000
FXUS63 KGRB 312321
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
521 PM CST SAT JAN 31 2015

UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 240 PM CST SAT JAN 31 2015

MAJOR WINTER STORM IS EXPECTED TO PASS WELL SOUTH OF THE AREA
TONIGHT AND SUNDAY...WITH THE SOUTHERN PORTION OF THE FORECAST
AREA ON THE NORTHERN FRINGE OF THE STORM. SOME CONCERN ON
HOW FAR NORTH THE SNOW WILL MAKE IT INTO OUR AREA. INCREASING
NORTHEAST WINDS WILL USHER IN COLDER AND DRIER AIR FROM HIGH
PRESSURE SYSTEM NEAR HUDSON BAY RESIDES. TYPICALLY IN THESE
SITUATIONS...WILL TREND TOWARDS THE NAM MODEL ON QPF AND
SNOW TOTALS TONIGHT AND SUNDAY. LIGHT SNOW IS EXPECTED TO
SURGE NORTHWARD TO ABOUT HIGHWAY 29 LATE TONIGHT INTO SUNDAY
MORNING...THEN THE NORTHERN EDGE OF THE SNOW WILL GRADUALLY
SHIFT SOUTH LATER SUNDAY MORNING AND AFTERNOON.

FOR MANITOWOC AND KEWAUNEE COUNTIES...DRY AIR WILL BE BATTLING
LONGER FETCH OVER LAKE MICHIGAN TONIGHT INTO SUNDAY BEFORE WINDS
BACK MORE NORTHERLY. CONFIDENCE WAS NOT HIGH ENOUGH TO ISSUE
A WINTER WEATHER ADVISORY FOR MANITOWOC COUNTY. WILL ISSUE SPECIAL
WEATHER STATEMENT TO HIGHLIGHT SNOWFALL TOTALS OF 1 TO 3 INCHES
AND GUSTY NORTHERLY WINDS CREATING AREAS OF BLOWING AND DRIFTING
SNOW.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 240 PM CST SAT JAN 31 2015

PCPN TRENDS AND COLD TEMPERATURES WILL BE THE MAIN FCST CONCERNS.

LINGERING LAKE-ENHANCED SNOW SHOWERS WILL IMPACT EAST CENTRAL WI
SUNDAY EVENING...THEN TAPER OFF OVERNIGHT AS THE LOW PRESSURE SYSTEM
PULLS OUT AND LOW-LEVEL WINDS TURN NORTH.

HIGH PRESSURE WILL BRING DRY CONDITIONS ON MONDAY...WITH INCREASING
CLOUDS ANTICIPATED ON MONDAY NIGHT. A COLD FRONT WILL MOVE THROUGH
THE REGION ON TUESDAY...BUT MODELS ARE KEEPING THE BEST FRONTOGENETIC
FORCING AND SNOW WELL SOUTH OF GRB CWA. HAVE REDUCED POPS...AND JUST
KEPT A CHANCE IN C/EC WI.

SOME WEAK LAKE EFFECT SNOW SHOWERS ARE POSSIBLE OVER FAR NC WI TUES
NGT INTO WEDS...BUT WIND TRAJECTORIES ARE WEST-NORTHWEST...SO MOST
OF THE SNOW SHOWERS SHOULD STAY IN THE UPPER PENINSULA.

HIGH PRESSURE WILL BRING PARTLY CLOUDY SKIES AND DRY CONDITIONS
WEDS NGT THROUGH THU NGT.

THE NEXT COLD FRONT AND ASSOCIATED FRONTOGENETIC FORCING IS
EXPECTED TO ARRIVE FRIDAY INTO FRIDAY NIGHT...AND THE GFS AND ECMWF
HAVE COME INTO BETTER AGREEMENT ON TIMING. RIGHT NOW...THE BEST
FORCING IS FORECAST OVER NORTHERN WI...WHERE A FEW INCHES OF SNOW
COULD OCCUR. SINCE THIS IS DAY SIX...THIS IS OBVIOUSLY A LOW
CONFIDENCE FCST. ANOTHER SYSTEM MAY BRING ADDITIONAL SNOW ACCUMS
DURING THE SAT-SUN TIME FRAME...BUT TIMING DIFFERENCES ARE EVIDENT
AT THIS TIME.

BELOW NORMAL TEMPERATURES ARE ANTICIPATED THROUGH MOST OF THE
PERIOD...AS PERIODIC FRONTAL PASSAGES REINFORCE THE CANADIAN/
MODIFIED ARCTIC AIR MASS OVER THE REGION.
&&

.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 521 PM CST SAT JAN 31 2015

MVFR CIGS WILL BE THE DOMINATE CLOUD HEIGHT OVER THE
AREA TONIGHT THROUGH SUNDAY AFTERNOON. A FEW BREAKS TO VFR CONDITIONS
ARE POSSIBLE NORTH OF A MERRILL TO MARINETTE LINE. LIGHT SNOW IS
LIKELY MAINLY SOUTH OF A WISCONSIN RAPIDS TO KEWAUNEE LINE. LOCAL
IFR CONDITIONS EXPECTED AT MANITOWOC WHERE LAKE ENHANCED SNOW IS
POSSIBLE LATE TONIGHT AND EARLY SUNDAY.
&&

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

$$

SHORT TERM.....ECKBERG
LONG TERM......KIECKBUSCH
AVIATION.......RDM