Area Forecast Discussion
Issued by NWS Green Bay, WI

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000
FXUS63 KGRB 190905
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
405 AM CDT SUN OCT 19 2014

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 404 AM CDT SUN OCT 19 2014

A CLIPPER LIKE SYSTEM WILL TRY TO PRODUCE LIGHT RAIN
SHOWERS THIS AFTERNOON OR EVENING BUT WILL BE TRYING TO SATURATE
A VERY DRY ATMOSPHERE. 00Z GRB SOUNDING ONLY HAD .28" PRECIPITABLE
WATER WITH SIMILAR VALUES AT INL AND MSP. MIGHT TURN OUT TO BE
MORE LIKE SPRINKLES FALLING FROM A MID CLOUD DECK. SOUTHERLY WINDS
AND WARM ADVECTION SHOULD MAKE FOR HIGHS CLOSE TO NORMAL TODAY.
CLOUDS SHOULD KEEP TEMPERATURES FROM FALLING MUCH TONIGHT WITH
LOWS IN THE UPPER 30S TO LOW 40S. SOME SPRINKLES ARE POSSIBLE
DURING THE EVENING. THE LEFT EXIT REGION OF AN UPPER JET MOVES
ACROSS THE AREA MONDAY AND WILL TRY TO SQUEEZE OUT SOME SPRINKLES
OR LIGHT SHOWERS FROM A DRY ATMOSPHERE. TEMPERATURES SHOULD BE
CLOSE TO NORMAL.

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 404 AM CDT SUN OCT 19 2014

AN INITIALLY AMPLIFIED...BUT PROGRESSIVE MEAN FLOW IS EXPECTED
THRU MID-WEEK BEFORE THE FLOW DE-AMPLIFIES WITH A SW CONUS UPR RDG
AND MAIN BAND OF WESTERLIES TO RUN FROM THE NRN ROCKIES E-SE TO
THE NEW ENGLAND STATES BY NEXT WEEKEND. THE MAIN FCST ISSUE TO BE
THE TIMING/STRENGTH OF A SHORTWAVE TROF THAT APPROACHES THE WRN
GREAT LAKES AROUND THU. MDLS ARE STRUGGLING WITH THIS FEATURE...
THUS PROVIDING A RANGE OF SOLUTIONS RANGING FROM DRY TO CHC POPS.
AS FOR TEMPS...ONCE WE GET PAST TUE...READINGS WL GO ABOVE NORMAL
FOR THE REMAINDER OF THE WEEK.

AN AREA OF HI PRES IS EXPECTED TO STRETCH FROM ERN ONTARIO SW THRU
WI TO THE MID-MS VALLEY MON NGT AND BEGIN TO AT LEAST BREAK UP THE
CLOUDS ACROSS CNTRL WI DURING THE OVRNGT HOURS. A N-NE WIND MAY
CONT TO BRING LAKE CLOUDS INTO ERN WI THRU THE NGT...THUS MOSTLY
CLOUDY SKIES WL HOLD. WL STILL HAVE TO WATCH THE LAKESHORE COUNTIES
FOR POSSIBLE LAKE EFFECT LIGHT SHWRS OR SPRINKLES...BUT FEEL MOST
OF THIS ACTIVITY WOULD REMAIN OFFSHORE AS TRAJS ARE NOT QUITE NE
ENUF. TEMPS MAY BE A LITTLE TRICKY OVER CNTRL WI DEPENDING ON THE
AMOUNT OF CLEARING THAT OCCURS. HAVE LOWERED VALUES A COUPLE OF
DEGS FROM THE PREVIOUS FCST...BUT KEPT THE 40 DEG WORDING OVER ERN
WI UNDER THE CLOUDS.

THE SFC RDG AXIS TO REMAIN OVER WI ON TUE WITH THE APPROACH OF AN
UPR RDG INTO THE UPR MS VALLEY. EXPECT TO SEE PLENTY OF SUNSHINE
AREA-WIDE BY THE AFTERNOON HOURS...BUT TEMPS TO REMAIN A BIT COOL
BETWEEN THE E-NE SFC WINDS AND A NORTHERLY FLOW ALOFT AHEAD OF THE
UPR RDG. LOOK FOR MAX TEMPS TO END UP IN THE 50-50 DEG RANGE OVER
MOST OF THE FCST AREA.

QUIET AND COOL CONDITIONS WL PREVAIL TUE NGT AS THE SFC RDG TO BE
SITUATED JUST TO OUR EAST AND THE UPR RDG EDGES INTO WRN WI. MAINLY
CLEAR SKIES...LIGHT WINDS AND A DRY AIR MASS SHOULD PROVIDE FOR
FAVORABLE RADIATIONAL COOLING CONDITIONS AND MOST LIKELY THE
COOLEST NGT OF THE EXTENDED FCST. MIN TEMPS TO RANGE FROM AROUND
30 DEGS NORTH...TO THE UPR 30S OVER DOOR COUNTY. THE UPR-LEVEL RDG
IS FCST TO REMAIN PARKED OVER WI THRU WED...BUT DOES BEGIN TO GET
SQUEEZED BETWEEN A CLOSED UPR LOW OVER THE MID-ATLANTIC STATES AND
A SHORTWAVE TROF PUSHING INTO THE PLAINS. STILL ANTICIPATE A SUNNY
DAY OVER NE WI WITH A SLGT BUMP UP IN TEMPS AS WINDS VEER TO THE
S-SE. AS 8H TEMPS REACH +10C...THIS SHOULD TRANSLATE TO MAX TEMPS
IN THE MID TO UPR 50S EXCEPT LWR 50S NEAR LAKE MI.

HAD HOPED TO SEE BETTER CONTINUITY DEVELOP AMONG THE MDLS WITH THE
HANDLING OF THE SHORTWAVE TROF/ASSOCIATED SFC CDFNT HEADED INTO
WED NGT...BUT ONLY THE ECMWF MADE A NOTICEABLE SHIFT IN SLOWING
THIS SYSTEM DOWN CLOSER TO THE STEADY GFS. THE MAIN PROBLEM STEMS
FROM HOW FAST TO WEAKEN THE UPR RDG OVER THE GREAT LAKES. TYPICALLY...
MDLS TEND TO WEAKEN A RDG TOO QUICKLY AND THEN BACK OFF (LIKE THE
ECMWF HAS DONE) AS WE GET CLOSER TO THE EVENT. THEREFORE...HAVE
HELD OFF ON BRINGING ANY POP WORDING INTO CNTRL WI UNTIL LATE WED
NGT AND KEPT THE EAST DRY. AS THE SHORTWAVE TROF AND CDFNT TRY TO
MOVE EAST INTO WI ON THU...THE ECMWF AND GFS TEND TO WEAKEN THE
ENTIRE SYSTEM AS ITSELF GETS SQUEEZED BETWEEN THE REMAINS OF THE
UPR RDG TO THE EAST AND A NEW UPR RDG BUILDING FROM THE SW CONUS
INTO THE CNTRL CONUS. HAVE KEPT A SLGT CHC POP OVER ALMOST ALL OF
NE WI ON THU...BUT AM NOT EXPECTING MUCH IN THE WAY OF MEASURABLE
PCPN.

THIS SYSTEM CONTS TO FIZZLE OUT OVER WI THU NGT AS UPR HEIGHTS
BUILD TOWARD THE WRN GREAT LAKES. HAVE KEPT ALL OF NE WI DRY UNDER
PARTLY CLOUDY SKIES. THE EXPANSIVE UPR RDG TO DOMINATE THE SW
QUARTER OF THE CONUS ON FRI LEAVING NE WI UNDER A GENERAL W-NW
FLOW ALOFT. MAX TEMPS ON FRI DO LOOK MILD AS 8H TEMPS WARM TO
+12C. READINGS SHOULD BE ABLE TO MAKE THE UPR 50S TO LWR 60S.

AN AREA OF LOW PRES IS THEN PROGGED TO MOVE ACROSS SRN CANADA AND
SEND A CDFNT THRU WI FRI NGT. THIS LOOKS LIKE A DRY FROPA AS MSTR
IS NEGLIGIBLE AND ALL THE FORCING TO BE LOCATED WELL TO OUR NORTH.
OTHER THAN A WIND SHIFT AND SLIGHTLY COOLER AIR ALOFT...A DRY FCST
HAS BEEN MAINTAINED...AS WELL AS THE ABOVE NORMAL TEMPS.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1056 PM CDT SAT OCT 18 2014

MAINLY VFR CONDITIONS TO PREVAIL TONIGHT INTO SUNDAY.
MID TO HIGH LEVEL CLOUDS WILL BE ON THE INCREASE LATE TONIGHT
INTO SUNDAY AS A LOW PRESSURE SYSTEM APPROACHES THE NORTHERN GREAT
LAKES REGION. ISOLATED PATCHY MVFR CIGS WITH LIGHT SHOWERS
WILL BE POSSIBLE SUNDAY AFTERNOON.
&&

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

$$

SHORT TERM.....RDM
LONG TERM......KALLAS
AVIATION.......TDH





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