823
FXUS63 KARX 191121
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
521 AM CST SUN JAN 19 2020
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 320 AM CST SUN JAN 19 2020
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL TROUGH OVER
THE GREAT LAKES REGION WITH NORTHWEST FLOW ALOFT OVER THE NORTHERN
PLAINS. SHORTWAVE TROUGH OVER WESTERN WISCONSIN AND EASTERN
MINNESOTA IS PRODUCING FLURRIES MAINLY ALONG THE MISSISSIPPI
RIVER VALLEY PER LATEST KARX RADAR.
TODAY INTO TONIGHT...A COUPLE OF SHORTWAVE TROUGHS EMBEDDED IN THE
NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE UPPER GREAT LAKES/NORTHERN
PLAINS. THE COMBINATION OF A COLD AIRMASS IN PLACE...WEAK
LIFT/FORCING ASSOCIATED WITH EACH PASSING SHORTWAVE TROUGH...WILL
PRODUCE LIGHT SNOW OR FLURRIES ACROSS MUCH OF THE FORECAST AREA. ANY
MEASURABLE SNOWFALL MAY OCCUR WITH A STRONGER SHORTWAVE TROUGH
THIS EVENING/TONIGHT. SNOWFALL AMOUNTS WILL MAINLY BE LESS THAN AN
INCH.
TEMPERATURES ARE EXPECTED TO BE SLIGHTLY BELOW NORMAL TODAY INTO
MONDAY WITH HIGHS IN THE SINGLE DIGITS ABOVE ZERO TO AROUND 20
DEGREES AND LOWS IN THE SINGLE DIGITS BELOW AND ABOVE ZERO.
LONG TERM
(MONDAY THROUGH SATURDAY)
ISSUED AT 320 AM CST SUN JAN 19 2020
SHORTWAVE TROUGH TRACKS SOUTH OF FORECAST AREA DURING THE DAY MONDAY
AND SHORTWAVE RIDGING BUILDS INTO THE UPPER GREAT LAKES MONDAY
NIGHT INTO TUESDAY. SOUTHERLY WINDS ON THE BACKSIDE OF THE UPPER
LEVEL RIDGE WILL ADVECT WARMER TEMPERATURES INTO THE FORECAST AREA
TUESDAY AFTERNOON. 925MB TEMPERATURES WARM TO MINUS 9 TO MINUS 3
DEGREES CELSIUS BY 00Z WEDNESDAY. HIGH TEMPERATURES ARE EXPECTED
TO BE IN THE TEENS TO 20S.
FIRST IMPULSE EJECTING OUT OF THE UPPER LEVEL TROUGH OVER THE ROCKY
MOUNTAINS BREAKS DOWN UPPER LEVEL RIDGE WEDNESDAY. FORCING/VERTICAL
MOTION INCREASES ACROSS FORECAST AREA WEDNESDAY AFTERNOON AND
CHANCES OF PRECIPITATION INCREASE THROUGH THE DAY. PRECIPITATION
TYPE WILL BE AN ISSUE...AS BUFKIT SOUNDINGS SUGGEST THE SOUTHERN
HALF OF THE FORECAST AREA TO BE NEAR FREEZING OR SLIGHTLY ABOVE
ALOFT/NEAR SURFACE. AT THIS TIME...NORTHERN PORTIONS WILL BE ALL
SNOW WITH THE ATMOSPHERE COLUMN TO BE BELOW FREEZING.
MAIN FORECAST CONCERNS WEDNESDAY NIGHT THROUGH SATURDAY ARE
PRECIPITATION CHANCES AND PRECIPITATION TYPE THROUGH THE PERIOD. THE
19.00Z GFS/ECMWF/GEM ARE IN DECENT AGREEMENT IN CUTTING OFF UPPER
LEVEL LOW OVER THE CENTRAL UNITED STATES THURSDAY INTO
FRIDAY...HOWEVER MODELS ARE IN DISAGREEMENT ON PLACEMENT AND
MOVEMENT OF THE UPPER LEVEL LOW. PIECES OF ENERGY ROTATING AROUND
THE UPPER LEVEL LOW WILL PROVIDE PRECIPITATION CHANCES THROUGH THE
PERIOD. BIGGEST CONCERN WILL BE PRECIPITATION TYPE...AS THE
DETERMINISTIC MODELS SUGGEST TEMPERATURES WARMING TO NEAR OR ABOVE
FREEZING. THIS WILL PRODUCE CHANCES OF A WINTRY MIX OVER THE
FORECAST AREA. AT THIS TIME...WILL CONTINUE WITH THE MENTION OF RAIN
OR SNOW AND LATER FORECAST WILL DETERMINE EXACT AMOUNTS.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 521 AM CST SUN JAN 19 2020
COLD CYCLONIC FLOW ALOFT WILL KEEP MVFR CLOUD COVER GOING THROUGH
THE PERIOD ALONG WITH SCATTERED FLURRIES. PLAN ON PREVAILING
NORTHWEST WINDS THROUGH THE PERIOD. GUSTINESS AT KRST IN THE
20-25KT RANGE IS EXPECTED TO SUBSIDE BY LATER THIS AFTERNOON.
ARX WATCHES/WARNINGS/ADVISORIES
WI...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR WIZ032-033-041-
053>055-061.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-019-
029-030.
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...DAS
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