Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 041722
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
122 PM EDT MON MAY 4 2015

.SYNOPSIS...
TODAY WILL BE THE WARMEST DAY SO FAR...BUT SHOWERS FOLLOW AHEAD
OF A COLD FRONT FOR TUESDAY. HIGH PRESSURE BUILDS OVER THE EASTERN
USA MIDWEEK WITH DRY WEATHER THROUGH FRIDAY AND WARMING
TEMPERATURES THROUGH THE WEEKEND. A COLD FRONT APPROACHES DURING
THE WEEKEND AND MAY BRING SCATTERED SHOWERS.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
120 PM UPDATE...

TEMPERATURES HAVE WARMED INTO LOW TO MID 80S ACROSS MUCH OF
SOUTHERN NEW ENGLAND EARLY THIS AFTERNOON...WHICH IS THE WARMEST
IT HAS BEEN SINCE LAST OCTOBER. MUCH OF SOUTH COAST...CAPE COD AND
ISLANDS HAVE BEEN HOLDING IN UPPER 50S AND LOWER 60S DUE TO
INFLUENCE OF COLDER OCEAN. EXPECT TEMPERATURES TO RISE A FEW MORE
DEGREES THROUGH LATE AFTERNOON.

STARTING TO SEE SOME CLOUDS FORM NEAR HIGHER TERRAIN...BUT THESE
CLOUDS WILL STILL ALLOW FOR PLENTY OF SUNSHINE THIS AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
HIGH PRES WILL GIVE WAY TO AN APPROACHING COLD FRONT FROM THE NW.
THIS FRONT WILL BE SLOWING AS IT BEGINS TO PARALLEL STEERING FLOW
ALOFT. THEREFORE...ASIDE FROM INCREASING HIGH-MID CLOUDS ACROSS
THE REGION ESPECIALLY AFTER MIDNIGHT IT WILL LIKELY TAKE UNTIL 09Z
OR LATER FOR ENOUGH MOISTURE FLUX AND LIFT ASSOCIATED WITH THE
FRONT TO YIELD -SHRA ACTIVITY MAINLY ACROSS NW MA. THIS BAND WILL
GRADUALLY SHIFT TO THE S THROUGH THE MORNING...SO A DAMP COMMUTE
IS EXPECTED FOR SOME. LOOKING AT BUFKIT PROFILES...SOUNDINGS ARE
RELATIVELY STABLE FOR THE OVERNIGHT AND MORNING TIMEFRAME SO WILL
RUN WITH JUST SHOWERS RATHER THAN INCLUDING ANY TSRA. THE
INCREASING CLOUDS AND LOW LVL MOISTURE SUPPORT EVEN MILDER MINS
THAN SUN NIGHT...MAINLY IN THE 50S ACROSS THE BOARD.

TUE...
SLOWING AND GRADUALLY DISSIPATING COLD FRONT WILL BE MAKING IT/S
WAY FROM N-S ACROSS THE REGION. IT/S TIMING IS SLOW ENOUGH THAT IT
WILL LIKELY BE JUST BARELY AT THE N BORDER OF MA BY 12Z AND ONLY
JUST OFF THE S COAST BY 00Z. THEREFORE...THERE WILL BE A FOCUS FOR
LIFT IN THE VICINITY PRETTY MUCH ALL DAY AND PWATS WILL INCREASE
TO AROUND 1.25 INCHES. THEREFORE...LIKELY SEE PLENTY OF -SHRA
ACTIVITY ACROSS THE REGION...ALTHOUGH A SLOW IMPROVEMENT WILL
BEGIN FROM N-S THROUGH THE AFTERNOON AS STRONG RIDGING MOVES IN
BEHIND THE EXITING FRONT.

THERE IS SOME QUESTION OF CONVECTIVE POTENTIAL. SOUNDINGS ARE
CONDITIONALLY UNSTABLE IN A NARROW CORRIDOR MAINLY THROUGH CT/RI
AND SE MA /IN ESSENCE WHERE BETTER EARLY MORNING HEATING IS
EXPECTED/. THIS WILL LIKELY YIELD CAPE VALUES ON THE ORDER OF
300-500J/KG BY THE AFTERNOON WITH MID LVL LAPSE RATES AROUND
6.5C/KM. THEREFORE...STILL CAN/T RULE OUT SOME ISOLATED THUNDER
MAINLY ACROSS THE S AND MAINLY DURING THE AFTERNOON HOURS. MAIN
ISSUE WILL BE A BRIEF HEAVY DOWNPOUR THANKS TO THE HIGHER PWAT
AIRMASS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... SHORTWAVE RACING ACROSS EASTERN CANADA PASSES NORTH
AND EAST OF SOUTHERN NEW ENGLAND MIDWEEK. UPPER RIDGE BUILDS OVER
THE EASTERN USA WHILE UPPER TROUGH DIGS OVER THE WESTERN USA. MODELS
SHOW A COUPLE OF SHORTWAVES MOVING THROUGH THE RIDGE NEXT WEEKEND
AND PUSHING A COLD FRONT INTO OR THROUGH OUR AREA. OVERALL A DRY
WARM PATTERN FOR SOUTHERN NEW ENGLAND THROUGH FRIDAY. MODELS SUGGEST
A COUPLE OF SHORTWAVES MOVING OVER THE RIDGE DURING NEXT WEEKEND BUT
AT TIMES FEATURE POPS WITH MOSTLY CLEAR SKIES...SO CONFIDENCE IN
PCPN IS LOW AT THIS TIME.

WE USED OUR USUAL BLEND OF LONG RANGE DATA. ONE DEPARTURE WAS WITH
TEMPERATURES...FOR WHICH THE MODEL DATA SEEMED 3-5F TOO COOL FOR THE
EXPECTED THERMAL PROFILE ALOFT.  WE ADJUSTED WEDNESDAY THROUGH
FRIDAY MAX TEMPS A LITTLE WARMER THAT GUIDANCE TO BE MORE
CONSISTENT WITH OTHER DATA.

THE DAILIES...

TUESDAY NIGHT... COLD FRONT ALONG THE SOUTH COAST MOVES FARTHER
OFFSHORE. HIGH PRESSURE BUILDS OVER NEW ENGLAND OVERNIGHT. ANY
LINGERING SHOWERS ALONG THE COAST SHOULD MOVE OFF. EXPECT CLEARING
SKIES AND A LIGHT NORTHEAST WIND.

WEDNESDAY THROUGH FRIDAY...SURFACE HIGH PRESSURE BUILDS OVER THE
REGION. MOISTURE PROFILES ARE MAINLY DRY ALTHOUGH CROSS SECTIONS
SHOW SOME HIGH LEVEL MOISTURE WHICH MAY BE THIN CIRRUS. CROSS
SECTIONS ALSO SHOW SOME LOW LEVEL MOISTURE THURSDAY NIGHT AND FRIDAY
NIGHT WHICH MAY BE FOG AND/OR STRATUS. MIXING PROFILES REACH TO 800
MB WEDNESDAY AND THURSDAY...AND BETWEEN 800 AND 850 MB FRIDAY. TEMPS
AT THE TOP OF THE MIXED LAYER SUPPORT 70S WEDNESDAY...WARMING TO 80
OR LOWER 80S BY FRIDAY. ONSHORE FLOW WILL KEEP COASTAL AREAS IN THE
60S. INLAND MAX TEMPS WERE ADJUSTED WARMER DURING THIS PERIOD BASED
ON EXPECTED TEMPERATURES ALOFT.

SATURDAY-SUNDAY...SHORTWAVES MOVE THROUGH THE UPPER RIDGE. THIS
DRAWS A COLD FRONT THROUGH NEW ENGLAND. MOISTURE IS LIMITED SATURDAY
BUT COULD GENERATE A SHOWER IN NORTHERN/WESTERN AREAS. BETTER CHANCE
OF SHOWERS SUNDAY AS THE FRONT MOVES THROUGH SOUTHERN NEW ENGLAND.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE THROUGH TUE NIGHT.

SW WINDS MAY BRING SOME 20-25KT GUSTS THROUGH EARLY EVENING ACROSS
INTERIOR...OTHERWISE VFR THROUGH TONIGHT. VFR CIGS TUE AS COLD
FRONT DROPS THROUGH SOUTHERN NEW ENGLAND...WITH SCATTERED SHOWERS
POSSIBLE. MAY SEE SOME MVFR CIGS NEAR S COAST TUE AFTERNOON. VFR
TUE NIGHT.

KBOS TAF...HIGH CONFIDENCE IN TAF.

KBDL TAF...HIGH CONFIDENCE IN TAF.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.

MAINLY VFR. AREAS OF FOG MAY DEVELOP EACH NIGHT BETWEEN MIDNIGHT AND
SUNRISE WITH LOCAL IFR CIGS/VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

THROUGH TODAY...HIGH CONFIDENCE.
SW WINDS MAY GUST TO AROUND 20KT NEAR SHORE THIS AFTERNOON.

TONIGHT INTO TOMORROW...MODERATE CONFIDENCE.
THE SW FLOW WILL SLOWLY GIVE WAY TO W FLOW AS A COLD FRONT CROSS
THE WATERS DURING THE TUE EVENING HOURS. WITH THE PERSISTENT SW
FLOW TODAY...SOME SUGGESTION WIND DRIVEN SEAS COULD APPROACH 5 FT
ON THE OCEAN WATERS...BUT DO NOT HAVE HIGH ENOUGH CONFIDENCE TO
ISSUE A SMALL CRAFT ADVISORY AT THIS TIME. THIS WILL NEED TO BE
MONITORED. CONDITIONS IMPROVE ON TUE IF THEY REACH CRITERIA AT
ALL...BUT SOME SHOWERS AND POSSIBLY EVEN A THUNDERSHOWER

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE MOVES OVER THE WATERS. WIND DIRECTIONS BECOME
SOUTHWEST BY FRIDAY...BUT SPEEDS REMAIN 15 KNOTS OR LOWER THROUGH
THE PERIOD. LIGHT FLOW WILL ALSO MEAN LIGHT SEAS WITH HEIGHTS BELOW
5 FEET THROUGH THE PERIOD. NO SMALL CRAFT HEADLINES ARE EXPECTED.

&&

.FIRE WEATHER...
RED FLAG WARNING REMAINS POSTED PRIMARILY FOR THE TERRAIN
INFLUENCE IN WESTERN MASSACHUSETTS. TEMPERATURES IN THE UPPER 70S
AND LOW 80S WILL COMBINE WITH DEWPOINTS IN THE UPPER 30S AND LOW
40S TO YIELD MIN RH VALUES AROUND 20 PERCENT THIS AFTERNOON.
SW WINDS 10 TO 15 MPH WILL OCCASIONALLY GUST TO 20-25 MPH THROUGH
7 PM.

SCATTERED SHOWERS EXPECTED TUE BUT RAINFALL AMOUNTS SHOULD BE
UNDER 0.25 INCH. LIGHT W/NW WINDS EXPECTED WITH MORE CLOUD COVER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MAZ002>004-
     008>012-026.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/DOODY
NEAR TERM...BELK/DOODY/JWD
SHORT TERM...DOODY
LONG TERM...WTB
AVIATION...WTB/DOODY/JWD
MARINE...WTB/DOODY
FIRE WEATHER...JWD



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