Area Forecast Discussion
Issued by NWS Portland, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KGYX 231522 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 1022 AM EST TUE DEC 23 2014 .SYNOPSIS... AN ONSHORE FLOW WILL CONTINUE TODAY. A SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT LAKES WEDNESDAY INTO THURSDAY. THIS COULD BRING WINDY CONDITIONS AND THE POTENTIAL FOR HEAVY RAIN AROUND CHRISTMAS EVE INTO EARLY CHRISTMAS MORNING. ANOTHER LOW PRESSURE SYSTEM WILL APPROACH THE REGION LATE IN THE WEEKEND AND EARLY MONDAY POTENTIALLY BRINGING SOME WINTRY WEATHER. CANADIAN HIGH PRESSURE TO FOLLOW. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE: ONLY MINOR TWEAKS AS THE R/S LINE CONTINUES TO MOVE SLOWLY NORTH AND WEST FURTHER INLAND. 8 AM UPDATE: QUICK UPDATE TO NUDGE THE R/S LINE CLOSER TO THE COAST FOR THE NEXT HOUR OR TWO DUE TO A HEAVY BAND OF PCPN ALLOWING COLD AIR MIXING DOWN TO THE SFC. ALSO, WILL MENTION SOME ACCUMULATIONS OF AROUND AN INCH OR SO IN PARTS OF INLAND CUMBERLAND AND ANDROSCOGGIN COUNTIES ON NORTH FOR THIS MORNING BEFORE THE CHANGEOVER TO RAIN. THE WAA WILL OVERTAKE THE AREA BY LATER THIS MORNING AND THESE AREAS WILL CHANGE OVER TO RAIN AS TEMPS MOVE ABOVE FREEZING. NO OTHER CHANGES ATTM. 605 AM...MINOR ESTF UPDATE TO 1ST PERIOD GRIDS TO INGEST THE CURRENT MESONET. PREV DISC... UPDATE... HAVE UPDATED THE GRIDS TO DROP THE WINTER WEATHER ADVISORY FOR SOUTHERN NH. NOW FOCUSING ON ONGOING SNOW IN THE NORTH WHICH WILL LIKELY CHANGE TO FREEZING RAIN TONIGHT. A COASTAL FLOOD ADVISORY HAS BEEN ISSUED FOR THE LATE MORNING HIGH TIDE TODAY. NAM12 STILL SHOWING HIGH RAINFALL TOTALS FOR THE MOUNTAINS WITH SIGNATURES OF A STRONG UPSLOPE COMPONENT. PREV DISC... PATCHY FREEZING RAIN MAY CONTINUE TO BE AN ISSUE FOR A FEW MORE HOURS OVER SOUTHWEST NH AS THE PRECIP ENTERS THE REGION PER LATEST RADAR IMAGERY. TEMPS CONTINUE TO HOVER AROUND THE 32 DEGREE MARK IN THIS REGION. THIS ADVISORY WILL MOST LIKELY BE CANCELED OVER THE NEXT FEW HOURS. OTHERWISE...BOUNDARY LAYER TEMPS WILL DETERMINE LOCAL CONDITIONS TODAY AS THE PRECIP MOVES FROM SW TO NE. IN MOST AREAS THE PRECIP TYPES OF RA/SN WILL DOMINATE. EXPECT 1 TO 2 INCHES OF SNOW AWAY FROM THE COAST OVER SEVERAL INTERIOR LOCATIONS AS THE ATMOSPHERE WILL BE JUST COLD ENOUGH TO SUPPORT FROZEN PRECIP. USED THE BTV TOP DOWN TOOL FOR PTYPE TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... THE PRECIP WILL CONTINUE TONIGHT AS NORTHERNMOST AREAS SLIP BELOW FREEZING ONCE AGAIN. THEREFORE...HAVE ISSUED WINTER WEATHER ADVISORIES FOR THE MOUNTAINS. A LIGHT ACCUM OF ICE CAN BE EXPECTED. AS IS TYPICAL FOR NORTHERN NEW ENGLAND...THE SURFACE LOW ALONG THE NEW ENGLAND COASTLINE WILL CONTINUE TO DRAW COOLER AIR INTO THE REGION FROM THE NORTH...IN A COLD AIR DAMMING SITUATION. THIS WILL BE AIDED BY A COASTAL FRONT WHICH HAS FORMED OVER THE REGION EARLY THIS MORNING. RAISED ALL MODEL GUIDANCE FOR WINDS THROUGH WEDNESDAY AS PERSISTENT SURFACE LOW REMAINS TO OUR SOUTH AND WEST. WARM AIR ADVECTION SETS THE STAGE FOR POSSIBLY A RECORD BREAKING WARM CHRISTMAS DAY FOR PORTLAND THIS YEAR. THE OLD RECORD HIGH ON CHRISTMAS WAS 53 DEGREES SET BACK IN 1994. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... THE MODELS ARE IN GENERAL AGREEMENT ON THE LONG WAVE PATTERN THROUGH EARLY NEXT WEEK. WE BEGIN THE PERIOD WITH A POTENT TROUGH TO OUR WEST. THE TROUGH LIFTS NORTHEAST AND DRIVES A COLD FRONT ACROSS THE REGION ON THURSDAY. WARM AIR SURGING NORTH AHEAD OF THIS FRONT WILL PRODUCE RECORD...OR NEAR RECORD HIGHS ON CHRISTMAS DAY...ESPECIALLY IF WE BREAKOUT AND SEE A PERIOD OF POST-FRONTAL SUNSHINE. THE WARM TEMPERATURES AND SNOW MELT...COMBINED WITH A BASIN AVERAGE OF TWO INCHES OF RAINFALL...COULD PUSH SOME RIVERS AND STREAMS TO BANKFULL BY CHRISTMAS DAY. A BROAD FLAT RIDGE FOLLOWS FOR FRIDAY AND SATURDAY WITH A CONTINUATION OF MILD TEMPERATURES AS HIGH PRESSURE BUILDS BY TO OUR SOUTH. A FAST MOVING IMPULSE WILL DRIVE A COLD FRONT ACROSS THE AREA EARLY SUNDAY ACCOMPANIED BY A FEW RAIN AND SNOW SHOWERS. HIGH PRESSURE WILL BUILD BY TO OUR NORTH SUNDAY NIGHT AND MONDAY. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... SHORT TERM...VSBYS DECREASING WITH IFR CONDITIONS AND LOCALLY LIFR CONDITIONS TODAY THROUGH WEDNESDAY. LONG TERM... THU...MVFR IN SHOWERS. SFC WND GUSTING UP TO 35 KT. && .MARINE... SHORT TERM...HAVE INCREASED WIND AND WAVE FIELDS FROM CURRENT OPERATIONAL GUIDANCE FOR TODAY THROUGH WEDNESDAY FOR THE SHORT TERM PORTION OF THE FORECAST. MODELS CONTINUE TO BE OVERLY WEAK HANDLING WIND AND WAVE CONDITIONS FOR THIS EVENT. SCAS REMAIN IN EFFECT FOR GUSTY ESE WINDS. LONG TERM... THU...GALE FORCE WINDS ARE LIKELY. FRI - SAT...SMALL CRAFT WINDS AND SEAS ARE LIKELY. && .HYDROLOGY... HAVE NOT ISSUED A FLOOD WATCH AT THIS TIME. HOWEVER...THE NAM12 DOES A GOOD JOB PICKING UP ON THE UPSLOP CONDITIONS...BRINGING NEARLY 4 INCHES OF RAIN TO THE N CONWAY AREA. THE UPPER SACO WILL NEED TO BE MONITORED CLOSELY AS WITH OTHER RIVERS/STREAMS. && .TIDES/COASTAL FLOODING... HAVE ISSUED A COASTAL FLOOD ADVISORY FOR THE LATE MORNING TIDE. PERSISTENT EASTERLY WINDS WILL BRING THE PORTLAND AND HAMPTON TIDES CLOSE TO FLOOD STAGE TODAY AS WE APPROACH OUR HIGHEST ASTRONOMICAL TIDES OF THE MONTH. MINOR FLOODING POSSIBLE IN PORTLAND HARBOR...GRANITE POINT ROAD IN BIDDEFORD AND THE BACKBAY AREA OF HAMPTON NH. ASTRONOMICAL TIDE ARE LOWER TONIGHT. THEREFORE...NO ADVISORIES HAVE BEEN ISSUED FOR THIS TIME PERIOD ALONG THE COAST AT THIS TIME. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO 8 AM EST WEDNESDAY FOR MEZ007>009. COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MEZ023-024. NH...FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO 8 AM EST WEDNESDAY FOR NHZ001-002. COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NHZ014. MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR ANZ150>154. SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR ANZ150>154. && $$

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