Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 090911
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
411 AM CDT WED JUL 9 2014

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 411 AM CDT WED JUL 9 2014

UPPER TROF CONTINUES TO SHIFT EAST AND LOSE AMPLITUDE THIS PERIOD
WITH RETURN TO MORE WESTERLY FLOW PATTERN ON THU AS FLAT RIDGE
BUILDS IN.

AREA RADARS CONTINUE TO SHOW LIGHT SHOWER ACTIVITY MOVING THROUGH
U.P AND NORTHERN WI. QUESTION FOR THIS PERIOD IS PCPN CHANCES
TODAY. WEAK BOUNDARY PASSES THROUGH THIS MORNING...ALONG WITH LAST
PIECE OF UPPER ENERGY. COLD POOL ALOFT MOVES EAST THIS
MORNING...WITH LESS INSTABILITY AND DRIER AIR MASS THAN THAT OF
YESTERDAY. STILL WITH CYCLONIC FLOW AND STEEPER LOW LEVEL LAPSE
RATES WILL KEEP MENTION OF SHOWERS THROUGH MUCH OF DAY
PERIOD...ESPECIALLY EAST WITH AFOREMENTIONED BOUNDARY OR
DEVELOPING LAKE BREEZE. EXPECT ACTIVITY WILL BE LESS THAN TUE
WITHOUT JET SUPPORT AND SUBSIDENCE ALOFT.

QUIET WEATHER TONIGHT AND THU WITH HIGH PRESSURE MOVING IN AT THE
SURFACE. TEMPERATURES BOTH DAYS TO RUN A BIT BELOW SEASONAL NORMS.

.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 411 AM CDT WED JUL 9 2014

MEAN FLOW TO BE DICTATED BY A BUILDING UPR RDG ACROSS WRN NOAM
WHICH IN TURN WL ALLOW FOR A COOL/BROAD UPR TROF TO DEVELOP ACROSS
THE NE QUADRANT OF THE CONUS. THIS PATTERN TO BRING A NW FLOW INTO
WI BY EARLY NEXT WEEK WITH A SERIES OF CDFNTS BRINGING PCPN CHCS
TO NE WI FROM FRI THRU SUNDAY. TEMPS TO BE NEAR NORMAL THIS
WEEKEND AND THEN DROP BELOW NORMAL FOR THE START OF THE WORK WEEK.

WL BE WATCHING A SHORTWAVE TROF MOVE THRU THE NEAR ZONAL FLOW
TOWARD THE UPR MS VALLEY/MIDWEST THU NGT. AIR MASS OVER ERN WI TO
STILL BE INITIALLY DRY FROM A DEPARTED SFC HI...THUS WHILE THERE
WL BE AN INCREASE IN CLOUDS...DO NOT BELIEVE ANY PCPN WL MAKE IT
TO THE FCST AREA. THEREFORE...HAVE OPTED TO GO DRY EVERYWHERE THU
NGT. MIN TEMPS TO RANGE FROM THE LWR TO MID 50S NORTH...55-60 DEG
RANGE ELSEWHERE.

PCPN CHCS HEADED INTO FRI ARE NOT AS CLEAR-CUT AS ORIGINALLY
THOUGHT. AS THE SHORTWAVE TROF PUSHES TOWARD THE WRN GREAT LAKES...
MDLS ARE NOW HINTING AT A QPF SPLIT WITH ONE AREA OF SHWRS/TSTMS
HEADED TOWARD NRN SECTIONS OF THE GREAT LAKES ASSOCIATED WITH
STRONGER FORCING/JET STREAK AND THE OTHER AREA OF SHWRS/TSTMS
DIVING SE TOWARD THE BETTER INSTABILITY/STALLED FRONTAL BOUNDARY.
HAVE TO LWR POPS FROM THE PREVIOUS FCST WITH HIGHER VALUES OVER
THE NORTH WHO WL BE ON THE SRN FRINGE OF THE NRN PCPN AREA. SINCE
PCPN IS NOT TO BE AS WIDESPREAD...MAY HAVE TO RAISE MAX TEMPS A
FEW DEGS WITH INLAND LOCATIONS IN THE MID TO UPR 70S.

A WEAK CDFNT IS FCST TO DROP SE INTO WI FRI NGT AND WHILE THE LIFT
ASSOCIATED WITH THE FRONT IS MARGINAL...ENUF INSTABILITY AND
MOISTURE TO HELP BRING AT LEAST A SMALL CHC OF SHWRS/TSTMS TO NE
WI. THE MAIN PROBLEM FOR HIGHER POPS IS THAT THE STALLED FRONTAL
BOUNDARY TO OUR SOUTH MAY INTERCEPT INCOMING GULF MOISTURE. MORE
CLOUDS THRU THE NGT TO KEEP MIN TEMPS GENERALLY IN THE LWR TO MID
60S. AS THE UPR RDG CONTS TO BUILD ACROSS WRN NOAM AT THE START OF
THE WEEKEND...THE DEVELOPMENT OF A BROAD DOWNSTREAM UPR TROF
BEGINS TO TAKE SHAPE. AS THIS OCCURS....THE MDLS START TO STRUGGLE
WITH THE MOVEMENT OF SFC BOUNDARIES AND MID-LEVEL SHORTWAVE TROFS.
THIS BECOMES APPARENT AS EARLY AS SAT AS THE GEM RACES A SHORTWAVE
TOWARD WI...WHILE THE ECMWF HAS THIS FEATURE WEST OF LAKE WINNIPEG.
DUE TO THE WIDE RANGE OF POSSIBILITIES...FEEL IT WOULD BE PRUDENT
TO MAINTAIN A STATUS QUO APPROACH AND KEEP A SMALL POP IN THE FCST
FOR SAT. IF ENUF CLOUDS CAN STAY AWAY...MAX TEMPS AWAY FROM LAKE
MI COULD SURPASS 80S DEGS OVER MOST OF NE WI.

TIMING ISSUES CONT THRU THE END OF THE WEEKEND...THUS CONFIDENCE
IS RATHER LOW WHEN IT COMES TO PCPN CHCS. THE LOSS OF DAYTIME
HEATING AND LACK OF A SIGNIFICANT TRIGGER COULD BRING A DIMINISHED
CHC POP TO THE REGION FOR SAT NGT. HOWEVER...AN INCREASING CYCLONIC
FLOW AROUND A CLOSED UPR LOW OVER ERN MANITOBA/WRN ONTARIO MAY
ALLOW FOR A FEW SHWRS/TSTMS TO REDEVELOP ON SUNDAY. TEMPS TO REMAIN
RELATIVELY STABLE WITH MAX TEMPS SUNDAY AGAIN IN THE UPR 70S TO
AROUND 80 DEGS.

THE MAIN WEATHER FEATURE TO IMPACT OUR WEATHER EARLY NEXT WEEK WL
BE THE MOVEMENT OF THIS BROAD CLOSED UPR LOW AS IT SLOWLY DRIFTS
E-SE ACROSS ONTARIO. IT APPEARS THAT ONE MORE CDFNT TO SWING THRU
WI ON MON AND BRING YET ANOTHER CHC OF SHWRS/TSTMS TO THE REGION.
NOT SEEING MUCH FOR TUE AS THE CYCLONIC FLOW WEAKENS AND NO OTHER
TRIGGER IS APPARENT. ONE NOTICEABLE CHANGE WL BE THE STEADY DROP
IN TEMPS WITH MAX TEMPS BY TUE ONLY IN THE MID 60S FAR NORTH TO
THE LWR 70S ACROSS CNTRL/E-CNTRL WI.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 101 AM CDT WED JUL 9 2014

ISOLATED LIGHT SHOWERS CONTINUE TO SHIFT SOUTHEAST ALONG A
BOUNDARY FROM NORTH CENTRAL WI INTO THE FOX VALLEY REGION. A FEW
LOW CIGS LINGER ALONG THE LAKE SHORE. LITTLE CHANGE EXPECTED
THROUGH WED WITH UPPER LOW SLOWLY MOVING EAST OUT OF THE REGION. LOOK
FOR PATCHY FOG THROUGH THE NIGHT.
&&

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

$$

SHORT TERM.....TE
LONG TERM......KALLAS
AVIATION.......TE






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