[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 290105
SWODY1
SPC AC 290103

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0803 PM CDT FRI JUL 28 2006

VALID 290100Z - 291200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS UPPER MIDWEST...

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SWRN CONUS...

...SYNOPSIS...
UPPER AIR PATTERN IS CHARACTERIZED BY PROGRESSIVE NRN STREAM FLOW
BELT...DOWNSTREAM FROM STRONG TROUGH LOCATED OFF BC COAST. 
SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN
NEW ENGLAND -- WILL MOVE OFFSHORE TONIGHT.  RELATED SFC TROUGH AND
COLLOCATED MCS ALREADY HAS WEAKENED AND MOVED LARGELY
OFFSHORE...DROPPING SVR POTENTIAL OVER NERN CONUS.  FARTHER
W...WELL-DEFINED SFC COLD FRONT WILL CONTINUE MOVING SEWD FROM ONT
AND LS ACROSS NERN MN...REMAINDER LS...AND UPPER MI THROUGH
REMAINDER PERIOD.  WRN PORTION OF THIS FRONT -- NOW ANALYZED INVOF
ND/SD BORDER -- SHOULD REMAIN STATIONARY OR DRIFT SLIGHTLY NWD E OF
COMBINED LEE/FRONTAL-WAVE CYCLONE THAT IS ANALYZED ACROSS NWRN SD. 
MEANWHILE...MID-UPPER LEVEL LOW REMAINS WELL DEFINED IN MOISTURE
CHANNEL IMAGERY OVER AZ/NM BORDER...WITH WEAK WWD TO SWWD DRIFT
ANTICIPATED THROUGH TONIGHT.

...AZ...
SCATTERED-NUMEROUS TSTMS HAVE DEVELOPED FROM SWRN UT SSEWD ACROSS
W-CENTRAL AZ...SOME OF WHICH HAVE PRODUCED LARGE HAIL. REF SPC WW
651 AND RELATED MESOSCALE DISCUSSION FOR NEAR-TERM DETAILS.  WELL
MIXED BOUNDARY LAYERS WILL SUPPORT POTENTIAL FOR EVOLUTION INTO
FORWARD-PROPAGATING MCS.  ASSOCIATED DAMAGING WIND POTENTIAL MAY
INCREASE WSWWD ACROSS LOWER ELEVATIONS THROUGH REMAINDER EVENING AS
ACTIVITY PROPAGATES THAT WAY...WITH HELP FROM MIDLEVEL NELYS
APPARENT IN VWP FROM FLG/PHX.  BROAD AREA OF FAVORABLE INSTABILITY
-- WITH MLCAPES 1500-3000 J/KG -- REMAINS ACROSS SWATH FROM SWRN AZ
NWWD ACROSS CO RIVER VALLEY REGION AHEAD OF THIS ACTIVITY...IN
PROSPECTIVE INFLOW REGION.

...UPPER MIDWEST...
REF SPC WW 650 AND ACCOMPANYING MESOSCALE DISCUSSIONS FOR NOWCAST
DETAILS REGARDING SVR THREAT WITH ONGOING ACTIVITY OVER NRN WI AND
UPPER MI.  AS WRN GREAT LAKES AREA OF CONVECTION GRADUALLY
WEAKENS...GREATEST SVR POTENTIAL IS FCST TO TRANSFER WWD TO ND AND
PERHAPS EXTREME NRN SD NEXT FEW HOURS. SVR TSTMS MAY EVOLVE FROM
ONGOING HIGH-BASED CONVECTION INVOF ND/SD BORDER...IN ENVIRONMENT OF
FAVORABLE DEEP-LAYER SHEAR.  INTENSELY HEATED/MIXED SUBCLOUD LAYERS
WILL FAVOR MAINTENANCE OF STRONG-SVR DOWNDRAFTS TO SFC...AS WELL AS
ANY LARGE HAIL THAT MAY BE GENERATED ALOFT.

00Z BIS RAOB SHOWS STRONG CAP N OF SFC FRONT BUT ALSO STRONG LOW
LEVEL WAA.  THIS PROCESS SHOULD CONTINUE THROUGH REMAINDER TONIGHT
OVER MUCH OF CENTRAL/ERN ND...SHIFTING INTO W-CENTRAL/NWRN MN...WITH
ENOUGH MOISTENING THROUGH AROUND 06Z TO SUPPORT PARCELS
ISENTROPICALLY RAISED TO LFC.  THIS PROCESS...COMBINED WITH
POTENTIAL FOR DAMAGING WIND PRODUCING MCS EVOLVING FROM CURRENT
SFC-BASED DEVELOPMENT FARTHER W...INDICATES RISK FOR SVR SHOULD BE
MAINTAINED OVER THIS REGION FOR OVERNIGHT HOURS.  ONE OR TWO MCS
SHOULD EVOLVE OVERNIGHT...MOVING GENERALLY ESEWD ACROSS MN AND
CARRYING SVR POTENTIAL OVER INTO DAY-2 PERIOD.

..EDWARDS.. 07/29/2006