Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KBOX 211424
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1025 AM EDT TUE APR 21 2015

.SYNOPSIS...

MAINLY DRY AND BECOMING MILD THIS AFTERNOON WITH JUST A FEW BRIEF
SPOT SHOWERS POSSIBLE. A COLD FRONT WILL BRING SCATTERED
SHOWERS...AND PERHAPS EVEN AN ISOLATED THUNDERSTORM OR
TWO...WEDNESDAY AFTERNOON AND EVENING. UNSEASONABLY COOL WEATHER
FOLLOWS THURSDAY THROUGH THIS WEEKEND WITH JUST A SPOT SHOWER FROM
TIME TO TIME.

&&

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

1025 AM UPDATE...

NUMEROUS SHOWERS AND THUNDERSTORMS THAT WORKED ACROSS THE REGION
VERY EARLY THIS MORNING WERE LONG GONE.  OTHERWISE...A FAIR AMOUNT
OF CLOUDS REMAINED ESPECIALLY ACROSS THE INTERIOR.  THERE WERE ALSO
AREAS OF FOG THAT REMAINED ACROSS NORTHEAST MA AND CAPE/ISLANDS.

OVERALL...EXPECT GRADUAL IMPROVEMENT IN CEILINGS AND
VISIBILITIES INTO THIS AFTERNOON AS WESTERLY WINDS USHER DRIER LOW
LEVEL AIR INTO THE REGION.  SHOULD STILL SEE A FAIR AMOUNT OF
CLOUDS...BUT ALSO INCREASING PEEKS OF SUNSHINE.

AS FOR PRECIP CHANCES...MUCH OF THE DAY WILL BE DRY.  STILL MAY SEE
A FEW PASSING SHOWERS THROUGH THE AFTERNOON...ESPECIALLY ACROSS
NORTHWEST MA WHERE A BAND OF SHOWERS MAY CLIP THAT REGION OVER THE
NEXT FEW HOURS.  INSTABILITY LOOKS RATHER LIMITED SO DID NOT
INCLUDE THUNDER IN THE FORECAST.  HIGH TEMPS WILL BE MAINLY IN THE
60S AND ITS NOT OUT OF THE QUESTION THAT SOMEONE ACROSS
SOUTHEAST MA TOUCHES 70.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
A SHORTWAVE WILL BE APPROACHING FROM THE WEST...BRINGING A CHANCE
FOR SOME SHOWERS TO PORTIONS OF WESTERN MA BY DAYBREAK WEDNESDAY.
WITH A COLD FRONT HAVING ALREADY PASSED THROUGH OUR REGION LATE
THIS AFTERNOON...MODELS DO NOT SHOW MUCH RAINFALL AS INSTABILITY
IS RATHER LIMITED. MUCH OF TONIGHT SHOULD REMAIN DRY ACROSS
SOUTHERN NEW ENGLAND WITH SEASONABLE MINIMUM TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...

* SCATTERED SHOWERS WED WITH A LOW RISK OF THUNDER/SMALL HAIL
* SEASONABLY MILD TEMPERATURES WED
* UNSEASONABLY COOL THU-SUN WITH A SPOT SHOWER OR TWO AT TIMES

OVERVIEW...

OVERALL THE 12Z GUIDANCE IS IN GOOD AGREEMENT WITHIN THE MEDIUM AND
LONG RANGE. HOWEVER EXACT TIMING AND STRENGTH OF EACH SYSTEM STILL
NEEDS TO BE WORKED OUT.  UPPER LEVEL LOW WILL CONTINUE TO DOMINATE
THE REGION THROUGH THE EXTENDED...PINWHEELING BETWEEN THE GREAT
LAKES AND NEW ENGLAND. THIS SYSTEM WILL YIELD TO A MORE SHOWERY AND
COOLER FORECAST FOR THE REST OF THE WEEK AND INTO THE WEEKEND.

DETAILS...

* WEDNESDAY AND WEDNESDAY NIGHT...MODERATE CONFIDENCE.

STRONG SHORTWAVE WILL MOVE THROUGH THE FLOW ON WEDNESDAY DEVELOPING
A SURFACE LOW ACROSS HUDSON RIVER VALLEY AND INTO SOUTHERN NEW
ENGLAND. THIS LOW WILL BRING SCT RAIN SHOWERS AND ISOLATED THUNDER
TO THE AREA BY THE AFTERNOON HOURS. APPEARS WE MAY TRY TO WARM
SECTOR ALLOWING SURFACE TEMPS TO REACH INTO THE LOW TO MID 60S. THIS
WILL STEEPEN THE LAPSE RATES TO AROUND 7-8 C/KM AS 500 MB TEMPS ARE
-24C. MODEL GUIDANCE IS ALSO INDICATING THAT SOME SURFACE CAPE MAY
DEVELOP WHICH WILL HELP IN THUNDERSTORM DEVELOPMENT. IN FACT WE
COULD SEE SMALL HAIL/GRAUPEL AS FREEZING HEIGHTS WILL BE LOW
THANKS TO THE COLD POOL. STILL A LOT OF DETAILS TO WORK OUT BUT
SOMETHING TO WATCH IN THE COMING DAY.


* THURSDAY INTO MONDAY...MODERATE CONFIDENCE.

STRONG CUT OFF LOW WILL CONTINUE TO SPIN OVER THE NORTHEAST DURING
THIS TIME PERIOD. NEW ENGLAND COULD SEE A SEVERAL WAVES DEVELOP AND
PUSH THROUGH THE REGION. HOWEVER MAY SEE A LOT OF DIURNAL CU AND
DIURNAL SHOWERS DEVELOPING RATHER THAN WIDESPREAD RAIN. THESE
SHOWERS WILL BE DIURNALLY DRIVEN AS COLD POOL ALOFT WILL BE OVERHEAD
STEEPENING THE LAPSE RATES. AREAS THAT HAVE THE BEST CHANCE FOR
ANY PRECIP WILL BE NORTH OF THE PIKE...CLOSER TO THE LOW PRESSURE.

LASTLY EXPECT TEMPS TO BE ABOUT 5-10 F BELOW AVERAGE FOR THE WEEK
THANKS TO THE COOLER TEMPS ALOFT VIA THE COLD POOL. IN FACT SOME
AREAS MAY NOT SEE THE 60S FOR THE REST OF THE WEEK AND INTO THE
WEEKEND.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...

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

.SHORT-TERM /THROUGH TUESDAY/...

TODAY...MODERATE CONFIDENCE.  MVFR-IFR CIGS/VSBYS LINGERING ACROSS
MUCH OF THE REGION AT LATE MORNING.  TRENDS WILL BE FOR GRADUAL
IMPROVEMENT INTO THE AFTERNOON...BUT THIS PROCESS WILL BE SLOWEST
ALONG PORTIONS OF THE CAPE/ISLANDS WHERE IT MAY TAKE UNTIL MID TO
LATE AFTERNOON UNTIL IMPROVEMENT.  AGAIN...WHILE WE EXPECT
IMPROVEMENT TIMING IS UNCERTAIN.

TONIGHT...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS DESPITE THE
RISK FOR A SPOT SHOWER OR TWO.

KBOS TAF...MODERATE IN TAF BUT LOW CONFIDENCE IN TIMING.  SHOULD SEE
IMPROVEMENT TO MAINLY VFR CONDITIONS BY MID AFTERNOON.

KBDL TAF...MODERATE IN TAF BUT LOW CONFIDENCE IN TIMING.  SHOULD SEE
IMPROVEMENT TO MAINLY VFR CONDITIONS BY MID AFTERNOON.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

WED...MODERATE CONFIDENCE.  A COLD FRONT WILL BRING A ROUND OF
SCATTERED SHOWERS MAINLY WED AFTERNOON/EARLY EVENING.  LOW RISK FOR
EVEN A FEW RUMBLES OF THUNDER AND PERHAPS SMALL HAIL/GRAUPEL WITH
THE HEAVIEST SHOWERS.

THU/FRI/SAT...HIGH CONFIDENCE. MAINLY VFR. CONDITIONS COULD LOWER TO
MVFR QUICKLY IN A BRIEF DIURNALLY DRIVEN SHOWER OR TWO.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TONIGHT/...

WINDS HAVE DIMINISHED BELOW SCA CRITERIA...BUT SEAS REMAIN ABOVE
THRESHOLDS ACROSS THE OUTER-WATERS.  THEREFORE...SMALL CRAFT
HEADLINES CONTINUE INTO TONIGHT.  MAIN CONCERN THROUGH MID AFTERNOON
WILL BE AREAS OF FOG ESPECIALLY FROM NANTUCKET SOUND AND INTO OUR
SOUTHEAST WATERS.  EXPECT GRADUAL IMPROVEMENT THROUGH THE AFTERNOON.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

WEDNESDAY...HIGH CONFIDENCE. MODEST WEST TO SOUTHWEST FLOW EXPECTED
AHEAD OF A COLD FRONT...BUT SPEEDS WILL BE NEAR SCA ESP ACROSS THE
NEAR SHORE WATERS. A FEW SHOWERS WED AFTERNOON AND EVENING WITH A
LOW RISK OF AN ISOLATED THUNDERSTORM WITH SMALL HAIL.

THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE.  MODEST WESTERLY FLOW
AS A RESULT OF CLOSED LOW PRESSURE ACROSS QUEBEC.  ENOUGH COLD
ADVECTION OVER THE WATERS WILL BE PRESENT TO GENERATE PERIODS OF 25
KNOT WIND GUSTS.  MARGINAL SCA SEAS EXPECTED ACROSS THE OUTER-WATERS
AT TIMES...BUT WITH GOOD VISIBILITY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ235-237-
     250-254>256.
     SMALL CRAFT ADVISORY UNTIL NOON EDT WEDNESDAY FOR ANZ251.

&&

$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...FRANK
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...FRANK/BELK/DUNTEN
MARINE...FRANK/BELK/DUNTEN



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.