915
FXUS63 KARX 260818
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
318 AM CDT SUN OCT 26 2025
KEY MESSAGES
- NEAR SEASONABLE TEMPERATURES WITH DAYTIME HIGHS IN THE 50S TO
LOW 60S AREA WIDE THROUGH MONDAY.
- PRECIPITATION CHANCES INCREASE OVERNIGHT MONDAY THROUGH
TUESDAY MORNING PRIMARILY WEST OF THE MISSISSIPPI RIVER.
DISCUSSION
ISSUED AT 305 AM CDT SUN OCT 26 2025
DRY THROUGH THE DAY MONDAY:
DRY START TO THE WEEK EXPECTED AS AN AMPLIFIED AREA OF UPPER
LEVEL HEIGHTS SEEN ON GOES UPPER LEVEL WATER VAPOR IMAGERY
RESIDES OVER THE UPPER MISSISSIPPI RIVER VALLEY. WHILE
TEMPERATURES WILL BE SLIGHTLY WARMER, DAYTIME HIGHS FROM THE
50S TO LOW 60S, STRONGEST RETURN FLOW REMAINS WEST OF THE
FORECAST AREA FROM THE NORTHERN PLAINS THROUGH SOUTHERN CANADA
THROUGH MIDWEEK. THE BOUNDARY BETWEEN THIS INCREASED LOW LEVEL
MOISTURE FLUX TO DRIER AIR DRIVEN BY ANTICYCLONIC FLOW SEEN
SAGGING SOUTH FROM SOUTHERN CANADA ON UPPER LEVEL WATER VAPOR
IMAGERY WILL LIE NEAR, JUST UPSTREAM, OF THE FORECAST AREA
THROUGH THE START OF THE WEEK (LREF).
PRECIPITATION CHANCES OVERNIGHT MONDAY INTO TUESDAY:
SUBSEQUENT PRECIPTIATION CHANCES WILL BE DRIVEN BY BROAD SYNOPTIC
TOUGHING TAKING SHAPE OVER THE NORTHWEST CONUS, CURRENTLY SEEN
LIFTING NORTH-NORTHEAST DICTATED BY THE UPSTREAM PERIPHERY OF
THE AFOREMENTIONED LOCALLY AMPLIFIED UPPER LEVEL RIDGE. A
SLIGHTLY SLOWER ONSET IN LREF PRECIPITATION PROBABILITIES (MORE
INTO TUESDAY MORNING) CAN BE TIED TO STRONGER INFLUENCE OF DRY,
EAST WINDS FROM ANTICYCLONIC FLOW OFF THE GREAT LAKES WITH A
WEAKER SOLUTION OF THE SURFACE LOW LIFTING NORTHEAST THROUGH THE
NORTHERN PLAINS MONDAY. REGARDLESS, HIGH CONFIDENCE (70-100%)
IN AT LEAST MEASURABLE PRECIPITATION WEST OF THE MISSISSIPPI
RIVER VALLEY THROUGH MIDWEEK HAS INCREASED OVER THE LAST FEW
LREF RUNS DUE TO A MORE EASTERLY SOLUTION TO UPSTREAM HIGHER
HEIGHTS (LREF PROB FOR 576 DAM AT 500MB). SHOULD THIS EASTERN
TREND CONTINUE, HIGHER PRECIPITATION CHANCES WOULD NEED TO BE
ADVECTED FARTHER EAST.
PRECIPITATION CHANCES THROUGH MIDWEEK:
EVENTUALLY AN ENHANCED UPPER LEVEL JET STREAK, OVER THE EASTERN
PACIFIC EARLY THIS MORNING ON GOES-18 DERIVED UPPER LEVEL WINDS,
DIGS AND CLOSES THE BROAD TROUGHING TO THE SOUTHEAST THROUGH
THE CENTRAL PLAINS INTO MIDWEEK DRIVING CYCLOGENESIS IN THE
MISSOURI THEN OHIO RIVER VALLEYS. THE CURRENT CONFIDENCE IN
LOCATION PLACES THE LOCAL FORECAST AREA ON THE EASTERN FOLLOWED
BY NORTHERN PERIPHERY OF THE EXTRATROPICAL CYCLONES INFLUENCE,
MORE AFFECTED BY SUBSIDENCE AND DRIER LOW LEVEL AIR FROM EAST
WINDS DUE TO ANOMALOUSLY HIGH UPPER LEVEL HEIGHTS (SPC
CLIMATOLOGY RAOBS) AND ANTICYCLONIC FLOW OVER JAMES BAY, HUDSON
BAY, CANADA. EXACT LOCATION OF THE LOW LEVEL TROUGH EXTENDING
NORTH-SOUTH THROUGH THE CENTRAL PLAINS WILL DETERMINE FINER
LOCATION OF CYCLOGENESIS AND RESULTANT LOCAL PRECIPITATION
CHANCES. THE ACCOMPANYING AXIS OF DILATATION WILL ALSO CAUSE
PRECIPITATION CHANCES TUESDAY NIGHT INTO WEDNESDAY.
CURRENT LREF CONFIDENCE OF 60-90% FOR 0.01"+ IN 24 HOURS LIES
WEST OF THE MISSISSIPPI RIVER LOCALLY IN SOUTHEAST MINNESOTA AND
NORTHEAST IOWA WITH 20-40% FOR 0.5".
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1156 PM CDT SAT OCT 25 2025
VFR CONDITIONS TO PREVAIL OVER THE NEXT 24 HOURS. BROKEN TO
SCATTERED STRATUS BETWEEN FL 040-070 CONTINUES ACROSS MUCH OF
THE AREA WITH SOME VERY LIGHT SHOWERS ACROSS PORTIONS OF NE
IOWA. THESE SHOWERS SHOULD STAY WELL SOUTH OF THE TERMINALS.
SOUTHEASTERLY WINDS ARE EXPECTED TO PICK UP LATER THIS MORNING
WITH GUSTS TO AROUND 20-25 KTS POSSIBLE AT THE RST TERMINAL.
GUSTS WILL TAPER OFF AS THE NIGHTTIME INVERSION SETS BACK UP
WITH SUSTAINED SPEEDS GENERALLY HOLDING BETWEEN 5-10 KTS.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...JAR
AVIATION...BARENDSE
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