ZCZC SPCSWODY1 ALL
ACUS01 KWNS 270608
SPC AC 270608

STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.

VALID 271200Z - 281200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM DUG
40 ESE SAD 45 W ONM 35 SSW ABQ 35 SSE SAF 40 WNW TCC 40 WSW CVS
20 SSE ROW 35 W CNM 65 WNW MRF.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM INL
15 SSW DLH 25 N RST 20 ESE FRM 30 ENE HON 25 SE BIS 60 N ISN.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
10 NNW HUL 15 E AUG 25 N PSM 20 SSW BOS 25 S ORH 20 W BDL
15 NNE PSF 15 SW LEB 20 NW MWN 45 N BML.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 65 SW TUS 45 NW TUS
60 E PHX 25 E SOW 70 E SOW 40 S GNT 15 NE GNT 10 N 4SL 55 NNW LVS
45 WNW RTN 10 ESE LHX 40 NE MCK 40 E MHN 50 SW RAP 35 SW GCC COD
30 WSW BZN 40 SSW MSO 30 NNW S06 90 ENE 63S ...CONT... 75 E ELO
45 NW IMT 30 SSE IMT 50 NNW MBL 15 NW OSC 45 E MBS 15 SE SBN
20 NNW BMI 45 NNE COU 10 ESE OJC 50 SSW EMP 15 NNE CDS 50 SE MAF
60 NNW SAT 30 NNW CLL 35 NNW POE 30 NNE GWO 45 NNW MSL 40 ESE BWG
35 SW CRW 20 WSW MRB 15 ESE IPT 20 S UCA 10 SW MSS.


...SYNOPSIS...
LARGE SCALE UPPER TROUGH WILL BE THE DOMINANT FEATURE ACROSS THE
NRN THIRD OF THE CONUS WITH A BELT OF MODEST MID LEVEL FLOW
ENTERING THE LOWER U.S. OVER THE PACIFIC NORTHWEST...EXTENDING
ACROSS THE NRN PLAINS AND MIDWEST BEFORE TURNING CYCLONICALLY
ACROSS THE ERN GREAT LAKES AND NEW ENGLAND. TWO SHORT WAVE IMPULSES
WILL PROGRESS THROUGH THIS LARGER SCALE FLOW...ONE LIFTING NEWD
FROM THE GREAT LAKES AREA WITH ITS ASSOCIATED COLD FRONT MOVING
ACROSS THE NORTHEAST. THE OTHER LOW-AMPLITUDE IMPULSE WILL DEVELOP
SEWD ACROSS THE DAKOTAS WITH SURFACE LOW PRESSURE CONSOLIDATING
ALONG A DEVELOPING WARM FRONT OVER THE ERN DAKOTAS AND PROGRESSING
INTO WRN MN OVERNIGHT. FINALLY...INCREASINGLY DIFFUSE REMNANT
FRONTAL ZONE WILL LIKELY STALL ACROSS THE TN VALLEY/SOUTHEAST AND
EXTEND SWWD TO THE TX GULF COAST...AND THEN WWD/NWWD ACROSS NRN
MEXICO INTO THE SRN ROCKIES.

...NM/FAR WEST TX...
MOISTURE FOCUSED ALONG AND BEHIND RESIDUAL FRONTAL ZONE SPREADING 
ACROSS SWRN/CNTRL NM...COUPLED WITH STRONG HEATING /TEMPS IN THE
MID 80S F/...WILL PRODUCE VERY STRONG AND WEAKLY CAPPED INSTABILITY
ACROSS THE UPPER RIO GRANDE VALLEY THIS AFTERNOON. ETA AND ETAKF
FCST SOUNDINGS ARE IN GOOD AGREEMENT INDICATING MLCAPE VALUES
AROUND 2000 J/KG AND 8-9C/KM MID LEVEL LAPSE RATES ACROSS THE SLGT
RISK AREA BY 20 UTC. DESPITE WEAK LARGE SCALE FORCING FOR ASCENT
ACROSS THE REGION...DIURNAL AND OROGRAPHIC FORCING AND DEEPER
MIXING/CONVERGENCE ALONG EFFECTIVE DRY LINE/FRONT NEAR THE AZ/NM
BORDER SHOULD AID STORM INITIATION DURING THE AFTERNOON. WEAK SLY
LOW LEVEL FLOW TOPPED BY 20-30KT WNWLY FLOW ALOFT WILL YIELD DEEP
LAYER SHEAR VALUES SUPPORTIVE OF STORM ROTATION AND THE PRODUCTION
OF LARGE HAIL. A FEW STRONG DOWNBURSTS/OUTFLOWS COULD ALSO DEVELOP
AS STORMS DRIFT SLOWLY SOUTH OFF THE HIGHER TERRAIN AND ACROSS THE
LOWER DESERTS.

...NRN PLAINS...
STRONG MID/UPPER JET STREAK WILL SPREAD SEWD FROM ERN MT AND INTO
SD DURING THE DAY AND RESULT IN SURFACE CYCLOGENESIS AND
INTENSIFYING WARM AIR ADVECTION AND LIFT ACROSS THE ERN DAKOTAS BY
AFTERNOON. DESPITE SOMEWHAT LIMITED BOUNDARY LAYER MOISTURE WITH
SURFACE DEW POINTS FCST TO REMAIN IN THE 55-60F RANGE...COLD MID
LEVEL TEMPS AND MOISTENING WILL COMBINE WITH DYNAMIC FORCING TO
SUPPORT AN EXPANDING AREA OF CONVECTION. STRENGTHENING NWLY MID
LEVEL FLOW ATOP 10-15KT WLY BOUNDARY LAYER WINDS WILL RESULT IN
STRONG VERTICAL SPEED SHEAR...WITH HIGHER LOW LEVEL SRH INVOF
SURFACE LOW/WARM FRONT. EXPECT A FEW SUPERCELLS TO DEVELOP IN THIS
AREA AND SPREAD SEWD DURING THE EVENING WITH A HAIL/WIND AND ISOLD
TORNADO THREAT. ACTIVITY MAY MERGE INTO A SMALL MCS DURING THE LATE
EVENING AND CONTINUE DEVELOPING EWD ACROSS THE MS RIVER OVERNIGHT.

...NEW ENGLAND...
AFTER A NUMBER OF VERY WARM AND HUMID DAYS ACROSS NEW ENGLAND...
RELIEF IN THE FORM OF A COLD FRONT IS ON THE WAY. ETAKF AND ETA
WERE INDICATING THE DEVELOPMENT OF A PREFRONTAL/THERMAL TROUGH AXIS
FROM ERN MA NEWD INTO INTERIOR ME BY LATE MORNING COINCIDENT WITH
VERY WARM/MOIST LOW LEVEL AIRMASS /TEMPS IN THE 80S AND DEW POINTS
IN THE MID 70S/. WHILE ETA KEEPS THIS AREA CAPPED THROUGH THE
AFTERNOON AND DEVELOPS PRIMARY CONVECTIVE BAND ALONG THE COLD FRONT
MOVING INTO ERN NY/VT...THE ETAKF INDICATES THE POTENTIAL FOR
VIGOROUS CONVECTIVE DEVELOPMENT OCCURING WITHIN THE TROUGH BEFORE
18 UTC. DESPITE THESE DIFFERENCES...THERE IS GOOD AGREEMENT IN THE
MAGNITUDE OF INSTABILITY AND DCAPE ACROSS THE REGION WITH MLCAPE
VALUES RANGING FROM 1500 TO 3000 J/KG....AND DCAPE VALUES OVER 1000
J/KG. LARGE SCALE ASCENT WITHIN RIGHT ENTRANCE REGION OF UPPER
JET..AND LIFT ALONG/AHEAD OF THE FRONTAL ZONE AND TROUGH SHOULD
PROMOTE ONE OR MORE SEGMENTED CONVECTIVE LINES WITH ISOLD TO
SCATTERED WIND DAMAGE POTENTIAL ACROSS THE SLGT RISK AREA BETWEEN
18-00 UTC.
 
..CARBIN/JEWELL.. 06/27/03

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