Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 250914
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
414 AM CDT MON AUG 25 2014

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SYNOPSIS...
ISSUED AT 405 AM CDT MON AUG 25 2014

WARM AND HUMID WITH THUNDERSTORMS TODAY...THEN HUMIDITIES
DROPPING AND TEMPERATURES RETURNING CLOSER TO NORMAL LEVELS.

UPR PATTERN ACRS NOAM DOMINATED BY A TROF OVER THE WEST AND A
RIDGE IN THE E. STG SHRTWV EJECTING OUT OF THE WRN TROF WL FLATTEN
THE NRN PORTION OF THE ERN RIDGE EARLY IN THE FCST PERIOD...
HELPING TO LEAD THE WAY TO A MORE PROGRESSIVE LOW AMPLITUDE FLOW
ACRS SRN CANADA AND AND THE EXTREME NRN CONUS BY MID-WEEK. AS THE
THE SRN PORTION OF THE WRN TROF WL INITIALLY BE LEFT BEHIND IN A
WK SRN STREAM ACRS THE CONUS...THOUGH THAT WILL MERGE BACK INTO
THE MAIN WESTERLIES AS THEY SAG SWD DURING THE LATTER PART OF THE
FCST PERIOD.

WARM AND VERY MOIST AIR MASS INITIALLY ACRS THE AREA WL BE
REPLACED BY COOLER AND DRIER AIR EARLY IN THE FCST PERIOD. THAT WL
RESULT IN TEMPERATURES FAIRLY CLOSE TO SEASONAL NORMALS...THOUGH
WITH SOME DAY TO DAY VARIATION DUE TO CLDS/PRECIPITATION. TSTMS WL
AFFECT MUCH OF THE AREA TODAY...THEN THERE WL BE ANOTHER PRETTY
GOOD SET-UP FOR PCPN LATE IN THE WEEK AND INTO THE UPCOMING
WEEKEND...SO AMNTS WL MOST LIKELY END UP ABV NORMAL AT MOST
LOCATIONS.
&&

.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 405 AM CDT MON AUG 25 2014

MAIN FCST ISSUE IS LINING UP POPS TODAY. LINE OF STORMS THAT
DEVELOPED ALONG COLD FRONT TO OUR WEST WL CONT TO SURGE EWD AND
AFFECT MUCH OF THE FCST AREA THIS MORNING. PWATS STILL HIGH...BUT
HIGHER WINDS ALOFT WERE LEADING TO MORE RAPID STORM MOVEMENT AND
LESS EFFICIENT PRECIPITATION PRODUCTION THAT THE PAST FEW DAYS.
ALIGNMENT OF THE STORMS...HOWEVER...WAS LEADING TO TRAINING. SOME
OF THE STORMS TO THE SW HAVE PRODUCED A FEW SVR WIND GUSTS...AND
WL NEED TO CLOSELY MONITOR TO SEE IF THAT CONTS NE INTO THE FCST
AREA. IN THE GRIDS...WL HAVE HVY RAIN ATTRIBUTE WITH THE TSTMS
WHERE POPS ARE ABV 50 PCT...BUT SVR THREAT WL BE ISOLD SO WL NOT
HAVE EXPLICIT MENTION OF SVR.

LINE OF STORMS SHOULD EVENTUALLY WEAKEN IN ERN WI AND PULL OFF TO
THE NE BY LATE MORNING. BUT THE PRIMARY COLD FRONT...THOUGH
BECOMMING SOMEWHAT DIFFUSE/ILL DEFINED...WAS STILL BACK TO THE W.
ALTHOUGH CONVERGENCE ALONG THE FRONT WL NOT BE NEARLY AS STG AS
OUT TO THE W YDA...THINK IT WL STILL BE SUFFICIENT TO GENERATE
ANOTHER ROUND OF STORMS OVER MAINLY E-C WI THIS AFTN/EARLY THIS
EVENING. COVERAGE MAY REMAIN SCT THOUGH...SO DID NOT TAKE POPS
BEYOND CHC CATEGORY. THOSE STORMS MAY POSE A SVR RISK AS
WELL...THOUGH GIVEN THE WEAKER FORCING AND QUESTIONS ABOUT
DESTABILIZATION IN THE WAKE OF THE MORNING CONVECTION...WILL
HANDLE WITH JUST A MENTION IN THE HWO FOR NOW.

BOUNDARY WL CONT ON TO THE S OF THE AREA TNGT. BUT SUSPECT LOWER
DWPTS/MORE STABLE AIR WL TAKE A WHILE TO WORK INTO THE AREA. SO
LINGERED POPS ACRS THE FAR S THROUGH TNGT AS WOULD NOT BE
SURPRISED TO SEE SOME SHRA LINGER OVER THAT AREA.

WENT WITH DRY FCST FOR EARLY TUE...THEN HAD SLGT CHC POPS OVER THE
FAR S IN THE AFTN. THE MAIN RAIN CHC WL BE TO THE S...BUT AGAIN...
NOT CONFIDENT DRYING WL PROGRESS SWD AS QUICKLY AS SHOWN IN THE
MODELS.

STUCK WITH BLEND OF BEST PERFORMING GUIDANCE FOR TEMPS.

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 405 AM CDT MON AUG 25 2014

MDLS APPEAR TO BE CONSISTENT IN TAKING A PROGRESSIVE NRN STREAM
ALONG THE U.S.-CANADIAN BORDER THRU THE END OF THE WEEK WITH A
WEAKER SRN STREAM MEANDERING ACROSS THE SRN CONUS. IN BETWEEN...
THERE WL BE A SLOW-MOVING UPR TROF THAT IS EXPECTED TO REACH NE WI
LATE IN THE WEEK AND BRING ADDITIONAL PCPN CHCS TO THE REGION.
TEMPS TO SETTLE AT OR BELOW NORMAL THRU THE WORK WEEK BEFORE A
SMALL UPTICK IS NOTED NEXT WEEKEND.

THERE IS NOW MDL CONSENSUS THAT THE CDFNT WL BE ABLE TO REACH NRN
IL BEFORE PULLING UP STNRY TUE NGT. AS THIS OCCURS...AN AREA OF HI
PRES IS FCST TO PUSH TOWARD THE WRN GREAT LAKES AND HELP TO DRAW
DRIER AIR INTO NE WI. JUST DO NOT SEE ENUF OF A THREAT TO WARRANT
HANGING ON TO THE SLGT CHC POP OVER SRN SECTIONS OF THE FCST
AREA...THUS HAVE GONE DRY EVERYWHERE TUE NGT. MIN TEMPS TO
ACTUALLY BE THE TRICKY PART OF THE FCST WITH MORE CLOUDS SOUTH/
LESS CLOUDS NORTH WITH LIGHT WINDS ANTICIPATED. MAY NEED TO LOWER
VALUES FROM THE PREVIOUS FCST WITH MORE 40S NORTH TO MID 50S
E-CNTRL WI.

THIS HI PRES WL OVERSPREAD NRN SECTIONS OF THE GREAT LAKES...WHILE
ACTIVE WEATHER CONTS FROM THE CNTRL PLAINS EWD THRU THE MIDWEST
ALONG THE QUASI-STNRY FNT. ONCE AGAIN...EXPECT MORE CLOUDS ACROSS
CNTRL/E-CNTRL WI WITH MORE SUNSHINE FOR THE NORTH. TEMPS LOOK TO
BE FAIRLY UNIFORM OVER THE FCST AREA WITH UPR 60S/LWR 70S NORTH...
LWR TO MID 70S CNTRL/E-CNTRL WI.

CLASSIC BATTLE SETTING UP STARTING WED NGT BETWEEN THE INCUMBENT
DRY AIR MASS OVER NE WI AND LOW-LEVEL MOISTURE TRYING TO PUSH NWD
AS THE QUASI-STNRY FNT TRIES TO LIFT NORTH OVER THE MIDWEST. AS IS
TYPICALLY THE CASE...THE GFS IS QUICKEST IN SENDING THIS MOISTURE
NWD INTO SRN SECTIONS OF MN/WI WHILE THE OTHER MDLS FAVOR THE DRY
AIR WINNING OUT WITH PCPN JUST MOVING INTO SW WI TOWARD DAYBREAK.
PREFER THE MAJORITY HERE AND WL ONLY MENTION A MINIMAL POP FOR
CNTRL WI AFTER MIDNGT. MIN TEMPS TO RANGE FROM THE MID TO UPR 40S
NORTH (A FEW LWR 40S ARE POSSIBLE IF THE CLOUDS STAY AWAY)...TO
THE LWR TO MID 50S SRN SECTIONS.

HAVE CONTINUED TO FOLLOW THE ECMWF/S SLOWER TREND WITH THE
MOISTURE RETURNING TO WI ON THU. A SURFACE WAVE IS FCST TO DEVELOP
ALONG THE FRONTAL BOUNDARY AND HELP TO FOCUS SHWRS/TSTMS ACROSS
THE MIDWEST WITH A GRADUAL MOVEMENT OF THE PCPN INTO SW WI...
ESPECIALLY DURING THE AFTERNOON HOUR WITH THE HELP OF MODEST WAA.
HAVE KEPT CHC POPS FOR CNTRL WI...DECREASING OR NIL POPS FARTHER
NORTH AND EAST. MAX TEMPS TO GENERALLY BE IN THE UPR 60S TO LWR
70S RANGE.

THERE CONTS TO BE SOME UNCERTAINTY AS TO THE MOVEMENT/LOCATION OF
BOTH THE SURFACE WAVE AND THE NEW WRMFNT LIFTING NE TOWARD THE
GREAT LAKES THU NGT INTO FRI. THE TWIST NOW IS THAT THE GEM DOES
NOT BRING THESE FEATURES TOWARD NE WI TIL LATE ON FRI...THEREFORE
ESSENTIALLY KEEPING NE WI DRY. THIS SEEMS TOO SLOW CONSIDERING THE
SURFACE HI IS WELL TO OUR EAST AND SW WINDS ALOFT CONTS TO SEND
MOISTURE INTO WI. HAVE KEPT CHC POPS IN THE FCST FOR BOTH THU NGT
AND FRI.

UNSETTLED WEATHER TO THEN PERSIST INTO SAT AS THE INITIAL SYSTEM
TRACKS ACROSS THE GREAT LAKES...TO BE FOLLOWED BY A NRN STREAM
CDFNT PROGGED TO DROP SE INTO THE REGION. WEAK SURFACE RIDGING TO
BUILD ACROSS THE GREAT LAKES FOR SUNDAY AND PROVIDE FOR A NICER
END TO THE WEEKEND.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 405 AM CDT MON AUG 25 2014

POOR FLIGHT CONDITIONS DUE TO TSRA EXPECTED OVER MUCH OF THE AREA
EARLY THIS MORNING...AND POSSIBLE OVER E-C WI AGAIN THIS AFTN.
COULD BE SOME FG TNGT...THOUGH AT THIS POINT EXPECTING MAINLY
MVFR CONDITONS.
&&

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

$$

SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......KALLAS
AVIATION.......SKOWRONSKI





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