Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 280843 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 443 AM EDT SUN JUN 28 2015 .SYNOPSIS... A WINDSWEPT RAIN...HEAVY AT TIMES CONTINUES EARLY THIS MORNING WITH LOCALIZED FLOODING POSSIBLE. RAIN TAPERS OFF TO SHOWERS AND/OR DRIZZLE LATE THIS MORNING AND EARLY AFTERNOON. STRONG EAST WINDS THIS MORNING MAY RESULT IN A FEW DOWN TREE LIMBS/BRANCHES AND ISOLATED POWER OUTAGES. DRY WEATHER RETURNS MONDAY WITH TEMPERATURES SLIGHTLY COOLER THAN NORMAL. WARMER WEATHER ARRIVES TUE AHEAD OF A COLD FRONT WHICH WILL RESULT IN SCATTERED SHOWERS/THUNDERSTORMS TUE NIGHT INTO WED. SOME STORMS MAY BE STRONG WED. BEHIND THE FRONT DRIER WEATHER RETURNS THU. SCATTERED SHOWERS/THUNDERSTORMS POSSIBLE AGAIN FRI AND/OR SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... *** HEAVY RAIN/LOCALIZED FLOOD THREAT AND WINDY CONDITIONS CONTINUE THIS MORNING *** OVERALL THOUGHT PROCESS WITH THE FORECAST REMAINS ON TRACK... THEREFOR NO CHANGES TO THE HAZARDS AT THIS TIME. UPPER LEVEL LOW CURRENTLY OVER THE GREAT LAKES HAS DEVELOPED A SECONDARY SURFACE LOW OVER THE DELMARVA. THIS LOW IS CURRENTLY OVER SOUTH JERSEY AS OF 4 AM. THE DEVELOPMENT OF THIS LOW COMBINED WITH A STRONG LLJ AND TROPICAL CONNECTIONS HAS ALLOWED FOR HEAVY RAIN TO FALL OVERNIGHT AND WINDS TO GUSTS BETWEEN 35-45 MPH ACROSS SOUTH COAST. RAINFALL/FLOODING... WIDESPREAD RAINFALL CONTINUES TO FALL ACROSS THE REGION EARLY THIS MORNING. LOCATIONS ACROSS THE BERKS APPEAR TO HAVE THE HIGHER RAINFALL TOTALS WITH MANY SITES RECEIVING CLOSE TO AN INCH. GUIDANCE CONTINUE TO PINPOINT THIS REGION AS ONE OF THE QPF MAXS SO HAVE CONTINUED THE FLOOD WATCH. LOOKING DOWNSTREAM APPEARS THAT PRECIP IS MORE SHOWERY IN NATURE. HOWEVER AS THE SURFACE LOW CONTINUES TO DEVELOP OVER THE MID- ATLANTIC REGION IT WILL CONTINUE TO STRENGTHEN SURFACE FRONTOGENESIS OVER LONG ISLAND. THIS COMBINED WITH THE STRONG LLJ AND VERY HIGH MOISTURE TRANSPORT...EXPECT PRECIP TO CONTINUE TO DEVELOP AND MOVE NORTHWARD. IN FACT OFF OF SPC MESO PAGE...PWAT VALUES ARE REACHING OVER 2 INCHES JUST SOUTH OF THE REGION...AND WITH THE POTENTIAL FOR SOME ELEVATION CONVECTION...COULD SEE A SECONDARY MAX OVER THE 95 CORRIDOR INTO NE MASS. HI-RES AND SYNOPTIC GUIDANCE CONTINUES TO PINPOINT THIS REGION STILL...SO WILL CONTINUE WITH THE FLOOD WATCH. BIGGEST CONCERN IS THE CONVECTION OFFSHORE. CURIOUS IF IT WILL ROB THE REGION FROM SOME OF THE ACTION. HOWEVER WITH A FIREHOSE OF MOISTURE COMING IN FROM THE EAST...AND UPWARD FLOW OVER THE SURFACE BOUNDARY SOUTH OF LI...ANTICIPATE PRECIP TO CONTINUE INTO THE MID- MORNING HOURS. ONCE THE LOW PRESSURE SYSTEM BEGINS ITS NORTHEASTWARD MOVEMENT...IT WILL PUSH THE BOUNDARY CLOSER TO NEW ENGLAND. THIS WILL ALLOW FOR A DRY SLOT TO DEVELOP AND MOVE THROUGH. ANTICIPATE STEADIER RAIN TO TURN MORE SHOWERY LATE MORNING INTO THE AFTERNOON HOURS. WITH THE DRY SLOT ALOFT...AND AN INVERSION TRAPPING THE LOW LEVEL MOISTURE EXPECT STRATUS/FOG AND DRIZZLE TO DEVELOP THIS AFTERNOON LASTING WELL UNTIL THE EVENING HOURS. DEF NOT AN IDEAL DAY FOR THE FIRST WEEKEND OF SUMMER. WINDS... CONTINUE WITH THE WIND ADVISORY FOR TODAY. MANY SITES ACROSS LONG ISLAND AND THE SOUTH COAST ARE ALREADY RECEIVING GUSTS BETWEEN 35-45 MPH. THE OKX WFO HAD REPORTED SOME TREE DAMAGE EARLY THIS MORNING ACROSS LONG ISLAND...WITH GUSTS AROUND 33 KTS. BELIEVE SATURATED GROUND AND FULLY LEAVED TREES AIDED IN THE DAMAGE REPORT. ONCE THE SUN COMES UP...ANTICIPATE MORE REPORTS TO FILTER INTO THE OFFICE AS GUSTY WINDS BETWEEN 35-50 MPH WILL OCCUR IN THE ADVISORY AREA. 00Z GUIDANCE CONTINUES TO HAVE A GOOD HANDLE ON THE JET WITH 925 MB INCREASING BETWEEN 50-60 KTS AROUND 12Z. THIS JET MAY MIX DOWN WITHIN ANY OF THE HEAVIER SHOWERS OR IF ANY ELEVATED CONVECTION DEVELOPS ALONG THE NOSE OF THE JET. WINDS WILL BEGIN TO DECREASE 10 AM FOR RHODE ISLAND AND CAPE/ISLANDS...CLOSER TIL NOON FOR THE NORTHEAST AREAS. CONVECTION... GUIDANCE CONTINUES TO PUSH THE BOUNDARY FURTHER SOUTH EACH RUN. THEREFORE HAVE A LOW CONFIDENCE IF SNE WILL GET INTO THE WARM SECTOR. IN FACT...HIGH TEMPS TODAY WILL BE QUITE RAW WITH HIGHS REACHING IN THE LOW 60S...WITH 70S RIGHT ALONG THE COAST WHERE WARM FRONT MAY SIT. WE MAY BE A FEW DEGREES SHY OF COOLEST MAX TEMPERATURE. STILL CANT RULE OUT SOME ELEVATED THUND EARLY THIS MORNING ALONG THE NOSE OF THE LLJ...BUT IN TERMS OF SEVERE WEATHER...THE BEST THREAT WILL BE ACROSS THE SOUTHERN WATERS. HIGH SURF... GIVEN SEAS BUILDING TO BETWEEN 7 AND 13 FEET ACROSS OUR OUTER- WATERS...CONTINUES THE HIGH SURF ADVISORY FOR THE SOUTH AND EAST FACING OCEAN EXPOSED BEACHES OF MA/RI. DANGEROUS RIP CURRENTS ARE EXPECTED AS WELL...ALTHOUGH CERTAINLY FAR FROM AN IDEAL BEACH DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... HEAVY RAIN SHOULD BE WELL OVER BY TONIGHT. SURFACE LOW WILL BE MOVING OFFSHORE PUTTING THE REGION BACK INTO A NORTHWEST FLOW. HOWEVER COULD STILL SEE FOG AND DRIZZLE OVER NIGHT WITH THE TRAPPED LOW LEVEL MOISTURE. CONDITIONS WILL IMPROVE BY MONDAY MORNING HOURS. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGHLIGHTS... * DRY AND PLEASANT MONDAY * SCATTERED SHOWERS/T-STORMS POSSIBLE TUE NIGHT/WED AND AGAIN FRIDAY AND/OR SATURDAY WITH MANY HOURS OF DRY WEATHER IN BETWEEN * SOME STORMS MAY BE STRONG WEDNESDAY SYNOPTIC OVERVIEW AND MODEL PREFERENCES... ENSEMBLES AND DETERMINISTIC GUIDANCE IN VERY GOOD AGREEMENT ON THIS HIGH AMPLITUDE PATTERN CONTINUING THIS PERIOD WITH A PERSISTENT RIDGE/HEIGHT ANOMALY OVER WESTERN CONUS/SOUTHWEST CANADA. THIS MAINTAINS A DOWNSTREAM HIGH AMPLITUDE TROUGH WITH ITS MEAN POSITION CENTERED OVER THE GREAT LAKES. THIS RESULTS IN A VERY ACTIVE NORTHERN STREAM JET WITH CYCLONIC FLOW INTO NEW ENGLAND MUCH OF THIS PERIOD...YIELDING A CHANCE OF SHOWERS/T-STORMS ABOUT EVERY OTHER DAY. IN BETWEEN MANY HOURS OF DRY WEATHER ALONG WITH NEAR SEASONABLE TEMPERATURES. AS FOR THE MODEL GUIDANCE...THE OPERATIONAL GFS AND ECMWF ARE IN REMARKABLY GOOD AGREEMENT ON BOTH THE DEPTH AND TIMING OF INDIVIDUAL SHORT WAVES THRU WED. THUS WILL FOLLOW THIS GUIDANCE CLOSELY. HOWEVER BY LATE IN THE WEEK AND INTO NEXT WEEKEND THE DETERMINISTIC GUIDANCE BEGINS TO SHOW ITS TYPICAL SHORT COMINGS AT THIS TIME RANGE WITH LARGE DIFFERENCES IN TIMING AND AMPLITUDE OF INDIVIDUAL TROUGHS. THUS LEANED MORE ON THE ENSEMBLES HERE. DAILY SENSIBLE WEATHER... MONDAY...OPEN MID LEVEL WAVE IN ST LWRN RVR VLY EXITS INTO THE MARITIMES WITH HEIGHT RISES AND WARMING TEMPS ALOFT OCCURRING OVER NEW ENGLAND. DESPITE SOME MODELS GENERATING QPF THIS PATTERN WILL SUPPORT A DRY DAY WITH TEMPS SLIGHTLY COOLER THAN NORMAL. NEVERTHELESS A VERY NICE DAY. TUESDAY...NEXT SHORT WAVE TROUGH APPROACHES THE REGION FROM THE OH VLY. APPEARS WARM FRONTAL CONVECTION IS POSSIBLE TUE BUT LIKELY CONFINED TO THE CT RVR VLY AND WESTWARD INTO NY STATE. THUS MUCH OF SOUTHERN NEW ENGLAND WILL REMAIN DRY. S-SW SURFACE WINDS WILL SUPPORT WEAK LOW LEVEL WAA SO TEMPS CLIMBING INTO THE U70S AND L80S...JUST ABOUT NORMAL FOR LATE JUNE. COOLEST READINGS ALONG THE SOUTH COAST. WEDNESDAY...SHORT WAVE TROUGH CLOSER TO THE REGION YIELDING A HIGHER CHANCE FOR SHOWERS AND T-STORMS THAN TUE. GFS/ECMWF AND GEFS ALL SUGGEST MODEST INSTABILITY AND DEEP LAYER SHEAR FOR THE RISK OF A FEW STRONG T-STORMS. WARM AND HUMID WITH RELIEF ARRIVING WED NIGHT OR THU AS POST FRONTAL AIRMASS OVERSPREADS THE REGION. THU/FRI/SAT...AS MENTIONED ABOVE DETERMINISTIC GUIDANCE BEGINS TO DISPLAY LARGE SPREAD HERE SO LEANED HEAVILY ON THE ENSEMBLES FOR THIS TIME PERIOD...WHICH SUGGEST DRY AND SEASONABLE WEATHER THU BEHIND DEPARTING TROUGH WED. THEN A RISK FOR SHOWERS/T-STORMS FRI AND/OR SAT AS NEXT NORTHERN STREAM TROUGH APPROACHES NEW ENGLAND. TEMPS NEAR SEASONABLE FRI/SAT. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY/... BEFORE 12Z...MODERATE TO HIGH CONFIDENCE. CONDITIONS ARE DETERIORATING TO MVFR AS STEADY -RA CONTINUES TO MOVE ACROSS THE TERMINALS. SITES COULD DROP TO IFR WITHIN ANY +RA. EASTERLY WINDS WILL PICK UP WITH GUSTS NEAR 30 KTS ALONG THE COASTLINES OF RA/MA. AFTER 12Z...MVFR/IFR CONDITIONS AREA WIDE AS +SHRA CONTINUES TO MOVE ACROSS THE REGION. E-SE WIND GUSTS WILL INCREASE BETWEEN 30 TO 40 KNOTS DEVELOPING ALONG THE COAST. LLWS WILL AFFECT THE ENTIRE REGION WITH AN ANOMALOUS EAST TO SOUTHEAST LOW LEVEL JET. EMBEDDED ISOLD THUNDERSTORMS ARE ALSO POSSIBLE ESPECIALLY NEAR THE SOUTH COAST THIS MORNING. RAIN TAPERS OFF TO SCATTERED SHOWERS FROM WEST TO EAST THIS AFTERNOON. HOWEVER...IFR TO LOW END MVFR CONDITIONS LIKELY HANG TOUGH IN LOW CLOUDS AND FOG AND DRIZZLE PATCHES BUT SOME TEMPORARY IMPROVEMENT MAY OCCUR ACROSS RHODE ISLAND AND SOUTHEAST MA AS THE REGION WARM SECTORS. TONIGHT...CONDITIONS WILL STILL HANG TOUGH WITH LIGHT WINDS AND INVERSION OVER THE REGION. EXPECT PATCHY FOG ACROSS THE AREA WITH 2 SM FOG ALONG THE EAST MASS COASTLINE. IMPROVEMENTS AROUND DAYBREAK MONDAY. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS BUT LOW CONFIDENCE IN EXACT TIMING. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS BUT LOW CONFIDENCE IN EXACT TIMING. OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE. MONDAY...VFR AND DRY WEATHER LIKELY. TUESDAY...VFR LIKELY FOR RI AND EASTERN MA WITH LOW RISK OF MVFR ACROSS CT INTO WESTERN-CENTRAL MA IN SCATTERED SHOWERS/T-STORMS. TUE NIGHT AND WED...HIGHEST RISK FOR SHOWERS AND T-STORMS. A FEW STRONG STORMS POSSIBLE. MVFR LIKELY. THU...TRENDING TOWARD VFR AND DRIER AS WELL. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TIL SUNDAY NIGHT/...MODERATE TO HIGH CONFIDENCE. ANOMALOUS LOW PRESSURE SYSTEM WILL RESULT IN WINDS AND SEAS THIS MORNING. STRONGEST WINDS CONTINUE WITH EASTERLY GUSTS BETWEEN 30 AND 40 KNOTS. GALE WARNINGS IN EFFECT FOR ALL WATERS. SEAS ACROSS THE OUTER- WATERS WILL BUILD TO BETWEEN 7 TO 13 FEET BY SUNDAY MORNING. HEAVY RAIN AND A FEW EMBEDDED THUNDERSTORMS EXPECTED EARLY THIS MORNING. OVERALL...SEVERE WEATHER POTENTIAL IS LOW BUT CAN NOT COMPLETELY RULE OUT AN ISOLATED WATERSPOUT ACROSS OUR SOUTHERN WATERS. OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE. MONDAY...ROUGH SEAS ON THE OCEAN WATERS FROM LEFTOVER LARGE SE SWELLS. DRY WEATHER AND GOOD VSBY. TUESDAY...WINDS BECOME SOUTH WITH MAINLY DRY WEATHER AND GOOD VSBY. TUE NIGHT AND WED...S-SW WINDS INCREASE AHEAD OF APPROACHING COLD FRONT. SHOWERS AND T-STORMS BECOME LIKELY AS WELL. THURSDAY...IMPROVING TRENDS WITH FRONT LIKELY WELL OFFSHORE. && .HYDROLOGY... WIDESPREAD RAINFALL OF 1-3 INCHES WITH LOCALLY HIGHER AMOUNTS IS EXPECTED. AT THIS TIME...MOST AREA RIVERS ARE AT THEIR NORMAL SEASONAL LOW POINTS AND SHOULD REMAIN IN THEIR BANKS. HOWEVER...WITH THE VERY HIGH PWATS AND POTENTIAL FOR CONVECTIVE ELEMENTS...ITS POSSIBLE FFG MAY BE EXCEEDED IN SOME AREAS. WIDESPREAD FFG VALUES ARE NEARLY 2.0 INCHES/1 HOUR...2.5 INCHES/3 HOUR...AND 3 INCHES/6 HOUR RATES. NORMALLY FLASHY BASINS/STREAMS MAY NEED TO BE MONITORED. ALSO...URBAN FLOODING WILL BE POSSIBLE AS WELL AS FFG RATES WILL BE LOWER IN THESE LOCATIONS. APPEARS THAT THERE WILL BE 2 MAXIMUM IN QPF. ONE OVER THE EAST SLOPES OF THE BERKSHIRES WITH UPSLOPE FLOW. THE SECOND ONE WILL BE SOMEWHERE OVER EASTERN MA/RHODE ISLAND JUST TO THE NORTHWEST OF THE SURFACE LOW PRESSURE SYSTEM ESPECIALLY IF CONVECTIVE ELEMENTS CAN GET INVOLVED. THOSE ARE THE TWO AREAS WHERE A FLOOD WATCH HAS BEEN ISSUED. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WIND ADVISORY UNTIL NOON EDT TODAY FOR MAZ005>007-013>024. HIGH SURF ADVISORY FROM 8 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR MAZ007-015-016-019>024. FLOOD WATCH UNTIL 2 PM EDT THIS AFTERNOON FOR MAZ005>007- 013>021. FLOOD WATCH THROUGH LATE TONIGHT FOR MAZ002-008-009. RI...WIND ADVISORY UNTIL NOON EDT TODAY FOR RIZ001>008. HIGH SURF ADVISORY FROM 8 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR RIZ006>008. FLOOD WATCH UNTIL 2 PM EDT THIS AFTERNOON FOR RIZ001>007. MARINE...GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR ANZ231>237. GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ230-254>256. GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ250-251. && $$ SYNOPSIS...NOCERA/DUNTEN NEAR TERM...DUNTEN SHORT TERM...DUNTEN LONG TERM...NOCERA AVIATION...NOCERA/DUNTEN MARINE...NOCERA/DUNTEN HYDROLOGY...STAFF

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