393  
FXUS61 KGYX 292348  
AFDGYX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAY ME  
748 PM EDT MON MAY 29 2023  
   
SYNOPSIS
 
 
A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH THE  
MIDDLE OF THIS WEEK WITH MODERATING TEMPERATURES TO WELL ABOVE  
AVERAGE. HIGH PRESSURE IS ALSO EXPECTED TO BRING IN SOME SMOKE  
AND HAZE FROM NOVA SCOTIA WILDFIRES, AT LEAST ON TUESDAY. A  
COLD FRONT WILL THEN CROSS LATE FRIDAY, BRINGING THE POTENTIAL  
FOR SCATTERED SHOWERS AND THUNDERSTORMS. COOLER MORE SEASONABLE  
TEMPERATURES WILL THEN RETURN BEHIND THIS FRONT FOR THE UPCOMING  
WEEKEND.  
 

 
   
NEAR TERM /UNTIL 6 AM TUESDAY MORNING/
 
 
745 PM...NOT MUCH TO DEAL WITH OVERNIGHT OTHER THAN TEMPS, AND  
SINCE THE SUN HASN'T QUITE SET ATTM, AND DECOUPLING ISN'T REALLY  
OCCURING YET EITHER, HARD TO SAY HOW THE OVERNIGHT MINS ARE  
DOING, SO REALLY ONLY CHANGED THE THE EVENING T/TD BASED ON  
CURRENT OBS. TDS HAVE DONE THEIR USUAL LATE AFT/EARLY EVE BUMP,  
BUT THAT DOESN'T HAVE A SIGNIFICANT ON RAD WHEN IT COMES TO  
RAD COOLING. SO, WILL STAY THE COURSE FOR NOW AS FAR AS FROST  
GOES, AND WILL NO MORE AT NEXT UPDATE AFTER 2200.  
 
PREVIOUSLY...PRESSURE RISES, SLACKENING GRADIENT FLOW, AND  
SUBSIDENCE ARE EXPECTED TONIGHT AS SURFACE HIGH PRESSURE  
ANCHORED OVER THE GULF OF MAINE INTO NOVA SCOTIA PHASES WITH AN  
UPPER LEVEL RIDGE PUSHING IN FROM THE GREAT LAKES REGION.  
COMBINED WITH CLEAR SKIES AND A DRY COLUMN, THIS WILL SET UP AN  
EXCELLENT RADIATIONAL COOLING NIGHT. THUS, DEW POINTS FROM TODAY  
WILL BE THE KEY TO OVERNIGHT LOW TEMPERATURES... WITH COOLEST  
STATISTICAL GUIDANCE AND MOS INDICATING WIDESPREAD 30S TO  
LOW-40S CAN BE EXPECTED. THIS IS TRICKY WRT THE POTENTIAL FOR  
FROST... SINCE USING THESE VALUES INDICATE POTENTIAL FOR PATCHY  
FROST IN MOST PLACES, BUT WITHOUT THE COVERAGE TO NECESSITATE AN  
ADVISORY.  
 
BASED ON A TENDENCY FOR NIGHTS LIKE THIS TO COOL WELL PAST EVEN  
THE COOLEST GUIDANCE, ESPECIALLY RECENTLY, AND IN SPITE OF THE  
LIMITED NIGHT TIME WITH SUNRISE AROUND 5 AM... HAVE DECIDED TO  
TAKE TEMPERATURES DOWN FURTHER IN VALLEYS THAT CLIMATOLOGICALLY  
TEND TO DO SO, INCLUDING THE UPPER ANDROSCOGGIN AND CONNECTICUT  
RIVER VALLEYS AND THE SANDY/LOW-LYING SACO RIVER VALLEY. THUS  
HAVE GONE WITH A FROST ADVISORY FOR THESE LOCATIONS. EVENING  
SHIFT WILL HAVE TO MONITOR TRENDS IN MODEL GUIDANCE AND OBSERVED  
DEW POINTS FOR POTENTIAL EXPANSION.  
 

 
   
SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/
 
 
HIGH PRESSURE REMAINS ENTRENCHED OVER THE GULF OF MAINE AND  
SOUTHERN NEW ENGLAND ON TUESDAY, BUILDING AND SINKING SOUTH  
THROUGH THE DAY TO OVERNIGHT AND PRODUCING A SOUTHERLY FLOW  
OVER THE FORECAST AREA. OTHER THAN A FEW HIGH LEVEL CLOUDS FROM  
A WEAK WAVE DROPPING TOWARD THE SOUTHEAST OVER EASTERN  
CANADA/NORTHERN NEW ENGLAND... WE'LL HAVE ANOTHER SUNNY DAY  
LEADING TO NICE MIXING, AT LEAST TO START, BEFORE THE SEA BREEZE  
PUSHES ASHORE. HIGHS WILL DEPEND ON HOW QUICKLY THE SEA BREEZE  
ARRIVES, WITH WESTERN LOCATIONS WARMING TO AROUND 80 BUT THE  
COAST QUICKLY PLATEAUING OR REVERSING THE DIURNAL TREND IN THE  
60S. STEADY GRADIENT OF 70S READING SEPARATES THESE TWO.  
 
A QUICK GLANCE AT VISIBLE SATELLITE (AND NEWS STATIONS) TODAY  
SHOWS SIGNIFICANT FIRE ACTIVITY ONGOING TO OUR EAST IN NOVA  
SCOTIA. EXAMINING HRRR- AND RAP-SMOKE FIELDS... SUBSIDENCE AND  
ANTICYCLONIC FLOW FROM THE HIGH PRESSURE CIRCULATION IN THE  
GULF IS FORECAST TO BRING SMOKE TO THE SURFACE AND ADVECT TOWARD  
INTO NEW ENGLAND TUESDAY MORNING. THE STABLE AIR IN THE SEA  
BREEZE IS PRESENTLY MODELED TO BRING THE SMOKE ASHORE. IMPACTS  
ARE UNCERTAIN RIGHT NOW, BUT AT LEAST A SMELL AND/OR THICKER  
HAZE MAY BE NOTICEABLE.  
 
FOR THE OVERNIGHT FORECAST... ANTICYCLONIC FLOW EVENTUALLY  
ADVECTS IN HIGHER DEWPOINTS FROM THE SOUTH BY WAY OF THE OHIO  
VALLEY, RESULTING IN SOMEWHAT WARMER LOW TEMPERATURES IN THE  
40S. SUBSIDENCE AND DECOUPLING MAY CAUSE SMOKE TO HUG SURFACE...  
BUT AGAIN, THE IMPACTS ARE UNCERTAIN.  
 

 
   
LONG TERM /WEDNESDAY THROUGH MONDAY/
 
 
OVERVIEW: A LARGE DOME OF HIGH PRESSURE WILL REMAIN OVER THE REGION  
THROUGH MUCH OF THE WEEK BEFORE A COLD FRONT CROSSES ON FRIDAY.  
MODERATING TEMPERATURES TO WELL ABOVE AVERAGE ARE EXPECTED AHEAD OF  
THIS FRONT WITH MORE SEASONABLE TEMPERATURES RETURNING BEHIND THE  
FRONT FOR THE UPCOMING WEEKEND.  
 
IMPACTS: NEAR RECORD HIGH TEMPERATURES POSSIBLE ON BOTH WEDNESDAY  
AND THURSDAY. THE LACK IN APPRECIABLE RAINFALL MAY RESULT IN AN  
EXPANSION OF ABNORMALLY DRY CONDITIONS.  
 
FORECAST DETAILS: SURFACE HIGH PRESSURE WILL BE CENTERED TO OUR  
SOUTH ON WEDNESDAY, PROMOTING WARM SOUTHWESTERLY FLOW AS 925MB  
TEMPERATURES CLIMB TO AROUND +21C. LARGE SCALE SUBSIDENCE WILL ALLOW  
FOR ANOTHER DAY OF MAINLY SUNNY SKIES WITH ABOVE AVERAGE  
TEMPERATURES INTO THE MIDDLE TO UPPER 80S AWAY FROM THE COAST.  
CLOSER TO THE COAST DEVELOPING ONSHORE FLOW WILL KEEP HIGH  
TEMPERATURES INTO THE 60S ACROSS THE MID-COAST TO THE 70S FROM  
PORTLAND AND POINTS SOUTH. CLEAR SKIES AND LIGHT WINDS ON WEDNESDAY  
NIGHT WILL ALLOW FOR SOME RADIATIONAL COOLING WITH LOWS BOTTOMING  
OUT INTO THE UPPER 40S TO LOWER 50S. THE PEAK OF THE WARMTH THEN  
LOOKS TO ARRIVE ON THURSDAY WITH WAA ALLOWING 925MB TEMPERATURES  
TO APPROACH +24C. THIS COMBINED WITH SUNNY SKIES AND AFTERNOON  
MIXING WILL RESULT IN NEAR RECORD HIGHS INTO THE LOWER TO  
PERHAPS MIDDLE 90S AWAY FROM THE COASTLINE WITH 70S AND LOW 80S  
ALONG THE COAST. HEAT INDICES DO NOT LOOK TO BE A FACTOR,  
HOWEVER, AS TDS ARE LIKELY TO LARGELY REMAIN BELOW 60 DEGREES  
BUT IT MAY FEEL A LITTLE HUMID. THURSDAY NIGHT WILL BE VERY WARM  
WITH READINGS LIKELY NOT FALLING BELOW 60 DEGREES ACROSS THE  
URBAN CORRIDORS AND PERHAPS EVEN PORTIONS OF THE INTERIOR.  
 
ONE MORE UNSEASONABLY WARM DAY IS THEN EXPECTED ON FRIDAY AHEAD OF  
AN APPROACHING COLD FRONT FROM THE NORTH. AHEAD OF THIS FRONT,  
HIGHS WILL ONCE AGAIN REACH THE MIDDLE TO UPPER 80S WITH  
READINGS INTO THE LOWER 90S LIKELY ACROSS SOUTH-CENTRAL NH.  
CURRENT GUIDANCE INDICATES THE AFOREMENTIONED COLD FRONT MAY  
CROSS AFTER PEAK HEATING BUT DEPENDING ON THE TIMING OF THIS  
FRONT THUNDERSTORMS WILL BE POSSIBLE GIVEN THE VERY WARM  
PRECEDING AIRMASS. A RETURN TO MORE SEASONABLE TEMPERATURES IS  
THEN EXPECTED FOR THIS WEEKEND WITH DRY WEATHER CONDITIONS.  
ANOTHER FRONTAL SYSTEM MAY THEN APPROACH THE AREA EARLY NEXT  
WEEK.  
 

 
   
AVIATION /00Z TUESDAY THROUGH SATURDAY/
 
 
SHORT TERM...VFR ALL TERMINALS WITH VERY FEW CLOUDS TO SPEAK OF  
AND FLOW VEERING SOUTHEASTERLY AT ALL TERMINALS THROUGH THIS  
EVENING. MOST PLACES GO CALM TONIGHT. SOUTHERLY FLOW ON TUESDAY  
WILL BE MOST PRONOUNCED ALONG THE COAST AND OVER EASTERN  
TERMINALS PEAKING AROUND 10-15 KTS, WITH LIGHTER FLOW FOR  
WESTERN TERMINALS. SMOKE FROM FIRES IN NOVA SCOTIA MAY IMPACT  
VISIBILITY WITH THE SEA BREEZE THROUGH THE AFTERNOON, BUT THE  
DEGREE OF IMPACT IS UNCERTAIN. LIGHT AND VARIABLE OR CALM FLOW  
IS EXPECTED TUESDAY NIGHT WITH SOME POTENTIAL FOR VALLEY FOG.  
 
LONG TERM...WIDESPREAD VFR CONDITIONS EXPECTED THROUGH THURSDAY  
WITH DAILY SEA BREEZE CHANCES ACROSS COASTAL TAF SITES INCLUDING  
KPSM, KPWM, AND KRKD. A COLD FRONT WILL THEN ARRIVE LATE ON  
FRIDAY, BRINGING SCATTERED SHRA AND PERHAPS TSRA. VFR CONDITIONS  
WILL THEN RETURN FOR THE UPCOMING WEEKEND.  
 

 
   
MARINE
 
 
SHORT TERM...HIGH PRESSURE BUILDS OVER THE GULF OF MAINE THROUGH  
TONIGHT AND SHIFTS JUST SOUTH TUESDAY INTO TUESDAY NIGHT...  
ALLOWING SOUTHEASTERLY WINDS TODAY TO VEER SOUTHERLY TO  
SOUTHWESTERLY, EXCEPT FOR IN SEA BREEZE CIRCULATIONS. WINDS AND  
SEAS ARE EXPECTED TO REMAIN BELOW SCA THRESHOLDS.  
 
LONG TERM...WINDS AND SEAS WILL LARGELY REMAIN BELOW SCA  
THRESHOLDS THROUGH THURSDAY. A COLD FRONT WILL THEN CROSS OVER  
THE WATERS EITHER LATE FRIDAY OR FRIDAY NIGHT, PERHAPS BRINGING  
A PERIOD OF SCA LEVEL WINDS ALONG WITH SCATTERED SHOWERS.  
 

 
   
CLIMATE
 
 
RECORD HIGH TEMPERATURES ARE POSSIBLE ON BOTH WEDNESDAY AND  
THURSDAY OF THE UPCOMING WEEK. BELOW ARE THE RESPECTIVE HIGH  
TEMPERATURE RECORDS FOR EACH DAY.  
 
PORTLAND, ME WED: 94 (1987) THURS: 90 (2013)  
AUGUSTA, ME WED: 91 (2013) THURS: 92 (2013)  
CONCORD, NH WED: 94 (2013) THURS: 94 (2013)  
 

 
   
GYX WATCHES/WARNINGS/ADVISORIES
 
 
ME...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EDT TUESDAY FOR  
MEZ007-008-012-018.  
BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR  
MEZ023>028.  
NH...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EDT TUESDAY FOR  
NHZ001-002-004.  
BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR NHZ014.  
MARINE...NONE.  
 

 
 

 
SYNOPSIS...  
NEAR TERM...CASEY/CEMPA  
SHORT TERM...CASEY  
LONG TERM...TUBBS  
AVIATION...  
MARINE...  
CLIMATE...  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab ME Page
The Nexlab NH Page Main Text Page