[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 110541
SWODY1
SPC AC 110539

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1239 AM CDT SUN JUL 11 2004

VALID 111200Z - 121200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 60 NNW
CMX 45 NW IWD 60 S DLH 15 WNW LSE 40 WSW CID 40 N STJ 35 SSW BIE 50
ENE HLC 35 SSW IML 10 SE SNY 45 NE AIA 35 ENE RAP 35 W REJ 10 W 4BQ
45 NE COD 45 ESE LVM 20 ENE LVM 20 NNE LWT 70 NW GGW.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 NNW ANJ 65 NE ESC
50 ESE ESC 15 ENE TVC 15 NE MBS 85 NE MTC ...CONT... 15 WNW ART 25
ESE UCA 40 NW EWR 15 E NEL ...CONT... 35 NW DRT 35 E SJT 45 SE SPS
40 SE OKC 15 NNE OKC 25 NE CDS 40 SSW LBB 20 SSE INK 40 WSW MRF
...CONT... 40 SE YUM 50 E BLH 20 SE PRC 30 ENE INW 55 SSW 4BL 35 SW
GJT 45 W CAG 35 E RWL 40 ESE RIW 25 NNE BPI 20 N TWF 50 SSW S80 25 N
MSO 30 S FCA 30 NNW 63S.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SSE AUG 25 NW BML.

...THERE IS A SLGT RISK OF SVR TSTMS FROM MT EWD ACROSS THE NRN AND
CENTRAL PLAINS INTO THE UPPER GREAT LAKES / OH VALLEY...

...SYNOPSIS...
LARGE MEAN UPPER RIDGE AND ASSOCIATED WEAK FLOW WILL PERSIST ACROSS
THE S CENTRAL AND SERN CONUS THIS PERIOD...WHILE BELT OF STRONGER
UPPER FLOW EXTENDS IN AN ANTICYCLONIC ARC FROM CA / THE GREAT BASIN
INTO THE NRN PLAINS AND THEN EWD ACROSS THE GREAT LAKES / SRN CANADA
INTO NEW ENGLAND.  A WEAKER BRANCH OF THIS FASTER FLOW IS FORECAST
TO SHIFT FROM THE MIDDLE MO VALLEY EWD ACROSS THE MID MS / LOWER AND
MIDDLE OH VALLEYS THROUGH THE PERIOD AS SHORT-WAVE TROUGH -- NOW
CROSSING THE NRN PLAINS -- MOVES EWD ACROSS THE UPPER GREAT LAKES.

STRONGEST FEATURE EMBEDDED IN THE MAIN BELT OF FASTER FLOW -- LIKELY
TO BE ASSOCIATED WITH A MORE SIGNIFICANT SEVERE WEATHER EPISODE --
IS NOW EVIDENT OVER WA.  ALTHOUGH THIS FEATURE WILL SHIFT NEWD INTO
THE CANADIAN PRAIRIE WITH STRONG RIDGE PREVAILING ACROSS THE NRN
PLAINS...SRN EXTENSION OF THIS TROUGH SHOULD MOVE EWD THROUGH THE
MEAN RIDGE AXIS ACROSS MT AND INTO THE NRN PLAINS DURING THE
AFTERNOON / EVENING.

IN RESPONSE...LOW OVER SERN MT SHOULD DEEPEN / MOVE SLOWLY ESEWD
WITH TIME...REACHING THE WRN DAKOTAS BY 12/00Z AND THEN APPROACHING
THE MO VALLEY BY THE END OF THE PERIOD.  THIS LOW AND ASSOCIATED
WEAK FRONTS / TROUGHS SHOULD BE THE FOCUS FOR SEVERE THUNDERSTORM
DEVELOPMENT THIS AFTERNOON AND TONIGHT.

...ERN MT / ND...
SELY LOW-LEVEL FLOW IS FORECAST ACROSS ERN MT EARLY IN THE PERIOD N
OF WEAK SURFACE LOW / AHEAD OF APPROACHING SHORT-WAVE TROUGH. 
DAYTIME HEATING SHOULD ALLOW AIRMASS TO BECOME MODERATELY UNSTABLE
/2000 TO 3000 J/KG MEAN-LAYER CAPE/ BY AFTERNOON...WITH STORMS
EXPECTED TO DEVELOP ALONG CONVERGENCE AXIS OVER ERN MT.  

WITH 40 TO 50 KT WSWLY MID-LEVEL JET SPREADING EWD ACROSS MT DURING
THE AFTERNOON...DEEP-LAYER SHEAR WILL SUPPORT SUPERCELL DEVELOPMENT.
 LARGE HAIL AND DAMAGING WINDS CAN BE EXPECTED...WHILE SOMEWHAT
LIMITED LOW-LEVEL MOISTURE SHOULD LIMIT THE TORNADO POTENTIAL.

STORMS ARE EXPECTED TO SHIFT EWD INTO WRN ND DURING THE AFTERNOON /
EARLY EVENING. GREATER LOW-LEVEL MOISTURE ACROSS THIS REGION ALONG
WITH INCREASING SELY LOW-LEVEL FLOW SUGGESTS A GREATER POTENTIAL FOR
ISOLATED TORNADOES ALONG WITH A CONTINUED LARGE HAIL / DAMAGING WIND
THREAT.  LATE EVENING / OVERNIGHT STORM MODE IS UNCERTAIN
ATTM...ALTHOUGH LATEST ETA WOULD SUGGEST AN MCS MOVING RAPIDLY EWD
ACROSS ND.  ASSUMING THIS SCENARIO...A MORE WIDESPREAD THREAT FOR
DAMAGING WINDS WOULD LIKELY EVOLVE...THOUGH FAIRLY STRONG / VEERING
LOW- TO MID-LEVEL FLOW WOULD ALSO SUPPORT SUPERCELL / TORNADO THREAT
WITH MORE ISOLATED CELLS.

...CENTRAL HIGH PLAINS...
ISOLATED LATE AFTERNOON THUNDERSTORMS ARE FORECAST TO DEVELOP ACROSS
THE HIGH PLAINS FROM SWRN SD SWWD INTO ERN CO...S OF MORE WIDESPREAD
STORMS OVER THE NRN PLAINS BUT ASSOCIATED WITH SRN FRINGES OF THE
SAME UPPER SHORT-WAVE TROUGH.  ALTHOUGH RELATIVELY DRY AND CAPPED
BOUNDARY LAYER SHOULD LIMIT CONVECTIVE COVERAGE...DAYTIME HEATING
COUPLED WITH EITHER WEAK UPSLOPE FLOW OR CONVERGENCE NEAR LEE TROUGH
SHOULD BE SUFFICIENT WITHIN MARGINALLY-UNSTABLE AIRMASS TO ALLOW
ISOLATED STORM DEVELOPMENT.

ALTHOUGH MID-LEVEL FLOW IS EXPECTED TO WEAKEN WITH SWD EXTENT...NLY
COMPONENT ALOFT ABOVE SLY LOW-LEVEL FLOW SHOULD PROVIDE SUFFICIENT
SHEAR FOR AT LEAST MULTICELL SEVERE STORMS AS FAR S AS NERN CO. 
LARGE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE PRIMARY THREATS
WITH THESE STORMS...WHICH MAY CONTINUE MOVING SLOWLY EWD INTO THE
PLAINS THROUGH THE EVENING / OVERNIGHT AS WARM ADVECTION INCREASES
WITH NOCTURNAL LOW-LEVEL JET DEVELOPMENT.

...MIDDLE MO VALLEY EWD INTO THE UPPER GREAT LAKES / OH VALLEY...
THUNDERSTORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD
ACROSS PARTS OF THE REGION AS INITIAL UPPER TROUGH WITHIN WLY FLOW N
OF UPPER RIDGE SHIFTS EWD TOWARD THE GREAT LAKES REGION.

ALTHOUGH INSTABILITY -- AND THUS SEVERE THREAT -- IS FORECAST TO
REMAIN LIMITED EAST OF THE MS RIVER...DAYTIME HEATING SHOULD ALLOW
AIRMASS TO BECOME MODERATELY UNSTABLE ACROSS ERN NEB / THE ERN
DAKOTAS AND INTO IA / WRN MN.  THIS SHOULD ALLOW LINGERING
CONVECTION TO INTENSIFY...ALONG WITH THE POTENTIAL FOR ISOLATED NEW
STORM DEVELOPMENT INVOF WEAK / CONVECTIVE BOUNDARIES.  ALTHOUGH
STORM ORGANIZATION SHOULD IN GENERAL BE LIMITED AS MARGINAL SHEAR IS
ANTICIPATED ACROSS THIS REGION...A FEW STRONGER MULTICELL CLUSTERS
WILL NONETHELESS BE CAPABLE OF PRODUCING LOCALLY DAMAGING WINDS /
HAIL THROUGH EVENING.

..GOSS.. 07/11/2004

...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.