[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 110549
SWODY1
SPC AC 110546

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1246 AM CDT TUE MAY 11 2004

VALID 111200Z - 121200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 NE
ELO 20 NNE MKT 40 SSW SPW 15 ESE OLU 55 N RSL 25 NE CDS 65 SSW CDS
40 SSE LBB 35 W LBB 45 NW GLD 30 S AIA 25 NNW RAP 15 S DIK 60 NNE
MOT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 SSE MRF 10 SSE HOB
CAO 20 S AKO 15 NNW DEN GUC 20 N CEZ 30 SE CDC 30 NW TPH 40 W U31
OWY 20 NNE MQM 55 N GGW ...CONT... 20 SW WAL 25 W RIC 45 WNW GSO 35
ESE AND 25 W JAX 10 SSW PIE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SW ART 10 S HUL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 NW SZL 30 W JLN 15
NW FSM 55 SW ARG 40 NNE DYR 10 WSW PAH 25 E BLV 30 NW SZL.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN PLAINS INTO THE TX
PNHDL...

...SYNOPSIS...
DEEP MID-LEVEL TROUGH WILL BE MAINTAINED ACROSS THE INTERMOUNTAIN W
THROUGH THE DAY 1 PERIOD WITH DOWNSTREAM HEIGHT RISES FROM THE GREAT
LAKES EWD INTO THE NERN STATES. MORE SPECIFICALLY...VORTICITY MAX
AND ASSOCIATED 90KT UPPER-LEVEL JET STREAK /CURRENTLY OVER SRN NV/
WILL EJECT NEWD INTO THE CNTRL HIGH PLAINS THIS EVENING WITH
RESULTANT 30-60M HEIGHT FALLS OVERSPREADING THE DAKOTAS/NEB.

AT THE SURFACE...INTENSE CYCLONE INITIALLY OVER NERN WY WILL RAPIDLY
DEVELOP ENEWD ACROSS NRN SD AND INTO NRN MN OVERNIGHT WITH SECONDARY
CYCLOGENESIS FORECAST ALONG COLD FRONT OVER WRN NEB BY LATE
AFTERNOON OR EARLY EVENING. ATTENDANT COLD FRONT WILL SWEEP SEWD AND
SHOULD EXTEND FROM CNTRL ND SWWD THROUGH CNTRL SD INTO WRN NEB AT
THIS TIME. FARTHER S...LEE TROUGH/DRYLINE WILL BECOME ESTABLISHED
FROM DEEPENING NEB LOW SWD ACROSS WRN KS INTO WRN TX. IN THE
E...WEAK COLD FRONT WILL SETTLE SWD TODAY...LIKELY EXTENDING FROM
SRN NEW ENGLAND WWD INTO THE MIDDLE OH VALLEY BY MID AFTERNOON.

...NRN PLAINS SWD INTO WRN TX...
CLUSTERS OF TSTMS WILL LIKELY BE ONGOING INITIALLY ACROSS PORTIONS
OF THE DAKOTAS INTO NEB ALONG AXIS OF 50-60KT LLJ. A FEW OF THE MOST
INTENSE STORMS MAY PRODUCE ISOLATED LARGE HAIL THROUGH THE MORNING
HOURS PRIOR TO SHIFTING NEWD INTO MN. DEGREE OF RESIDUAL
CLOUDINESS/CONVECTIVELY PROCESSED AIR LEFT OVER FROM THE MORNING
CONVECTION UNCERTAIN AT THIS TIME...AND THIS COULD HAVE A NEGATIVE
IMPACT ON DESTABILIZATION PROCESS ACROSS THE WARM SECTOR LATER
TODAY. CURRENT THINKING IS THAT AN AXIS OF MODERATE INSTABILITY WILL
DEVELOP BY AFTERNOON FROM CNTRL NEB NWD INTO CNTRL/ERN SD WITH
MLCAPES APPROACHING 1500-2500 J/KG. DEEP MIXING AND SUSTAINED
CONVERGENCE WITHIN FRONTAL ZONE SHOULD BE SUFFICIENT TO OVERCOME CAP
AND INITIATE TSTMS BY LATE AFTERNOON OR EARLY EVENING FROM THE CNTRL
DAKOTAS SWWD INTO WRN NEB.

STRENGTHENING SWLY MID-LEVEL FLOW TO 45-55KTS ACROSS THE FRONTAL
ZONE WILL SUPPORT SUPERCELL STRUCTURES INITIALLY WITH LARGE HAIL AND
POSSIBLY AN ISOLATED TORNADO OR TWO. HOWEVER...NEARLY PARALLEL
ORIENTATION OF DEEP SHEAR VECTOR TO BOUNDARY SUGGESTS A FAIRLY RAPID
TRANSITION INTO A CONVECTIVE LINE WITH DAMAGING WINDS TONIGHT ACROSS
THE ERN DAKOTAS/NERN NEB INTO WRN MN.

FARTHER S ACROSS WRN KS INTO WRN TX...HEIGHT FALLS ON SRN PERIPHERY
OF EVOLVING UPPER TROUGH WILL SPREAD EWD ACROSS DRYLINE/LEE TROUGH.
THIS COUPLED WITH MODERATELY UNSTABLE AIRMASS /CHARACTERIZED BY
MLCAPES OF 1000-2000 J/KG/ SHOULD SUPPORT ISOLATED TO SCATTERED TSTM
DEVELOPMENT. RELATIVELY WEAK DEEP-LAYER SHEAR SHOULD LIMIT OVERALL
SEVERE THREAT...HOWEVER ISOLATED STRONG WINDS/LARGE HAIL WILL BE
POSSIBLE WITH THE STRONGEST STORMS.

...SRN NEW ENGLAND/DELMARVA REGION WWD INTO THE OH/TN VALLEYS...
DEWPOINTS IN THE 60S AND DAYTIME HEATING WILL ONCE AGAIN CONTRIBUTE
TO POCKETS OF MODERATE INSTABILITY THIS AFTERNOON WITH MLCAPES
APPROACHING 1000-2000 J/KG. RELATIVELY WEAK CAP OBSERVED ON FORECAST
SOUNDINGS SHOULD ALLOW NUMEROUS TSTM CLUSTERS TO DEVELOP...THE
GREATEST CONCENTRATION OF WHICH SHOULD BE ALONG SAGGING COLD FRONT.
ISOLATED DAMAGING WIND/LARGE HAIL OCCURRENCES WILL BE POSSIBLE WITH
THE MOST INTENSE UPDRAFTS INTO THE EARLY EVENING HOURS. A GRADUAL
DEMISE IS EXPECTED THEREAFTER WITH THE LOSS OF DAYTIME HEATING.

..MEAD/CROSBIE.. 05/11/2004

...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.