[LeArc] DAY 1 CONVECTIVE OUTLOOK

[Duane Whittingham]

STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.
   
VALID 061200Z - 071200Z
   
THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
40 SW P07 30 SSW FST LBB RSL HLC IML 50 N IML MHN SUX FOD LNR OSH
TVC 40 NE OSC ...CONT... ROC 45 ESE BFD PSB AOO CRW LEX EVV SGF
TUL DRT.
   
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 60 NNE BML ORH WAL
RDU HKY AVL AHN MCN 30 SSE CSG MGM 0A8 MKL 30 SSE POF 55 SSE HRO
PRX SEP 25 S DRT.
   
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 85 S MRF LBB RSL HLC
IML EVW OWY 45 W BOI LWS 3TH GTF 3HT BIL 4BQ REJ Y22 GFK 55 NW CMX.
   
--- SYNOPSIS ---
BROAD FETCH OF SWLYS ALOFT WILL PERSIST ACROSS MOST OF CENTRAL
CONUS -- GENTLY CURVING ANTICYCLONICALLY TO ZONAL FLOW OVER GREAT
LAKES/N-CENTRAL APPALACHIAN REGIONS.  SEVERAL MINOR PERTURBATIONS
ARE EXPECTED TO EJECT NEWD IN THIS FLOW FIELD...FROM PACIFIC
NW/GREAT BASIN LONGWAVE TROUGH.  THIS WILL INCLUDE SIGNIFICANTLY
DEAMPLIFIED REMNANTS OF SRN CA/NRN AZ TROUGH -- MOVING NEWD ACROSS
SRN ROCKIES/SRN HIGH PLAINS DURING LATTER HALF OF PERIOD.  AT
SURFACE...CYCLONE ANALYZED ATTM OVER SERN CO IS FORECAST TO MOVE
EWD ALONG SURFACE TROUGH TO CENTRAL KS -- INTERSECTING DRYLINE --
WHILE COLD FRONT MOVES SWD THROUGH N-CENTRAL PLAINS.  COLD FRONT
MAY MERGE INTO THIS LOW OVER CENTRAL/NRN KS BY END OF PERIOD...
WHILE BECOMING QUASISTATIONARY EWD TOWARD CENTRAL/NRN IL.
   
MANY MESOSCALE DETAILS ARE YET TO BE DETERMINED IN BOTH PORTIONS OF
OUTLOOK DESCRIBED BELOW...THEREFORE TOO SOON TO FORECAST
SUFFICIENTLY CONCENTRATED AREA OF SEVERE TO UPGRADE CATEGORICAL
RISK WITHIN BROADER SLGT.  
  
--- SRN/CENTRAL PLAINS ---
WIDELY SCATTERED TSTMS ARE EXPECTED TO DEVELOP OVER WRN PORTIONS
OUTLOOK AREA DURING AFTERNOON...SOME OF WHICH WILL BE SUPERCELLULAR
WITH ALL SEVERE MODES POSSIBLE.  OUTLOOK IS PROGRESSIVELY MORE
CONDITIONAL WITH SWD EXTENT AWAY FROM FRONT THROUGH KS/OK AND NW TX
-- WHERE STRONG CAP MAY PRECLUDE DEVELOPMENT ALTOGETHER OR KEEP
COVERAGE VERY ISOLATED.  CAP IS EXPECTED TO WEAKEN AGAIN SWD
THROUGH PERMIAN BASIN/TRANS PECOS REGIONS HOWEVER -- WHERE INTENSE
HEATING AND DEEP MIXING MAY CONTRIBUTE TO DEVELOPMENT OF HIGH BASED
TSTMS WITH LARGE HAIL AND SEVERE GUSTS FOR A FEW HOURS IN LATE
AFTERNOON.
   
PRIMARY INITIATIVE FOCI SHOULD BE DRYLINE AND ANY OF SEVERAL
ESIDUAL OUTFLOW BOUNDARIES LEFT OVER FROM DAY-1 CONVECTION --
WITHIN SWATH FROM IA TO W TX.  BOUNDARY LAYER FLOW MAY BE VEERED
COMPARED TO PREVIOUS DAY -- AS STRONGEST ISALLOBARIC/ISALLOHYPSIC
FORCING SHIFTS TO N AND NE OF AREA.  THIS WOULD REDUCE MESO ALPHA
SCALE CONVERGENCE AND SRH...THOUGH SMALLER SCALE BOUNDARY EFFECTS
AND STRONG DEEP-TROPOSPHERIC SHEAR SHOULD HELP TO MAINTAIN RISK OF
SUPERCELLS.  MODIFIED ETAKF FORECAST SOUNDINGS YIELD 2500-3700
MLCAPE WITH MID LEVEL LAPSE RATES COMMONLY ABOVE 8 DEG C/KM. 
SIGNIFICANT HAIL IS LIKELY WITH ANY STORMS WHICH DO DEVELOP IN THIS
ENVIRONMENT. 
   
MOST FAVORED AREA FOR DEVELOPMENT OF NOCTURNAL MCS APPEARS TO BE
INVOF DECELERATING FRONT FROM NERN KS/SERN NEB EWD ACROSS
MO...WHERE SR INFLOW AND MOISTURE TRANSPORT WILL BE IDEALLY
JUXTAPOSED NEAR NOSE OF 35-45 KT LLJ OVERNIGHT.
  
--- MID MS VALLEY/ERN GREAT LAKES STATES ---
ONGOING CONVECTION EARLY IN PERIOD IS EXPECTED TO BE LARGELY NON-
SEVERE -- PERHAPS WITH A FEW WIND OR HAIL EVENTS EARLY. 
HOWEVER...MOISTURE ADVECTION AND DIABATIC HEATING ARE EXPECTED TO
CONTRIBUTE SUBSTANTIAL LOW LEVEL DESTABILIZATION -- WITH 1000-2000
J/KG MLCAPE POSSIBLE BY EARLY-MID AFTERNOON.  WITH MEAN 
TROPOSPHERIC FLOW ABOVE 40 KT AND 50 KT WINDS IN LOW LEVELS IN
UNIDIRECTIONAL WIND PROFILE...POTENTIAL EXISTS FOR SWATH OF
DAMAGING CONVECTIVE WIND SOMEWHERE ACROSS MI/INDIANA/OH DURING
AFTERNOON/EVENING.  HEATING MAY BE LIMITED...HOWEVER...BY
CLOUD/PRECIP RESIDUE FROM MORNING ACTIVITY.
    
..EDWARDS.. 05/06/02

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Duane Whittingham (N9SSN) - Producer
Tom and Darryl Radio Shows
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