Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 240857
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
357 AM CDT THU APR 24 2014

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND FRIDAY
ISSUED AT 354 AM CDT THU APR 24 2014

VERY INTERESTING FORECAST SCENARIO TODAY WITH A BATTLE OF SUPER
DRY AIR TO OUR NORTH AND EAST AND STRONG LOW LEVEL WARM ADVECTION
AND UPPER SUPPORT ARRIVING FROM THE WEST.

THE VERY DRY AIR IN PLACE LAST NIGHT MADE FOR LOTS OF VIRGA UNTIL
SHORTLY AFTER MIDNIGHT WHEN SOME RAIN STARTED TO REACH THE GROUND
IN CENTRAL WISCONSIN. SIGNIFICANT EVAPORATIVE COOLING OVER NORTHCENTRAL
WISCONSIN PRODUCED A CHANGEOVER TO SNOW BETWEEN 2 AND 3 AM AND A
LIGHT COVERING OF SNOW WAS REPORTED ON THE GRASS IN RHINELANDER AT
THAT TIME.

THE LEFT EXIT REGION OF AN UPPER JET WILL APPROACH FROM THE
SOUTHWEST TODAY AND KEEP UPPER DIFFLUENT FLOW WHILE STRONG LOW
LEVEL WARM ADVECTION CONTINUES. PRECIPITATION SHOULD GRADUALLY
ARRIVE IN NORTHEAST AND EAST CENTRAL WISCONSIN THIS MORNING AS THE
VERY DRY AIR SLOWLY SATURATES. IT SHOULD BE RAIN EXCEPT OVER THE
FAR NORTHEAST WHERE THERE MAY BE SOME SNOW. AN INCH OR TWO OF SNOW
IS POSSIBLE IN GRASSY SURFACES IN THE FAR NORTH TODAY. TEMPERATURES
ABOVE FREEZING MAY CAUSE THE SNOW TO MELT WHEN THE SNOW DIMINISHES.
CLOUDY SKIES AND PRECIPITATION SHOULD KEEP TEMPERATURES ABOUT 15
DEGREES BELOW NORMAL TODAY.

ANOTHER STRONG UPPER JET APPROACHES FROM THE NORTHERN PLAINS TONIGHT
WHILE LOW LEVEL WARM ADVECTION CONTINUES. THIS SHOULD PRODUCE A
CONTINUATION OF PERIODS OF RAIN AND AND A MIX OF RAIN AND SNOW IN
THE FAR NORTH. AN INCH OR TWO OF SNOW COULD FALL NEAR THE MICHIGAN
BORDER THOUGH IT WOULD PROBABLY BE MAINLY ON THE GRASS.

THE SYSTEM SHOULD EXIT THE REGION LATE TONIGHT WITH PARTIAL
CLEARING AND GUSTY WEST WINDS FRIDAY. TEMPERATURES COULD REACH 60F
SOUTH OF HIGHWAY 29 IF THERE IS MUCH CLEARING AT ALL.

.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 354 AM CDT THU APR 24 2014

MDLS CONT TO ADVERTISE THE MEAN FLOW WL BECOME STRONGLY AMPLIFIED/
BLOCKY THIS WEEKEND AND THEN PERSIST IN THIS MANNER INTO THE MIDDLE
OF NEXT WEEK. THE MAIN WEATHER FEATURE OF INTEREST WL BE THE
DEVELOPMENT/MOVEMENT OF A CLOSED UPR LOW ACROSS THE CNTRL CONUS.
MDLS CONT TO STRUGGLE WITH THE UPR LOW`S MOVEMENT AS IT DRIFTS E-NE
EARLY NEXT WEEK. FOR NE WI...AN UNSEASONABLY COOL AND UNSETTLED
PATTERN TO BE EXPECTED AS LONG AS THIS UPR LOW IS IN THE GENERAL
VCNTY. THE COOL NGTS COULD ALSO PROVIDE SEVERAL OPPORTUNITIES FOR
SNOW ACROSS NRN WI...WHILE SEVERAL BOUTS OF RAIN COULD AGGRAVATE
HIGH RIVER/STREAM LEVELS.

NEARLY CLOSED UPR LOW IS FCST TO SLOWLY PUSH INTO SE ONTARIO FRI
NGT WITH THE WEAK CDFNT SAGGING SOUTH INTO SRN WI/NEAR THE IL
BORDER. LINGERING CYCLONIC FLOW ACROSS NRN WI FRI EVENING COULD
STILL PRODUCE AN ISOLATED RAIN OR SNOW SHWR BEFORE ENDING AFTER
MIDNGT. SOME OF THE MDLS INDICATE ENHANCED FRONTOGENTICAL FORCING
ALONG THE CDFNT WITH A CHC OF SHWRS DEVELOPING. THE BACK EDGE OF
ANY PCPN WOULD BE CLOSE TO THE SRN EDGE OF THE FCST AREA...BUT
PREFER TO KEEP THE FCST DRY FOR NOW AS HI PRES BEGINS TO BUILD
SOUTH FROM CANADA. EXPECT AT LEAST SOME CLOUDS TO HANG AROUND THRU
THE NGT WITH MIN TEMPS RANGING FROM THE MID 20S N-CNTRL...MID 30S
CNTRL/E-CNTRL WI.

THE AMPLIFICATION PROCESS BEGINS IN EARNEST ACROSS THE CONUS ON
SAT AS A DEEP UPR TROF DIGS TOWARD THE SRN ROCKIES AND DOWNSTREAM
UPR RIDGING OCCURS OVER THE E-CNTRL CONUS. NE WI TO REMAIN ON THE
SRN FRINGE OF CANADIAN HI PRES WITH A DRY E-NE WIND OVER THE AREA.
LOOK FOR A MIX OF SUN AND CLOUDS WITH MAX TEMPS FROM 45-50 DEGS
NORTH AND EAST...50 TO 55 DEGS FOR CNTRL WI.

THE DEEP UPR TROF IS PROGGED TO BECOME A CLOSED UPR LOW OVER ERN
CO SAT NGT WITH LEE-SIDE CYCLOGENESIS TAKING PLACE OVER THE CNTRL
HI PLAINS. AS THIS OCCURS...AN INCREASING SOUTHERLY LOW-LEVEL JET
OF 5O TO 60 KTS WL QUICKLY PULL GULF MOISTURE NWD THRU THE CNTRL
CONUS AND LIFT AN 8H WRMFNT TOWARD THE WI/IL BORDER BY 12Z SUNDAY.
THE COMBINATION OF INCREASED ISEN LIFT...MID-LEVEL FORCING AND THE
RIGHT ENTRANCE REGION OF THE UPR JET WL BRING A CHC OF PCPN TO
MOST OF NE WI AFTER MIDNGT. DEPENDING ON WHERE SFC TEMPS RESIDE
WHEN ANY PCPN WOULD FALL...PCPN TYPE MAY BECOME AN ISSUE ACROSS
THE NORTH WITH A MIX POSSIBLE. THE SYSTEM BECOMES NEARLY VERTICALLY
STACKED OVER THE CNTRL PLAINS BY SUNDAY AND IS NOT EXPECTED TO MOVE
MUCH AT ALL. THIS LEAVES THE WRMFNT TO OUR SOUTH WITH GULF MOISTURE
ATTEMPTING TO OVERRUN NE WI. PROBLEM IS THAT THE CANADIAN HI PRES
WL CONT TO TRY AND FEED DRY AIR INTO ERN WI. THUS...THE CLASSIC
BATTLE BETWEEN INCOMING MSTR VS. DRY AIR INTRUSION. MDLS ARE STILL
HAVING ISSUES HERE WITH WHICH ATMOSPHERIC PHENOMENA WL WIN OUT OVER
THE FCST AREA ON SUNDAY. FOR NOW...PREFER TO FAVOR HIGHEST CHC POPS
OVER CNTRL WI AND TIER POPS DOWN TO LESS THAN SLGT CHC FOR FAR NE
WI. ANY MIXED PCPN SHOULD TRANSITION TO ALL LIQUID BY MID-MORNING
AS TEMPS WARM.

THE BATTLE BETWEEN INCOMING MOISTURE AND DRY AIR FEED TO PERSIST
THRU MON AS THE STACKED SYSTEM CRAWLS ACROSS THE CNTRL PLAINS AND
THE NOW QUASI-STNRY FNT WAVERS OVER NRN IL. UNTIL THIS BATTLE HAS
A CLEAR-CUT WINNER (WHICH THE MDLS STILL DISPUTE)...WL CONT THE
TREND OF CARRYING HIGHEST CHC POPS OVER CNTRL WI AND LOWEST SLGT
CHC POP OVER FAR NE WI. MAX TEMPS FOR EARLY NEXT WEEK ARE STILL
EXPECTED TO AVERAGE 10 TO 20 DEGS BELOW NORMAL.

FCST BECOMES EVEN MORE COMPLICATED/COMPLEX HEADED TOWARD THE MIDDLE
OF NEXT WEEK AS THE MDLS NOW TRY TO ROTATE A PIECE OF UPR LEVEL
ENERGY W-SW TOWARD THE GREAT LAKES FROM A SYSTEM IMPACTING THE
CANADIAN MARITIMES. EXACTLY WHAT AFFECT THIS ENERGY HAS ON THE UPR
LOW EDGING ACROSS THE MID-MS VALLEY IS UNKNOWN AT THIS TIME. THE
SAFEST THING TO DO IS TO FOLLOW THE CONSENSUS SOLUTION WHICH KEEPS
THE WEATHER UNSETTLED OVER NE WI FOR BOTH TUE AND WED.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1020 PM CDT WED APR 23 2014

NEED TO SLOW THE EWD ADVANCE OF THE PCPN AGAIN AS VERY DRY AIR
CONTS TO FEED IN FM THE E. THAT AS ALSO MAINTAINING CIGS IN VFR
CATEGORY EVEN WHERE PCPN WAS OCCURRING. WL ADJUST 06Z TAFS
ACCORDINGLY. WL MAINTAIN LLWS TNGT INTO TOMORROW.
&&

.HYDROLOGY...ABOUT AN INCH OF RAIN AND MELTED SNOW IS EXPECTED
OVER CENTRAL AND NORTHCENTRAL WISCONSIN BETWEEN THIS MORNING AND
FRIDAY MORNING...WITH AROUND A HALF INCH IN EAST CENTRAL AND
NORTHEAST WISCONSIN. THIS WILL LIKELY CAUSE SOME RIVERS AND STREAM
TO SLOWLY RISE THOUGH MOST SHOULD REMAIN WITHIN THEIR BANKS. IF
YOU LIVE NEAR A RIVER OR STREAM LISTEN FOR LATER WEATHER
INFORMATION.

&&





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

$$

SHORT TERM.....RDM
LONG TERM......KALLAS
AVIATION.......SKOWRONSKI






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