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 061926
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
226 PM CDT SUN JUL 6 2014

FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 225 PM CDT SUN JUL 6 2014

CONVECTIVE TRENDS LATE THIS AFTERNOON/EVENING AND FOR MON
AFTERNOON REMAIN THE MAIN CONCERN.

THE 19Z MSAS SFC ANALYSIS INDICATED A CDFNT EXTENDED FROM THE MN
ARROWHEAD SW THRU NW WI...S-CNTRL MN INTO ERN NEBRASKA. ORGANIZED
TSTM ACTIVITY HAS HAD A TOUGH TIME GETTING GOING DUE TO A STUBBORN
STRATUS DECK WHICH HAS BLANKETED MOST OF WI ALL DAY. WHERE THE
CLOUDS HAD THINNED...STORMS HAVE TRIED TO DEVELOP OVER N-CNTRL AND
W-CNTRL WI. TEMPS UNDER THE CLOUDS WERE STUCK IN THE UPR 60S TO
MID 70S...WHILE AREAS IN THE CLEARING HAD ZOOMED INTO THE MID 80S.

THE CDFNT TO COMPLETE ITS PASSAGE THRU THE REMAINDER OF THE WI
THIS EVENING WITH SHWRS/TSTMS ENDING FROM WEST TO EAST. STILL A
CONCERN AS TO WHETHER ANY OF THESE STORMS WL BE SEVERE DUE TO THE
STRATUS CLOUDS HOLDING POTENTIALLY HIGHER INSTABILITY AT BAY.
BELEIVE THERE HAS BEEN ENUF CLEARING AHEAD OF THE CDFNT TO ALLOW
STORMS TO BUILD LATE THIS AFTERNOON...THUS AN ACTIVE EVENING AND
THE SPC SLIGHT RISK REMAINS PLAUSIBLE. ONCE THE FNT MOVES THRU...
SUBSIDENCE AND SLIGHTLY DRIER AIR SHOULD BRING DECREASING CLOUDS
FORO THE OVRNGT HOURS. DESPITE THE CLEARING TREND...ENUF LOW-
LEVEL MOISTURE LINGERS TO HOLD TEMPS UP TNGT. LOOK FOR MIN TEMPS
TO RANGE FROM THE UPR 50S NORTH TO THE MID 60S E-CNTRL WI.

DRY WEATHER TO NOT LAST LONG AS A SHORTWAVE TROF/ATTENDANT CDFNT
SWEEPS SE ACROSS THE UPR MS VALLEY AND PUSHES TOWARD THE WRN GREAT
LAKES MON AFTERNOON. WHILE THE AIR MASS WL NOT BE AS MOIST AS
SUNDAY (DEW POINTS ABOUT 10 DEGS LWR)...THE MID-LEVEL LAPSE RATES
ARE SIMILAR AND THERE IS BETTER UPR JET SUPPORT TO ADD SOME LIFT.
HAVE FOCUSED POPS FOR THE AFTERNOON HOURS AND WL HAVE TO MONITOR
STORM STRENGTH AS A FEW OF THESE STORMS COULD BECOME BORDERLINE
SEVERE. MAX TEMPS TO BE IN THE UPR 70S TO LWR 80S RANGE.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 225 PM CDT SUN JUL 6 2014

PCPN TRENDS WILL BE THE MAIN FCST CONCERN DURING THE EXTENDED PERIOD.

INTERESTING SETUP ON MONDAY NIGHT/EARLY TUESDAY...AS A STRONG S/W
TROF AND COUPLED UPPER JETS COMBINE TO INDUCE CYCLOGENESIS ALONG
A WEAK FRONTAL BOUNDARY SAGGING THROUGH NORTHERN WI. ECMWF/SREF
PAINT A BULLSEYE OF SIGNIFICANT QPF (0.50 TO 1.OO INCH) ACROSS
THE MIDDLE OF GRB CWA...WHILE THE NAM/GFS/GEM FOCUS THE MAIN AXIS
OF PCPN OVER CENTRAL WI. GIVEN THE DEGREE OF DYNAMICS...ABUNDANT
MOISTURE AND SOME ELEVATED INSTABILITY...EXPECT WIDESPREAD
SHOWERS/SCT TSTMS TO DEVELOP...WITH GOOD POTENTIAL FOR HEAVY
RAINFALL. WILL BUMP POPS UP TO CATEGORICAL ON MONDAY NIGHT.

THE FRONTAL BOUNDARY WILL LINGER OVER THE AREA INTO TUESDAY
AFTERNOON...WITH A REINFORCING SHOT OF CANADIAN AIR ARRIVING
TUESDAY NIGHT INTO EARLY WEDNESDAY. THESE FRONTS...PLUS THE TAIL
END OF A S/W TROF MOVG THROUGH NE WI...WILL KEEP A CHANCE OF
SHOWERS AND STORMS IN THE FCST THROUGH WEDNESDAY MORNING.

CANADIAN HIGH PRESSURE IS EXPECTED TO ARRIVE WEDNESDAY AFTERNOON...
THEN LINGER OVER THE WESTERN GREAT LAKES THROUGH THURSDAY NIGHT.
THIS WILL RESULT IN A DRY AND COOLER PERIOD...WITH HIGHS IN THE
70S.

AS THE CANADIAN HIGH SHIFTS EAST...RETURN FLOW AND ASSOCIATED
MOISTURE/INSTABILITY WILL MOVE BACK INTO NC/C WI BY FRIDAY
AFTERNOON...LEADING TO A CHANCE OF TSTMS. A COLD FRONT AND SOME
JET ENERGY APPROACHING FROM THE NORTHERN PLAINS MAY BRING A MORE
SIGNIFICANT ROUND OF STORMS THROUGH THE FORECAST AREA ON FRIDAY
NIGHT AND SATURDAY. ASSUMING THAT THE FRONT CLEARS THE REGION
LATER SATURDAY...PLEASANT WEATHER SHOULD RETURN FOR SUNDAY.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1236 PM CDT SUN JUL 6 2014

STRATUS DECK WITH CIGS IN THE LIFR TO MVFR RANGE TO PERSIST OVER
NE WI THRU AT LEAST MID-AFTERNOON WITH SOME CLEARING TAKING PLACE
FROM WEST TO EAST. MAIN FCST ISSUE TO BE EXTENT AND SEVERITY OF
CONVECTIVE DEVELOPMENT AHEAD OF THE MN CDFNT. AIR MASS IS STILL
QUITE UNSTABLE AHEAD OF THE FNT (ONCE THE CLOUDS THIN OUT) AND
ANTICIPATE STRONG TO SEVERE TSTMS TO DEVELOP OVER WRN WI WITH AN
E-SE MOVEMENT THRU CNTRL WI LATE THIS AFTERNOON AND ERN WI EARLY
THIS EVENING. CIGS/VSBYS SHOULD RISE INTO THE MVFR/VFR RANGE UNTIL
FROPA OCCURS...THEN CLEARING SKIES LATER THIS EVENING WL BRING VFR
CONDITIONS TO ALL NE WI TAF SITES. QUIET WEATHER TO NOT LAST LONG
AS A SHORTWAVE TROF/SECONDARY CDFNT SWING SE TOWARD THE REGION BY
MON AFTERNOON...BRINGING THE NEXT CHC FOR PCPN.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR WIZ022-
040-050.
&&

$$

SHORT TERM.....AK
LONG TERM......TSK
AVIATION.......AK





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