May 22, 2013 0100 UTC Day 1 Convective Outlook
Updated: Wed May 22 01:03:40 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the southern plains and arklatex this afternoon and tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

Categorical Graphic
20130522 0100 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130522 0100 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
20130522 0100 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
20130522 0100 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.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 120,367 9,616,469 Shreveport, LA...Jackson, MS...Clarksville, TN...Albany, NY...College Station, TX...
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 120,367 9,616,469 Shreveport, LA...Jackson, MS...Clarksville, TN...Albany, NY...College Station, TX...
   SPC AC 220059
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0759 PM CDT TUE MAY 21 2013
   
   VALID 220100Z - 221200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE TN
   VALLEY...LOWER MS VALLEY AND SRN PLAINS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN
   NY...VT...NH AND MA...
   
   ...TN VALLEY/LOWER MS VALLEY/SRN PLAINS...
   SEVERAL LINEAR MESOSCALE CONVECTIVE SYSTEMS ARE ONGOING FROM WRN TN
   SWWD ACROSS NW MS INTO NW LA AND EAST TX. THE STORMS ARE LOCATED ON
   THE NWRN EDGE OF A CORRIDOR OF MODERATE INSTABILITY. MLCAPE VALUES
   ACROSS THE WARM SECTOR ARE ESTIMATED IN THE 2000 TO 3000 J/KG RANGE
   FROM THE SRN PLAINS ENEWD INTO THE LOWER MS VALLEY. THIS ALONG WITH
   LARGE-SCALE ASCENT ASSOCIATED WITH AN UPPER-LEVEL TROUGH IN THE SRN
   PLAINS WILL CONTINUE TO SUPPORT MCS DEVELOPMENT THIS EVENING. IN
   ADDITION...A 50 TO 65 KT MID-LEVEL JET IS ANALYZED OVER THE ERN
   PARTS OF THE SRN PLAINS. THIS FEATURE IS CREATING MODERATE DEEP
   LAYER SHEAR PROFILES ACROSS MUCH OF THE WARM SECTOR WHICH WILL HELP
   TO MAINTAIN A SEVERE THREAT THROUGH THE MID EVENING. REGIONAL
   WSR-88D VWPS ACROSS THE WARM SECTOR SHOW UNIDIRECTIONAL WINDS IN THE
   BOUNDARY LAYER WITH ABOUT 20 TO 30 KT OF FLOW. THIS COINCIDING WITH
   0-3 KM LAPSE RATES OF 7.0 TO 7.5 C/KM SHOULD BE FAVORABLE FOR
   DAMAGING WIND GUSTS WITH THE MORE ORGANIZED BOWING LINE SEGMENTS. AN
   ISOLATED THREAT FOR HAIL AND A BRIEF TORNADO WILL BE POSSIBLE WITH
   ROTATING CELLS ELEMENTS. HOWEVER...THE LOW-LEVEL WIND PROFILES
   APPEAR MOST FAVORABLE FOR DAMAGING WIND GUSTS.
   
   ....NRN APPALACHIAN MTNS...
   THE LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL RIDGE IN PLACE
   ACROSS THE APPALACHIAN MTNS WITH A DISTURBANCE MOVING EWD ACROSS THE
   TOP OF THE RIDGE INTO NY AND NEW ENGLAND. THIS FEATURE IS SUPPORTING
   AN ARCHING LINE OF THUNDERSTORMS EXTENDING SWWD ACROSS NERN...CNTRL
   AND SRN NY. MLCAPE VALUES AHEAD OF THE LINE ARE ESTIMATED TO BE IN
   THE 500 TO 1500 J/KG RANGE. THIS COMBINED WITH MODERATE TO STRONG
   DEEP LAYER SHEAR PROFILES WILL HELP SUPPORT THE LINE FOR SEVERAL
   MORE HOURS THIS EVENING. THE ALBANY NY WSR-88D VWP SHOWS DIRECTIONAL
   TURNING BELOW 2 KM AGL WITH 25 TO 30 KT OF FLOW IN THE LOW TO
   MID-LEVELS. THE LOW-LEVEL WIND APPEARS FAVORABLE FOR WIND DAMAGE AS
   A BOWING LINE SEGMENT MOVES EWD ACROSS ERN NY...VT...NH AND MA OVER
   THE NEXT FEW HOURS. HAIL WILL ALSO BE POSSIBLE WITH THE MORE INTENSE
   CELLS.
   
   ..BROYLES.. 05/22/2013
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z