[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 221951
SWODY1
SPC AC 221949

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0249 PM CDT THU SEP 22 2005

VALID 222000Z - 231200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 NNE
ERI 30 ESE MFD 20 NE IND 20 SW DNV 30 SSE BRL 20 N BRL 30 NNW MLI 20
SE MKE 30 WSW MBS 75 NE MTC.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NE EFK PSM 25 S
BDL 25 WNW EWR HGR 30 NNE CHO 10 SE RIC 55 E ECG ...CONT... 65 ESE
PSX 20 SW ESF 35 W JAN 40 WNW CBM 25 N MSL 20 WNW BNA 30 NNW HOP 25
NNE UNO UMN 20 SE END 40 N CDS 40 SE ROW 35 SSE ELP ...CONT... 85 S
GBN 10 S PHX 10 SE FLG 20 SW BCE 50 NW 4HV VEL 50 NNW CAG 40 NNW LAR
10 W BFF 45 SW MHN 35 SSW EAR 15 SSW LNK 50 W DSM 50 NW DBQ 20 E GRB
25 NNW APN.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SW DLN 35 SSW LVM
40 SW COD 25 NW BPI 20 W SLC 50 S ENV 40 SSE EKO 45 NNE BAM 50 NNW
OWY 50 WNW SUN 25 SW DLN.

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT
ACROSS PARTS OF THE SRN GREAT LAKES AND NRN OH VALLEY...

...SYNOPSIS...
AFTERNOON WATER VAPOR IMAGERY SHOWS LOW AMPLITUDE SHORTWAVE TROUGH
TRANSLATING NEWD THROUGH THE CNTRL GREAT LAKES...EMBEDDED WITH A
BELT OF 45-60 KT WSWLY MID-LEVEL FLOW FROM THE MID MO VALLEY ACROSS
THE GREAT LAKES.  IN THE LOW-LEVELS...LATEST MESOANALYSIS INDICATED
A SURFACE LOW OVER CNTRL LOWER MI WITH ATTENDANT COLD FRONT TRAILING
SWWD FROM THIS FEATURE ACROSS NWRN IL...NRN MO AND INTO SERN KS. 
MEANWHILE...A WARM FRONT/OUTFLOW COMPOSITE BOUNDARY WAS SLOWLY
LIFTING NEWD THROUGH WRN IND INTO SWRN LOWER MI WITH TEMPERATURES
NOW INTO THE LOWER TO MID 90S AHEAD OF COLD FRONT OVER IL.

...SRN GREAT LAKES/NRN OH VALLEY...

TSTMS ARE INCREASING IN BOTH COVERAGE AND INTENSITY THIS AFTERNOON
FROM VICINITY OF COLD FRONT N OF CHICAGO EWD ACROSS CNTRL LOWER MI
TO N OF DETROIT.  WHILE MAJORITY OF STORMS ACROSS LOWER MI ARE
SLIGHTLY ELEVATED ABOVE A SHALLOW SURFACE INVERSION...THE WRN-MOST
STORMS ARE LIKELY SURFACE-BASED.  18Z...ILX SOUNDING IS
REPRESENTATIVE OF WARM SECTOR AIR MASS...EXHIBITING STEEP
LOW/MID-LEVEL LAPSE RATES...MLCAPES OF 1000-2000 J/KG AND SOME
CAPPING FOR MEAN-MIXED PARCELS.  CONTINUED HEATING/DESTABILIZATION
WITHIN IMMEDIATE PRE-FRONTAL ZONE SHOULD SUPPORT ADDITIONAL STORM
DEVELOPMENT ALONG COLD FRONT AS WELL AS RETREATING WARM FRONT THIS
AFTERNOON AND EVENING.

LARGELY UNIDIRECTIONAL WINDS WITH HEIGHT AS OBSERVED ON REGIONAL
VWPS AND PROFILERS SUGGEST THE POTENTIAL FOR BOWING STRUCTURES...AND
PERHAPS A FEW SPLITTING SUPERCELLS WITH DAMAGING WINDS AND LARGE
HAIL BEING THE MAIN SEVERE WEATHER THREATS.  OTHER MORE ELEVATED
STORMS OVER CNTRL LOWER MI WILL REMAIN CAPABLE OF MAINLY ISOLATED
HAIL.  EXPECT ACTIVITY TO GRADUALLY MOVE/DEVELOP EWD OR SEWD ACROSS
PORTIONS OF NRN IL/NRN IND/SRN LOWER MI AND EVENTUALLY INTO NRN OH
TONIGHT.  THIS SEVERE WEATHER THREAT SHOULD TEND TO WEAKEN LATER
TONIGHT AS AIR MASS COOLS AND STABILIZES.

...4-CORNERS REGION...

WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH/VORTICITY MAXIMUM
SHIFTING EWD ACROSS NRN AZ WITH DOWNSTREAM REGION OF FORCING
CONTRIBUTING TO INCREASING STORM ACTIVITY OVER ERN AZ/WRN NM/SERN UT
AND SRN CO.  RUC FORECAST SOUNDINGS INDICATE THAT AMBIENT
ENVIRONMENT HAS BECOME WEAKLY UNSTABLE THIS AFTERNOON...LARGELY AS A
RESULT OF STEEPENING LOW/MID-LEVEL LAPSE RATES.  GIVEN THESE STEEP
LAPSE RATES AND MODEST DEEP-LAYER VERTICAL SHEAR A FEW OF THE MOST
INTENSE STORMS WILL BE CAPABLE OF MARGINALLY SEVERE WINDS/HAIL
THROUGH THE REMAINDER OF THE AFTERNOON INTO THIS EVENING.

..MEAD.. 09/22/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.