[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 211258
SWODY1
SPC AC 211255

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0755 AM CDT FRI MAY 21 2004

VALID 211300Z - 221200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 N
HSE 15 ENE RWI 15 ENE DAN 35 E CRW 45 W UNI 40 WSW DAY 25 N HUF 25 N
SPI OTM 20 N FNB 20 SE RSL 30 S DDC 45 WNW GAG 40 SSW LBL EHA 55 NE
LAA 40 ENE AKO 30 W SNY DGW 40 SW GCC 40 ENE SHR 30 SE MLS 65 NNW
REJ 30 SSE Y22 30 S ABR 45 E ATY 20 S EAU 35 NW OSH MBL 60 N MTC
...CONT... 35 NNW JHW 40 E BFD CXY DOV 20 NE WAL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 W MSS BID
...CONT... 10 NE JAX 25 S CTY ...CONT... 30 SSW HUM 50 SW CBM DYR 45
W STL 35 NNE COU 35 NNE SZL 30 NE EMP ICT 35 S END 35 ENE ABI 30 SE
DRT ...CONT... 60 W MRF 25 E CNM DHT LAA LIC DEN 25 NE EGE 25 NW GJT
U28 50 NNE BCE 25 SSW P38 65 NNE NID 40 ENE MER 35 N UKI 40 NE 4BK
40 NW RDM 20 SE OLM 25 NE UIL ...CONT... 70 NW ISN 40 SSE DVL 15 SE
CMX.

...THERE IS A SLGT RISK OF SVR TSTMS NRN-CENTRAL HIGH PLAINS TO
TIDEWATER ATLANTIC COAST...

...SYNOPSIS...
UPPER AIR PATTERN THIS PERIOD WILL FEATURE WRN CONUS MEAN
TROUGH...AND ZONALLY ORIENTED RIDGING OVER MOST OF GULF COAST. LONG
FETCH OF GRADUALLY ANTICYLONICALLY CURVING FLOW WILL EXTEND
DOWNSTREAM FROM WRN TROUGH -- WITH 250 MB JET AXIS ROUGHLY FROM 4
CORNERS TO BLACK HILLS THEN ACROSS NRN GREAT LAKES TO ERN QUE. 
WEAK/LOW-AMPLITUDE SHORTWAVE PERTURBATIONS MAY TRAVEL IN THIS FLOW
STREAM AFTER EJECTING FROM BASE OF WRN TROUGH. ONE OF THESE
FEATURES -- PRESENTLY OVER IA AND CONTRIBUTING TO SEVERE/ELEVATED
CONVECTION NEAR MS RIVER -- IS EXPECTED TO CROSS LOWER MI BY MID-DAY
AND REACH UPSTATE NY EARLY THIS EVENING.  MVC ASSOCIATED WITH
ONGOING PA/WV MCS SHOULD MOVE SEWD ACROSS DELMARVA REGION BEFORE
APPROXIMATELY 21Z.

AT SFC...WAVY FRONTAL ZONE IS ANALYZED FROM E-CENTRAL CO AND NWRN KS
NEWD THROUGH LOW OVER SERN NEB...EWD ACROSS IA/NRN IL/NRN
INDIANA/NWRN OH.  FRONTAL SEGMENT FROM ERN NEB TO INDIANA SHOULD
LIFT NWD THROUGH TODAY AS WARM FRONT...BUT WITH SOME DELAY OVER
WI/IL/LM AREA BECAUSE OF OUTFLOW EFFECTS FROM ONGOING MS VALLEY MCS.
 FRONT BECOMES MORE DIFFUSE EWD ACROSS PA/NJ.  FRONT ALSO SHOULD
LIFT NWD ACROSS CENTRAL PLAINS TODAY -- AMIDST BROAD ZONE OF LOW
LEVEL SLYS AND E OF DEEPENING LEE TROUGH.  TROUGH SHOULD EXTEND FROM
ERN CO NWD ACROSS BLACK HILLS REGION AND INTO SRN ND BY 22/00Z.

...OH TO MID ATLANTIC/TIDEWATER REGION...
ONGOING MCS MAY PRODUCE GUSTS BELOW 50 KT SEVERE CRITERIA - BUT
STILL CAPABLE OF OCCASIONAL DAMAGE -- AS ACTIVITY MOVES SEWD THIS
MORNING ACROSS BLUE RIDGE AND PIEDMONT TOWARD TIDEWATER.  STORMS
SHOULD FORWARD-PROPAGATE INTO ENVIRONMENT CHARACTERIZED BY NEARLY
UNIDIRECTIONAL WNW FLOW AND INCREASING SBCAPE.

FRONTAL ZONE E OF APPALACHIANS SHOULD BE EFFECTIVELY SHUNTED SWD FOR
MUCH OF PERIOD BY OUTFLOW BOUNDARY PRODUCED BY MCS NOW CROSSING
WV/PA APPALACHIANS...THOUGH LATE MORNING AND AFTERNOON INSOLATION
WILL LEAD TO PROGRESSIVE EWD DESTABILIZATION OF WRN PORTION OF
OUTFLOW POOL ON OH/PA/WV. ADDITIONAL DEVELOPMENT IS POSSIBLE LATE
MORNING INTO AFTERNOON IN ARC FROM COASTAL PLAIN AHEAD OF
MVC...AROUND OUTFLOW EDGE AND NWWD INTO OH.  SEPARATE CONVECTION IS
POSSIBLE SWD ACROSS ERN VA IN ENVIRONMENT OF WEAK VERTICAL
SHEAR...BUT ALSO...RICH BOUNDARY LAYER MOISTURE AND SMALL AFTERNOON
CINH WITH MLCAPE UP TO NEAR 3000 J/KG. MAIN MODE S OF FRONT SHOULD
BE MULTICELLULAR WITH AN ABUNDANCE OF MARGINAL WIND/HAIL EVENTS
POSSIBLE. A FEW SUPERCELLS AND ORGANIZED BOW/LEWP MODES WILL BE
POSSIBLE NEAR FRONTAL/OUTFLOW BOUNDARY...WITH DAMAGING GUSTS AND
ISOLATED LARGE HAIL.

...UPPER MS VALLEY...SRN GREAT LAKES AREA...
ONGOING MCS IS EXPECTED TO MOVE ESEWD ACROSS SRN WI/NRN IL/LM REGION
 THIS MORNING WITH HAIL AND STRONG-SEVERE GUSTS POSSIBLE.  SRN
PORTION OF REMNANTS OF THIS COMPLEX MAY ACQUIRE SFC-BASED INFLOW AND
STRENGTHEN LATE THIS MORNING INTO AFTERNOON -- ESPECIALLY IF IT
BACKBUILDS MUCH -- AS FOREGOING WARM FRONT LIFTS NWD AND WARM SECTOR
BECOMES MORE STRONGLY HEATED DIABATICALLY.  MODIFIED RAOBS AND RUC
FCST SOUNDINGS SUGGEST 70S SFC DEW POINTS WILL CONTRIBUTE TO MLCAPE
2000-3000 J/KG IN ENVIRONMENT OF AROUND 30-40 KT DEEP-LAYER SHEAR S
OF FRONT.  DAMAGING WIND IS EXPECTED WITH ANY ORGANIZED COMPLEX THAT
MAY CROSS THIS REGION TODAY.

BEST SUPERCELL POTENTIAL AND GREATEST TORNADO PROBABILITIES SHOULD E
INVOF WARM FRONT -- AND AWAY FROM LARGE CONVECTIVE CLUSTERS -- WHERE
SHEAR/LIFT/VORTICITY ARE MAXIMIZED.  MODIFIED MODEL SOUNDINGS OVER
NRN IL AND MI/INDIANA BORDER REGION BY 21Z SHOW LARGE 0-3 KM AGL
HODOGRAPHS WITH 250-400 J/KG 0-3 KM SRH...AND 45-55 KT 0-6 KM SHEAR.


...N-CENTRAL PLAINS...
STRONG HEATING AND RICH BOUNDARY LAYER MOISTURE WILL CONTRIBUTE TO
EXTREMELY UNSTABLE CONDITIONS BY MID/LATE AFTERNOON OVER PORTIONS
NRN KS...SRN/ERN NEB...ERN SD AND IA...WITH MLCAPES 2500-4000 J/KG. 
BACKED BOUNDARY LAYER FLOW NEAR AND N OF FRONT...AND E OF SFC ROUGH
-- WILL CONTRIBUTE TO FAVORABLE VERTICAL SHEAR FOR SUPERCELLS. ANY
DIURNAL STORMS THAT CAN BREAK CAP WOULD BECOME SEVERE QUICKLY...WITH
BOTH SUPERCELL AND BOW ECHO MODES POSSIBLE.  DAMAGING HAIL AND
SEVERE GUSTS ARE POSSIBLE...WITH TORNADO POTENTIAL STRONGLY TIED TO
STORM-SCALE AND MESOSCALE BOUNDARY INTERACTIONS YET TO BECOME
APPARENT.  FARTHER W OVER HIGH PLAINS AND BLACK HILLS...STRONG
HEATING OF HIGHER TERRAIN -- AMIDST INCREASING LOW LEVEL MOISTURE --
SHOULD SUPPORT SEVERE TSTMS THIS AFTERNOON AND EVENING...ALSO
INCLUDING SUPERCELLS.  ANOTHER MCS SHOULD EVOLVE FROM
AFTERNOON/EVENING ACTIVITY AND MOVE GENERALLY EWD TOWARD MID/UPPER
MS VALLEY...PRODUCING STRONG-SEVERE GUSTS AND HAIL.

...CENTRAL/SRN HIGH PLAINS...
ISOLATED TO WIDELY SCATTERED TSTMS POSSIBLE LATE AFTERNOON INTO MID
EVENING -- INITIATING INVOF DRYLINE AS INTENSE HEATING LOCALLY
ERODES CINH...THEN MOVING EWD 50-100 NM BEFORE DISSIPATING. 
ACTIVITY WILL BE RELATIVELY HIGH-BASED ATOP DEEPLY MIXED BOUNDARY
LAYERS.  POTENTIAL EXISTS FOR A FEW SEVERE GUSTS AND HAIL EVENTS. 
EXPECT COVERAGE TO DECREASE SWD FROM WRN KS ACROSS W TX...EXCEPT
FROM PERMIAN BASIN SWD WHERE HEATING OF  HIGHER TERRAIN AND LIFT
FROM RESIDUAL BOUNDARIES MAY CONCENTRATE CONVECTION.

..EDWARDS.. 05/21/2004

...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.