[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 201245
SWODY1
SPC AC 201243

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0743 AM CDT FRI MAY 20 2005

VALID 201300Z - 211200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM RRT
BJI AXN BKX MHE 9V9 RAP 81V GCC SHR BIL 3HT 10 N LWT 70 NE LWT 25
NNW MOT 75 NNW DVL.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 E
JAX 25 W CTY ...CONT... 30 S GPT 40 ESE MCB 20 S HEZ MLU 40 W GLH 20
ESE JBR 20 S PAH 20 E CKV 60 SSE TYS 45 WNW CAE 30 S FLO 40 SSW CRE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 E ELO MSP FOD 25 S
OLU 25 SE MCK 20 NNE AKO 15 NE RWL 65 NW ENV 4LW 4BK.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 ENE GLS 40 SSW LFK
25 SW GGG 25 N TXK 45 NNE LIT 40 SW EVV 55 ESE LUK AOO ACY.

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SERN 
STATES...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN HI PLNS
AND THE NRN PLNS...

...SYNOPSIS...
DOMINANT SWRN STATES RIDGE WILL EXPAND SOMEWHAT NWD AND EWD INTO THE
CNTRL AND SRN PLNS THIS PERIOD AS COMPACT SHORTWAVE IMPULSE NOW NEAR
EVV CONTINUES SSE TO NEAR SAV. FARTHER W...SHORTWAVE TROUGH NOW
NEARING THE NRN CA/SRN ORE CST EXPECTED TO SWEEP ENE INTO THE NRN
GRT BASIN LATER TODAY BEFORE CONTINUING ACROSS THE NRN HI PLNS ON
SATURDAY.

AT LWR LEVELS...APPROACH OF GRT BASIN SYSTEM WILL BE ACCOMPANIED BY
STRENGTHENING LEE CYCLONE OVER THE NRN HI PLNS TODAY.  THE LOW AND
ITS ATTENDANT COLD FRONT SHOULD REACH CENTRAL ND BY 12Z SATURDAY.  A
WARM FRONT WILL DEVELOP LATER IN THE PERIOD OVER THE NRN
PLNS...EXTENDING GENERALLY SSE FROM THE ND LOW.  OVER THE
SOUTHEAST...SURFACE PATTERN WILL BE DOMINATED BY COMPOSITE OUTFLOW
BOUNDARY LEFT FROM OVERNIGHT STORMS.  BY MID MORNING...THE BOUNDARY
SHOULD EXTEND IN A BROKEN ARC FROM NE NC TO SE GA.  ANOTHER SEGMENT
SHOULD REACH FROM NE GA INTO NRN AL.  THESE BOUNDARIES WILL FOCUS
RENEWED STORM DEVELOPMENT LATER TODAY.

...LWR TN VLY SSE TO MIDDLE/ERN GULF CST...
COMBINATION OF SURFACE HEATING AND CONSIDERABLE LARGE SCALE ASCENT
PROVIDED BY APPROACHING UPPER DISTURBANCE WILL DESTABILIZE REGION
ALONG AND S OF AFOREMENTIONED OUTFLOW BOUNDARY OVER PARTS OF
TN/MS/AL AND GA.  WLY LOW TO MID TROPOSPHERIC FLOW S OF BOUNDARY
WILL CONTINUE TO ADVECT MOISTURE INTO REGION...AND WILL MAINTAIN
FAIRLY STEEP LAPSE RATES /AROUND 7.5 - 8.0 DEG C PER KM/ AT MID
LEVELS.  AS A RESULT...AFTERNOON MLCAPE SHOULD EXCEED 2000 J/KG.  AT
THE SAME TIME...INCREASING NNWLY UPPER LEVEL FLOW WILL STRENGTHEN
SHEAR AND CREATE A SUBSTANTIAL DIRECTIONAL COMPONENT TO WIND
PROFILES.  THUS...ENVIRONMENT SHOULD SUPPORT SUPERCELLS.

PRESENCE OF THE OUTFLOW BOUNDARY AND THE LIKELIHOOD THAT THE FEATURE
WILL CONTINUE MOVING SSE SUGGEST THAT AT LEAST SOME OF TODAY'S
CONVECTION WILL QUICKLY ASSUME A LINEAR MODE.  NEVERTHELESS...GIVEN
DEGREE OF INSTABILITY AND SHEAR...POTENTIAL WILL EXIST FOR EMBEDDED
SUPERCELLS.  ASSOCIATED LEWPS AND BOWING SEGMENTS WILL YIELD LARGE
HAIL/HIGH WIND.  AT THE SAME TIME... REGION AHEAD OF CONVECTIVE BAND
LIKELY WILL BE ONLY WEAKLY CAPPED.  THUS EXPECT DEVELOPMENT OF
SCATTERED ACTIVITY S AND E OF MAIN CONVECTIVE BAND.  WHILE THESE
LATTER STORMS WILL ALSO ORGANIZE INTO LINES...SOME MAY REMAIN
DISCRETE LONG ENOUGH TO POSE A THREAT FOR TORNADOES IN ADDITION TO
HAIL/WIND.

WITH TIME...ALL OF THE STORMS SHOULD CONSOLIDATE INTO A LARGE
SSE-MOVING MCS.  THIS SYSTEM MAY BACKBUILD SOMEWHAT W INTO SRN MS/SE
LA THIS EVENING/TONIGHT AS ERN PORTION MOVES INTO THE NERN GULF OF
MEXICO.

...ATL SEABOARD FROM NE SC TO SE VA...
DESTABILIZATION LIKELY WILL BE LIMITED ALONG THAT PORTION OF THE
ATLANTIC COAST N OF ABOUT MYR IN WAKE OF ESE-MOVING OUTFLOW BOUNDARY
NOW CROSSING THE COASTAL PLN.  WITH LOW TO MID LEVEL SHEAR EXPECTED
TO REMAIN FAIRLY WEAK...ANY SEVERE THREAT SHOULD REMAIN ISOLATED.

...NRN HI PLNS/NRN PLNS...
ISOLATED TO WIDELY SCATTERED TSTMS WILL FORM WITH SURFACE HEATING
OVER THE HIGHER TERRAIN OF S CNTRL AND SE MT.  OTHER STORMS MAY
DEVELOP A BIT LATER EWD ALONG DEVELOPING WARM FRONT INTO WRN ND AND
PERHAPS NW SD. SHEAR PROFILES WILL BE VERY FAVORABLE FOR
SUPERCELLS...WITH INCREASING SELY LOW LEVEL WINDS VEERING TO 40+ KT
WSWLY FLOW AT MID LEVELS.

BOUNDARY LAYER MOISTURE WILL BE SOMEWHAT LIMITED...WITH MEAN SURFACE
DEWPOINTS LIKELY TO RANGE FROM AROUND 50 IN S CNTRL MT TO AROUND 60
INVOF DEVELOPING WARM FRONT IN ND/NRN SD.  BUT GIVEN  PRESENCE OF
STEEP LOW TO MID LEVEL LAPSE RATES...AFTERNOON MLCAPE SHOULD AVERAGE
BETWEEN 1000 AND 1500 J/KG...AND COULD LOCALLY EXCEED 2000 J/KG. 
THUS...A THREAT WILL EXIST FOR BOTH LARGE HAIL AND HIGH WIND WITH
ANY SUSTAINED STORMS THAT DO FORM.  INCREASINGLY BACKED LOW LEVEL
FLOW N OF DEEPENING LEE CYCLONE COULD ALSO POSE A THREAT FOR
TORNADOES IN SE MT.

PERSISTENT FORCING PROVIDED BY BOTH DCVA WITH GRT BASIN SHORTWAVE
IMPULSE...AND ASSOCIATED WARM ADVECTION IN THE NRN PLNS...SHOULD
SUPPORT UPSCALE DEVELOPMENT INTO A STRONG TO SEVERE MCS OVER ND
TONIGHT.  THIS SYSTEM MAY PRODUCE POCKETS OF SIGNIFICANT WIND DAMAGE
AS LLJ STRENGTHENS AND FOSTERS FORWARD PROPAGATION.

..CORFIDI/TAYLOR.. 05/20/2005

...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.