Area Forecast Discussion
Issued by NWS Central Illinois

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KILX 040826
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
326 AM CDT SAT JUL 4 2015

.SHORT TERM...(TODAY)
ISSUED AT 326 AM CDT SAT JUL 4 2015

07Z/2AM SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY SOUTH OF THE OHIO
RIVER...WHILE WEAK HIGH PRESSURE IS CENTERED OVER EASTERN NEBRASKA.
AS THE HIGH SHIFTS SLOWLY EASTWARD...MOSTLY SUNNY SKIES AND LIGHT
WINDS WILL BE THE RULE ACROSS CENTRAL ILLINOIS TODAY.  FORECAST
SOUNDINGS INDICATE MIXING UP TO ABOUT 875MB...RESULTING IN AFTERNOON
HIGH TEMPERATURES IN THE LOWER TO MIDDLE 80S.  DESPITE THE WARMER
CONDITIONS...DEWPOINTS WILL REMAIN FAIRLY TOLERABLE IN THE 60-65
DEGREE RANGE.

&&

.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 326 AM CDT SAT JUL 4 2015

ONCE THE HIGH SHIFTS FURTHER EAST...AN INCREASING SOUTHERLY RETURN
FLOW WILL BRING EVEN WARMER AND MORE HUMID AIR INTO THE REGION
SUNDAY AND MONDAY.  HIGH TEMPERATURES WILL REACH THE MIDDLE TO UPPER
80S BOTH DAYS...WHILE DEWPOINTS CLIMB OVER 70 DEGREES.

SHORT-WAVE TROUGH CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER
NORTHERN BRITISH COLUMBIA WILL DROP SOUTHEASTWARD OVER THE NEXT
COUPLE OF DAYS...TRIGGERING SURFACE CYCLOGENESIS IN THE LEE OF THE
ROCKIES ACROSS WESTERN KANSAS ON SUNDAY.  THE LOW WILL THEN TRACK
INTO SOUTHERN MINNESOTA BY 12Z MONDAY THEN TO LAKE SUPERIOR BY 00Z
TUE.  AS IT DOES...IT WILL DRAG A COLD FRONT TOWARD CENTRAL ILLINOIS
BY LATE MONDAY.  MODELS CONTINUE TO DELAY THE FRONT...WITH THE 00Z
JULY 4 RUNS NOW KEEPING IT WEST OF THE MISSISSIPPI RIVER UNTIL
MONDAY NIGHT.  WHILE ATMOSPHERE AHEAD OF THE BOUNDARY WILL BECOME
HIGHLY UNSTABLE WITH SBCAPE VALUES IN EXCESS OF 3000J/KG MONDAY
AFTERNOON...SYNOPTIC FORCING WILL BE ABSENT AND 0-6KM SHEAR WILL
REMAIN QUITE MEAGER AT JUST 15-20KT.  AM THEREFORE EXPECTING A
LARGELY HOT AND DRY DAY...WITH PERHAPS A FEW THUNDERSTORMS ARRIVING
IN THE ILLINOIS RIVER VALLEY AHEAD OF THE FRONT BY LATE AFTERNOON.
HAVE CUT BACK POPS ACCORDINGLY.  AS THE FRONT PUSHES INTO THE
AREA...SHOWERS AND THUNDERSTORMS WILL BECOME WIDESPREAD MONDAY NIGHT
INTO TUESDAY.

AS THE FRONT BECOMES PARALLEL TO THE ZONAL UPPER-LEVEL FLOW...IT
WILL EVENTUALLY BECOME STALLED ACROSS SOUTHERN ILLINOIS BY TUESDAY
NIGHT.  BASED ON GFS/ECMWF/GEM CONSENSUS...THINK BOUNDARY WILL SLIP
FAR ENOUGH SOUTH TO END RAIN CHANCES ALONG/NORTH OF A CANTON TO
BLOOMINGTON LINE TUESDAY NIGHT AND WEDNESDAY.  FURTHER SOUTH...WILL
CONTINUE POPS AS A WEAK WAVE RIPPLES ALONG THE BOUNDARY.  ONCE THIS
FEATURE PASSES TO THE EAST...ECMWF SHOWS FRONT GETTING SHUNTED
FURTHER SOUTHWARD AND SHORT-WAVE RIDGING ARRIVING WEDNESDAY NIGHT
AND THURSDAY.  WILL GO WITH A LARGELY DRY FORECAST DURING THAT TIME
ACCORDINGLY.  AFTER THAT...RAIN CHANCES WILL RETURN FOR THE END OF
THE WEEK AS UPPER HEIGHTS BUILD AND FRONT GETS PUSHED BACK NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1105 PM CDT FRI JUL 3 2015

LITTLE CHANGE IN THINKING FROM THE PREVIOUS AVIATION DISCUSSION.
THE MAIN CONCERN THIS PERIOD WILL BE IN THE 09Z-13Z TIME FRAME FOR
THE POTENTIAL FOR SOME MVFR VSBYS IN FOG. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THRU 06Z SATURDAY. WEAK HIGH PRESSURE WILL
DRIFT OVER THE AREA OVER THE NEXT 12 TO 18 HOURS BRINGING LIGHT
WINDS TO ALL OF THE TAF SITES. ANY FOG WE DO SEE EARLY SATURDAY
MORNING WILL QUICKLY DISSIPATE WITH SOME SCATTERED CUMULUS FORMING
WITH BASES IN THE 3000-4000 FOOT LEVEL BY EARLY AFTERNOON. SURFACE
WINDS ARE EXPECTED TO BE LIGHT AND VARIABLE THRU MOST OF THIS
FORECAST PERIOD.


&&

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

$$

SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.