DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 170103
SWODY1
SPC AC 170100

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0700 PM CST SAT NOV 16 2013

VALID 170100Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID TO
UPPER MS VALLEY...

...MID TO UPPER MS VALLEY...
AN IMPRESSIVE UPPER-LEVEL SYSTEM WILL MOVE INTO THE HIGH PLAINS
TONIGHT AS A 80 TO 100 KT MID-LEVEL JET TRANSLATES EWD THROUGH THE
BASE OF AN UPPER-LEVEL TROUGH OVER THE CNTRL GREAT PLAINS. AHEAD OF
THE SYSTEM...A BROAD 50 TO 60 KT LOW-LEVEL JET FROM THE OZARKS NEWD
INTO THE GREAT LAKES WILL GRADUALLY STRENGTHEN. SCATTERED
THUNDERSTORMS ARE CURRENTLY DEVELOPING ON THE WRN EDGE OF THE
LOW-LEVEL JET ACROSS ERN KS AND NW MO. THIS ACTIVITY SHOULD
GRADUALLY INCREASE AND MOVE EWD TOWARD THE MS VALLEY THIS EVENING.
THE LATEST OBJECTIVE ANALYSIS SHOWS AN AXIS OF INSTABILITY WITH
MLCAPE AROUND 500 J/KG EXTENDING FROM SE KS INTO SE IA. THE NAM
MODEL STEADILY INCREASES INSTABILITY AND LOW-LEVEL MOISTURE ACROSS
MO TONIGHT SUGGESTING THE POTENTIAL FOR SEVERE STORMS SHOULD
CONTINUE AND SHOULD SPREAD NEWD WITH TIME. THE 00Z SOUNDING AT
KANSAS CITY STILL SHOWS A STRONG LOW-LEVEL INVERSION SUGGESTING THE
ACTIVITY REMAINS ELEVATED. THIS FACTOR COMBINED WITH STRONG DEEP
LAYER SHEAR AND MID-LEVEL LAPSE RATE AROUND 7.5 C/KM ON THE
SPRINGFIELD MO 00Z SOUNDING MAY MAKE THE INITIAL THREAT WITH
SUPERCELLS LARGE HAIL. HOWEVER...OBJECTIVE ANALYSIS SHOWS A WEAKNESS
IN THE INVERSION OVER NCNTRL MO SUGGESTING THE ACTIVITY MAY BECOME
MORE SFC-BASED LATE THIS EVENING AS IT MOVES FURTHER TO THE EAST
NORTHEAST. THIS MAY HELP A WIND DAMAGE THREAT TO DEVELOP LATER THIS
EVENING PERSISTING INTO THE OVERNIGHT PERIOD. ALTHOUGH SFC DEWPOINTS
ARE ONLY IN THE MID 50S F ACROSS WRN IL AND SERN IA...RAPID MOISTURE
ADVECTION AND DESTABILIZATION MAY BE ENOUGH FOR A TORNADO THREAT
WITH THE MORE DOMINANT CELLS LATE TONIGHT.

FURTHER TO THE SOUTH SOUTHEAST...THE CAP IS FORECAST TO WEAKEN ALONG
THE MS RIVER LATE THIS EVENING INTO THE OVERNIGHT PERIOD. THIS
SHOULD ALLOW NEW CONVECTION TO INITIATE WITH STORMS INCREASING IN
COVERAGE DURING THE OVERNIGHT PERIOD. RAPID LOW-LEVEL MOISTENING AND
STRENGTHENING DEEP LAYER SHEAR ACROSS SRN IL AND SERN MO SHOULD ALSO
BE SUFFICIENT FOR A SEVERE THREAT IN THE MID MS VALLEY. NAM FORECAST
SOUNDINGS IN SE MO AT 09Z TO 12Z SHOW SFC DEWPOINTS IN THE LOWER TO
MID 60S F...MLCAPE OF 1000 TO 1200 J/KG WITH 50 KT OF DEEP LAYER
SHEAR. THIS SHOULD BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL AND
ISOLATED WIND DAMAGE. DUE TO THE LARGE LOOPED HODOGRAPHS AND
POTENTIAL FOR SFC-BASED DEVELOPMENT...A THREAT FOR TORNADOES CAN NOT
BE RULED OUT. FOR THIS REASON...WILL EXTEND THE SLIGHT RISK AREA SWD
ACROSS SE MO AND SCNTRL IL INTO FAR NE AR AND WRN KY. WILL ALSO ADD
A SMALL 5 PERCENT TORNADO PROBABILITY SWD ALONG THE MS RIVER IN SRN
IL...SE MO AND WRN KY.

..BROYLES.. 11/17/2013

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