Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 261640
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1140 AM CDT FRI SEP 26 2014

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.SYNOPSIS...
ISSUED AT 340 AM CDT FRI SEP 26 2014

WARM AND DRY AUTUMN WEATHER EXPECTED THROUGH THE UPCOMING WEEKEND.

THE UPR FLOW ENTERING NOAM IS SPLIT...WITH A DEEP TROF ALONG THE
WEST COAST OF THE CONUS AND RIDGING OVER AK. DOWNSTREAM...THE FLOW
CONSOLIDATES INTO A BROAD BAND OF WESTERLIES THAT WERE ENTIRELY
ACRS CANADA. THAT LEAVES THE CENTRAL AND ERN CONUS DOMINATED BY A
LARGE SPRAWLING UPR RIDGE. THE WEST COAST TROF WL MV INLAND THE
NEXT COUPLE DAYS AND WEAKEN. THAT WL CAUSE THE UPR RIDGE TO
SHARPEN A BIT OVER THE PLAINS...ALLOWING THE WESTERLIES ACRS ERN
CANADA TO SAG SWD A BIT. A REINFORCING SHOT OF ENERGY SHOULD REACH
THE WRN TROF EARLY NEXT WEEK...CAUSING IT TO BECOME PROGRESSIVE
AGAIN. IT WL PROBABLY REACH THE FCST AREA BY LATE IN THE WEEK.

THIS IS A DRY AND VERY WARM PATTERN...WITH LITTLE CHC FOR PCPN
THE NEXT FEW DAYS. SOME SCT PCPN COULD OCCUR IF BACKDOOR COLD
FRONT GETS SHOVED INTO THE AREA AS THE ERN CANADIAN WESTERLIES
TILT A LITTLE MORE NWLY/SAG SWD EARLY NEXT WEEK...BUT THE NEXT
OPPORTUNITY FOR SIG PCPN WON/T OCCUR UNTIL THE WRN TROF ARRIVES IN
THE AREA LATE IN THE WEEK. TEMPERATURES WL BE SIGNIFICANTLY ABOVE
NORMAL DURING THE DAY...WITH THE DRY AIR STILL ALLOWING OVERNIGHT
LOWS TO FALL CLOSER TO...BUT STILL A LITTLE ABV...NORMAL.
&&

.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 340 AM CDT FRI SEP 26 2014

PRETTY QUIET WEATHER. SOME WK SHRTWVS/UPR LOWS ARE EMBEDDED
WITHIN THE LARGE SCALE UPR RIDGE ACRS THE AREA. MOISTURE ROTG ARND
THOSE FEATURES WL BRING SOME PATCHY MID CLDS TO THE AREA FM TIME
TO TIME. DESPITE THE VERY WARM TEMPS EXPECTED DURING THE
DAY...VERY GOOD RADIATIONAL COOLING CONDITIONS COMBINED WITH THE
LONGER NIGHTS NOW THAT WE ARE IN AUTUMN WL ALLOW NIGHTTIME TEMPS
TO DROP ENOUGH FOR SOME FOG TO FORM. PATCHY DENSE FOG HAS
DEVELOPED ACRS THE AREA THIS MORNING AND IS POSSIBLE AGAIN TNGT.
IN ADDITION TO LOW-LYING AREAS...PERSISTENT LGT SELY FLOW OFF LAKE
MICHIGAN WL AUGMENT LOW-LEVEL MOISTURE ENOUGH TO BRING A BIT MORE
FOG TO LAKESHORE LOCATIONS.

TEMP FCST WAS A BIT MORE DIFFICULT THAT INITIALLY EXPECTED. WE/VE
BEEN EXPECTING A GRADUAL WARMING OF A COUPLE DEGREES EACH DAY...
BUT YESTERDAYS HIGHS OVER ALL BUT N-C WI EXCEEDED WHAT WAS
ANTICIPATED. THAT RAISES QUESTIONS ABOUT HOW WARM TO GO WITH
TODAYS HIGHS. INITIAL REACTION WAS TO WANT TO RAISE THEM ABV WHAT
OCCURRED YDA GIVEN WARMING ALOFT. BUT CLD TRENDS YDA WERE ALMOST
IDEAL FOR MAXIMIZING TEMPS. SUBSTANTIAL CLOUDINESS REMAINED IN
PLACE ALL NGT TO GREATLY LIMIT THE NOCTURNAL FALL...THEN THE CLDS
DISSIPATED QUICKLY IN THE MORNING OVER THE EAST. THINKING RIGHT
NOW IS THAT WAS A ONE-TIME DEAL...AND MAXES TDA WON/T NECESSARILY
EXCEED YDA SINCE WE/LL BE OFF TO A MUCH COOLER START AFTER HAVING
CLR SKIES OVERNIGHT. STUCK CLOSE TO PREV FCST. TEMPS SAT SHOULD
WARM ANOTHER DEG OR TWO. GIVEN THE NEAR IDEAL RADIATIONAL COOLING
CONDITIONS...FELT MOST GUIDANCE MINS FOR TNGT WERE A BIT WARM.
WENT A BIT LOWER...ESP IN THE TYPICAL COOL SPOTS.

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 340 AM CDT FRI SEP 26 2014

THERE HAS BEEN ONE SIGNIFICANT CHANGE IN THE MEDIUM RANGE MODELS FOR
THIS FORECAST CYCLE...NAMELY INCREASING THE AMPLITUDE OF A DIGGING
TROUGH ACROSS THE NORTHERN GREAT LAKES ON MONDAY INTO MONDAY NIGHT.
THE GFS HAS BEEN ADVERTISING THIS FOR THE PAST COUPLE DAYS...BUT THE
ECMWF AND GEM HAVE NOW GOTTEN ON BOARD WITH THIS SOLUTION...THOUGH
THEY MOVE THE TROUGH THROUGH QUICKER THAN THE GFS.  WILL LEAN ON THE
GFS FOR THE MONDAY AND MONDAY NIGHT PERIOD.  THEN MODELS DELAY THE
ARRIVAL OF A DEEP WESTERN NOAM TROUGH MORE TOWARDS NEXT THURSDAY
WHEN A GENERAL MODEL COMPROMISE WILL WORK.

SATURDAY NIGHT THROUGH SUNDAY NIGHT...SHOULD HAVE SCATTERED TO
BROKEN CIRRUS OVERHEAD SATURDAY NIGHT FROM THE MEANDERING UPPER LOW
HANGING AROUND THE REGION.  OTHERWISE...SATURDAY NIGHT LOOKS QUIET
WITH MILD LOWS IN THE 50S.  THE CIRRUS FINALLY DEPARTS ON SUNDAY AS
THE UPPER LOW EXITS TO THE SOUTHEAST.  THOUGH WILL HAVE FILTERED
SUNSHINE...925MB TEMPS ARE IN THE UPPER TEENS...WHICH EQUATES TO
UPPER 70S FOR HIGHS.  WILL RAISE MAX TEMPS CONSEQUENTLY.  THEN A
DIGGING SHORTWAVE OVER ONTARIO WILL DRIVE A COLD FRONT TOWARDS
NORTHERN WISCONSIN LATE SUNDAY NIGHT.  SHOULD HAVE GOOD FGEN BEHIND
THE FRONT WHERE A BAND OF RAIN WILL RESIDE.  WITH THE FORCING BEHIND
THE FRONT...THE CHANCE OF RAIN WILL NOT ARRIVE UNTIL DAYBREAK.  LOWS
STILL IN THE 50S.

REST OF THE FORECAST...THE FRONT WILL MOVE ACROSS MUCH OF THE AREA
ON MONDAY AND EXIT CENTRAL WISCONSIN MONDAY NIGHT.  FGEN ALONG THE
FRONT WILL WEAKEN AS THE UPPER SUPPORT WILL SLIDE TO OUR NORTH.  BUT
LIGHT RAIN NOW LOOKS POSSIBLE EVERYWHERE ON MONDAY AND OVER CENTRAL
AND EAST-CENTRAL WISCONSIN MONDAY NIGHT.  WILL INCREASE PRECIP
CHANCES SUBSTANTIALLY.  HIGH PRESSURE RETURNS TUESDAY AND TUESDAY
NIGHT...THEN PRECIP CHANCES IMPROVE WEDNESDAY INTO THURSDAY AS THE
UPPER FLOW TURNS SOUTHWEST AHEAD OF THE LARGE WESTERN TROUGH.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1139 AM CDT FRI SEP 26 2014

WITH THE EXCEPTION OF PATCHY MVFR/IFR FOG LATER
TONIGHT TO SHORTLY AFTER SUNRISE SATURDAY MORNING...VFR CONDITIONS
TO PREVAIL THROUGH SATURDAY.

&&

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

$$

SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......MPC
AVIATION.......TDH






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