FXUS63 KGRB 091313 AAC
AFDGRB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREEN BAY WI
713 AM CST WED DEC 9 2009
.UPDATE...UPR DEFORMATION ZONE STILL CONTRACTING MAIN HEAVY SNOW
BAND IN ERN WI. THIS SHOULD BE THE LAST REAL HEAVY SNOW WITH THE
SYSTEM. GIVEN HOW UPR DYNAMICS ARE SPENT...THINK WE WL SEE SNOW
BAND JUST SLOWLY COLLAPSE ACRS THE AREA RATHER THAN HAVING SNOW
BAND MOVE OUT OR DIMINISH IN A MORE ORGANIZED FASHION.
4 AM ZONES HAD ADDITIONAL ACCUMULATION WORDING...SO WILL NEED TO
UPDATE THEM. STORM TOTALS STILL LOOK ON TRACK...SO DON/T PLAN ANY
CHANGES.
GRB ASOS NOW G38 KTS. RUC SUGGESTS THAT COULD STILL INCREASE
FURTHER DURING THE NEXT COUPLE HOURS.
UPDATED PRODUCE SUITE WL BE OUT WITHIN THE HOUR.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 604 AM CST WED DEC 9 2009...
UPDATE...HEAVIEST SNOW BAND DIMINISHED A BIT IN THE PAST
HOUR...BUT SEEMS TO BE RE-ORGANIZING. BAND SEEMS TO BE GETTING
COMPACTED TOGETHER IN DEFORMATION ZONE. THINK WE WILL HAVE THIS
ONE LAST PULSE UP IN THE SNOW...THEN IS SHOULD START SLOW BUT
STEADY DOWNWARD TREND IN INTENSITY. UPPER DYNAMICS PROBABLY JUST
ABOUT SPENT.
HAD BRIEF BLIZZARD CONDITIONS IN GRB...AND HAVEN/T REALLY REACHED
CRITERIA ELSEWHERE. ALSO HAVE BEEN GETTING INCH PER HOUR SNOWS
WITH VSBYS OF 3/4 TO 1SM. HAVE SEEN THIS A FEW TIMES BEFORE IN
STORMS GENERATING THE HEAVY WET PACKING-TYPE SNOW.
NOT AT ALL DISSAPPOINTED THAT WE HAVE THE BLIZZARD WARNING RUNNING
THOUGH...AS THIS STORM IS REALLY CAUSING HAVOC. WPS INDICATING
10-12 PCT OF CUSTOMERS IN STURGEON BAY AND MARINETTE AREAS WERE
WITHOUT POWER.
ONE TROUBLING DEVELOPMENT HAS OCCURRED ON THE LATEST RUC. WAS
PREVIOUSLY THINKING CYCLONE CENTER WOULD GET IN CLOSE ENOUGH TO
ALLOW WINDS TO DIMINISH A BIT IN E-C WI MID-MORNING. THAT WILL
PROBABLY STILL HAPPEN SE OF GRB. BUT NEW RUC KEEPS VERY TIGHT
GRADIENT OVER THE BAY OF GREEN BAY...AND OVER THE CITY...AND
CONTINUES TO INCREASE WINDS THROUGH 17Z. RUC SOUNDING ON BUFKIT
SHOWS TEMPERATURE PROFILE DANGEROUSLY CLOSE TO DRY-ADIABATIC INTO
50 KT WINDS AT 2K FT...OVER UNFROZEN BAY WATERS ARND 3-4C. GIVEN
THAT WE/VE GOT LOTS OF EVERGREENS WEIGHTED DOWN WITH WET SNOW
RIGHT NOW...THOSE KIND OF WINDS COMING DOWN TO THE SURFACE COULD
CAUSE EVEN MORE POWER OUTAGES. WILL CONTINUE TO WATCH THIS
CLOSELY.
DISCUSSION ISSUED AT 336 AM CST WED DEC 9 2009...
SHORT TERM...CLASSIC PANHANDLE HOOK-TYPE BLIZZARD CYCLONE NOW IN
NORTHERN ILLINOIS. LOW AT 982 MB AND STILL DEEPENING RAPIDLY. IT/S
AMAZING WATCHING SURFACE PRESSURES AT A HANDFUL OF STATIONS ACROSS
PORTIONS OF SE IA AND W-C IL CONTINUE TO FALL EVEN THOUGH THE LOW
IS PULLING AWAY.
NO CHANGES TO HEADLINES. BLIZZARD CONDITIONS NOW ONGOING IN GREEN
BAY. BAND OF VERY HEAVY SNOW SHIFTG NWD...BUT CONVECTIVE ELEMENTS
FEEDING IN FROM THE SOUTH SHOULD KEEP IT IN ESSENTIALLY THE SAME
PLACE FOR THE NEXT SEVERAL HOURS. GOING SNOWFALL TOTALS IN THE
BALL PARK...WL PROBABLY MAKE ONE LAST SET OF TWEAKS BASED ON
REPORTS RECEIVED UP TO ISSUANCE. MOST PROBLEMATIC AREA IS
LAKESHORE...WHERE WARMING FROM LAKE CONTINUED TO RESULT IN A MIX
WITH RAIN AT TIMES...AND GREATELY REDUCED SNOW TOTALS. BUT WINDS
WL BE BACKING MORE NLY...AND WITH PLENTY OF HEAVY PRECIP STILL TO
GO CAN/T GIVE UP ON THAT AREA YET. SUSPECT I/LL END UP NUDGING
TOTALS DOWN RIGHT AT THE LAKESHORE. BUT THE WESTERN PART OF
MANITOWOC AND KEWAUNEE COUNTIES WL PROBABLY HAVE TOTALS SIMILAR TO
GRB.
STRONGEST WINDS JUST STARTING OVER E-C WI. RUC SHOWED 925 WINDS
NOW AT 45 KTS...AND STILL FROM ABOUT 060 DEG. STRONGEST WINDS IN
GRB SHOULD BE WHEN WINDS COME AROUND THROUGH 040 DEG AND SURGE
DOWN STILL UNFROZEN BAY. WOULD NOT BE SURPRISED IF WE END UP WITH
A FEW 50 MPH GUSTS NEAR THE SHORE OF THE BAY OR NEAR THE LAKE IN
NRN DOOR COUNTY.
MAIN CHG TO THE REST OF THE FCST WAS TO WIND DOWN SNOW A LITTLE
QUICKER THIS AFTN. ALSO THINK WE WERE AND MAYBE STILL ARE A LITTLE
TOO SLOW TO BREAK CLOUDS UP AS SYSTEM DEPARTS. NOT SURE REALLY
COLD AIR WL MAKE IT INTO THE AREA TNGT...SO HELD MINS UP SOME. BUT
MAY NOT GET MUCH IF ANY RECOVERY TOMORROW...AS WLY FLOW BY THAT
TIME SHOULD ALLOW COLD AIR FM THE PLAINS AND SRN CANADA TO SURGE
ACRS THE REGION.
LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY. DRY...COLD
NORTHWEST UPPER FLOW EXPECTED THURSDAY NIGHT THROUGH FRIDAY NIGHT.
WIND CHILL ADVISORY CRITERIA WILL LIKELY BE MET THURSDAY NIGHT AND
EARLY FRIDAY WITH TEMPERATURES AT OR BELOW ZERO AND WINDS OF 10 TO
15 KNOTS. LOW LEVEL WINDS ARE NOT FAVORABLE FOR LAKE EFFECT SNOW
IN VILAS COUNTY DESPITE INSTABILITY. MODELS AGREE ON THE ABOVE.
THEN THERE IS DISAGREEMNT AMONGST THE MODELS WITH REGARD TO A
SHORTWAVE TROUGH LIFTING OUT OF THE SOUTHWESTERN UNITED STATES
SUNDAY AND MONDAY. THE ECMWF IS FASTER AND ALMOST NEGATIVELY
TILTED WITH THIS SYSTEM...GENERATING A SURFACE LOW OVER SOUTHWEST
KANSAS SUNDAY NIGHT THAT MOVES TO SOUTHERN LAKE MICHIGAN BY MONDAY
NIGHT. THAT COULD PRODUCE SIGNIFICANT SNOW. THE GFS IS SLOWER AND
WEAKER WITH THE SYSTEM AND FORMS A SURFACE LOW MUCH FURTHER NORTH
IN NORTHERN NEBRASKA OR SOUTHERN SOUTH DAKOTA. THIS LOOKS TO BE
THE RESULT OF SOME SORT OF PHASING OF THE POLAR AND SUB TROPICAL
JETS. THINK THE JETS ARE TOO FAR APART FOR THAT AND WOULD FAVOR A
SYSTEM FURTHER SOUTH. SO WE MAY NEED TO CONSIDER ADDING SNOW TO
THE FORECAST FOR SUNDAY NIGHT AND MONDAY.
DESPITE THE DIFFERENCES WITH THE SYSTEM MOVING THROUGH
MONDAY...THE MODELS AGREE THAT ARTIC AIR WILL POUR INTO THE
CENTRAL UNITED STATES MONDAY NIGHT AND TUESDAY BEHIND THE SYSTEM.
THE GFS BUFKIT DATA SUGGEST THAT SUB ZERO DAYTIME TEMPERATURES
ARE POSSIBLE TUESDAY WITH VERY COLD WIND CHILLS.
AVIATION...MOST OF THE AREA IS IN IFR OR LIFR CATEGORY...WITH A
FEW LCNS VLIFR. THOSE CONDITIONS SHOULD PERSIST MOST OF THE
MORNING...THEN SLOWLY IMPROVE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING UNTIL MIDNIGHT CST TONIGHT FOR WIZ013-020>022-
030-031-035>040-045-048>050-073-074.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR WIZ005-
010>012-018-019.
&&
$$
