Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBOX 201804 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 204 PM EDT WED AUG 20 2014 .SYNOPSIS... MAINLY DRY WEATHER...EXCEPT MAYBE A SHOWER IN THE WEST...WITH TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL EXPECTED THROUGH THE WEEKEND. PATTERN STARTS TO BECOME A BIT MORE UNSETTLED EARLY NEXT WEEK WITH AN APPROACHING FRONT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
2 PM UPDATE... DRY AND QUIET WEATHER. RIDGE OF HIGH PRESSURE FROM THE E/NE RESULTING IN LIGHT AND VARIABLE WINDS. SEA-BREEZES PROGRESSING TOWARDS INTERIOR NEW ENGLAND AS A RESULT OF BOTH THE PRESSURE AND THERMAL GRADIENT. FEW TO SCATTERED CLOUDS ACROSS THE REGION... BROKEN MORESO OVER THE BERKSHIRES SUBSEQUENT OF HIGHER THETA-E AIR WRAPPING AHEAD OF THE APPROACHING CLOSED LOW OUT OF THE GREAT LAKES REGION AND CONVERGING ALONG THE HIGHER TERRAIN. WILL KEEP WITH A DRY FORECAST WITH A MIX OF SUN AND CLOUDS. HIGHS INTO THE LOW-80S ACROSS THE INTERIOR WITH A FEW LOCALES MAXING OUT IN THE MID-80S...COOLER CONDITIONS ALONG THE SHORELINE WITH SEA- BREEZES.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... TONIGHT... THE APPROACHING WARM FRONT AND GRADUALLY OPENING UPPER LVL CUTOFF...COMBINED WITH GRADUAL MOISTURE LOADING OF THE COLUMN IS LIKELY TO LEAD TO MORE CLOUD COVER ACROSS THE REGION THAN PREVIOUS NIGHTS. NOT OUT OF THE QUESTION A SHOWER IS ABLE TO SLIDE ACROSS THE W...BUT BOTH JET AND VORTICITY RELATED DYNAMICS ARE QUITE WEAK AND OVERALL COLUMN MOISTURE REMAINS FAIRLY LOW UNTIL THE EARLY MORNING HOURS. THEREFORE...WILL MAINTAIN A MOSTLY DRY FORECAST EXCEPT THE EXTREME WRN FRINGES OF THE BOX CWA THROUGH THE OVERNIGHT HOURS. REGARDING TEMPERATURES...GIVEN THE INCREASED MOISTURE /CLOUD COVER/ AND WARMER EVENING TEMPERATURES EXPECT THAT OVERNIGHT LOWS WILL BE WARMER THAN PREVIOUS NIGHTS IN SPITE OF THE NEAR CALM FLOW ONCE AGAIN. MORE WIDESPREAD MID 50S WITH EVEN SOME NORMAL HEAT ISLANDS HOLDING IN THE LOW-MID 60S ARE EXPECTED. THURSDAY... INVERTED RIDGING REMAINS IN PLACE...AND MAINLY E-SE FLOW EXPECTED ACROSS THE REGION. THE MARINE INFLUENCE IS LIKELY TO STAVE OFF APPROACHING WARM FRONT AS IT/S ATTENDANT UPPER LVL CUTOFF DIMINISHES TO AN OPEN WAVE WITH CUTOFF HIGH PRES TO THE N. UPPER LVL AND LOW LVL JETS ARE WEAK AND WITH OVERALL VORTICITY DECREASING...THEREFORE DYNAMIC FORCING IS RELATIVELY WEAK EVEN AS OVERALL COLUMN MOISTURE INCREASES THROUGH THE DAY /PWATS APPROACH 1.75 INCHES/. ALSO...WITH MARINE FLOW AND WARM FRONT TRAPPED TO THE W...IT/S UNLIKELY THAT THERE WILL BE MUCH DESTABILIZATION THROUGH THE DAY. GIVEN ALL OF THIS...THE THREAT FOR SHOWERY ACTIVITY REMAINS FAIRLY LOW. WILL FOCUS ONLY LOW CHANCE POPS W OF THE CT VALLEY...WITH SLIGHT CHANCE POPS INTO THE WORCESTER HILLS. CONVECTIVE ACTIVITY SHOULD DIVE TO THE SW OF THE REGION WHERE INSTABILITY AXIS RESIDES. HAVE KEPT THUNDER OUT OF THE FORECAST WITH THIS UPDATE DUE TO THE MARINE FLOW AND MODEST LAPSE RATES. THE ADDITIONAL CLOUD COVER AND MARINE FLOW ARE ALSO LIKELY TO KEEP HIGH TEMPS COOLER THAN NORMAL /MAINLY MID 70S/ DURING THE DAY THU. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * QUIET WEATHER EXPECTED THROUGH MUCH OF THE LONG TERM * UNCERTAINTY INCREASES EARLY NEXT WEEK WITH AN APPROACHING FRONT RATHER UNIQUE AND STABLE UPPER LEVEL PATTERN WILL SLOWLY BREAK DOWN LATE THIS WEEK INTO THIS WEEKEND. 20/00Z GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH THIS WEEKEND...THEN MORE DIFFERENCES APPEAR EARLY NEXT WEEK. WILL CONTINUE TO FAVOR A CONSENSUS BLEND TO SMOOTH OVER THE MORE MINOR DIFFERENCES. HIGH PRESSURE IN QUEBEC WILL KEEP THINGS RELATIVELY DRY ACROSS MOST OF SOUTHERN NEW ENGLAND THROUGH THIS WEEKEND. THERE IS POTENTIAL FOR A FEW SHOWERS ACROSS THE WESTERN HALF OF SOUTHERN NEW ENGLAND THURSDAY NIGHT IF SOME MOVING PARTS COME TOGETHER. MOISTURE IS THE MAIN LIMITING FACTOR...WITH INSTABILITY A CLOSE SECOND ONCE THE SUN SETS. THIS HIGH PRESSURE WILL SINK SOUTH THROUGH THIS WEEKEND INTO EARLY NEXT WEEK...EVENTUALLY DROPPING SOUTH OF SOUTHERN NEW ENGLAND AND RETURNING US TO A MORE WESTERLY FLOW. A LOW PRESSURE IN ONTARIO MAY EVENTUALLY MOVE EASTWARD INTO QUEBEC...SWINGING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND SOMETIME TUESDAY INTO WEDNESDAY. DEPENDING ON AVAILABLE MOISTURE...THIS FRONT MAY INITIATE A FEW SHOWERS AND THUNDERSTORMS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...THROUGH THURSDAY NIGHT...MODERATE CONFIDENCE. VFR. SEA-BREEZES CONTINUE...BECOMING LIGHT/VRB OVERNIGHT BEFORE PREVAILING E/SE THURSDAY INTO THURSDAY NIGHT. LOW-END VFR CIGS SLOWLY BUILDING E ALONG WITH -RA CHANCES TOWARDS IJD-ORH-AFN. WILL ALSO NEED TO WATCH SE MA FOR POTENTIAL +RA AND MVFR-IFR IMPACTS BEGINNING AFTER MIDNIGHT THURSDAY. CONDITIONS BEGIN TO IMPROVE CLOSER TO FRIDAY MORNING. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. E/SE FLOW PREVAILS. EXPECT CONDITIONS NO LOWER THAN LOW-END VFR CIGS. -RA CHANCES MINIMAL. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. -RA CHANCES BEGIN TOWARDS THURSDAY MORNING ALONG WITH LOW-END VFR CIGS. MVFR CIGS POSSIBLE THOUGH LOW-CONFIDENCE AT THIS TIME. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF PATCHY MVFR/IFR FOG EACH NIGHT.
-- End Changed Discussion --
&& .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM...THROUGH THURSDAY...HIGH CONFIDENCE. THE MAINLY QUIET BOATING WEATHER CONTINUES. WINDS REMAIN MAINLY E TO SE WITH A FEW GUSTS AROUND 15 KT POSSIBLE ESPECIALLY ACROSS THE OUTER EDGE OF THE S AND SE WATERS. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... MODERATE TO HIGH CONFIDENCE. QUIET BOATING WEATHER IS EXPECTED THROUGH MUCH OF THIS PERIOD WITH HIGH PRESSURE ACROSS THE REGION. LOW PROBABILITY OF PATCHY OVERNIGHT FOG LIMITING VISIBILITIES. SEAS MAY INCREASE ON THE OUTER WATERS THIS WEEKEND AS AN OCEAN STORM PASSES WELL EAST OF THE SOUTHERN NEW ENGLAND WATERS. WNA WAVE GUIDANCE LOOKS TO BE TOO HIGH BASED ON EXPECTED WINDS...LOWERED THIS GUIDANCE BY 20 PERCENT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...BELK/DOODY NEAR TERM...SIPPRELL SHORT TERM...DOODY LONG TERM...BELK AVIATION...BELK/DOODY MARINE...BELK/DOODY

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