Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KGYX 181033 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 633 AM EDT SAT OCT 18 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TODAY. A STRONG NORTHWEST FLOW WILL SET UP BEHIND THE FRONT TONIGHT THROUGH SUNDAY. HIGH PRESSURE WILL BUILD SOUTH OF NEW ENGLAND SUNDAY NIGHT AND MONDAY. LOW PRESSURE WILL SHIFT SOUTHEAST FROM THE GREAT LAKES TUESDAY AND WILL REDEVELOP OFF THE MID ATLANTIC COAST TUESDAY NIGHT. LOW PRESSURE WILL MEANDER OFF THE NEW ENGLAND COAST WEDNESDAY THROUGH THURSDAY. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
UPDATE...HAVE UPDATED THE GRIDS EARLY THIS MORNING BASED ON CURRENT OBSERVATIONS AND RADAR TRENDS. STRONG COLD FRONT HAS NOW CROSSED THROUGH BINGHAMTON...SYRACUSE AND WATERTOWN. A FEW SHOWERS WILL ENTER THE REGION IN ASSOCIATION WITH THIS FEATURE BY MID MORNING OVER WESTERN NEW HAMPSHIRE. THE SHOWERS WILL BE MOST PERSISTENT IN THE MOUNTAINS AND FOOTHILLS WHERE BEST DYNAMICS WILL COME INTO PLAY. ONLY A CHANCE FOR A SHOWER FURTHER TO THE SOUTH AND EAST. HAVE INCREASED WIND GRIDS FOR SUNDAY. WINDS WILL BE ALIGNED THROUGH A DEEP LAYER AS THE GRADIENT INCREASES. PREV DISC... HAVE BLENDED MESOSCALE MODELS FOR THE PASSAGE OF A COLD FRONT AROUND 18Z OVER WESTERN NEW HAMPSHIRE THROUGH 00Z OVER THE PENOBSCOT VALLEY AREA. WITH THE PASSAGE OF THIS STRONG FRONT...A LINE OF SHOWERS WILL FORM...BRINGING PRECIP TO SEVERAL AREAS...WITH THE HIGHEST CHANCE POPS OVER THE NORTH AND MOUNTAINS. IT WILL CONTINUE TO BE MILD WITH TEMPERATURES WELL INTO THE 60S. THERE WILL BE SOME PATCHY INLAND VALLEY FOG EARLY AS WELL.
-- End Changed Discussion --
&& .SHORT TERM /SUNDAY/... SIGNIFICANT COLD AIR ADVECTION WILL DOMINATE THE REGION. EXPECT UPSLOPE SHOWERS OVER THE NORTHWEST FACING HIGHER TERRAIN. WITH H850 TEMPERATURES AT OR BELOW -4C ON SUNDAY...TEMPERATURES WILL ONLY MAKE IT INTO THE 40S IN THE MOUNTAINS. ACROSS THE COAST...EXPECT ONLY LOWER 50S DESPITE STRONG DOWNSLOPING SIGNATURES DURING THE DAY AND ADIABATIC WARMING. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... WITH THE COLD AIR FIRMLY IN PLACE SUNDAY NIGHT IT IS POSSIBLE THAT FREEZING TEMPERATURES MAY MAKE IT ALL THE WAY TO THE COAST FOR THE FIRST TIME THIS SEASON. STILL CONCERNED THOUGH THAT WINDS WILL STAY UP TOO MUCH FOR GOOD RADIATIONAL COOLING ESPECIALLY IN THE EASTERN PART OF THE AREA. BUT EVEN WITHOUT GOOD RADIATIONAL COOLING CONDITIONS TEMPERATURES MAY FALL INTO THE LOW TO MID 30S AT THE COAST. SINCE THE GROWING SEASON HAS NOT ENDED IN THESE AREAS A FROST ADVISORY OR FREEZE WARNING MAY BE NEEDED. THE REST OF THE AREA WILL LIKELY FALL WELL BELOW FREEZING BUT THE GROWING SEASON HAS ENDED AND FROST/FREEZE PRODUCTS WILL NOT BE ISSUED. CONTINUED COOL CONDITIONS ON MONDAY AS HIGH PRESSURE SLIPS OFF TO THE EAST. HIGHS ONLY MAKE IT INTO THE UPPER 40S TO LOW 50S. MEANWHILE... AN UPPER LEVEL TROUGH DIGS SOUTHWARD THROUGH THE WESTERN GREAT LAKES ON MONDAY AND BEGINS TO CUT ITSELF OFF OVER THE MID ATLANTIC AND NORTHEAST TUESDAY AND WEDNESDAY... MAKING ONLY SLOW PROGRESS EASTWARD INTO THE ATLANTIC THROUGH FRIDAY. THIS IS GOING TO SET THE STAGE FOR A PROLONGED PERIOD OF WET WEATHER FOR NORTHERN NEW ENGLAND FROM TUESDAY THROUGH FRIDAY. MODELS ARE COMING INTO A LITTLE BETTER AGREEMENT ON THIS UPPER LOW AND THE ASSOCIATED SURFACE FEATURES. SURFACE LOW PRESSURE WILL INITIALLY BE WEAK AS IT CROSSES THE CENTRAL APPALACHIANS AND MOVES TOWARD THE MID ATLANTIC COAST TUESDAY. BUT IT WILL DEEPEN A BIT AS IT TRACKS TOWARD CAPE COD BY THURSDAY MORNING. DESPITE GENERALLY BEING A WEAK SURFACE PRESSURE SYSTEM... THE SLOW MOVEMENT WILL ALLOW FOR TRANSPORT OF SIGNIFICANT AMOUNTS OF MOISTURE FROM THE TROPICS STREAMING UP INTO THE SYSTEM... ULTIMATELY DEPOSITING IT AS RAIN OVER MUCH OF NEW ENGLAND. THE ECMWF MODEL IS STRONGER WITH THE SURFACE LOW THAN THE GFS... AND AS A RESULT PULLS IN EVEN MORE TROPICAL MOISTURE AND PRODUCES SIGNIFICANTLY MORE RAIN. WITH THE SLOW MOVEMENT OF THE SYSTEM... THE RAIN WILL BE MORE ON THAN OFF FOR SEVERAL DAYS. SIGNIFICANT 4-DAY RAINFALL TOTALS ARE POSSIBLE AND COULD RESULT IN FLOODING PRIMARILY ALONG STREAMS AND RIVERS. THIS RIVER FLOODING SCENARIO WOULD BE MORE LIKELY IF THE ECMWF VERSION OF EVENTS UNFOLDS WITH A STRONGER SURFACE LOW AND GREATER SURGE OF TROPICAL MOISTURE INTO THE AREA. WITH ALL THE RAIN AND CLOUD COVER EXPECTED... DAYTIME HIGH TEMPERATURES WILL BE A LITTLE BELOW NORMAL (LOW TO MID 5OS) WHILE OVERNIGHT LOWS WILL BE TRENDING TOWARD ABOVE NORMAL (GENERALLY IN THE 40S). && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...AREAS OF IFR/LIFR CEILINGS AND VISIBILITY EARLY THIS MORNING...IMPROVING TO VFR. LONG TERM...VFR EXPECTED THROUGH MONDAY. CONDITIONS BEGIN TO DETERIORATE ON TUESDAY AS RAIN CHANCES BEGIN AND MVFR/IFR CONDITIONS ARE POSSIBLE. CONDITIONS WILL LIKELY REMAIN NEAR THE IFR RANGE THROUGH FRIDAY DURING A PROLONGED PERIOD OF RAIN. && .MARINE... SHORT TERM...SCA FLAGS WILL REMAIN UP ALONG THE OUTER WATERS. LONG TERM...ADVISORY LEVEL WINDS WILL BE LIKELY THROUGH MONDAY MORNING AS COLD NORTHWEST FLOW BEHIND A COLD FRONT REMAINS GUSTY. CONDITIONS IMPROVE MONDAY AND TUESDAY... BUT THERE COULD BE A RETURN TO STRONGER WINDS (THIS TIME OUT OF THE NORTHEAST) FOR WEDNESDAY AND THURSDAY AS LOW PRESSURE DEVELOPS OFFSHORE. NORTHEAST WINDS IN THE 25 TO 35 KT RANGE ARE POSSIBLE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ150-152-154. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.