Area Forecast Discussion
Issued by NWS Green Bay, WI

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000
FXUS63 KGRB 281738
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1138 AM CST WED JAN 28 2015

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 310 AM CST WED JAN 28 2015

A FEW POCKETS OF CLEAR SKIES DEVELOPED OVERNIGHT AS A HIGH
PRESSURE RIDGE DRIFTED OVER THE STATE. ANY CLEARING WILL BE BRIEF
AS WIDESPREAD STRATUS OVER AREAS TO THE WEST AND AHEAD OF AN
APPROACHING TROUGH WILL SETTLE OVER THE STATE TODAY. WARM AIR
ADVECTION TODAY INTO TONIGHT WILL INCREASE THE INVERSION AND LOWER
LEVEL CLOUDS...SO LITTLE DROP OFF OF TEMPERATURES EXPECTED TONIGHT
AHEAD OF A COLD FRONT.  THIS WARM LAYER AIR ALOFT FROM 850-700 MB
PRODUCES THE PRIMARY FORECAST ISSUE TONIGHT...PCPN TYPE. BLEND OF
FORECAST SOUNDINGS SUGGEST A LIGHT MIX OF ZR-IP-S- THIS EVENING
THEN GRADUALLY CHANGE TO SNOW OVERNIGHT FROM NORTHWEST TO
SOUTHEAST WITH THE PASSAGE OF THE TROUGH AXIS AND COLD FRONT ALONG
WITH SATURATION OF THE COLUMN TO LOWER THE WET BULB TEMP. DUE TO A
RATHER DRY AIR MASS INITIALLY...THIS SYSTEM IS NOT EXPECTED TO
PRODUCE MUCH PCPN TONIGHT AND ARRIVAL OF THIS PCPN APPEARS TO BE
LATER EVENING AT THIS TIME.

SNOW WILL TAPER OFF THURSDAY MORNING AS THE SHORT WAVE DEPARTS TO
THE EAST. COLDER AIR POURING INTO THE AREA ON NORTHWEST WINDS ON
THURSDAY WILL LIKELY PRODUCE NEAR STEADY TEMPERATURES OR EARLY DAY
HIGHS. LAKE EFFECT SNOW SHOWERS WILL ALSO BE ON THE INCREASE OVER
THE LAKE SUPERIOR SNOW BELT.

.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 310 AM CST WED JAN 28 2015

UPPER LEVEL FLOW ACROSS NOAM IS FORECAST TO AMPLIFY DURING THE
PERIOD...WITH A TROUGH IN THE EAST AND A RIDGE ACROSS THE WEST.

THERE COULD BE SOME LAKE EFFECT SNOW SHOWERS IN NORTH CENTRAL
WISCONSIN FOR PART OF THURSDAY NIGHT BEHIND A DEPARTING
SYSTEM...BUT HIGH PRESSURE MOVING INTO THE AREA FOR FRIDAY WILL
LEAD TO A DRY DAY WITH UNFAVORABLE TRAJECTORIES FOR LAKE EFFECT
SNOW. MODELS SHOWED A CLIPPER SYSTEM STRIKING A GLANCING BLOW ON
FRIDAY NIGHT BUT HAVE ONLY SLIGHT CHANCE POPS GOING ACROSS THE
NORTH FOR NOW. COULD BE SOME LAKE EFFECT ON SATURDAY BEFORE
ANOTHER SYSTEM APPROACHES THE REGION. THE 00Z GFS AND 00Z ECMWF
LOOKED FAIRLY SIMILAR IN THEIR TIMING AND LOCATION OF THE SYSTEM
AS IT APPROACHES BUT THE EC HAS THE SYSTEM DEPARTING MUCH MORE
QUICKLY AND DOES NOT BRING QPF AS FAR NORTH AS THE GFS. EITHER
WAY...BEST CHANCES FOR SNOW ON SATURDAY NIGHT WOULD BE ACROSS THE
SOUTHERN HALF OF THE STATE WHILE SOME LAKE EFFECT POTENTIAL
REMAINS ACROSS NORTH CENTRAL WISCONSIN. MODEL BLEND IS CLOSER TO
THE 00Z EC SOLUTION SO HAVE POPS THROUGH SUNDAY...WITH SOME LAKE
EFFECT CHANCES IN THE NORTH AND EAST SUNDAY NIGHT. GENERALLY DRY
WEATHER CAN THEN BE EXPECTED MONDAY THROUGH TUESDAY.

MUCH COLDER AIR WILL MOVE INTO THE AREA FOR SUNDAY AND THE EARLY
PART OF THE UPCOMING WORK WEEK...WITH HIGH TEMPERATURES FROM 10
TO 20 DEGREES BELOW NORMAL.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1138 AM CST WED JAN 28 2015

SURGE OF WAA BRINGING MID/HI CLOUD DECK ACROSS NE WI THIS
AFTERNOON. IFR/LOW MVFR CIG STRATUS DECK MAY BREAK FOR A BRIEF
TIME THIS AFTERNOON INTO THE EARLY EVENING...BUT EXPECT CIGS TO
GRADUALLY DROP TOWARD IFR CONDITIONS LATER TONIGHT AS A CDFNT
MOVES SE ACROSS WI. PCPN CHCS TO GO UP TNGT AS THE FNT APPROACHES
AND FCST SNDNGS INDICATE A GOOD POTENTIAL FOR FREEZING DRIZZLE TO
OCCUR BEFORE CHANGING TO ALL SNOW AS THE COLUMN SATURATES. CIGS
SHOULD GRADUALLY IMPROVE TO MVFR CONDITIONS THU MORNING AND
EVENTUALLY VFR CONDITIONS THU AFTERNOON AS HI PRES BEGINS TO BUILD
INTO THE REGION.
&&

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

$$

SHORT TERM.....TDH
LONG TERM......MG
AVIATION.......AK






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