Area Forecast Discussion
Issued by NWS Green Bay, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
000
FXUS63 KGRB 311750
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1250 PM CDT FRI OCT 31 2014

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.UPDATE...
ISSUED AT 949 AM CDT FRI OCT 31 2014

BRUNT OF THE SNOW FELL OVERNIGHT ACROSS THE NORTH WITH THE COMBO
SHORT WAVE TROUGH AND LAKE EFFECT. EVEN THOUGH SOME DRIER AIR IS
FILTERING INTO THE NORTHERN GREAT LAKES REGION TODAY...CAA OFF
LAKE SUPERIOR WILL CONTINUE TO GENERATE CLOUDS AND SNOW SHOWERS
ACROSS THE NORTH TODAY. AREA RADARS DO SUGGESTS ONE PERSISTENT
BAND OVER IRON COUNTY...BUT WELL WEST OF VILAS COUNTY. AT THIS
TIME...ANTICIPATE THE LAKE EFFECT SNOW ADVISORY HEADLINE WILL
STILL BE EXPIRED AT 11 AM THIS MORNING FOR VILAS...BUT ADJACENT
COUNTIES TO THE NORTH AND WEST MAY NEED TO GO LONGER.

AS FAR AS THE WINDS...MONITORING FOR ANY UPTICK WITH THE WINDS
WITH 50 KTS AT THE H850 LEVEL FROM THIS MORNINGS GRB SOUNDING. SO
FAR CURRENT HEADLINE HOLDING...SO NOT CHANGES.
&&

.SYNOPSIS...
ISSUED AT 407 AM CDT FRI OCT 31 2014

WINDY AND COLDER TODAY...BUT MODERATING TEMPERATURES BY THE
LATTER PART OF THE WEEKEND.

AMPLIFICATION OF THE LARGE SCALE PATTERN NOW WELL UNDERWAY. IT/S
EXPECTED TO PEAK TOMORROW WITH DEEP TROFS NEAR THE COASTS...AND A
SHARP FULL-LATITUDE RIDGE OVER THE PLAINS. DESPITE THE AMPLITUDE...
THE PATTERN WL REMAIN PROGRESSIVE...WITH AT LEAST A PORTION OF THE
WRN TROF REACHING THE FCST AREA NEXT WEEK.

TEMPERATURES WILL START OUT WELL BELOW NORMAL...AND IT WILL FEEL
EVEN COLDER WITH THE STRONG NORTH WINDS. BUT READINGS ARE
EXPECTED TO REBOUND BACK TO NEAR NORMAL BY SUNDAY...THEN REMAIN
AOA NORMAL NEXT WEEK. THE MAIN OPPORTUNITY FOR PCPN WL OCCUR WHEN
THE WESTERN TROF ARRIVES IN THE AREA NEXT WEEK. PCPN AMNTS ARE
LIKELY TO END UP AOB NORMAL FOR THE PERIOD.
&&

.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 407 AM CDT FRI OCT 31 2014

INTENSE UPR SHRTWV WAS CROSSING THE AREA THIS MORNING AS IT DIGS
SWD AND AMPLIFIES THE ERN CONUS LNGWV TROF. ASCENT AHEAD OF THE
SHRTWV WAS GENERATING SHOWERS...WHICH WERE MAINLY FALLING AS SNOW.
COULD STILL BE A LITTLE RAIN OVER E-C WI UNTIL THE BOUNDARY LAYER
TEMPS DROP BACK CLOSER TO FREEZING. THE PCPN WITH THE SHRTWV
SHOULD SHIFT SWD FAIRLY QUICKLY THIS MORNING...LEAVING JUST THE
LAKE-EFFECT ACRS THE AREA.

SNOWS UP NORTH GOT HEAVY FOR A TIME YDA EVENING WHEN THE STG
ASCENT WITH THE SHRTWV ENHANCED THE LAKE-EFFECT SNOW BANDS THAT
WERE FORMING. REPORTS ALWAYS A LITTLE HARD TO COME BY AT THIS
TIME OF DAY...BUT EXPECT WE/LL GET SOME REPORTS OF UP TO ARND
6 INCHES FM NRN VILAS WHEN THE COOPS REPORT. THE SHSN WL CONT
THIS MORNING...BUT WL INCREASINGLY BE HINDERED BY STG SYNOPTIC
SCALE SUBSIDENCE BEHIND THE DEPARTING SHRTWV. THAT SHOULD LEAD TO
A MORE BANDED STRUCTURE TO THE SNOWS. FLOW IN THE 925-850 MB LEANS
A LITTLE MORE NELY THAN IDEAL...FORCING THE BANDS THAT REACH VILAS
COUNTY TO TRAVERSE A LONGER OVER-LAND TRAJECTORY. ONE OR TWO
SPOTS COULD GET A FEW MORE INCHES OF ACCUMULATION...BUT THINK 1-2
INCH ADDITIONAL ACCUMULATIONS WL BE MORE COMMON. WL STICK WITH THE
ADVISORY AT THIS POINT.

WINDS HAVE ALREADY PICKED UP ACRS DOOR COUNTY...WITH GUSTS TO
46 KTS AT NPDW3. WINDS OVER THE REST OF E-C WL SHOULD INCREASE
SIGNIFICANTLY DURING THE NEXT FEW HOURS. CURRENT WIND ADVISORY
LOOKS ON TRACK...SO DON/T PLAN ON ANY CHANGES FOR IT.

FLOW ACRS LAKE SUPERIOR WL CONT TDA...BUT DECR TNGT AS THE RIDGE
AXIS NEARS. THAT MAKES CLOUD FCST A LITTLE TRICKY. GUIDANCE WAS
ALMOST UNANIMOUS IN CLEARING THINGS OUT DURING THE EVENING. NOT
SURE GETTING RID OF THE CLDS WL BE SO EASY...ESP IN THE FAR
E/NE...BUT DID GO ALONG WITH THE CLEARING TREND. THAT MEANT
DROPPING TEMPS BLO GUID...ESP OVER N-C WI WHERE A SNOW COVER NOW
EXISTS.

AFTER THE COLDER START...SATURDAY WL STILL BE A CHILLY DAY. BUT
WITH MUCH LIGHTER WINDS AND SUNSHINE...IT WON/T FEEL NEARLY AS
RAW AS TODAY.

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 407 AM CDT FRI OCT 31 2014

500MB RIDGE WILL BUILD ACROSS THE EASTERN UNITED STATES LATE IN
THE WEEKEND WITH A SOUTHWEST FLOW ALOFT BY EARLY NEXT WEEK... THEN
PATTERN SHOULD BECOME MORE ZONAL BY LATE NEXT WEEK.

TRANQUIL WEATHER PATTERN EXPECTED SATURDAY NIGHT THROUGH SUNDAY
NIGHT AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. A COLD FRONT
WILL APPROACH THE STATE FROM THE WEST ON MONDAY...THEN MOVE ACROSS
THE REGION MONDAY NIGHT AND TUESDAY. LATEST GFS/ECMWF MODEL RUN
TONIGHT WOULD SUGGEST A WAVE MOVING ALONG THE FRONT. THIS WOULD BE
SUPPORTIVE OF HIGHER CHANCES OF RAIN THAN THE CURRENT FORECAST
WOULD SUGGEST...ALONG WITH A LITTLE SLOWER EXIT OF THE SYSTEM ON
TUESDAY. TRENDED THE PRECIPITATION GRIDS WITH THIS SCENARIO IN
MIND. ANOTHER CLIPPER SYSTEM MAY AFFECT THE AREA
WEDNESDAY/WEDNESDAY NIGHT...ALTHOUGH DIFFERENCES NOTED BETWEEN THE
GFS/CANADIAN/ECMWF ON THE EXACT PATH OF THE SYSTEM. PREFER THE
ECMWF SOLUTION FOR NOW WHICH WOULD FOCUS HIGHER CHANCES ACROSS THE
NORTH DURING THIS PERIOD. ONLY MINOR ADJUSTMENTS TO MAX/MIN
TEMPERATURES DURING THE PERIOD.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1250 PM CDT FRI OCT 31 2014

CIGS WERE VFR ACROSS MOST OF THE AREA EARLY THIS AFTERNOON WITH
SOME HIGH END MVFR CIGS NEAR LAKE MICHIGAN. CIGS ACROSS THE NORTH
WERE MOSTLY MVFR DUE TO LAKE EFFECT CLOUDS AND A FEW SNOW SHOWERS
FROM LAKE SUPERIOR. OTHER THAN THAT...WINDS WERE STRONG AND GUSTY
IN THE EAST...WITH GUSTS IN EXCESS OF 40KTS IN NORTHERN DOOR
COUNTY. OTHER LOCATIONS FROM THE FOX VALLEY EAST TO LAKE MICHIGAN
HAD GUSTS GENERALLY IN THE 34 TO 38KT RANGE.

SURFACE HIGH PRESSURE FROM WESTERN ONTARIO TO KANSAS AT MIDDAY WILL
SHIFT EAST OVER THE NEXT 24 HOURS...AS AN UPPER TROUGH TO THE EAST
OF WISCONSIN CONTINUES TO MOVE AWAY AND A RIDGE APPROACHES FROM
THE WEST. THE WEAKENING SURFACE PRESSURE GRADIENT IS EXPECTED LEAD
TO A DECREASE IN WINDS LATER TODAY AND TONIGHT. CLOUDS SHOULD
DECREASE WITH THE ARRIVAL OF DRIER AIR...THOUGH THE 00Z ECMWF
INDICATED SOME HIGH RH VALUES AT 925 MB IN THE EAST THROUGHOUT THE
NIGHT. OPTED TO GO WITH THE DRYING TREND SEEN ON THE GEM-REG CLOUD
FORECAST GRAPHIC...WHICH SHOWED MOST OF THE CLOUDS EXITING THE
FORECAST AREA LATE AFTERNOON/EARLY EVENING. SOME CLOUDS WERE SHOWN
HANGING AROUND THE LAKE MICHIGAN SHORE INTO SATURDAY MORNING...BUT
CLOUDS WERE NOT AS EXTENSIVE AS WHAT THE EC 925MB RH WOULD
SUGGEST.

LIGHTER WINDS AND VFR CONDITIONS SHOULD PREVAIL DURING THE DAY ON
SATURDAY.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR WIZ022-039-040-049-
050.
&&

$$

UPDATE.........TDH
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ECKBERG
AVIATION.......MG






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.