Feb 16, 2006 2000 UTC Day 1 Convective Outlook Updated: Thu Feb 16 19:56:10 UTC 2006 Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
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SPC AC 161952 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0152 PM CST THU FEB 16 2006 VALID 162000Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EARLY EVE ACROSS PARTS OF THE MID MS AND LWR OH VLYS.... ...OZARK PLATEAU INTO GREAT LAKES.... WAVE SHIFTING NORTHEASTWARD ALONG SHARP FRONTAL ZONE THROUGH THE MIDDLE MISSISSIPPI VALLEY IS STILL RELATIVELY LOW IN AMPLITUDE. HOWEVER...MODELS CONTINUE TO SUGGEST SURFACE LOW WILL BECOME BETTER DEFINED LATER THIS AFTERNOON ACROSS NORTHEASTERN ILLINOIS/NORTHERN INDIANA...BEFORE MORE RAPID DEEPENING OCCURS AS IT PROGRESSES INTO THE LOWER GREAT LAKES REGION LATER TONIGHT. THIS WILL OCCUR IN RESPONSE TO EAST NORTHEASTWARD PROPAGATION OF A 100+ KT 500 MB JET OUT OF THE SOUTH CENTRAL HIGH PLAINS. IN WAKE OF THE LOW...COLD FRONT WILL SURGE SOUTHEAST OF THE MIDDLE MISSISSIPPI VALLEY/OZARK PLATEAU REGION...WITH ASSOCIATED FORCING PROVIDING FOCUS FOR EVOLUTION OF A SQUALL LINE BY EARLY EVENING. INITIATION OF THIS PROCESS ALREADY APPEARS UNDERWAY FROM PARTS OF CENTRAL ILLINOIS THROUGH SOUTHWESTERN MISSOURI. NARROW PLUME OF ELEVATED MIXED LAYER AIR...EMANATING FROM THE SOUTHERN PLATEAU...EXTENDS AHEAD OF FRONT...ACROSS THE OZARK PLATEAU INTO THE LOWER OHIO VALLEY. THIS IS CONTRIBUTING TO A CORRIDOR OF CONVECTIVE INSTABILITY WHICH WILL SUPPORT THE DEVELOPMENT OF SEVERE THUNDERSTORMS. GIVEN BOUNDARY LAYER DEW POINTS IN THE MID/UPPER 50S...AS FORCING WEAKENS MID-LEVEL INHIBITION LATE THIS AFTERNOON...CAPE APPEARS LIKELY TO EXCEED 500 J/KG. WITH DEEP LAYER SHEAR ALREADY VERY STRONG AND SUPPORTIVE OF SUPERCELLS...LOW-LEVEL HODOGRAPHS ALONG STRENGTHENING PRE-FRONTAL SOUTHERLY LOW-LEVEL JET AXIS WILL BECOME INCREASINGLY FAVORABLE FOR TORNADOES. JUXTAPOSITION OF STRONGER SHEAR/BOUNDARY LAYER BASED INSTABILITY SUGGESTS BEST POTENTIAL FOR TORNADOES MAY EXIST FROM PARTS OF NORTHERN ARKANSAS/SOUTHEAST MISSOURI INTO SOUTHERN ILLINOIS. HOWEVER...DESPITE SOMEWHAT WEAKER INSTABILITY IN CLOSER PROXIMITY TO SURFACE LOW...AMBIENT VERTICAL VORTICITY AND STRONG FORCING FOR UPWARD VERTICAL MOTION WILL CONTRIBUTE TO TORNADO POTENTIAL FARTHER NORTH...INTO SOUTHERN PORTIONS OF THE GREAT LAKES REGION. DAMAGING WINDS/LARGE HAIL WILL ALSO LIKELY ACCOMPANY SQUALL LINE LATE THIS AFTERNOON AND EARLY EVENING AS IT PROGRESSES INTO/THROUGH THE LOWER OHIO VALLEY. SURGING ARCTIC FRONT IS EXPECTED TO HAVE A GREATER TENDENCY TO UNDERCUT SQUALL LINE BY THE MID/LATE EVENING HOURS. THIS WILL CONTRIBUTE TO A DIMINISHING SEVERE THREAT...AND MAY OCCUR FAIRLY RAPIDLY DURING THE 17/03-06Z TIME FRAME. AS MID/UPPER RIDGING BUILDS INTO THE SOUTH CENTRAL STATES...STRONGER MID/UPPER FORCING WILL CONTINUE RAPIDLY EASTWARD AHEAD OF SHORT WAVE TROUGH INTO THE LOWER GREAT LAKES REGION OVERNIGHT. AS THIS BECOMES INCREASING CUT-OFF FROM GULF MOISTURE...THUNDERSTORM ACTIVITY WILL DIMINISH. ...LIKELY BY 12Z FRIDAY. ..KERR.. 02/16/2006 ...NOTICE... THE STATION RELATIVE POINTS IN THIS PRODUCT WERE DISCONTINUED ON 14 FEBRUARY 2006 AND ARE NOW AVAILABLE IN THE FOLLOWING PRODUCTS: WMO HEADER: AWIPS ID: WUUS01 PTSDY1 WUUS02 PTSDY2 WUUS03 PTSDY3 A SERVICE CHANGE NOTICE ...SCN05-39... PROVIDES DETAILS ON THIS TRANSITION. FOR ADDITIONAL DETAILS SEE THE FOLLOWING WEB ADDRESS USING LOWER CASE LETTERS: WWW.NWS.NOAA.GOV/OM/NOTIF.HTM CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z |