[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 020558
SWODY1
SPC AC 020556

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1256 AM CDT SUN JUL 02 2006

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL/NRN
PLAINS...ACROSS THE MIDWEST/UPPER OH VALLEY...TO THE NORTHEAST...

...SYNOPSIS...
GENERALLY WEAK HEIGHT FALLS WILL ACCOMPANY A PAIR OF LOW AMPLITUDE
SHORT WAVE TROUGHS EMBEDDED WITHIN A LARGER SCALE BAND OF MODEST
WNWLY FLOW FROM SCNTRL CANADA TO THE NORTHEAST THIS PERIOD. THE LEAD
DISTURBANCE...CURRENTLY CROSSING THE GREAT LAKES...WILL CONTINUE
EAST TO QUEBEC BEFORE MOVING ACROSS THE ST. LAWRENCE VALLEY TO NRN
NEW ENGLAND THROUGH SUNDAY NIGHT. THE FRONTAL ZONE ASSOCIATED WITH
THIS FEATURE...EMBEDDED WITHIN A RELATIVELY STRONG DEEP-LAYER FLOW
FIELD...WILL SPREAD ESEWD ACROSS THE NORTHEAST THROUGH TONIGHT.

THE WRN EXTENSION OF THIS FRONT WILL REMAIN QUASI-STATIONARY FROM
THE UPPER OH VALLEY/MIDWEST TO THE CNTRL PLAINS. WEAK MID/UPPER
LEVEL PERTURBATIONS...EMANATING IN PART FROM WIDESPREAD DEEP
CONVECTION ACROSS THE ROCKIES...IN COMBINATION WITH PERSISTENT MASS
INFLOW ON THE NOSE OF GREAT PLAINS LOW LEVEL JET...WILL MAINTAIN THE
PROSPECTS FOR ASCENT ALONG THIS PORTION OF THE STALLED BOUNDARY.

THE NEXT UPSTREAM IMPULSE IN THE FASTER NWLY FLOW ACROSS SRN CANADA
AND THE NRN U.S. WILL BRING A WEAK COLD FRONT ACROSS THE NRN PLAINS
AND UPPER MS VALLEY THROUGH EARLY MONDAY.

...NORTHEAST...
CONVECTION IS FORECAST TO CONTINUE SPREADING EAST FROM THE GREAT
LAKES AND UPSTATE NY INTO NRN NEW ENGLAND EARLY TODAY AIDED BY LIFT
AND WEAK DESTABILIZATION ON THE NOSE OF WLY LOW LEVEL JET. IN THE
WAKE OF THIS EARLY WARM CONVEYOR BELT CONVECTION...WEAK TO MODERATE
INSTABILITY /MLCAPE 500-1500 J PER KG/ SHOULD DEVELOP IN AN AXIS
FROM SRN NY/NRN PA ENEWD ACROSS SRN/CNTRL NEW ENGLAND. SCATTERED
CONVECTION OCCURRING ALONG THE WEAK COLD FRONT/WIND SHIFT SHOULD
INCREASE IN BOTH COVERAGE AND INTENSITY AS GREATER INSTABILITY IS
REALIZED AND FRONTAL FORCING SPREADS ESEWD. RELATIVELY STRONG WLY
FLOW THROUGH THE TROPOSPHERE AND POTENTIALLY STEEP LOW LEVEL LAPSE
RATES SUGGEST FAST MOVING BANDS/CLUSTERS OF STORMS WITH A TENDENCY
TO BOW OUT AND PRODUCE WIND DAMAGE. STRONG LOW LEVEL SHEAR...THE
POSSIBILITY OF RESIDUAL OUTFLOW/DIFFERENTIAL HEATING
BOUNDARIES...AND LOCALLY LOWER LFC...MAY ENHANCE THE THREAT FOR A
FEW SUPERCELLS WITH LARGE HAIL AND PERHAPS A TORNADO FOR ANY CELLS
REMAINING DISCRETE. GREATEST SEVERE POTENTIAL APPEARS TO EVOLVE FROM
PA TO NRN NJ/SERN NY...AND ACROSS SWRN NEW ENGLAND THROUGH LATE
AFTERNOON WHERE GREATEST CHANCE FOR STRONG DESTABILIZATION WILL
OCCUR AHEAD OF STRENGTHENING MID LEVEL FLOW.

...OH VALLEY/MIDWEST TO CNTRL HIGH PLAINS...
MODERATE INSTABILITY /MLCAPES OF 1500-2500 J PER KG/ WILL DEVELOP
ALONG THE QUASI-STATIONARY FRONT FROM OH WWD TO THE CNTRL PLAINS
GIVEN STEEP LAPSE RATES/STRONG HEATING AND RELATIVELY MOIST LOW
LEVEL AIR MASS. PERSISTENT LOW-LEVEL CONVERGENCE...COUPLED WITH THE
INFLUENCE OF WEAK IMPULSES EMBEDDED WITHIN MID-LEVEL FLOW...WILL AID
IN THE DEVELOPMENT OF SCATTERED AFTERNOON AND EVENING STORMS. WHILE
STRONGER WLY FLOW WILL RESIDE A BIT NORTH OF THE GREATEST
INSTABILITY...SUFFICIENT EFFECTIVE SHEAR WILL EXIST FOR ORGANIZED
SEVERE STORMS...INCLUDING A FEW SUPERCELLS AND BOWING STRUCTURES.
LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY SEVERE WEATHER
HAZARDS.

MOIST UPSLOPE FLOW INTO HIGHER HEATED TERRAIN WILL OVERCOME
INHIBITION AND LEAD TO STORM DEVELOPMENT ACROSS CO/WY. THIS
ACTIVITY...SIMILAR TO SATURDAY...WILL MOVE SLOWLY EAST INTO MOIST
POST-FRONTAL AIR MASS WHERE SHEAR AND INSTABILITY WILL MARGINALLY
SUPPORT SOME HAIL AND WIND POTENTIAL. ONE OR TWO OF THESE CLUSTERS
OF STORMS MAY PERSIST WELL INTO THE NIGHT AS NOCTURNAL LOW LEVEL JET
INTENSIFIES AND MAINTAINS MASS INFLOW/LIFT ACROSS THE FRONTAL ZONE.

...NRN PLAINS...
LOW LEVEL WARM AIR ADVECTION IS EXPECTED TO INTENSIFY LATE IN THE
PERIOD AHEAD OF SHORT WAVE TROUGH DEVELOPING SEWD FROM SCNTRL
CANADA. STEEP LAPSE RATES...INCREASING ASCENT AND MOISTENING... FROM
THE DAKOTAS TO MN...MAY SUPPORT THE DEVELOPMENT OF A LATE-NIGHT MCS
ACROSS THESE AREAS THROUGH EARLY MONDAY. A FEW HAIL EVENTS APPEAR
POSSIBLE WITH THIS SCENARIO.

..CARBIN/GUYER.. 07/02/2006