Area Forecast Discussion
Issued by NWS Boston, MA

Home | 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 070341
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1141 PM EDT MON JUL 6 2015

.SYNOPSIS...
WARM AND MUGGY CONDITIONS ARE ANTICIPATED TOMORROW AND WEDNESDAY
AS A SERIES OF FRONTS BRINGS SCATTERED SHOWERS AND THUNDERSTORMS.
THE LAST FRONTAL BOUNDARY WILL STALL IN PROXIMITY OF THE
S-SHORELINE OF NEW ENGLAND FOR THE REMAINDER OF THE WEEK BECOMING
A FOCUS FOR ADDITIONAL WET-WEATHER. ALL OF THIS LOOKS TO CLEAR OUT
BY THE WEEKEND ALLOWING FOR DRY AND SEASONABLE CONDITIONS. WILL
POTENTIALLY SEE WET WEATHER RETURN ALONG WITH A WARM AND MUGGY
PATTERN INTO EARLY NEXT WEEK.

&&

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

11 PM UPDATE...

DEWPTS HAVE RISEN QUICKLY SINCE 00Z ACROSS THE REGION...MAINLY IN
THE LOWER-MID 60S ACROSS THE REGION. WITH THE HIGHER DEWPTS
ESPECIALLY ACROSS S COASTAL AREAS...EXPECT TEMPS TO LEVEL OFF A
BIT MILDER THAN PREVIOUSLY FORECAST...WHICH HAVE BEEN UPDATED.

ALSO NOTED THAT LOW CLOUDS HAVE WORKED INTO NYC AREA AND ACROSS
LONG ISLAND WITH THE LIGHT S-SE WINDS THERE AT 03Z. WITH
LIGHT/VRBL OR CALM WINDS ACROSS MOST OF THE REGION...SHOULD KEEP
LOW CLOUDS AND PATCHY FOG FROM DEVELOPING UNTIL AFTER 06Z ALONG
THE S COAST WITH THE ONSHORE WINDS AND TEMP/DEWPT SPREADS LOWER.
PATCHY FOG WILL ALSO DEVELOP FURTHER INLAND WITH THE HIGHER
DEWPTS...BUT WILL PROBABLY HOLD OFF UNTIL AROUND SUNRISE FOR A FEW
HOURS ESPECIALLY WHERE WINDS BECOME CALM.

HAVE UPDATED REMAINING NEAR TERM FORECAST TO BRING CONDITIONS
CURRENT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY INTO TUESDAY NIGHT...

WARM FRONT WILL LIFT NORTHWARD TOMORROW PUTTING SOUTHERN NEW ENGLAND
INTO A THE WARM/MOIST AIRMASS. A WEAK SHORTWAVE ALOFT WILL TRIGGER A
FEW SCT SHOWERS WILL DEVELOP ACROSS THE REGION AFTER 11 AM LASTING
INTO THE EVENING HOURS. MU CAPE VALUES COULD INCREASE TO 1500 J/KG
AND WITH 20-30 KT SHEAR COULD SEE SOME STRONG STORMS. HAVE A VERY
LOW CONFIDENCE ON IF ANY WOULD BE COME SEVER. LIMITING FACTOR IS THE
LAPSE RATES AND THE CLOUD COVER...WHICH WOULD LIMIT THE AMOUNT OF
INSTABILITY THAT COULD DEVELOP. YET PWAT VALUES ARE OVER 1.5 INCHES
AND WITH WARM RAIN CORE PROCESSES...COULD SEE SOME HEAVY DOWNPOURS
WITH PERHAPS URBAN/POOR DRAINAGE FLOODING.

AS 850 MB TEMPS WARM TO 16C AND WITH DEWPOINTS REACHING CLOSE TO
70F...ANTICIPATE A WARM/MUGGY DAY.

CONVECTION WILL BEGIN TO WIND DOWN BY THE EVENING HOURS AS HEATING
IS LOST AND WE ARE ON THE BACKSIDE OF THE SHORTWAVE. SOUTHWESTERLY
FLOW AHEAD OF AN APPROACHING COLD FRONT WILL KEEP THE REGION IN
WARM/MOIST FLOW. THIS WILL ALLOW FOR FOG TO DEVELOP ESP ALONG THE
SOUTH COAST. OVERNIGHT TEMPS WILL WILL BE MILD WITH SEVERAL PLACES
ONLY DROPPING INTO THE LOW 70S.

&&

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

 - SCATTERED SHOWERS / THUNDERSTORMS FOR WEDNESDAY
 - CONTINUED PERIODS OF WET WEATHER INTO THE END OF THE WEEK
 - LOOKING DRY AND SEASONABLE FOR THE WEEKEND
 - A POSSIBLE RETURN OF A WARM-WET-MUGGY PATTERN NEXT WEEK

*/ DISCUSSION...

WEDNESDAY:

SKEPTICAL ON COLD FRONT TIMING. FEEL IT WILL SLOW AS IT SWEEPS S/E
WITH ATTENDANT MID-LEVEL ENERGY AWAY FROM FASTER MID- TO UPPER-LEVEL
FLOW...RUNNING UP AGAINST THE OFFSHORE BERMUDA HIGH. EXPECTATION
THAT THE FRONT WILL ENTER S NEW ENGLAND AROUND THE 11A-2P TIMEFRAME
SLOWING UP TOWARDS S/E NEW ENGLAND AROUND 2P-5P. HIGHER CONFIDENCE
WITH SREF-PROBS OVER DETERMINISTIC SOLUTIONS.

THUS CONSIDERING A HIGH THETA-E / INSTABILITY ENVIRONMENT ALONG AND
AHEAD OF THE COLD FRONT WITHIN A WEAK-SHEAR ENVIRONMENT WITH VECTOR-
ORIENTATION NOT OVERTLY PERPENDICULAR TO THE COLD FRONT. DO EXPECT
SCATTERED ACTIVITY WITH PLAUSIBLE LINE-ECHO WAVE PATTERNS ESPECIALLY
FOR SE NEW ENGLAND WHERE THERE IS A GREATER RESIDENCY TIME FOR THE
ENVIRONMENT TO DESTABILIZE AND THERE IS ENOUGH SHEAR. THINK FORCING
IS NOT IN QUESTION ALONG THE FRONT AS LOW- TO MID-LEVEL FLOW IS ALSO
PERPENDICULAR TO THE FRONT. ALSO AM NOT THINKING ANYTHING SEVERE.
MAYBE STRONG. LAPSE RATES ARE FAIRLY POOR ALOFT BASED ON A CONSENSUS
OF FORECAST GUIDANCE. MAINLY FOCUSED ON GREATER AREAL COVERAGE OF
ACTIVITY MORE SO THAN THE NAM/GFS DETERMINISTIC SUGGEST. AND WITH
PWATS ADVERTISED IN EXCESS OF 2-INCHES...THE BIGGEST THREAT IS HEAVY
RAIN. WILL LEAN WITH LIKELY POPS ESPECIALLY FOR S/SE-PORTIONS OF S
NEW ENGLAND.

REST OF THE WEEK:

CONTINUING WITH SREF-PROBS BELIEVE THE FRONTAL BOUNDARY WILL STALL
SOMEWHERE IN PROXIMITY TO THE S-COAST OF NEW ENGLAND BECOMING THE
FOCUS FOR ADDITIONAL WET-WEATHER AS MID-LEVEL IMPULSES TRAVEL
THROUGH THE QUASI-ZONAL FLOW ALOFT THAT IS PARALLEL TO THE FRONT.
LIKELY TO SEE THE FRONT WOBBLE WITH LATER FORECASTS. THOUGH OVERALL
DO THINK INSTABILITY HOLDS MAINLY S WITH ONCE AGAIN THE MAIN THREAT
BEING HEAVY RAIN. NEVERTHELESS CAN NOT RULE OUT A RUMBLE OF THUNDER.
A CONSENSUS OF GUIDANCE HAS THE FLOW BEING OVERALL PROGRESSIVE
DESPITE TRAINING OF DISTURBANCES. WAVES LOOK TO BE SPACED OUT ENOUGH
TO YIELD A LOW CONFIDENCE CONCERNING ANY FLOODING. JUST LOOKING LIKE
A WET PATTERN WITH PERHAPS WARM-MUGGY CONDITIONS DEPENDING ON THE
ORIENTATION AND PROXIMITY OF THE STALLED FRONTAL BOUNDARY.

WEEKEND:

BOTH DETERMINISTIC / ENSEMBLE GUIDANCE IN GOOD AGREEMENT OF THE
TROUGH PATTERN LIFTING E. WITHIN THE W-PERIPHERY ALONG WITH RISING
HEIGHTS EXPECT A SURFACE REFLECTION OF HIGH PRESSURE. DEEP-LAYER
NORTHERLY WINDS SHOULD USHER DRIER AND MORE SEASONABLE CONDITIONS
SOUTHWARD...SO LOOKS LIKE A BREAK FROM THE WARM-MUGGY PATTERN.

EARLY NEXT WEEK:

APPEARS THE TROUGH PATTERN RETURNS BASED ON ENSEMBLE MEANS. A LIKELY
RETURN TO WARM-MUGGY CONDITIONS AND AN ACTIVE WEATHER PATTERN.

&&

.AVIATION /03Z 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 NIGHT/...

OVERNIGHT...MODERATE CONFIDENCE.

VFR. MAY SEE MVFR-IFR CIGS AND/OR VSBYS ALONG S COASTAL AROUND OR
AFTER 06Z. PATCHY FOG WITH MVFR CIGS/VSBYS MAY DEVELOP AROUND
07Z- 09Z FURTHER INLAND...UP TO MID CT VALLEY AND ACROSS S CENTRAL
MA/RI/SE MA. LIGHT S-SE WINDS.

TUESDAY...HIGH CONFIDENCE.

MVFR-IFR CIGS AND ANY FOG LIFT TO HIGH-END MVFR / LOW-END VFR.
-SHRA/-TSRA DEVELOPING OVER W/SW-TERMINALS BY AFTERNOON. SEA-
BREEZES DURING THE MORNING WILL ERODE WITH INCREASING S-WINDS
GUSTING UP TO 25 KTS POSSIBLE ALONG THE S-COAST.

TUESDAY NIGHT...MODERATE CONFIDENCE.

CONDITIONS POSSIBLY DROPPING BACK TO MVFR-IFR ALONG WITH THE
POTENTIAL FOR PATCHY FOG.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA-BREEZE DURING THE
MORNING WILL ERODE BY AFTERNOON TUESDAY PER INCREASING S-WINDS.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF. PATCHY FOG IS POSSIBLE
TONIGHT. LOW RISK OF A -TSRA TOMORROW AFTERNOON.

OUTLOOK /WEDNESDAY THROUGH SATURDAY/...

WEDNESDAY...MODERATE CONFIDENCE. MAINLY VFR. SCT SHRA/TSRA ESP S
/SE-NEW ENGLAND. TEMPO MVFR-IFR WITH ANY WX. COLD FRONT PUSHES
OFFSHORE LATE. SW-WINDS SHIFT NORTHERLY.

THURSDAY AND FRIDAY...LOW CONFIDENCE. LOW-END VFR / MVFR. FRONT
STALLS IN PROXIMITY TO S-SHORE OF NEW ENGLAND. FOCUS OF ADDITIONAL
-RA / RA. VARIABLE WINDS.

SATURDAY...MODERATE CONFIDENCE. VFR. N/NW-WINDS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT-TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE.

11 PM UPDATE...

WINDS AND SEAS BELOW SMALL CRAFT CRITERIA OVERNIGHT. PATCHY FOG
POSSIBLE ACROSS THE SOUTHERN WATERS WITH LOCALLY REDUCED VSBYS.

SEAS WILL BEGIN TO BUILD TUESDAY AS A WARM FRONT MOVES N. COULD
SEE SOME LOW END SCA DURING THE AFTERNOON WITH SOUTHERLY WIND
GUSTS NEAR 25 KTS AND SEAS 4-5 FT. ALTHOUGH MARGINAL...FELT IT
WAS BEST DUE TO ALL OF THE RECREATIONAL BOATERS ACROSS THE WATERS
THIS WEEK.

AFTER SUNSET...S WINDS WILL DIE DOWN BUT COULD SEE A CHOP ALONG
THE WATERS OVERNIGHT. PATCHY DENSE FOG COULD ALSO REDEVELOP OVER
THE WATERS.

OUTLOOK /WEDNESDAY THROUGH SATURDAY/...

WEDNESDAY...MODERATE CONFIDENCE.

SCATTERED SHOWERS AND THUNDERSTORMS FOR THE WATERS INTO THE
AFTERNOON HOURS AND CONTINUING INTO THE EVENING. BREEZY SW-WINDS
AHEAD OF THE FRONT BECOMING VARIABLE AS THE FRONT STALLS IN
PROXIMITY TO THE S-COAST. WAVES HOLDING BELOW 5-FEET. PATCHY DENSE
FOG POSSIBLE AT TIMES.

THURSDAY AND FRIDAY...LOW CONFIDENCE.

FRONT STALLS W TO E ACROSS THE S-WATERS. PERIODS OF WET WEATHER.
VARIABLE WINDS THROUGHOUT KEEPING WAVES BELOW 5-FEET. PATCHY DENSE
FOG POSSIBLE AT TIMES.

SATURDAY...MODERATE CONFIDENCE.

HIGH PRESSURE BUILDING INTO THE WATERS. N/NW-WINDS PERHAPS BLUSTERY
AT TIMES. WILL HOLD WAVES BELOW 5-FEET.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM TO 9 PM EDT TUESDAY FOR
     ANZ230>237-251.

&&

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


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