Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 070001
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
601 PM CST FRI MAR 6 2015

UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 253 PM CST FRI MAR 6 2015

SMALL PCPN CHANCES AND TEMPERATURES ARE THE MAIN FCST CONCERNS.

FIRST WEAK CLIPPER SYSTEM MOVED THROUGH THE AREA WITHOUT PRODUCING
EVEN A FLURRY TODAY...THOUGH IT PRODUCED BKN-OVC MID-LEVEL CLOUDS.
CLEARING SKIES WILL IMPACT THE REGION FOR THE REST OF THE
AFTERNOON AND EARLY EVENING BEFORE HIGH CLOUDS INCREASE AHEAD OF
THE NEXT CLIPPER. CLEAR SKIES AND DECREASING WINDS SHOULD ALLOW
TEMPS TO DROP INTO THE TEENS BEFORE MIDNIGHT...FOLLOWED BY SLOWLY
RISING TEMPS OVERNIGHT DUE TO WAA AND THE ARRIVAL OF THICKER CLOUD
COVER.

THE SECOND CLIPPER SYSTEM LOOKS MORE VIGOROUS THAN TODAY`S...AND
THE CONSENSUS OF THE MODELS IS PRODUCE SOME LIGHT QPF ACROSS
NORTHERN WI LATE TONIGHT/EARLY SATURDAY. THERE ARE INDICATIONS
THAT THE STRONGEST SHORT-WAVE ENERGY MAY SPLIT NORTH AND SOUTH OF
THE FCST AREA...AND WITH THE LOW TRACKING WELL TO OUR NORTH AND
POTENTIAL MOISTURE CONCERNS...WILL JUST KEEP CHC POPS OVER N WI
AND FLURRIES ELSEWHERE FOR NOW. WILL ADVISE THE EVENING SHIFT TO
KEEP AN EYE ON RADAR TRENDS...AS A COUPLE HOUR PERIOD OF HIGHER
POPS MAY BE NEEDED OVER THE FAR NORTH BETWEEN 10Z-14Z/SAT. ANY
ACCUMS SHOULD BE WELL UNDER AN INCH.

EXPECT PARTIAL CLEARING AFTER THE CLIPPER SHIFTS EAST DURING
THE LATE MORNING...THOUGH SOME LAKE-ENHANCED CLOUDS AND SCT
SNOW SHOWERS OR FLURRIES SHOULD AFFECT FAR NC WI INTO THE
AFTERNOON. THE PASSAGE OF THE COLD FRONT WILL SERVE TO STEEPEN
LOW-LEVEL LAPSE RATES...ALLOWING FOR DEEPER MIXING TO 850-800 MB.
THIS SHOULD ALLOW TEMPERATURES TO WARM INTO THE 30S AND LOWER 40S.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 253 PM CST FRI MAR 6 2015

MODELS CONTINUE TO SHOW A STRING OF MID-LEVEL SHORTWAVES MOVING
THROUGH SOUTHERN CANADA THIS WEEKEND. THEN WE SEE A BREAKDOWN IN
THE WEST COAST UPPER RIDGE AS WELL AS A FLATTENING AND LIFTING OF
A BROAD TROUGH OVER EASTERN CANADA. THIS WILL ALLOW FOR A MORE
MODERATE AIRMASS TO MOVE INTO THE REGION AND FOR TEMPERATURES TO
REACH AND EVEN EXCEED SEASONAL NORMS NEXT WEEK. THE MEAN FLOW WILL
BE ROUGHLY ZONAL UNTIL THE NEXT MAJOR QUESTION ABOUT A RIDGE
BUILDING OVER THE CENTRAL US COMES LATE IN THE WEEK.

SATURDAY NIGHT THROUGH SUNDAY...
CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT AS THE NEXT IN A
SERIES OF CLIPPERS SWINGS THROUGH THE REGION. A SMALL CHANCE OF
LIGHT LAKE EFFECT SHOWERS EXISTS IN EXTREME NORTH CENTRAL
WISCONSIN EARLIER IN THE NIGHT WITH A SOMEWHAT FAVORABLE
TRAJECTORY OFF A NOT COMPLETELY FROZEN OVER LAKE SUPERIOR AND
SOME SHALLOW INSTABILITY. THOSE CHANCES WILL TRAIL OFF AFTER
MIDNIGHT AS LOW LEVELS BECOME MORE STABLE. THE LEADING EDGE OF
ANY PRECIPITATION ASSOCIATED WITH THE CLIPPER MAY APPROACH CENTRAL
WISCONSIN VERY LATE IN THE NIGHT BUT SHOULD HOLD OFF UNTIL MORNING.
MODEL GUIDANCE IS COMING INTO BETTER AGREEMENT ON PRECIP POTENTIAL
WITH THIS CLIPPER THOUGH DIFFERENCES STILL REMAIN. THE NAM AND GFS
CONTINUE TO PREFER PRECIPITATION ASSOCIATED WITH THE
PRIMARY SHORTWAVE AND THE LEFT EXIT REGION OF AN UPPER JET. THE
GEM AND ECMWF FOCUS HEAVIER AMOUNTS ACROSS SOUTHERN
WISCONSIN...NORTHEASTERN IOWA...AND NORTHERN ILLINOIS ASSOCIATED
WITH THE RIGHT ENTRANCE REGION OF THE LEAD UPPER JET AND MIDLEVEL
FRONTOGENESIS. THIS...OF COURSE...PUTS MOST OF NORTHEASTERN
WISCONSIN IN A PRECIPITATION MINIMUM. THE MAIN SHORTWAVE LOOKS TO
DIG FAR ENOUGH DOWN FOR A CHANCE AT LIGHT SNOW IN NORTH CENTRAL
WISCONSIN. MEANWHILE...THE SOUTHWARD TREND OF THE QPF REGION
FAVORED BY THE EURO AND GEM HAS GIVEN CAUSE TO REDUCE POPS THERE.
WILL HEDGE FOR FUTURE CHANGES IN POSITION BY ALLOWING FOR A CHANCE
OF FLURRIES IN BETWEEN SUNDAY MORNING. TEMPS WILL BE
WARMER...THOUGH TEMPERED BY CLOUDS WITH HIGHS REACHING THE LOWER
TO MIDDLE 30S.

MONDAY THROUGH THURSDAY...
A WEAK AND VERY BRIEF SURFACE HIGH LOOKS TO SCOOT BY TO THE SOUTH
SUNDAY NIGHT. THIS WILL ALLOW FOR SOME PARTIAL CLEARING SUNDAY
NIGHT AND FOR LOWS TO AGAIN REACH THE MIDDLE TEENS TO LOWER 20S.
PARTLY CLOUDY SKIES LOOK TO PREVAIL THROUGH MONDAY AND WITH WINDS
BACKING SOUTHWEST ALONG WITH WARM 850 TEMPS...THE WARMUP WILL CONTINUE
AND SOME PLACES MAY SEE THEIR FIRST 40 DEGREE TEMPS OF 2015.

MEANWHILE...IN CANADA...ANOTHER CLIPPER MOVES IN BUT MUCH FURTHER
NORTH THAN ITS PREVIOUS BRETHREN AS THE LONGWAVE TROUGH FLATTENS
OUT. THIS SHOULD RESULT IN LITTLE IMPACT ON THE AREA BEYOND
VEERING WINDS MORE TOWARDS WESTERLY AND PERHAPS INCREASING SOME
CLOUDS IN NORTH CENTRAL WISCONSIN TUESDAY. HIGHS WILL CONTINUE
THEIR MARCH UPWARDS INTO THE MIDDLE 40S WITH A POSSIBLE 50 DEGREE
READING IN ISOLATED SPOTS OF CENTRAL WISCONSIN. IT IS WORTH NOTING
THAT THE GFS BRIEFLY FLIRTED WITH KEEPING A STRONGER WEST RIDGE-
EAST TROUGH PATTERN IN THE NORTHERN STREAM...HOLDING DOWN
TEMPERATURES MORE. THIS MORNING`S RUN OF THE GFS AND GEFS HAS
REJOINED THE REST OF THE GUIDANCE SO THIS IDEA IS DISCOUNTED...BUT
DOES STICK IN THE BACK OF THE MIND AS A REMINDER TO NOT GET
CARRIED AWAY WITH RUNAWAY WARMTH.

BEYOND TUESDAY THE GUIDANCE BEGINS TO DIVERGE...BUT WITH A LITTLE
LESS SPREAD THAN BEFORE. THOUGH THERE ARE QUESTIONS OF TIMING OF A
COLD FRONTAL MOTION THROUGH THE AREA ON WEDNESDAY...IT DOES NOT
APPEAR TO DO MUCH MORE THAN HALT THE UPWARD TREND IN TEMPS THAT
AFTERNOON. NEXT THURSDAY LOOKS A LITTLE COOLER...WITH TEMPS NEAR
NORMAL...AS WINDS TURN EASTERLY BEHIND THE FRONT.
&&

.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 601 PM CST FRI MAR 6 2015

MOSTLY VFR TONIGHT THROUGH SATURDAY THOUGH THERE WILL
BE A CHANCE OF SNOW SHOWERS WITH BRIEF MVFR LATE TONIGHT AND EARLY
SATURDAY. THE BEST CHANCE OF SNOW SHOWERS AND MVFR IS IN THE NORTH.
&&

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

$$

SHORT TERM.....KIECKBUSCH
LONG TERM......LUCHS
AVIATION.......RDM





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