[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 181617
SWODY1
SPC AC 181615

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1115 AM CDT SUN JUN 18 2006

VALID 181630Z - 191200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM LOWER OH TO WRN TN
VALLEYS...

...THERE IS A SLGT RISK OF SVR TSTMS ERN NEB INTO WRN IA...

...CENTRAL U.S...
MID LEVEL TROUGH OVER MO WILL ACCELERATE EWD INTO OH VALLEY TODAY AS
STRONGER SYSTEM UPSTREAM DROPS ESEWD ACROSS UPR MS VALLEY. SEVERE
THUNDERSTORM CONCERNS TODAY WILL BE MODULATED BY EXTENSIVE
CLOUDINESS/PCPN AND GENERALLY WEAK LAPSE RATES CURRENTLY BEING
OBSERVED AHEAD OF MO TROUGH. 

DEEP LAYER SHEAR RANGES DOWNWARD FROM 30-40KT ACROSS MI TO GENERALLY
25KT OR LESS WRN TN VALLEY BY THIS AFTERNOON.  DRIER AIR NOTED ON
W/V IMAGERY ROTATING EWD ACROSS MO INTO LOWER OH VALLEY THIS
AFTERNOON SUGGESTS SUFFICIENT HEATING CAN OCCUR AHEAD OF TROUGH FOR
MDT INSTABILITY TO DEVELOP.

PLUME OF 70F PLUS DEWPOINTS THAT EXTENDS NNEWD LOWER MS VALLEY INTO
LOWER OH VALLEY.  WITH SURFACE TEMPS RISING THRU THE MID
80S...MLCAPE COULD CLIMB TO 2000 J/KG VICINITY CONFLUENCE OF OH AND
MS RIVERS.

GIVEN THE WEAK LAPSE RATES...GENERALLY LESS THAN 6C/KM AND ONLY
MODEST SHEAR...SURFACE BASED STORMS THAT DEVELOP BY MID-AFTERNOON
FROM LOWER OH TO WRN TN VALLEY EXPECTED TO BE PRIMARILY MULTICELL. 
WIND DAMAGE IN THE FORM OF WET DOWNBURSTS EXPECTED TO BE THE
DOMINANT THREAT AS THERMODYNAMICS DO NOT SUPPORT LARGE HAIL. 
ISOLATED BRIEF TORNADOES ARE ALSO POSSIBLE AS THE LFC'S SHOULD BE
LESS THAN 1500M WITH SOME HELICITY IN THE LOWER PORTION OF THE
HODOGRAPH.


...NE/IA...
RATHER STEEP LAPSE RATES ARE SPREADING EWD ACROSS NRN PLAINS AS FAR
S AS NEB ASSOCIATED WITH THE S/WV TROUGH MOVING THRU UPPER MS
VALLEY.  ALTHOUGH MOISTURE HAS DECREASED WITH WLY FLOW ACROSS
PLAINS...THE STRONG HEATING...STEEP LAPSE RATES AND 40-50 KT OF DEEP
LAYER SHEAR SUPPORTS CONTINUING THE LOW END SLIGHT RISK CURRENTLY
ERN NE INTO IA BEGINNING LATER THIS AFTERNOON. STORMS THAT DEVELOP
WILL BE HIGH BASED WITH DCAPES IN EXCESS OF 1000 J/KG SUPPORTING
WIND DAMAGE THREAT.  WHILE LOW LEVEL FLOW IS RELATIVELY
WEAK...FAVORABLE SHEAR IN CLOUD BEARING LAYER DOES SUPPORT SUPERCELL
POTENTIAL ENHANCING LARGE HAIL THREAT. SURFACE BASED STORMS
EXPECTED TO DEVELOP BY LATE AFTERNOON ERN NEB WHERE  INHIBITION
WEAKENS AND MLCAPES CLIMB TO NEAR 1000 J/KG. STORMS SHOULD CONTINUE
E/SEWD INTO IA BY EARLY TONIGHT.

..HALES/GRAMS.. 06/18/2006