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000
FXUS63 KGRB 180813
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
313 AM CDT TUE JUN 18 2013

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 312 AM CDT TUE JUN 18 2013

RATHER QUIET PERIOD EXPECTED THIS PERIOD. UPPER LOW AND ASSOCIATED
SHORT WAVE ACTIVITY CONTINUES TO SHIFT EAST OF THE REGION...WITH
LAST SHORT WAVE EXPECTED TO MOVE THROUGH FAR SW WI THIS MORNING.
MAIN EFFECTS FROM THAT SYSTEM WILL BE MORNING CLOUDS OVER CENTRAL WI. REST
OF REGION EXPECTED TO SEE MOSTLY SUNNY CONDITIONS...WITH THE
EXCEPTION BEING NEAR THE BAY AS COOLER AIR MASS MOVING OVER WARMER
BAY WATERS PRODUCING PATCHY STRATUS. SAT IMAGERY ALSO SHOWING SOME
PATCHY STRATUS MOVING WEST OVER CENTRAL AND SOUTHERN LAKE
MI...TOWARDS MANITOWOC. EXPECT THE CLOUDS OFF LAKE AND BAY TO MIX
OUT DURING THE FIRST HALF OF THE MORNING GIVEN DRY AIR
ALOFT...WITH MOSTLY SUNNY CONDITIONS FOR THE REMAINDER OF THE DAY.

SURFACE HIGH PRESSURE TO SHIFT EAST OVER STATE WITH WAA PATTERN
BEGINNING ON WED. TEMPS TO RUN BELOW NORMAL TODAY...WARMING TO
NEAR NORMAL ON WED.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 312 AM CDT TUE JUN 18 2013

THE MEDIUM RANGE MODELS CONTINUE TO ADVERTISE THAT NORTHWEST FLOW
WILL TRANSITION TO WEST LATER THIS WEEK AND THEN SOUTHWEST FOR THE
WEEKEND.  THIS TRANSITION WILL BRING AN ACTIVE PATTERN TO THE REGION
AS SUMMER TIME HEAT AND HUMIDITY RETURN NORTH AND SEVERAL
DISTURBANCES PASS ACROSS THE REGION.  THE ECMWF COMPARES VERY WELL
TO THE GFS ENSEMBLE MEAN AND THE GEM...SO WILL CONTINUE TO USE IT
FOR MUCH OF THIS FORECAST.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...WEAK SHORTWAVE ENERGY WILL
BE MOVING SOUTHEAST ACROSS LAKE SUPERIOR AND SOUTHERN ONTARIO
WEDNESDAY NIGHT.  THESE SHORTWAVES WILL LAY OUT A WEAK FRONT OVER
LAKE SUPERIOR WHICH COULD SPELL A FEW SHOWERS LATE...DESPITE LITTLE
INSTABILITY.  WILL KEEP A LOW END SCT MENTION.  BETTER CHANCES
APPEAR TO ARRIVE ON THURSDAY ALONG THIS BOUNDARY...WHEN THE VERY
WEAK FORCING FROM THE FRONT CAN INTERACT WITH DIURNAL INSTABILITY.
MODELS SPIT OUT ABOUT 500-700 J/KG OF ML CAPE THURSDAY AFTERNOON
THAT SHOULD BE GOOD ENOUGH FOR WIDELY SCT SHOWERS AND ISOLD
THUNDER.  MAY ALSO HAVE TO WATCH A WEAK SHORTWAVE THAT IS PROJECTED
TO MOVE OVER NORTHERN ILLINOIS AND SOUTHERN WISCONSIN...BUT RIGHT
NOW IT LOOKS A LITTLE TOO FAR SOUTH FOR ANY IMPACT IN OUR REGION.  AS
THE UPPER FLOW FLATTENS...AN 850MB WARM FRONT WILL LIFT INTO THE
NORTHERN MISSISSIPPI VALLEY THURSDAY NIGHT.  THIS LOOKS TO BE MORE
OF A PROBLEM FOR FRIDAY THOUGH THAN FOR THURSDAY NIGHT.  SO WILL TRY
TO KEEP POPS ACROSS NORTHERN WISCONSIN WHERE A FEW SHOWERS MAY STILL
BE ONGOING FROM THE DAYTIME. HIGHS IN THE UPPER 70S ON THURSDAY AND
LOWS IN THE 50S AND 60S.

REST OF THE FORECAST...THE ACTIVE PATTERN IS EXPECTED TO BEGIN ON
FRIDAY AS WARM ADVECTION CRANKS UP ALOFT AND A SURFACE WARM FRONT
LIFTS INTO SOUTHERN MINNESOTA AND IOWA.  THIS WARM FRONT IS
ANTICIPATED TO STALL OUT DURING THE WEEKEND OVER SOUTHERN OR CENTRAL
WISCONSIN.  SHOULD SEE VARIOUS CONVECTIVE COMPLEXES OVER THIS PERIOD
AS TEMPERATURES/HUMIDITY CRANK UP INTO MID-SUMMER TIME LEVELS.  SW
FLOW ALOFT WILL CONTINUE INTO EARLY NEXT WEEK.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1016 PM CDT MON JUN 17 2013

RADAR SHOWS ISOLATED SHOWERS LINGER OVER CENTRAL
WISCONSIN LATE THIS EVENING AND WILL CONTINUE TO DRIFT SOUTH OVER
CENTRAL WISCONSIN THROUGH EARLY MORNING. OTHERWISE WITH SURFACE
DEW POINTS IN THE 50S LATE THIS EVENING...AREAS OF MVFR CIGS WILL
TEND TO STICK AROUND OVERNIGHT WITH THE LINGERING MOISTURE BEFORE
DRIER AIR FROM THE NORTH CAN WORK INTO THE REGION. VFR CONDITIONS
STILL EXPECTED FOR TUESDAY.
&&

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

$$

SHORT TERM.....TE
LONG TERM......MPC
AVIATION.......TDH