[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 201628
SWODY1
SPC AC 201623

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1123 AM CDT MON SEP 20 2004

VALID 201630Z - 211200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SSE
SNY SNY 15 NE BFF 30 WNW PIR 15 NNE PIR 10 W 9V9 20 WNW BBW 20 SSE
LBF 30 ENE IML 30 SSE SNY.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 NW CTB 20 SE HLN
65 W MLS 45 NW REJ 30 NE Y22 55 NE MOT ...CONT... 55 ENE ELO 45 SSW
RSL 40 SSW LTS 65 SE MAF 45 NW DRT ...CONT... 55 SE ELP 45 SW CVS 40
E TAD 35 SSW LIC 25 NNW COS 15 SSE ASE 25 NE DRO 20 NNW FMN 30 ENE
U17 20 N SGU 35 SSW TPH 20 ESE RNO 25 ESE 4LW 35 NNE 63S.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 SSE LRD 20 WNW ALI
10 SSE VCT 20 ESE PSX.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 N PIE 40 SSE JAX.

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE
CENTRAL/NRN HIGH PLAINS...

...SYNOPSIS...
WRN TROUGH/ERN RIDGE WILL BE THE PRIMARY UPPER LEVEL FEATURES
THROUGH THE PERIOD. SEVERAL EMBEDDED SMALLER SHORTWAVES WILL ROTATE
NEWD ALONG THE ERN PERIPHERY OF THE WRN TROUGH AND AID CONVECTIVE
DEVELOPMENT OVER THE PLAINS STATES. IN PARTICULAR...ONE OF THESE
SHORTWAVES EVIDENT ON WV IMAGERY WILL ROTATE NEWD FROM WY/WRN CO
INTO THE SD/NEB BY THIS AFTERNOON. COMBINED WITH MODERATE
INSTABILITY AND STRONG CONVERGENCE ALONG THE FRONT...THIS FEATURE
WILL AID IN STRONG-SVR THUNDERSTORM DEVELOPMENT. STRENGTH OF SHEAR
COMBINED WITH OTHER PARAMETERS WILL AID IN A SLIGHT RISK OF SEVERE
THUNDERSTORMS FOR PORTIONS OF THE CNTRL/NRN HIGH PLAINS.  ADDITIONAL
STRONG TO ISOLATED SVR CONVECTIVE DEVELOPMENT SWD ALONG THE LEE
TROUGH/DRYLINE IS ALSO POSSIBLE...BUT OVERALL DECREASING WIND FIELDS
AND LAPSE RATES WILL LIMIT SEVERE THREAT IN THIS AREA.

...NEB/SD...
A SFC COLD FRONT LOCATED ALONG LINE FROM MBG SWWD TO NEAR CDR LATE
THIS MORNING WILL CONTINUE TO ADVANCE SEWD THROUGH THE AFTERNOON.
ALTHOUGH AREAS AHEAD OF THE FRONT HAVE SEEN SOMEWHAT RETARDED
DAYTIME HEATING SO FAR...RECENT TRENDS IN DIMINISHING CLOUD COVER 
SHOULD CONTINUE THROUGH THE EARLY AFTERNOON AS THE MID LEVEL DRYSLOT
CONTINUES TO PROGRESS NEWD INTO THE REGION. HOWEVER...MID LEVEL
LAPSE RATES ARE NOT LIKELY TO NOT IMPROVE GREATLY DUE TO THE
PRESENCE OF A MODERATELY STRONG MID LEVEL INVERSION EVIDENT ON THE
12Z DNR SOUNDING. WEAKER LAPSE RATES IN THE MID LEVELS WILL BE
OFFSET SOMEWHAT BY WELL ENTRENCHED LOW LEVEL MOISTURE /16 DEG C 850
MB DEWPT AT LBF THIS MORNING/...TO SUPPORT MUCAPES BETWEEN 1000-2000
J/KG BY MID AFTERNOON.

STRONG TO SVR CONVECTION IS ANTICIPATED TO DEVELOP FIRST ALONG THE
FRONT OVER SD IN THE 18-21Z TIME FRAME...WHERE MID LEVEL
FORCING/DYNAMICAL COOLING WITH EJECTING SHORTWAVE WILL BE GREATEST
AND LOW LEVEL CONVERGENCE IN THE VICINITY OF A SFC LOW WILL BE
MAXIMIZED. CONTINUED DAYTIME HEATING SWWD ALONG THE FRONTAL BOUNDARY
INTO WRN NB AND EVENTUALLY FAR NERN CO SHOULD AID IN ADDITIONAL
ISO-SCT SVR STORM DEVELOPMENT IN THESE AREAS BY LATE AFTERNOON.
WEAKER MID LEVEL WINDS AND GREATER MID LEVEL SUBSIDENCE SWD INTO
NWRN KS WILL LIMIT SVR COVERAGE INTO THIS AREA.

DESPITE SUFFICIENT DEEP LAYER SHEAR TO SUPPORT SUPERCELLS WITH LARGE
HAIL...INCREASING LOW LEVEL CONVERGENCE WITH SEWD MOVING FRONTAL
BOUNDARY DUE TO STRENGTHENING LOW LEVEL NLY FLOW IN THE WAKE OF THE
SHORTWAVE TROUGH PASSAGE...SUGGESTS THAT CONVECTION SHOULD QUICKLY
BECOME LINEAR ALONG THE FRONT WITH DAMAGING WINDS BECOMING A GREATER
THREAT WITH TIME. AS CONVECTION MOVES EWD TOWARDS ERN SD/CENTRAL NEB
DURING THE OVERNIGHT HOURS...WEAKENING MID LEVEL LAPSE RATES SHOULD
AID IN A DIMINISHING TREND IN THE SVR THREAT...DESPITE INCREASING
LOW LEVEL JET/CONVERGENCE.

...SRN HIGH PLAINS...
THERE IS SOME POTENTIAL FOR ISOLATED SVR STORMS TO DEVELOP SWD ALONG
THE LEE TROUGH/DRYLINE FROM NWRN KS/ECENTRAL CO INTO WRN TX
DURING THE LATE AFTERNOON. LARGE SCALE SUBSIDENCE WILL MAINTAIN WEAK
LAPSE RATES AROUND 6 DEG C/KM IN THE WAKE OF SHORTWAVE TROUGH
PRESENTLY MOVING ACROSS THE AREA. THIS WILL LIMIT INSTABILITY
/MLCAPES AROUND 1000 J/KG / AND STRONGER CONVECTIVE DEVELOPMENT...
DESPITE MODERATE LOW LEVEL CONVERGENCE AND SHEAR PROFILES.

...FL...
EARLY CONCERN FOR ISOLATED TORNADOES OVER FL APPEAR TO BE
DIMINISHING AS SYNOPTIC SCALE NLY FLOW AROUND LOW CENTER OFF THE
EAST COAST OF FL WILL LIMIT OVERALL POTENTIAL FOR ORGANIZED
SEABREEZE DEVELOPMENT.

..CROSBIE/EVANS.. 09/20/2004

...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.