646
FXUS63 KDVN 271946
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
246 PM CDT MON OCT 27 2025
KEY MESSAGES
- TEMPERATURES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL THROUGH THE
FINAL WEEK OF OCTOBER
- A LARGE STORM SYSTEM IS EXPECTED TO IMPACT THE REGION TUESDAY
THROUGH WEDNESDAY, BRINGING THE NEXT CHANCES OF WIDESPREAD
RAINFALL TO THE REGION, ALONG WITH WINDY CONDITIONS TUESDAY
NIGHT THROUGH WEDNESDAY, WITH GUSTS OVER 30 MPH POSSIBLE
- RAINFALL TOTALS WITH THE TUESDAY/WEDNESDAY SYSTEM HAVE SOME
DOWN SLIGHTLY BUT ARE LIKELY TO RANGE FROM AROUND 0.25-0.50
INCHES OVER NORTHWESTERN ILLINOIS TO AROUND 0.90 INCHES OR
MORE ALONG AND SOUTH OF A FAIRFIELD TO BURLINGTON LINE.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 150 PM CDT MON OCT 27 2025
HIGH PRESSURE CONTINUES TO SIT TO THE NORTHEAST RESULTING IN
EAST WINDS OF 10 TO 20 MPH AND GUSTS UP TO 25 MPH. TEMPERATURES
AT 2 PM RANGE FROM 59 DEGREES AT DUBUQUE TO 64 DEGREES AT
MACOMB.
HIGH PRESSURE IS FORECAST TO MOVE INTO WESTERN ONTARIO TONIGHT
AS A SHORTWAVE TROUGH DIGS INTO THE PLAINS AND BEGINS TO
STRENGTHEN. MOISTURE ALOFT IS FORECAST TO SLOWLY INCREASE
TONIGHT CAUSING CLOUDS TO MOVE INTO THE AREA AND THICKEN
OVERNIGHT. WINDS ARE FORECAST TO REMAIN EASTERLY AT 5 TO 10 MPH.
THE INCREASE IN CLOUD COVER WILL ALLOW TEMPERATURES TO BE
WARMER THAN LAST NIGHT WITH TEMPERATURES RANGING FROM THE UPPER
40S IN FAR SOUTHEAST IOWA AND NORTHEAST MISSOURI TO THE LOWER
40S IN FAR NORTHWEST ILLINOIS.
LONG TERM /TUESDAY THROUGH SUNDAY/
ISSUED AT 150 PM CDT MON OCT 27 2025
THE PACIFIC NW LONGWAVE TROUGH IS PROGGED TO ARRIVE ON TUESDAY, WITH
CHANCES OF RAIN INCREASING AFTER 12Z/7 AM TUESDAY MORNING BUT
MAY HOLD OFF UNTIL AFTER 18Z/1PM DEPENDING ON HOW QUICKLY
SATURATION TAKES PLACE. MODEL TIME/HEIGHTS SHOW LOW LEVEL
DRYNESS LINGERING ACROSS THE AREA ESPECIALLY THE NORTHEAST HALF
OR NORTHEAST OF A LINE FROM CEDAR RAPIDS TO THE QUAD CITIES TO
GALESBURG. CAMS ALSO SUGGEST THAT IT WILL TAKE A LITTLE BIT OF
TIME FOR THE COLUMN TO SATURATE, SO ONLY OUR WESTERN CWA COULD
SEE LIGHT RAIN BEFORE EXPANDING EASTWARD. EVENTUALLY, AS LARGE-
SCALE LIFT INCREASES AND AN ATTENDANT SURFACE COLD FRONT BEGINS
TO MOVE IN, MOISTURE AHEAD OF THE BOUNDARY LOOKS TO INCREASE AS
PWATS BETWEEN 0.8" TO 1.0" PER THE HREF ENSEMBLE MEAN. MUCH OF
THE GLOBAL DETERMINISTIC AND LREF CLUSTER ANALYSIS ENSEMBLE
MEMBERS AGREE ON A CUT-OFF UPPER LOW DEVELOPING JUST SOUTH OF
OUR REGION, MEANING A SLOWER, STRONGER SYSTEM IS LIKELY TO
DEVELOP. MOISTURE APPEARS TO BE FAVORABLE TO LINGER ACROSS OUR
SOUTHERN CWA DUE TO THIS EVOLUTION. NBM EXCEEDANCE PROBABILITIES
OF TOTAL RAINFALL OF A HALF INCH TUESDAY/WEDNESDAY RANGES FROM
30-50% ACROSS OUR NORTHEAST TO 60-80% ACROSS OUR SOUTHWEST.
GIVEN THE DRY CONDITIONS WE'VE HAD LATELY AND EXPANDING DROUGHT,
THIS WILL BE BENEFICIAL RAINFALL. A LARGE GRADIENT IN RAINFALL
TOTALS FROM EASTERN IOWA INTO NORTHWEST ILLINOIS IS POSSIBLE
WITH THIS STORM SYSTEM WITH DRY AIR BEING PULLED INTO THE SYSTEM
ESPECIALLY IN FAR NORTHWEST ILLINOIS, NORTH OF HIGHWAY 30 WHERE
LESS THAN A QUARTER OF AN INCH OF RAIN IS POSSIBLE AND PARTS OF
STEPHENSON COUNTY MAY SEE LESS THAN A TENTH OF AN INCH. AREAS
WEST OF A FAIRFIELD TO MACOMB LINE COULD SEE BETWEEN 0.6 AND
0.90 INCHES WHICH IS SLIGHTLY LOWER THAN PREVIOUS FORECASTS.
THE OTHER ASPECT OF THIS UPCOMING SYSTEM WILL BE A TIGHTENING
PRESSURE GRADIENT AND DEEPER BOUNDARY LAYER MIXING ON WEDNESDAY,
WHICH SHOULD SUPPORT GUSTY CONDITIONS. THE 50TH PERCENTILE OF
THE NBM FOR PEAK WIND GUSTS IS RANGING BETWEEN 30 TO 40 MPH, SO
SOMETHING WE WILL NEED TO KEEP AN EYE ON AS WE GET CLOSER TO
WEDNESDAY. WILL THESE WINDS REACH WIND ADVISORY CRITERIA? AT
THIS TIME, IT DOESN'T APPEAR LIKELY, GIVEN THE LREF
PROBABILITIES OF GUSTS 40 MPH OR STRONGER ARE ONLY AROUND 10
PERCENT.
EVENTUALLY, THE TROUGH WILL EXIT THE REGION BY THURSDAY, MAKING WAY
FOR A PERIOD OF CALMER WEATHER THROUGH THE UPCOMING WEEKEND. A
COOLER AIR MASS WILL RESULT IN SOME CHILLY NIGHTS FOR WEDNESDAY
NIGHT THROUGH THE END OF THE WEEK, WITH LOWS IN THE 30S EACH NIGHT.
DAYTIME HIGHS WILL CONTINUE TO BE IN THE 50S. BEYOND FRIDAY,
MODELS SHOW DEEP NORTHWEST FLOW ALOFT WITH THE POTENTIAL FOR
DISTURBANCES PASSING TO OUR NORTH AND EAST TO CLIP THE AREA AND
BRING LOW CHANCES FOR RAIN SHOWERS ON SATURDAY AND SUNDAY.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1229 PM CDT MON OCT 27 2025
GUSTY EAST WINDS ARE FORECAST TO CONTINUE THROUGH 21 TO 22 UTC
THIS AFTERNOON BEFORE WINDS DIMINISH. A STORM SYSTEM IS FORECAST
TO DIG INTO THE PLAINS TONIGHT INTO TUESDAY MORNING. THIS WILL
LEAD TO A GRADUAL INCREASE AND THICKENING OF CLOUD COVER AFTER
06 UTC. CURRENTLY CONDITIONS ARE FORECAST TO REMAIN VFR THROUGH
12 UTC WITH THE POSSIBILITY OF MVFR CEILINGS AT KCID, KMLI, AND
KBRL AFTER 12 UTC BUT CONFIDENCE IS LOW ON WHEN THE TIMING THAT
THIS WILL OCCUR. PRECIPITATION IS NOT EXPECTED THROUGH THE TAF
PERIOD.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...COUSINS
LONG TERM...SCHULTZ/COUSINS
AVIATION...COUSINS
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