208 FXUS61 KCAR 042300 AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 600 PM EST SUN MAR 4 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE NORTHEAST OF THE CANADIAN MARITIMES LATE TONIGHT...BRINGING A SLOW MOVING ARCTIC COLD FRONT ACROSS THE REGION THROUGH MONDAY MORNING. AFTER THE PASSAGE OF AN UPPER TROUGH MONDAY...ARCTIC HIGH PRESSURE WILL SLOWLY BUILD TOWARD THE REGION MONDAY NIGHT AND TUESDAY. && .NEAR TERM /THROUGH MONDAY/... NO MAJOR CHGS TO FCST GRIDS IN THE IMMEDIATE NEAR TERM ATTM. ONE OF THE BIGGER CHALLENGES OVRNGT WILL BE LOCATING THE ARCTIC FRONT AS IT MOVES W TO E ACROSS THE REGION FROM ERN QB...WITH THE BROAD FRONT SOMEWHAT DIFFICULT TO DISTINGUISH FROM THE TYPICAL NGT TM SFC BASED INVSN AT OUR OBS SITES. THIS FRONT WILL ONLY BE ABLE TO MAKE SLOW PROGRESS ACROSS THE REGION WITH THE FLOW ALF AHEAD OF THE S/WV TROF FROM SRN QB NEARLY PARALLEL TO THE N TO S ORIENTATION OF THE SFC FRONT. WE DID INCLUDE LATEST OBSVD SFC TEMPS AND MERGED THEM TO FCST HRLY TEMPS AT 06-07Z. ORGNL DISC: LOW PRESSURE WILL CONTINUE TO TRACK NORTHEAST FROM THE MID ATLANTIC REGION...PASSING TO THE SOUTH OF NOVA SCOTIA LATER TONIGHT THROUGH EARLY MONDAY. A TROF EXTENDING WEST ACROSS THE FORECAST AREA FROM THIS LOW WILL INTERACT WITH AN UPPER LEVEL DISTURBANCE APPROACHING FROM THE WEST BRINGING SCATTERED SNOW SHOWERS LATER TONIGHT INTO MONDAY. ANY SNOW ACCUMULATION SHOULD BE AROUND AN INCH OR SO THROUGH MONDAY. THE UPPER DISTURBANCE WILL MOVE EAST MONDAY AFTERNOON WITH ANY SCATTERED SNOW SHOWERS DIMINISHING. COLDER AIR WILL FILTER IN BEHIND THE LOW LATER TONIGHT AND MONDAY. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOW TO MID TEENS NORTH AND UPPER TEENS TO AROUND 20 NORTH. HIGHS ON MONDAY WILL BE SEVERAL DEGREES COLDER WITH HIGHS ACROSS THE NORTH RANGING FROM THE UPPER TEENS TO LOWER 20S NORTH AND UPPER 20S TO LOWER 30S DOWNEAST. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... GENERALLY DRY AND MILDER THRU THE SHORT TERM PERIOD... TROF OF LOW PRES JUST TO THE E OF THE FA MON EVE. WILL KEEP SOME CLOUDS ACROSS THE N AND E MON NGT ALONG WITH SOME LINGERING -SHSN ACROSS THE FAVORED NRN AREAS. EXPECT THE CLOUDS TO BEGIN DCRSG FROM W-E OVERNIGHT W/ THE -SHSN DIMINISHING DURING THE EVE HRS. OTHERWISE...HIGH PRES RIDGED N-S FROM WRN QUEBEC TO THE GULF STATES MON EVE WILL GRADUALLY BUILD EWRD INTO OUR FA THRU TUE THEN MOVE E OF THE FA ON WED. INITIALLY ON THE COLD SIDE OF THINGS THRU TUE NGT WILL RESULT IN TEMPS A LITTLE BLO SEASONAL NORMS THRU TUE NGT. BY WED...A RETURN SWRLY FLOW OF MUCH MILDER AIR WILL BEGIN TO OVERSPREAD THE AREA AFTER THE RIDGE CRESTS THE AREA LATE TUE NGT AND SHIFTS E OF THE AREA ON WED. IN ADDITION...SHOULD SEE A WARM FRONT LIFT NE ACROSS THE AREA W/ SOME CLOUDS AND A SLGT CHC OF RAIN/SNOW SHOWERS FAR NW BY WED AFTN... EXPECT HIGH TEMPS TO RANGE FROM AROUND 40 N TO THE MID TO UPPER 40S S ON WED... && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE GFS AND ECMWF CONTINUE TO AGREE AT THE START OF THE LONG TERM ON THE POSITION OF THE MAIN SYSTEMS. A HIGH PRESSURE RIDGE ALONG THE ERN SEABOARD...A LOW PRESSURE SYSTEM WITH MULTIPLE LOWS EXTENDING FROM HUDSON BAY TO TEXAS. BY THURSDAY THE RIDGE WILL SHIFT FURTHER INTO THE N ATLANTIC AS THE LOW OVER HUDSON BAY MOVES INTO NRN QUEBEC. THE FRONTAL SYSTEM WILL EXTEND SW ACROSS THE CENTRAL GREAT LAKES. BY THURSDAY THE LOW MOVES INTO THE WRN CANADIAN MARITIMES WITH THE COLD FRONT EXTENDING SW THROUGH MAINE TO A 2NDRY LOW OVER AR. BY FRIDAY MORNING THE COLD FRONT WILL BE THROUGH THE AREA INTO THE SRN GULF OF MAINE WATERS. A WEAK RIDGE OF HIGHER PRESSURE WILL BUILD ACROSS MAINE. THE 2NDRY LOW OVER AR DEEPENS AND MOVES TO SRN IL (GFS) THE ECMWF MAINTAINS THE LOW OVER AR WITH A NEW LOW OVER THE NRN GREAT LAKES. BY FRIDAY EVENING THE GFS AND ECMWF NO LONGER HAVE A SIMILAR SOLUTION. THE GFS MOVES A NEW LOW SE ACROSS HUDSON BAY TOWARDS SE QUEBEC. THE ECMWF DEEPENS THE LOW OVER THE NRN GREAT LAKES AND MOVES IT TO COASTAL MAINE. BOTH MODELS MAINTAIN THEIR 2NDRY LOWS IN THEIR RESPECTIVE LOCATIONS. BY SATURDAY MORNING THE MODELS TOOK A DIFFERENT TRACK TO GET THERE...HOWEVER THE SOLUTION FOR THE LOCAL AREA WILL BE SIMILAR. THE GFS MOVES ITS LOW INTO THE GULF OF ST LAWRENCE...BEGINS TO BUILD HIGHER PRESSURE INTO WRN ME. THE ECMWF MOVES ITS LOW TO PRINCE EDWARD ISLAND...BEGINS TO BUILD HIGHER PRESSURE INTO THE LOCAL AREA. THE HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH SUNDAY NIGHT. BY EARLY MONDAY MORNING ANOTHER LOW WILL MOVE SE OUT OF THE HUDSON BAY REGION...THE HIGHER PRESSURE WILL RIDGE OFF THE COAST BY THE END OF THE PERIOD THE LOW WILL MOVE INTO THE WRN CANADIAN MARITIMES...HIGHER PRESSURE WILL BRIEFLY BUILD BACK INTO THE AREA. LOADED GMOS...ADJUSTED THE SKY AND POP GRIDS TO BETTER SUPPORT ONE ANOTHER. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. PLUS 15 PERCENT FOR WIND GUSTS OVER LAND...20 PERCENT OVER WATER. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... NEAR TERM: VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. MVFR CONDITIONS ARE POSSIBLE LATER TONIGHT KBGR/KBHB IN SCT SNOW SHOWERS WITH THESE CONDITIONS EVENTUALLY REACHING THE NORTHERN TAF SITES LATER TONIGHT THROUGH EARLY MONDAY. CONDITIONS SHOULD IMPROVE TO VFR ALL TAF SITES LATER MONDAY. SHORT TERM: A PERIOD OF MVFR IS PSBL LATE THU THRU THU NGT...SPCLY ACROSS THE NRN TAF SITES AS A STRONG COLD FRONT CROSSES THE REGION. OTHERWISE...MAINLY VFR CONDS EXPECTED THRU THE PERIOD... && .MARINE... NEAR TERM: SMALL CRAFT CONDITIONS WILL CONTINUE TONIGHT AND MONDAY...MAINLY FOR SEAS. SHORT TERM: SCA CONDS MAY LINGER INTO MON EVE AND LATER SHIFTS MAY NEED TO EXTEND THE CURRENT SCA ACCORDINGLY. SCA CONDS MAY REDEVELOP ON WED IN INCRSG SW FLOW AS A RIDGE OF HIGH PRES MOVES OFF TO THE E AND A STRONG COLD FRONT APPROACHES FROM THE NW... && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR ANZ050-051. && $$ NEAR TERM...VJN SHORT TERM...KHW LONG TERM...NORTON AVIATION...VJN MARINE...VJN/KHW