Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 251415 AAA AFDGYX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAY ME 1015 AM EDT WED MAR 25 2015 .SYNOPSIS... HIGH PRESSURE WILL SHIFT OFFSHORE TODAY WHILE A WARM FRONT APPROACH FROM THE WEST. THIS WARM FRONT WILL MOVE ACROSS OUR AREA TONIGHT. LOW PRESSURE WILL THEN APPROACH FROM THE WEST THURSDAY AND CROSS OUR REGION THURSDAY NIGHT. HIGH PRESSURE WILL THEN GRADUALLY BUILD INTO THE NORTHEAST THROUGH SUNDAY. LOW PRESSURE ACROSS SOUTHERN CANADA WILL THEN SWING ACROSS NORTHERN MAINE BY TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1015 AM UPDATE...UPDATED TO ADJUST FOR CURRENT TEMPERATURE TRENDS. OTHERWISE FORECAST IS IN GOOD SHAPE. && PREVIOUSLY... HIGH PRESSURE CENTERED DIRECTLY OVERHEAD THIS MORNING WILL SHIFT OFFSHORE THIS AFTERNOON. TEMPERATURES SHOULD BE RELATIVELY WARM ONCE AGAIN WITH PLENTY OF SUNSHINE THROUGH AT LEAST MID TO LATE AFTERNOON. MOS GUIDANCE HAS BEEN MUCH TOO LOW ON HIGH TEMPERATURES THE LAST FEW DAYS AND WILL PROBABLY BE AT LEAST A COUPLE OF DEGREES TOO LOW TODAY EVEN THOUGH WE/LL LOSE THE DOWNSLOPING COMPONENT TO THE WIND. A SHORT WAVE TROUGH AND WARM FRONT APPROACHES THE REGION FROM THE WEST LATE TODAY...AND THIS MAY ALLOW A BAND OF LIGHT RAIN...POSSIBLY MIXED WITH SLEET...TO REACH THE CT VALLEY BETWEEN 21Z AND 00Z THIS AFTERNOON/EVENING. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... WARM FRONT PUSHES ACROSS THE REGION TONIGHT. THIS WARM FRONT WILL BE ACCOMPANIED BY A QUICK-MOVING AND NARROW BAND OF LIGHT PRECIPITATION...MAINLY THIS EVENING. THE DOMINANT PRECIPITATION TYPE SHOULD BE IN THE FORM OF LIGHT RAIN. HOWEVER...A FEW SNOWFLAKES OR A LITTLE BIT OF SLEET MAY MIX IN FOR A LITTLE WHILE DUE TO EVAPORATIONAL COOLING IN THE COLUMN. A LITTLE BIT OF FREEZING RAIN MAY OCCUR IN THE FAR INTERIOR AS WELL. HOWEVER...WILL ALLOW DAY SHIFT TO TAKE A LOOK AT THIS POSSIBILITY BEFORE ISSUING ANY SORT OF ADVISORY. ALL IN ALL...PRECIPITATION WILL BE VERY LIGHT...LESS THAN A TENTH OF AN INCH OF LIQUID IS EXPECTED. AFTER MIDNIGHT...WE DO NOT EXPECT MUCH TO BE HAPPENING...JUST SOME LOW CLOUDS...FOG...AND PERHAPS SOME DRIZZLE. ON THURSDAY...WE MAY SEE SOME BREAKS OF SUN IN THE MORNING AS WE WILL BE IN THE WARM SECTOR. THIS SHOULD ALLOW TEMPERATURES TO WARM UP APPRECIABLY...PROBABLY INTO THE LOWER 50S AT LOWER ELEVATIONS...ESPECIALLY ACROSS SOUTHERN NH. LOW PRESSURE APPROACHES FROM THE WEST IN THE AFTERNOON AND THIS WILL SPREAD A GOOD STEADY RAIN ACROSS THE AREA. THE LOW PRESSURE SYSTEM IS EXPECTED TO TRACK ACROSS SOUTHERN NH LATE THU AND THU NIGHT. THEREFORE...WE EXPECT COOLING TEMPERATURES TO THE NORTH OF THE LOW TRACK. THE COLUMN SHOULD COOL ENOUGH ACROSS OUR ZONES ADJACENT TO THE CANADIAN BORDER FOR SOME ACCUMULATING SNOW...MAINLY THU NIGHT. WOULD NOT BE SURPRISED TO SEE PLACES LIKE PITTSBURG NH EASTWARD TO COBURN GORE AND EUSTIS ME TO PICK UP 3 TO 6 INCHES OF SNOW. FURTHER SOUTH...MAINLY RAIN IS EXPECTED...BUT A CHANGE TO SNOW BEFORE THE PRECIP SHIELD EXITS LATE THU NIGHT IS POSSIBLE. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... THE MODELS ARE IN GENERAL AGREEMENT ON THE LONG WAVE PATTERN THROUGH EARLY NEXT WEEK...WHILE TIMING AND STRENGTH OF INDIVIDUAL SHORTWAVES DIFFER MARKEDLY AFTER SUNDAY WITH BELOW NORMAL CONFIDENCE IN SENSIBLE WEATHER BY EARLY NEXT WEEK. TEMPERATURES WILL CONTINUE TO RUN BELOW NORMAL FOR THE PERIOD...AS THE MEAN JET POSITION WILL BE TO OUR SOUTH. WE BEGIN THE PERIOD WITH A DEEP UPPER TROUGH TO OUR WEST AND SURFACE LOW PRESSURE EXITING TO OUR EAST. THE UPPER TROUGH WILL SLIDE EAST...AND PROVIDE A FEW CLOUDS AND SCATTERED RAIN AND SNOW SHOWERS TO THE AREA INTO SATURDAY...BEFORE IT TO EXITS THE COAST. RIDGING SURFACE AND ALOFT PROVIDES A QUIET...SUNNY...BUT SEASONABLY COOL DAY FOR THE SECOND HALF OF THE WEEKEND. THE NEXT SHORTWAVE DIVES QUICKLY SOUTHEAST WITH ASSOCIATED SURFACE LOW AND TRAILING COLD FRONT TO CROSS THE REGION ON MONDAY. THE ECMWF IS PROGRESSIVE WITH THIS SYSTEM...WHILE THE GFS HAS SECONDARY DEVELOPMENT NEAR THE NEW ENGLAND COAST MONDAY NIGHT WITH CLOUDS AND PRECIPITATION LINGERING INTO TUESDAY. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...VFR CONDITIONS ARE EXPECTED TODAY. MVFR TO IFR CONDITIONS ARE EXPECTED TO DEVELOP TONIGHT IN LOW CLOUDS AND SOME FOG AS A WARM FRONT MOVES THROUGH. A BRIEF RETURN TO VFR CONDITIONS WILL BE POSSIBLE THURSDAY MORNING BEFORE IFR CONDITIONS IN RAIN DEVELOP THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. LONG TERM... FRI - SAT...SCT MVFR PSBL IN RAIN AND SNOW SHOWERS. && .MARINE... SHORT TERM...SCA CONDITIONS WILL LIKELY DEVELOP LATE THIS AFTERNOON OR EARLY THIS EVENING AS HIGH PRESSURE MOVES OFFSHORE AND A WARM FRONT MOVES TOWARD OUR AREA. WINDS AND SEAS WILL COME DOWN THURSDAY MORNING BUT SEAS MAY RAMP UP AGAIN TO SCA LEVELS THU NIGHT. LONG TERM... FRI - SAT...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE. && .HYDROLOGY... A RAIN EVENT IS EXPECTED THURSDAY AFTERNOON AND NIGHT FOR MOST OF THE REGION WITH 0.5 TO 1 INCH OF QPF EXPECTED WITH LOCALLY HIGHER AMOUNTS POSSIBLE. SOME OF THIS WILL LIKELY BE IN THE FORM OF SNOW NEAR THE CANADIAN BORDER. THE COMBINATION OF WARM TEMPERATURES THURSDAY AND THURSDAY NIGHT AND THIS EXPECTED RAINFALL MAY CAUSE FOR SOME ICE MOVEMENT ON RIVERS AND MAY CAUSE SOME LOCALIZED MINOR FLOODING. HOWEVER...THE CURRENT SNOWPACK IS NOT QUITE RIPE AND SHOULD HANDLE A GOOD PORTION OF THE EXPECTED QPF. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR ANZ153. SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO NOON EDT THURSDAY FOR ANZ150>152-154. && $$ UPDATE...HANES

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