Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 182012
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
312 PM CDT SAT OCT 18 2014

FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 312 PM CDT SAT OCT 18 2014

THE MAIN CONCERN TONIGHT...CLOUDS TRENDS AND THEIR IMPACT ON
TEMPERATURES...AND FOR TOMORROW IT IS THE CHANCE FOR PRECIPITATION.

EXTENSIVE CLOUD-COVER THIS MORNING GAVE WAY TO MOSTLY SUNNY SKIES
IN MOST LOCATIONS BY MID AFTERNOON. 12Z SOUNDING AT GRB AND
UPSTREAM AT INL AND CWPL SHOWED MOISTURE TRAPPED BELOW AN
INVERSION WITH THE INVERSION BASE BELOW 850MB. SOUNDINGS WERE THEN
PRETTY DRY UNTIL AROUND 450MB. ECMWF 925MB RH FORECAST SHOWED MUCH
DRIER AIR MOVING INTO THE STATE. THE CLOUD FORECAST ON
ENVIRONMENT CANADA WEBSITE...FROM THE GEM-REG-LAM-4D...ALSO HAD
CLOUDS DEPARTING DURING THE DAY. A WEAK MID LEVEL RIDGE
APPROACHING AND SURFACE HIGH PRESSURE MOVING INTO THE STATE SHOULD
ALLOW FOR MOSTLY CLEAR SKIES AND DECREASING WINDS DUE TO A WEAKER
SURFACE GRADIENT. THE LACK OF SIGNIFICANT CLOUD-COVER AND LITTLE
WIND SHOULD ALLOW FOR LOW TEMPERATURES WELL BELOW NORMAL. HAVE
SPLIT THE DIFFERENCE OR GONE WITH THE COLDER 12Z MAV IN MOST
LOCATIONS TONIGHT. HIGH CLOUDS MOVING INTO THE AREA AHEAD OF AN
APPROACHING MID LEVEL TROUGH AND SURFACE LOW COULD KEEP LOWS A
LITTLE WARMER THAN THE 12Z MAV LOWS.

SHOWERS ASSOCIATED WITH THE MID LEVEL TROUGH APPROACHING FROM THE
NORTHWEST WERE FORECAST BY THE MODELS TO BE MOSTLY ON THE OTHER
SIDE OF THE WISCONSIN/UPPER MICHIGAN BORDER. SO HAVE MOSTLY SLIGHT
CHANCE POPS GOING DURING THE LATTER HALF OF SUNDAY
AFTERNOON...WITH ONLY A SMALL AREA OF CHANCE POPS IN THE FAR NORTHEAST.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 312 PM CDT SAT OCT 18 2014

PCPN PCPN CHANCES SUN NGT/MON AND WED NGT/THU...AND TEMPERATURES
THROUGH THE PERIOD...ARE THE MAIN FCST CONCERNS.

A SERIES OF S/W TROFS WILL SWEEP THROUGH NE WI ON SUNDAY NIGHT AND
MONDAY...BRING A CHANCE OF SHOWERS TO MAINLY THE NE HALF OF THE
FCST AREA. DRY CONDITIONS SHOULD RETURN BY MONDAY NIGHT...BUT A
THERMAL TROF OVER THE REGION WILL HELP TO MAINTAIN MOSTLY CLOUDY
SKIES OVERNIGHT. SUNNY SKIES SHOULD RETURN ON TUESDAY...AS AN
UPPER LEVEL RIDGE AND SFC HIGH PRESSURE BECOME ESTABLISHED OVER
THE WSTRN GREAT LAKES. TEMPERATURES WILL BE NEAR SEASONAL NORMALS
DURING THIS PERIOD...WITH HIGHS IN THE UPPER 40S TO MIDDLE 50S.

PLEASANT WEATHER IS EXPECTED ON WEDNESDAY...WITH SUNSHINE AND
LIGHT SOUTH WINDS HELPING TO BOOST TEMPERATURES TO 55 TO 60
DEGREES.

AN UPPER TROF AND WEAK SFC FRONTAL BOUNDARY MAY MOVE THROUGH
THE REGION LATE WED NGT INTO THURSDAY...AS DEPICTED BY THE ECMWF
AND GEM. THE GFS/GEFS ARE MORE PERSISTENT WITH THE SFC RIDGE...
AND KEEP THE REGION GENERALLY DRY. HAVE STAYED CLOSE TO THE
MODEL BLEND...WHICH HAS SMALL POPS IN NC WI WED NGT...AND
OVER ALL BUT EC WI ON THURSDAY. CLOUD COVER MAY HOLD TEMPERATURES
BACK A BIT ON THURSDAY...BUT MOST PLACES SHOULD HAVE MILD READINGS
IN THE UPPER 50S AND LOWER 60S.

FRIDAY LOOKS LIKE A MILD DAY...WITH SW WINDS AND PARTLY CLOUDY
SKIES HELPING TO BOOST TEMPS INTO AT LEAST THE LOW TO MID 60S.
FORECAST TEMPS OF 10-14 C AT 925 MB ARE SUPPORTIVE OF EVEN WARMER
HIGHS IN THE MIDDLE 60S TO LOWER 70S...SO ADDITIONAL UPWARD
ADJUSTMENTS MAY BE NEEDED WITH SUBSEQUENT FCSTS.

SATURDAY IS A BIT OF A DILEMMA RIGHT NOW...AS THE ECMWF SHOWS
A STRONG COLD FRONTAL PASSAGE...WHILE THE GFS IS SLOWER WITH
THE FRONT AND MUCH WARMER. WILL STICK WITH THE MODEL BLEND...
WHICH OFFERS A DECENT COMPROMISE FOR TEMPS.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1256 PM CDT SAT OCT 18 2014

SKIES CLEARED ACROSS MUCH OF THE AREA LATE THIS
MORNING INTO THE EARLY PART OF THE AFTERNOON...THOUGH THERE WERE
STILL PATCHY MVFR CIGS. THERE WERE MORE WIDESPREAD MVFR CIGS
AROUND IN THE EAST AND IN NORTH CENTRAL WISCONSIN AS OF 1730Z.
EXPECT SKIES TO CLEAR ACROSS THE REST OF THE AREA LATER THIS
AFTERNOON AS SURFACE HIGH PRESSURE PUSHES EASTWARD INTO WISCONSIN
AND A WEAK MID LEVEL RIDGE APPROACHES THE STATE. 12Z SOUNDINGS FROM
KGRB/KINL/CWPL ALL HAD MOISTURE UNDER INVERSIONS WITH BASES BELOW
850MB...ALONG WITH SOME MOISTURE ABOVE 450MB...BUT PLENTY OF DRY
AIR ABOVE THE INVERSIONS. 12Z ECMWF 925MB RH FORECAST INDICATED
DRYING AT LOWER LEVELS THAT APPEARS TO BE OCCURRING. ANOTHER MID
LEVEL SHORT WAVE AND A SURFACE LOW APPROACHING THE STATE WILL
BRING AN INCREASE IN CLOUDS DURING THE MORNING ON SUNDAY WITH SOME
MVFR CIGS POSSIBLE TOWARDS MIDDAY. ANY PRECIPITATION SHOULD HOLD
OFF UNTIL THE AFTERNOON. CLOUD FORECAST GRAPHICS...FROM
ENVIRONMENT CANADA...FROM THE GEM-REG SUPPORT CLEARING TONIGHT
WITH INCREASING CLOUDS WITH...AND AHEAD OF...THE NEXT SYSTEM.
&&

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

$$

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





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