Area Forecast Discussion
Issued by NWS Portland, ME

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816 FXUS61 KGYX 060842 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 342 AM EST SAT FEB 6 2016 .SYNOPSIS...
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A RIDGE OF HIGH PRESSURE WILL BUILD TO OUR SOUTH TODAY. LOW PRESSURE TRACKING ACROSS QUEBEC WILL SPREAD A FEW CLOUDS INTO NORTHERN AND MOUNTAIN SECTIONS LATER TODAY ALONG WITH SCATTERED SNOW SHOWERS. A TRAILING COLD FRONT WILL DROP GRADUALLY SOUTH ACROSS THE REGION TONIGHT AND SUNDAY ACCOMPANIED BY A FEW SNOW SHOWERS AND MOUNTAIN SNOW SQUALLS. LOW PRESSURE IN THE ATLANTIC WILL TRACK TO THE NORTHEAST WELL TO THE EAST OF CAPE COD ON MONDAY. ANOTHER LOW WILL TAKE A SIMILAR TRACK ON TUESDAY AND LINGER OVER THE AREA THROUGH THURSDAY.
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&& .NEAR TERM /THROUGH TODAY/...
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AT 07Z...A 1031 MILLIBAR HIGH WAS CENTERED OVER VIRGINIA. A 1015 MILLIBAR LOW WAS CENTERED OVER THE UPPER GREAT LAKES. GOES INFRARED IMAGERY SHOWED CLEAR SKIES ACROSS THE FORECAST AREA AT MOMENT. HOWEVER...THERE WAS A BAND OF MID CLOUDS UPSTREAM ACROSS THE EASTERN GREAT LAKES IN ADVANCE OF THE GREAT LAKES DISTURBANCE. THEY`LL SLIDE EAST INTO THE FORECAST AREA WITH THE MOST WIDESPREAD CLOUD COVER...AND ANY SNOW SHOWER ACTIVITY...CONFINED TO NORTHERN AND MOUNTAIN SECTIONS. THE CIRCULATION BETWEEN THE GREAT LAKES DISTURBANCE AND THE BUILDING HIGH TO OUR SOUTH WILL ALLOW TEMPERATURES TO CLIMB INTO THE 30S.
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&& .SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/...
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THE NORTHERN STREAM IMPULSE AND ASSOCIATED SURFACE LOW TRACK TO OUR NORTH TONIGHT AND EARLY SUNDAY. THIS WILL HELP DRIVE A TRAILING COLD FRONT SOUTHWARD ACROSS THE FORECAST AREA. ACROSS NORTHERN AND MOUNTAIN SECTIONS WE`LL SEE THE MOST WIDESPREAD CLOUDS AND SNOW SHOWER ACTIVITY WITH THE FRONT. THERE MAY EVEN BE A FEW SQUALLS ACROSS THE MOUNTAINS WITH ITS PASSAGE AS WELL AS UPSLOPE CLOUDS AND SNOW SHOWERS BEHIND IT. ON SUNDAY...WE STRUGGLE TO GET ABOVE 30F IN THE MOUNTAINS BEHIND THE COLD FRONT...WHILE WE`LL WARM INTO THE 40S ELSEWHERE AS WE AWAIT THE COLDER AIRS ARRIVAL FOLLOWING THE COLD FRONTAL PASSAGE.
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&& .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
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QUITE A BIT UNCERTAINTY REMAINS IN THE EVOLUTION AND TRACKS OF LOW PRESSURE SYSTEMS EARLY NEXT WEEK. THE MAIN FORECAST CHALLENGES REMAINS THE EVENTUAL SENSIBLE WEATHER MONDAY THROUGH WEDNESDAY. THE MAIN PLAYERS ON THE TABLE REMAIN A SOUTHERN STREAM SHORT WAVE TROUGH MOVING WELL OFF THE MID ATLANTIC COAST ON MONDAY WITH THE OTHER BEING THE LARGE UPPER LOW DROPPING SOUTHEASTWARD ACROSS THE GREAT LAKES AND OHIO VALLEY WITH A FEW SMALL SHORT WAVES EMBEDDED WITHIN. A LONG LOOK AT DETERMINISTIC AND ENSEMBLE DATA OVERNIGHT REVEALS A CONSENSUS THAT FAVORS THE SOUTHERN STREAM LOW BEING TOO FAR OUT TO SEA ON MONDAY AND MONDAY NIGHT FOR A SIGNIFICANT IMPACT ON OUR AREA. ALL OF THE 50 ECMWF ENSEMBLE MEMBERS ARE TIGHTLY CLUSTERED AROUND A SFC LOW TRACK WELL SOUTHEAST OF THE 40/70 BENCHMARK. THIS SUPPORTS THE 00Z DETERMINISTIC RUNS OF THE ECMWF AND GFS. THEREFORE A BIG IMPACT FROM THIS LOW IS NOT EXPECTED. HOWEVER...OUR REGION OF NORTHERN NEW ENGLAND DOES GET INTO A COL REGION MONDAY AFTERNOON AND NIGHT. THIS WILL PRESENT A BROAD REGION OF FRONTOGENESIS AND WEAK FORCING FOR ASCENT WHICH WILL LIKELY RESULT IN A FAIRLY BROAD AREA OF LIGHT SNOW DEVELOPING. LIGHT SNOW FIRST DEVELOPS ALONG THE COAST AND ACROSS SOUTHERN NH BY LATE MON AFTERNOON...THEN SPREADING INLAND MONDAY NIGHT. THIS MAY RESULT IN 1 TO 3 INCHES OF SNOW THROUGH THAT TIME FRAME. THE TUESDAY AND WEDNESDAY TIME FRAME PAINTS A MORE UNCERTAIN PICTURE AS MODEL AND ENSEMBLE SPREAD INCREASES. A LARGE AND DEEP UPPER TROUGH ENCOMPASSING MUCH OF THE REAL ESTATE EAST OF THE MISSISSIPPI RIVER BY TUESDAY MORNING AND IT/S ASSOCIATED SHORT WAVE TROUGHS WILL MOVE TOWARD THE EAST COAST. MOST DETERMINISTIC MODELS AND ENSEMBLE MEMBERS AGREE THAT SFC LOW PRESSURE WILL DEVELOP AS A RESULT...BUT WHERE AND HOW STRONG IS THE PROBLEM. MUCH OF THE 00Z ECMWF ENSEMBLE MEMBERS ARE SCATTERED ALL OVER THE PLACE BY TUESDAY NIGHT WITH THE BEST CLUSTERING OF LOW CENTERS EAST OF IT/S 00Z DETERMINISTIC RUN. HOWEVER...SEVERAL OF THE 50 ENSEMBLE MEMBERS DO DEVELOP STRONG CYCLOGENESIS CLOSE ENOUGH TO THE COAST FOR AT LEAST A MODERATE-IMPACT SNOWSTORM SOMEWHAT LIKE THE 00Z DETERMINISTIC RUN. THIS SENTIMENT IS SHARED BY A SMALL NUMBER OF GFS ENSEMBLE MEMBERS. THEREFORE AS OF THIS WRITING...WILL HANDLE THE SITUATION WITH HIGH CHANCE POPS TUESDAY NIGHT...MAINLY ALONG THE COASTAL PLAIN BASED ON THE REMAINING WIDE RANGE OF POSSIBILITIES. IN A NUTSHELL...WE ARE NOT OUT OF THE WOODS YET AS FAR AS A POSSIBLE IMPACTFUL SNOWSTORM GOES...CENTERED AROUND LATE TUESDAY AND TUESDAY NIGHT. HOWEVER...THE MOST LIKELY SCENARIO REMAINS SOMETHING OF LOWER IMPACT. WILL CONTINUE TO MONITOR TRENDS. THEREAFTER...THE 00Z GFS AND ECMWF TRY TO DROP THE POLAR VORTEX ON TOP OF US NEXT WEEKEND...AT LEAST FOR A SHORT TIME. IF THAT VERIFIED WE WOULD PROBABLY SEE THE COLDEST WEATHER OF THE SEASON. BUT WE/LL SEE.
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&& .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
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SHORT TERM...VFR CONDITIONS. SCT MVFR AFT 21Z IN ANY MTN -SHSN. AREAS OF MVFR AFT 06Z IN MTN -SHSN WITH LCL IFR PSBL IN MTN SNOW SQUALLS. LONG TERM...MVFR CONDITIONS POSSIBLY DEVELOP ON MONDAY IN LIGHT SNOW...WITH COULD CONTINUE ON AND OFF THROUGH TUESDAY. A COASTAL STORM WILL BE POSSIBLE LATER TUE AND TUE NIGHT WITH ASSOCIATED LOWER CONDITIONS IN SNOW...BUT CONFIDENCE IS QUITE LOW AT THIS TIME.
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&& .MARINE...
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SHORT TERM...WINDS AND SEAS SHOULD BUILD LATER TODAY IN STRENGTHENING SOUTHERLY FLOW AHEAD OF THE COLD FRONT WITH SMALL CRAFT CONDITIONS EXPECTED OUTSIDE THE BAYS...WITH CONDITIONS LINGERING TONIGHT. LONG TERM...SMALL CRAFT CONDITIONS ARE EXPECTED MUCH OF THE LONG TERM PERIOD...MAINLY SUNDAY NIGHT THROUGH WEDNESDAY. GALES WILL BE POSSIBLE DURING THIS TIME AS WELL...MAINLY LATER SUNDAY NIGHT THROUGH MONDAY. LOW PRESSURE WILL LIKELY AFFECT THE WATERS ONCE AGAIN AROUND TUESDAY NIGHT...BUT STRENGTH AND TRACK IS UNCERTAIN AT THIS TIME.
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&& .GYX WATCHES/WARNINGS/ADVISORIES...
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ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ150-152-154.
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&& $$ NEAR/SHORT TERM...SCHWIBS LONG TERM...EKSTER

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