994  
FXUS61 KGYX 261358  
AFDGYX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAY ME  
958 AM EDT WED JUL 26 2017  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL BECOME CENTERED OVER THE AREA TODAY AND MOVE  
OFFSHORE TONIGHT. A COLD FRONT MOVES ACROSS THE AREA ON  
THURSDAY BRINGING SCATTERED SHOWERS AND THUNDERSTORMS. HIGH  
PRESSURE WILL ATTEMPT TO BUILD INTO THE REGION FRIDAY AND  
INTO THE WEEKEND AS LOW PRESSURE MOVES SOUTH OF THE AREA.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
UPDATE...HAVE UPDATED THE FORECAST BASED ON LATEST CONDITIONS.  
LAST OF THE FOG ABOUT TO DISSIPATE OVER THE CONNECTICUT RIVER  
VALLEY BETWEEN 14Z AND 15Z. THIS WILL LEAVE THE REGION WITH  
MAINLY SUNNY SKIES, LIGHT WINDS AND SEASONABLE TEMPERATURES.  
 
THURSDAY APPEARS TO BE MORE ACTIVE WITH SCATTERED SHOWERS AND  
STORMS. A FEW OF THE THUNDERSTORMS MAY CONTAIN DAMAGING WINDS  
AND HAIL. THE MARGINAL RISK HAS BEEN EXPANDED TO INCLUDE OUR  
ENTIRE FORECAST AREA.  
 
PREVIOUS DISCUSSION...WIDESPREAD FOG IN THE RIVER VALLEYS...DENSE  
AT TIMES...WILL LIFT AND DISSIPATE QUICKLY AS DAYTIME HEATING  
GETS UNDERWAY. HIGH PRESSURE WILL BE IN CONTROL...ALLOWING FOR  
SUNNY SKIES AND LIGHT WINDS. HIGH TEMPS SHOULD BE ABLE TO CLIMB  
INTO THE 80S FOR MOST...EXCEPT COOLER IN THE MTNS...AND NEAR THE  
COAST WHERE WEAK PRESSURE GRADIENT WILL ALLOW FOR SEA BREEZES  
TO DEVELOP.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/
 
 
AN APPROACHING S/WV TROF AND ATTENDANT COLD FRONT WILL APPROACH  
THE REGION TONIGHT. AN INITIAL AREA OF SHOWERS AND DECAYING  
STORMS WILL LEAD THE MAIN S/WV TROF. THESE ARE FORECAST TO MOVE  
INTO THE AREA LATE TONIGHT AND EARLY THU. I EXPECT THESE WILL  
MAINLY STAY IN THE MTNS...AND BE ON THE LIGHT SIDE.  
 
THEN THE FOCUS IS ON HOW MUCH CLEARING OCCURS IN THE WAKE OF  
MORNING SHOWERS. LAPSE RATES WILL BE MARGINAL...BUT DEW POINTS  
WILL BE INCREASING ON RETURN FLOW BEHIND HIGH PRESSURE.  
POCKETS OF HEATING SHOULD ALLOW FOR SUFFICIENT CAPE FOR  
THUNDERSTORMS DEVELOPMENT ALONG THE COLD FRONT ITSELF. WITH A H3  
JET STREAK CROSSING THE REGION...SHEAR WILL BE MORE THAN  
ADEQUATE FOR ORGANIZED UPDRAFTS...ESPECIALLY THE SRN PART OF THE  
FORECAST AREA. SO GIVEN THAT WE CAN GET BREAKS IN THE  
CLOUDS...STORMS SHOULD FORM AND SOME OF THESE WILL LIKELY  
ORGANIZE INTO STRONGER CLUSTERS. SREF CALIBRATED SEVERE STORM  
PROBABILITIES HAVE INCREASED OVER THE LAST SEVERAL RUNS...AND  
EXTENDED HRRRX SHOWS A FAIR AMOUNT OF CONVECTIVE DEVELOPMENT BY  
THU AFTERNOON. CONSIDERING THESE RECENT TRENDS...AND SPC  
MARGINAL RISK FOR SEVERE STORMS...I HAVE INCLUDED GUSTY  
WINDS/SMALL HAIL DURING THU AFTERNOON. WITH THE LOSS OF DIURNAL  
HEATING...STORMS SHOULD WIND DOWN FAIRLY QUICKLY AROUND SUNSET.  
 

 
   
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
 
 
A COLD FRONT MOVES OFFSHORE THURSDAY EVENING WITH SCATTERED  
SHOWERS AND AND THUNDERSTORMS...BY LATE EVENING THE FRONT MOVES  
OFFSHORE ALLOWING CLEARING TO DEVELOP BEHIND THE FROPA. HIGH  
PRESSURE BUILDS INTO THE REGION FRIDAY AND FRIDAY NIGHT WHILE  
LOW PRESSURE DEVELOPS ALONG THE SOUTHERN NEW ENGLAND COAST.  
MODELS GENERALLY AGREE ON KEEPING THE NORTHERN FRINGE OF ANY  
RAIN ALONG OR JUST SOUTH OF THE NH AND ME COASTLINE. THERE COULD  
BE A BRIEF PERIOD OF SOME LIGHT RAIN REACHING THESE AREAS LATE  
FRI NIGHT INTO EARLY SAT IF THE TRACK SHIFTS SLIGHTLY NORTH.  
MOST AREAS NORTH AND WEST OF THE COAST SAT WILL LIKELY REMAIN  
PARTLY TO MOSTLY SUNNY. BY LATE SAT THE SYSTEM QUICKLY EXITS TO  
THE EAST ALLOWING HIGH PRESSURE AND A WARMER MORE ZONAL FLOW  
ALOFT TO DEVELOP FOR THE LAST HALF OF THE WEEKEND AND INTO NEXT  
WEEK. TEMPS WILL COMFORTABLE FRIDAY AND INTO THE WEEKEND WITH  
HIGHS IN THE 70S TO NEAR 80 BUT BY EARLY NEXT WEEK HIGHS IN THE  
80S CAN BE EXPECTED WITH AN INCREASE IN HUMIDITY.  
 

 
   
AVIATION /14Z WEDNESDAY THROUGH SUNDAY/
 
 
SHORT TERM...LIFR CONDITIONS WILL CONTINUE IN THE MAJOR RIVER  
VALLEYS...ESPECIALLY ACROSS NH THRU SUNRISE. CLEAR SKIES WILL  
ALLOW FOR DAYTIME HEATING TO QUICKLY LIFT AND DISSIPATE  
FOG...WITH VFR CONDITIONS EXPECTED INTO THE LATE EVENING. AN  
APPROACHING COLD FRONT WILL SPREAD SOME SCATTERED SHRA THRU THE  
AREA EARLY THU...BUT THESE SHOULD REMAIN VFR OR MVFR. THE COLD  
FRONT ITSELF MAY SPARK SOME AFTERNOON TSRA. BASED ON MORNING  
PRECIP AND MODEL TRENDS...THE BEST CHANCE FOR TSRA AND PERHAPS A  
STRONGER ONE OR TWO WOULD BE ACROSS THE SRN HALF OF NH. HOWEVER  
CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN TAFS AT THIS TIME.  
 
LONG TERM...MVFR CONDITIONS POSSIBLE IN EVENING SHOWERS AND  
SCATTERED TSTORMS ASSOCIATED WITH THE PASSAGE OF A COLD FRONT THU  
EVENING, OTHERWISE MAINLY VFR CONDITIONS THROUGH THE OUTLOOK  
PERIOD.  
 

 
   
MARINE
 
 
SHORT TERM...HIGH PRESSURE IN CONTROL TODAY WILL KEEP WINDS AND  
SEAS BELOW SCA THRESHOLDS. RETURN FLOW BEHIND THE DEPARTING HIGH  
ON THU WILL ALLOW FOR SEAS TO BUILD. IT IS POSSIBLE BY AFTERNOON  
SOME 5 FT SEAS COULD OCCUR...BUT MAINLY OUT BY JEFFREYS LEDGE.  
 
LONG TERM...SEAS AND WINDS REMAIN BELOW SMALL CRAFT ADVISORY  
LEVELS THURSDAY NIGHT THROUGH FRIDAY NIGHT. WINDS AND SEAS MAY  
BRIEFLY APPROACH SCA CONDITIONS SATURDAY DEPENDING ON THE EXACT  
TRACK OF LOW PRESSURE THAT PASSES SOUTHEAST OF THE AREA.  
 

 
   
GYX WATCHES/WARNINGS/ADVISORIES
 
 
ME...NONE.  
NH...NONE.  
MARINE...NONE.  
 

 
 

 
JC  
 
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