Jul 22, 2012 1630 UTC Day 1 Convective Outlook | |
Updated: Sun Jul 22 16:32:28 UTC 2012 | |
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 221628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT SUN JUL 22 2012 VALID 221630Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NORTHERN MN INTO PARTS OF NORTHERN WI AND UPPER MI... ...MN/WI/UPPER MI... MORNING WATER VAPOR IMAGERY SHOWS A WEAK LEAD SHORTWAVE TROUGH MOVING ACROSS NORTHERN MN...WHILE A SECOND AND STRONGER IMPULSE APPROACHES FROM THE NORTHWEST. THIS SECOND FEATURE WILL BEGIN AFFECTING NORTHERN MN BY LATE AFTERNOON. WEAK SOUTHERLY LOW LEVEL WINDS WILL TRANSPORT NEAR 70F DEWPOINTS NORTHWARD TO NEAR THE INTERNATIONAL BORDER...YIELDING MLCAPE VALUES OF OVER 2000 J/KG. PRESENT INDICATIONS ARE THAT AT LEAST ISOLATED THUNDERSTORMS WILL DEVELOP ALONG THE APPROACHING COLD FRONT OVER NORTHERN MN BEFORE EARLY EVENING. EFFECTIVE SHEAR ACROSS THIS REGION WILL BE SUFFICIENT FOR SUPERCELLS CAPABLE OF DAMAGING WINDS AND HAIL. STORMS WILL STRUGGLE TO DEVELOP VERY FAR SOUTHWARD INTO CENTRAL/SOUTHERN MN DUE TO CAPPING AND WEAK FORCING. HOWEVER...THEY MAY PERSIST WELL INTO THE EVENING AND SPREAD ACROSS PARTS OF LAKE SUPERIOR AND NORTHERN UPPER MI. ...SOUTHEAST STATES... VISIBLE SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES TODAY OVER MUCH OF THE SOUTHEAST STATES FROM NC INTO THE FL PANHANDLE. SURFACE DEWPOINTS IN THE MID 70S...AND HOT AFTERNOON TEMPERATURES/STEEP LOW LEVEL LAPSE RATES WILL RESULT IN WIDESPREAD MUCAPE VALUES OVER 3000 J/KG. THE GREATEST COVERAGE OF THUNDERSTORMS IS EXPECTED ALONG A DIFFERENTIAL HEATING BOUNDARY OVER NC...AND AHEAD OF THE TROPICAL WAVE OVER CENTRAL FL. ANY STORM THAT FORMS ACROSS THIS REGION TODAY WILL POSE A RISK OF BRIEF BUT LOCALLY DAMAGING WINDS. ...TX... ANOTHER ROUND OF ISOLATED TO SCATTERED AFTERNOON THUNDERSTORMS IS EXPECTED TODAY OVER PARTS OF CENTRAL TX. A WEAK UPPER LOW IS APPARENT IN WATER VAPOR LOOPS ACROSS THE REGION...ALONG WITH MORE CLOUD DEBRIS THAT THE LAST FEW DAYS. THE ENHANCED CLOUDS MAY DECREASE DAYTIME HIGHS BY A FEW DEGREES AND SOMEWHAT MITIGATE THE MICROBURST POTENTIAL. NEVERTHELESS...ISOLATED INTENSE STORMS WITH LOCALLY DAMAGING WINDS ARE POSSIBLE. ...NORTHERN HIGH PLAINS... A PLUME OF RATHER DEEP MOISTURE IS EVIDENT IN WATER VAPOR IMAGERY EXTENDING ACROSS WY INTO SD TODAY. THIS COMBINED WITH STRONG DAYTIME HEATING AND AN AXIS OF LOW LEVEL MOISTURE WILL AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS LATER THIS AFTERNOON AND EVENING. MID LEVEL WINDS AND DEEP LAYER SHEAR ARE WEAKER THAN YESTERDAY...SUGGESTING STORMS WILL BE LESS ORGANIZED. HOWEVER...STRONGER STORMS IN THIS AREA WILL POSE A RISK OF GUSTY WINDS AND HAIL. ...MT... SCATTERED THUNDERSTORMS ARE EXPECTED TO FORM THIS AFTERNOON OVER THE MOUNTAINS OF SOUTHWEST MT...AHEAD OF AN APPROACHING UPPER TROUGH OVER WA/ORE...AND A SUBTLE VORT MAX LIFTING NORTHWARD ACROSS NV. SUFFICIENT VERTICAL SHEAR AND A RATHER DRY SUB-CLOUD LAYER WILL PROMOTE A FEW ORGANIZED STORMS CAPABLE OF LOCALLY DAMAGING WINDS AND HAIL. ..HART/COHEN.. 07/22/2012 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z