Area Forecast Discussion
Issued by NWS Green Bay, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 KGRB 232037
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
237 PM CST TUE DEC 23 2014

FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 237 PM CST TUE DEC 23 2014

MAIN FCST CONCERNS DEAL WITH THE DEMISE OF ONE SYSTEM AND ITS
ASSOCIATED SNOW TNGT AND THEN TRYING TO FIGURE OUT THE PATH OF THE
NEXT SYSTEM TOWARD THE GREAT LAKES ON WED.

THE 20Z MSAS SFC ANALYSIS SHOWED A WEAKENING AREA OF LOW PRES OVER
CNTRL WI MOVING ALONG A QUASI-STNRY BOUNDARY. THIS BOUNDARY WAS
SEPARATING WARM...MOIST AIR ON SOUTH WINDS OVER ERN WI FROM COOL...
MOIST AIR OVER WRN WI ON NORTH WINDS. RADAR MOSAIC CONTINUED TO
SHOW PCPN PIVOTING AROUND THE SFC LOW WITH MAINLY LIGHT RAIN OR
DRIZZLE OVER ERN WI AND EITHER LIGHT SNOW OR A RAIN/SNOW MIX OVER
CNTRL WI. PLAN ON CANCELING THE WINTER WX ADVY FOR ALL BUT VILAS/
ONEIDA COUNTIES WHERE SNOW INTENSITY IS LIGHT OR MIXED PCPN HAS
TAKEN OVER.

SYSTEM OVER THE GREAT LAKES REGION WL CONT TO DRIFT NE AND
STEADILY WEAKEN TNGT AS MAIN ENERGY SHIFTS TOWARD THE TN/OHIO
RIVER VALLEYS WHERE A STRENGTHENING SFC LOW TO RESIDE. FCST
SOUNDINGS INDICATE A LOSS OF MID-LEVEL SATURATION WHICH WOULD
DIMINISH ANY PCPN MAINLY TO EITHER FREEZING DRIZZLE OR DRIZZLE
DEPENDING ON SFC TEMPS. LOW-LEVELS OF THE ATMOSPHERE REMAIN
MOIST...SO PATCHY FOG TO BE A GOOD BET. ANOTHER MILD NGT ON TAP
ACROSS THE FCST AREA WITH MIN TEMPS ONLY RANGING FROM AROUND 30
DEGS N-CNTRL TO THE LWR TO MID 30S NEAR LAKE MI.

EVEN AT THIS LATE DATE...THE MODELS CONT TO STRUGGLE WITH THE
MOVEMENT OF THIS SFC LOW AS IT LIFTS N-NE INTO THE GREAT LAKES ON
WED. AN ERN TRACK (TOWARD DETROIT) PER ECMWF/GEM WOULD ESSENTIALLY
KEEP ANY SNOW POTENTIAL TO OUR EAST AND LEAVE NE WI CLOUDY WITH
ONLY A MINIMAL CHC OF ANY PCPN. A WRN TRACK (TOWARD CNTRL SECTIONS
OF LWR MI) PER NAM/GFS WOULD BRING THE THREAT OF MEASURABLE SNOW
TO ERN WI. THE FINAL SOLUTION MAY NOT BE KNOWN UNTIL THE SFC LOW
ACTUALLY DEVELOPS OVER THE OZARKS AND MAKES IT MOVE TO THE N-NE.
FOR NOW...HAVE SPLIT THE MODEL DIFFERENCE WHICH BRINGS A GLANCING
BLOW TO FAR ERN WI WED AFTERNOON...BUT HAVE KEPT ANY SNOW
ACCUMULATIONS TO LESS THAN AN INCH. ANYONE WITH TRAVEL PLANS
TOWARD SE WI OR NRN IL WL WANT TO CHECK THE LATEST FCSTS AS TRAVEL
MAY BECOME QUITE MESSY DOWN THAT WAY. MAX TEMPS FOR WED WL RANGE
FROM THE LWR 30S OVER N-CNTRL WI TO THE MID 30S ACROSS ERN WI.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 237 PM CST TUE DEC 23 2014

PROGS CONTINUE TO HINT OF SOME PRECIPITATION BRUSHING OVER FAR
EASTERN WISCONSIN WEDNESDAY EVENING UNTIL THE UPPER LOW SYSTEM
SHIFTS EASTWARD. AFTER A PERIOD OF BLUSTERY NORTHWEST WINDS
WEDNESDAY EVENING...DIMINISHING WINDS EXPECTED OVERNIGHT AS A WEAK
RIDGE OF HIGH PRESSURE WORKS INTO THE AREA.

XMAS DAY EXPECTED TO BE QUIET...THEN LIGHT SNOW WILL BE ON THE
INCREASE LATE IN THE WEEK AS A TROUGH OF LOW PRESSURE AND MID
LEVEL SHORT WAVE SLIDE OVER THE MID SECTION OF THE COUNTRY. PROGS
SUGGEST THE LIGHT SNOW APPEARS TO BE FOCUSED IN THE TRAILING
BAROCLINIC PORTION FROM NORTHWEST WISCONSIN LATE THURSDAY NIGHT
INTO FRIDAY BEFORE TROUGH PASSAGE FRIDAY AFTERNOON INTO EVENING.
FORECAST TEMPS SUGGEST A VERY LIGHT MIX POSSIBLE OVER EAST CENTRAL
WISCONSIN FRIDAY AFTERNOON.

THE QUIET ZONAL FLOW WITH SLIGHTLY COOLER THAN NORMAL TEMPERATURES
WILL CONTINUE INTO THE WEEKEND. MEDIUM RANGE MODELS ARE NOT
INDICATING MUCH SNOW WITH A SHORT WAVE DROPPING INTO THE GREAT
LAKES REGION WHICH DEEPENS THE TROUGH OVER THE REGION EARLY NEXT
WEEK. THERE IS SOME AGREEMENT WITH AN ARCTIC SURGE OF AIR BY THE
MIDDLE OF NEXT WEEK AND USUALLY A CLIPPER TYPE SYSTEM PRECEDES
THIS BUT SO FAR NO INDICATION. AVAILABLE PROGS SUGGESTS SOME
SLIGHT MODERATION IN TEMPS LATE NEXT WEEK.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1201 PM CST TUE DEC 23 2014

AVIATION TRAVEL WL CONT TO BE IMPACTED BY A PAIR OF SYSTEMS
AFFECTING THE GREAT LAKES OVER THE NEXT 24 HOURS. THE FIRST SYSTEM
ALREADY IN WI AND WAS PRODUCING MAINLY IFR CIGS/VSBYS IN EITHER
SNOW...A RAIN/SNOW MIX OR DRIZZLE. CIGS/VSBYS COULD RISE INTO THE
MVFR RANGE LATER THIS AFTERNOON/EVENING OVER ERN WI AS A DRY SLOT
ROTATES NEWD OVER LAKE MI. THIS SYSTEM TO SLOWLY MOVE NE AND
WEAKEN TNGT...HOWEVER PLENTY OF LOW-LEVEL MOISTURE LEFT BEHIND TO
KEEP IFR CONDITIONS INTACT. THE NEXT SYSTEM IS FCST TO LIFT NE
TOWARD THE ERN GREAT LAKES ON WED AND COULD CLIP FAR ERN WI WITH
LIGHT SNOW. IFR CONDITIONS ARE FCST TO CONT THRU MOST OF WED WITH
PERHAPS A BRIEF CLIMB TO MVFR IN THE AFTERNOON.
&&

.HYDROLOGY...
ISSUED AT 237 PM CST TUE DEC 23 2014

MILD CONDITIONS OVER NORTHEAST WISCONSIN THROUGH WEDNESDAY ALONG
WITH RAINFALL AMOUNTS OF 0.25 TO 0.75 INCHES THROUGH TUESDAY
AFTERNOON MAY AFFECT ICE CONDITIONS ON AREA RIVERS AND LAKES.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ005-
010.
&&

$$

SHORT TERM.....KALLAS
LONG TERM......TDH
AVIATION.......KALLAS
HYDROLOGY......TDH






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