AREAS AFFECTED...PARTS OF CENTRAL/ERN MO...SERN IA...AND WRN/CENTRAL
AND NRN IL
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 171347Z - 171515Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...TSTMS ARE EXPECTED TO DEVELOP SWD FROM CENTRAL/ERN IA INTO
NRN/CENTRAL MO BY MID-LATE MORNING WITH ACTIVITY THEN MOVING QUICKLY
EWD INTO MUCH OF IL THROUGH THIS AFTERNOON. STORMS WILL BECOME
ORGANIZED WITH THE POTENTIAL TO EVOLVE INTO LONG-LIVED DISCRETE TO
SEMI-DISCRETE SUPERCELLS. THREATS FOR TORNADOES...HAIL AND DAMAGING
WINDS WITH THESE INITIAL STORMS SUGGEST A TORNADO WATCH MAY NEED TO
BE ISSUED BY MID-LATE MORNING.
DISCUSSION...MORNING VISIBLE SATELLITE IMAGERY SHOWED CONVECTIVE
CLOUDS ALONG A PRE-FRONTAL CONVERGENCE ZONE EXTENDING FROM SWRN-NERN
MO INTO SERN IA NEAR THE SURFACE LOW. MEANWHILE...RADAR IMAGERY
SHOWED A NARROW BAND OF REFLECTIVITY EXTENDING FROM SWRN IA INTO
NWRN MO /INVOF KANSAS CITY MO/...WITH THIS LIKELY INDICATING THE
PRESENCE OF THE COLD FRONT AND STRONG DEEP LAYER FORCING FOR ASCENT
ADVANCING EWD INTO THIS REGION. STORMS...MAINLY ELEVATED...ARE
ONGOING OVER CENTRAL/ERN IA ALONG AND N OF A BOUNDARY EXTENDING FROM
SWRN-NERN IA.
THE DEGREE OF FORCING ADVANCING EWD ACROSS THE DISCUSSION AREA
COMBINED WITH STRONG DEEP LAYER AND LOW LEVEL SHEAR ALREADY PRESENT
OVER MO/IL /E.G. 0-1 KM BULK SHEAR NEAR 50 KT/ IS EXPECTED TO
SUPPORT TSTM DEVELOPMENT SWD FROM CENTRAL/ERN IA INTO NRN/CENTRAL MO
AS LOW LEVEL CONVERGENCE INCREASES WITH THE COLD FRONT OVERTAKING
THE PRE-FRONTAL TROUGH.
..PETERS/CORFIDI.. 11/17/2013
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...LSX...DVN...SGF...DMX...EAX...
LAT...LON 38589247 39839289 41419214 42039044 42258924 42138769
40058797 38328946 37929044 37869177 38589247
