Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 131757
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1257 PM CDT SUN APR 13 2014

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 404 AM CDT SUN APR 13 2014

VERY ACTIVE PERIOD OF WEATHER TODAY INTO MONDAY. PRIMARY FOCUS OF
THIS PERIOD IS ADDITIONAL HEAVY RAIN POTENTIAL LATER TODAY AND
THEN RAIN CHANGING TO SNOW WITH SOME SNOW ACCUMULATION LATE
TONIGHT INTO MONDAY MORNING.

BACK EDGE OF A CLUSTER OF CONVECTION ALONG WITH A NORTHERN REGION
STRATI FORM RAIN WORKING ACROSS THE SOUTH HALF OF THE STATE THIS
MORNING AND WILL LIKELY DEPART EASTERN WISCONSIN TOWARD DAYBREAK.
MODELS IN VERY GOOD AGREEMENT WITH ANOTHER ROUND OF CONVECTION
WORKING BACK NORTH WITH THE PASSAGE OF ANOTHER WAVE. A H850 LOW
WORKS NORTHEAST ALONG A BAROCLINIC ZONE WHICH WILL EXTEND FROM
SOUTHWEST WISCONSIN TO EAST CENTRAL AREAS. DECIDED TO ISSUE A
FLOOD WATCH DUE TO THE RAIN WHICH HAS FALLEN AND ADDITIONAL RAIN
TODAY INTO TONIGHT. SEE THE HYDRO DISCUSSION FOR MORE DETAIL.

NO CHANGES TO THE RAIN CHANGING TO SNOW TREND TONIGHT. AIR COLUMN
COOLS FAST AS THE H850 LOW MOVES NORTHEAST OF THE AREA TO PRODUCE
SNOW. QUITE POSSIBLE PARTS OF NORTHEAST WISCONSIN MAY NEED A SNOW
ADVISORY LATE TONIGHT IF THE SYSTEM PCPN IS SLOWER TO DEPART
RESULTING IN MORE SNOW ACCUMULATION. WINDS WILL ALSO BE ON THE
INCREASE LATE TONIGHT WHICH WILL BRING BACK A TASTE OF WINTER TO
PART OF THE AREA.

LITTLE OR NO CHANGES TO TEMPERATURES.

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 404 AM CDT SUN APR 13 2014

MEDIUM RANGE MODELS WERE NOT IN AS CLOSE AGREEMENT AS ONE WOULD
LIKE...BUT DO SEEM TO BE A BIT BETTER THAN THEY WERE 24 HOUR AGO.
THE GENERAL IDEA IS THAT UPPER LEVEL FLOW WILL START OUT NORTH-
NORTHWEST AS THE TROUGH AXIS PASSES EAST OF WISCONSIN. FLOW THEN
IS FORECAST TO BECOME MORE ZONAL ACROSS THE WESTERN GREAT LAKES BY
MIDWEEK. AFTER THAT...AN UPPER TROUGH IS EXPECTED TO AMPLIFY OVER
THE PLAINS AND MOVE INTO THE REGION BY THE END OF THE PERIOD.

AT THE START OF THE PERIOD TEMPERATURES ARE EXPECTED TO BE MUCH
BELOW NORMAL FOR THIS TIME OF YEAR IN NORTHWEST FLOW ALOFT. THERE
WILL BE A WARMING TREND AS NORTHWEST FLOW BECOMES MORE ZONAL AND
THEN SOUTHWEST...BUT TEMPERATURES WILL LIKELY REMAIN BELOW NORMAL
THROUGHOUT THE FORECAST PERIOD.

HAVE A SMALL AREA OF CHANCE POPS IN THE EAST ON MONDAY EVENING WITH
THE DEPARTING SYSTEM...THEN DRY THROUGH AT LEAST TUESDAY. MODELS
SHOWED PRECIPITATION DEVELOPING IN THE BAROCLINIC ZONE ASSOCIATED
WITH A SYSTEM APPROACHING FROM THE WEST...BUT DO NOT ALL HAVE IT
IN THE SAME LOCATION...SO ENDED UP WITH SOME SLIGHT CHANCE POPS FOR
TUESDAY NIGHT. STUCK WITH THE BLENDED MODEL SOLUTION FOR THE REST OF
THE FORECAST PERIOD...WHICH KEEPS POPS THROUGH THE END OF NEXT WEEK.
PRECIPITATION TYPE WILL BE A BIT OF AN ISSUE...WITH MOST LOCATIONS
FALLING NEAR OR BELOW FREEZING AT NIGHT THEN WARMING UP WELL ABOVE
FREEZING DURING THE DAY. THIS RESULTED IN CHANCES FOR A VARIETY OF
PRECIPITATION TYPES.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1251 PM CDT SUN APR 13 2014

BREAK IN PCPN AND SOME DRIER AIR MOVING IN ON NORTHERLY FLOW
LEADING TO SOME IMPROVEMENT IN CIGS AND VSBYS THIS
MORNING/AFTERNOON. THIS IS TEMPORARY AS NEXT WAVE OF PCPN HEADING
NORTH AND EAST OUT OF MN AND IA. IFR CIGS TO BECOME WIDESPREAD
AGAIN LATER TODAY/TONIGHT AS RAIN REDEVELOPS. IFR CONDITIONS WITH GUSTY
NORTH WINDS WILL DEVELOP TONIGHT WITH THE RAIN CHANGING TO SNOW
FROM NORTHWEST TO SOUTHEAST MID TO LATE EVENING. SNOW EXPECTED TO
EXIT REGION MON MORNING...THOUGH NOT BEFORE LEAVING A 1 TO 3 INCH
ACCUMULATION.

&&

.MARINE...
ISSUED AT 404 AM CDT SUN APR 13 2014

SMALL CRAFT ADVISORY IN EFFECT BUT POTENTIAL FOR GALES
LATE TONIGHT INTO MONDAY MORNING. WILL LET THE DAY CREW TAKE
ANOTHER LOOK AT IT TODAY...BUT WILL MENTION GALE GUSTS IN THE TEXT
FOR NOW.
&&

.HYDROLOGY...
ISSUED AT 404 AM CDT SUN APR 13 2014

HAVE DECIDED TO ISSUE A FLOOD WATCH FOR EXCESSIVE RAIN OVER
WAUSHARA...WINNEBAGO...CALUMET AND MANITOWOC COUNTIES. THESE
COUNTIES WERE MAINLY IMPACTED BY TRAINING STORMS SATURDAY
AFTERNOON AND EVENING WHICH PRODUCED UP TO 2 INCHES OF RAINFALL
AND SOME FLOODING ISSUES. STRATIFORM RAIN PRODUCED UP TO 0.17
INCH OF RAIN AT OSH BETWEEN 1 AND 2 AM AND THIS STRATIFORM RAIN
WILL CONTINUE A FEW MORE HOURS THIS MORNING. EVEN THOUGH THEIR
WILL BE A BREAK IN THE PCPN AFTER DAYBREAK THIS MORNING...RAIN
WILL RETURN THIS AFTERNOON AND NIGHT WITH ANOTHER INCH TO 1.50
INCHES POSSIBLE OVER THE MENTION COUNTIES. THE NEXT ROUND OF
CONVECTION IS ALREADY DEVELOPING OVER THE CENTRAL PLAINS INTO
IOWA. WILL START THE WATCH NOW DUE TO THE LIKELY RUNOFF ISSUES
POSSIBLE THIS MORNING...BUT ANTICIPATE THE MAIN FLOODING AFFECTS
WILL BE LATER TODAY. ITS POSSIBLE THE WATCH MAY NEED TO BE
EXPANDED NORTH A TIER...BUT AREAS JUST NORTH MISSED THE HEAVY RAIN
ON SATURDAY.

OTHERWISE HEAVY RAIN HAS STAYED SOUTH OF THE A LINE FROM GREEN BAY
TO STEVENS POINT...SO RIVERS NORTH OF THIS LINE WILL TEND TO
GRADUALLY LOWER TODAY INTO MONDAY. MAIN STEM RIVERS INCLUDING THE
WOLF AND WISCONSIN WILL LIKELY KEEP CURRENT FLOWS DUE TO ONGOING
SNOW MELT WORKING DOWNSTREAM.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH MONDAY MORNING FOR WIZ045-048>050.
&&

$$

SHORT TERM.....TDH
LONG TERM......MG
AVIATION.......TE
MARINE.........TDH
HYDROLOGY......TDH







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