873
FXUS63 KILX 251704
AFDILX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE LINCOLN IL
1204 PM CDT MON AUG 25 2025
KEY MESSAGES
- SEASONABLY COOL CONDITIONS ARE FORECAST THIS WEEK, WITH DAILY
HIGHS GENERALLY IN THE 70S AND LOWS IN THE UPPER 40S TO MID
50S.
- THERE IS A 10% CHANCE OF A LIGHT SHOWER THURSDAY INTO THURSDAY
NIGHT, BUT OTHERWISE THE WORK WEEK IS FORECAST TO REMAIN DRY.
DISCUSSION
ISSUED AT 114 AM CDT MON AUG 25 2025
***** COOL AND DRY THROUGH AT LEAST MIDWEEK *****
TEMPERATURES CONTINUE TO PLUMMET EARLY THIS MORNING AMIDST
OPTIMAL RADIATIONAL COOLING CONDITIONS, WITH LOWS AROUND 50
DEGREES BY SUNRISE. AS SURFACE HIGH PRESSURE SETTLES SOUTHEASTWARD
INTO THE REGION TODAY, GRADIENTS WILL SLACKEN AND HENCE NORTHWEST
WINDS WILL BE A LITTLE LOWER COMPARED TO YESTERDAY. DESPITE THE
WEAKER COOL ADVECTION, THE CHILLY START TO THE DAY WILL RESULT IN
TEMPERATURES ONLY REACHING THE LOW TO MID 70S THIS AFTERNOON.
WE'LL RINSE AND REPEAT TOMORROW AND THEN ADD JUST A COUPLE DEGREES
WEDNESDAY, MAINTAINING DRY CONDITIONS AND AN AUTUMN-LIKE
OVERNIGHT CHILL.
***** LESS COOL, SPOTTY SHOWER THURSDAY INTO FRIDAY(?) *****
THERE'S NOW SOME QUESTION AS TO WHETHER WE'LL REMAIN DRY THROUGH THE
END OF THE WORK WEEK, AS BOTH THE DETERMINISTIC GFS AND ECMWF PAINT
SOME LIGHT QPF ACROSS OUR NORTHERN COUNTIES THURSDAY INTO THURSDAY
NIGHT WITH A SUBTLE SHORTWAVE IMPULSE. WHILE THE PROBABILITY OF
MEASURABLE RAIN IN ANY GIVEN 6 HOUR PERIOD REMAINS LESS THAN 20% DUE
TO TIMING DIFFERENCES AMONG THE MODELS THAT HAVE PRECIP, RAW LREF
SUGGESTS CHANCES FOR PRECIP AT SOME POINT BETWEEN WEDNESDAY NIGHT
AND EARLY FRIDAY MAY BE AS HIGH AS 30-40% NEAR AND NORTH OF THE I-74
CORRIDOR. ANY PRECIP THAT DOES FALL IS LIKELY TO BE LIGHT, THOUGH;
NBM CHANCES FOR MORE THAN A TENTH OF AN INCH ARE LESS THAN 10%
ACROSS THE BOARD. IN FACT, WHETHER BIAS-CORRECTING A WET BIAS IN THE
RAW GUIDANCE OR FOR SOME OTHER REASON, NBM HAS LESS THAN A 15%
CHANCE FOR ANY PRECIP THURSDAY INTO FRIDAY. WHILE THIS MAY BE
UNDERSELLING THINGS, CONFIDENCE IS LOW AND IMPACTS WOULD BE MINIMAL,
SO WE'LL LET THOSE SUB-MENTIONABLE POPS STAND IN OUR FORECAST FOR
NOW. AHEAD OF THAT SHORTWAVE, THURSDAY IS SLATED TO BE THE WARMEST
DAY OF THE WORK WEEK WITH HIGHS AROUND 80, WHILE CONDITIONS TURN A
LITTLE COOLER FRIDAY WITH ANOTHER SURGE OF COOL ADVECTION BEHIND A
WEAK FRONT.
***** FORECAST CONFIDENCE DECREASES THIS WEEKEND *****
THIS WEEKEND, BOTH DETERMINISTIC AND ENSEMBLE DEPICTIONS OF THE
SYNOPTIC PATTERN DIVERGE, RESULTING IN AMBIGUITY IN OUR WEATHER.
THE GFS WOULD HAVE A CUT OFF LOW GIVING US SEVERAL DAYS OF CLOUD
COVER, PERIODS OF RAIN, AND COOL CONDITIONS BEGINNING ON SATURDAY,
WHILE THE ECMWF KEEPS US DRY THROUGH MONDAY. CLUSTER ANALYSIS
SUGGESTS THE GFS SOLUTION IS AMONG THE RAINY OUTLIERS, WITH AN 80%
CHANCE OF PRECIP (BUT ONLY 5/100 MEMBERS, ALL FROM THE GEFS) IN
CLUSTER 4; THE REMAINING 3 CLUSTERS, BEING LESS TROUGHY, EACH HAVE
LESS THAN A 15% CHANCE OF RAIN SATURDAY INTO SUNDAY.
BUMGARDNER
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1204 PM CDT MON AUG 25 2025
A RIDGE OF HIGH PRESSURE WILL REMAIN WEST OF THE TERMINALS
THROUGH THE PERIOD WITH A MODEST NW BREEZE IN PLACE ACROSS CENTRAL
ILLINOIS. EXPECT SOME LOW END GUSTS OF AROUND 18KT THIS AFTERNOON
THROUGH AROUND SUNSET, THEN WINDS SHOULD DROP OFF BELOW 10 KT
THIS EVENING AND OVERNIGHT. VFR CONDITIONS WILL PREVAIL THROUGH
THE PERIOD.
DEUBELBEISS
CLIMATE
ISSUED AT 250 AM CDT MON AUG 25 2025
RECORD LOW TEMPERATURES FOR TUESDAY AND WEDNESDAY:
LOCATION TUESDAY WEDNESDAY
-------- -------- ---------
BLOOMINGTON 42 (1910) 43 (1894)
CHAMPAIGN 46 (1910) 46 (1904)
CHARLESTON 46 (1910) 45 (1910)
DECATUR 44 (1910) 45 (1910)
LINCOLN 37 (1910) 39 (1910)
OLNEY 44 (1917) 48 (1968)
PEORIA 41 (1910) 43 (1910)
SPRINGFIELD 49 (1910) 51 (2015)
GEELHART
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
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