Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 051909 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 309 PM EDT SUN JUL 5 2015 .SYNOPSIS...
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DRY AND ABOVE-SEASONABLE CONDITIONS PREVAIL BENEATH HIGH PRESSURE INTO TUESDAY MORNING. A SERIES OF FRONTS WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY. DRY WEATHER SHOULD PREVAIL INTO NEXT WEEKEND...ALTHOUGH A STALLED FRONT SOUTH OF NEW ENGLAND MAY TRIGGER A FEW SHOWERS FROM TIME TO TIME.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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INTO THIS EVENING... QUIET WEATHER WITH LIGHT WINDS. SEA-BREEZES PUSHING ONSHORE WILL BEGIN TO WASH OUT. HIGHS AROUND THE LOW- TO MID-80S WILL DROP BACK INTO THE UPPER-70S. COOLER ALONG THE SHORES WITH THE ONSHORE FLOW. TONIGHT... NICE. PLEASANT. BENEATH THE RIDGE SURFACE HIGH PRESSURE PREVAILS. MOSTLY CLEAR OVERALL UNDER LIGHT SW-WINDS. ANTICIPATING SOME LEVEL OF RADIATIONAL COOLING AND THUS WILL DROP LOWS SEVERAL DEGREES BELOW MOS-GUIDANCE. LOWS AROUND THE UPPER-50S WITH THE COOLEST SPOTS IN NW MA...WARM ALONG THE COASTS. PATCHY DENSE FOG LIKELY ESPECIALLY WHERE ONSHORE FLOW KEEPS DEWPOINTS ABOVE THE 60-DEGREE MARK. FOCUS ACROSS THE CT-RIVER VALLEY / RI / SW MA. CAN NOT RULE OUT SOME LOW-LYING AREAS IN CENTRAL / E MA AS WELL.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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MONDAY... CONTINUED RIDGING INFLUENCE OF HIGH PRESSURE. WILL SEE THE PUSH OF WARM-MOIST AIR N ALONG ITS W-PERIPHERY INTO S/W-PORTIONS OF NEW ENGLAND...ALONG WITH SOME THIN-HIGH CLOUDS LATE. WITH EFFECTIVE BOUNDARY-LAYER MIXING ABOVE H9 EXPECT HIGHS INTO THE INTO THE MID- TO UPPER-80S OVER ALL INTERIOR LOCALES IMMEDIATELY AWAY FROM THE SHORELINE. CAN NOT RULE OUT A LOCATION OR TWO REACHING 90-DEGREES. WITH FORECAST LIGHT WINDS EXPECT SEA-BREEZES TO PUSH INLAND. MONDAY NIGHT... WITH THE RIDGE SLIPPING FURTHER E ALLOWING RETURN S-FLOW ACROSS MUCH OF NEW ENGLAND UNDERGOING GRADUAL ISENTROPIC ASCENT...EXPECT THE ENCROACHMENT OF THICKER CLOUDS INTO S/W-PORTIONS OF NEW ENGLAND. THOUGH AN INCREASING PRESENCE OF THETA-E FROM THE WOBBLING LOW PRESSURE CENTER ACROSS THE MID-ATLANTIC...FEEL THE PRESENCE OF DRY AIR PER THE INFLUENTIAL RIDGE WILL KEEP LIGHT SHOWERY WEATHER AT A MINIMUM. PREVAILING LIGHT S-WINDS WILL KEEP LOWS SLIGHTLY MILDER AROUND THE LOW-60S. CONTINUING RISING DEWPOINTS. ANOTHER NIGHT OF PATCHY DENSE FOG NOT OUT OF THE QUESTION.
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&& .LONG TERM /TUESDAY THROUGH SUNDAY/...
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HIGHLIGHTS... * SHOWERS/STORMS TUE AND WED * HIGH UNCERTAINTY LATER IN WEEK BUT MAINLY DRY DETAILS... UNCERTAINTY INCREASES AS WE HEAD THROUGH WEEK DUE TO TRANSITION IN LARGER SCALE PATTERN. INITIALLY HIGH AMPLITUDE PATTERN WITH RIDGING OVER EASTERN STATES GIVES WAY TO MORE ZONAL FLOW ACROSS NORTHERN TIER OF STATES AS RIDGE BECOMES SUPPRESSED AND WE FEEL MORE OF EFFECTS OF CLOSED LOW OVER CENTRAL CANADA. HOW QUICKLY RIDGE SHIFTS TO OUR S AND HOW MUCH WE BECOME INFLUENCED BY NORTHERN STREAM REMAINS TO BE SEEN...BUT MAKES DIFFERENCE BETWEEN DRY AND SEASONABLE WEATHER LATER THIS WEEK OR MORE IN WAY OF COOLER/SHOWERY CONDITIONS. FORECAST IS LARGELY WEIGHTED ON BLEND OF AVAILABLE GUIDANCE AND ENSEMBLES TO HELP IRON OUT UNCERTAINTY...ESPECIALLY BEYOND DAY 3. TUE AND WED...MODERATE CONFIDENCE. WARM FRONT LIFTS THROUGH REGION TUE. AFTER POSSIBILITY OF FEW MORNING SHOWERS PRIMARILY ACROSS INTERIOR...AIRMASS SHOULD BE ABLE TO DESTABILIZE WITH SB CAPES APPROACHING 1500 J/KG IN AFTERNOON IN WESTERN NEW ENGLAND. HOWEVER 0-6KM SHEAR AND MID LEVEL LAPSE RATES ARE RATHER WEAK...IN ADDITION TO LACK OF LARGE SCALE FORCING SO OVERALL SEVERE THREAT IS LOW. NONETHELESS WE SHOULD SEE SCATTERED SHOWERS/STORMS FOCUSED NEAR BERKSHIRES TUE AFTERNOON. POTENTIAL FOR LOCALIZED FLOODING GIVEN PRECIPITABLE WATER VALUES AROUND +2 SD. ANOTHER ROUND OF SHOWERS/STORMS EXPECTED WED AS COLD FRONT CROSSES SOUTHERN NEW ENGLAND. CONDITIONS LOOK A LITTLE MORE FAVORABLE FOR STRONG OR ISOLATED SEVERE STORMS IN AFTERNOON AND EVENING BUT AS IS TYPICALLY CASE THERE ARE MIXED SIGNALS. SB CAPES SHOULD BE NEAR 1500 J/KG BUT 0-6KM SHEAR 20-25KT AND WEAK MID LEVEL LAPSE RATES ARGUE AGAINST A MORE WIDESPREAD SEVERE THREAT. ONE AREA TO KEEP AN EYE ON IS ACTUALLY ACROSS E MA LATER IN DAY WHICH SHOULD BE ON EDGE OF AN AREA OF HIGHER 0-6KM SHEAR LOCATED OFFSHORE. THU THROUGH SUN...LOW CONFIDENCE. DEPENDING ON HOW LARGER SCALE PATTERN EVOLVES...TO EITHER MORE OF ZONAL FLOW OR WEAK RIDGING AHEAD OF CANADIAN CLOSED LOW...WE COULD END UP WITH STRETCH OF DRY WEATHER OR PERIODS OF SHOWERS/STORMS. FOR NOW WE ARE LEANING TOWARD DRIER SOLUTION AND WILL KEEP POPS LOW. DOES LOOK LIKE TEMPERATURES WILL BE AT OR PERHAPS SLIGHTLY BELOW AVERAGE FOR MID JULY.
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&& .AVIATION /19Z SUNDAY THROUGH FRIDAY/...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE. MAINLY VFR. PATCHY IFR FOG POSSIBLE OVERNIGHT. FOCUS CT-RIVER VALLEY / LOW-LYING LOCALES OF MA / RI. LIGHT WINDS TURNING S INTO MONDAY AT OR BELOW 10 KTS. SEA-BREEZES ALONG THE SHORES AROUND 16Z. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA-BREEZE PRESENTLY WILL CONTINUE TO WAFFLE OVER THE TERMINAL AS WE GO INTO EVENING. WINDS SHOULD REMAIN AT OR BELOW 6 KTS. ANOTHER SEA-BREEZE EXPECTED AROUND 16Z MONDAY. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. PATCHY FOG POSSIBLE AROUND 8-11Z. OUTLOOK /TUESDAY THROUGH FRIDAY/... TUE AND WED...MODERATE CONFIDENCE. MVFR/IFR IN SCT SHOWERS/TSTMS. PATCHY FOG AT NIGHT. THU AND FRI...LOW CONFIDENCE. VFR.
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&& .MARINE...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE. QUIET BOATING WEATHER. SEAS CONTINUE TO DIMINISH BENEATH HIGH PRESSURE. WINDS TURN S THROUGH MONDAY INTO MONDAY NIGHT WITH ANY GUSTS REMAINING BELOW 20 KTS. PATCHY DENSE FOG POSSIBLE DURING THE OVERNIGHT PERIODS. OUTLOOK /TUESDAY THROUGH FRIDAY/... MODERATE CONFIDENCE. MAINLY LIGHT WINDS AND FLAT SEAS AS A SERIES OF WEAK FRONTS CROSS WATERS...BUT COULD SEE 4-5 FT SEAS ON SOUTHERN WATERS S OF ISLANDS BY WED OR THU DUE TO BUILDING SWELL. MAIN CONCERN IS FOR SCATTERED SHOWERS/STORMS TUE AND WED...AS WELL AS PATCHY LATE NIGHT/EARLY MORNING FOG.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...SIPPRELL/JWD NEAR TERM...SIPPRELL SHORT TERM...SIPPRELL LONG TERM...JWD AVIATION...SIPPRELL/JWD MARINE...SIPPRELL/JWD

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