Area Forecast Discussion
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000
FXUS61 KBOX 031405
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1005 AM EDT THU SEP 3 2015

.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS NEW ENGLAND TODAY AND WILL BE
ACCOMPANIED BY SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS. CANADIAN HIGH PRESSURE BUILDS OVER NEW ENGLAND FRIDAY
AND INTO THE LABOR DAY WEEKEND. THE HIGH MOVES JUST OFFSHORE EARLY
NEXT WEEK YIELDING MAINLY DRY BUT WARMER THAN NORMAL TEMPERATURES.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
10 AM UPDATE...

FORECAST LOOKS ON TRACK THIS MORNING...ONLY EXCEPTION IS THE PATCH
OF MARINE STRATUS/FOG DRIFTING EASTWARD FROM LONG ISLAND AND
VICINITY TOWARDS BLOCK ISLAND. HAVE ADDED SOME CLOUD COVER AND
PATCHY FOG TO THE VICINITY OF BLOCK ISLAND THRU MIDDAY...THIS
MARINE CLOUD BANK SHOULD CONTINUE TO MIX/LIFT OVER THE NEXT COUPLE
OF HOURS.

OTHERWISE...PATCHY FOG OVER THE INTERIOR CONTINUES TO LIFT AND
DISSIPATE...THEN EXPECTING DIURNAL CUMULUS CLOUDS WITH
SCATTERED/ISOLATED SHOWERS/T-STORMS THIS AFTERNOON.

PREVIOUS DISCUSSION FOLLOWS...

===================================================================

LEFTOVER UPPER LVL CI DEBRIS FROM EARLY CONVECTION CONTINUES TO
SPILL ACROSS THE NRN TIER OF SRN NEW ENGLAND THIS MORNING.
OTHERWISE...CLEAR SKIES AND CALM CONDITIONS PREVAIL. THESE CLOUDS
MAY LIMIT SOMEWHAT THE RISK FOR EARLY MORNING FOG IN SPITE OF THE
DWPTS IN THE LOW-MID 60S. HOWEVER...SOME AREAS ALREADY REPORTING
MODEST FOG IN THE VALLEYS OF WRN CT/MA.

BACKDOOR COLD FRONT WILL BE SLIDING INTO THE REGION THROUGH THE
DAY TODAY...STALLING AS IT MEETS THE MORE ROBUST INCOMING SEA
BREEZE FRONT FROM THE S. BULK OF THE INSTABILITY IS
ELEVATED...WITHIN A CORRIDOR OF 6.0-7.0C/KM LAPSE RATES...WHICH
WILL SHIFT SE...THEN OFFSHORE IN THE EVENING. EXPECT CONVECTION TO
START ACROSS THE HIGHER TERRAIN IN VT/NH THANKS TO ELEVATED HEAT
SOURCE BETTER REALIZING THE AVAILABLE INSTABILITY. THEN IT WILL BE
A RACE AGAINST TIME AS THIS CONVECTION SHIFTS S AND INTERACTS WITH
THE VARIOUS FRONTS /COLD AND SEA BREEZE/ ACROSS SRN NEW ENGLAND.
AGREE WITH PREVIOUS FORECASTER THAT THE MOST LIKELY CORRIDOR TO
MAINTAIN SOME OF THIS CONVECTION WILL BE AROUND THE I-495 CORRIDOR
AND INTO RI...WHERE THE FRONTS ARE LIKELY TO MEET. PLENTY OF
INSTABILITY ALOFT WITH ML CAPES EXCEEDING 1000J/KG...BUT WITH THE
CORE OF BEST LAPSE RATES SHIFTING OFFSHORE THROUGH THE
EVENING...IT MAY STRUGGLE. THEREFORE...FEEL THAT CAPPING BOTH
T-STORM AND SHOWER ACTIVITY AT SCT STILL REMAINS THE BEST
FORECAST. PWATS NEAR 2 STD DEVIATIONS ABOVE NORMAL...BUT GIVEN THE
SCT NATURE IT/S POSSIBLE SEVERAL LOCATIONS STILL REMAIN DRY.

SHOULD ANY STORMS HOLD THROUGH THE EVENING...THE UPPER LVL
INSTABILITY WILL BE THE ONLY THING TO MAINTAIN UPDRAFTS AS SHEAR
IS VERY WEAK. THEREFORE...STILL NOT MENTIONING ANY ENHANCED
WORDING WITH THIS UPDATE AS HEAVY RAIN...GUSTY WINDS AND/OR HAIL
WOULD BE A VERY ISOLATED EVENT.

HEAT CONTINUES ESPECIALLY INLAND...ONSHORE FLOW WILL LIMIT HIGHS
FURTHER E. HIGHS RANGE FROM THE 90S W...TO LOW 80S NEAR SHORE.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT...
WITH BACKDOOR FRONT SLOWING AND GRADUALLY DIMINISHING AS IT MOVES
OFFSHORE...LINGERING RISK OF ISOLATED -SHRA WILL GIVE WAY TO DRIER
CONDITIONS LATE WITH LOSS OF DIURNAL SUPPORT. LITTLE CHANGE IN
AIRMASS OVERNIGHT SO WITH DWPTS IN THE 60S SOME FOG STILL POSSIBLE
OVER INTERIOR MA/CT ESPECIALLY WHERE/IF RAIN FALLS. ERN MA/RI WILL
BE UNDER THE INFLUENCE OF INCREASING PRES GRADIENT AND BREEZY
CONDITIONS DURING THE AM HOURS. LOTS OF CLOUD COVER...SO MINS
REMAIN IN THE 60S IN SPITE OF COOLER AIRMASS SPILLING OVER FROM
THE NE.

FRI...
BREEZY AND COOLER THANKS TO A COMBINATION OF ONSHORE FLOW AND H85
TEMPS DIPPING TO AROUND +12C BY THE AFTERNOON HOURS. THE HIGH
PRES BUILDING OVER WILL LEAD TO STRONG ENOUGH SUBSIDENCE TO LIMIT
BL DEPTH. THEREFORE...UNLIKELY MIXING TO H85...LIMITING HIGHS
MAINLY IN THE LOW 70S TO LOW 80S INLAND. LOW 70S WILL BE NEAR
SHORE...THANKS TO SST/S NEAR THESE VALUES. THE NE WINDS WILL
DIMINISH DURING THE AFTERNOON EVEN AS SKIES GRADUALLY CLEAR.

&&

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

* WARMER THAN NORMAL TEMPERATURES MOST OF THIS PERIOD
* MAINLY DRY WEATHER PREVAILS

SYNOPTIC OVERVIEW...

GEFS AND ECENS ENSEMBLES IN GOOD AGREEMENT THAT SUBTROPICAL RIDGE
FROM TEXAS TO THE NORTHEAST STATES WILL DOMINATE OUR WEATHER MUCH OF
THIS PERIOD. ITS NOT UNTIL THE MIDDLE OF NEXT WEEK THAT THE NORTHERN
STREAM JET BEGINS TO DESCEND SOUTHWARD AND ERODE THE NORTHERN
PERIPHERY OF THIS RIDGE. THUS OTHER THAN TEMPERATURES BRIEFLY AT OR
COOLER THAN NORMAL FRI NIGHT INTO SAT MORNING...THE REMAINDER OF
THIS FORECAST PERIOD WILL BE WARMER THAN NORMAL. IN FACT THE EURO
ENSEMBLES SUGGESTING 850 TEMPS WARMING TO +18C ACROSS SNE BY MON AND
TUE! GEFS AND DETERMINISTIC GUIDANCE JUST SLIGHTLY LESS AT
+16C/+17C. THIS WOULD SUPPORT HIGHS APPROACHING 90 AWAY FROM THE
SOUTH COAST. REGARDING PRECIP...SUBTROPICAL RIDGE WILL PROVIDE DRY
WEATHER MOST OF THIS PERIOD WITH THE NEXT CHANCE OF CONVECTION THE
MIDDLE OF NEXT WEEK AS NORTHERN STREAM JET ENERGY BEGINS TO BREAK
DOWN THE NORTHERN PERIPHERY OF THE RIDGE. POTENTIAL WILDCARD NEXT
WEEK REGARDING THE AMPLITUDE OF THE NORTHERN STREAM JET ACROSS THE
CONUS MAY BE LINKED TO TROPICAL STORM IGNACIO...AS IT HEADS
NORTHEAST TOWARD GULF OF ALASKA EARLY NEXT WEEK AND BECOMES ABSORBED
AND POTENTIALLY ENERGIZES THE NORTHERN STREAM.

DAILY DETAILS...

FRI NIGHT/SATURDAY...

ANOMALOUS 1025 MB ANTICYCLONE/SURFACE HIGH ADVECTS INTO SNE. THIS
MODIFIED CONTINENTAL POLAR AIRMASS WILL COMBINE WITH CLEAR SKIES AND
LIGHT WINDS TO YIELD COOL TEMPS FRI NIGHT/SAT AM. SOME OF THE
GUIDANCE SUGGESTING THE TYPICALLY COOLER LOCATIONS COULD SEE TEMPS
DIP INTO THE U40S! THIS DEEP LAYER RIDGE /H5 HEIGHTS OF 591 DM AND
1024 MB SFC HI/ OVER THE AREA WILL PROVIDE DRY WEATHER WITH TEMPS
REBOUNDING INTO THE U70S AND L80S SAT AFTN AFTER A COOL START TO THE
DAY. COMFORTABLE HUMIDITY WITH DEW PTS IN THE 50S.

SUNDAY AND MONDAY...

DEEP LAYER RIDGE REMAINS OVER THE AREA SO DRY WEATHER PREVAILS.
RIDGE AXIS IS ACROSS THE REGION SUNDAY AND THEN SLIDES JUST OFF THE
SOUTH COAST MON. THIS WILL RESULT IN A GRADUAL WARMING TREND SUN AND
MON HOWEVER HUMIDITY LOOKS TO REMAIN TOLERABLE WITH DEW PTS ONLY
CLIMBING INTO THE U50S AND L60S.

TUESDAY AND WEDNESDAY...

SUBTROPICAL RIDGE LINGERS ALONG THE EASTERN SEABOARD. ENSEMBLES AND
DETERMINISTIC GUIDANCE SUGGEST A WEAK FRONT APPROACHES TUE BUT MAY
JUST WASHOUT AS RIDGE WINS OUT. A MORE SIGNIFICANT FRONT MAY ARRIVE
MID TO LATE NEXT WEEK. THUS WARM AND HUMID WEATHER LIKELY TO LINGER
INTO TUE AND POSSIBLY WED.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
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.

10 AM UPDATE...

TODAY...MAINLY VFR. THERE IS A MARINE STRATUS DECK /WITH FOG/
DRIFTING EAST OFF LONG ISLAND THAT MAY PRODUCE LOWER CIGS/VSBYS ON
BLOCK ISLAND AND NEARBY SOUTH COASTAL WATERS...SHOULD GRADUALLY
MIX/LIFT THRU NOON TODAY. LATE AFTERNOON/EVENING WIDELY SCT
-SHRA/TSTMS POSSIBLE...WITH LOCALIZED LOWER CATEGORIES. WINDS
SHIFT FROM THE SW TO E-NE THROUGH THE DAY.

TONIGHT AND FRI...
MAINLY VFR AFTER ANY SHOWERS AND LATE NIGHT FOG TONIGHT BURN OFF.
BREEZY EARLY FRI.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA-BREEZE EXPECTED TO
DEVELOP BY MIDDAY.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

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

VFR THROUGH THE PERIOD. AREAS OF EARLY MORNING IFR CIGS/VSBYS
POSSIBLE IN FOG SATURDAY AND SUNDAY. LIGHT FLOW OVER THE WEEKEND
WITH SEA BREEZES POSSIBLE SATURDAY. INCREASING WEST-SOUTHWEST FLOW
SUNDAY-MONDAY.

&&

.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.

TODAY...
MARINE CLOUD/FOG BANK DRIFINT EAST FROM LONG ISLAND AND
VICINITY...WILL ALLOW FOR PATCHY FOG IN THE VICINITY OF BLOCK
ISLAND/LONG ISLAND SOUND AND WATERS SOUTH OF BLOCK ISLAND THRU
MIDDAY...POSSIBLY EARLY AFTERNOON. EXPECT THIS CLOUD/FOG BANK TO
SLOWLY MIX/LIFT OVER THE NEXT FEW HOURS.

OTHERWISE...HIGH PRES WILL MOVE E OF THE WATERS AS A COLD FRONT
BACKDOORS FROM THE GULF OF MAINE. MAINLY QUIET BOATING WEATHER
PREVAILS...BUT AN ISOLATED SHOWER OR T-STORM LATE TODAY MAY LEAD
TO LOCALIZED ROUGH CONDITIONS.

TONIGHT INTO EARLY FRI...
N-NE WINDS WILL GRADUALLY INCREASE THROUGH THE OVERNIGHT HOURS.
GUSTS MAY APPROACH 25-30 KT AT TIMES EARLY AM INTO ABOUT MID DAY.
SEAS INCREASE AS WELL...REACHING NEAR 5 FT FIRST ON THE E
WATERS...THEN THE OUTER SRN WATERS BY MID DAY. THEREFORE...SMALL
CRAFT ADVISORIES HAVE BEEN HOISTED FOR THIS RISK.

LATE FRI...
CONDITIONS WILL GRADUALLY RECEDE BUT SOME SMALL CRAFT ADVISORIES
MA LINGER AS SEAS TAKE A BIT LONGER TO DIMINISH.

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

FRI NIGHT THROUGH MONDAY...TRANQUIL BOATING WEATHER THIS PERIOD AS
1025 MB HIGH PRESSURE BUILDS OVER THE WATERS. WIND AND SEAS FRI
NIGHT DIMINISH OVER THE WEEKEND TO LIGHT/VARIABLE SATURDAY AND
SOUTHWEST SUNDAY-MONDAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM TO 8 PM EDT FRIDAY FOR
     ANZ231>235-237-254>256.
     SMALL CRAFT ADVISORY FROM 5 AM TO NOON EDT FRIDAY FOR ANZ230.
     SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT FRIDAY FOR ANZ236.
     SMALL CRAFT ADVISORY FROM 5 AM TO 6 PM EDT FRIDAY FOR ANZ250-
     251.

&&

$$
SYNOPSIS...NOCERA/DOODY
NEAR TERM...NOCERA/DOODY/NMB
SHORT TERM...DOODY
LONG TERM...NOCERA
AVIATION...NOCERA/DOODY
MARINE...NOCERA/DOODY/NMB


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