Area Forecast Discussion
Issued by NWS Green Bay, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KGRB 310357
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1057 PM CDT SUN AUG 30 2015

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 229 PM CDT SUN AUG 30 2015

MUCH LIKE LAST NGT...THE MAIN FCST PROBLEM CENTERS ON AMOUNT/DEPTH
OF STRATUS OR FOG DEVELOPMENT TNGT/MON MORNING AS ONLY SUBTLE
SYNOPTIC CHANGES HAVE OCCURRED OVER THE PAST 24 HOURS. THE IMPACT
OF THE CLOUDS/FOG WL ALSO IMPACT TEMPS...ESPECIALLY MAX`S ON MON.

THE 19Z MSAS SFC ANALYSIS INDICATED AN AREA OF HI PRES EXTENDED
FROM THE CNTRL PLAINS NEWD THRU SRN SECTIONS OF THE GREAT LAKES.
AN AREA OF LOW PRES WAS LOCATED OVER ND/SRN MANITOBA. THE PRES
GRADIENT WAS TIGHTENING OVER THE PLAINS/UPR MIDWEST WHERE GUSTS
WERE OVER 20 MPH. VSBL SATL IMAGERY SHOWED A BAND OF LOW CLOUDS
FROM THE SRN HALF OF WI SWD...WHICH HAD IMPACTED TEMPS THIS
AFTERNOON.

ONE CHANGE SYNOPTICALLY TO BE THE LOCATION OF THE SFC HI WHICH WL
HAVE SHIFTED FARTHER EAST AND ALLOWED FOR A BIT MORE BOUNDARY
LAYER WIND TO OCCUR OVER WI TNGT. VARIABLE CLOUDS ARE EXPECTED
THIS EVENING...BUT WITH SFC WINDS BECOMING LIGHT ONCE AGAIN AND
DEW POINTS HOLDING IN THE UPR 50S TO LWR 60S..FULLY ANTICIPATE
ANOTHER ROUND OF LOW CLOUDS AND FOG TO DEVELOP LATER THIS EVENING
THRU THE OVRNGT HOURS. DO NOT BELIEVE THE FOG WL BE AS THICK AS
LAST NGT DUE TO HIGHER WINDS ALOFT...BUT STILL THINK SOME VSBYS
COULD DROP BELOW ONE MILE IN SOME LOCATIONS. MARINE FOG REMAINS A
CONCERN WITH THE MOIST AIR MOVING OVER THE COOL WATERS OF THE
LAKE (FROM STURGEON BAY SOUTH). MAY NEED TO ISSUE ANOTHER
HEADLINE LATER TNGT. MIN TEMPS TO RANGE FROM THE MID TO UPR 50S
NORTH...UPR 50S TO LWR 60S SOUTH.

EVEN THO THE SFC HI TO BE WELL TO OUR EAST ON MON...AN UPR RDG
AXIS TO STRETCH FROM THE SRN PLAINS NE TO THE GREAT LAKES AND HELP
TO KEEP DRY CONDITIONS ACROSS NE WI. MAIN QUESTIONS AGAIN FOR MON
WL BE HOW LONG THE LOW CLOUDS/FOG TO HANG AROUND AND IMPACT ON
TEMPS...ESPECIALLY WITH VERY WARM TEMPS ALOFT (8H TEMPS UP TO
ALMOST +20C). BASED ON WHAT VSBL SATELLITE IMAGERY IS SHOWING OVER
MN THIS AFTERNOON (MUCH QUICKER CLEARING)...WL TRY FOR THE
OPTIMISTIC APPROACH AND GO FOR MOSTLY SUNNY SKIES BY LATE MON
MORNING THRU THE REST OF THE DAY. THIS WOULD ALLOW FOR MAX TEMPS
TO SOAR INTO THE MID TO UPR 70S NEAR LAKE MI...LWR TO MID 80S FOR
THE REST OF THE FCST AREA.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 229 PM CDT SUN AUG 30 2015

A RETURN TO WARM AND HUMID CONDITIONS...PLUS MINOR PCPN FOR THE
MID TO LATE PART OF THE WEEK...ARE THE MAIN FCST CONCERNS.

A VERY PERSISTENT PATTERN WILL BE IN PLACE...WITH A STRONG UPPER
LEVEL RIDGE OVER THE GREAT LAKES...HIGH PRESSURE TO OUR EAST...AND
A STEADY SOUTH RETURN FLOW INTO WISCONSIN. OVERALL...THIS PATTERN
STRONGLY SUPPORTS ABOVE TO MUCH ABOVE NORMAL TEMPS...MUGGY
CONDITIONS AND PERIODS OF MARINE FOG ON LAKE MICHIGAN. PCPN WILL
BE SPOTTY AT BEST DUE TO THE PRESENCE OF THE UPPER RIDGE...BUT
WITH DEW POINTS WELL INTO THE 60S...PRECIPITABLE WATER VALUES NEAR
1.5 INCHES AND DIURNAL INSTABILITY...IT IS TOUGH TO RULE OUT
SHRA/TSRA WITH ANY WEAK FRONT OR S/W TROF THAT MOVES THROUGH.
MODELS STILL SHOW A WEAKENING FRONT MOVG INTO NORTHERN WI TUES
AFTERNOON...AND ALSO GENERALLY AGREE THAT A S/W TROF WILL TOP THE
RIDGE AND MOVE THROUGH N WI SOMETIME IN THE WED-THU PERIOD. THE
BEST CHANCE OF PCPN WOULD APPEAR TO BE LATE IN THE WEEKEND AS A
MORE SIGNIFICANT FRONTAL BOUNDARY EDGES INTO THE WESTERN GREAT
LAKES.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1056 PM CDT SUN AUG 30 2015

CLEAR SKIES AND A LIGHT SOUTHWEST WIND WILL LEAD TO THE FORMATION
OF AREAS OF IFR CIGS AND VSBYS DUE TO FOG OVERNIGHT...WHICH WILL
LINGER INTO MONDAY MORNING. SOME PATCHES OF LIFR VSBYS DEU TO
DENSE FOG ALSO EXPECTED. INCREASING SOUTHWEST WINDS MONDAY
MORNING AND RESULTANT MIXING WILL IMPROVE CONDITIONS TO VFR LEVELS
BY MONDAY LATE MORNING OR AFTERNOON.

&&

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

$$

SHORT TERM.....AK
LONG TERM......KIECKBUSCH
AVIATION.......TDH


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.