SPC AC 210528
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1128 PM CST SUN MAR 20 2005
   
   VALID 211200Z - 221200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 ESE
   LFK 50 NE CLL 65 E ACT 45 ENE DAL 15 N DUA 40 WSW MLC 25 N MLC 10
   SSW MKO 15 WNW FSM 30 NW HOT 35 W PBF 40 S PBF 35 ENE MLU ESF 15 WNW
   POE 20 ESE LFK.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 SW
   PSX 35 SSW AUS ACT 50 N FTW 30 NNE FSI 40 ESE GAG 20 SSE P28 35 ENE
   PNC 20 W HRO 60 ENE LIT 25 SW UOX 45 SSW CBM 35 E MEI 60 SSW SEM 10
   SE PNS.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 ENE CRP 35 S SAT
   50 ENE JCT 35 SSW SPS 30 SSW CDS 25 SE LAA 30 WNW HLC 20 NW OJC HOP
   GAD 55 E MCN 30 ENE SAV.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 N ACV 30 SSW RBL
   25 WNW SAC 20 NNW MRY.
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SERN OK...NERN/ECNTRL
   TX...SWRN AR AND NWRN/NCNTRL LA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SRN
   PLAINS TO THE LOWER MS VLY...
   
   ...SYNOPSIS...
   A STRONG MIDLEVEL SHORTWAVE TROUGH AND ASSOCIATED 60-70 KT H5 JET
   WILL TRANSLATE EWD ACROSS THE CNTRL AND SRN PLAINS ON MONDAY. 
   SURFACE LOW OVER THE CNTRL HIGH PLAINS WILL DEVELOP ESEWD ALONG A
   WARM FRONT INTO NWRN OK BY 18Z...CNTRL OK BY 00Z AND THEN REMAIN IN
   PLACE THROUGH 12Z TUE. THE WARM FRONT WILL MOVE NEWD INTO ECNTRL
   OK...CNTRL AR AND SRN MS DURING THE DAY MON WHILE A DRYLINE MIXES
   EWD THROUGH SRN OK AND ERN TX. 
   
   ...SRN PLAINS TO THE LWR MS VLY...
   A POTENTIALLY ACTIVE SEVERE WEATHER EVENT COULD UNFOLD MONDAY
   AFTERNOON AND NIGHT.  MORNING ELEVATED TSTMS ARCING FROM ERN KS INTO
   ERN OK AND NERN TX WILL MOVE NEWD INTO THE OZARKS AND MID MS VLY
   EARLY MONDAY.  SO FAR...NAM/NAMKF HAVE SEEMINGLY BEEN OVERDONE ON
   THE COVERAGE OF THIS CONVECTION.  IF THIS REMAINS THE
   CASE...CLOUDS/PCPN MAY NOT BE AS WIDESPREAD AND THE WARM SECTOR
   COULD EXPAND RATHER FAR N AND E.
   
   THE BOUNDARY LAYER WILL CONTINUE TO MOISTEN AHEAD OF THE TRIPLE
   POINT/APPROACHING UPPER WAVE.  BY AFTERNOON...SURFACE DEW POINTS AOA
   55F SHOULD BE COMMON AS FAR N AS CNTRL OK AND THE ARKLATEX TO THE
   LOWER 60S ACROSS ERN TX.  THOUGH THIS MOISTURE IS OF A MODIFIED
   POLAR VARIETY...VERY STEEP MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO
   MLCAPES OF 1000-2000 J/KG.  
   
   AS STRONG LARGE SCALE ASCENT SPREADS EWD...FIRST INITIATION SHOULD
   OCCUR VCNTY THE SURFACE LOW/DRYLINE ACROSS NCNTRL/CNTRL OK RATHER
   EARLY MONDAY AFTERNOON WHERE MID-LEVEL TEMPERATURES WILL BE COOLER. 
   THIS ACTIVITY WILL THEN DEVELOP SWD ALONG THE DRYLINE AND EWD ALONG
   THE WARM FRONT INTO ERN/SERN OK AND ECNTRL TX BY MID- AFTERNOON. 
   
   0-6KM VERTICAL SHEAR OF 45-50 KTS WILL BE MORE THAN SUFFICIENT FOR
   SUPERCELLS...PARTICULARLY ACROSS THE MDT RISK AREA.  DISCRETE CELLS
   WILL BE POSSIBLE EARLY IN THE LIFE CYCLES OF THE STORMS. 
   COMBINATION OF THE SHEAR AND THE MAGNITUDE OF LAPSE RATES WILL MAKE
   FOR EFFICIENT HAIL PRODUCTION AND A FEW VERY LARGE HAILSTONES CAN BE
   EXPECTED WITH THE SUPERCELLS.  
   
   BACKED SELY BOUNDARY LAYER FLOW BENEATH A 50 KT SLY H85 JET WILL
   ENHANCE THE LOW-LEVEL HELICITY...PRIMARILY IN A CORRIDOR FROM SERN
   OK/NERN TX ACROSS THE ARKLATEX INTO NRN LA.  0-1KM SRH VALUES COULD
   EXCEED 250 M2/S2 AND A FEW TORNADOES WILL BE POSSIBLE. ANOTHER MORE
   ISOLD TORNADO POTENTIAL WILL EXIST VCNTY THE SURFACE LOW/COLD CORE
   ALOFT OVER CNTRL OK WHERE BACKED LOW LEVEL FLOW WILL EXIST.  VERY
   LARGE HAIL WILL ALSO BE POSSIBLE...EVEN WITH THE WEAKER VERTICAL
   SHEAR EXPECTED.
   
   OVERNIGHT MONDAY...TSTMS WILL BUILD SWD INTO ERN TX AND PROBABLY
   CONGEAL INTO LINE SEGMENTS WITH EMBEDDED SUPERCELLS.  UNCERTAINTY
   EXISTS ON HOW FAR S THE ACTIVITY WILL BUILD...BUT A COUPLE 21Z SREF
   MEMBERS BUILD STORMS ALL THE WAY TO THE UPPER TX COAST.  ALL FACETS
   OF SEVERE WEATHER WILL BE POSSIBLE MONDAY NIGHT...INCLUDING LARGE
   HAIL...DAMAGING WINDS AND ISOLD TORNADOES AS THE STORMS MOVE EWD
   TOWARD THE LWR MS VLY. ACTIVITY MAY REACH THE MS RVR...OR DEVELOP
   FARTHER E ALONG THE WARM FRONT ACROSS CNTRL/SRN MS VERY LATE AT
   NIGHT.
   
   ...CNTRL/SRN FL...
   IF HIGH/MID-LEVEL CLOUD CANOPY CAN DISSOLVE OVER CNTRL/SRN FL BY
   MONDAY AFTERNOON...AIR MASS SHOULD BECOME UNSTABLE AS BOUNDARY LAYER
   MOISTENS AND HEATS.  A FEW TSTMS COULD DEVELOP ALONG THE WARM FRONT
   AMIDST 45-50 KTS OF DEEP LAYER SHEAR.  UNCERTAINTY EXISTS ON THE
   STRENGTH OF LARGE SCALE FORCING.  WILL OPT TO ADD A CONDITIONAL
   THREAT FOR AN ISOLD DAMAGING WIND GUST OR HAIL AS CONFIDENCE IS NOT
   TERRIBLY HIGH ATTM.
   
   ..RACY/CROSBIE.. 03/21/2005
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z