[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 140102
SWODY1
SPC AC 140100

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0800 PM CDT THU APR 13 2006

VALID 140100Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS UPPER MS VALLEY TO WRN WV...

...SYNOPSIS...
SYNOPTIC UPPER AIR PATTERN SHOULD REMAIN DOMINATED BY NEARLY ZONAL
FLOW ACROSS NRN CONUS...RIDGING AND HIGH HEIGHTS FROM 4-CORNERS
REGION TO FL...AND NEARLY CUT-OFF MID/UPPER LEVEL LOW OFFSHORE SRN
CA.  MOISTURE CHANNEL IMAGERY INDICATES SHORTWAVE TROUGH OVER SERN 
SK...SWRN MB AND NRN ND.  SUBTLE PERTURBATION IS EVIDENT IN MOISTURE
CHANNEL IMAGERY AND VWP/PROFILER TIME SERIES OVER CENTRAL IA...A
FEATURE WHICH TRACKS BACK TO AT LEAST 13/12Z OVER NERN CO.  THIS
FEATURE -- NOT DEPICTED IN SPECTRAL BUT EVIDENT IN LATEST RUC/ETA --
SHOULD PHASE WITH NRN STREAM TROUGH TO FORM POSITIVELY TILTED
SHORTWAVE THAT WILL MOVE ESEWD ACROSS NRN ONT AND UPPER GREAT LAKES
REGION OVERNIGHT.

SFC ANALYSIS SHOWS DIFFUSE COLD FRONT MOVING EWD ACROSS MN AND SEWD
ACROSS CENTRAL MEB...WITH STRONGER CAA REINFORCEMENT OVER CENTRAL ND
AND WRN SD.  WAVY DRYLINE MEANDERS FROM S-CENTRAL KS NWD TO SERN
NEB...THEN ENEWD ACROSS NRN IA...INTERSECTING WARM FRONT OVER SERN
MN.  DIFFUSE WARM FRONT SHOULD LIFT NWD ACROSS REMAINDER SERN MN AND
MUCH OF WI OVERNIGHT.  WEAK SFC CYCLOGENESIS IS POSSIBLE OVERNIGHT
ALONG WARM FRONT...ACROSS PORTIONS WI/LM.  ERN PORTION WARM FRONT
SHOULD MOVE SLOWLY NWD OVER NRN INDIANA...SRN LM AND PERHAPS SWRN
LOWER MI.

...IA/MN TO UPPER OH VALLEY...
REF WW 178 AND ASSOCIATED MESOSCALE DISCUSSIONS FOR NEAR-TERM INFO
ON UPPER MS VALLEY SEVERE POTENTIAL.

WEAK IA SHORTWAVE TROUGH CORRESPONDED WELL TO FIELD OF CUMULIFORM
CLOUDS THAT EVOLVED INTO CURRENT CENTRAL IA TSTM COMPLEX...ONCE
ASSOCIATED FIELD OF LARGE SCALE ASCENT MOVED ATOP STRONGEST BOUNDARY
LAYER HEATING AND WEAKEST CINH.  THIS FEATURE WILL HELP TO MAINTAIN
FAVORABLE LARGE SCALE ENVIRONMENT FOR SEVERE -- BOTH IN TERMS OF
DEEP-LAYER SHEAR AND STEEPENED MIDLEVEL LAPSE RATES -- AS IT MOVES
ACROSS IL/INDIANA OVERNIGHT.

FIELDS OF HIGH-BASED/MIDLEVEL CONVECTION IS EVIDENT IN VIS IMAGERY
OVER ERN DAKOTAS AND NWRN WI E OF MSP...EACH OF WHICH HAS PRODUCED A
FEW LIGHTNING STRIKES. DAKOTAS ACTIVITY IS ASSOCIATED WITH
STRONGEST LARGE SCALE ASCENT AHEAD OF NRN STREAM TROUGH...AND MAY
INTENSIFY AS IT MOVES EWD PAST SFC FRONTAL ZONE INTO MN...WITH
ACCESS TO SOMEWHAT MORE ROBUST MOISTURE FIELD ABOVE SFC.  WRN WI
ACTIVITY MAY INCREASE AS BOUNDARY LAYER DECOUPLES AND LLJ
STRENGTHENS IN INFLOW SECTOR.

ANY OF THESE AREAS OF CONVECTION MAY EVOLVE INTO MCS
OVERNIGHT...MOVING SEWD ACROSS GREAT LAKES TOWARD LOWER MI...AND
OH/WV REGION. MOST PROBABLE AREA FOR LONG-LIVED MCS EVOLUTION IS
OVER ERN IA AND NRN IL...EVOLVING FROM ONGOING MIX OF MULTICELLS AND
SUPERCELLS OVER IA.  ASSOCIATED POTENTIAL FOR DAMAGING GUSTS AND
LARGE HAIL SHOULD EXTEND ESEWD ACROSS INDIANA/OH/WV/WRN PA AS THIS
ACTIVITY MOVES THROUGH WRN PORTION OF INCREASINGLY MOIST...45-60 KT
LLJ.

..EDWARDS.. 04/14/2006