850
FXUS63 KARX 271125
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
625 AM CDT TUE OCT 27 2020
SHORT TERM
(TODAY THROUGH THURSDAY)
ISSUED AT 220 AM CDT TUE OCT 27 2020
CHILLY DAY FOR THE REGION TODAY AS THE COLDEST AIR OF THE VERY YOUNG
WINTER SEASON SWINGS THROUGH. 850 MB TEMPS STILL AROUND -10 C THIS
MORNING WITH NAEFS 850 ANOMALIES NEAR -2. AFTER A START WHERE SOME
LOCATIONS COULD NEAR/BREAK RECORDS, HIGHS ARE EXPECTED TO ONLY CREEP
INTO THE MID/UPPER 30S - ALMOST 20 DEGREES BELOW NORMAL.
THE RESPONSIBLE UPPER LEVEL TROUGH IS PUSHING EAST THOUGH, TAKING
THE HEART OF THE COLDER AIR WITH IT AND ALLOWING FOR SOME MODERATION
TO THE RECENT COLD. MEANWHILE, A RIPPLE IN THE UPPER LEVEL FLOW IS
PROGGED TO DROP ACROSS NORTHERN PARTS OF THE REGION ON THU. RUNNING
INTO SOME DRY AIR AND THE GFS/NAM CURRENTLY KEEP ANY LIGHT PCPN TO
NORTHERN PORTIONS OF MN/WI. FARTHER SOUTH, A CLOSED 500 MB LOW IS
PROGGED TO LIFT OUT OF THE DESERT SW, WEAKENING AS IT LIFTS
NORTHEAST INTO THE TN/OH RIVER VALLEYS. MODELS HAVE BEEN TRENDING
WITH A BIT MORE SOUTHERN TRACK WITH THIS FEATURE, WHICH WOULD KEEP
ANY PCPN THREAT ALSO SOUTH. GOING TO FOLLOW SUIT, KEEPING PCPN
THREAT OUT OF THE AREA.
LONG TERM
(FRIDAY THROUGH MONDAY)
ISSUED AT 220 AM CDT TUE OCT 27 2020
NO CHANGE IN THE EC AND GFS WHEN IT COMES TO PROMOTING A MORE ZONAL,
QUICKER MOVING FLOW FOR THE END OF THE WEEK, INTO NEXT WEEK.
SHORTWAVE RIDGING PROGGED TO WORK ACROSS THE REGION FOR THE WEEKEND,
WITH THE POTENTIAL FOR STRONGER, BROADER RIDGE BUILDING WORKING IN
FOR THE START OF NEXT WEEK. TEMPS STILL LOOKING TO BE ON THEIR WAY
UP AS A RESULT, AND EXPECT A RETURN TO SOMETHING MORE SEASONABLE FOR
LATE OCT/EARLY NOV. SAT MIGHT BE THE WARMEST DAY OF THE WEEK.
WHILE THE MODELS ARE STILL PROMOTING A MOSTLY DRY, QUIET END TO THE
WEEK, BOTH THE GFS AND EC FAVOR DROPPING A SHORTWAVE TROUGH FROM
WESTERN CANADA TO ACROSS THE UPPER MISSISSIPPI RIVER VALLEY SAT
NIGHT. CURRENT SOLUTIONS KEEP THE BULK OF THE FORCING/SATURATION AND
THUS QPF TO THE NORTH, ALTHOUGH ALSO DRAG A COLD FRONT ACROSS THE
REGION. COULD SEE SOME PCPN CHANCES FOR NORTHERN PARTS OF THE REGION
BUT WILL RIDE THE MODEL BLENDS FOR NOW. THE FRONT WILL BRING A QUICK
SHOT OF COOLER AIR, BUT SHOULD REBOUND ALREADY BY MON.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 625 AM CDT TUE OCT 27 2020
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SOUTHWEST WINDS
WILL INCREASE TODAY, GUSTING TO NEAR 20 KTS AT TIMES, ESPECIALLY
AT RST. WINDS ARE EXPECTED TO STAY JUST ON EITHER SIDE OF 10 KTS
OVERNIGHT. EVEN SO, GUIDANCE SUGGESTS SOME LOW LEVEL WIND SHEAR
WILL BE PRESENT, OWING TO 40 KT WINDS ALOFT. FOR NOW, ONLY
INCLUDED MENTION AT LSE, AS SURFACE WINDS AT RST LOOK LIKE THEY
COULD STAY UP A BIT MORE, BUT WILL NEED TO KEEP AN EYE ON TRENDS
IN GUIDANCE TODAY.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...CA
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