[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 200601
SWODY1
SPC AC 200558

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1258 AM CDT SUN JUN 20 2004

VALID 201200Z - 211200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 SW
IRK 45 NW SGF 45 ENE TUL 40 SSE PNC 15 SE GAG 40 SSW EHA 40 S LAA 25
E LAR 40 NNW DGW 50 SW PHP 55 W YKN 20 SW OMA 35 NE STJ 40 SW IRK.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SSE DUG 70 ESE SOW
15 SSW LVS 25 SE TAD 10 SE PUB 25 NNW MTJ 20 SSW ELY 50 S BKE 25 ESE
PDX 35 ENE BLI ...CONT... 35 E MQT 40 N GRB 25 E MSN 15 NW MDH 40
WNW POF 45 ENE PBF 15 E UOX 30 WSW CSV 20 SSE 5I3 25 ESE PSK 15 SW
RDU HSE.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CENTRAL/SRN
PLAINS TO LOWER MO VALLEY...

...SYNOPSIS...
MODERATE ZONAL FLOW CURRENTLY EXTENDING FROM THE NORTH CENTRAL TO
NERN STATES WILL DEVELOP SWD ACROSS THE CENTRAL PLAINS TODAY AS A
STRONG UPPER TROUGH DROPS SSEWD ACROSS THE CENTRAL CANADIAN PRAIRIE
PROVINCES TO ONTARIO AND NRN PLAINS.  NEARLY CLOSED UPPER LOW
LOCATED OVER THE PAC NW WILL DEAMPLIFY AND SHEAR EWD ACROSS THE NRN
INTERMOUNTAIN WEST/NRN ROCKIES.

AT THE SURFACE...COLD FRONT ASSOCIATED WITH STRONG TROUGH OVER
CANADA IS EXPECTED TO EXTEND FROM A SURFACE LOW OVER WRN ONTARIO AT
00Z TO SRN ND AND ERN WY.  MEANWHILE...A SURFACE LOW WILL STRENGTHEN
ACROSS WRN/SWRN KS DURING THE DAY AHEAD OF THE UPSTREAM TROUGH...
BEFORE TRACKING EWD TONIGHT INTO CENTRAL/ERN KS.  E-W SURFACE
BOUNDARY...CURRENTLY LOCATED ACROSS CENTRAL TX IS PROGGED TO RETURN
NWD AS A WARM FRONT...REACHING OK/TX PANHANDLES TO ERN OK BY 00Z.

...CENTRAL/SRN PLAINS...
A CLUSTER OF STORMS MAY BE ONGOING ACROSS PORTIONS OF WRN/CENTRAL KS
AT THE START OF THE PERIOD...WITH AN OUTFLOW BOUNDARY FROM THIS
ACTIVITY EXTENDING MAINLY E-W ACROSS CENTRAL KS.  THIS ACTIVITY MAY
REINFORCE THE COOLER/STABLE BOUNDARY LAYER ACROSS NRN KS AND
NEB...LIMITING THE SEVERE THREAT OVER THESE AREAS UNTIL LATER IN THE
FORECAST PERIOD.  THE OUTFLOW BOUNDARY ALONG WITH THE RETURNING WARM
FRONT AND LEE TROUGH OVER THE CENTRAL HIGH PLAINS ARE EXPECTED TO BE
THE PRIMARY FOCI FOR CONVECTIVE INITIATION THIS AFTERNOON.

SLY LOW-LEVEL FLOW DEVELOPING IN RESPONSE TO THE DEEPENING SURFACE
LOW WILL ALLOW MOISTURE TO RETURN NWD...WITH LOWER 60S SURFACE
DEWPOINTS REACHING PORTIONS OF NEB BY MID AFTERNOON...AND AN AXIS OF
DEWPOINTS IN THE MID-UPPER 60S EXTENDING FROM WRN KS TO THE ERN TX
PANHANDLE.  STEEP MID-LEVEL LAPSE RATES SPREADING EWD ATOP THIS
LOW-LEVEL MOISTURE WILL RESULT IN MODERATE INSTABILITY FROM SERN
WY/ERN CO TO THE TX PANHANDLE AND EWD ACROSS WRN NEB TO CENTRAL KS
AND PORTIONS OF OK.

THUNDERSTORMS MAY RE-INTENSIFY OVER CENTRAL KS/SRN NEB BY EARLY
AFTERNOON FROM THE REMNANTS OF OVERNIGHT CONVECTION...WITH STORMS
BECOMING ROOTED AT THE SURFACE ALONG THE OUTFLOW BOUNDARY OVER
CENTRAL KS.  ADDITIONAL THUNDERSTORM DEVELOPMENT IS EXPECTED ALONG
THE WARM FRONT AND SURFACE LOW AND NWD ACROSS ERN CO/WRN KS TO SERN
WY/WRN NEB...WHERE SURFACE HEATING AND UPSLOPE FLOW WILL AID IN
CONVECTIVE INITIATION. INCREASING WLY MID-LEVEL FLOW ACROSS THESE
AREAS FOR STRONG DEEP LAYER SHEAR COMBINED WITH MODERATE INSTABILITY
WILL SUPPORT SUPERCELLS CAPABLE OF PRODUCING HAIL/DAMAGING WINDS AND
ISOLATED TORNADOES.

NOCTURNAL AND QG STRENGTHENING OF LLJ ACROSS THE SRN/CENTRAL PLAINS
WILL LIKELY RESULT IN THE DEVELOPMENT OF ONE OR MORE MCS/S THAT
SHOULD MOVE EWD ACROSS PORTIONS OF KS/NEB TONIGHT... POTENTIALLY
REACHING WRN MO/SWRN IA BY 12Z MONDAY. HAIL AND DAMAGING WINDS
SHOULD BE THE PRIMARY THREATS WITH THE OVERNIGHT ACTIVITY.

...SRN SD/NRN NEB TO SRN MN...
AN AXIS OF WEAKER INSTABILITY ACROSS THIS REGION COMBINED WITH
SUFFICIENT DEEP LAYER SHEAR...GIVEN AN INCREASE IN MID-LEVEL WLY
FLOW AHEAD OF THE UPPER TROUGH...SHOULD PROVE FAVORABLE FOR A FEW
STRONG TO SEVERE STORMS ALONG AND AHEAD OF THE COLD FRONT. 
SUPERCELLS WILL BE POSSIBLE...THOUGH MARGINAL INSTABILITY SHOULD
LIMIT THE AREAL COVERAGE OF SEVERE ACTIVITY.

...NRN ROCKIES...
COLD MID-LEVEL TEMPERATURES /-16 TO -20 C AT 500 MB/ ASSOCIATED WITH
THE NW UPPER TROUGH AND SUFFICIENT DEEP LAYER SHEAR FOR STORM
ROTATION IS EXPECTED TO SUPPORT A FEW STRONG TO SEVERE
DIURNALLY-DRIVEN STORMS WITHIN MARGINALLY UNSTABLE AIR MASS.

...COASTAL SC/GA...
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A COLD FRONT AND SEA
BREEZE BOUNDARY FROM LATE MORNING INTO THE AFTERNOON.  MODERATE
INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR WILL SUPPORT
SUPERCELLS...BUT OVERALL SMALL AREAL COVERAGE WILL PRECLUDE THE
ISSUANCE OF A SLIGHT RISK ATTM.

..PETERS/BANACOS.. 06/20/2004

...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.