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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1005 PM EDT TUE MAY 26 2015

.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL INCREASE THROUGH TOMORROW.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY...
WITH WEDNESDAY AND THURSDAY HAVING THE HIGHER POTENTIAL FOR
STRONG STORMS.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

1000 PM UPDATE...

ANY LEFT OVER SHOWERS HAVE DISSIPATED THIS EVENING. SOUTHERN NEW
ENGLAND CONTINUES TO REMAIN IN THE WARM MOIST SECTOR AS WARM FRONT
IS WELL NORTH WITH A COLD FRONT WELL TO THE WEST. WE HAVE ALREADY
STARTED TO TAP INTO THE GULF MOISTURE SO PWATS ARE ON THE INCREASE
AS WELL. LOW CONFIDENCE IF ANY SHOWER WILL DEVELOP OVERNIGHT AS
WE DO HAVE SOME ELEVATED INSTABILITY...BUT LACK THE TRIGGER
MECHANISM. 

TEMPERATURES ARE SLOW TO DROP THIS EVENING WITH MANY SITES STILL
IN THE 70S AWAY FROM THE SOUTH COAST/CAPE AND ISLANDS. BIGGEST
QUESTION IS THE POTENTIAL FOR FOG. VSBYS ARE SLOWLY DROPPING
ACROSS ACK AND MVY...BUT FEEL THAT STRATUS MAY BE THE BIGGEST
ISSUE OVERNIGHT. WILL WAIT AND SEE LATEST FORECAST SOUNDINGS TO
DETERMINE FOG POTENTIAL...BUT RIGHT NOW HAVE A LOW CONFIDENCE. 

PREVIOUS DISCUSSION...

TONIGHT...THE UPPER RIDGE OVER THE EASTERN SEABOARD WILL START TO 
BREAK DOWN WHICH WILL ALLOW FOR BETTER MOISTURE AND INSTABILITY OVER 
SOUTHERN NEW ENGLAND.  THIS COULD LEAD TO A FEW SPRINKLES OR LIGHT 
RAIN SHOWERS OVERNIGHT.  MOST OF THE MODEL GUIDANCE WAS DRY BUT THE 
GFS HAS BEEN INDICATING NOT JUST SPRINKLES BUT A GOOD TWO TENTHS OF 
AN INCH OF PRECIP.  FEEL THIS MAY BE SOME CONVECTIVE FEEDBACK FROM 
THE CONVECTION OVER NEW YORK AND PA THIS EVENING.

OTHERWISE...EXPECT SOME CLOUDINESS AND THAT WITH THE MOIST 
SOUTHWESTERLY WINDS WILL KEEP TEMPERATURES FROM FALLING TOO MUCH.  
EXPECT LOW TEMPERATURES MAINLY IN THE 60S.  THAT WARM...MOIST AIR 
FLOWING OVER THE COLDER OCEAN WILL LIKELY RESULT IN AREAS OF DENSE 
FOG OVER THE OCEAN AND BLEEDING ONTO THE SOUTH COAST...CAPE...AND 
ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...ANOTHER WARM AND MUGGY DAY FOR SOUTHERN NEW ENGLAND WITH 
TEMPERATURES TOPPING OUT IN THE UPPER 80S IN THE CONNECTICUT AND 
MERRIMACK VALLEYS WITH MID 80S ELSEWHERE.  EXCEPTION TO THIS IS 
ALONG THE SOUTH COAST...CAPE...AND ISLANDS WHERE BOTH ONSHORE WINDS 
AND PERHAPS LINGERING MARINE STRATUS AND FOG WILL KEEP TEMPERATURES 
FROM CLIMBING.  EXPECT HIGH TEMPERATURES IN THE 60S IN THESE 
LOCATIONS.

THIS LOOKS LIKE THE BETTER DAY FOR SOME SHOWERS AND THUNDERSTORMS TO 
AFFECT SOUTHERN NEW ENGLAND.  HOWEVER...THIS DOESN/T APPEAR TO OCCUR 
UNTIL LATE AFTERNOON AND EVENING.  INSTABILITY IS A BIT BETTER THAN 
IT WAS TODAY BUT IS STILL SOMEWHAT LACKING AND MID LEVEL LAPSE RATES 
LEAVE PLENTY TO BE DESIRED.  THE MAIN FOCUS FOR STORMS WILL BE OVER 
NEW YORK AND PENNSYLVANIA WHERE THE BETTER INSTABILITY AND FOCUSING 
WILL BE.  THESE STORMS...MUCH LIKE TODAY...WILL LIKELY MOVE INTO THE 
WESTERN PART OF THE CWA TOWARDS THE LATE AFTERNOON/EARLY EVENING.  
WHILE THESE STORMS HAVE THE POTENTIAL TO BE STRONG TO SEVERE...THE 
MOST LIKELY THREATS WITH THESE STORMS ARE HEAVY DOWNPOURS AND GUSTY 
WINDS.  

WEDNESDAY NIGHT...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO LAST 
INTO THE EVENING AS WIND SHEAR INCREASES WITH A STRONG LOW LEVEL JET 
MOVING OVER SOUTHERN NEW ENGLAND.  ANOTHER WARM NIGHT IN STORE WITH 
LOWS IN THE 60S.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
OVERVIEW AND MODEL PREFERENCES... 

TO START OFF...MEDIUM RANGE MODELS AND ENSEMBLES KEEP OVERALL UPPER 
LEVEL PATTERN IN PLACE ACROSS THE LOWER 48...WITH RIDGING ALONG OR 
JUST E OF THE EASTERN SEABOARD AND TROUGHING ACROSS THE ROCKIES INTO 
THE SOUTHWEST. MODEL TRENDS CONTINUE TO SIGNAL SLOW DEAMPLIFICATION 
OF THE UPPER PATTERN GOING INTO THIS WEEKEND...WITH RIDGE AXIS 
FLATTENING OUT ACROSS THE NORTHEAST AS A SURFACE FRONT THAT TRIES TO 
WORK ACROSS THE REGION WASHES OUT DURING FRIDAY. BERMUDA HIGH RE-
ESTABLISHES FOR EARLY THIS WEEKEND WHILE ANOTHER FRONT WORKS SE OUT 
OF QUEBEC. THIS FRONT LOOKS STRONG ENOUGH TO WORK SLOWLY SE AS THE 
WESTERN ATLC RIDGE SHIFTS S AND UPPER TROUGHING TAKES OVER ACROSS 
THE NORTHERN STREAM. BIG QUESTION WILL BE WHETHER THE FRONT WILL 
CLEAR OFF THE S COAST EARLY NEXT WEEK OR WILL IT STALL CLOSER TO OR 
OVER SOUTHERN AREAS. 

USED A BLEND OF AVAILABLE GUIDANCE FOR THIS FORECAST PACKAGE... 
THOUGH DID LEAN TOWARD MORE TOWARD THE ENSEMBLES FROM THIS WEEKEND 
ONWARD DUE TO TIMING DIFFERENCES WITH THE APPROACHING FRONT. FOR THE 
LATTER TIMEFRAME...LEANED CLOSER TO THE SLOWER ECMWF AND ECENS 
MEANS. 

DETAILS...

THURSDAY...WILL SEE LEFTOVER SCT SHOWERS/TSTMS ACROSS WESTERN AREAS 
THU MORNING WITH PWATS ON ORDER OF AROUND 1.5 INCHES. THE FRONT 
SHIFTS S TAKING THE HIGHER PWAT AIR WITH IT...SO EXPECT THE PRECIP 
TO TEND TO WEAKEN THOUGH WILL LINGER WHERE MILDER TEMPS ARE THANKS 
TO DIURNAL INFLUENCES. INSTABILITY ALSO SHIFTS OFFSHORE AND WEAKENS 
SO EXPECT ANY THUNDERSTORMS TO TAPER OFF BY AROUND MIDDAY. BEST SHOT 
FOR PRECIP WILL BE FROM THE MERRIMACK VALLEY SE ACROSS CENTRAL MA TO 
THE MID AND LOWER CT VALLEY. CAN NOT RULE OUT A FEW QUICK DOWNPOURS 
THROUGH MIDDAY WITH THE HIGHER PWAT AIRMASS. WILL SEE AREAS OF 
FOG...LOCALLY DENSE...DEVELOP ACROSS S COASTAL AREAS THU NIGHT INTO 
FRI MORNING. 

FRIDAY...MODELS STARTED TO SIGNAL DRIER AIR WORKING IN ON MONDAY... 
BUT MOST OF THE MODEL SUITE HAS HIGH PRES RIDGE BUILDING S OUT OF 
QUEBEC SO EXPECT A DRY BUT MILD DAY. DEWPTS DROP A BIT...DOWN TO THE 
50S...BUT WILL BEGIN TO RISE AGAIN FRI NIGHT. WILL SEE A LIGHT E-SE 
WIND FLOW SO WILL BE COOLER ALONG THE COAST...HIGHS MAINLY IN THE 
70S EXCEPT 65-70 ACROSS COASTAL AREAS...RANGING TO THE LOWER TO MID 
80S ACROSS THE CT VALLEY.  

SATURDAY...HIGH PRESSURE REPOSITIONS OFF THE EASTERN SEABOARD SO SW 
WINDS KICK IN AGAIN BRINGING A RETURN TO MORE HUMID AIR. ANOTHER 
COLD FRONT START TO APPROACH OUT OF GREAT LAKES AND WESTERN QUEBEC. 
ALSO NOTING INCREASING INSTABILITY PARAMETERS AHEAD OF THE FRONT... 
WITH K INDICES RISING TO THE LOWER-MID 30S AND TQ VALUES IN THE 
UPPER TEENS SO COULD SEE SOME ELEVATED CONVECTION WHICH COULD LAST 
INTO SAT NIGHT. BEST LIFT MOVES CLOSER DURING LATE SAT/SAT NIGHT SO 
WILL SEE SCT SHOWERS/THUNDERSTORMS DEVELOP. A PWAT SWATH OF 1.6 TO 
1.75 INCHES PUSHES OUT AHEAD OF THE FRONT...SO MAY SEE SOME HEAVIER 
DOWNPOURS WITH ANY CONVECTION.  WILL SEE QUITE A BIT OF SUNSHINE 
EARLY SATURDAY...SO TEMPS WILL REBOUND TO THE 80S FOR MOST LOCATIONS 
EXCEPT THE LOWER-MID 70S ALONG S COASTAL AREAS. 

SUNDAY...COLD FRONT SLOWLY ACROSS THE REGION SUNDAY MORNING...THEN 
REACHES THE S COAST BY SUNDAY NIGHT. EXPECT CHANCE SHOWERS AND 
THUNDERSTORMS. STILL SOME TIMING ISSUES BETWEEN THE GFS AND ECMWF
BUT A BIT BETTER FOR THIS TIMEFRAME. WITH THE SLOW MOVEMENT OF THE
FRONT...EXPECT SCT PRECIP TO CONTINUE THROUGH SUN NIGHT.

MONDAY-TUESDAY...SOMEWHAT LOWER CONFIDENCE DUE TO TIMING AND 
PLACEMENT DIFFERENCES WITH THE FRONT AND WHETHER IT STALLS NEAR THE 
S COAST OR OFFSHORE. AT THIS POINT...KEPT CHANCE POPS ACROSS CENTRAL 
AND SOUTHERN AREAS THROUGH MIDDAY THEN SHOULD PUSH JUST OFFSHORE BUT 
MAY LINGER ACROSS THE ISLANDS THROUGH MOST OF THE DAY SUNDAY. MAY 
SEE SOME THUNDERSTORMS EARLY...THEN INSTABILITY WORKS OFFSHORE BUT 
COULD STILL SEE SOME SHOWERS WHILE HIGH PRES MOVES ACROSS NORTHERN 
NEW ENGLAND. 

HAVE KEPT SLIGHT CHANCE POPS GOING FOR SOUTHERN AREAS INTO TUESDAY 
AS FRONT LOOKS TO LINGER...THEN MAY TRY TO MAKE A RUN BACK NE AS THE 
HIGH PUSHES OFF INTO THE GULF OF MAINE.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

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

TONIGHT...MODERATE CONFIDENCE. ANY LEFTOVER SHOWERS ACROSS NW MA
SHOULD DISSIPATE BY 03Z...BUT MAY PRODUCE BRIEF MVFR CIGS/VSBYS.
OTHERWISE...MAINLY VFR TO START...THEN DETERIORATING TO MVFR-IFR
IN AREAS OF FOG ALONG THE SOUTH COAST...CAPE...AND ISLANDS. COULD
SEE PASSING SHOWER OVERNIGHT.

WEDNESDAY...MODERATE CONFIDENCE. IFR ALONG THE SOUTH COAST DURING
THE MORNING SHOULD PUSH OFFSHORE. ANTICIPATE VFR CONDITIONS ACROSS
THE INTERIOR... DROPPING TO MVFR WITHIN ANY -SHRA/-TSRA THAT
DEVELOPS. EXPECT SW WINDS TO GUST UP TO 20-25 KT AT TIMES MAINLY
ACROSS RI/SE MA.

WEDNESDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS DETERIORATE TO
IFR ALONG THE SOUTH COAST...CAPE...AND ISLANDS AS MARITIME FOG AND
STRATUS ROLLS BACK IN.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. 
 
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. COULD SEE CONDITIONS DROP
TO MVFR WITHIN A POP-UP THUNDERSTORM TODAY.

OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.

THURSDAY...MAINLY VFR. WILL SEE SCT -SHRA/TSRA WITH LOCAL MVFR-IFR 
CONDITIONS. EXPECT AREAS OF FOG DEVELOP DURING THE LATE NIGHT/EARLY 
MORNING PERIOD WITH IFR-LIFR VSBYS.

FRIDAY...VFR. MAY SEE LOCAL MVFR-IFR CONDITIONS EARLY FRI MORNING 
ALONG S COAST IN PATCHY FOG...THEN WILL LOWER AGAIN LATE FRI 
NIGHT/SAT MORNING TO MVFR-IFR. 

SATURDAY...PATCHY FOG EARLY SAT MORNING WITH MVFR-IFR CONDITIONS
WILL IMPROVE. SCT SHRA/TSRA SAT THROUGH SAT NIGHT WITH LOCAL MVFR-
IFR CONDITIONS. SW WINDS GUSTING TO 20-25 KT MAINLY ALONG THE COAST 
SAT AFTERNOON/EVENING.

SUNDAY...SCT SHOWERS TSTMS LINGER THROUGH SUNDAY...BUT SHOULD END 
SUN NIGHT. MAY SEE BRIEF MVFR CONDITIONS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

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

SMALL CRAFT ADVISORIES ARE UP THROUGH TONIGHT...MAINLY ON THE
OUTER WATERS FOR SEAS AND SOUTHWESTERLY WINDS. SEAS WILL CLIMB TO
5 FEET AND REMAIN THERE THROUGH THE PERIOD. SMALL CRAFT ADVISORIES
WILL EXPIRE AT MIDNIGHT FOR THE INNER WATERS. SOUTHWESTERLY WINDS
WILL DIMINISH...BUT MAY LINGER FOR A FEW HOURS AFTER SUNSET.

IN ADDITION...AREAS OF DENSE FOG ARE LIKELY TO DEVELOP ON THE
WATERS TONIGHT...SUBSTANTIALLY REDUCING VISIBILITIES.

OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.

THURSDAY...EXPECT SW WINDS GUSTING TO AROUND 20 KT. SEAS BUILD TO 
AROUND 5 FT ACROSS THE SOUTHERN WATERS TO THE OUTER WATERS E OF CAPE 
COD...BUT SHOULD SUBSIDE BELOW 5 FT THU NIGHT. VSBYS REDUCED IN 
AREAS OF FOG...LOCALLY DENSE OFFSHORE BOTH THU AND FRI NIGHTS.

FRIDAY...LIGHT N-NE WINDS BECOME E DURING THE DAY...THEN SHIFT TO
S-SW FRI NIGHT. EXPECT WINDS AND SEAS BELOW SMALL CRAFT CRITERIA.

SATURDAY-SUNDAY...SW WINDS MAY BRIEFLY GUST TO 25 KT DURING SAT ON 
THE EASTERN WATERS...OTHERWISE EXPECT GUSTS UP TO 20 KT SEAS BUILD 
AGAIN TO AROUND 5 FT ACROSS THE OUTER WATERS...WHICH WILL SLOWLY 
SUBSIDE LATE SUN OR SUN NIGHT.

&&

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

&&

$$
SYNOPSIS...RLG/EVT
NEAR TERM...DUNTEN/RLG
SHORT TERM...RLG
LONG TERM...EVT
AVIATION...RLG/EVT
MARINE...RLG/EVT

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