148
FXUS63 KARX 251037
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
537 AM CDT SAT OCT 25 2025
KEY MESSAGES
- MORNING SHOWERS PROGRESS EAST INHIBITED BY LOW LEVEL DRY AIR,
POTENTIALLY PROVIDING MINIMAL ACCUMULATIONS ACROSS THE
FORECAST AREA.
- WARMER WEEKEND WITH DAYTIME HIGHS IN THE MID 50S TO 60S ON
SUNDAY.
- PRECIPITATION CHANCES RETURN MONDAY NIGHT.
DISCUSSION
ISSUED AT 312 AM CDT SAT OCT 25 2025
EARLY MORNING OBSERVATIONS:
LOW CONFIDENCE, LOW IMPACT FORECAST LAY AHEAD AS AN INITIALLY
PROGRESSIVE PATTERN EARLY THIS MORNING PLACES A LOW-LEVEL
BOUNDARY NEAR THE FORECAST AREA THROUGH NEXT WEEK. A TIGHTENED
AREA OF CYCLONICALLY ROTATING CLOSED UPPER LEVEL HEIGHTS ON
GOES WATER VAPOR IMAGERY LOOPS SAGGING SOUTHEAST THROUGH
MINNESOTA INTO WESTERN WISCONSIN DRIVING PRECIPITATION WEST OF
THE MISSISSIPPI RIVER VALLEY THIS MORNING WITH INCREASED
FILAMENTS OF MOISTURE IN WATER VAPOR IMAGERY SEEN DOWNSTREAM
THROUGH WISCONSIN. THE BEST SYNOPTIC FORCING IS DRIVING HIGHER
PRECIPITATION RATES ALONG THE MISSISSIPPI RIVER VALLEY IN EAST-
CENTRAL MINNESOTA WHILE LIGHTER REFLECTIVITY SEEN TO THE SOUTH
OVER NORTHEAST IOWA, OVERACHIEVING WHEN COMPARED TO PREVIOUS
FORECASTS, SEEMINGLY OVERCOMING LOW LEVEL DRY AIR IN AN AREA OF
CONVERGENCE BETWEEN THE AFOREMENTIONED LOW AND RETURN FLOW
ORIGINATING FROM A LARGER CLOSED LOW OVER THE SOUTHERN PLAINS.
SHOWER CHANCES TODAY:
EXPECT THE UPPER LOW CLOSED LOW TO CONTINUE WEAKENING THIS
MORNING AS THE SOUTHEASTERN TRAJECTORY RESULTS IN UPPER LEVEL CONFLUENCE
WITH THE LARGER PATTERN OVER THE CENTRAL PLAINS WHILE ADVECTING
INTO A DRIER AIRMASS. DURATION AND EXTENT OF WEAKENING WILL
DETERMINE EASTERN EXTENT OF PRECIPITATION AND LOW LEVEL MOISTURE
ADVECTION AS EAST WINDS ON MISSISSIPPI RIVER VWPS (I.E., ARX &
DVN) ARE PART OF A MUCH DRIER AIRMASS (25.00Z RAOBS). HOWEVER,
A SLIGHTLY STRONGER SOLUTION TO THE UPPER LEVEL LOW AT AFD
ISSUANCE HAS ADVECTED /SOME/ LOW LEVEL MOISTURE FARTHER EAST,
EVIDENT IN AFOREMENTIONED OVERACHIEVING RADAR REFLECTIVITY
RETURNS OVER THE WESTERN HALF OF THE LOCAL FORECAST AREA.
THEREFORE, GIVEN EARLY MORNING OBSERVATIONS, HAVE BLENDED IN
MORE HIGH RESOLUTION HRRR MODEL POPS THROUGH THIS MORNING GIVEN
A MORE EASTERLY SOLUTION TO LOW LEVEL MOISTURE COMPARED TO OTHER
HREF MEMBERS. EVENTUALLY THE DRY AIR IS EXPECTED TO WIN OUT
THROUGH THE LATE MORNING AS THE SYNOPTIC FORCING PROGRESSES OUT
OF THE FORECAST AREA. LINGERING SHOWER CHANCES ALONG A NORTHWEST
TO SOUTHEAST LINE BIFURCATING THE FORECAST AREA THIS AFTERNOON
WILL HAVE TO BE ADDRESSED IN COMING FORECAST DEPENDING ON HOW
THIS MORNING PLAYS OUT. MAY REQUIRE A VIRGA FORECAST.
GIVEN THE LIGHTENING PRECIPITATION EXPECTATION, OVERALL IMPACTS
REMAIN LOW WITH HREF MAXIMUM OF 0.5"+ LIMITED TO A PIXEL IN
EASTERN MINNESOTA THIS MORNING AND SOUTHEAST MINNESOTA FROM
ONGOING REFLECTIVITY OVER THE NEXT FEW HOURS.
WARMER WEEKEND, SEASONABLE NEXT WEEK W/ PRECIPITATION CHANCES:
SUBSEQUENT BUILDING UPPER LEVEL HEIGHTS SEEN ON EARLY MORNING WATER
VAPOR IMAGERY LEE OF THE ROCKY MOUNTAINS QUICKLY AMPLIFY OVER THE
UPPER MIDWEST THIS WEEKEND (LREF) AS DECREASING GLOBAL WAVE NUMBER
SLOWS THE SYNOPTIC PATTERN. RESULTANT TIGHTENING OF THIS
MOISTURE BOUNDARY THROUGH THE WEEKEND INTO NEXT WEEK OWED TO THE
UPPER MISSISSIPPI RIVER VALLEY BEING ON THE SOUTHWESTERN
PERIPHERY OF AN ANOMALOUS (SPC RAOB CLIMATOLOGY AT MOOSONEE,
ON) AREA OF UPPER LEVEL HEIGHTS (LREF 80% CONFIDENCE IN 500MB
ISOHEIGHTS) OVER JAMES BAY, HUDSON BAY, CANADA. STRONG LOW LEVEL
MOISTURE THROUGH THE NORTHERN PLAINS INTO CENTRAL CANADA (LREF
80% CONFIDENCE IN 925MB DEWPOINT TEMPERATURES NEAR WESTERN
HUDSON BAY) AIDED BY AN ATMOSPHERIC RIVER CURRENTLY IMPACTING
THE PACIFIC WEST COAST RESULTS IN A SHARP GRADIENT IN ENSEMBLE
CONFIDENCE FOR PRECIPITATION ALONG OUR WESTERN PERIPHERY
THROUGH MIDWEEK.
AN EASTERN SHIFT IN THE RIDGES ISOHEIGHT GRADIENT OVER SOUTHERN
CANADA IN EPS (00Z) 500MB ISOHEIGHT PROBABILITIES INCREASED
LOCAL CONFIDENCE FOR 0.01" OF QPF FROM MONDAY NIGHT THROUGH
TUESDAY, UP TO 50-80% ACROSS THE FORECAST AREA. A WEAKER
SOLUTION TO THE MID LEVEL ANTICYCLONE IN THE GEFS HAS HAD A
SIMILAR RESULT, INCREASING TO 60-80% PROBABILITIES FOR 0.01" OF
QPF IN FROM MONDAY NIGHT THROUGH TUESDAY. THE ANOMALOUS
MOISTURE ADVECTION ALSO RESULTED IN INCREASED PROBABILITIES FOR
HIGHER AMOUNTS IN BOTH GLOBAL ENSEMBLES, 30-70% FOR 0.1" AND
10-40% FOR 0.5".
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 536 AM CDT SAT OCT 25 2025
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. WIDESPREAD LIGHT
SHOWERS CONTINUE TO OVERSPREAD THE UPPER MISSISSIPPI VALLEY
EARLY THIS MORNING. AS THESE SHOWERS ARE BATTLING LOW LEVEL DRY
AIR, MOST UPSTREAM OBSERVATIONS HAVE REMAINED VFR WITH
VISIBILITIES ONLY LOWERING SLIGHTLY. ANY INSTANCES OF MVFR HAVE
BEEN VERY BRIEF AND WIDELY SCATTERED SO HAVE REMOVED THE PROB30S
FROM EARLIER AS CONFIDENCE IN MVFR CIGS CONTINUES TO DECREASE.
COVERAGE OF SHOWERS WILL BE ON A DOWNWARD TREND LATER THIS
MORNING WITH THE TERMINALS LIKELY STAYING DRY 18Z AND ONWARDS.
WINDS WILL REMAIN OUT OF THE SOUTHEAST THROUGH THE PERIOD WITH
SPEEDS STAYING AT OR BELOW 12 KTS.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...JAR
AVIATION...BARENDSE
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