| 
)| Apr 13, 2014 2000 UTC Day 1 Convective Outlook |
| Updated: Sun Apr 13 20:02:36 UTC 2014 ( | ) |
| Probabilistic to Categorical Outlook Conversion Table |
| Categorical Graphic | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
|||||||||
| Probabilistic Tornado Graphic | |||||||||
 |
|||||||||
| 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. |
|||||||||
| Probabilistic Damaging Wind Graphic | |||||||||
 |
|||||||||
| 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. |
|||||||||
| Probabilistic Large Hail Graphic | |||||||||
 |
|||||||||
| 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. |
|||||||||
| |||||||||
SPC AC 131959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT SUN APR 13 2014 VALID 132000Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MO/MID-MS VALLEY TO THE SRN PLAINS/LOWER MS VALLEY... ...DISCUSSION... ISOLATED TO SCATTERED SEVERE STORMS ARE UNDERWAY FROM THE LOWER MO VALLEY TO THE SRN PLAINS AND WILL SPREAD EWD TO THE LOWER/MID-MS VALLEYS THROUGH TONIGHT. WIDESPREAD CONVECTION FROM NERN KS INTO NRN OK HAS QUICKLY BECOME LINEAR WITHIN STRONG LOW-LEVEL CONVERGENCE ALONG THE SURFACE COLD FRONT. EMBEDDED SUPERCELLS AND BOWING STRUCTURES WILL BE CAPABLE OF SWATHS OF SEVERE HAIL/WIND. THE ERN EXTENT OF HIGHER COVERAGE PROBABILITIES IS STILL UNCERTAIN GIVEN ABUNDANT CLOUDINESS AND ONGOING SHOWERS/NON-SEVERE STORMS FORM NERN TX INTO MO. FARTHER S ALONG THE DRYLINE...ISOLATED TO SCATTERED DISCRETE CONVECTION IS APPARENT FROM CNTRL OK TO THE EDWARDS PLATEAU OF W TX. THE NRN PORTION OF THIS ACTIVITY WILL HAVE THE GREATEST RISK FOR SIGNIFICANTLY-SIZED LARGE HAIL ALONG WITH A COUPLE OF TORNADOES...WITH STRONGER LOW-LEVEL SHEAR AND STEEPER MID-LEVEL LAPSE RATES. WITH TIME...OVERTAKING OF THE DRYLINE WITH THE COLD FRONT WILL YIELD PREDOMINATELY LINEAR CONVECTION AND A MIXED WIND/HAIL RISK. ACROSS THE ARKLATEX TO LOWER MS VALLEY...LOW CONFIDENCE REMAINS OVER HOW EXACTLY THE SEVERE RISK WILL EVOLVE THIS AFTERNOON INTO TONIGHT GIVEN ONGOING NON-SEVERE CONVECTION LIMITING WARM SECTOR DESTABILIZATION. GREATEST LOW-LEVEL WAA IS EXPECTED TO BECOME CENTERED OVER THE LOWER MS VALLEY TONIGHT. THIS SHOULD SUPPORT AT LEAST SOME POTENTIAL FOR AN ORGANIZED MCS...POSSIBLY EVOLVING WITH THE LEAD CONVECTION OR EMANATING FROM SUPERCELLS ALONG THE DRYLINE. ..GRAMS.. 04/13/2014 .PREV DISCUSSION... /ISSUED 1119 AM CDT SUN APR 13 2014/ MORNING SURFACE ANALYSIS SHOWS A DEEP LOW OVER SOUTH-CENTRAL KS...WITH A COLD FRONT SURGING SOUTHEASTWARD ACROSS NORTHWEST OK. A DRYLINE EXTENDS SOUTHWARD FROM THE LOW ACROSS WESTERN OK...AND A WARM FRONT EXTENDS NORTHEASTWARD FROM THE LOW INTO NORTHEAST KS. ALL OF THESE BOUNDARIES WILL HELP TO FOCUS STRONG TO SEVERE THUNDERSTORM ACTIVITY LATER TODAY. ...EASTERN KS/WESTERN MO... CLOUDS ARE ERODING ACROSS EASTERN KS..AHEAD OF THE SURFACE LOW. DEWPOINTS IN THE LOW 60S COUPLED WITH AFTERNOON TEMPS IN THE 70S WILL YIELD MLCAPE VALUES OF 2000+ J/KG AND A WEAK CAP. THUNDERSTORMS ARE EXPECTED TO DEVELOP RATHER EARLY THIS AFTERNOON AND SPREAD EASTWARD INTO WESTERN MO. STEEP MID LEVEL LAPSE RATES AND SUFFICIENT DEEP LAYER FLOW WILL PROMOTE ORGANIZED/SUPERCELL STORMS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. A RATHER STRONG SOUTHERLY LOW LEVEL JET ALSO SUGGESTS SOME RISK OF AN ISOLATED TORNADO OR TWO. THE EASTWARD EXTENT OF THIS THREAT THIS EVENING IS UNCERTAIN DUE TO ONGOING PRECIPITATION AND CLOUDS OVER MO...BUT WILL MAINTAIN SLIGHT RISK IN THIS REGION IN THE EVENT THAT DESTABILIZATION CAN OCCUR. REFER TO SWOMCD NUMBER 333 FOR FURTHER DETAILS. ...OK/WESTERN AR... 12Z MODEL SOLUTIONS ARE CONVERGING ON A SCENARIO WHERE ISOLATED STORMS DEVELOP IN THE 19-21Z TIME FRAME ALONG THE COLD FRONT/DRYLINE OVER CENTRAL OK. THESE STORMS WILL LIKELY BECOME RAPIDLY SEVERE AND TRACK EASTWARD ACROSS EASTERN OK INTO WESTERN AR DURING THE LATE AFTERNOON/EVENING. THERMODYNAMIC PARAMETERS APPEAR FAVORABLE FOR SEVERE/SIGNIFICANT HAIL IN THE STORMS THAT FORM. ACTIVITY THAT DEVELOPS ALONG THE DRYLINE HAS A BETTER CHANCE OF STAYING DISCRETE OVER SOUTHEAST OK...POSING A GREATER RISK OF A FEW TORNADOES. MOST MODEL GUIDANCE SUGGESTS THE STORMS MAY ORGANIZE INTO A SQUALL LINE THIS EVENING WITH AN ENHANCED THREAT OF DAMAGING WINDS AS THEY MOVE INTO AR. ...CENTRAL TX... CONVECTIVE DEVELOPMENT SOUTHWARD ALONG THE DRYLINE INTO CENTRAL TX IS MORE UNCERTAIN AND LIKELY MORE SPARSE. NEVERTHELESS...AN ISOLATED SEVERE STORM OR TWO IS POSSIBLE THIS AFTERNOON ROUGHLY ALONG AN AXIS FROM GNV-SEP-JCT. LARGE HAIL AND DAMAGING WINDS WOULD BE THE MAIN THREAT. ...AR/EAST TX/LA/MS... SEVERAL MODEL SOLUTIONS ARE SUGGESTING THAT THE PRECIPITATION SHIELD CURRENTLY AFFECTING PARTS OF EAST TX WILL INTENSIFY THIS AFTERNOON WITH A FEW EMBEDDED SEVERE STORMS. WHILE THIS SCENARIO IS PLAUSIBLE...IT IS FAR FROM CERTAIN. LOW LEVEL AND DEEP LAYER VERTICAL SHEAR PROFILES WILL SUPPORT SUPERCELL STORMS...AND SUFFICIENT LOW LEVEL MOISTURE IS PRESENT FOR A RISK OF ISOLATED TORNADOES. THIS THREAT WILL PERSIST THROUGH THE EVENING AND OVERNIGHT AS THE CONVECTION SPREADS EASTWARD ACROSS THE ARKLATEX REGION INTO MS. CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z |