TO PERHAPS WIDELY SCATTERED TSTMS WILL BE POSSIBLE LATE THIS AFTERNOON/EARLY EVENING ALONG THE SOUTHERN HIGH PLAINS DRYLINE. DEEP LAYER VERTICAL SHEAR WILL GENERALLY BE RELATIVELY MODEST /30 KT OR SO/...ALTHOUGH A BIT STRONGER FLOW ALOFT POSSIBLY ACROSS NORTHWEST TX INTO WESTERN OK...ALONG WITH AT LEAST A MODERATELY UNSTABLE BOUNDARY LAYER...WILL SUPPORT THE POSSIBILITY OF SOME SUPERCELLS CAPABLE OF LARGE HAIL/LOCALLY DAMAGING WINDS. ..GUYER/GRAMS.. 05/27/2013 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z |