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000
FXUS63 KILX 180202
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
902 PM CDT MON JUN 17 2013

.DISCUSSION...
ISSUED 902 PM CDT MON JUN 17 2013

CURRENT FORECAST LOOKS OK BUT MAY NEED TO TWEAK THE ISOLATED
THUNDERSTORMS IN THE NORTH AND EXTENDED IT A FEW MORE HOURS...TIL
MIDNIGHT. THEN ISOLATED SHOWERS/THUNDERSTORMS WILL BE ACROSS THE
CENTRAL AND SOUTHEAST AFTER MIDNIGHT. REMAINDER OF THE FORECAST
LOOKS FINE WITH TEMPS FALLING INTO THE LOWER TO MIDDLE 60S BY
MORNING...WITH LIGHT WINDS AND MOSTLY CLEAR SKIES. SO WILL BE
MAKING SOME MINOR ADJUSTMENTS TO THE FORECAST. UPDATE WILL BE OUT
SHORTLY.

AUTEN
&&

.AVIATION...
ISSUED 634 PM CDT MON JUN 17 2013

ALL TAF SITES WILL START WITH HIGH CIRRUS THIS EVENING. AS THE
SYSTEM DOWN OVER SOUTHERN IL MOVES EAST THE CLOUDS WILL SCATTER
OUT LATER TONIGHT AND OVERNIGHT. HOWEVER...WITH MOSTLY CLEAR SKIES
AND LIGHT WINDS AGAIN...WILL PROBABLY SEE SOME LIGHT FOG AGAIN.
NOT EXPECTING VIS TO GO AS LOW AS IT DID LAST NIGHT. SO WILL KEEP
VIS AT LOWER MVFR LEVELS. THEN CONDITIONS WILL IMPROVE DURING THE
MORNING HOURS WITH SCATTERED CU EXPECTED. THEN ANOTHER SYSTEM WILL
DROP SOUTHEAST TOWARD THE AREA IN THE AFTERNOON. ALL MODELS HAVE
SOME LIGHT QPF ACROSS THE AREA TUE AFTERNOON SO WILL GO AHEAD AND
HAVE VCTS FOR ALL TAF SITES FOR AFTERNOON TIME FRAME. WINDS WILL
BE LIGHT AND VARIABLE OVERNIGHT AND EARLY TOMORROW...THEN BECOME
MORE NORTH TO NORTHEAST DURING THE DAY AND IN THE AFTERNOON.

AUTEN
&&

.PREV DISCUSSION...
ISSUED 220 PM CDT MON JUN 17 2013

SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT

MAIN CONCERNS THIS PERIOD WILL BE WITH COVERAGE OF PRECIP ACRS OUR
SOUTHERN COUNTIES TONIGHT...ASSOCIATED WITH AN MCV OVER MISSOURI...
AND WITH A WEAK SURFACE BOUNDARY FORECAST TO EDGE INTO OUR AREA
TUESDAY AFTERNOON. AFTER THAT...SOMEWHAT COOLER AND LESS HUMID WEATHER
WILL FOLLOW INTO THURSDAY BEFORE HEAT BUILDS NORTHWARD INTO THE REGION
FOR THE END OF THE WEEK AND NEXT WEEKEND.

WATER VAPOR LOOP SHOWING THE CONVECTIVE COMPLEX FROM LAST NIGHT
PRODUCING A DISTINCT MCV OVER PARTS OF WESTERN MO WITH NEW CONVECTION
DEVELOPING TO ITS EAST INTO EAST CENTRAL AND SE MO AND TRYING TO
DEVELOP A BIT FURTHER NORTH INTO SOUTHERN ILLINOIS. LOOKING NORTH...
SEVERAL LOW AMPLITUDE SHORTWAVES TRACKING E-SE ACRS THE NORTHERN
PLAINS. ONCE SUCH WAVE PUSHING ACRS WISCONSIN WITH A WEAK SFC BOUNDARY
SHIFTING SOUTH DOWN LAKE MICHIGAN...WHICH SHORT TERM MODELS SUGGEST
WILL PUSH ACRS EXTREME SOUTHERN LAKE MICHIGAN LATER THIS EVENING.
THE AIR MASS AHEAD OF THIS FEATURE NOT PARTICULARLY CONDUCIVE TO
WIDESPREAD CONVECTION DEVELOPING AHEAD OF IT SO OTHER THAN SOME
SLIGHT CHANCE (ISOLATED WORDING) FOR THIS EVENING ACRS THE FAR
NORTH...IT STILL APPEARS THE BETTER PROBABILITIES FOR EVENING
CONVECTION WILL BE TIED TO THE MISSOURI MCV AS IT TRACKS ESE WELL
TO OUR SOUTH.

THE NORTHERN STREAM WAVE ACRS NORTH DAKOTA LOOKS A BIT MORE IMPRESSIVE
THAN WHAT MODELS WERE DEPICTING AT THIS TIME YESTERDAY. MODELS CONTINUE
TO BRING THIS WAVE ESE INTO THE LAKES REGION TUESDAY AFTERNOON WITH
A WEAK COLD FRONT EDGING SOUTH INTO OUR AREA. CONVERGENCE ALONG THE
BOUNDARY IS NOT VERY IMPRESSIVE AT ALL BUT WITH THE TIMING OF THE
BOUNDARY INTO OUR AREA DURING PEAK HEATING...IT STILL WARRANTS SLIGHT
CHANCE (ISOLATED COVERAGE) FOR TUESDAY AFTERNOON. SOMEWHAT COOLER AND
LESS HUMID AIR WILL FILTER SOUTH ACRS THE AREA IN THE WAKE OF THE
SHORTWAVE TUESDAY NIGHT INTO WEDNESDAY BRINGING QUIET AND PLEASANT
WEATHER FOR THE REMAINDER OF THE SHORT TERM PERIOD.

LONG TERM...FRIDAY THROUGH MONDAY

LONGER RANGE MODELS...AT LEAST THE GFS AND UK...WERE MUCH MORE
AGGRESSIVE WITH THE RETROGRESSION OF THE SUBTROPICAL RIDGE ACRS
THE CENTRAL U.S...TAKING THE STRONGER 500 MB FLOW FURTHER NORTH
AWAY FROM OUR AREA. THE 12Z ECMWF NOT NEARLY AS STRONG WITH THE
UPPER RIDGE AS IT TAKES A SERIES OF SHORTWAVES FROM THE LONGWAVE
TROF ACRS THE PACIFIC NW AND TEMPORARILY FLATTENS THE RIDGE AXIS
TO OUR WEST...KEEPING THE AMPLITUDE MUCH FLATTER OVER THE LOWER
48...WHICH GIVES OUR AREA A BETTER CHANCE FOR SEEING SCATTERED
CONVECTION...ESPECIALLY ACRS THE NORTH DURING THE WEEKEND. LOOKS
AS IF THE GFS SOLUTION MAY BE OVERDONE...COMPARED TO WHAT IT WAS
SHOWING THE PAST SEVERAL RUNS. SO FAR THIS SPRING...THE SHORTWAVES
EJECTING ENE FROM THE WESTERN U.S. TROFS AND THEIR ASSOCIATED
CONVECTION HAVE BEEN SUCCESSFUL IN KEEPING THE AMPLITUDE OF THE
RIDGE ACRS THE CENTRAL PORTION OF THE COUNTRY FLATTER. WILL TEND
TO SIDE MORE WITH THE ECMWF THIS PERIOD BUT IT WON`T MAKE MUCH OF
A DIFFERENCE IN THE EXTENDED PORTION OF THE FORECAST WITH HOT
WEATHER RETURNING FOR THE WEEKEND AND THE HIGHER RAIN CHANCES ACRS
THE NORTH.

SMITH

&&

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

$$