000
FXUS63 KGRB 130835
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
335 AM CDT THU JUN 13 2013

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND FRIDAY
ISSUED AT 320 AM CDT THU JUN 13 2013

SURFACE HIGH PRESSURE CENTERED JUST WEST OF ICE
COVERED HUDSON BAY WILL DROP SOUTH INTO THE GREAT LAKES BY MIDDAY
FRIDAY. THIS WILL DELIVER DRY AND COOL WEATHER TO THE AREA ALONG
WITH A STEADY BREEZE TODAY. WINDS WILL DIMINISH LATE TONIGHT AND ALLOW
TEMPERATURES TO FALL INTO THE UPPER 30S IN THE FAR NORTH. MAY NOT
BE QUITE COLD ENOUGH FOR A FROST BUT CLOSE. MOS GUIDANCE LOOKS
QUITE GOOD AND DID NOT STRAY TOO FAR FROM IT.

.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 320 AM CDT THU JUN 13 2013

THE LATEST GFS ENSEMBLE MEAN INDICATES THAT THE UPPER AIR PATTERN
WILL CONSIST OF TROUGHS OFF THE WEST COAST AND ALSO NEW ENGLAND FOR
MUCH OF THE PERIOD.  IN BETWEEN...A SUB-TROPICAL RIDGE WILL WAFFLE
AROUND FROM THE GREAT PLAINS TO THE MISSISSIPPI VALLEY.  BY THE END
OF THE PERIOD...THIS RIDGE WILL SHIFT EAST AND COULD PROVIDE A DAY
OR TWO OF MID-SUMMER WEATHER.  BUT UNTIL THIS OCCURS...PRECIP
CHANCES THIS WEEKEND ARE THE MAIN FORECAST CONCERN.  OPERATIONAL
MODELS ARE STILL HAVING TROUBLE RESOLVING A SHORTWAVE TROUGH DUE TO
DIG ACROSS THE GREAT LAKES LATE IN THE WEEKEND.  THE ECMWF HAS
MAINTAINED GOOD CONTINUITY OVER THE PAST DAY OF RUNS...SO WILL
CONTINUE TO PLACE BETS ON IT FOR MUCH OF THIS FORECAST.

FRIDAY NIGHT THROUGH SATURDAY NIGHT...SOUTHWEST FLOW WILL DEVELOP
OVER THE NORTHERN MISSISSIPPI VALLEY FRIDAY NIGHT...AHEAD OF A
CLOSED SHORTWAVE TROUGH OVER SOUTH-CENTRAL CANADA.  850-700MB THETAE
ADVECTION WILL BE INCREASING THROUGH THE NIGHT...WHICH WILL LEAD TO
THE POSSIBILITY OF SHOWERS AND TSTORMS MOVING INTO CENTRAL AND
NORTH-CENTRAL WISCONSIN...MAINLY AFTER MIDNIGHT.  THE RECEDING
AIRMASS IS PRETTY STABLE SO WILL BACK OFF OF THUNDER CHANCES...BUT
WILL INCREASE PRECIP CHANCES A LITTLE OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN.  THE WARM/MOIST ADVECTION WILL CONTINUE INTO
SATURDAY...BUT SOME GUIDANCE SUGGESTS THAT A THUNDERSTORM COMPLEX
DIVING SOUTHEAST INTO NORTHERN ILLINOIS MAY BLOCK THE MOISTURE
RETURN.  WILL LEAVE PRECIP CHANCES ALONE FOR NOW.  WEAK WARM
ADVECTION CONTINUES INTO SATURDAY NIGHT...BUT WITH SHORTWAVES
PASSING BY NORTH AND SOUTH OF THE AREA.  CURRENT POPS HANDLE THIS
WELL...AND SHOW A MINIMUM OVER NORTHEAST TO CENTRAL WISCONSIN.  THE
RIGHT REAR QUAD OF THE JET WILL BE NEARBY...SO CANNOT DIMINISH
PRECIP CHANCES TOO MUCH.  WILL JUST REDUCE THEM A BIT OVER NORTHERN
WISCONSIN.  PLENTY OF CLOUD COVER AROUND ON SATURDAY....BUT TEMPS
SHOULD STILL REACH INTO THE MIDDLE 70S.  LOWS MAINLY IN THE 50S
FRIDAY NIGHT WILL WARM SEVERAL DEGREES HEADING INTO SATURDAY NIGHT.

REST OF THE FORECAST...DRIER AIR WILL INVADE THE STATE ON
SUNDAY...WHICH IS LOOKING DRIER.  SOME POTENTIAL FOR SHOWERS OVER NE
WISCONSIN SUNDAY MORNING UNTIL THE DRIER AIR ARRIVES...SO WILL
REORIENTATE POPS A LITTLE.  THEN THE SHORTWAVE FROM SOUTH-CENTRAL
CANADA FINALLY ARRIVES LATE SUNDAY NIGHT INTO MONDAY...WHICH WILL
BRING THE NEXT CHANCE OF PRECIP.  NOT THINKING SEVERE WEATHER AT
THIS TIME...SINCE THE WAVE WILL BE WEAKENING AND PASSING THROUGH AT
THE WRONG TIME OF THE DAY.  THE CHANCE OF SHOWERS ENDS MONDAY
EVENING ONCE THE WAVE PASSES TO THE EAST...AND HIGH PRESSURE WILL
BRING SEVERAL PERIODS OF DRY CONDITIONS THROUGH THE MIDDLE OF NEXT
WEEK.  TEMPERATURES BY NEXT WEDNESDAY MAY RETURN INTO THE 80S.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1028 PM CDT WED JUN 12 2013

VFR CONDTIONS EXPECTED AS HIGH PRESSURE BUILDS INTO THE AREA.
&&

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

$$

SHORT TERM.....RDM
LONG TERM......MPC
AVIATION.......SKOWRONSKI