[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 161954
SWODY1
SPC AC 161952

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0152 PM CST THU FEB 16 2006

VALID 162000Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EARLY EVE ACROSS
PARTS OF THE MID MS AND LWR OH VLYS....

...OZARK PLATEAU INTO GREAT LAKES....
WAVE SHIFTING NORTHEASTWARD ALONG SHARP FRONTAL ZONE THROUGH THE
MIDDLE MISSISSIPPI VALLEY IS STILL RELATIVELY LOW IN AMPLITUDE. 
HOWEVER...MODELS CONTINUE TO SUGGEST SURFACE LOW WILL BECOME BETTER
DEFINED LATER THIS AFTERNOON ACROSS NORTHEASTERN ILLINOIS/NORTHERN
INDIANA...BEFORE MORE RAPID DEEPENING OCCURS AS IT PROGRESSES INTO
THE LOWER GREAT LAKES REGION LATER TONIGHT.  THIS WILL OCCUR IN
RESPONSE TO EAST NORTHEASTWARD PROPAGATION OF A 100+ KT 500 MB JET
OUT OF THE SOUTH CENTRAL HIGH PLAINS.

IN WAKE OF THE LOW...COLD FRONT WILL SURGE SOUTHEAST OF THE MIDDLE
MISSISSIPPI VALLEY/OZARK PLATEAU REGION...WITH ASSOCIATED FORCING
PROVIDING FOCUS FOR EVOLUTION OF A SQUALL LINE BY EARLY EVENING. 
INITIATION OF THIS PROCESS ALREADY APPEARS UNDERWAY FROM PARTS OF
CENTRAL ILLINOIS THROUGH SOUTHWESTERN MISSOURI.

NARROW PLUME OF ELEVATED MIXED LAYER AIR...EMANATING FROM THE
SOUTHERN PLATEAU...EXTENDS AHEAD OF FRONT...ACROSS THE OZARK PLATEAU
INTO THE LOWER OHIO VALLEY.  THIS IS CONTRIBUTING TO A CORRIDOR OF
CONVECTIVE INSTABILITY WHICH WILL SUPPORT THE DEVELOPMENT OF SEVERE
THUNDERSTORMS. GIVEN BOUNDARY LAYER DEW POINTS IN THE MID/UPPER
50S...AS FORCING WEAKENS MID-LEVEL INHIBITION LATE THIS
AFTERNOON...CAPE APPEARS LIKELY TO EXCEED 500 J/KG.  WITH DEEP LAYER
SHEAR ALREADY VERY STRONG AND SUPPORTIVE OF SUPERCELLS...LOW-LEVEL
HODOGRAPHS ALONG STRENGTHENING PRE-FRONTAL SOUTHERLY LOW-LEVEL JET
AXIS WILL BECOME INCREASINGLY FAVORABLE FOR TORNADOES.

JUXTAPOSITION OF STRONGER SHEAR/BOUNDARY LAYER BASED INSTABILITY
SUGGESTS BEST POTENTIAL FOR TORNADOES MAY EXIST FROM PARTS OF
NORTHERN ARKANSAS/SOUTHEAST MISSOURI INTO SOUTHERN ILLINOIS. 
HOWEVER...DESPITE SOMEWHAT WEAKER INSTABILITY IN CLOSER PROXIMITY TO
SURFACE LOW...AMBIENT VERTICAL VORTICITY AND STRONG FORCING FOR
UPWARD VERTICAL MOTION WILL CONTRIBUTE TO TORNADO POTENTIAL FARTHER
NORTH...INTO SOUTHERN PORTIONS OF THE GREAT LAKES REGION.  DAMAGING
WINDS/LARGE HAIL WILL ALSO LIKELY ACCOMPANY SQUALL LINE LATE THIS
AFTERNOON AND EARLY EVENING AS IT PROGRESSES INTO/THROUGH THE LOWER
OHIO VALLEY.

SURGING ARCTIC FRONT IS EXPECTED TO HAVE A GREATER TENDENCY TO
UNDERCUT SQUALL LINE BY THE MID/LATE EVENING HOURS.  THIS WILL
CONTRIBUTE TO A DIMINISHING SEVERE THREAT...AND MAY OCCUR FAIRLY
RAPIDLY DURING THE 17/03-06Z TIME FRAME.  AS MID/UPPER RIDGING
BUILDS INTO THE SOUTH CENTRAL STATES...STRONGER MID/UPPER FORCING
WILL CONTINUE RAPIDLY EASTWARD AHEAD OF SHORT WAVE TROUGH INTO THE
LOWER GREAT LAKES REGION OVERNIGHT.  AS THIS BECOMES INCREASING
CUT-OFF FROM GULF MOISTURE...THUNDERSTORM ACTIVITY WILL DIMINISH.
...LIKELY BY 12Z FRIDAY.

..KERR.. 02/16/2006

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT WERE
DISCONTINUED ON 14 FEBRUARY 2006 AND ARE NOW AVAILABLE
IN THE FOLLOWING PRODUCTS:

   WMO HEADER:       AWIPS ID:
   WUUS01            PTSDY1
   WUUS02            PTSDY2
   WUUS03            PTSDY3

A SERVICE CHANGE NOTICE ...SCN05-39... PROVIDES DETAILS
ON THIS TRANSITION. FOR ADDITIONAL DETAILS SEE THE FOLLOWING
WEB ADDRESS USING LOWER CASE LETTERS:
WWW.NWS.NOAA.GOV/OM/NOTIF.HTM