Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 301659
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1159 AM CDT TUE JUN 30 2015

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.SYNOPSIS...
ISSUED AT 241 AM CDT TUE JUN 30 2015

SEASONABLY COOL THE NEXT COUPLE DAYS...THEN TEMPERATURES WARMING
BACK CLOSE TO NORMAL FOR THE INDEPENDENCE DAY WEEKEND.

NWLY UPR FLOW WL CONTINUE THROUGHOUT THE FCST PERIOD...BUT WITH
SOME FLUCTUATIONS IN AMPLITUDE/STRENGTH OF THE FLOW. A FRESH SURGE
OF CANADIAN AIR INTO THE FCST AREA WL DROP TEMPERATURES TO
SEASONABLY COOL LEVELS THE NEXT COUPLE DAYS...THEN READINGS SHOULD
WARM BACK TO NR NORMAL FOR THE REST OF THE PERIOD. ONCE ANY
LINGERING SHRA/TSRA IN THE E END TDA...THE NEXT SIG CHC FOR PCPN
WL PROBABLY NOT OCCUR UNTIL LATE IN THE WEEKEND OR EARLY NEXT
WEEK. SO PCPN AMNTS FOR THE NEXT 7 DAYS WL PROBABLY COME DOWN TO
WHAT OCCURS WITH THAT EVENT.
&&

.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 241 AM CDT TUE JUN 30 2015

MAIN BAND OF SHRA/TSRA WITH FRONTAL SYSTEM CROSSING THE RGN WERE
SLOW TO EXIT THE E THIS MORNING. PCPN HAS ALSO HAD A TENDENCY TO
BACKBUILD. INSTABILITY IS LIMITED...BUT GIVEN THE REMAINING
FORCING AND LOW-LEVEL CONVERGENCE...WL NEED TO KEEP POPS IN THE
FAR E AT LEAST THROUGH THE MORNING. FINAL POPS WL BE AN ISSUANCE
TIME DECISION. SOME FG WL ALSO DEVELOP...BUT WITH PRESSURE
GRADIENT TIGHTENING FM NW-SE...WL LIKELY BE ABLE TO HANDLE IT
WITHOUT A DENSE FOG ADVISORY. GUIDANCE TEMPS FOR TDA/S HIGHS WERE
COOLER THAN PREV FCST. TRENDED FCST IN THAT DIRECTION...THOUGH WAS
NOT COMFORTABLE GOING QUITE AS COOL AS GUIDANCE INDICATED.

HIGH PRESSURE WL GRADUALLY SETTLE INTO THE RGN TNGT AND WEDNESDAY.
WITH LGT WINDS...THERE COULD BE ENOUGH LINGERING MOISTURE FOR SOME
FG AGAIN TNGT. THAT WAS ALREADY IN THE FCST...SO STUCK WITH IT. THE
NAM/S LOW-LEVEL RH LOOKED TOO HIGH ON WED...SO TRENDED TOWARD
SUNNIER CONDITIONS. EDGED MINS TNGT DOWN TOWARD A BLEND OF THE TOP
PERFORMING GUIDANCE PRODUCTS...THEN STUCK CLOSE TO THE BLEND FOR
WEDNESDAY/S HIGHS.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 241 AM CDT TUE JUN 30 2015

PREVAILING AMPLIFIED FLOW CONSISTING OF THE WRN CONUS UPR RDG/
E-CNTRL CONUS UPR TROF WL CONT THRU THE END OF THE WORK WEEK
BEFORE CHANGES BEGIN TO OCCUR THIS WEEKEND. MODELS CONT TO SHOW AN
IMPRESSIVE CLOSED UPR LOW (FOR SUMMER) TO MOVE ACROSS SRN CANADA
AND FLATTEN THE UPR RDG IN THE PROCESS. THIS PATTERN SHIFT WL TURN
THE FLOW CLOSER TO ZONAL OVER THE NRN TIER OF STATES AND ALLOW
TEMPS TO WARM TO OR SLIGHTLY ABOVE NORMAL FROM THE WEEKEND INTO
EARLY NEXT WEEK. PCPN CHCS TO BE TIED TO THE PASSAGE OF A
SHORTWAVE TROF AROUND FRI AND A CDFNT AROUND MON.

HI PRES IS FCST TO BE PARKED OVER THE WRN GREAT LAKES WED NGT AND
WL BRING MOSTLY CLEAR SKIES...LIGHT WINDS AND COOL CONDITIONS TO
NE WI. NEAR IDEAL RADIATIONAL COOLING WL SEND MIN TEMPS DOWN INTO
THE LWR TO MID 40S NORTH...UPR 40S TO LWR 50S SOUTH. IF ENUF DRY
AIR CAN ADVECT INTO THE AREA...WOULD NOT BE SHOCKED TO SEE A
COUPLE OF UPR 30S FOR TEMPS IN THE FAR NORTH. THIS SFC HI WL
STRETCH ACROSS THE ENTIRE GREAT LAKES REGION ON THU...SO
ANTICIPATE PLENTY OF SUNSHINE WITH COMFORTABLE HUMIDITY LEVELS
CONSIDERING WE ARE IN EARLY JULY. DESPITE THE COOL START TO THE
DAY...THE DRY AIR MASS OVERHEAD WL ALLOW MAX TEMPS TO REACH NEAR
70 DEGS NEAR LAKE MI...GENERALLY IN THE MID 70S ELSEWHERE.

MODELS SHOW A PRETTY STRONG SHORTWAVE DIVING SE THRU THE MIDWEST
THU NGT...HOWEVER WITH THE SFC HI ANCHORED OVER THE GREAT LAKES...
DO NOT SEE HOW ANY PCPN CAN MAKE A PUSH IN OUR DIRECTION. HAVE
REMOVED THE SLGT CHC POP FROM CNTRL WI AND KEEP SKY CONDITIONS
EITHER MOSTLY CLEAR OR PARTLY CLOUDY. THE AIR MASS OVER WI TO HAVE
MODIFIED A BIT BY THU NGT...THUS TEMPS WL NOT BE NEARLY AS COOL AS
WED NGT. INSTEAD...LOOK FOR MIN TEMPS TO RANGE FROM THE LWR 50S
NORTH...TO THE MID 50S SOUTH. QUESTIONS THEN ARISE FOR FRI AS THE
MODELS ARE IN DISPUTE WITH REGARDS TO THE STRENGTH OF A SHORTWAVE
TROF PROGGED TO MOVE INTO THE GREAT LAKES. THE TREND HAS BEEN FOR
THIS TROF TO WEAKEN...THE AFOREMENTIONED SHORTWAVE TO PASS TO OUR
SOUTH AND THE STUBBORN SFC HI TO HANG AROUND THE GREAT LAKES FOR
ONE MORE DAY. THE CONSENSUS SOLUTION MAY TRY TO PRODUCE A SLGT CHC
POP...BUT THE PCPN CHCS SEEM TO BE DWINDLING THE CLOSER TO FRI WE
GET. MAX TEMPS WL RANGE FROM THE LWR 70S NEAR LAKE MI...TO THE UPR
70S OVER CNTRL/E-CNTRL WI.

BY THE START OF THE WEEKEND...THE WRN CONUS UPR RDG TO BE IN THE
PROCESS OF BEING FLATTENED BY THE UPR LOW MOVING ACROSS SRN
CANADA. THIS WL GRADUALLY ALLOW FOR WARMER...MORE MOIST AIR MASS
TO SPREAD EAST WITH TIME. ANOTHER AREA OF HI PRES IS EXPECTED TO
MOVE INTO THE GREAT LAKES ON SAT AND BRING A DRY FCST FOR THE 4TH
OF JULY FESTIVITIES. MAX TEMPS WL BE NEAR NORMAL WHICH TRANSLATES
TO THE LWR TO MID 70S LAKESIDE...MID TO UPR 70S NORTH AND NEAR 80
DEGS SOUTH.

A MORE PRONOUNCED SOUTHERLY WIND IS FCST FOR THE LATTER HALF OF
THE WEEKEND AS THE CANADIAN UPR LOW (AND SFC LOW) REACH MANITOBA
AND A CDFNT TO STRETCH S-SW TOWARD THE CNTRL HI PLAINS. ONCE
AGAIN...THE CONSENSUS MODEL SOLUTION MAY ATTEMPT TO THROW A SLGT
CHC POP INTO THE FCST DUE TO INCREASING INSTABILITY. HOWEVER...DO
NOT SEE ANY TRIGGER (FRONTS...MID-LEVEL DISTURBANCES...JET
STREAKS...ETC.) TO SET PCPN OFF. THUS...NE WI COULD VERY WELL HAVE
A COMPLETELY DRY HOLIDAY WEEKEND. MAX TEMPS SHOULD CLIMB A DEG OR
TWO ABOVE NORMAL WITH PLENTY OF UPR 70S TO LWR 80S EXPECTED (AWAY
FROM THE LAKE).

SUNDAY NGT INTO MON APPEARS TO BE THE TIME PERIOD FOR OUR NEXT
BEST CHC OF SEEING SHWR/TSTM ACTIVITY AS THE CDFNT DRIVES EAST
INTO THE GREAT LAKES. TIMING OF THE FNT STILL UNCERTAIN AT THIS
TIME (SUNDAY NGT OR MON)...SO WL CARRY MEDIUM CHC POPS FOR BOTH
PERIODS FOR NOW. TEMPS SHOULD REMAIN NEAR NORMAL UNTIL THE FROPA
OCCURS.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1141 AM CDT TUE JUN 30 2015

ANY LINGERING MVFR CIGS SHOULD LIFT THIS AFTERNOON...WITH CLEARING
SKIES EXPECTED TONIGHT. PATCHY FOG/LOW CLOUDS MAY DEVELOP
TONIGHT IN NORTH CENTRAL WISCONSIN. ADDED SOME IFR CIGS AND MVFR
CIGS IN RHI TONIGHT. OTHERWISE...CONTINUED VFR CONDITIONS WILL
CONTINUE WEDNESDAY AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES
REGION.

&&

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

$$

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


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