Jul 26, 2011 0600 UTC Day 1 Convective Outlook
Updated: Tue Jul 26 06:18:05 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110726 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110726 1200 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
20110726 1200 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
20110726 1200 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 260614
   
   DAY 1 CONVECTIVE OUTLOOK RESENT 1
   NWS STORM PREDICTION CENTER NORMAN OK
   0114 AM CDT TUE JUL 26 2011
   
   VALID 261200Z - 271200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ND AND SD...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN
   PLAINS...CNTRL PLAINS AND UPPER MS VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NY AND NEW
   ENGLAND...
   
   CORRECTED FOR TYPO LAST PARAGRAPH
   
   ...NRN PLAINS/UPPER MS VALLEY...
   AN UPPER-LEVEL RIDGE OVER THE NRN PLAINS THIS MORNING WILL MOVE EWD
   INTO THE UPPER MS VALLEY BY THIS AFTERNOON. A WELL-DEFINED SFC LOW
   SHOULD EXIST ACROSS WRN SD THIS MORNING WITH ELEVATED THUNDERSTORMS
   ONGOING NORTH OF THE LOW ACROSS WRN ND. THIS CONVECTION IS FORECAST
   TO MOVE EWD INTO NCNTRL ND BY MIDDAY WITH NEW SFC-BASED CONVECTION
   INITIATING ACROSS SCNTRL ND AND NCNTRL SD BY MID-AFTERNOON AND
   MOVING ESEWD INTO THE MODERATE RISK AREA LATE THIS AFTERNOON.
   FORECAST SOUNDINGS ACROSS THE MODERATE RISK AREA AT 21Z SHOW AN
   IMPRESSIVE ENVIRONMENT WITH MLCAPE VALUES OF 2500 TO 3500
   J/KG....0-6 KM SHEAR IN THE 45 TO 55 KT RANGE AND CURVED LOW-LEVEL
   HODOGRAPHS. THIS ENVIRONMENT SHOULD BE FAVORABLE FOR SUPERCELLS AND
   THE STORMS SHOULD TEND TO REMAIN DISCRETE FOR AWHILE EVEN IF
   NUMEROUS STORMS INITIATE.
   
   THE CURRENT THINKING IS THAT SUPERCELLS WILL RAPIDLY DEVELOP THIS
   AFTERNOON IN SCNTRL ND ONCE SFC-BASED CONVECTION INITIATES. THESE
   STORMS SHOULD INITIALLY HAVE A THREAT FOR LARGE HAIL MOVING ESEWD
   INTO THE MODERATE RISK AREA. MID-LEVEL LAPSE RATES ON FORECAST
   SOUNDINGS SHOULD BE VERY STEEP EXCEEDING 8.0 C/KM ACROSS MUCH OF THE
   MODERATE RISK AREA SUGGESTING VERY LARGE HAIL WILL BE POSSIBLE WITH
   INTENSE DISCRETE SUPERCELLS. AS THE STORMS MATURE AND MOVE INTO THE
   LOW-LEVEL JET FORECAST TO BE LOCATED CENTERED JUST EAST OF THE
   MODERATE RISK AREA...LOW-LEVEL SHEAR PROFILES SHOULD BE FAVORABLE
   FOR TORNADOES AS WELL. A THREAT FOR STRONG TORNADOES MAY EXIST WITH
   SUPERCELLS THAT BECOME DOMINANT.
   
   ALTHOUGH UNCERTAINTY EXISTS CONCERNING STORM MODE TRANSITION...THE
   CURRENT THINKING IS THAT THE BROKEN LINE OF SUPERCELLS WILL
   GRADUALLY CONGEAL INTO A FAST-MOVING LINE MOVING ACROSS THE ERN
   DAKOTAS INTO WRN MN WHERE A THREAT FOR SIGNIFICANT WIND DAMAGE
   SHOULD EXIST. THIS MCS IS FORECAST TO MOVE AS FAR EAST AS
   MINNEAPOLIS MN DURING THE OVERNIGHT PERIOD WITH A THREAT FOR HAIL
   AND WIND DAMAGE.
   
   ...CNTRL HIGH PLAINS...
   WNWLY FLOW WILL BE IN PLACE ACROSS THE CNTRL HIGH PLAINS TODAY AS A
   SFC LOW MOVES EWD ACROSS SD. SOUTHWEST OF THE LOW...MODERATE
   INSTABILITY SHOULD DEVELOP FROM SD SWWD INTO WRN NEB AND NE CO TODAY
   WHERE A LINE OF THUNDERSTORMS IS FORECAST TO INITIATE LATE THIS
   AFTERNOON. FORECAST SOUNDINGS ALONG THE INSTABILITY AXIS AT 00Z SHOW
   MLCAPE VALUES FROM 1000 TO 2000 J/KG WITH 0-6 KM SHEAR IN THE 30 TO
   40 KT RANGE. THIS ENVIRONMENT ALONG WITH VERY STEEP MID-LEVEL LAPSE
   RATES OF 8.0 TO 8.5 C/KM SHOULD BE SUFFICIENT FOR SUPERCELL
   DEVELOPMENT WITH ISOLATED LARGE HAIL. HOWEVER...A CAPPING INVERSION
   IN PLACE FOR MUCH OF THE DAY ALONG WITH WARM AIR ALOFT MAY HINDER
   CONVECTIVE COVERAGE SOMEWHAT MAKING THE SEVERE THREAT MORE ISOLATED
   WITH SOUTHWEST EXTENT.
   
   ...NERN STATES...
   AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE INTO THE NERN STATES TODAY
   AS A WELL-DEFINED MID-LEVEL JET IN THE BASE OF THE TROUGH MOVES
   ACROSS THE REGION. MODEL FORECASTS ACROSS CNTRL NY AND WRN NEW
   ENGLAND DEVELOP A POCKET OF MODERATE INSTABILITY AROUND MIDDAY WHERE
   THUNDERSTORMS SHOULD INITIATE EARLY THIS AFTERNOON. FORECAST
   SOUNDINGS ACROSS THE SLIGHT RISK AREA AT 21Z SHOW MUCAPE VALUES
   AROUND 1000 J/KG WITH 50 KT OF DEEP LAYER SHEAR AND UNIDIRECTIONAL
   WIND PROFILES. THIS ALONG WITH STRONG FORCING ASSOCIATED WITH THE
   UPPER-LEVEL TROUGH SHOULD BE SUFFICIENT FOR A WIND DAMAGE THREAT AS
   A LINE OF STORMS DEVELOPS AND MOVES QUICKLY EWD INTO MAINE AND SRN
   NEW ENGLAND LATE THIS AFTERNOON.
   
   ...GULF COAST AND CAROLINAS...
   AN AXIS OF MODERATE TO STRONG INSTABILITY IS FORECAST TO DEVELOP
   THIS AFTERNOON FROM THE GULF COAST STATES NEWD INTO THE ERN
   CAROLINAS WHERE NUMEROUS THUNDERSTORM SHOULD INITIATE THIS
   AFTERNOON. FORECAST SOUNDING ALONG THIS CORRIDOR AT 21Z SHOW MLCAPE
   VALUES FROM 2000 TO 3000 J/KG...SFC DEWPOINTS IN THE MID 70S F AND
   STEEP LOW-LEVEL LAPSE RATES. THIS ENVIRONMENT SHOULD SUPPORT A
   MARGINAL THREAT FOR WIND DAMAGE WITH THE MORE INTENSE PULSE STORMS
   THIS AFTERNOON.
   
   ..BROYLES/COHEN.. 07/26/2011
   
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