794
FXUS63 KGRB 210347 AAB
AFDGRB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREEN BAY WI
947 PM CST FRI NOV 20 2009
UPDATE
GOING TO HOLD OFF ON DENSE FOG ADVISORY AT THIS POINT.
WL CERTAINLY WILL SEE PATCHES OF DENSE FOG...BUT JUST NOT SURE
IT/S GOING TO BE WIDESPREAD ENOUGH TO WARRANT AN ADVISORY. WILL
ISSUE SPS DETAILING THE IMPACT ON HUNTERS AND OTHER MOVING AROUND
EARLY SATURDAY MORNING. CONCERNED ABOUT THE POSSIBILITY ROADS
COULD BECOME SLIPPERY AS A THICK LAYER OF FROST DEVELOPS ON THE
ROADWAY BY MORNING. WILL ALSO MENTION THAT IN THE SPS.
ALREADY UPDATED ZONES AND GRIDS A COUPLE HOURS AGO TO HAVE
MENTION OF PATCHY DENSE FOG. WL TWEAK MINS DOWN A BIT...AND HAVE
UPDATE OUT SHORTLY.
SKOWRONSKI
PREV DISCUSSION...ISSUED AT 923 PM CST FRI NOV 20 2009
UPDATE...VSBYS DROPPING ACRS THE N WHERE SKIES HAVE CLEARED.
OBVIOUSLY GOING TO HAVE PATCHY DENSE FOG...QUESTION IS WHETHER OR
NOT IT BECOMES DENSE ENOUGH TO WARRANT AND ADVISORY. REALIZING
THERE WILL BE A LOT OF MOVEMENT EARLY TOMORROW AS HUNTERS HEAD OUT
FOR THE START OF THE DEER SEASON...AM A LITTLE MORE WILLING THAN
NORMAL TO GO WITH AN ADVISORY FOR MARGINAL CONDITIONS. WL CONTINUE
TO MONITOR OBS FOR A BIT LONGER...BUT INTEND TO HAVE DECISION
BEFORE 1000 PM.
SKOWRONSKI
DISCUSSION ISSUED AT 310 PM CST FRI NOV 20 2009...
SHORT TERM....LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW
A SHORTWAVE PROGRESSING TO THE EAST ACROSS THE WESTERN GREAT LAKES
THIS AFTERNOON WITH BROAD CYCLONIC FLOW AT THE SURFACE. ALTHOUGH
CLOUDY SKIES PREVAIL AHEAD OF THE WAVE IN A FAIRLY SOUPY LOW LEVEL
AIRMASS...FORCING AND MOISTURE DEPTH HAVE NOT BEEN SUFFICIENT ENOUGH
FOR ANY PRECIP. SKIES HAVE CLEARED ACROSS ALL OF MINNESOTA AND FAR
NORTHWEST WISCONSIN BEHIND THE SHORTWAVE THIS AFTERNOON AS RIDGING
BUILDS INTO THE REGION. FORECAST CONCERNS OVER THE NEXT 24 HOURS
INCLUDE CLOUD TRENDS AND FOG POTENTIAL TONIGHT.
TONIGHT...THE SHORTWAVE TROUGH WILL CONTINUE TO SLOWLY PASS ACROSS
THE AREA DURING THE EVENING BEFORE EXITING AFTER MIDNIGHT. WILL SEE
DECREASING CLOUD COVER AS THIS OCCURS...WHILE BROAD LOW LEVEL
CYCLONIC FLOW GETS REPLACED BY AN INCOMING WEAK RIDGE AXIS. A DRIER
LOW LEVEL AIRMASS WILL FILTER INTO THE STATE FROM THE WEST AND
WILL EAT AWAY AT THE JUICY AIR IN PLACE CURRENTLY. WITH CLEARING
SKIES...LIGHT WINDS...AND A REASONABLY MOIST BOUNDARY LAYER...EXPECT
TO SEE SOME RADIATIONAL FOG TOMORROW MORNING. BEST CHANCES WILL
APPEAR TO BE ACROSS THE HIGHER TERRAIN OF N-C WISCONSIN...WHERE
CLEARING WILL ARRIVE FIRST. LOOKING UPSTREAM LAST NIGHT...THERE WAS
SOME PATCHY DENSE FOG ACROSS NORTHERN MINNESOTA...ESPECIALLY WITHIN
LOW LYING VALLEYS. CROSS-OVER TEMPS UPSTREAM APPEAR TO BE AROUND
30F OR IN THE LOWER 30S...SO THOSE AREAS WHERE MIN TEMPS FALL BELOW
THIS THRESHOLD WILL BE MORE SUSCEPTIBLE TO FOG. AS A RESULT...WILL
BEEF UP FOG WORDING ACROSS N-C WISCONSIN TO AREAS...BUT KEEP PATCHY
ELSEWHERE WHERE TEMPS WILL ONLY FALL INTO THE THE LOW TO MID 30S.
TOMORROW...A QUIET DAY TOMORROW ONCE THE FOG BURNS OFF BY
MID-MORNING DUE TO THE PRESENCE OF RIDGING THROUGH THE COLUMN. A
LACK OF CLOUD COVER UPSTREAM SUGGESTS A MOSTLY SUNNY DAY. 925MB
TEMPS AROUND 6C WILL YIELD HIGHS IN THE LOW TO MID 50S.
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
MEDIUM RANGE MODEL SOLUTIONS ONCE AGAIN STARTED DOING THEIR OWN
THING BY EARLY NEXT WEEK. THIS ONCE AGAIN LED TO HPC GUIDANCE
BEING FOLLOWED MORE CLOSELY THAN ANY OF THE 12Z MODEL RUNS. RAIN
CHANCES WERE CONFINED TO THE WESTERN PART OF THE FORECAST AREA
SUNDAY NIGHT...AHEAD OF AN APPROACHING COLD FRONT. PRECIPITATION
CHANCES CONTINUED INTO WEDNESDAY AS THE HPC MANUAL SURFACE PROG
BROUGHT A LOW THROUGH WISCONSIN. COLDER AIR IN THE WAKE OF THE
SYSTEM MADE PRECIPITATION TYPE AN ISSUE FOR TUESDAY NIGHT AND
WEDNESDAY SO BOTH RAIN AND SNOW WERE MENTIONED FOR THOSE PERIODS.
LAKE EFFECT APPEARED TO BE A POSSIBILITY ACROSS THE EXTREME NORTH
AND NORTHEAST STARTING THURSDAY...AS DELTA TS...LAKE SURFACE TO
850MB...INCREASE. OTHERWISE ONLY WENT WITH SOME SLIGHT CHANCE POPS
ACROSS THE AREA. MADE A GOOD FAITH EFFORT TO BLEND WELL WITH
SURROUNDING FORECAST GRIDS.
DID NOT MAKE MAJOR CHANGES TO HIGH OR LOW TEMPERATURES.
AVIATION...MVFR VSBYS WILL IMPROVE TO VFR THIS AFTERNOON AND EARLY
THIS EVENING AS SKIES WILL SEE A GRADUAL CLEARING TREND. WILL SEE
RADIATIONAL FOG DEVELOP TONIGHT WITH THE BIGGEST IMPACT EXPECTED AT
RHI TOMORROW MORNING WHERE LIFR VSBYS (OR POSSIBLY LOWER) ARE
POSSIBLE. A LITTLE MORE UNCERTAINTY EXISTS AT AUW/CWA/GRB AS ITS
TOUGH TO GAUGE HOW MUCH DRY AIR IN THE LOW LEVELS WILL ARRIVE
TONITE. THINK THAT AT LEAST IFR VSBYS ARE POSSIBLE AT AUW/CWA AND
MVFR AT GRB. WILL LET THE EVENING CREW MONITOR TRENDS AND ADJUST.
ONCE ANY FOG BURNS OFF BY MID-MORNING TOMORROW...VFR CONDITIONS WILL
PREVAIL THROUGH THE REST OF THE DAY.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page