Area Forecast Discussion
Issued by NWS Green Bay, WI

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000
FXUS63 KGRB 140856
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
256 AM CST SUN DEC 14 2014

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 255 AM CST SUN DEC 14 2014

EARLY THIS MORNING...WIDESPREAD DENSE FOG WAS LOCKED OVER ALL OF
CENTRAL WISCONSIN...WHILE THE DENSE FOG BECOMES MORE SPOTTY OVER
NORTHEAST AND EAST CENTRAL WISCONSIN. SURFACE ANALYSIS INDICATES A
WEAK TROUGH HOLDING ALONG THE LAKE MICHIGAN SHORELINE MAY BE
PROVIDING SOME MIXING AND HOLDING OFF WIDESPREAD FOG DEVELOPMENT.
MEANWHILE DRIZZLE HAS BEEN SLOW TO ARRIVE TO THE AREA AS THE RIDGE
AXIS BISECTS THE STATE FROM NORTH TO SOUTH EARLY THIS MORNING.
AREA RADARS TO THE WEST DO SHOW INCREASED RETURNS NEAR TO SUGGESTS
DRIZZLE WORKING INTO THE WESTERN HALF OF THE STATE EARLY THIS
MORNING...AND MAY BEGIN TO WORK INTO CENTRAL WISCONSIN BETWEEN 08Z
AND 10Z. GROUND TRUTH IN THE AREA INDICATES PATCHY DRIZZLE.  PROGS
IN AGREEMENT WITH SHIFTING THIS RIDGE AXIS TO LAKE MICHIGAN BY 6
AM AND COULD THEN EXPECT THE FOG TO BECOME MORE WIDESPREAD OVER
EASTERN WISCONSIN. WILL CONTINUE THE HEADLINE AS IS AND WILL MAKE
ANY ADJUSTMENTS TOWARD 12Z IF NEED BE. THERE MAY BE SOME SLIGHT
IMPROVEMENT LATER TODAY BUT ITS POSSIBLE ANOTHER DENSE FOG
ADVISORY MAY BE NEEDED FOR TONIGHT...AND ITS POSSIBLE SOME
LOCATIONS WILL NOT IMPROVE MUCH TODAY AND MAY NEED TO BE EXTENDED
THIS AFTERNOON.

FOR MONDAY...AFTER A PERIOD OF MORE FOG AND DRIZZLE IN THE
MORNING...LIGHT RAIN WILL BE ON THE INCREASE IN THE AFTERNOON
AS THE UPPER LOW WITH SURFACE LOW SYSTEM BEGINS TO LIFT NORTHEAST
FROM THE CENTRAL PLAINS TOWARD THE REGION.

WITH EXTENSIVE CLOUDS AND CONTINUED FEED OF WARM MOIST AIR INTO
THE REGION...TEMPS WILL FLUCTUATE VERY LITTLE TODAY INTO MONDAY.

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 255 AM CST SUN DEC 14 2014

SPLIT FLOW TO REMAIN INTACT THRU THE END OF THE WEEK WITH THE NRN
STREAM MOVING FROM THE PACIFIC NW ACROSS SRN CANADA AND A SRN
STREAM MOVING FROM CA ACROSS THE SRN HALF OF THE CONUS. AN INITIAL
SRN STREAM SYSTEM TO ALREADY BE ONGOING MON NGT...FOLLOWED BY A
WEAKER NRN STREAM SYSTEM MID-WEEK AND THEN ANOTHER POTENTIAL SRN
SYSTEM LATE IN THE WEEK. AFTER A RUN OF WELL ABOVE NORMAL TEMPS
ENDS ON TUE...TEMPS WL FALL TO NEAR SEASONAL NORMS THRU THU BEFORE
SLOWLY WARMING ONCE AGAIN TOWARD NEXT WEEKEND.

MODELS HAVE FINALLY COME INTO GOOD AGREEMENT IN TAKING THE SRN
STREAM CLOSED UPR LOW INTO SRN SECTIONS OF THE GREAT LAKES MON
NGT. MEANWHILE...THE MODERATE-INTENSITY SFC LOW TO TRACK FROM THE
MIDWEST NEWD TO SE WI/SRN LAKE MI BY 12Z TUE. LIGHT RAIN TO
ALREADY BE FALLING ACROSS ALL OF NE WI MON EVENING WITH AN
INVERTED SFC TROF EXTENDED FROM SW TO NE WI ACTING AS A FOCAL
POINT AND WARM/MOIST AIR CONTINUING TO FEED INTO THE REGION.
COOLER AIR WL BEGIN TO GET PULLED SEWD INTO WI AS THE PRIMARY
DEFORMATION ZONE SETS UP FROM SRN MN TO N-CNTRL WI. MODELS SEEM TO
BE A LITTLE SLOWER IN SENDING THIS COOLER AIR INTO NE WI AND IT
MAY HOLD THE START OF THE PCPN TYPE CHANGEOVER TIL AFTER MIDNGT
N-CNTRL...CLOSER TO DAYBREAK FOR FAR NE/PARTS OF CNTRL WI.
POTENTIAL STILL EXISTS FOR AN INCH OR LESS OF SNOW ACROSS N-CNTRL
WI WITH LITTLE ACCUMULATION ELSEWHERE. THE REST OF THE FCST AREA
WL REMAIN ALL RAIN THRU THE NGT. MIN TEMPS TO RANGE FROM THE MID
TO UPR 20S N-CNTRL TO THE UPR 30S NEAR MTW.

THE LAST OF THE RAIN IS EXPECTED TO CHANGE TO ALL SNOW ACROSS
E-CNTRL WI DURING THE MID TO LATE MORNING ON TUE AS THE SYSTEM
CONTS TO TRACK ACROSS THE GREAT LAKES. THE PROBLEM FOR SNOW
ACCUMULATION IS THAT THE HEAVIER QPF TO HAVE SHIFTED NORTH AND
EAST...THUS DO NOT ANTICIPATE MUCH IN THE WAY OF AMOUNTS. WL HAVE
TO KEEP AN EYE ON N-CNTRL WI AS MODEST CAA SENDS 8H TEMPS DOWN TO
AROUND -10C OVER WRN LAKE SUPERIOR AND WINDS TURN N-NW. THIS MAY
ALLOW FOR LAKE ENHANCEMENT TO DEVELOP AND LINGER THE SNOW CHCS
LONG WITH PERHAPS ANOTHER INCH OF SNOW POSSIBLE ACROSS VILAS CNTY.
EXPECT TEMPS TO ESSENTIAL BE STEADY OR SLOWLY FALL THRU THE DAY AS
THE CAA TAKES OVER.

A PIECE OF MID-LEVEL ENERGY IS FCST TO DROP SOUTH AND INTERACT
WITH A TRAILING NRN STREAM SHORTWAVE TROF TO GENERATE A BROAD
CLOSED UPR LOW OVER THE WRN GREAT LAKES/UPR MS VALLEY TUE NGT.
WHILE A FEW SNOW SHWRS OR FLURRIES ARE POSSIBLE OVER NE WI...THE
MAIN FOCUS TO BE ON THE LAKE EFFECT FOR N-CNTRL WI. DELTA-T VALUES
APPROACH 20 WITH A FAVORABLE NW TRAJ. HAVE RAISED POP VALUES
ACROSS NRN WI WITH THE SNOWBELT OF VILAS CNTY RAISED TO LIKELY
CATEGORY. A MINOR ACCUMULATION IS POSSIBLE...BUT FINAL NUMBERS ARE
STILL QUESTIONABLE DUE TO THE LOCATION OF THE UPR LOW. THE LAKE
EFFECT THREAT FOR N-CNTRL WI WL CONT INTO WED AS THE UPR LOW
SETTLES OVER THE GREAT LAKES. THE REST OF THE FCST AREA TO SEE A
FEW PEEKS OF SUNSHINE WITH MAX TEMPS WED CLOSER TO NORMAL FOR MID-
DECEMBER.

ANY LINGERING LAKE EFFECT SNOW SHWRS WL COME TO AN END WED NGT AS
A CANADIAN HI PRES BUILDS TOWARD THE WRN GREAT LAKES AND DRIER AIR
ARRIVES. AS THE HI PRES MOVES INTO THE GREAT LAKES ON THU...EXPECT
TO SEE PARTLY CLOUDY SKIES WITH A CONTINUATION OF NEAR NORMAL
TEMPS. THIS AREA OF HI PRES IS PROGGED TO REMAIN IN OUR GENERAL
VICINITY THRU FRI...KEEPING NE WI WEATHER QUIET AND TEMPS PERHAPS
A COUPLE DEGS WARMER THAN THU. AS ONE WOULD EXPECT ON DAY 7...THE
MODELS ARE HAVING TIMING/MOVEMENT ISSUES WITH THE NEXT SRN STREAM
SYSTEM FOR LATE IN THE WEEK. THE GFS IS FASTER/FARTHER NORTH AND
PULLS PCPN AS CLOSE AS SE WI FRI NGT. THE ECMWF IS SLOWER/FARTHER
SOUTH AND KEEPS ANY PCPN WELL TO OUR SOUTH. FOR NOW...WL KEEP OUR
FCST DRY FOR BOTH FRI AND SAT WITH TEMPS SLIGHTLY ABOVE NORMAL.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1147 PM CST SAT DEC 13 2014

AT TAF ISSUANCE TIME...LIFR/IFR VSBYS AND CIGS COVERED CENTRAL AND NORTH
CENTRAL WISCONSIN...WHILE VSBYS AND CIGS AT LOCATIONS FARTHER TO
THE EAST WERE MAINLY MVFR BUT GRADUALLY LOWERING.

LIGHT WINDS...DEW POINTS WELL ABOVE NORMAL OVER SNOW-COVER...AND
INCREASING LOW LEVEL MOISTURE FROM MELTED SNOW CONTRIBUTED MUCH TO
THE DRIZZLE AND LOW VSBYS IN FOG.

EXPECT CONDITIONS TO BE MAINLY LIFR/IFR THROUGHOUT THE NIGHT WITH
SOME IMPROVEMENT DURING THE DAY ON SUNDAY TO MVFR...MAINLY WHERE
THERE IS LITTLE OR NO SNOW-COVER. CONDITIONS WILL PROBABLY
DETERIORATE AGAIN AROUND SUNSET.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&

$$

SHORT TERM.....TDH
LONG TERM......AK
AVIATION.......MG






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