889
FXUS63 KILX 161118
AFDILX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE LINCOLN IL
518 AM CST SUN FEB 16 2025
KEY MESSAGES
- BREEZY WINDS AND COLDER TEMPERATURES ARE EXPECTED ACROSS CENTRAL
ILLINOIS TODAY. WINDS WILL GUST TO AROUND 30 MPH WITH
TEMPERATURES NEARLY STEADY OR FALLING MUCH OF THE DAY.
- AN EXTENDED PERIOD OF BITTERLY COLD TEMPS WILL BE IN PLACE
THROUGH THE UPCOMING WEEK. OVERNIGHT LOWS WILL FALL INTO THE
SINGLE DIGITS AND EVEN BELOW ZERO IN SPOTS EACH NIGHT WITH WIND
CHILL VALUES OF ZERO TO 15 OR 20 BELOW THROUGH FRIDAY.
- A SLOW MOVING WEATHER SYSTEM WILL BRING CHANCES FOR SNOW TO
PORTIONS OF CENTRAL ILLINOIS MONDAY THROUGH WEDNESDAY.
DISCUSSION
ISSUED AT 227 AM CST SUN FEB 16 2025
BLUSTERY AND TURNING COLDER TODAY...
LOW PRESSURE IS OVER THE UPPER OHIO VALLEY EARLY THIS MORNING AND
WILL CONTINUE TO DEPART THE REGION TO THE NORTHEAST. A COLD
CANADIAN AIRMASS IS IN PLACE TO OUR NORTHWEST WITH A CENTER OF
HIGH PRESSURE OVER THE CANADIAN ROCKIES AND RIDGING EXTENDING
SOUTH ACROSS THE GREAT PLAINS. STRONG COLD AIR ADVECTION IS IN
PLACE ACROSS CENTRAL ILLINOIS IN BETWEEN THESE TWO FEATURES. TEMPS
WILL FALL INTO THE 20S THIS MORNING AND WE WILL SEE LITTLE
RECOVERY DURING THE DAY.
MEANWHILE, COLD AIR ADVECTION WILL DRIVE STEEP LOW LEVEL LAPSE RATES
TODAY. THIS IN COMBINATION WITH THE TIGHT PRESSURE GRADIENT OVER THE
REGION WILL RESULT IN BLUSTERY CONDITIONS. HREF SUGGESTS HIGH
PROBABILITIES (80-100 PERCENT) OF WIND GUSTS EXCEEDING 30 MPH AT
SOME POINT TODAY, BUT LOW PROBS (<20%) OF EXCEEDING 40 MPH. THIS
IS SUPPORTED BY GFS/NAM FORECAST SOUNDINGS WHICH SHOW MEAN WINDS
AROUND 25KT WITHIN THE MIXED LAYER AND TOP OF THE CHANNEL WINDS
AROUND 30KT.
FINALLY FOR TODAY, THE STEEP LOW LEVEL LAPSE RATES WILL DRIVE WEAK
INSTABILITY WITHIN THE BOUNDARY LAYER WITH INSTABILITY POKING INTO
THE DENDRITIC GROWTH ZONE. THIS MAY ALLOW FOR A FEW FLURRIES OR
VERY LIGHT SNOW SHOWERS TO DEVELOP THIS AFTERNOON AND EARLY
EVENING. NO ACCUMULATIONS ARE EXPECTED AT THIS TIME.
CHANCE FOR SNOW MONDAY THROUGH WEDNESDAY...
SURFACE RIDGE AXIS SHIFTS TO OUR EAST MONDAY WHILE THE H85
BAROCLINIC ZONE SETS UP FROM MONTANA INTO WEST CENTRAL ILLINOIS.
ISENTROPIC ASCENT WILL INCREASE ACROSS THE BAROCLINIC ZONE AND
ALONG THE 280K-295K SURFACES IN RESPONSE TO A SLOW DIGGING UPPER
TROUGH OVER BC/ALBERTA MONDAY TO MONTANA LATE TUESDAY. THE CHANCE
FOR SNOW WILL INCREASE ALONG THE LOWER ILLINOIS RIVER VALLEY
INITIALLY MONDAY AND SPREAD TO THE I-70 CORRIDOR TUESDAY. THERE IS
PRETTY DECENT AGREEMENT BETWEEN THE DETERMINISTIC MODELS THIS
INITIAL AREA OF SNOW WILL SKIRT ALONG OUR SOUTHERN FORECAST AREA
COUNTIES WHILE MUCH OF CENTRAL ILLINOIS WILL REMAIN DRY. WHERE IT
DOES SNOW, A VERY DEEP DENDRITIC GROWTH ZONE FROM NEAR THE
SURFACE TO AROUND 600MB WILL BE PRESENT AND SHOULD PROVIDE A
FAVORABLE ENVIRONMENT FOR EFFICIENT SNOW PRODUCTION AND ABOVE
CLIMO SNOW TO LIQUID RATIOS.
AFOREMENTIONED UPPER WAVE WILL DEEPEN AND POSSIBLY CLOSE OFF ALOFT
AS IT DIGS ACROSS THE UPPER MIDWEST WEDNESDAY. SNOW WILL BECOME MORE
WIDESPREAD ACROSS THE MID MISSISSIPPI VALLEY WITH THE NORTHERN EDGE
OF THE SNOW SETTING UP SOMEWHERE OVER CENTRAL ILLINOIS. NBM
72-HOUR MEAN SNOWFALL THROUGH WEDNESDAY NIGHT HAS THE ONE INCH
SNOW CONTOUR FROM ROUGHLY BEARDSTOWN TO TERRE HAUTE IN WITH THE
HIGHEST AMOUNTS SOUTH OF THAT LINE. 90TH PERCENTILE BRINGS THE 3
INCH CONTOUR UP TO ROUGHLY THIS SAME LINE WITH AT LEAST MINOR
ACCUMULATIONS ACROSS THE ENTIRE AREA.
BITTERLY COLD WEEK AHEAD...
TONIGHT THROUGH FRIDAY NIGHT, EXPECT TEMPERATURES TO FALL IN THE
SINGLE DIGITS IF NOT BELOW ZERO EACH NIGHT/EARLY MORNING FOR MOST
OF CENTRAL ILLINOIS. WIND CHILL VALUES WILL FALL BELOW ZERO EACH
NIGHT FOR MOST OF THE AREA AS WELL, WITH SOME SPOTS MAINLY NEAR
THE I-74 CORRIDOR FLIRTING WITH COLD WEATHER ADVISORY CRITERIA
(-15DEGF OR COLDER). FOR THIS MORNING'S FORECAST PACKAGE, WILL BE
HOISTING A COLD WEATHER ADVISORY FOR STARK AND MARSHALL COUNTIES
OVERNIGHT INTO MONDAY MORNING.
DEUBELBEISS
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 517 AM CST SUN FEB 16 2025
LOW PRESSURE OVER THE UPPER OHIO VALLEY EARLY THIS MORNING WILL
DEPART THE MIDWEST LEAVING GUSTY NORTHWEST WINDS IN ITS WAKE
ACROSS CENTRAL ILLINOIS. WINDS WILL GUST IN THE 20-30 KT RANGE
MUCH OF THE DAY WITH THE STRONGEST WINDS EXPECTED LATE THIS
MORNING THROUGH THE AFTERNOON. MVFR CEILINGS SHOULD SLOWLY IMPROVE
THROUGH THE DAY BUT WILL NOT RETURN TO VFR UNTIL LATE IN THE
PERIOD.
DEUBELBEISS
ILX WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM CST MONDAY
FOR ILZ028-030.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page