Jun 1, 2012 1630 UTC Day 1 Convective Outlook
Updated: Fri Jun 1 16:34:28 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120601 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120601 1630 UTC Day 1 Tornado Probabilities 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
20120601 1630 UTC Day 1 Damaging Wind Probabilities 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
20120601 1630 UTC Day 1 Large Hail Probabilities 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 011630
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1130 AM CDT FRI JUN 01 2012
   
   VALID 011630Z - 021200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SRN PA...FAR ERN
   WV...MD AND NRN VA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER OH
   VALLEY...MID-ATLANTIC...CAROLINAS AND ERN GULF COAST STATES...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TX PANHANDLE AND
   NORTHWEST TX...
   
   ...MID-ATLANTIC/UPPER OH VALLEY/CAROLINAS...
   THE LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL TROUGH EXTENDING
   SWD ACROSS THE OH AND TN VALLEYS. THIS FEATURE WILL BECOME
   NEGATIVELY TILTED TODAY MOVING EWD INTO THE CNTRL APPALACHIAN MTNS.
   A BAND OF WELL-FOCUSED LARGE-SCALE ASCENT IS LOCATED TO THE EAST OF
   THE TROUGH WHICH IS PROVIDING SUPPORT FOR A LINE OF THUNDERSTORMS
   EXTENDING SWD FROM ERN OH INTO FAR ERN KY. THIS LINE WILL MOVE EWD
   INTO A WEAKLY UNSTABLE AIRMASS BUT WILL ALSO GAIN ACCESS TO
   INCREASING LOW-LEVEL MOISTURE AND SLIGHTLY STRONGER INSTABILITY THIS
   AFTERNOON. FOR THIS REASON...THE LINE IS EXPECTED TO SLOWLY RAMP UP
   IN INTENSITY WITH A WIND DAMAGE THREAT GRADUALLY DEVELOPING.
   
   FURTHER TO THE EAST ACROSS ERN NC...ERN VA AND MD...MESOANALYSIS
   CURRENTLY SHOWS A CORRIDOR OF MODERATE INSTABILITY WHERE MLCAPE IS
   ESTIMATED IN THE 1500 TO 2500 J/KG RANGE AND SFC DEWPOINTS ARE
   APPROACHING 70 F. THUNDERSTORMS ARE EXPECTED TO INITIATE ALONG THE
   INSTABILITY AXIS THIS AFTERNOON WITH STORMS SPREADING NEWD ACROSS
   THE MID-ATLANTIC LATE THIS AFTERNOON INTO EARLY THIS EVENING.
   FORECAST SOUNDINGS ACROSS THE WARM SECTOR LATE THIS AFTERNOON SHOW
   0-6 KM SHEAR VALUES IN THE 35 TO 40 KT RANGE WITH 0-3 KM STORM
   RELATIVE HELICITIES AROUND 250 M2/S2 SUGGESTING THE ENVIRONMENT WILL
   SUPPORT ROTATING STORMS AND TORNADOES. A TORNADO THREAT WILL LIKELY
   DEVELOP AS THE STORMS INTERACT WITH A WARM FRONT WHICH IS FORECAST
   TO BE FROM SCNTRL PA EXTENDING SSEWD ACROSS NRN VA AND MD AS THE
   LINE APPROACHES FROM THE WEST. THE TORNADO THREAT SHOULD INCREASE
   ACROSS PA AND MD AS THE STRONGEST BAND OF LARGE-SCALE ASCENT
   APPROACHES LATER THIS AFTERNOON. A COUPLING OF THE LOW AND MID-LEVEL
   JETS IS ALSO FORECAST TO OCCUR ACROSS NRN VA...MD AND PA WHICH MAY
   ALSO HELP TO ENHANCE THE QLCS TORNADO THREAT. HAVE ADDED A MODERATE
   RISK IN THE WASHINGTON DC METRO...BALTIMORE AREAS WHERE THE TORNADO
   THREAT IS EXPECTED TO BE THE GREATEST AND WHERE AN ISOLATED STRONG
   TORNADO CAN NOT BE RULED OUT. ANY ROTATING STORMS SHOULD ALSO BE
   CAPABLE OF PRODUCING WIND DAMAGE. AS THE STRONGER LARGE-SCALE ASCENT
   MOVES ACROSS THE MID-ATLANTIC EARLY THIS EVENING...A WELL-ORGANIZED
   LINEAR MCS IS EXPECTED TO BECOME THE DOMINANT CONVECTIVE FEATURE
   WITH AN ENHANCED WIND DAMAGE THREAT PRESENT ACROSS A LARGE AREA OF
   THE MID-ATLANTIC.
   
   FURTHER SOUTH ACROSS THE CAROLINAS...LARGE-SCALE ASCENT WILL BE
   WEAKER THAN IN AREAS TO THE NORTH. HOWEVER...MESOANALYSIS ALREADY
   SHOWS MODERATE INSTABILITY IN PLACE AND MODEL FORECASTS DO DEVELOP A
   LINE OF THUNDERSTORMS ALONG THE INSTABILITY AXIS THIS AFTERNOON.
   FORECAST SOUNDINGS LATE THIS AFTERNOON IN THE ERN CAROLINAS SHOW 0-6
   KM SHEAR OF 30 TO 35 KT SUGGESTING THE ENVIRONMENT WILL SUPPORT
   SEVERE STORMS. AS LOW-LEVEL LAPSE RATES BECOME STEEP THIS
   AFTERNOON...WIND DAMAGE WILL BE POSSIBLE WITH A LINE OF STORMS
   FORMING JUST AHEAD OF A COLD FRONT APPROACHING THE REGION FROM THE
   NORTHWEST.
   
   ...SRN GA/NRN FL...
   REMNANT MCV FROM OVERNIGHT CONVECTION IS SHEARING NEWD AT ROUGHLY
   25KT ACROSS SERN AL INTO SWRN GA.  IT APPEARS DIURNAL HEATING IS NOW
   CONTRIBUTING GREATLY TO THE RECENT INCREASE IN TSTM ACTIVITY ALONG
   LEADING EDGE OF DEBRIS CANOPY AND CONVECTIVE OUTFLOW. GIVEN THE
   MODEST DEEP LAYER SHEAR AND THE EXPECTED GRADUAL INCREASE IN
   CONVECTION AHEAD OF THIS FEATURE A SLIGHT RISK WILL BE ADDED TO THIS
   REGION TO ACCOUNT FOR ISOLATED DAMAGING WINDS AND PERHAPS SOME HAIL.
   CURRENT SPEED OF THIS FEATURE SUGGESTS THE BACK EDGE OF FORCING WITH
   MCV WILL PROGRESS INTO SERN GA BY 21Z.
   
   ...SWRN KS/TX AND OK PANHANDLES...
   NORTHWEST FLOW WILL BE IN PLACE ACROSS THE SRN PLAINS TODAY WITH
   SEVERAL SUBTLE IMPULSES MOVING SEWD ACROSS THE REGION. MESOANALYSIS
   ALREADY SHOWS AN AXIS OF MODERATE INSTABILITY IN PLACE ACROSS ERN
   NM. AS THE INSTABILITY AXIS SHIFTS EWD INTO WEST TX THIS
   AFTERNOON...STRONG INSTABILITY SHOULD DEVELOP AS THE CAPPING
   INVERSION WEAKENS. THIS SHOULD ALLOW FOR SCATTERED THUNDERSTORM
   DEVELOPMENT ACROSS THE TX PANHANDLE WITH THIS CONVECTION GRADUALLY
   MOVING SEWD INTO NORTHWEST TX EARLY THIS EVENING. FORECAST SOUNDINGS
   AT AMARILLO AT 02/00Z SHOW 0-6 KM SHEAR IN THE 40 TO 50 KT RANGE
   WITH MID-LEVEL LAPSE RATES APPROACHING 8.0 C/KM. THIS SHOULD SUPPORT
   A SUPERCELL AND LARGE HAIL THREAT. HOWEVER...LARGE TEMP-DEWPOINT
   SPREADS MAY ALSO HELP ENHANCE DOWNDRAFT SPEEDS SUGGESTING A WIND
   DAMAGE THREAT WILL ALSO EXIST ESPECIALLY IF THE STORMS CAN CONGEAL
   INTO A LINE EARLY THIS EVENING.
   
   ..BROYLES/CARBIN/COHEN/DARROW.. 06/01/2012
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z