FXUS63 KILX 050844
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
244 AM CST SUN FEB 5 2012

.DISCUSSION...
ISSUED 240 AM CST SUN FEB 5 2012

UPPER LOW CONTINUES TO SPIN ACROSS THE CENTRAL U.S. EARLY THIS
MORNING...WITH WATER VAPOR IMAGERY SHOWING IT CENTERED NEAR KANSAS
CITY...WITH A SECOND LOW FURTHER WEST ACROSS UTAH. CLEARING LINE
HAS BEEN QUICKLY MOVING SOUTH ACROSS THE NORTHERN CWA THE LAST FEW
HOURS...AND WAS JUST SOUTH OF THE I-74 CORRIDOR AT 2 AM. INITIAL
FORECAST CHALLENGE WILL BE WITH CLEARING TREND AND FOG POTENTIAL
EARLY ON...AS CLOUDS BREAK IN AREAS THAT HAD DECENT RAINFALL THE
LAST 24-36 HOURS. HOWEVER...THE PRIMARY FORECAST ISSUE WILL BE
WITH TREND FOR COLD WEATHER TOWARD THE END OF THE WEEK.


SHORT TERM...TODAY THROUGH TUESDAY...

LATEST HRRR NOT TOO FAR OFF WITH CURRENT POSITIONING OF THE
STRATUS...AND SHOWS MUCH OF THE CWA SHOULD BE STRATUS-FREE BY LATE
MORNING. NORTHERN CWA IS MOST VULNERABLE FOR SOME FOG EARLY...WITH
LACON CURRENTLY REPORTING 3/4 MILE AND BLOOMINGTON 1-3/4 MILE AS
THE CLOUDS HAVE BROKEN. SO FAR NOTHING NORTH OF THERE IS GETTING
OUT OF HAND YET DESPITE A LONGER CLEAR PERIOD...SO WILL MAKE A
LAST MINUTE DECISION ON WHETHER TO CONTINUE FOG POTENTIAL BEYOND
SUNRISE.

MISSOURI UPPER LOW PROGGED TO DRIFT SOUTHEAST TO THE LOWER OHIO
VALLEY BY TONIGHT. ANY RESIDUAL LIGHT RAIN/DRIZZLE WILL CONTINUE
TO SHRINK WITH THIS LOW...AND WILL LIKELY ONLY MENTION IT IN THE
FAR SOUTHEAST FOR EARLY TODAY. SURFACE HIGH PRESSURE RIDGING
EASTWARD POSES ANOTHER CONCERN FOR LOW CLOUDS/FOG TONIGHT. LATEST
SREF GRAPHICS SHOWING THE NORTHWEST CWA BEING OVERSPREAD BY LOWER
STRATOCUMULUS AFTER MIDNIGHT...LASTING UNTIL ABOUT MID-MORNING
MONDAY. GIVEN THAT THIS AREA SHOULD SEE DECENT SUNSHINE MUCH OF
TODAY TO HELP DRY THINGS OUT...AM NOT OVERLY CONFIDENT IN THIS
CLOUD SCENARIO AT THE MOMENT. FOR NOW...WILL GO WITH PARTLY CLOUDY
CONDITIONS ACROSS THE NORTHWEST TONIGHT AND MAINLY CLEAR
ELSEWHERE...WITH THE DAY SHIFT MAKING ANY FURTHER ADJUSTMENTS AS
THE DAYTIME TRENDS PLAY OUT.

LEFTOVER CUTOFF ENERGY OVER THE CENTRAL ROCKIES SHOULD WEAKEN AND
GET PICKED UP BY A TROUGH MOVING ALONG THE CANADIAN BORDER MONDAY
NIGHT AND TUESDAY. NOT A LOT OF MOISTURE AVAILABLE OVERHEAD WHEN
IT ARRIVES...BUT SOME RESIDUAL MOISTURE ACCOMPANYING THE LEFTOVER
ENERGY IS ENOUGH TO WARRANT SLIGHT CHANCE POPS FOR TUESDAY AND
TUESDAY NIGHT.


LONG TERM...WEDNESDAY THROUGH SATURDAY...

QUIET WEATHER EXPECTED MIDWEEK AS HIGH PRESSURE DRIFTS ACROSS THE
MIDWEST. MAIN CONCERN REMAINS WITH THE AMOUNT OF ARCTIC AIR THAT
WILL BE DROPPING SOUTHEASTWARD LATE IN THE WEEK. GFS BRINGS 850 MB
TEMPERATURES OF -16C ACROSS MOST OF THE CWA BY FRIDAY EVENING...
WHILE ECMWF GIVES US MORE OF A GLANCING BLOW WITH THE CORE OF THE
COLDER AIR CLOSER TO THE GREAT LAKES. HAVE BEGUN TO TREND DOWNWARD
WITH THE TEMPERATURE FORECASTS AS THE MAIN IDEA HAS BEEN
PERSISTENT FOR A COUPLE DAYS NOW...BUT NOT AS AGGRESSIVELY AS THE
GFS WOULD INDICATE...WHICH GIVES THE NORTHERN CWA A STRUGGLE TO
REACH 20 DEGREES ON FRIDAY. THAT MAY BE TOUGH WITHOUT ANY SNOW ON
THE GROUND...BUT WE SHOULD STILL SEE SOMEWHAT OF A COLD SNAP IN
AN OTHERWISE MILD WINTER.

GEELHART

&&

.AVIATION...
ISSUED 1125 PM CST SAT FEB 4 2012

IFR CONDITIONS WILL CONTINUE AT SPI/DEC/CMI FOR A 2-3 MORE HOURS
AS THE LOWER CLOUDS WILL CONTINUE TO BE PUSHED SOUTH OVERNIGHT.
CMI SHOULD GO FIRST AROUND 08Z WITH SPI & DEC AT 09Z. THEN AC
CLOUDS AROUND 8KFT WILL DOMINATE THE AREA UNTIL THE MORNING HOURS.
PIA IS ALREADY THERE WITH VFR CONDITIONS WHILE BMI SHOULD BE
THERE AT TAF ISSUANCE TIME...THOUGH WITH SOME LIGHT FOG. WITH PIA
AND BMI CLEARING OUT FIRST IN THE EARLY MORNING HOURS...BELIEVE
SOME LIGHT FOG IS POSSIBLE. SO HAVE A THIS IN THE TAFS WITH A 3HR
TEMPO GROUP FOR LOWER VIS. COULD BE SOME LIGHT FOR AT SPI/DEC/CMI
BUT ONLY TEMPO SINCE THEY WILL NOT CLEAR OUT UNTIL AFTER SUNRISE.
WITH LOTS OF LOW LEVEL MOISTURE AROUND FROM THE RAIN LAT NIGHT AND
TODAY...BELIEVE ONCE THE SUN HITS IT...CU WILL DEVELOP FOR THE
LATE MORNING AND INTO THE AFTERNOON. WITH RIDGING AND ANTICYCLONIC
FLOW MOVING IN WILL GO WITH ONLY SCATTERED CU AND NO BROKEN CIGS.
HEIGHT OF CU SHOULD BE AROUND 3KFT. CU WILL DISSIPATE DURING THE
EVENING LEAVING CLEAR SKIES FOR THE EVENING HOURS. NORTH-NORTHEAST
WINDS WILL BECOME NORTHERLY DURING THE MORNING HOURS AND DECREASE
IN SPEED AS SURFACE RIDGING BUILDS IN FROM THE WEST. THEN EXPECT
NORTHWEST WINDS TOMORROW EVENING.

AUTEN

&&

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

$$


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