522  
FXUS61 KGYX 291347  
AFDGYX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAY ME  
947 AM EDT WED MAR 29 2017  
   
SYNOPSIS
 
 
BEHIND A DEPARTING LOW PRESSURE SYSTEM, A NORTHWESTERLY FLOW  
WILL INTRODUCE COOLER AND DRIER AIR INTO THE REGION TODAY. HIGH  
PRESSURE WILL BUILD INTO THE REGION FOR THURSDAY. LOW PRESSURE  
WILL THEN APPROACH THE REGION FOR LATE FRIDAY INTO SATURDAY  
WITH SNOW AND MIXED PRECIPITATION LIKELY FOR THE REGION.  
CANADIAN HIGH PRESSURE WILL THEN BUILD INTO THE REGION ON  
SUNDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
945 AM UPDATE...A FEW MINOR ADJUSTMENTS, MAINLY TO POPS AND  
TEMPERATURES FOR TODAY. MOSTLY DRY WEATHER IS EXPECTED OUTSIDE  
OF NWLY UPSLOPE REGIONS IN THE MOUNTAINS. HOWEVER, FOR THE NEXT  
HOUR, A VERY NARROW CONVERGENCE BAND OF RAIN SHOWERS ACROSS  
FRANKLIN, ANDROSCOGGIN, AND CUMBERLAND COUNTIES SHOULD PERSIST  
FOR A LITTLE BIT, THEN DISSIPATE. OTHERWISE, WE RAISED SNOW  
AMOUNTS A LITTLE BIT FOR FRI NIGHT-SAT, BUT A FULL PERUSAL OF  
THE 12Z DATA IS NEEDED TO ASSESS TRENDS WITH THE UPCOMING  
STORM.  
 
730AM... MINOR UPDATE TO CURRENT CONDITIONS. FOG HAS LIFTED  
ALONG ALL BUT THE IMMEDIATE COAST.  
 
5AM... JUST AN ADJUSTMENT TO THE RAIN AS THE SHOWERS ARE NOW  
ALMOST OFF SHORE. FOG IS BEGINNING TO DISSIPATE ALONG THE  
VERMONT BORDER AS THE LOW MOVES OUT.  
 
AS OF 3AM, VERY DAMP AND FOGGY CONDITIONS ACROSS MAINE AND NEW  
HAMPSHIRE. TEMPERATURES ARE IN THE MID 30S ACROSS THE REGION  
WITH DEWPOINTS SIMILAR. WITH MOST OF THE REGION STILL COVERED IN  
SNOW THIS RELATIVELY WARMER AIR HAS RESULTED IN PATCHES OF DENSE  
FOG. THIS FOG WILL DISSIPATE IN THE EARLY MORNING WITH THE  
MORNING SUN AND DEVELOPING DRIER FLOW.  
 
A LOW CENTER MOVING NORTHEAST THROUGH THE GULF OF MAINE TODAY  
WILL BRING SHOWERS TO COASTAL MAINE AND NEW HAMPSHIRE THROUGH  
MID MORNING. AS THE RAIN DEPARTS NORTHWESTERLY FLOW WILL DEVELOP  
BRINING DRIER CONDITIONS. CLOUDS WILL SLOWLY CLEAR IN THE SOUTH.  
IN THE MOUNTAINS A FEW UPSLOPE SHOWERS WILL DEVELOP.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/
 
 
HIGH PRESSURE WILL BUILD IN FOR TONIGHT AND THURSDAY. HIGH  
TEMPERATURES WILL RETURN TO THE MID 40S SOUTH TO UPPER 30S NORTH  
WITH MOSTLY SUNNY SKIES AND LIGHT WINDS.  
 

 
   
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
 
 
STILL SOME UNCERTAINTY WITH UPCOMING STORM SYSTEM AT THE END OF  
THIS WEEK IN TERMS OF SNOWFALL PROJECTIONS.  
 
CANADIAN HIGH PRESSURE WILL REMAIN ENTRENCHED OVER THE FORECAST  
AREA ON THURSDAY. IT WILL GRADUALLY RETREAT TO THE NORTH AND  
EAST ON FRIDAY AS LOW PRESSURE EXITS THE OHIO VALLEY.  
 
00Z OPERATIONAL MODEL SUITE AND ENSEMBLE MEMBERS ARE IN BETTER  
AGREEMENT TONIGHT BRINGING LOW PRESSURE TO THE NEW JERSEY  
COASTLINE FRIDAY NIGHT WHERE IT WILL UNDERGO ONLY SOME MODEST  
INTENSIFICATION. NEVERTHELESS, PROLONGED PERIOD OF NORTHEAST  
FLOW AND WARM AIR ADVECTION PATTERN ALOFT MAY VERY WELL ALLOW  
FOR STEADY PRECIPITATION FRIDAY INTO SATURDAY. MODEL QPF DOES  
VARY HOWEVER WITH THE EURO BEING THE WETTEST AT THIS TIME.  
 
BOUNDARY LAYER TEMPERATURES MAY BE AN ISSUE OVER SOUTHERN AREAS  
ARE THEY OFTEN ARE IN THE LATE MARCH AND EARLY APRIL TIME  
FRAME. USED PTPYE FROM WET BULB FOR THE INITIAL PORTION OF THE  
FORECAST. AS THE SYSTEM DEPARTS ON ITS EASTERLY TRACK LATE  
SATURDAY, A PLOWABLE SNOWFALL IS POSSIBLE, MAINLY OVER INTERIOR  
LOCATIONS AWAY FROM THE SHORELINE.  
 
CANADIAN HIGH PRESSURE WILL THEN REASSERT ITSELF ON SUNDAY AS  
MORE COLD AIR AND NEAR OR SLIGHTLY BELOW NORMAL TEMPERATURES  
ADVECT INTO THE REGION. THIS SETS THE STAGE FOR ANOTHER POSSIBLE  
REPEAT WITH LOW PRESSURE PASSING BY TO OUR SOUTH DURING THE  
MIDDLE OF NEXT WEEK. TEMPERATURES INITIALLY LOOK A LITTLE WARMER  
FOR THIS SECOND EVENT.  
 

 
   
AVIATION /14Z WEDNESDAY THROUGH SUNDAY/
 
 
SHORT TERM...GENERALLY MVFR THROUGH NEW HAMPSHIRE AND TOWARDS  
THE NORTHWEST OF MAINE. THE LOW BRINGING ALL THIS MOISTURE WILL  
MOVE OFF SHORE TODAY AND EXPECT CONDITIONS TO IMPROVE TO MVFR  
REGION WIDE BY MID MORNING. CONDITIONS WILL CONTINUE TO IMPROVE  
INTO THURSDAY WITH JUST A CHANCE FOR MVFR CEILINGS IN SNOW  
SHOWERS NEAR THE INTERNATIONAL BORDER.  
 
LONG TERM...IFR CONDITIONS DEVELOPING FRIDAY WITH AREA OF LIFR  
OVER SOUTHERN AREAS POSSIBLE. THESE CONDITIONS WILL CONTINUE  
INTO SATURDAY AS LOW PRESSURE PASSES BY TO OUR SOUTH. CONDITIONS  
IMPROVE TO VFR ON SUNDAY.  
 

 
   
MARINE
 
 
SHORT TERM... GENERALLY CALM WATERS CURRENTLY. EXPECT WINDS TO  
PICK UP THIS AFTERNOON UNDER NORTHWESTERLY FLOW AS THE CURRENT  
LOW DEPARTS. A SMALL CRAFT ADVISORY HAS BEEN ISSUED BEGINNING  
LATE THIS AFTERNOON AND EXTENDING THROUGH THE OVERNIGHT HOURS.  
THERE ISN'T REALLY AN UPPER LEVEL JET TO MIX DOWN ANY STRONG  
WINDS BUT COLD ADVECTION SHOULD BE ENOUGH TO REACH SCA EVEN IN  
THE BAYS.  
 
LONG TERM...SCA CONDITIONS MAY OCCUR FRIDAY NIGHT INTO SATURDAY  
AS LOW PRESSURE PASSES BY TO OUR SOUTH. SCA CONDITIONS POSSIBLE  
ONCE AGAIN MIDWEEK, NEXT WEEK AS YET ANOTHER AREA OF LOW  
PRESSURE PASSES BY TO OUR SOUTH.  
 

 
   
TIDES/COASTAL FLOODING
 
 
A VERY HIGH ASTRONOMICAL TIDE WILL OCCUR EARLY FRIDAY MORNING  
WITH 11.1' EXPECTED IN PORTLAND AT AROUND 06Z. ONSHORE WINDS AND  
SEAS WILL JUST BE BEGINNING TO DEVELOP AT THIS TIME. NORTHEAST  
FLOW WILL BE MORE PRONOUNCED DURING THE SATURDAY AFTERNOON HIGH  
TIDE WHICH IS LOWER AT 10.3'. EXPECT ABOUT A 0.5 TO 1.0 STORM  
SURGE AT THAT TIME WHICH WOULD BRING THE STORM TIDE TO AROUND  
11.0 FEET OR SO. WITH WAVES RUNNING 5 FEET OR SO AT THE TIME,  
SPLASH-OVER NOMOGRAMS SUGGEST TO ONLY EXPECT LITTLE IN THE WAY  
OF ISSUES ALONG THE COASTLINE.  
 

 
   
GYX WATCHES/WARNINGS/ADVISORIES
 
 
ME...NONE.  
NH...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 PM EDT  
THURSDAY FOR ANZ150>154.  
 

 
 

 
 
NEAR TERM...EKSTER  
 
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