Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 290912
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
412 AM CDT FRI MAY 29 2015

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SYNOPSIS...
ISSUED AT 407 AM CDT FRI MAY 29 2015

ANOTHER WIDESPREAD SOAKING RAIN TODAY AND TONIGHT...THEN MUCH
COOLER WITH SOME FROST UP NORTH FOR THE WEEKEND.

THE SPLIT UPR FLOW ACRS NOAM WL UNDERGO SOME CONSOLIDATION THE
NEXT COUPLE DAYS AS STG NRN STREAM SHRTWV SWINGS THROUGH SRN
CANADA. BUT THE SPLIT IS EXPECTED TO RE-EMERGE NEXT WK...WITH SRN
STREAM UPR TROF POSN NR THE WEST COAST AND BROAD RIDGING OVER THE
CENTRAL CONUS.

AFTER A RATHER MILD AND HUMID DAY TDA...TEMPS WL DROP TO BLO
NORMAL LEVELS AS THE CANADIAN SHRTWV DRAGS A COOL ANTICYCLONE
SEWD INTO GREAT LAKES RGN FM NWRN CANADA...THEN WARM BACK TO ABV
NORMAL FOR THE MIDDLE TO LATTER PART OF NEXT WEEK. ANOTHER SIG
WIDESPREAD RAINFALL IS EXPECTED TDA INTO TNGT...AND MAYBE INTO
EARLY SAT OVER E-C WI. THEN SEVERAL DAYS OF DRY WX WL FOLLOW
BEFORE WE LIKELY RETURN TO A WETTER PATTERN AGAIN TOWARD THE END
OF THE FCST PERIOD. PCPN AMNTS ARE LIKELY TO BE ABV NORMAL FOR THE
PERIOD AS A WHOLE.
&&

.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 407 AM CDT FRI MAY 29 2015

BAND OF SHRA MOVG IN FM IA/SW WI WEAKENED LATE YDA EVENING...BUT
HAS REGENERATED IN THE PAST FEW HRS. BAND WL PROBABLY WEAKEN AGAIN
AS IT SHIFTS NE ACRS THE AREA. WL CARRY HIGH POPS INTO THE SW PART
OF THE FCST AREA EARLY TDA...THEN EDGE THEM BACK SOME AS THEY
SHIFT NNEWD ACRS THE AREA THIS MORNING. TOUGH TO ADD MUCH
RESOLUTION TO THE POPS LATER TDA. MODELS ALL INDICATE SOME PCPN
DURING THE LATE MORNING/AFTN. IT WL PROBABLY BE MORE SCT
HOWEVER...SO EDGED POPS DOWN SOME FOR LATER TDA. SVR RISK WL
DEPEND ON HAVING ENOUGH BREAKS IN THE PCPN/CLDS TO ALLOW THE ATM
TO DESTABILIZE. RIGHT NOW...IT/S HARD TO SEE US GETTING MUCH
SUN...SO SPC MARGINAL RISK FOR ABOUT THE SE 1/2 OF THE FCST AREA
LOOKS ON TARGET.

SHRA/TSRA SHOULD BECOME MORE NUMEROUS AGAIN LATE TDA AS THE MAIN
COLD FRONT PUSHES INTO THE AREA. SWEPT CATEGORICAL POPS SEWD ACRS
THE AREA WITH THE FRONT. EXACT TIMING OF WHEN PCPN WL OCCUR IS
DIFFICULT...AS BANDS OF SHRA/TSRA WL LIKELY BE LIFTG NEWD IN
ADVANCE OF THE FRONT...WITH ANOTHER BAND OF PCPN DEVELOPING BACK
OVER THE FRONTAL SFC. FOR THIS REASON...OPTED TO GO WITH PERIODS
OF PCPN. THE HEAVY RAIN THREAT WL BE GREATEST WITH CONVECTION
INVOF THE FRONT...AND CARRIED IT EXPLICITLY IN THE GRIDS. WL ALSO
HIGHLIGHT IN THE HWO...AND RE-ISSUE THE ESF.

WAVE DEVELOPING ALONG THE FRONT WL LIKELY SLOW IT/S EXIT FROM THE
AREA...SO BUMPED UP POPS FOR SAT MORNING FOR E-C WI. INCRG NNE
WINDS BEHIND THE FRONT COMBINED WITH LINGERING PCPN WL PROBABLY
MAKE FOR A RATHER RAW-FEELING MORNING IN E-C WI. FARTHER
NW...SKIES WL BEGIN CLEARING FM N-S AS CANADIAN HIGH PRESSURE
BUILDS TOWARD LAKE SUPERIOR.

STAYED CLOSE TO BLEND OF GUIDANCE PRODUCTS FOR TEMPS TDA AND
SAT...THOUGH LOWERED READINGS NEAR THE LAKE WHERE INCRG SLY FLOW
WL BRING LAKE-COOLED AIR INLAND. BASED MIN TEMPS TNGT ON HOURLY
GRIDS...WHICH WERE GENERATED FROM A BLEND OF GUID PRODUCTS.

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 407 AM CDT FRI MAY 29 2015

THE MAIN FCST CONCERN INITIALLY WL BE ON TEMPS AND POTENTIAL FOR
FROST/FREEZE HEADLINES THIS WEEKEND AS A COOL AIR MASS SETTLES
OVER THE GREAT LAKES. ONCE THIS COOL AIR DEPARTS...THE MAIN FCST
CONCERN BECOMES WHEN TO INTRODUCE PCPN CHCS BACK TO THE FCST
TOWARD THE MIDDLE OF NEXT WEEK.

MODELS CONT TO INDICATE A LARGE AREA OF CANADIAN HI PRES WL SETTLE
ACROSS SRN ONTARIO/NRN SECTIONS OF THE GREAT LAKES SAT NGT. MAINLY
CLEAR SKIES WITH A DRY AIR MASS AND 8H TEMPS DOWN TO +2C WL LEAD
TO A CHILLY NGT ACROSS NE WI. E-CNTRL WI LOOKS TO BE PROTECTED
FROM ANY FROST DUE TO A PERSISTENT NE WIND AT 5 TO 10 MPH THRU THE
NGT. HOWEVER...NRN WI WL SEE THE LIGHTEST WINDS BEING CLOSER TO
THE SFC HI AND THIS WOULD LEAD TO A TEMPERATURE FREE-FALL
ESPECIALLY ACROSS THE FAR NORTH. EXPECT MIN TEMPS TO DROP INTO THE
UPR 20S TO LWR 30S WITH WIDESPREAD FROST AND AN EVENTUAL HEADLINE
NEEDED. CNTRL WI TO SE TEMPS FALL INTOTHE MID TO UPR 30S WITH
PATCHY FROST ANTICIPATED.

THE SFC HI TO EXTEND FROM THE WRN GREAT LAKES NEWD TO WRN QUEBEC
ON SUNDAY AND PROVIDE FOR ANOTHER SUNNY DAY...ALTHO TEMPS WL
REMAIN BELOW NORMAL. 8H TEMPS DO BEGIN TO MODERATE A BIT (UP TO
+6C) SO EXPECT MAX TEMPS SUNDAY TO BE A FEW DEGS WARMER THAN SAT.
LOOK FOR READINGS TO TOP OUT IN THE MID 50S NEAR LAKE MI...
GENERALLY IN THE 60-65 DEG RANGE ELSEWHERE.

LITTLE CHANGE SYNOPTICALLY THRU SUNDAY NGT AS THE HI PRES REMAINS
PARKED FROM THE WRN GREAT LAKES TO QUEBEC. WL HAVE TO KEEP AN EYE
ON TEMPS ONCE AGAIN WITH RELATIVELY LIGHT WINDS EXPECTED AND
PERHAPS ONLY SOME HI CLOUDS OVERHEAD FROM PCPN LOCATED WELL TO OUR
WEST (WAA OVER THE NRN/CNTRL PLAINS). 8H TEMPS ARE NOT AS COOL AND
THE AIR MASS OVER WI IS NOT AS DRY EITHER COMPARED TO SAT NGT...
THUS MIN TEMPS SHOULD BE `MILDER` OVERALL. THAT BEING SAID...NRN
WI MAY STILL SEE READINGS FALL INTO THE 30S WITH AT LEAST PATCHY
FROST DEVELOPING.

BY THE START OF THE WORK WEEK...THE SFC HI IS FCST TO STRETCH FROM
WI TO THE CANADIAN MARITIMES/NE CONUS AND REMAIN IN FIRM CONTROL
OF NE WI WEATHER WITH MOSTLY SUNNY SKIES AND DRY AIR CONTINUING TO
BE FED INTO WI ON AN EASTERLY WIND. 8H TEMPS WL ALSO CONT TO
GRADUALLY MODERATE WHICH WOULD ADD SEVERAL DEGS TO MAX TEMPS. LOOK
FOR READINGS TO REACH AROUND 60 DEGS NEAR LAKE MI...MID TO UPR 60S
ELSEWHERE. THE SFC HI FINALLY BEGINS TO LOSE ITS GRASP OVER NE WI
ON TUE AS THE REGION GRADUALLY FALLS UNDER THE INFLUENCE OF THE
INCREASING WAA SITUATED OVER THE UPR MS VALLEY. TUE IS STILL
EXPECTED TO BE DRY...BUT THERE WL BE MORE CLOUDS AROUND AS WELL AS
WARMER TEMPS AND AN UPTICK IN MOISTURE AS DEW POINTS CLIMB ABOVE
50 DEGS. A RETURN TO SOUTH WINDS WL SEND MAX TEMPS INTO THE MID
60S LAKESIDE...LWR TO MID 70S ELSEWHERE.

THE FCST BECOMES MORE SKETCHY HEADED INTO THE MIDDLE OF NEXT WEEK
(AND BEYOND) AS THE MODELS HAVE VARIOUS SOLUTIONS WITH RESPECT TO
THE LOCATION OF A CDFNT AND THE STRENGTH OF AN UPR RDG OVER THE
E-CNTRL CONUS. THE GEM IS FLATTER WITH THIS UPR RDG...THUS
ALLOWING WAA-INDUCED/THEN CDFNT-INDUCED PCPN TO OVERSPREAD WI AS
EARLY AS TUE NGT. ON THE OTHER HAND...THE ECMWF IS THE STRONGEST
WITH THE UPR RDG INTO THE GREAT LAKES...THUS HOLDING MOST OF ANY
PCPN TO OUR NORTH AND WEST THRU THU. DUE TO AN UPR TROF MOVING
INTO THE WRN CONUS AT MID-WEEK...ONE WOULD BELIEVE THAT DOWNSTREAM
UPR RIDGING TO OCCUR...THUS HAVE LEANED THE FCST TOWARD THE ECMWF.
THE ONLY CONCERN HERE IS TUE NGT INTO WED IF THIS UPR RDG DOES NOT
BUILD QUICK ENUF (GFS)...LEADING TO A POSSIBLE MCS DEVELOPMENT
OVER THE UPR MS VALLEY THAT WOULD MOVE THRU NRN WI BEFORE
DISSIPATING. MAY KEEP A SMALL POP ACROSS THE NORTH AS A
PRECAUTION. TEMPS FOR BOTH WED AND THU WL GO ABOVE NORMAL AS
SOUTHERLY WINDS TO PREVAIL.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 407 AM CDT FRI MAY 29 2015

CIGS TDA SHOULD REMAIN PRIMARILY IN THE VFR CATEGORY DESPITE THE
SHRA...THOUGH TEMPO MVFR CONDITIONS ARE POSSIBLE IN C/N-C WI THIS
MORNING. CIGS WL FALL INTO THE LOWER-END MVFR OR IFR CATEGORY TNGT
AS THE COLD FRONT SWEEPS THROUGH THE AREA. CONDITIONS WL IMPROVE
FM N-S ON SAT.
&&

.HYDROLOGY...
ISSUED AT 407 AM CDT FRI MAY 29 2015

RECENT HEAVY RAINFALL ACROSS CENTRAL AND FAR NORTHEAST WISCONSIN
HAVE ALLOWED THE WISCONSIN RIVER AND THE MENOMINEE RIVERS TO RISE
ABOVE BANKFULL IN MANY LOCATIONS. ADDITIONAL RAINFALL OF AROUND AN
INCH ON AVERAGE IS EXPECTED TODAY INTO TONIGHT...WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. THESE PRECIPITATION AMOUNTS WOULD ONLY
SERVE TO RAISE RIVER LEVELS EVEN MORE AND PERHAPS LEAD TO MINOR
FLOODING ALONG BOTH RIVERS. PEOPLE LIVING ALONG BOTH THE WISCONSIN
AND MENOMINEE RIVERS SHOULD KEEP ABREAST OF THE LATEST WEATHER
INFORMATION AND BE PREPARED TO MOVE TO HIGHER GROUND SHOULD MINOR
FLOODING OCCUR.
&&

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

$$

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


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