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 150553
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1253 AM CDT SUN MAY 15 2011
   
   VALID 151200Z - 161200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID ATLANTIC
   STATES/DELMARVA...
   
   ...SYNOPSIS...
   A BLOCKED LONGWAVE PATTERN WILL CONTINUE TO PREVAIL OVER NORTH
   AMERICA TODAY...WITH DUAL UPPER TROUGHS FLANKING A HIGHLY AMPLIFIED
   RIDGE OVER THE CENTRAL CONUS/CANADA. A SLOW MOVING STACKED/CLOSED
   LOW OVER THE OH VALLEY IS EXPECTED TO GRADUALLY OPEN THROUGH
   TONIGHT...WHILE A JET STREAK/SECONDARY SHORTWAVE TROUGH SPREADING
   SOUTHEASTWARD ACROSS THE MO VALLEY/LOWER MS VALLEY ACTS TO REINFORCE
   THE SOUTHERN PORTION OF THE EASTERN STATES UPPER TROUGH. WITHIN THE
   WESTERN STATES BROAD TROUGH...A SHORTWAVE PORTION OF THIS TROUGH IS
   EXPECTED TO PIVOT NORTHEASTWARD OVER THE WESTERN GREAT
   BASIN/NORTHERN INTERMOUNTAIN WEST THROUGH TONIGHT.
   
   ...MID-ATLANTIC STATES/UPPER OH VALLEY/NC...
   ISOLATED TO SCATTERED SHOWERS/TSTMS WILL CONTINUE TO OCCUR AHEAD OF
   A SLOW EASTWARD MOVING COLD FRONT ADVANCING FROM NEAR THE
   APPALACHIANS EARLY TODAY TO THE MID-ATLANTIC/SOUTH ATLANTIC COASTS
   BY THIS EVENING. AS THE AFOREMENTIONED UPPER LOW OPENS/SLOWLY
   SPREADS EASTWARD...A WEAK SURFACE LOW WILL DEVELOP
   EAST-NORTHEASTWARD ACROSS THE DELMARVA/EASTERN PA THROUGH THIS
   AFTERNOON AS A WARM FRONT SHIFTS NORTHWARD ALONG THE ATLANTIC
   SEABOARD. 
   
   WHILE NEGLIGIBLE CAPPING MAY LEAD TO A RELATIVELY EARLY UPSWING IN
   DIURNAL CONVECTION...POCKETS OF STRONGER HEATING SHOULD ALLOW FOR
   WEAK TO PERHAPS MODERATE DESTABILIZATION THIS AFTERNOON FROM
   VA/NORTHERN NC TO THE DELMARVA VICINITY. AS A MODERATE SPEED MAX
   SHIFTS EAST-NORTHEASTWARD ON THE SOUTHERN PERIPHERY OF THE OH VALLEY
   UPPER LOW THIS AFTERNOON...GRADUALLY STRENGTHENING FLOW ALOFT MAY
   FURTHER CONTRIBUTE TO SOME ORGANIZED/SUSTAINED MULTICELLS. WHILE A
   WIDESPREAD SEVERE RISK IS NOT EXPECTED...THE STRONGEST STORMS WILL
   BE CAPABLE OF ISOLATED DAMAGING WINDS AND/OR MARGINALLY SEVERE HAIL
   THIS AFTERNOON. ADDITIONALLY...A FEW FUNNELS/PERHAPS A BRIEF TORNADO
   CANNOT BE RULED OUT ACROSS CENTRAL/SOUTHERN PA AND PERHAPS EASTERN
   OH IF SUFFICIENT AFTERNOON DESTABILIZATION OCCURS ATTENDANT TO THE
   UPPER LOW AND ADJACENT WEST-EAST SURFACE BOUNDARY.
   
   ...FL PENINSULA...
   SCATTERED SHOWERS/TSTMS WILL REMAIN POSSIBLE ALONG/AHEAD OF A COLD
   FRONT SPREADING SOUTHEASTWARD ACROSS THE FL PENINSULA TODAY...WITH
   TSTMS ESPECIALLY FOCUSED ALONG THE EAST COAST SEA BREEZE THIS
   AFTERNOON. WITH MODERATE DIURNAL DESTABILIZATION WITHIN A MODESTLY
   SHEARED ENVIRONMENT...THE STRONGER TSTMS MAY PRODUCE DOWNBURSTS
   AND/OR MARGINALLY SEVERE HAIL THROUGH THIS AFTERNOON.
   
   ...NORTHERN INTERMOUNTAIN WEST...
   A PORTION OF THE WESTERN STATES TROUGH IS EXPECTED TO PIVOT
   NORTHEASTWARD OVER THE NORTHERN INTERMOUNTAIN WEST TODAY. SOME
   UNCERTAINTY EXISTS REGARDING THE DEGREE OF DESTABILIZATION
   TOWARD/AROUND PEAK HEATING AHEAD OF AN ADVANCING COLD
   FRONT...HOWEVER STRONG/DEEP SOUTHERLY FLOW WOULD SUPPORT SOME
   SUSTAINED STRONG/SEVERE TSTMS CAPABLE OF STRONG WINDS AND HAIL
   SHOULD AT LEAST MODEST DESTABILIZATION OCCUR.
   
   ..GUYER/SMITH.. 05/15/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z