Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 270525
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
125 AM EDT THU AUG 27 2015

.SYNOPSIS...
COLD FRONT ALONG THE EAST MASSACHUSETTS COAST WILL MOVE OFFSHORE
TONIGHT. HIGH PRESSURE SLOWLY BUILDS OVER THE REGION INTO THIS
WEEKEND...BRINGING DRY AND SEASONABLE WEATHER. THE HIGH BUILDS
OFFSHORE BY EARLY NEXT WEEK...ALLOWING FOR THE RETURN OF
HAZY...HOT AND HUMID CONDITIONS.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
125 AM UPDATE...
SOME MID LEVEL CLOUDS HAVE MOVED INTO N MA AND MOISTURE IN THE
850-700 MB LAYER SUGGESTS A FEW CLOUDS ACROSS WESTERN AND N MA
OVERNIGHT. CURRENT FORECAST ON TRACK. MINS IN THE 50S...EXCEPT
60-65 URBAN CENTERS AND COASTAL AREAS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
THURSDAY...
UPPER TROUGH AXIS IS STILL OVER NEW ENGLAND WITH SOME CLOUD-LEVEL
MOISTURE LINGERING AROUND 850 MB. DAYTIME HEATING SHOULD CONVERT
THIS TO DIURNAL CU...BUT STILL MAINTAIN PARTLY TO MOSTLY SUNNY
SKIES. THE MOST CLOUDS WILL BE IN NORTHERN MASS. TEMPS AT 850 MB
WILL BE 10C-11C...WHICH SUPPORTS MAX SFC TEMPS IN THE UPPER 70S
AND LOWER 80S...COOLER IN THE HIGHER HILLS AND PARTS OF THE COAST.

THURSDAY NIGHT...
HIGH PRESSURE REMAINS IN CHARGE.  FAIR AND DRY WEATHER WITH MIN
TEMPS A COUPLE OF DEGREES COOLER THAN TONIGHT.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGHLIGHTS...

* MAINLY DRY AND WARM WITH COMFORTABLE HUMIDITY FRIDAY AND SAT
* LATE SUMMER HEAT AND HUMIDITY LOOKS TO RETURN NEXT WEEK

OVERVIEW...

12Z MEDIUM RANGE MODEL SUITE CONTINUES IN GOOD AGREEMENT THROUGH
A GOOD PORTION OF THIS FORECAST. TYPICAL SUMMER UPPER LEVEL
PATTERN DOMINATES...WITH AMPLIFIED RIDGE THAT WORKS SLOWLY E OUT
OF THE PLAINS STATES INTO CENTRAL CANADA INTO THIS WEEKEND...WHILE
RATHER FLAT FLOW REMAINS ACROSS THE NORTHEAST U.S.

AS TIME MOVES ON...THE HIGH AMPLITUDE RIDGE CONTINUES TO WORK E
TOWARD THE GREAT LAKES AND HUDSON BAY. DO NOTE A FEW WEAK SHORT
WAVES IN THE UPPER FLOW...BUT FEEL WITH LARGE SURFACE RIDGING AND
GOOD SUBSIDENCE THESE WILL PROVIDE LITTLE IF ANY PRECIP THROUGH
THE MIDDLE OF NEXT WEEK.

LAST SEVERAL RUNS OF THE OP GFS CONTINUE TO TRY AND DEVELOP A
SOMEWHAT MORE POTENT SHORT WAVE AS IT MOVES ALONG IN THE FLOW
AROUND THE SUN INTO MON TIMEFRAME. THE LAST COUPLE OF RUNS OF THE
ECMWF ALSO SHOWING A SMALL PROGRESSIVE UPPER CUTOFF LOW SLOWLY
MOVING E. HOWEVER...EACH MODEL HANDLES THE SURFACE CONDITIONS
RATHER DIFFERENTLY...WITH CHANCE FOR PRECIP REMAINING ON THE GFS
WHILE REMAINING DRY ON THE EC AND GGEM EARLY NEXT WEEK.

OVERALL...APPEARS THESE MINOR FEATURES PRESENT LITTLE IF ANY
PRECIP AS THE LARGE SURFACE HIGH ALONG THE EASTERN SEABOARD WORKS
OFFSHORE...ESTABLISHING ACROSS THE WESTERN ATLC. ALSO INTERESTING
TO NOTE THAT ALL THREE OP MODEL RUNS /GFS...GGEM AND ECMWF/ TRY TO
MOVE T.S. ERIKA OFF THE SE U.S. COAST AROUND TUE-WED...THOUGH
HOLDING IT OFFSHORE. SOMETHING TO KEEP AN EYE ON.

WENT ALONG WITH AVAILABLE MODEL GUIDANCE THROUGH THIS WEEKEND...
THEN TRANSITIONED OVER THE ENSEMBLES AS MODELS DIVERGE ON THEIR
INDIVIDUAL SOLUTIONS EARLY NEXT WEEK. OVERALL...IT DOES LOOK LIKE
A DRY FORECAST.

DETAILS...

FRIDAY AND SATURDAY...HIGH CONFIDENCE.

HIGH PRESSURE WILL DOMINATE ACROSS THE REGION INTO THIS WEEKEND.
EXPECT TEMPS TO RUN CLOSE TO OR A BIT WARMER THAN NORMAL. HIGHS
ON FRIDAY IN THE UPPER 70S TO LOWER 80S EXCEPT WHERE SEA BREEZES
SET UP HOLDING TEMPS DOWN A FEW DEGREES. WINDS SHIFT AROUND TO
S-SW ON SATURDAY...SO WILL SEE TEMPS RISE SEVERAL DEGREES HIGHER
THAN ON FRIDAY. READINGS WILL TOP OFF IN THE LOWER-MID 80S...
THOUGH DEWPTS WILL REMAIN IN THE MID 50S TO AROUND 60.

SUNDAY...LOW TO MODERATE CONFIDENCE.

12Z GFS CONTINUES TO PERSIST IN BRINGING CHANCE POPS ACROSS THE
REGION AS WEAK SHORT WAVE MOVES ACROSS...WHILE MOST OTHER GUIDANCE
REMAINS DRY. HOWEVER...AS MENTIONED ABOVE...DO NOTE SOME ENERGY
SLIDING TOWARD THE REGION ON THE EC AS WELL. SO...CONTINUED WITH
MENTION SLIGHT CHANCE POPS WITH BEST CHANCE DURING THE AFTERNOON
INTO THE EVENING WITH BEST DIURNAL HEATING.

MONDAY THROUGH WEDNESDAY...LOW TO MODERATE CONFIDENCE.

INDIVIDUAL MODELS DIVERGE DURING THIS TIMEFRAME AS UNCERTAINTY
CONTINUES WITH STRENGTH OF SHORT WAVES BEING DEPICTED ON EACH
MODEL AS THEY MOVE ALONG IN THE UPPER FLOW. HOWEVER...AS UPPER
RIDGE BUILDS FURTHER E AND LARGE SURFACE HIGH ESTABLISHES OFF THE
EASTERN SEABOARD...LOOKS LIKE LATE SUMMER HEAT AND HUMIDITY
INCREASES DURING THIS TIMEFRAME. EXPECT HIGHS MAINLY IN THE MID-
UPPER 80S THOUGH COULD SEE SOME 90+ DEGREES READINGS AS WELL. VERY
IMPRESSIVE WARM SIGNAL CONTINUES.

&&

.AVIATION /05Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH FRIDAY/...

THROUGH FRIDAY...HIGH CONFIDENCE. VFR. PATCHY FOG POSSIBLE LATE
TONIGHT.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. EXPECT SEA BREEZE TO
REMAIN JUST OFFSHORE TODAY. BETTER CHC OF A SEA BREEZE FRIDAY.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...HIGH CONFIDENCE.

FRIDAY NIGHT AND SATURDAY...MAINLY VFR. WEAK SEA BREEZES SHOULD
DEVELOP ALONG THE IMMEDIATE COASTS. LOW CHANCE FOR BRIEF PATCHY
LATE NIGHT/EARLY MORNING FOG ACROSS NORMALLY PRONE INTERIOR
VALLEYS.

SUNDAY...MAINLY VFR. LOW CHANCE FOR BRIEF LOCAL MVFR IN SCT
SHOWERS/TSTMS MAINLY AFTERNOON/EVENING AWAY FROM THE S COAST.

MONDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH THURSDAY NIGHT/...HIGH CONFIDENCE.

QUIET BOATING WEATHER WITH WINDS AND SEAS BELOW SCA THRESHOLDS
THROUGH THE PERIOD. WIND BECOMING WEST-NORTHWEST THROUGH THE
PERIOD.

OUTLOOK /FRIDAY THROUGH MONDAY/...HIGH CONFIDENCE.

EXPECT WINDS AND SEAS REMAINING BELOW SMALL CRAFT LEVELS THROUGH
MOST OF THE PERIOD.

SW WINDS MAY PICK UP DURING SUNDAY ON THE SOUTHERN OUTER WATERS
WITH SEAS POSSIBLY REACHING 5 FEET. WILL CONTINUE TO MONITOR IN
CASE A SMALL CRAFT IS NEEDED THERE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/EVT
NEAR TERM...KJC
SHORT TERM...WTB
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...WTB/EVT



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