Dec 18, 2011 1630 UTC Day 1 Convective Outlook | |
Updated: Sun Dec 18 15:56:11 UTC 2011 | |
Probabilistic to Categorical Outlook Conversion Table |
Categorical Graphic |
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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 181552 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0952 AM CST SUN DEC 18 2011 VALID 181630Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW OVER NRN BAJA WILL ACCELERATE EWD ACROSS NWRN MEXICO AND SRN PARTS OF AZ/NM IN RESPONSE TO THE APPROACH OF AN UPSTREAM SYSTEM DIGGING SEWD THROUGH THE PACIFIC NW AND NRN INTERMOUNTAIN REGION INTO GREAT BASIN. IN THE LOW LEVELS...A COLD FRONT WILL STRENGTHEN FROM THE UPPER GREAT LAKES INTO THE SRN HIGH PLAINS WHILE A SURFACE LOW DEEPENS OVER ERN NM INTO WRN TX. ...LOWER CO VALLEY INTO WRN TX/SWRN OK... THE PRIMARY FOCUS FOR TSTMS THIS PERIOD WILL BE THE CORRIDOR OF DCVA/HEIGHT FALLS PRECEDING UPPER LOW. THOUGH THE AMBIENT AIR MASS IS NOT OVERLY MOIST /PER 12Z SOUNDINGS AND GPS PW DATA/...THE FORCING FOR ASCENT WILL COINCIDE WITH THE WRN EDGE OF STEEPER MIDLEVEL LAPSE RATES...CONTRIBUTING TO WEAK CONVECTIVE INSTABILITY. ADDITIONAL ISOLATED TO WIDELY SCATTERED TSTMS WILL BE POSSIBLE WELL DOWNSTREAM OF UPPER SYSTEM TODAY OVER WRN TX WHERE STRENGTHENING LOW-LEVEL WAA WILL ALIGN WITH THE STEEP LAPSE RATES AND WRN EXTENT OF A MODIFIED CP AIR MASS RETURNING FROM THE NWRN GULF OF MEXICO. NO SEVERE WEATHER IS EXPECTED. ..MEAD.. 12/18/2011 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z