Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 121745 AAD AFDGYX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAY ME 1245 PM EST FRI FEB 12 2016 .SYNOPSIS... LOW PRESSURE WILL APPROACH FROM THE WEST TODAY AND WILL DISSIPATE INTO A TROUGH OF LOW PRESSURE OVER CENTRAL MAINE BY SATURDAY MORNING. TROUGH OF LOW PRESSURE WILL SHIFT SOUTHEAST SATURDAY THROUGH SATURDAY NIGHT LEAVING A STRONG NORTHWEST FLOW IN IT`S WAKE. HIGH PRESSURE WILL BUILD IN FROM THE WEST SUNDAY AND WILL CREST OVER THE REGION SUNDAY NIGHT. HIGH PRESSURE WILL SHIFT OFFSHORE EARLY MONDAY AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. WARM FRONT WILL LIFT INTO SOUTHERN NEW ENGLAND MONDAY NIGHT AND WILL LIFT NORTH OF THE REGION ON TUESDAY AS LOW PRESSURE MOVES UP THE EAST COAST. LOW PRESSURE WILL MOVE NORTH THROUGH WESTERN NEW NEW ENGLAND TUESDAY NIGHT AND INTO EASTERN QUEBEC BY WEDNESDAY MORNING. HIGH PRESSURE WILL BUILD IN FROM THE WEST WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12PM UPDATE...WITH VERY GOOD AGREEMENT COMING IN WITH THE 12Z MODEL SUITE...HAVE HOISTED WINTER STORM WATCHES ALONG THE GYX SIDE OF PENOBSCOT BAY /KNOX-WALDO COUNTIES/ FOR 6-10 INCHES OF POTENTIAL SNOW ACCUMULATION. HAVE ALSO ADDED COASTAL ZONES INTO WIND CHILL HEADLINES /ADVISORIES/ AS CONFIDENCE IS QUITE HIGH IN REACHING ADVISORY CRITERIA IN THESE ZONES SATURDAY NIGHT. 11AM UPDATE...GOING FORECAST IN GOOD SHAPE LATE THIS MORNING WITH BRIGHT SUN HELPING TEMPERATURES TO SLOWLY REBOUND THROUGH THE SINGLE DIGITS AND INTO THE LOW TEENS. UPDATED FOR NEAR TERM TRENDS...WITH GRADUALLY INCREASING HIGH CLOUDS EXPECTED THROUGH THIS AFTERNOON AS TEMPERATURES RISE THROUGH THE TEENS. WILL BE CONSIDERING WINTER WEATHER HEADLINES FOR SNOW ALONG THE MIDCOAST THIS AFTERNOON AS 12Z NAM/GFS CONSISTENTLY BULLSEYE THE PENOBSCOT BAY REGION BY LATE TONIGHT AND THROUGH SATURDAY. MORE ON THIS...THIS AFTERNOON. 9AM UPDATE...HAVE CANCELLED WIND CHILL ADVISORY AS TEMPERATURES REBOUND THIS MORNING. ADDITIONALLY...WILL TRANSITION ONGOING WIND CHILL WATCHES TO WARNINGS FOR SATURDAY NIGHT. PRIMARY CHANGES TO THE NEAR TERM GRIDS INCLUDE CLEARING OUT ALL CLOUD COVER FOR THE MORNING HOURS AS CRYSTAL CLEAR SKIES DOMINATE THE AREA THIS MORNING. NO OTHER CHANGES TO THE FORECAST ATTM. PREVIOUS BELOW... SHALLOW RIDGE OF HIGH PRESSURE OVER THE REGION EARLY THIS MORNING WILL SHIFT OFFSHORE TODAY AS LOW PRESSURE APPROACHES FROM THE WEST. AFTER A MOSTLY SUNNY MORNING...EXPECT INCREASING CLOUDS THIS AFTERNOON AS LOW PRESSURE SHIFTS INTO SOUTHWEST QUEBEC. MAY SEE A STRAY SNOW SHOWER...MAINLY IN THE MOUNTAINS BUT EXPECT MOST OF THE FORECAST AREA TO SEE A DRY DAY. HIGH TEMPERATURES WILL TOP OUT IN THE LOWER MID TEENS NORTH AND UPPER TEENS TO LOWER 20S SOUTH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... LOW PRESSURE WILL GRADUALLY OPEN INTO AN INVERTED TROUGH AS IT SHIFTS INTO NORTHERN MAINE OVERNIGHT. TROUGH AXIS WILL BE CENTERED ON THE MID COAST AREA WHERE INCREASING SURFACE CONVERGENCE AND ONSHORE FLOW WILL RESULT IN A LOCALIZED AREA OF SNOW OVERNIGHT AND INTO SATURDAY. CARIBOU STICKING WITH WATCHES AT THIS POINT AND SO WILL LET THE DAY SHIFT GET ANOTHER LOOK AT THE MODELS BEFORE DECIDING ON HEADLINES. EXPECT ACCUMULATIONS OF 3 TO 5 INCHES OVERNIGHT WITH SOME ADDITIONAL ACCUMULATIONS LIKELY ON SATURDAY. REMAINDER OF THE FORECAST AREA WILL SEE A MOSTLY CLOUDY NIGHT WITH A CHANCE OF SNOW SHOWERS. LOWS WILL DIP INTO THE SINGLE NUMBERS NORTH AND LOWER TO MID TEENS SOUTH. TROUGH AXIS WILL GRADUALLY SHIFT SOUTH AND EAST ON SATURDAY WITH A STRONG NORTHWEST FLOW SETTING UP IN ITS WAKE ACROSS THE REGION. EXPECT SEVERAL MORE INCHES OF ACCUMULATION ON SATURDAY IN FAR EASTERN COASTAL ZONES BEFORE SNOW TAPERS OFF LATER IN THE DAY. LIGHT FLUFFY SNOW WILL RESULT IN CONSIDERABLE BLOWING AND DRIFTING AS NORTHWEST GRADIENT TIGHTENS IN THE AFTERNOON. MAY SEE SOME SUNNY BREAKS IN SOUTHERN NEW HAMPSHIRE BUT MOST OF WESTERN MAINE AND NEW HAMPSHIRE WILL SEE MOSTLY CLOUDY SKIES WITH A CHANCE OF SNOW SHOWERS. TEMPERATURES WILL SHOW LITTLE CHANGE DURING THE DAY WITH HIGHS OF 5 TO 15 NORTH AND IN THE MID TEENS TO LOWER 20S SOUTH. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE EXTENDED FORECAST PERIOD LOOKS EXTREMELY COLD WITH THE POLAR VORTEX DIPPING INTO THE NORTHEAST THROUGH SUNDAY. AN ARCTIC AIRMASS WILL POUR INTO THE REGION WITH SPRAWLING DENSE HIGH PRESSURE AT THE SURFACE DOMINATING THE EAST COAST SUNDAY AND MOST OF MONDAY. LOWS SUNDAY MORNING WILL BE IN THE NEGATIVE NUMBERS AREAWIDE WITH THE NORTH COUNTRY IN THE LOWER NEGATIVE 20S. LOOKING AT NAEFS AND GEFS ANOMALY INDICATORS FOR THIS EVENT SHOWS JUST HOW COLD THIS AIRMASS IS. THE NAEFS CLIMATOLOGICAL PERCENTILES FOR GEOPOTENTIAL HEIGHTS AND TEMPERATURES INDICATE MINIMUMS FOR MOST HEIGHTS AROUND SUNDAY AT 00Z AND 06Z. THIS MEANS THAT WE ARE FORECASTING AN EVENT HAS NOT OCCURRED WITHIN THE NAEFS 1979-2009 CLIMATOLOGY FOR THIS TIME OF YEAR. ALSO THE NAEFS R INTERVAL IS OUTSIDE CLIMATOLOGY AT 500MB OVER OUR REGION AND JUST TO OUR SOUTH. NOT SURPRISINGLY PWATS ARE ALSO FORECASTED TO BE IN THE BOTTOM ONE PERCENTILE FOR THE NAEFS CLIMATE RECORD. SNOW SHOWERS WILL COME TO AN END QUICKLY SUNDAY AS THE HIGH PRESSURE NUDGES IN FROM THE WEST. NW WINDS WILL BE GUSTY BEHIND THE DEPARTING ARCTIC FRONT AND WILL BE MORE THAN ENOUGH TO REQUIRE A WIND CHILL WARNING FOR THE ENTIRE AREA AND FOR MUCH OF THE DAY SUNDAY. CURRENTLY HAVE LEFT THE WIND CHILL WATCH UP AS IS AND AS WE GET CLOSER TO THE EVENT WE WILL BE ABLE TO ADJUST TIMING A LITTLE BETTER. THEREFORE WILL LEAVE THIS FOR A LATER SHIFT TO ISSUE EVEN THOUGH CONFIDENCE IS HIGH IN ITS NECESSITY. SOME OF THE COLDEST WIND CHILLS APPROACH-40 F ACROSS THE MOUNTAINS. TO THE SOUTH IT WONT BE MUCH BETTER WITH -20 TO -30 F WILL BE MORE COMMON. SUNDAY TEMPERATURES WARM UP ONLY SLIGHTLY INTO THE SINGLE NEGATIVE DIGITS NORTH TO AROUND +5 TO +10 SOUTH. SUNDAY NIGHT WILL BE ANOTHER TERRIBLY COLD NIGHT AND A WIND CHILL ADVISORY MAY BE NEEDED FOR THE NORTHERN TIER OF COUNTIES ABUTTING CANADA. THE SILVER LINING DURING THIS TIME IS THAT WE ARE NOT EXPECTING ANY PRECIPITATION. A COUPLE OF SHORT WAVES ROUNDING THE BASE OF THE UPPER LEVEL TROUGH WILL MOVE TOWARDS NEW ENGLAND AT THE BEGINNING OF NEXT WEEK AND TRY AND PHASE WITH A NORTHERN STREAM IMPULSE. WHETHER THIS HAPPENS REMAINS TO BE SEEN BUT IT DOES APPEAR WE WILL HAVE SEVERAL PERIODS OF PRECIPITATION. AT THE SURFACE... A WARM FRONT LIFTS NORTH INTO THE REGION. PRECIPITATION TYPE IS EXPECTED TO BE A MIX OF SNOW AND RAIN. THERE IS ALSO THE POSSIBILITY OF A WINTRY MIX IN THE TUESDAY NIGHT/EARLY WEDNESDAY TIME FRAME AS WARMER AIR OVERRIDES THE COLDER AIR ALREADY IN PLACE AT THE SURFACE. WENT WITH A NON-DIURNAL TEMPERATURE CURVE FOR THIS TIME PERIOD. ON WEDNESDAY IT APPEARS WE STAY IN THE WARM SECTOR AND WE MAY SEE A WARMER DAY ABOVE FREEZING. HOWEVER COLDER AIR FILTERS IN BY THURSDAY WITH THE COLDEST AIR DAMMING ALONG THE HIGHER TERRAIN. THE NEXT SYSTEM LOOKS TO AFFECT US NEXT FRIDAY NIGHT. THIS LOOKED LIKE ANOTHER IDEAL TIME TO USE A NON-DIURNAL CURVE AS A WARM FRONT ARRIVES OVERNIGHT. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...VFR UNDER MOSTLY CLEAR CONDITIONS ATTM. EXPECT DETERIORATING CONDITIONS THROUGH THE COMING TAF PERIOD WITH SNOW DEVELOPING OVERNIGHT AT RKD AND LIKELY AUG WITH IFR/LIFR RESTRICTIONS. FOR A PERIOD SATURDAY...INCH PER HOUR SNOWFALL RATES ARE POSSIBLE...MOST LIKELY AT RKD. FURTHER WEST...ARCTIC FRONT WILL BRING A ROUND OF SNOW SHOWERS...MOST LIKELY TO BRING RESTRICTIONS TO LEB/HIE...BUT BRIEF RESTRICTIONS ARE POSSIBLE SOUTH AND EAST OF THIS AS WELL. CONDITIONS IMPROVE SATURDAY NIGHT WITH VFR CONDITIONS RETURNING FOR SUNDAY. AFTER LIGHT WINDS OVERNIGHT...STRONG NORTHWEST WINDS /15G25KTS/ WILL DEVELOP BY LATE MORNING SATURDAY AND CONTINUE THROUGH SATURDAY NIGHT. LONG TERM... MVFR/IFR CONDITIONS LIKELY LATE MONDAY THROUGH TUESDAY IN SNOW. && .MARINE... SHORT TERM...CONTINUING SCA`S FOR THE BAYS THROUGH 8 AM AND OUTER WATERS THROUGH NOON. FREEZING SPRAY ADVISORY FOR THE OUTER WATERS UNTIL 10 AM. LONG TERM...SMALL CRAFT ADVISORY/BORDERLINE GALES WILL BE NEEDED DURING THE DAY SUNDAY AS A COLD FRONT CROSSES THE WATERS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR MEZ007>009. WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR MEZ012>014-018>022. WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR MEZ023>028. WINTER STORM WATCH FROM MIDNIGHT EST TONIGHT THROUGH SATURDAY EVENING FOR MEZ022-027-028. NH...WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR NHZ001>003. WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR NHZ004>013-015. WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST SUNDAY FOR NHZ014. MARINE...NONE. && $$ SYNOPSIS...HANES/SINSABAUGH NEAR TERM...ARNOTT/SINSABAUGH SHORT TERM...SINSABAUGH LONG TERM...HANES AVIATION...ARNOTT/HANES MARINE...HANES/SINSABAUGH

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