FXUS63 KGRB 051010
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
410 AM CST SAT DEC 5 2009

.SHORT TERM...TODAY THROUGH SUNDAY. 

EVOLVING PATTERN AS UPPER LOW/TROF THAT HAS BEEN OVER AREA PULLS
NORTH AND EAST OF THE AREA WITH FLOW BECOMING MORE ZONAL. AT 09Z
LIGHT SNOW SHOWER/FLURRY ACTIVITY CONTINUES OVER MUCH OF
CWA...THOUGH SAT IMAGERY INDICATING CLEARING BEGINNING TO PUSH
INTO SOUTHWEST WI. MODEL CROSS SECTIONS SHOW THIS LESSENING OF THE
MOISTURE FOR TODAY WITH PREVIOUS FORECAST SEEMINGLY ON TRACK WITH
CLOUD TRENDS.

FOR TONIGHT...MODELS RATHER CONSISTENT IN SPITTING OUT SOME LIGHT
QPF OVER THE NORTHERN HALF OF THE CWA AS WEAK SURFACE BOUNDARY
MOVES THROUGH AREA AND WEAK SHORT WAVE MOVES EAST OUT OF THE
PLAINS. HAVE ADDED SMALL POPS TO COVER.

HAVE BACKED OFF ON LAKE EFFECT LATE TONIGHT AND SUNDAY NORTH
CENTRAL. WINDS EITHER TOO LIGHT FOR BANDS TO PENETRATE THAT FAR
INLAND OR THEY TEND TO BACK TOO WESTERLY OVER THE LAKE.

SOME RECOVERY IN TEMPS TODAY AND SUNDAY...BACK TO NEAR SEASONAL NORMS.

.LONG TERM...SUNDAY NGT THRU NXT FRI. OLD MAN WINTER TO MAKE HIS
PRESENCE KNOWN NXT WEEK AS THREE SEPARATE SYSTEMS ARE EXPECTED TO
IMPACT NE WI. TIMING/TRACK OF THE FIRST TWO SYSTEMS ARE HANDLED
PRETTY WELL BY THE MDLS WITH THE SECOND STORM THE ONE TO WATCH AS
HVY SNOW/BLOWING SNOW A DEFINITE POSSIBILITY OVR THE SE HALF OF WI
TUE NGT THRU WED. STILL SOME QSTNS FOR SYSTEM NUMBER THREE LATE
NXT WEEK AND HAVE TAKEN A PASS ON THIS ONE FOR NOW.

MDLS REMAIN CONSISTENT IN SWINGING A SHRTWV TROF NEWD FROM THE
CNTRL PLAINS TOWARD THE NRN IL VCNTY BY 12Z MON. A WEAK SFC WAVE
WL ALSO RISE NE INTO NRN IL/SRN LK MI ALONG A STALLED FNTL BNDRY.
INCREASING ISEN ASCENT...COMBINED WITH MODEST Q-G FORCING AND ADDL
LIFT FROM THE LEFT EXIT RGN OF THE UPR JET...ALL POINT TO A CHC OF
SNOW MAINLY OVR THE SRN 3/4 OR SO (GENERALLY SOUTH OF HIGHWAY 8)
OF THE FCST AREA. HAVE KEPT THE LIKELY POPS FOR E-CNTRL WI SUNDAY
NGT CLOSER TO THE BETTER FORCING AND LIFT...WHERE AN INCH OR TWO
OF ACCUMULATION IS POSSIBLE.

THIS SYSTEM HEADED TOWARD THE ERN GREAT LKS RGN ON MON...BUT WL
NEED TO LINGER SNOW CHCS THRU THE MORNING HRS. BASED ON THE
CURRENT TIMING OF THE SYSTEM'S DEPARTURE...HAVE BUMPED THE POPS TO
LIKELY ALONG THE LKSHR ESP WITH AN INITIAL NE WND PERHAPS ADDING
SOME LK ENHANCEMENT. E-CNTRL WI COULD SEE ANOTHER INCH OF SNOW
BEFORE DIMINISHING AT MIDDAY. BY MON AFTERNOON...WNDS BACK MORE
N-NW WHICH LEADS TO POTENTIAL LK EFFECT SNOW SHWRS OVR NRN WI. IT
APRS THO THAT ANY ACCUMULATIONS WOULD BE VERY MINOR AS WNDS ARE
EXPECTED TO CONT SLOWLY BACKING THRU THE AFTERNOON.

OTHER THAN A FEW LINGERING SNOW SHWRS OR FLURRIES OVR THE NORTH
MON EVENING...A BRIEF BREAK IN THE SNOW CHCS ARE EXPECTED AS HI
PRES QUICKLY MOVS THRU THE RGN. DEPENDING ON THE AMT OF CLD CVR
MON NGT AND SNOWCOVER...TEMPS COULD BE RATHER CHILLY. HAVE KNOCKED
OFF A COUPLE OF DEGS FROM THE PREV FCST WITH READINGS PRETTY MUCH
IN THE TEENS THROUGHOUT THE ENTIRE FCST AREA. ALL EYES THEN TURN
TO THE SRN PLAINS ON TUE WHERE THE NXT PROMINENT SYSTEM IS FCST TO
BE ORGANIZING. A 140 KT UPR JET IS PROGGED TO ROUND THE BASE OF A
MODERATELY STG SHRTWV TROF AND HELP REV UP CYCLOGENESIS VCNTY
OKLAHOMA. MDLS ALL INDICATE AN INVERTED TROF WL EXTEND NE FROM THE
INTENSIFYING LOW PRES INTO THE GREAT LKS BY TUE AFTERNOON. GULF
MSTR ALREADY BEING TAPPED AND WORKING NORTH TOWARD WI...THUS
EXPECT TO SEE LGT SNOW BEGIN TO OVERSPREAD THE FCST AREA. SRN
SECTIONS OF THE FCST AREA COULD ALREADY HAVE AN INCH OF SNOW BY
SUNSET AND IS ONLY APRS TO BE THE BEGINNING.

SFC LOW MOVS NE ACROSS THE MO VALLEY RGN AND JUST NORTH OF THE
OHIO RIVER VALLEY (VCNTY CNTRL INDIANA) BY 12Z WED. THIS TRACK IS
JUST A TOUCH SOUTH OF MDL RUNS FROM 24 HRS AGO. NONETHELESS...LOOK
FOR SNOW TO GRADUALLY INCREASE IN INTENSITY AS FRONTOGENETICAL
FORCING INCREASES AND A DIFFLUENT FLOW ALOFT EXISTS. BASED ON FCST 
SNDNGS PLACEMENT OF THE FAVORABLE -15C DENDRITIC GROWTH ZONE OVR
THE SE HALF OF THE FCST AREA...EXPECT TO SEE A GOOD AMT OF SNOW ON
THE GROUND BY DAYBREAK WED MORNING GENERALLY SE OF AN ISW-MNM LINE.
SOME MODEST DEBATE LINGERS INTO WED AS TO WHETHER THE SFC LOW WL
SLIDE NE TOWARD LK ONTARIO OR CONT DIGGING N-NE TOWARD LK HURON.
THE LATTER SOLN WOULD BRING THE DEFORMATION ZONE INTO NE WI...THUS
MORE ACCUMULATION AND SNOW LASTING THRU THE ENTIRE DAY. HAVE RAISED
POPS OVR THE EAST TO LIKELY FOR THIS POSSIBILITY. ADD IN SOME
GUSTY NE BACKING NW WNDS ON WED AND WE COULD BE LOOKING AT SOME
TREACHEROUS DRIVING CONDITIONS WITH LIMITED VSBYS. 

SNOW SHWRS AND FLURRIES WL LINGER OVR THE NORTH WED NGT AS ARCTIC
AIR GETS TUGGED SWD TOWARD THE NRN GREAT LKS BEHIND THE DEPARTED
STORM. BACKING WNDS MORE W-NW APRS TO BE A LIMITING FACTOR TO ADDL
ACCUMULATIONS OVR THE NORTH. OTHERWISE...HI PRES BUILDS INTO THE
RGN FOR THU BRINGING A RETURN OF SOME SUNSHINE...BUT COLD TEMPS TO
NE WI. WE WL HAVE TO WATCH FOR A THIRD SYSTEM COMING OUT OF THE
ROCKIES FOR THE END OF NXT WEEK. RIGHT NOW...MDLS ARE STILL
DIFFIRENT ON THE TRACK (HEAD TOWARD THE GREAT LKS OR SLIDE TO OUR
SOUTH). THUS...MADE NO CHGS TO FRI'S FCST AT THIS TIME.
&&

.AVIATION...DRIER AIR WORKING INTO THE AREA THIS MORNING WILL
BRING AN END TO THE PERSISTENT SNOW SHOWER/FLURRY ACTIVITY FROM
SOUTH TO NORTH TODAY WITH CIGS/VSBYS IMPROVING TO VFR LEVELS THIS
AFTERNOON. A WEAK SURFACE BOUNDARY AND ANOTHER UPPER WAVE WILL
BRING A RETURN TO THE LIGHT SNOW ACTIVITY TONIGHT.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
TE/KALLAS