Area Forecast Discussion
Issued by NWS La Crosse, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KARX 160504
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1104 PM CST SAT NOV 15 2014

.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CST SAT NOV 15 2014

FOCUS IS ON ACCUMULATING SNOW THROUGH THIS EVENING.

SURFACE OBSERVATIONS SHOWING WIDESPREAD 1-2SM LIGHT SNOW FALLING
ACROSS SOUTHEAST MN/NORTHEAST IA. 1 TO 2 INCHES HAS ALREADY FALLEN
ACROSS PORTIONS OF SOUTHEAST MN ACCORDING TO REPORTS. RADAR MOSAIC
SHOWS A SHIELD OF SNOW CONTINUING TO SPREAD EAST FROM SOUTHEAST
MN/NORTHEAST IA INTO SOUTHWEST WI. WATER VAPOR SHOWING MAIN MID-
LEVEL TROUGH PRODUCING THE LIFT FOR THE SNOW PUSHING EAST ACROSS THE
DAKOTAS/NORTHERN NEB.

LOOK FOR SNOW TO CONTINUE INTO THIS EVENING AS THE AFOREMENTIONED
TROUGH PUSHES EAST TOWARD THE UPPER MISSISSIPPI VALLEY REGION.
STRONGEST ISENTROPIC LIFT AHEAD OF 700-300MB PV ANOMALY LOOKS TO BE
PRETTY MUCH SHUT DOWN BY 06Z...THEREBY ENDING THE ACCUMULATING SNOW.
AS SUCH...THINKING CURRENT WINTER WEATHER ADVISORIES/SNOW AMOUNTS
LOOK ON TARGET WITH NO CHANGES PLANNED.

EXPECT A FEW LINGERING LIGHT SNOW SHOWERS/FLURRIES SUNDAY MORNING
BEFORE WEAK INTERIM RIDGING/SUBSIDENCE SHUTS THIS DOWN.
OTHERWISE...A CHILLY DAY ON TAP WITH HIGHS ONLY IN THE UPPER TEENS
ACROSS SOUTHEAST MN...AND IN THE 20S ALONG AND EAST OF THE
MISSISSIPPI RIVER.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 240 PM CST SAT NOV 15 2014

FOR LATER SUNDAY NIGHT INTO MONDAY...ANOTHER REINFORCING BLAST OF
ARCTIC AIR PUSHES INTO THE REGION ON BLUSTERY NORTHWEST WINDS. NAM
INDICATING STRONG 700-300MB ANOMALY/LOW-LEVEL FRONTOGENESIS WITH THE
ARCTIC FRONT AS IT PUSHES THROUGH LATE SUNDAY NIGHT/EARLY MONDAY
MORNING. DUE TO THIS FORCING...COULD SEE SCATTERED SNOW SHOWERS
ALONG THE FRONT AND THEN MORE SNOW SHOWERS ON MONDAY DUE TO STEEP
LOW LEVEL LAPSE RATES IN DEEP CYCLONIC FLOW. IN ADDITION...WILL
LIKELY SEE AREAS OF BLOWING SNOW...ESPECIALLY ACROSS THE MORE WIND
PRONE AREAS OF SOUTHEAST MN/NORTHEAST IA WHERE ACCUMULATING SNOW
OCCURRED SATURDAY/SATURDAY EVENING. WILL HAVE TO KEEP AN EYE ON THIS
FOR POTENTIAL HEADLINE IF BLOWING SNOW BECOMES MORE WIDESPREAD.

UNSEASONABLY COLD NORTHWEST FLOW CONTINUES THROUGH THE REST OF THE
PERIOD. ECMWF/GFS SHOWING A TROUGH SWINGING THROUGH THE REGION
TUESDAY NIGHT AND EXITING WEDNESDAY MORNING FOR ANOTHER SHOT AT SOME
LIGHT SNOW. PLAN ON HIGHS MAINLY IN THE TEENS TUESDAY AND IN THE 20S
ON WEDNESDAY. YET ANOTHER DOSE OF ARCTIC AIR IS EXPECTED BEHIND THE
DEPARTING WAVE WITH HIGHS ON THURSDAY BACK DOWN INTO THE TEENS.

ECMWF AND GFS A BIT AT ODDS FOR FRIDAY AND SATURDAY. ECMWF MAINTAINS
A DRY/COLD NORTHWEST FLOW REGIME WHEREAS THE GFS BUILDS 500MB
HEIGHTS FRIDAY INTO SATURDAY. THE GFS ALSO GENERATES SOME LIGHT IN
WARM AIR ADVECTION. MODEL CONSENSUS YIELDS A DRY FRIDAY/SATURDAY
WITH HIGHS IN THE UPPER TEENS/20S FRIDAY...MODERATING INTO THE
MIDDLE 20S/LOWER 30S SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1104 PM CST SAT NOV 15 2014

SNOW CONTINUES TO FALL ACROSS THE TAF SITES...WITH VISIBILITIES
OSCILLATING BETWEEN MVFR AND IFR AS HEAVIER BANDS MOVE THROUGH.
CEILINGS ARE ALSO OSCILLATING BETWEEN VFR AND MVFR. MEANWHILE...
THE BACK EDGE OF THE SNOW WAS PROGRESSING QUICKLY EASTWARD ACROSS
MN AND IA. MUCH OF THE VISIBILITY REDUCTION DUE TO THE SNOW SHOULD
BE THROUGH BY 08-09Z WITH MAYBE A FEW ADDITIONAL TENTHS OF
ACCUMULATION. CEILINGS REMAIN TRICKY...BUT ANTICIPATING THEM TO
SETTLE AROUND MVFR AS LOWER STRATUS UNDER/WEST OF THE BACK EDGE OF
THE SNOW MOVES IN. SKIES HAVE CLEARED OUT ALONG I-29 AND THIS
CLEARING IS ALSO PUSHING EASTWARD AT A GOOD CLIP. SPED UP THE
SCATTERING OUT TIME IN THE TAFS TO 16-17Z. VFR CONDITIONS THEN
LOOK TO CONTINUE UNTIL LATE EVENING WHEN AN ARCTIC COLD FRONT
APPROACHES THE TAF SITES. IT APPEARS A BAND OF SNOW SHOWERS SHOULD
FORM ALONG THE FRONT...BRINGING AT LEAST CEILINGS DOWN TO MVFR.
VISIBILITIES COULD FALL TO MVFR OR EVEN IFR FOR A BRIEF TIME TOO.

EXPECT SOUTHERLY WINDS LESS THAN 10 KT TO VEER SOUTHWESTERLY THIS
AFTERNOON AND PICK UP SLIGHTLY AS THE ARCTIC FRONT APPROACHES.
STRONGER NORTHWEST WINDS ARE ON TRACK FOR MONDAY.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
     MNZ086>088-094>096.

IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
     IAZ008>011-018-019-029-030.

&&

$$

SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.