000
FXUS63 KGRB 302023
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
223 PM CST SAT NOV 30 2013

FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 222 PM CST SAT NOV 30 2013

OVERALL QUIET WEATHER FOR THE REST OF THE WEEKEND WITH MINOR PCPN
CHANCES.

RADARS SHOWING WEAK RETURNS OVER THE NORTH AS A WEAK SHORT WAVE
WITH WEAK SURFACE LOW SLIDES OVER THE NORTHERN GREAT LAKES
REGION. THE LOW WILL DRAG A COLD FRONT OVER THE REGION THIS
AFTERNOON INTO EARLY EVENING EAST. DID NOTE SOME MINOR REDUCTION
IN VSBYS AT IMT AND MNM EARLIER TODAY TODAY....BUT WILL CONTINUE
THE LIGHT PCPN MENTION FAR EAST UNTIL THE FROPA EARLY EVENING.

CLOUD TRENDS LATER TODAY TONIGHT A BIT CHALLENGING. AN EARLY
EXTRAPOLATION OF THE BACK EDGE OF THE CLOUDS WITH THE WEAK SHORT
WAVE AND FRONTAL SYSTEM PASSING OVER TODAY INDICATE A DECREASING
ACROSS THE NORTH FOR THE REST OF THE AFTERNOON. HOWEVER WIDESPREAD
IFR CIGS OVER NORTHERN MINNESOTA AND SOUTH CENTRAL WITH A SAGGING
BAROCLINIC ZONE...ALSO DRIFTING SOUTH...AND SHOULD REACH DLH
AROUND 330 PM...AND THEN STARTING TO REACH THE FAR NORTH CLOSER TO
6 PM. THE ST WILL CONTINUE TO MOVE SOUTH WITH SAGGING BAROCLINIC
ZONE OVERNIGHT...SO WHATEVER CLEARING OCCURS THIS EVENING...CLOUDS
LIKELY ON THE INCREASE OVERNIGHT. SOME LIGHT FZDZ AND LIGHT SNOW
NOTED OVER CANADA...SO WILL CONTINUE THE LIGHT MIX OVER THE FAR
NORTH TONIGHT.  THE MIX SHOULD EVENTUALLY TURN TO ALL LIGHT SNOW
LATE TONIGHT AS THE COLDER AIR CAN SATURATED SAGS FURTHER SOUTH.

WEAK RIDGE OF HIGH PRESSURE WILL SETTLE OVER THE REGION SUNDAY
TO BRING MAINLY DRY CONDITIONS. CLOUDS TRENDS WILL VARY DUE TO
CAA FLOWS OFF LAKE SUPERIOR AND NEAR MICHIGAN. IN ADDITION CLOUDS
MAY PERSIST OVER WELL INLAND AREAS AS WELL DUE TO THE 850
BAROCLINIC ZONE OVER THE AREA. A FEW MODELS ARE SHOWING SOME
CONVERGENCE OVER LAKE MICHIGAN AND WILL INTRO A SMALL CHANCE OF
SNOW SHOWERS ALONG LAKE MICHIGAN WITH THE SURFACE WINDS TURN
NORTHEAST.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 222 PM CST SAT NOV 30 2013

EVOLUTION OF A DEEPENING UPPER TROUGH OVER THE WESTERN STATES FOR
THE WORK WEEK CONTINUES TO AFFECT TIMING OF WEATHER SYSTEMS.

PROGS IN GOOD AGREEMENT WITH A SUBTLE SHORT WAVE TRACKING ALONG
THE NORTHERN PLAINS IN THE ZONAL FLOW LATE SUNDAY NIGHT INTO
MONDAY NIGHT. BLEND OF THE MODELS SUGGEST PCPN WILL WORK INTO AT
LEAST MN AND NORTHWEST WI WITH THE AID OF THE RETURN WAA FLOW.

SOUTHEAST FLOW SUPPORTS CLOUDS AND PERHAPS MINOR LES ACTIVITY
ALONG LAKE MICHIGAN MONDAY INTO TUESDAY BEFORE TEMPS BEGIN TO WARM.

ISSUES THEN TURNS TO TIMING OF THE MAIN CYCLONE FOR MID WEEK WITH
THE PLACEMENT AND SPEED OF THE UPPER SUPPORT. MOST AVAILABLE
MODEL RUNS THIS MORNING SUPPORT THE GOING FORECAST. THE 12Z GFS IS
THE OUTLIER EJECTING AN UPPER LOW AHEAD OF THE DEEP TROUGH AND
DEVELOP/TRACK A FASTER SURFACE LOW OVER THE NORTHERN PLAINS
STARTING TUESDAY. MEANWHILE THE ECMWF IS SLOWER AND WARMER FOR
TUESDAY AND WEDNESDAY BEFORE LIFTING THE MAIN LOW OVER WEDNESDAY
NIGHT.

REGARDLESS OF THE TIMING...ARCTIC AIR EVENTUALLY POURS INTO THE AREA
IN THE WAKE OF THE DEEPENING SURFACE LOW FOR THE REST OF THE WEEK
BEFORE A COLD SURFACE HIGH SETTLES IN FOR THE WEEKEND.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1126 AM CST SAT NOV 30 2013

MAINLY VFR MID TO HIGH LEVEL CLOUDS EXPECTED TODAY
INTO THIS EVENING. EVEN LOCATIONS JUST TO THE WEST WITH A FROPA SO
WILL CONTINUE WITH THE VFR TREND INTO THIS EVENING. SAT IMAGERY
SHOWS WIDESPREAD IFR CIGS OVER NORTHERN MINNESOTA AND SOUTHERN
CANADA GRADUALLY WORKING SOUTHWARD. IFR CIGS ASSOCIATED WITH
BETTER SATURATION IN A H850 BAROCLINIC ZONE DROPPING SOUTHWARD
TONIGHT INTO SUNDAY. AS A RESULT WILL BRING IN IFR CONDITIONS
SOUTHWARD TO MOST LOCATIONS TONIGHT AND LINGER INTO SUNDAY
MORNING.
&&

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

$$

SHORT TERM.....JKL
LONG TERM......TDH
AVIATION.......TDH