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000
FXUS63 KILX 182009
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
309 PM CDT SAT MAY 18 2013

.DISCUSSION...
ISSUED 250 PM CDT SAT MAY 18 2013
UPPER TROF DIGGING IN OVER ROCKY MTNS THE START OF A DEVELOPING
LOW PRESSURE STORM SYSTEM THAT WILL KEEP CENTRAL AND SOUTHEASTERN
ILLINOIS IN RAIN CHANCES THROUGH MID WEEK. FOR NOW...QUASI
STATIONARY BOUNDARY TO THE NORTH AND PLENTY OF WARM AIR OVER THE
REGION...WITH 11C-12C AT 850 AND PARTLY CLOUDY SKIES. TEMPS AT MID
LEVELS ON THE RISE FOR THE NEXT COUPLE OF DAYS AS THAT SFC LOW
GETS A LITTLE DEEPER AND SOUTHERLY FLOW AHEAD OF IT ANCHORS MUCH
OF IL FIRMLY IN THE WARM SECTOR. QUASI STATIONARY BOUNDARY MAY
DRIFT A BIT WITH MESOSCALE INFLUENCE OF ANY TS THAT MAY
DEVELOP...BUT FOR THE MOST PART...SEVERE THREAT FOR TOMORROW
CONFINED TO WEST/NW CLOSER TO THE LOW ITSELF. FOR MONDAY...THREAT
MORE WIDESPREAD AS THE LOW IS SLOW TO PROGRESS OUT OF THE MIDWEST.

SHORT TERM...TONIGHT THROUGH TOMORROW...
SOUTHERLY FLOW AND VERY WARM TEMPS TOMORROW...UPPER 80S AND CLOSE
TO 90 AS THE 850MB TEMPS RISE TO 16-17C. HEAT FOR THE NW GOING TO
BE INFLUENCED BY ANY TS/OUTFLOW/AFTERNOON DEVELOPMENT OF PRECIP.
THOUGH THERE IS A CHANCE FOR TS IN THE AFTERNOON NW OF THE
ILLINOIS RIVER VALLEY...THE MAJORITY OF THE THREAT WILL BE AFTER
00Z TOMORROW EVENING. HOWEVER...MUCH OF THIS IS BASED ON THE
SLOWER GFS SOLUTION WITH THE STORM GENESIS TO THE SW. MODERATE
RISK IN THE SW...WITH MUCH OF THE SEVERE ACTIVITY HERE BEING LESS
WIDESPREAD IN NATURE...AND MODIFIED A BIT AS IT MOVES FURTHER
AWAY FROM THE UPPER LEVEL SUPPORT/DRYLINE/MID LEVEL JET MAX THAT
IS FAR SUPERIOR IN THE SW.

LONG TERM...MONDAY THROUGH FRIDAY...
AS THE UPPER LOW DRIFTS CLOSER TO THE REGION...CHANCES FOR PRECIP
AND SEVERE WEATHER SPREAD TO ENTIRE CWA FOR MONDAY. TS CHANCES
BEST IN THE AFTERNOON...AND WIND AND HAIL ARE THE MAIN
THREATS...THOUGH MUCH OF THAT HINGES ON THE AVAILABLE INSTABILITY
AND LOCATION OF MID LEVEL WIND MAX. RAIN/TS CHANCES CONTINUE
THROUGH WED EVENING AS A COLD FRONT SLOWLY PROGRESSES
THROUGH THE REGION TUES NIGHT/WED MORNING. UPPER LOW SLOWLY GETS
OUT OF HERE THUR/FRI. AND THOUGH GFS/ECMWF TRYING TO SPIN UP SOME
WEAK SHOWERS...LEAVING THEM OUT FOR NOW AS REGION WILL BE UNDER A
BUILDING HIGH BRIEFLY AS ANOTHER LOW DIGS IN OVER THE WEST COAST
LATE THUR.

HJS
&&

.AVIATION...
ISSUED 1214 PM CDT SAT MAY 18 2013

HAVE SEEN SOME BRIEF MVFR CEILINGS THE LAST COUPLE HOURS AS
CUMULUS FIELD INCREASED...BUT CEILINGS ARE STEADILY LIFTING TO
AROUND 5000 FEET AND WILL NOT MENTION ANY MVFR CONDITIONS THIS
AFTERNOON. CANNOT RULE OUT A STRAY SHOWER AROUND KCMI...BUT
CHANCES ARE TOO REMOTE TO INCLUDE IN THE TAF AT THIS TIME. CLOUDS
EXPECTED TO FADE OUT BY SUNSET. MAY SEE SOME LIGHT FOG LATER IN
THE NIGHT SIMILAR TO THIS MORNING...BUT INCREASING WINDS AFTER 06Z
SHOULD KEEP VISIBILITIES FROM GETTING OUT OF HAND. HAVE MAINTAINED
THE TEMPO PERIODS FOR VISIBILITIES AROUND 2 TO 3 MILES...BUT
EXPANDED THEM TO ABOUT A 4 HOUR WINDOW.

GEELHART
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$