000
FXUS63 KGRB 131152
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
652 AM CDT THU MAR 13 2014

UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND FRIDAY
ISSUED AT 358 AM CDT THU MAR 13 2014

THE MAIN FCST CONCERNS INCLUDE TEMPERATURES AND PCPN TRENDS.

STRONG WAA WILL OCCUR ACROSS THE FORECAST AREA TODAY...CAUSING
SFC TEMPS TO WARM INTO THE 30S AND LOWER 40S LATE IN THE DAY.
THE BIG QUESTION IS WHETHER THERE WILL BE ENOUGH SATURATION TO
ALLOW PCPN TO DEVELOP. UPSTREAM OBSERVATIONS WERE NOT SHOWING ANY
PCPN EARLY THIS MORNING...AND RADAR WAS ONLY INDICATING VERY WEAK
RETURNS NEAR THE MN/WI BORDER. HOWEVER...WITH COLD TEMPS IN THE
SINGLE DIGITS ABOVE AND BLO ZERO IN PLACE OVER C/NE WI...ISENT
LIFT SHOULD BE ENHANCED OVER THE COLD DOME THIS MORNING...AND BE
SUFFICIENT TO PRODUCE AT LEAST SOME FLURRIES. UPSTREAM CLOUD BASES
WERE ALSO LOWERING...WHICH SUPPORTS THE PCPN CHANCES. ANY PCPN
THAT DOES DEVELOP SHOULD SHIFT EAST BEFORE THE AIR MASS WARMS
ENOUGH TO CHANGE THE PCPN TYPE.

MILD AIR WILL REMAIN IN PLACE OVER THE CWA TONIGHT...WITH MIN
TEMPS LIKELY REMAINING WITHIN A FEW DEGREES OF THE FREEZING
MARK. A S/W TROF IS EXPECTED TO MOVE THROUGH NORTHERN WI
LATE TONIGHT...AND A COLD FRONTAL PASSAGE...SOME MID-LEVEL
FRONTOGENETIC FORCING AND THE RRQ OF AN UPPER LEVEL JET WILL
ALSO IMPACT THE CWA. EVEN THOUGH THERE IS SOME DYNAMIC FORCING...
A LACK OF MOISTURE/SATURATION SHOULD KEEP MOST OF THE FORECAST
AREA DRY. WILL KEEP A SMALL CHANCE OF SPRINKLES OR FLURRIES
OVER NC WI LATE.

AN ARCTIC COLD FRONT WILL MOVE INTO NORTHERN WI ON FRIDAY...
AND SHOULD PROVIDE ENOUGH FORCING TO PRODUCE A LIGHT MIX OF
RAIN AND SNOW THERE. HAVE BOOSTED POPS TO LIKELY OVER VILAS
COUNTY...WHERE A DUSTING TO A HALF INCH OF SNOW IS POSSIBLE
LATE IN THE AFTERNOON. ALTHOUGH CAA WILL BE ONGOING THROUGH
THE DAY...A MILD START SHOULD ALLOW MAX TEMPS TO WARM INTO
THE UPPER 30S TO MIDDLE 40S.

.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 358 AM CDT THU MAR 13 2014

MODELS STARTED OUT THIS FORECAST PERIOD WITH AN UPPER LEVEL RIDGE
IN WESTERN NOAM AND A TROUGH ACROSS THE EASTERN CONUS. THIS
PATTERN IS EXPECTED TO SHIFT AS THE RIDGE BREAKS DOWN AND A TROUGH
MOVES INTO THE WESTERN CONUS EARLY NEXT WEEK. MEDIUM RANGE MODELS
SHOWED DIFFERENCES IN THE TIMING OF THE TROUGH MOVING INTO THE
WEST AND THE LOCATION AND TIMING OF A SURFACE SYSTEM AND ITS
ASSOCIATED PRECIPITATION. AS A RESULT...CONFIDENCE IN THE FORECAST
FALLS OFF CONSIDERABLY BY THE START OF THE NEXT WORK WEEK.

HAVE A CHANCE FOR SNOW SHOWERS ON FRIDAY NIGHT IN THE WAKE OF A
DEPARTING CLIPPER SYSTEM. THERE IS A SLIGHT CHANCE FOR SNOW ON
MONDAY...BUT WOULD NOT BE SURPRISED IF SNOW NEEDED TO BE ADDED TO
SUNDAY NIGHT AND POPS INCREASED ON MONDAY AFTER THE NEXT MODEL RUN
ARRIVES SINCE THE 00Z ECMWF AND 00Z GFS BOTH HAD AN AREA OF QPF
ACROSS THE ENTIRE FORECAST AREA LATE SUNDAY NIGHT INTO MONDAY.
AFTER THAT...BLENDED MODEL SOLUTIONS LEFT MAINLY SLIGHT CHANCE
POPS THROUGH WEDNESDAY.

TEMPERATURES SHOULD BE BELOW NORMAL FOR MOST FORECAST PERIODS AS
NORTHWEST FLOW ALOFT BECOMES MORE ZONAL BY THE MIDDLE OF NEXT
WEEK. A COOLING TREND IS FORECAST THROUGH SUNDAY...WHEN HIGHS ARE
ONLY EXPECTED TO BE IN THE TEENS TO LOWER 20S...FOLLOWED BY A BIT
OF A WARM UP. HIGHS FOR TUESDAY AND WEDNESDAY SHOULD BE MOSTLY IN
THE LOWER AND MIDDLE 30S...WHICH IS ABOUT 5 TO 10 DEGREES BELOW
NORMAL FOR THIS TIME OF YEAR.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 646 AM CDT THU MAR 13 2014

THE ARRIVAL OF WARMER AIR WILL BRING INCREASED CLOUD COVER AND
SOME FLURRIES TODAY. SOME MVFR CIGS MAY DEVELOP IN C/NC WI LATER
THIS MORNING...AND IN EASTERN WI DURING THE AFTERNOON...BUT
SHOULD EVENTUALLY SHIFT EAST OF THE REGION BY EVENING. GUSTY
SW WINDS WILL DEVELOP TODAY...THEN TURN WEST LATE TONIGHT AS
A COLD FRONT MOVES THROUGH. AHEAD OF THE FRONT...STRONG LLWS
IS EXPECTED TO DEVELOP. THE LLWS SHOULD BEGIN DURING BY
MID-EVENING...AND CONTINUE UNTIL AFTER THE FRONTAL PASSAGE
OCCURS. MVFR CIGS SHOULD MOVE BACK INTO NC WI LATE TONIGHT.
&&

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

$$

SHORT TERM.....KIECKBUSCH
LONG TERM......MG
AVIATION.......KIECKBUSCH