595
FXUS63 KARX 100452
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1152 PM CDT FRI MAY 9 2025
KEY MESSAGES
- ABOVE NORMAL TEMPS THROUGH THE MID PART OF NEXT WEEK - HIGHS IN
THE 70S THIS WEEKEND WITH 80S INTO NEXT THU CURRENTLY EXPECTED.
- LOW END RAIN CHANCES (20%) SOUTH-EAST TUE/WED. HIGHER THREAT FOR
SHOWERS/STORMS MOVE IN THU/FRI AREAWIDE (40-50%).
DISCUSSION
ISSUED AT 120 PM CDT FRI MAY 9 2025
OVERVIEW: AN UPPER LEVEL RIDGE REMAINS ON TRACK TO AMPLIFY AS IT
BUILDS OVER THE PLAINS STATES FOR THE WEEKEND. MEANWHILE, A CUT OFF,
CLOSED 500 MB LOW WILL BE WOBBLING AROUND THE GULF STATES. AS WE
MOVE INTO THE NEW WORK WEEK, THE RIDGE WILL GRADUALLY SHIFT EAST
WHILE THE SOUTHERN LOW MEANDERS NORTHWARD - FAVORED TO SIT OVER THE
OH/TN RIVER VALLEYS BY TUE EVENING. THIS WILL WORK TO SLOW THE
EASTWARD PROGRESSION OF THE RIDGE. 3 OUT OF THE 4 WPC CLUSTER WANT
TO SHIFT THE RIDGE AXIS OVER THE NEW ENGLAND STATES BY 00Z FRI
- BUT THERE IS ONE SLOWER HOLD OUT (AND OVER 1/3 OF THE ENSEMBLE
MEMBERS) THAT HAS THE RIDGE OVER THE GREAT LAKES UNTIL 00Z SAT. THAT
USED TO BE THE SCENARIO THE BULK OF THE EPS AND GEFS MEMBERS FAVORED
- BUT DAY-TO-DAY MODEL RUNS SHOW A TREND TOWARD THE SLIGHTLY FASTER
SHIFT EAST. SENSIBLE WEATHER OUTCOMES WOULD BE A QUICKER END TO THE
WARM/MOSTLY DRY CONDITIONS. NBM SIDES WITH THIS TREND AND WILL
FOLLOW SUIT.
NUTSHELL? STAYING ABOVE NORMAL FOR TEMPS THROUGH THE MIDDLE PART OF
NEXT WEEK WITH ONLY LOW END (IF ANY) RAIN CHANCES.
TEMPERATURES: VERY WARM AIR IS SET TO FUNNEL NORTHWARD UNDER THE
RIDGE THIS WEEKEND INTO NEXT WEEK. CURRENT POSITIONING OF THE RIDGE
AXIS WILL KEEP THE WARMEST/HOTTEST AIR WEST OF THE LOCAL AREA
- FENDED OFF BY THE CLOSED UPPER LEVEL LOW. THE WARMTH IS
STRONGLY ANOMALOUS FOR THIS TIME YEAR WITH MAX TEMP EFIS AROUND 1.0
AND SOTS OF +1 ACROSS THE NORTHERN PLAINS. AGAIN THOUGH, THE UPPER
LEVEL PATTERN WANTS TO KEEP THIS AIR WEST. LOCALLY, HIGHS 10 TO 15
DEGREES ABOVE NORMAL STILL TRACKING IN THE EPS AND GEFS WITH THE
WARMEST AIR MOVING IN FOR THE NEW WORK WEEK.
RAIN CHANCES: A COLD FRONT IS CURRENTLY SLIDING SOUTHEAST ACROSS
SD/NORTHWEST MN. WHILE SATURATION IS RATHER MEAGER AND CONFINED TO
THE MID LEVELS (10KFT OR SO), SATELLITE SHOWS A THIN BAND OF CLOUDS
ASSOCIATED WITH THE FRONT. LIGHT RETURNS ON LATEST RADAR IMAGERY.
CAMS EXPAND/PERK UP THE CONVECTION A BIT AS WE MOVE THROUGH THE
AFTERNOON, TAPPING INTO 250+ J/KG SBCAPE. AWFULLY HIGH BASED AND
AWFULLY DRY IN THE SUB CLOUD LAYER THOUGH. RAIN WILL HAVE A
DIFFICULT TIME REACHING THE GROUND OUTSIDE OF ANY POTENTIAL
STORM/DEEPER CORE. COULD EXPERIENCE SOME ENHANCED WIND GUSTS DUE TO
THE INVERTED V-SOUNDINGS - EVEN SOME "DRY" LIGHTNING (LIGHTING
WITHOUT RAINFALL). CONVECTION LOOKS SPOTTY AT BEST RIGHT NOW. WILL
CONTINUE 20% CHANCES FOR NORTHWEST PORTIONS OF THE FORECAST AREA
(GENERALLY NORTH OF I-90/I-94) INTO EARLY EVENING.
THE CLOSED UPPER LEVEL IS SLATED TO WORK UNDER THE RIDGE AND COULD
SPIRAL BITS OF SHORTWAVE ENERGY ACROSS SOUTHERN/EASTERN PORTIONS OF
THE THE FORECAST AREA ON TUE/WED. THE ATMOSPHERE REMAINS RATHER DRY
THROUGH THE COLUMN THOUGH, SO HOW MUCH MOISTURE THERE WOULD BE FOR
ANY FORCING TO WORK ON IS QUESTIONABLE. INDICATIONS FOR WEAK
INSTABILITY THOUGH, SO IF CONVECTION CAN GET SPARKED, A FEW STORMS
ARE POSSIBLE. LOW END PCPN CHANCES IN THE NBM LOOK REASONABLE (20%)
AT THIS TIME - MORE FAVORED EAST/SOUTHEAST OF THE LOCAL AREA.
MOVING INTO THU/FRI, AN UPPER LEVEL TROUGH IS MOVING IN FROM THE
WEST WITH ACCOMPANYING COLD FRONT, LOW LEVEL WARM AIR ADVECTION AND
A FEED OF LOW LEVEL MOISTURE TRANSPORT. BETTER SET UP FOR
SHOWERS/STORMS. INSTABILITY WOULD BE ON THE INCREASE AND MIGHT HAVE
SOME WIND SHEAR TO PLAY WITH TOO. DEPENDING ON THE EVOLUTION AND
TIMING OF THIS SYSTEM, SOME STRONGER STORMS CERTAINLY POSSIBLE. WAY
TOO FAR OUT TO PUT TOO MUCH STOCK INTO ANY KIND OF RISK YET - BUT
SOMETHING TO KEEP AN EYE. PROBABLY THE NEXT BEST CHANCE FOR
WIDESPREAD, WETTING RAINS FOR THE AREA.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1152 PM CDT FRI MAY 9 2025
SLOWLY SAGGING SOUTHEAST HIGH PRESSURE HAS WEAKENED WINDS OVER
THE LAST FEW HOURS. EXPECT WINDS TO STAY MOSTLY NORTH THROUGH
THE EARLY MORNING, TURNING NORTHEAST THROUGH LATE MORNING.
DIURNAL MIXING WILL INCREASE THEM A BIT, SUSTAINED AT 7-8KTS.
ALBEIT VERY LIGHT AND VARIABLE, THE CLOCKWISE TURN RESUMES
SATURDAY NIGHT, BECOMING SOUTH SOUTHEAST BY THE END OF THE
10.06Z TAF PERIOD.
VFR PREVAILS THROUGH THE 10.06Z TAF PERIOD.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BARENDSE
AVIATION...JAR
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