RSS FeedsIssued by NWS Green Bay, WI
000 FXUS63 KGRB 202110 AFDGRB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 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. && $$ MPC/MG
