[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 070548
SWODY1
SPC AC 070546

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1246 AM CDT WED JUN 07 2006

VALID 071200Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MIDWEST SWD
INTO THE TN VLY...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN INTERMOUNTAIN WEST
EWD TO THE NRN PLAINS...

...SYNOPSIS...
UPPER FLOW WILL REMAIN HIGHLY AMPLIFIED ON WED.  THE ERN MEAN TROUGH
WILL BE MAINTAINED AS A MID-LEVEL SHORTWAVE TROUGH NOW MOVING
THROUGH THE UPPER MIDWEST MOVES SEWD TOWARD THE OH VLY.  THE
DOWNSTREAM CAROLINAS UPPER LOW WILL CONTINUE LIFTING NWD TOWARD NEW
ENGLAND.  IN THE WEST...A LARGE UPPER HIGH WILL SLOWLY SHIFT EWD
TOWARD THE HIGH PLAINS AS A MID-LEVEL IMPULSE MOVES TOWARD THE PAC
NW COAST.

IN THE LWR LVLS...A WEAK LOW ASSOCIATED WITH THE GRTLKS UPPER
SYSTEM WILL MOVE SEWD INTO OH WITH ANOTHER SPOT LOW LIKELY FORMING
UPSTREAM ACROSS SRN IND.  MEANWHILE...A WEAKENING FRONT WILL MOVE
SLOWLY SEWD REACHING A WRN OH/WRN TN/CNTRL TX LINE DURING WED EVE. 
A SECOND FRONT WILL EXTEND FROM ONT AND LKSUP WWD ACROSS SD INTO A
LOW OVER NRN ID AREA...AND A PAC COLD FRONT WILL MOVE INLAND ACROSS
PARTS OF WA/ORE/ID/WRN MT DURING THE PD.

...MIDWEST SWD TO THE TN VLY...
A BROKEN BAND OF CONVECTION WILL LIKELY CONTINUE SEWD ACROSS THE
CNTRL GRTLKS AND OH VLY REGION EARLY IN THE PERIOD.  THIS MAY RETARD
STRONG INSOLATION AND RESULTANT DESTABILIZATION DOWNSTREAM DURING
PEAK HEATING.  BUT...SIMILAR TO TUE...THERE WILL LIKELY BE A ZONE OF
AIR MASS RECOVERY ALONG/IMMEDIATELY AHEAD OF THE PRIMARY COLD FRONT
FROM IND SWWD INTO WRN TN BY TUE AFTN.

TSTMS ARE EXPECTED TO DEVELOP OVER THE CNTRL GRTLKS EARLY IN THE DAY
AS LARGE SCALE ASCENT ASSOCIATED WITH THE UPPER WAVE SPREADS SEWD. 
OTHER TSTMS WILL DEVELOP WITHIN THE STRONGER INSTABILITY AXIS LATER
IN THE AFTN FROM PARTS OF IND...SERN IL AND FAR W KY.  INCREASING
NWLY FLOW BENEATH THE BASE OF THE UPPER IMPULSE WILL ENHANCE
VERTICAL SHEAR AND SUBSEQUENT STORM ORGANIZATION WITH SUPERCELLS
POSSIBLE.  LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY
THREATS.  BUT...TORNADOES CANNOT BE RULED OUT DURING THE EARLY
EVENING HOURS ACROSS PORTIONS OF SRN IND...WRN KY AND PARTS OF
MIDDLE TN WHERE WSWLY LOW-LEVEL FLOW BECOMES COINCIDENT WITH NWLY
FLOW ALOFT.  ACTIVITY MAY DEVELOP A SUFFICIENT COLD POOL DURING THE
EVENING TO SUSTAIN A SEVERE THREAT INTO SCNTRL KY AND MIDDLE TN
UNTIL LATE EVENING.  BUT...STRENGTH OF THE ACTIVITY SHOULD LARGELY
FOLLOW THE DIURNAL CURVE WITH A DECREASING SEVERE THREAT DURING THE
OVERNIGHT HOURS.

...NRN ROCKIES TO THE NRN PLAINS...
AS LARGE SCALE HEIGHTS BEGIN TO FALL IN THE NWRN STATES...ELY
LOW-LEVEL FLOW WILL TEND TO STRENGTHEN ACROSS THE NRN HIGH PLAINS
INTO THE NRN ROCKIES.  THIS WILL ADVECT LOW-LEVEL MOISTURE WWD AND
BENEATH THE VERY STEEP LAPSE RATES IN PLACE...ENHANCING THE
INSTABILITY.  UPSLOPE FLOW AND WEAK PERTURBATIONS TRAVERSING THE
PERIPHERY OF THE UPPER RIDGE WILL AID IN TSTM DEVELOPMENT DURING THE
LATE AFTN/EVE FROM SRN MT/NRN WY EWD INTO THE BLACK HILLS AND NWRN
NEB.  THE ESELY LOW-LEVEL FLOW BENEATH WLY FLOW ALOFT WILL PRODUCE
CONSIDERABLE DIRECTIONAL SHEAR TO SUPPORT A FEW SEVERE TSTMS WITH
LARGE HAIL AND DAMAGING WINDS. ONE OR MORE MCS/S ARE LIKELY TO
EVOLVE WED NIGHT/EARLY THU ALONG THE NOSE OF THE LLJ MAX AND TO THE
N OF THE BAROCLINIC ZONE ACROSS NRN NEB AND WRN/CNTRL SD.  HAIL AND
GUSTY WINDS MAY ACCOMPANY THE STRONGER STORMS.

...NRN INTERMOUNTAIN WEST...
UPPER SHORT WAVE TROUGH OFF THE PAC NW COAST WILL MOVE INLAND ON
WED.  IN ADVANCE OF THIS SYSTEM...MID-LEVEL MOISTURE HAS ADVECTED
NWD AROUND THE PERIPHERY OF THE UPPER HIGH.  THIS INCREASE IN PW AND
PRESENCE OF PRE-EXISTING STEEP MID-TROPOSPHERIC LAPSE RATES WILL
DESTABILIZE THE ENVIRONMENT WITH MLCAPES APPROACHING 1700 J/KG WED
AFTN.  AS HEIGHT FALLS ASSOCIATED WITH THE UPPER TROUGH SPREAD ATOP
THIS INSTABILITY AXIS...TSTMS ARE LIKELY TO DEVELOP ALONG THE HIGHER
TERRAIN AND VCNTY THE BAROCLINIC ZONE OVER ERN ORE/EXTREME SERN WA
NEWD INTO NRN/CNTRL ID AND WRN MT BY WED MID-AFTN.  VERTICAL SHEAR
OF 30-40 KTS WILL BE FAVORABLE FOR SUPERCELLS GIVING LARGE
HAIL...DAMAGING WINDS AND A TORNADO OR TWO.

...SRN PLATEAU...
PW VALUES CONTINUE TO INCREASE ACROSS THE SWRN STATES OWING TO
ACTIVE CONVECTION ON TUE AND DEEP SLY FLOW.  THE MID-LEVEL MOISTURE
PLUME WILL SPREAD NWWD INTO THE GRT BASIN ON WED AND MAY CONTRIBUTE
TO NUMEROUS TSTMS ACROSS MUCH OF ERN NV AND UT WED AFTN.  EARLY DAY
CLOUDS MAY DELAY CONVECTION ACROSS SERN AZ UNTIL LATER IN THE DAY. 
ENHANCED TROPOSPHERIC FLOW BETWEEN THE UPPER HIGH OVER THE SRN CO
AND THE UPPER LOW OVER BAJA NORTE WILL LIKELY ENCOURAGE STORMS TO
QUICKLY PROPAGATE NWWD.  STEEP LAPSE RATES AND RELATIVELY DRY
SUB-CLOUD LAYERS WILL INCREASE THE RISKS FOR DAMAGING WIND GUSTS AND
POSSIBLY HAIL.

...SRN MS VLY...
REMNANT MCV WILL MOVE SWD ACROSS THE SRN LA DURING THE LATE MORNING
AND AFTN WED.  IF CLOUD DEBRIS FROM OVERNIGHT STORMS DOES NOT
CONTAMINATE THE HEATING PROCESS...THERE WILL BE A LOW RISK OF
ORGANIZED TSTMS DEVELOPING ALONG RESIDUAL BOUNDARIES.  LARGE HAIL
AND DAMAGING WINDS APPEAR TO BE THE MAIN THREATS.  ACTIVITY SHOULD
MOVE OFFSHORE DURING THE EVE.

..RACY/GRAMS.. 06/07/2006