SPC AC 160521
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1221 AM CDT MON MAY 16 2005
   
   VALID 171200Z - 181200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 55 NNE
   RAP 40 SSE MBG 25 NW HON 35 ENE YKN 35 ENE OLU 25 SW BIE 30 WNW HUT
   30 NNW GAG 25 SSW LBL 50 NW GCK 25 SE SNY 25 NW AIA 25 S RAP 55 NNE
   RAP.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 WNW INL 45 ENE MSP
   10 SE OTM 45 NE SZL 45 SSW END ABI 15 NNE SJT 35 SSE MAF 45 NE HOB
   30 W AMA 40 S LAA 15 NNE LHX PUB 30 NE ALS 50 E DRO 45 SSE 4BL 35 NW
   U17 50 SE EVW 35 SE RKS 35 N RKS 30 W COD 50 N BIL 55 ENE HVR.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SSW HUM 35 S BTR
   55 SE MEI 15 W ANB 40 NW AND 40 E HSS 25 SE RDU 45 ESE ECG.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CENTRAL
   AND NRN PLAINS...
   
   ...SYNOPSIS...
   MID-LEVEL PATTERN IS FORECAST TO DEAMPLIFY SOMEWHAT WITH TIME THIS
   PERIOD AS SHORT-WAVE TROUGH MOVES EWD OUT OF THE ROCKIES INTO THE
   MEAN RIDGE POSITION OVER THE PLAINS.
   
   AT THE SURFACE...MAIN FEATURE WILL BE A STRONG LOW / TROUGH OVER THE
   PLAINS...WHICH WILL SHIFT EWD WITH TIME IN CONJUNCTION WITH
   EWD-MOVING UPPER FEATURE.  
   
   ...CENTRAL / NRN PLAINS...
   STRONG SLY LOW-LEVEL FLOW IS FORECAST ACROSS THE PLAINS IN RESPONSE
   TO STRONG / ELONGATED AREA OF LOW PRESSURE MOVING EWD INTO THE
   PLAINS AHEAD OF UPPER TROUGH.  BOUNDARY LAYER MOISTURE RETURN WILL
   BE SOMEWHAT LIMITED ACROSS THIS REGION DUE TO SURFACE HIGH /
   RELATIVELY COOL AIRMASS ACROSS SRN PLAINS OVER THE PREVIOUS 24 TO 48
   HOURS. HOWEVER...UPPER 50S DEWPOINTS BENEATH PLUME OF STEEP
   MID-LEVEL LAPSE RATES SHIFTING SLOWLY EWD SHOULD ALLOW AIRMASS TO
   BECOME MODERATELY UNSTABLE BY AFTERNOON ACROSS THE WRN HALF OF THE
   PLAINS.  
   
   THUNDERSTORMS WILL LIKELY DEVELOP ACROSS THE CENTRAL HIGH PLAINS
   DURING THE AFTERNOON INVOF SURFACE TROUGH.  STRONGER CAP WITH SWD
   EXTENT...WEAKER INSTABILITY / SHEAR FURTHER N...AND PERSISTENT RIDGE
   OVER THE ERN HALF OF THE PLAINS THROUGH THE AFTERNOON SUGGESTS THAT
   THE MOST WIDESPREAD / PERSISTENT CONVECTION WILL LIKELY EXIST ACROSS
   WRN KS / NEB INTO THE SRN HALF OF SD.
   
   THOUGH LOW-LEVEL FLOW SHOULD BE VERY STRONG FROM THE S...A
   COMPARATIVELY MODEST / COMPACT SSWLY 45 KT JET STREAK IS FORECAST 
   TO SHIFT EWD INTO THE REGION DURING THE AFTERNOON / EVENING.  AS A
   RESULT...SOMEWHAT LIMITED DEEP-LAYER SHEAR AND GENERALLY
   UNIDIRECTIONAL DEEP-LAYER WIND FIELD IS EXPECTED ACROSS A LARGE
   PORTION OF THE AREA.  
   
   NONETHELESS...DEGREE OF INSTABILITY / SHEAR SHOULD SUPPORT
   SUPERCELLS...WITH PRIMARY THREAT BEING LARGE HAIL.  WIND FIELD WOULD
   ALSO SUPPORT A DAMAGING WIND THREAT -- PARTICULARLY IF SMALL-SCALE
   LINEAR ORGANIZATION COULD EVOLVE.
   
   THOUGH STORMS SHOULD CONTINUE / SHIFT EWD THROUGH MUCH OF THE NIGHT
   -- AIDED BY STRONG LOW-LEVEL JET...SEVERE THREAT SHOULD DIMINISH
   SLOWLY THROUGH THE EVENING / OVERNIGHT.
   
   ...SERN U.S. / FL PENINSULA...
   MODELS SUGGEST ONGOING CONVECTION INVOF WEAK SURFACE BOUNDARY
   LINGERING ACROSS PARTS OF THE CAROLINAS / GA AT THE START OF THE
   PERIOD.  DEPENDING UPON DEGREE OF RESULTING CONVECTIVE CONTAMINATION
   OF THE AIRMASS...AND UPON AMOUNT OF SUBSEQUENT DIURNAL
   BOUNDARY-LAYER HEATING...CONVECTION MAY REDEVELOP / INTENSIFY DURING
   THE AFTERNOON. WEAK LOW-LEVEL WINDS BUT SLIGHTLY STRONGER FLOW
   ALOFT MAY SUPPORT A COUPLE OF MORE ORGANIZED STORMS...AND PERHAPS A
   LOW-END / LOCAL SEVERE THREAT. 
   
   FURTHER S ACROSS FL...MOIST / DESTABILIZING BOUNDARY LAYER SHOULD
   FUEL AFTERNOON CONVECTION INVOF SEA-BREEZE BOUNDARIES -- WITH MOST
   NUMEROUS STORMS ANTICIPATED ATTM ACROSS THE WRN HALF OF THE
   PENINSULA.  THOUGH INSTABILITY WILL NOT BE PARTICULARLY
   STRONG...SOMEWHAT ENHANCED MID / UPPER FLOW ON NRN PERIPHERY OF
   SUB-TROPICAL JET MAY ALLOW A FEW STRONGER / MORE ORGANIZED STORMS
   AND LOCAL / LIMITED SEVERE THREAT.
   
   ..GOSS.. 05/16/2005
   
   ...NOTICE...
   THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
   SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
   WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
   IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
   CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
   WILL PROVIDE DETAILS ON THE TRANSITION.
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z