337  
FXUS61 KGYX 170756  
AFDGYX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAY ME  
356 AM EDT THU AUG 17 2017  
   
SYNOPSIS
 
 
HIGH PRESSURE SETTLES INTO NEW ENGLAND TODAY WITH DRY  
WEATHER AND SEASONABLE TEMPERATURES. ON FRIDAY NIGHT...A WARM  
FRONT ASSOCIATED WITH LOW PRESSURE OVER THE GREAT LAKES WILL  
BRING AN AREA OF RAINFALL TO THE NORTHEAST. THE BEST CHANCES FOR  
A SIGNIFICANT RAINFALL LOOK TO BE FARTHER SOUTH. SATURDAY SHOULD  
BRING A BREAK IN PRECIPITATION UNTIL THE COLD FRONT SWINGS  
THROUGH THE REGION. HIGH PRESSURE WILL BUILD BACK INTO THE  
REGION SUNDAY INTO EARLY NEXT WEEK WITH WARMING TEMPERATURES.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
HIGH PRESSURE WILL MOVE OVER THE REGION TODAY. NORTHWESTERLY  
FLOW WILL CONTINUE THIS MORNING AS THE STRONG UPPER LOW TO OUR  
NORTHEAST PROVIDES A PRESSURE GRADIENT THROUGH THE REGION. THIS  
WILL PREVENT ANY SEABREEZE FROM FORMING ALONG THE COAST.  
ADDITIONALLY A FEW GUSTS TO 20MPH ARE AGAIN POSSIBLE.  
TEMPERATURES WILL REMAIN SEASONABLE WITH HIGHS NEAR 80 SOUTH.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/
 
 
TONIGHT LOOK FOR THE HIGH PRESSURE TO BEGIN TO SHIFT EASTWARDS  
AS THE NEXT SYSTEM MOVES OUT OF THE GREAT LAKES. SKIES SHOULD  
REMAIN MOSTLY CLEAR OVERNIGHT THROUGH THE EASTERN PORTION OF THE  
AREA WITH CLOUDS APPROACHING IN THE WEST. INCREASING HUMIDITY  
AS A WARM FRONT LIFTS NORTH WILL KEEP LOW TEMPERATURES MILDER.  
 
FRIDAY MORNING RAIN WILL MOVE IN AS LOW PRESSURE PUSHES  
EASTWARD. THIS RAIN WILL SPREAD FROM WEST TO EAST ACROSS THE  
AREA DURING THE DAY ON FRIDAY. WITH SOUTHERLY FLOW COMING UP OUT  
OF THE TROPICS AND HIGH PRECIPITABLE WATER VALUES, HEAVY RAIN IS  
POSSIBLE WITHIN THE CONVECTIVE SHOWERS  
 

 
   
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
 
 
LOW PRESSURE LIFTING INTO CANADA WILL CONTINUE TO PUSH A WARM  
FRONT TOWARDS NRN NEW ENGLAND FRI NIGHT. MODEL GUIDANCE SUGGESTS  
THIS FRONT WILL HAVE TROUBLE LIFTING THRU THE FORECAST AREA...SO  
WILL TEND TOWARDS MORE OF AN OCCLUSION WITH TIME. THE BEST LLJ  
FORCING AND RAINFALL POTENTIAL LOOKS TO BE FRI NIGHT...WHERE SRN  
ZONES NEAR THE WARM FRONT COULD SEE A WELCOMED PRECIP EVENT. THE  
NAM FORCING IS A LITTLE MORE INTENSE AND SHARPER...LEADING TO A  
SHORTER DURATION RAINFALL. THE GFS FORECAST SOUNDINGS ARE LONGER  
DURATION 25 KT SSW LLJ THAT BRING OVER A HALF INCH TO COASTAL  
ZONES. THE GFS FORECAST RESEMBLES THE LATEST ECMWF AS WELL...SO  
I WILL CONTINUE THE HEAVIEST PRECIP NEAR THE COAST OVERNIGHT.  
 
AFTER THE OCCLUSION IT WILL BE WARMER SAT AS THE LOW LEVEL  
STABLE AIR IS CLEANED OUT. THE INITIALLY CLEAR DRY SLOT WILL  
GIVE WAY TO AFTERNOON CLOUDS AND SCATTERED SHOWERS OR STORMS  
AHEAD OF THE S/WV TROF AXIS. THE TIMING OF THE TROF APPEARS TO  
BE FAVORING SAT NIGHT...SO NOT ALL THAT FAVORABLE FOR A FOCUSED  
LINE OF CONVECTION. SO FOR NOW I WILL KEEP CHANCE TO SLIGHT  
CHANCE POP IN THE FORECAST FOR SAT. I CANNOT RULE OUT RAIN...BUT  
IT ALSO DOES NOT LOOK LIKE A WIDESPREAD RAIN.  
 
AFTER THE TROF PASSAGE A FLAT RIDGE LOOKS TO BUILD INTO THE  
AREA...THOUGH DEEP SW FLOW WILL BE FEEDING INTO IT. THIS SHOULD  
ALLOW SOME WARMER TEMPS TO WORK BACK INTO THE REGION WITH TIME  
HEADING INTO MIDWEEK. THE NEXT TROF WILL CROSS THE AREA AROUND  
THE WED TIME FRAME.  
 

 
   
AVIATION /07Z THURSDAY THROUGH MONDAY/
 
 
SHORT TERM...VFR WILL CONTINUE ACROSS THE AREA THROUGH LATE  
TONIGHT WITH JUST A CHANCE FOR MORNING VALLEY FOG IN THE  
CONNECTICUT RIVER VALLEY. INCREASING CLOUDS AHEAD OF THE  
APPROACHING SYSTEM WILL EVENTUALLY RESULT IN CEILINGS DECREASING  
AND MVFR CONDITIONS MOVING IN FROM WEST TO EAST DURING FRIDAY  
AFTERNOON. FRIDAY NIGHT IFR IN RAIN AND FOG IS POSSIBLE.  
 
LONG TERM...AREAS OF IFR CONDITIONS POSSIBLE FRI NIGHT INTO SAT  
AS WARM FRONT/OCCLUSION LIFTS INTO THE FORECAST AREA. INTO SAT  
MORNING LLJ FORCING WILL BRING A ROUND OF STEADIER PRECIP TO  
COASTAL ZONES...AND THIS IS PROBABLY THE BEST WINDOW FOR IFR OR  
LOWER CONDITIONS. UNTIL THE COLD FRONT SWEEPS THRU THE REGION  
LATE SAT...SHRA AND/OR AN ISOLATED TSRA ARE POSSIBLE THOUGH  
GENERALLY VFR CONDITIONS WILL PREVAIL. VFR CONDITIONS CONTINUE  
INTO MON.  
 

 
   
MARINE
 
 
SHORT TERM...LONG PERIOD SWELL FROM HURRICANE GERT IS STARTING  
TO ARRIVE IN MIDCOAST MAINE. SWELL OF 7-8FT WITH PERIOD AROUND  
12-14 SECONDS WILL PROVIDE A POWERFUL PULL AND MAY RESULT IN  
INCREASED RIP CURRENT RISK. A HIGH SURF ADVISORY REMAINS IN  
EFFECT THROUGH TONIGHT FOR THE MIDCOAST AND A SMALL CRAFT FOR  
HAZARDOUS SEAS FOR THE ADJACENT OCEAN WATERS. IN THE BAYS  
SHELTERING WILL PREVENT ANY LARGE SWELL WHILE THE SOUTHERN MAINE  
AND NEW HAMPSHIRE COAST ARE TOO EAST FACING TO BE AFFECTED BY  
THE MORE SOUTHERLY SWELL. AFTER THE SWELL DECREASES TONIGHT  
EXPECT A PERIOD OF CALM CONDITIONS ON THE WATERS BEFORE SEAS AND  
WINDS BEGIN TO BUILD AS THE NEXT LOW MOVES THROUGH FRIDAY NIGHT.  
 
LONG TERM...WINDS AND SEAS BUILD IN RESPONSE TO A LLJ LIFTING  
ACROSS THE WATERS WITH THE WARM FRONT. GIVEN THE WAA OVER THE  
RELATIVELY COOLER WATER...WIND GUSTS LOOK TO BE MARGINALLY  
CLOSE TO SCA THRESHOLDS. MORE LIKELY SEAS BUILD TO 5 FT ON THE  
OUTER WATERS FOR A TIME SAT. THE NEXT CHANCE FOR SCA CONDITIONS  
WILL BE CLOSER TO MIDWEEK...AHEAD OF THE NEXT COLD FRONT.  
 

 
   
GYX WATCHES/WARNINGS/ADVISORIES
 
 
ME...HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MEZ025>027.  
NH...NONE.  
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT THIS  
EVENING FOR ANZ150-152.  
 

 
 

 
 
NEAR TERM...CURTIS  
SHORT TERM...CURTIS  
LONG TERM...LEGRO  
AVIATION...CURTIS/LEGRO  
MARINE...CURTIS/LEGRO  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab ME Page
The Nexlab NH Page Main Text Page