Mar 1, 2007 0600 UTC Day 1 Convective Outlook
Updated: Thu Mar 1 08:36:17 UTC 2007
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Public Severe Weather Outlook

The SPC is forecasting.   Please read the latest public statement about this event.

Categorical Graphic
20070301 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20070301 1200 UTC Day 1 Tornado Probabilities Graphic
Probabilistic Damaging Wind Graphic
20070301 1200 UTC Day 1 Damaging Wind Probabilities Graphic
Probabilistic Large Hail Graphic
20070301 1200 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 010613
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1213 AM CST THU MAR 01 2007
   
   VALID 011200Z - 021200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS PARTS OF ERN
   MISSISSIPPI AND ALABAMA...WHERE POTENTIAL EXISTS FOR AN OUTBREAK OF
   TORNADOES...SOME POSSIBLY STRONG OR VIOLENT....
   
   ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK
   AREA...ACROSS MUCH OF THE LOWER HALF OF THE MISSISSIPPI VALLEY AND
   GULF/SOUTH ATLANTIC COAST STATES....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS TODAY/TONIGHT ACROSS A LARGE
   PORTION OF THE CENTRAL/EASTERN STATES....
   
   LARGE SCALE PATTERN ACROSS THE U.S. DURING THIS FORECAST PERIOD WILL
   BECOME DOMINATED BY A DEEP CYCLONE NOW DEVELOPING ACROSS THE CENTRAL
   PLAINS...IN RESPONSE TO AN INTENSE MID/UPPER JET STREAK NOSING
   NORTHEAST OF THE SOUTHERN ROCKIES.  UPPER JET CORE IS PROGGED TO
   SHIFT THROUGH THE SOUTHERN PLAINS/NORTHERN GULF STATES AND SOUTHERN
   APPALACHIANS TODAY THROUGH EARLY FRIDAY...WITH SURFACE CYCLONE
   GRADUALLY OCCLUDING AS IT LIFTS THROUGH THE UPPER MISSISSIPPI
   VALLEY/UPPER GREAT LAKES REGION.  AS THIS OCCURS...A COLD FRONT WILL
   SURGE EAST OF THE MISSISSIPPI VALLEY...LIKELY REACHING ATLANTIC
   COASTAL AREAS BY 12Z FRIDAY.  AND...MODELS SUGGEST SECONDARY SURFACE
   CYCLOGENESIS MAY OCCUR FROM THE  LEE OF THE NORTH CENTRAL
   APPALACHIANS INTO NORTHERN MID ATLANTIC COASTAL AREAS.
   
   ALTHOUGH GULF RETURN FLOW MAY NOT BECOME OF SUFFICIENT QUALITY TO
   SUPPORT WIDESPREAD SIGNIFICANT DESTABILIZATION ACROSS THE CENTRAL
   AND EASTERN STATES...IT SHOULD BE ADEQUATE ENOUGH TO SUPPORT AN
   EXTENSIVE CONVECTIVE OUTBREAK...GIVEN FAVORABLE LARGE SCALE FORCING
   FOR UPWARD VERTICAL MOTION.  STRONG WIND FIELDS/SHEAR WILL SUPPORT
   SEVERE POTENTIAL ACROSS A BROAD AREA...INCLUDING A RISK OF STRONG
   TORNADOES AND STRONG STRAIGHT LINE DAMAGING WINDS... PARTICULARLY
   ACROSS PARTS OF THE GULF INTO SOUTH ATLANTIC COAST STATES.
   
   ...PARTS OF THE CNTRL GULF STATES/TENNESSEE VALLEY...
   WHILE STRONGER MID-LEVEL FORCING SHIFTS NORTHEAST OF THE LOWER
   MISSOURI/MIDDLE MISSISSIPPI VALLEY DURING THE MIDDAY AND AFTERNOON
   HOURS...LARGE-SCALE ASCENT IS EXPECTED TO WEAKEN CAP SUFFICIENTLY
   FOR MORE SCATTERED CONVECTIVE DEVELOPMENT EAST OF THE LOWER
   MISSISSIPPI VALLEY.  THIS MAY COMMENCE AS EARLY AS THE 15-18Z TIME
   FRAME ACROSS PARTS OF WESTERN TENNESSEE/MISSISSIPPI...BEFORE
   SPREADING ACROSS ALABAMA DURING THE PEAK AFTERNOON HEATING HOURS. 
   WITH BOUNDARY LAYER DEW POINTS CLIMBING THROUGH THE MID 60S
   CONTRIBUTING TO MIXED LAYER CAPE OF 500 TO 1000 J/KG...SUPERCELLS
   ROOTED NEAR THE SURFACE WILL BY ACCOMPANIED BY A RELATIVELY HIGH
   RISK OF TORNADOES.  LARGE...CLOCKWISE CURVED HODOGRAPHS BENEATH A
   STRONG UPPER JET WILL BE SUPPORTIVE OF A FEW LONG-LIVED/LONG TRACK
   SUPERCELLS WITH STRONG OR VIOLENT TORNADOES.
   
   ...MIDDLE MISSISSIPPI/LOWER OHIO VALLEY/MID ATLANTIC COAST...
   EVOLUTION OF SQUALL LINE IS EXPECTED EARLY IN THE PERIOD ALONG/
   AHEAD OF SURFACE FRONT IN RESPONSE TO STRONG FORCING.  FORCING WILL
   COMPENSATE FOR ANTICIPATED WEAK INSTABILITY...AND DAMAGING WINDS
   COULD BECOME WIDESPREAD AS ACTIVITY SURGES EASTWARD.  STRONG
   LOW-LEVEL SHEAR WILL SUPPORT A RISK FOR ISOLATED TORNADOES...
   PARTICULARLY EARLY TODAY FROM PARTS OF EASTERN MISSOURI INTO
   INDIANA.  COOLER/DRIER BOUNDARY LAYER FARTHER EASTWARD INTO THE OHIO
   VALLEY SEEMS LESS FAVORABLE FOR TORNADOES...BUT A DAMAGING WIND
   THREAT IS EXPECTED TO CONTINUE THROUGH THE APPALACHIANS... AND
   POSSIBLY NORTHERN MID ATLANTIC COASTAL AREAS BY 12Z FRIDAY.
   
   ...SOUTHERN MID ATLANTIC COASTAL AREAS...
   BOUNDARY LAYER IS EXPECTED TO RECOVER NORTHWARD THROUGH THE
   CAROLINAS BETTER THAN FARTHER NORTHWARD ALONG THE ATLANTIC SEABOARD.
    AND...THIS SEEMS TO SUPPORT A MORE CERTAIN SEVERE THREAT LATE THIS
   EVENING/OVERNIGHT.  WITH A 60 TO 80 KT SOUTHERLY LOW-LEVEL JET
   PROGGED TO EVOLVE TO THE LEE OF THE APPALACHIANS... DAMAGING WINDS
   APPEAR LIKELY TO BE PRIMARY SEVERE THREAT WITH PRE-FRONTAL
   CONVECTIVE LINE/LINES.  THOUGH LOW-LEVEL WIND PROFILES ARE EXPECTED
   TO BE LARGELY UNIDIRECTIONAL...LOW-LEVEL SHEAR WILL STILL BE EXTREME
   AND FAVORABLE FOR AT LEAST AN ISOLATED TORNADO THREAT.
   
   ...CENTRAL FLORIDA PENINSULA...
   LOW-LEVEL FLOW/SHEAR IS ONLY EXPECTED TO BE WEAK TO MODERATE IN
   STRENGTH...BUT DEEP LAYER SHEAR SHOULD BE MORE THAN SUFFICIENT FOR
   ISOLATED SUPERCELLS.  WEAK CAPPING SHOULD ALLOW FAIRLY WIDESPREAD
   CONVECTIVE DEVELOPMENT AS MOIST BOUNDARY LAYER WARMS WITH
   INSOLATION.
   
   ..KERR.. 03/01/2007
   
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