091
FXUS61 KBOX 161406
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1006 AM EDT WED OCT 16 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN MOSTLY IN CONTROL TODAY...PROVIDING DRY
WEATHER FOR MUCH OF THE INTERIOR...BUT A FEW SHOWERS ARE POSSIBLE
ALONG THE EAST COAST. ANOTHER ROUND OF SHOWERS ARE POSSIBLE WITH A
COLD FRONT TONIGHT INTO EARLY THURSDAY...WITH A CHANCE FOR MORE
WIDESPREAD SHOWERS LATE THURSDAY NIGHT INTO FRIDAY. DRY WEATHER
THEN RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...MADE MINOR EDITS TO TEMPERATURE AND DEWPOINT GRIDS
TO ACCOUNT FOR THE LATEST TRENDS. ALSO TRIMMED POPS BACK A BIT
ACROSS EASTERN NEW ENGLAND. FOG HAS DISSIPATED ACROSS MUCH OF THE
REGION...WITH THE EXCEPTION BEING ACROSS PARTS OF EASTERN
MASSACHUSETTS...PARTICULARLY THE CAPE AND ISLANDS WHERE SOME
PATCHY FOG LINGERS.
PREVIOUS DISCUSSION...
A MUCH CLOUDIER START TO THE MORNING THIS MORNING AS HIGH CI
CONTINUES TO SPILL OVER FROM THE W AHEAD OF A SHORTWAVE...AND SOME
LOWER CLOUDS BUILD N IN ADVANCE OF A WEAK INVERTED TROUGH OF LOW
PRES TO THE S. THEREFORE...A METEOROLOGICAL SQUEEZE PLAY IS
EXPECTED TODAY AS A RIDGE OF HIGH PRES WILL GRADUALLY BE FORCED
OUT BY THE TWO AFOREMENTIONED TROUGHS. THE LATTER
TROUGH...ASSOCIATED WITH A DYING COASTAL LOW...LOOKS TO CARRY
ENOUGH MOISTURE /PWATS ABOUT 1.0 INCHES/ AND CONDITIONAL
INSTABILITY /K VALUES AROUND 30/ TO INITIATE SOME -SHRA ACTIVITY
WHICH IS BEGINNING TO SHOW UP ON LATEST RAD IMG S AND E OF ACK.
THIS WILL BE THE MAIN CONCERN TODAY. WITH THE HIGH PRES SLOWLY
SLIPPING TO THE N AND E...THE DRY COLUMN AND SUBSIDENCE WILL
LIKELY BE DIFFICULT TO OVERCOME IN THE INTERIOR...SO WILL FOCUS
POPS E OF A LINE FROM EWB-BOS...BUT IT IS LIKELY ACK AND THE OUTER
ARM OF THE CAPE WILL BE EFFECTED MOST BY THE -SHRA THROUGH THE
MORNING. CAPPED POPS AT CHANCE...AS BEST FORCING WILL REMAIN
OFFSHORE...BUT ITS NOT OUT OF THE QUESTION PORTIONS OF THE S SHORE
MAY SEE A FEW DROPS TODAY AS WELL. THE SECOND TROF MOVING IN FROM
THE W...WILL BEGIN TO SHUNT THE COASTAL TROF OFFSHORE THIS
AFTERNOON AND EVENING...SO EXPECT A GRADUAL END TO THE -SHRA
CHANCES THROUGH THE LATTER HALF OF THE DAY.
GIVEN A FAIR AMOUNT OF CLOUDS ARE EXPECTED TODAY /MID AND HIGH
CLOUDS BUILDING OVER A LOWER SC DECK ASSOCIATED WITH THE TROUGH IN
THE E/ TEMPERATURES WILL REMAIN SIMILAR TO YESTERDAYS DESPITE A
SLIGHT INCREASE IN MID LVL TEMPS. THEREFORE...EXPECTING HIGHS IN
THE MID TO UPPER 60S...WITH AN ISOLATED LOW 70S POSSIBLE IN THE
SW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...
SECOND SHORTWAVE AND ATTENDANT LOW PRES WILL BE GRADUALLY
SHIFTING TO THE NE FROM THE GREAT LAKES...SLIDING NORTHWEST OF THE
AREA DURING THE OVERNIGHT HOURS. ATTENDANT COLD FRONT WILL BE
MOVING E ARRIVING IN THE W AROUND 06Z...THEN SHIFTING E WITH TIME.
BULK OF THE BEST FORCING /A 40 KT LLJ AND STRONGEST BAROCLINIC
ZONE/ ARE EXPECTED TO MOVE TO THE NW WITH THE PARENT LOW...SO THIS
FRONT WILL BE WASHING OUT RAPIDLY WITH TIME. GUIDANCE SOUNDINGS
CONTINUE TO SUPPORT MAINLY DRY COLUMN THROUGH THE AREA SO EXPECT
THAT BEST CHANCE FOR PRECIP WILL BE N AND W OF A HFD-ORH-EEN. WILL
AT LEAST SUGGEST SLIGHT CHANCE POPS E GIVEN LOW LVL MOISTURE...BUT
SUSPECT THAT MANY LOCATIONS S AND E OF THE LINE WILL REMAIN DRY
OVERNIGHT AND INTO EARLY THU. A FAIR AMOUNT OF CLOUD COVER AND
INCREASING DWPTS /TO THE LOW 50S/ WILL LEAD TO A MILD NIGHT...MINS
ARE EXPECTED TO HOLD IN THE LOW TO MID 50S.
THU...
COLD FRONT WILL BE SLIDING THROUGH THE ERN HALF OF THE REGION
DURING THE MORNING AND SHOULD BE OFFSHORE BY MID TO LATE
AFTERNOON. EXPECT EARLY MORNING CLOUD COVER TO GRADUALLY ERODE AS
DRY W FLOW DEVELOPS AND ENHANCES THE DRY COLUMN ALREADY IN PLACE
ACROSS THE REGION FROM ABOUT H9-H5...WHICH WILL MITIGATE PRECIP
CHANCES AS WELL. THEREFORE...SOME SUNSHINE IS EXPECTED ACROSS THE
REGION PARTICULARLY IN THE AFTERNOON. GIVEN LITTLE CHANGE IN THE
AIRMASS BEHIND THE FRONT...A DOWNSLOPING COMPONENT TO THE WIND AND
H92 TEMPS AROUND +13C...THIS SUNSHINE SHOULD ALLOW HIGHS TO
REBOUND INTO THE 70S AT MORE LOCATIONS THAN PREVIOUS DAYS. MAINLY
DRY FOR THE DAY GIVEN THE WEAKENING FRONT AND SECONDARY SHORTWAVE
ENERGY WILL TAKE UNTIL THE OVERNIGHT HOURS TO ARRIVE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
BIG PICTURE... UPPER RIDGES OVER THE PACIFIC COAST AND FLORIDA WITH
A DEEP UPPER TROUGH EXTENDING FROM THE CANADIAN ARCTIC TO THE GREAT
PLAINS. ONE SHORTWAVE EXITING THE TROUGH MOVES UP THE ST LAWRENCE
VALLEY THURSDAY NIGHT AND THROUGH THE MARITIMES ON FRIDAY. A SECOND
SHORTWAVE DIVES SOUTH FROM THE ARCTIC...SWINGS THROUGH THE PLAINS ON
FRIDAY...AND THEN EJECTS THROUGH NEW ENGLAND ON SUNDAY. THE UPPER
TROUGH BROADENS OVER THE NORTHEAST USA OVER THE WEEKEND AND EARLY
NEXT WEEK.
GOOD MODEL AGREEMENT
THE DAILIES...
THURSDAY NIGHT-FRIDAY... SHORTWAVE OVER THE GREAT LAKES THURSDAY
EVENING MOVES NORTHEAST OVERNIGHT AND FRIDAY. A 25-30 KNOT LOW
LEVEL JET MOVES UP THE COAST OVER SOUTHERN NEW ENGLAND AS DOES THE
SUPPORTING UPPER JET. THIS MEANS GOOD JET DYNAMICS FOR LIFT...AND
CROSS SECTIONS SHOW A DEEP LAYER OF MOISTURE TO TAP. PRECIP WATER
VALUES ARE FORECAST AT 1-1.5 INCHES. THIS IS SUFFICIENT SUPPORT FOR
LIKELY POPS WITH HIGHEST VALUES IN OUR NORTHERN SECTIONS...THEY ARE
CLOSER TO THE SHORTWAVE AND MORE CLEARLY IN THE FAVORABLE LEFT EXIT
REGION OF THE UPPER JET. MODEL TIMING OF THE DEPARTURE OF THE
SURFACE SYSTEM IS SIMILAR AND PLACES IT IN OUR VICINITY FIRST THING
FRIDAY MORNING BUT MOVING TO OUR EAST BY MIDDAY. SO THIS MEANS VERY
LOW OR NIL POPS THURSDAY EVENING TRENDING HIGHER OVERNIGHT AND THEN
DIMINISHING DURING FRIDAY MORNING. CLEARING/SUNSHINE/MIXING IN THE
AFTERNOON WILL COMBINE WITH THE PRESSURE CHANGE TO BRING BREEZY
CONDITIONS. BUT NORTHWEST WINDS SHOULD ONLY GUST AROUND 20 KNOTS IN
THE AFTERNOON.
SATURDAY THROUGH TUESDAY... THIS SHOULD BE A GENERALLY DRY PERIOD AS
HIGH PRESSURE BUILDS OVER THE REGION. THE SUNDAY SHORTWAVE MAY PUSH
A WEAK FRONT THROUGH BUT LITTLE OR NO PCPN IS EXPECTED. DAYTIME
HIGHS EXPECTED IN THE MID 50S TO MID 60S/NIGHTTIME LOWS IN THE MID
30S TO MID 40S.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY/...MODERATE CONFIDENCE.
PATCHES OF FOG...AND SOME LOCALLY DENSE FOG...WILL DIMINISH
THROUGH THE MORNING. MEANWHILE MIXED IFR/LIFR CIGS MOVED UP ACROSS
THE ISLANDS AND PARTS OF EASTERN CAPE COD. THE LOW CIGS WILL
LINGER THROUGH THE MORNING THEN DIMINISH. THE LOW CLOUDS AND SOME
LIGHT SHOWERS ARE DUE TO LOW PRESSURE PASSING OFFSHORE. THIS
FEATURE SHOULD MOVE OFF LATER TODAY. CIGS/VSBYS WILL TREND TO VFR
WHERE THEY ARE NOT THERE ALREADY.
TONIGHT INTO THU...A WEAK COLD FRONT WILL BRING SOME -SHRA
ESPECIALLY N AND W OF AN IJD-LWM LINE WITH OCCASIONAL MVFR
CIGS/VSBYS AS WELL. ANOTHER IMPROVEMENT IS EXPECTED DURING THE DAY
THU.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. PERIOD OF MVFR CIGS
EXPECTED THIS MORNING...BUT SHOULD IMPROVE TO VFR AGAIN THIS
AFTERNOON.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT-FRIDAY MORNING... CIGS/VSBYS WILL LOWER TO MVFR IN
SHOWERS AROUND AND AFTER MIDNIGHT. CONDITIONS MAY BRIEFLY REACH IFR
IN SHOWERS AND FOG LATE AT NIGHT INTO THE FRIDAY MORNING RUSH
HOUR...BUT WITH IMPROVING CONDITIONS BY MIDDAY.
FRIDAY AFTERNOON THROUGH SUNDAY... VFR. NORTHWEST WINDS GUSTING TO
20 KNOTS FRIDAY AFTERNOON AND DIMINISHING IN THE EVENING.
&&
.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.
WINDS AND SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH THURSDAY. A FEW FIVE FOOT SEAS ARE POSSIBLE ALONG THE
EXTREME OUTER EDGE OF THE SRN OCEAN WATERS THIS MORNING...BUT
THESE WILL GRADUALLY DIMINISH THROUGH THE DAY. SOME SHOWERS...AND
POSSIBLY EVEN AN ISOLATED THUNDERSTORM ARE POSSIBLE THROUGH THIS
AFTERNOON ON THE EASTERN WATERS. PATCHY FOG MAY LIMIT VSBYS LATE
TONIGHT.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT-FRIDAY...SEAS BUILD TO 5-6 FEET ON THE OUTER WATERS.
NORTHWEST WINDS ON FRIDAY WILL GUST TO AROUND 20 KNOTS ON ALL
WATERS. A FEW GUSTS TO 25 KNOTS ARE POSSIBLE. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR SOME OF THE WATERS DURING THIS
PERIOD.
SATURDAY-SUNDAY...QUIET WEATHER SATURDAY. WEST TO SOUTHWEST WINDS
MAY GUST 20-25 KNOTS AHEAD OF A WEAK COLD FRONT SUNDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/DOODY
NEAR TERM...WTB/DOODY/RLG
SHORT TERM...DOODY
LONG TERM...WTB
AVIATION...WTB/DOODY
MARINE...WTB/DOODY