| 
)| Apr 23, 2014 2000 UTC Day 1 Convective Outlook |
| Updated: Wed Apr 23 19:56:37 UTC 2014 ( | ) |
| Probabilistic to Categorical Outlook Conversion Table |
| Categorical Graphic | |||||||||
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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 231953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0253 PM CDT WED APR 23 2014 VALID 232000Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE PLAINS FROM SRN NEB SWD INTO THE NWRN TX VICINITY... ...SUMMARY... SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON INTO TONIGHT ACROSS PARTS OF THE CENTRAL AND SOUTHERN GREAT PLAINS. LARGE HAIL WILL BE THE PRIMARY INITIAL HAZARD...WITH DAMAGING WINDS AND A FEW TORNADOES ALSO POSSIBLE. ...DISCUSSION... MINIMAL CHANGES ARE REQUIRED THIS UPDATE AS PRIOR REASONING REMAINS VALID. STORM DEVELOPMENT IS EXPECTED ACROSS THE PLAINS OVER THE NEXT COUPLE OF HOURS...WITH HAIL/WIND RISK ANTICIPATED. TORNADO RISK -- WHILE LIMITED OVERALL GIVEN A RELATIVELY DEEP MIXED LAYER -- WOULD APPEAR TO BE GREATEST OVER THE SWRN OK/WRN N TX VICINITY VERY LATE THIS AFTERNOON AND INTO EARLY THIS EVENING BEFORE DIMINISHING. FOR ADDITIONAL SHORT-TERM INFORMATION...PLEASE REFER TO RECENTLY ISSUED SWOMCD NUMBERS 385 AND 386. ..GOSS.. 04/23/2014 .PREV DISCUSSION... /ISSUED 1127 AM CDT WED APR 23 2014/ ...SYNOPTIC SETUP... PROGRESSIVE/MODERATELY AMPLIFIED PATTERN WILL PREVAIL THIS PERIOD...WITH GRT BASIN TROUGH THE MAIN FACTOR AFFECTING SVR WEATHER POTENTIAL INTO THU. THE TROUGH SHOULD CONTINUE E TO THE HIGH PLNS BY 12Z THU AS DOWNSTREAM RIDGE REACHES THE LWR OH VLY. WITHIN THE TROUGH...MAIN SHORTWAVE IMPULSE NOW ENTERING THE LWR CO VLY SHOULD PIVOT E TO THE AZ-NM BORDER THIS EVE AND INTO W TX EARLY THU. AT THE SAME TIME...WEAKER DOWNSTREAM IMPULSE OVER NM SHOULD LIFT NE ACROSS THE CNTRL HIGH PLNS TODAY AND INTO THE MID MO VLY EARLY THU. IN THE NRN PART OF THE TROUGH...DISTURBANCE NOW OVER WY WILL TRACK NE INTO ND BY EVE...ADVANCING AN ASSOCIATED COLD FRONT ESEWD ACROSS THE CNTRL PLNS. FARTHER S...LEE TROUGH/DRY LINE SEGMENTS SHOULD MIX E INTO WRN PORTIONS OF CNTRL AND SRN PLNS THIS AFTN...BEFORE BEING OVERTAKEN BY THE COLD FRONT TNGT/EARLY THU. BOTH THE CNTRL PLNS COLD FRONT AND THE DRY LINE/LEE TROUGH SEGMENTS FARTHER S WILL PROMOTE STRONG TO SVR STORM DEVELOPMENT...BEGINNING THIS AFTN AND CONTINUING INTO TNGT. ...CNTRL PLNS COLD FRONT THIS AFTN/EVE... TSTMS SHOULD FORM ALONG COLD FRONT FROM S CNTRL/SE SD SWWD INTO NW KS AS THE BOUNDARY ACCELERATES ESEWD. CURRENT OBSERVATIONS SUGGEST THAT MOISTURE WILL REMAIN SOMEWHAT LIMITED...WITH PW AROUND 1 INCH AND AVERAGE SFC DEWPOINTS AROUND 50 F. LOW TO MID-LVL LAPSE RATES WILL...HOWEVER...BE FAIRLY STEEP...CONTRIBUTING TO MLCAPE ON THE ORDER OF 500 J/KG IN NERN NEB TO ABOVE 1000 J/KG IN NW KS. DEEP SHEAR WILL VARY ACROSS THE REGION...RANGING FROM 40 KT WSWLY IN KS TO 50 KT SSWLY IN NRN NEB. OVERALL SETUP APPEARS FAVORABLE FOR RELATIVELY HIGH-BASED SUSTAINED STORMS/SUPERCELLS CAPABLE OF DMGG WIND AND HAIL AS NRN STREAM IMPULSE GLANCES REGION AND WEAKER DISTURBANCE APPROACHES FROM THE SW. THE ACTIVITY SHOULD MERGE INTO AN ESE-MOVING MCS IN SRN NEB/NRN KS BY EARLY TNGT. A GRADUALLY DIMINISHING DMGG WIND THREAT MAY PERSIST IN ASSOCIATION WITH EMBEDDED FORWARD-PROPAGATING SEGMENTS/SMALL BOWS THROUGH EARLY THU. ...CNTRL/SRN PLNS LEE TROUGH/DRY LINE THIS AFTN INTO TNGT... CLOUDS ASSOCIATED WITH LEAD UPR IMPULSE SHOULD CLEAR REGION ALONG LEE TROUGH/DRY LINE SEGMENTS OVER WRN PARTS OF THE CNTRL AND SRN PLNS BY EARLY AFTN...ALLOWING FOR SUBSTANTIAL HEATING. AT THE SAME TIME...BOUNDARY LAYER MOISTURE SHOULD CONTINUE TO SLOWLY INCREASE THROUGH ADVECTION. SFC DEWPOINTS SHOULD AVERAGE IN THE UPR 50S TO AROUND 60 OVER W TX...WITH SOMEWHAT LWR VALUES EXTENDING NWD INTO WRN KS. COUPLED WITH STEEP MID-LVL LAPSE RATES...EXPECT MUCAPE TO RANGE FROM 1000 J/KG IN KS TO 2000 J/KG IN TX. SFC HEATING AND HEIGHT FALLS ASSOCIATED WITH PROGRESSIVE NATURE OF LARGE-SCALE TROUGH SHOULD FOSTER SCTD STORM DEVELOPMENT ALONG LEE TROUGH/DRY LINE SEGMENTS BEGINNING LATE THIS AFTN AND CONTINUING INTO TNGT FROM WRN KS TO W CNTRL TX. MORE WDLY SCTD ACTIVITY MAY EXTEND S TO THE TX BIG BEND. COUPLED WITH 40-45 KT WSWLY DEEP SHEAR AND STEEP MID-LVL LAPSE RATES...ENVIRONMENT SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL...SOME POSSIBLY VERY LARGE...AND LOCALLY DMGG WIND. A RISK FOR TORNADOES ALSO MAY DEVELOP...PARTICULARLY THIS EVE/EARLY TNGT OVER NW TX/SW OK...AS NOCTURNAL AND DYNAMIC STRENGTHENING OF SLY LLJ ENLARGES HODOGRAPHS. THIS WINDOW OF OPPORTUNITY SHOULD DIMINISH LATER TNGT AS THE STORMS MERGE INTO SHORT LINE/CLUSTERS...ALTHOUGH A LIMITED RISK FOR SVR WIND/HAIL MAY PERSIST NEAR THE RED RVR THROUGH EARLY THU. CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z |