000
FXUS63 KILX 201602
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1002 AM CST THU NOV 20 2008
.DISCUSSION...
ISSUED 1000 AM CST THU NOV 20 2008
FORECAST AGAIN LOOKS ON TRACK TODAY AND ONLY DID MINOR TWEAKS TO
THE HOURLY TEMPERATURE...DEWPOINT AND SKY GRIDS. MOSTLY CLOUDY TO
OVERCAST SKIES TODAY WITH BRISK NORTHWEST WINDS 10 TO 20 MPH AND
GUSTS IN THE 20S. MUCH COOLER HIGHS IN THE MID TO UPPER 30S.
LATE MORNING SURFACE MAP SHOWS STRONG 1049 MB CANADIAN HIGH
PRESSURE ALONG THE SASKETCHEWAN AND MANITOBA LINE AND RIDGING
SOUTHWARD ACROSS THE HIGH PLAINS. THIS STRONG HIGH PRESSURE HAS
PUSHED THE COLD FRONT WELL SOUTH OF IL TO ALONG THE SOUTHERN TN
BORDER. NEARLY OVERCAST STRATOCUMULUS CLOUD DECK COVERS IL WITH
CEILINGS AROUND 4K FT. TEMPERATURES WERE MOSTLY IN THE MID 30S BUT
RANGED FROM 32F IN BLOOMINGTON TO 38F IN LAWRENCEVILLE. NNW WINDS
10 TO 15 MPH WITH GUSTS OF 18 TO 25 MPH WERE PRODUCING WIND CHILLS
IN THE 20S. ALOFT A LARGE UPPER LEVEL LOW/TROF WAS OVER EASTERN
CANADA AND COVERING THE NE HALF OF THE U.S. WHILE UPPER LEVEL
RIDGE WAS OVER THE ROCKIES. IL REMAINS IN A NW UPPER LEVEL FLOW.
SHORT WAVE WAS PUSHING SOUTHWARD ACROSS MN/WI TOWARD THE NORTHERN
IA/IL BORDER.
12Z RUC...NAM AND SREF MODELS ARE SIMILAR IN TRACKING A SHORT WAVE
SOUTHWARD ACROSS CENTRAL IL DURING THIS AFTERNOON AND SE IL EARLY
THIS EVENING. LIMITED MOISTURE WITH THIS FEATURE SO JUST EXPECTING
SCATTERED FLURRIES THIS AFTERNOON AND EARLY EVENING. LOW CLOUDS
WILL DECREASE FROM THE WEST DURING TONIGHT AS STRONG CANADIAN HIGH
PRESSURE DRIFTS EAST TOWARD THE MS VALLEY BY FRI MORNING. WILL BE
A COLD NIGHT TONIGHT WITH LOWS IN THE MID TO UPPER TEENS. BRISK NW
WINDS COMBINED WITH LOW CLOUDS WILL LIMIT HEATING TODAY WITH
TEMPERATURES NOT CLIMBING MUCH MORE THAN A DEGREE OR TWO. HIGHS IN
THE MID 30S OVER CENTRAL IL AND UPPER 30S IN SE IL WITH
LAWRENCEVILLE NEAR 40F.
HUETTL
&&
.AVIATION...
ISSUED 504 AM CST THU NOV 20 2008
CLOUDY SKIES WILL PREVAIL AT ALL TAF SITES FOR MOST OF THE DAY.
POSITIVE SIDE IS CIG HEIGHTS WILL BE ABOVE 3KFT. SO VFR CIGS IS
EXPECTED THROUGHOUT THE DAY. MODEL TRENDS ARE FOR CLOUDS TO BEGIN
TO THIN OUT AND BECOME MORE SCATTERED EARLY THIS EVENING...AND
THEN BECOME MOSTLY CLEAR TONIGHT. THIS APPEARS REASONABLE AND WILL
FOLLOW THIS TREND IN NEW TAFS. WINDS WILL BE NORTHWESTERLY NEXT
24HRS AND COULD BE TAD GUSTY DURING THE DAYLIGHT HOURS.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 307 AM CST THU NOV 20 2008
COLD FRONT PUSHED THROUGH THE SOUTHEAST CWA EARLY LAST EVENING AND
WAS NOW CENTERED CLOSE TO THE OHIO RIVER. STRATOCUMULUS DECK WAS
LAGGING BEHIND A BIT...BUT NOW COVERED THE NORTHWEST 2/3 OF THE
CWA. WATER VAPOR IMAGERY SHOWED THE NEXT IN THE SHORTWAVE SERIES
APPROACHING NORTHWEST NORTH DAKOTA.
ISSUES OF THE DAY INCLUDE SKY COVER FOR TODAY...AND THE EFFECTS OF
THE SUNDAY/MONDAY STORM SYSTEM OVER THE FORECAST AREA.
SHORT TERM...TODAY THROUGH SATURDAY...
SHORTWAVE TO QUICKLY MOVE SOUTHEAST ACROSS THE CWA THIS AFTERNOON
AND EVENING. WITH DRIER LOW LEVELS...DO NOT EXPECT MUCH MORE THAN
FLURRIES FROM THIS FEATURE. CLOUDS WILL BE SLOWER TO ERODE
THOUGH...AS INVERSION TIGHTENS AROUND 850 MB. MUCH OF THE DAY
EXPECTED TO BE CLOUDY...WITH SOME SLOW IMPROVEMENT TOWARD LATE
AFTERNOON. MORE RAPID CLEARING EXPECTED DURING THE EVENING HOURS.
CANADIAN HIGH PRESSURE TO BUILD SOUTH THE NEXT 24 HOURS...AND
SHOULD BE CENTERED IN MISSOURI BY MIDDAY FRIDAY AND ACROSS THE
TENNESSEE VALLEY FRIDAY NIGHT. THIS WILL PROVIDE A CHALLENGE TO A
SHORTWAVE WHICH WILL DIVE SOUTHEAST OUT THE NORTHERN ROCKIES. THIS
FEATURE IS EXPECTED TO WEAKEN AS IT MOVES OVER THE CWA...AND ANY
MEASURABLE PRECIPITATION SHOULD REMAIN TO OUR NORTHWEST. DID ADD A
FEW FLURRIES FOR AREAS WEST OF I-55 DURING THE MORNING.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH CUTOFF UPPER LOW
WHICH WILL MOVE INTO THE GREAT LAKES REGION EARLY NEXT WEEK.
ASSOCIATED SURFACE COLD FRONT EXPECTED TO MOVE ACROSS ILLINOIS
SUNDAY NIGHT. REMOVED RAIN CHANCES SUNDAY MORNING AND CONVERTED
THE AFTERNOON TO SILENT 20 POPS...AS THE AIR WILL BE QUITE DRY
INITIALLY AND IT WILL TAKE MUCH OF THE DAY TO GET SUFFICIENTLY
MOIST. SHOULD BE A FAIR AMOUNT OF SUNSHINE EVEN...ESPECIALLY IN
THE MORNING BEFORE HIGH CLOUDS ARRIVE AND THICKEN. ONCE
PRECIPITATION FORMS DURING THE EVENING...IT SHOULD BE RATHER LIGHT
AND MAINLY ACROSS THE EASTERN CWA. MODEL SOUNDINGS SHOW MUCH OF
THIS TO BE RAIN. MAY SEE SOME WRAPAROUND FLURRIES LATER MONDAY
THOUGH.
CUTOFF LOW TO BE SLOW TO PUSH EAST ACROSS THE REGION THROUGH
MIDWEEK. DID NOT MAKE ANY CHANGES IN THE FORECAST AT THAT TIME
RANGE THOUGH.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
