399 FXUS61 KBOX 010620 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 220 AM EDT MON JUL 1 2013 .SYNOPSIS... WARM AND MUGGY CONDITIONS WILL CONTINUE WITH HIT AND MISS SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THIS WEEK. THE CHANCES FOR SHOWERS LOWER TOWARD THE END OF THE WEEK INTO NEXT WEEKEND AS HIGH PRESSURE BACKS IN FROM THE WESTERN ATLANTIC. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 230 AM UPDATE... MADE SOME ADJUSTMENTS TO THE FORECAST TO ACCOUNT FOR THE LATEST TRENDS AND FORECAST GUIDANCE. SCATTERED SHOWERS ACROSS THE CAPE/ISLANDS AND THE SOUTHERN WATERS WILL GROW IN AREAL COVERAGE OVER THE NEXT SEVERAL HOURS. LLJ AND MOISTURE PLUME IS AIDING IN THIS DEVELOPMENT. OTHER FOCUS TURNS TO THE SCATTERED SHOWERS AND THUNDERSTORMS OVER PA AND NJ. THIS AREA IS IN A MORE FAVORABLE ENVIRONMENT WITH MLCAPES UP TO 1000 J/KG AND GOOD 850 MB MOISTURE TRANSPORT. MESO-SCALE MODELS SUGGEST THAT THIS CONVECTION WILL OVERSPREAD THE HUDSON VALLEY AND MOVE INTO SNE EARLY THIS MORNING. BOTH OF THE AREAS COMBINED WITH THE CURRENT PWATS OF 2+ INCHES AND DEWPOINTS OF 70+ WILL CAUSE HEAVY DOWNPOURS IMPACTING THE MORNING COMMUTE. BEST REGION WILL BE ACROSS THE CAPE AND INTO CT. TEMPS ARE RUNNING LOW SO HAVE ADJUSTED FORECAST...MANY AREAS WILL NOT GET BELOW 70F THIS MORNING. ANOTHER INDICATION THAT DEWPOINTS ARE QUITE HIGH AND THAT WE ARE IN A TROPICAL AIRMASS. AM CONTEMPLATING A FLASH FLOOD WATCH FOR A PORTION OF THE REGION FOR TODAY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... MONDAY INTO MONDAY NIGHT... THE OVERALL QUESTION...WHERE WILL THE HEAVY RAIN AXIS SETUP AND POTENTIALLY STALL ACROSS THE NORTHEASTERN CONUS? WITH THE BERMUDA HIGH CONTINUING TO RETROGRADE...THERE IS CONFIDENCE THAT THE BETTER SYNOPTICS AND UPPER LEVEL SUPPORT WILL BE PUSHED WEST...ORIENTED ALONG AND IN THE VICINITY OF THE SPINE OF THE APPALACHIAN MOUNTAINS AND COLLOCATED WITH A STATIONARY BOUNDARY ASSOCIATED WITH AN AREA OF LOW PRESSURE OVER WEST-VIRGINIA. EVALUATING H85 FIELDS...MODELS SUCCINCT ON STRONG MOISTURE TRANSPORT AND 10C DEWPOINTS CONVERGING ALONG A LOW- TO MID-LEVEL FRONT FROM THE EASTERN GREAT LAKES REGION THROUGH NORTH-CENTRAL NEW ENGLAND. AND FINALLY...THE BETTER TROPICAL MOISTURE AXIS WITH PWATS EXCEEDING 2-INCHES LIES IS ANTICIPATED TO LIE ACROSS THE EASTERN CONUS SHORE- LINE NORTH INTO SOUTHERN NEW ENGLAND. FEEL A CONTINUOUS CLUSTERING OF SHOWERS AND THUNDERSTORMS WILL FLOW ACROSS THE SPINE OF THE APPALACHIAN MOUNTAINS. SOME OF THIS ENERGY MAY IMPACT WESTERN NEW ENGLAND INCLUDING THE CONNECTICUT RIVER VALLEY INTO THE MONADNOCKS /AN AREA NORTH AND WEST OF A LINE FROM THE HARTFORD-METRO INTO MANCHESTER NH/. WITH GREATER SUBSIDENCE AND DRIER AIR BUILDING INTO SOUTHEAST NEW ENGLAND AND ADJACENT WATERS WITH RETROGRESSING HIGH...HAVE SOME CONCERN WITH POTENTIAL SUNSHINE MORE SO TO THE EAST RESULTING IN SOME INSTABILITY AND INITIATING ADDITIONAL SHOWERS AND THUNDERSTORMS /SO LONG AS THE BUILDING RIDGE DOES NOT SUPPRESS ACTIVITY/. WITH THE UNCERTAINTY OF THE PLACEMENT OF THE HEAVY RAIN AXIS AND THE ASSOCIATED OUTCOMES...WILL NOT GO WITH A FLOOD WATCH OF ANY TYPE WITH THIS FORECAST. WILL HOWEVER NOTE THAT THE POTENTIAL FOR HEAVY RAIN WILL EXIST INTO THE EARLY WEEK PERIOD...HEAVY RAIN IN WHICH COULD RESULT IN LOCALIZED FLASH FLOODING. WARM AND MUGGY CONDITIONS CONTINUE WITH VERY HIGH DEWPOINT AIR. HIGHS GETTING UP IN THE MID- TO UPPER-70S WITH LOWS DOWN AROUND THE MID- TO UPPER-60S. SOUTHERLY WINDS CONTINUE WITH GUSTS UP TO AROUND 20 MPH ACROSS THE SOUTH-SHORE INCLUDING THE CAPE AND ISLANDS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... OVERVIEW AND MODEL PREFERENCES... MEDIUM RANGE MODELS REMAIN VERY CONSISTENT IN KEEPING HIGH AMPLITUDE BLOCKING PATTERN IN PLACE ACROSS THE LOWER 48 THROUGH THIS PERIOD. AS THE LONG WAVE TROUGH ACROSS THE WESTERN U.S. STARTS TO RETROGRADE W...THE WESTERN EXTENT OF THE BERMUDA HIGH WILL ALSO RETROGRADE ALBEIT VERY SLOWLY LATE THIS WEEK AND INTO NEXT WEEKEND. WILL STILL HAVE A THREAT OF SHOWERS/TSTMS THOUGH WILL GRADUALLY LOWER FROM E-W BEGINNING WED OR THU. TROPICAL AIRMASS IN PLACE THROUGH THIS PERIOD WITH PERSISTENT S-SW WIND FLOW IN PLACE. PWATS REMAIN IN THE 2 TO 2.2 INCH RANGE...SO ANY SHOWERS/TSTMS COULD PRODUCE HEAVY RAINFALL. THIS ALONG WITH CONTINUED TRAINING OF CELLS IN THE DEEP SW FLOW WILL KEEP THE THREAT OF LOCALIZED FLOODING GOING. AT THIS POINT...LOOKS LIKE THE BIGGEST THREAT WILL BE ACROSS S NH/CENTRAL AND W MA INTO N CT THROUGH AT LEAST WEDNESDAY. WITH PRETTY GOOD RUN TO RUN CONSISTENCY INTO FRIDAY...LEANED TOWARD A BLEND OF THE WPC GUIDANCE ALONG WITH OUR PREVIOUS FORECAST TO KEEP CONTINUITY GOING. INTO NEXT WEEKEND...DEPENDING UPON WHERE THE RIDGE SETS UP ON THE EASTERN SEABOARD...THE OP MODELS TRY TO RIDE A SHORT WAVE ACROSS THE REGION IN THE FLOW. NOT TOO CONFIDENCE ON THIS FEATURE...HOWEVER...AS SEEN IN THE ENSEMBLES. DETAILS... TUESDAY...WITH START OF RETROGRESSION OF THE RIDGE TO THE W AND UPPER LEVEL TROUGH TO THE W...MAY SEE A SQUEEZE PLAY FOR AREAS OF PRECIP ACROSS THE CENTRAL AND WESTERN ZONES. THIS WILL COMBINE WITH THE HIGH PWATS...DEWPTS AROUND 70 AND TRAINING ANY CELLS TO BRING HEAVY RAINFALL TO THOSE AREAS. KEPT LIKELY POPS GOING IN THOSE AREAS TUE INTO EARLY TUE NIGHT...WITH HIGH CHANCE ELSEWHERE. EXPECT HIGHS IN THE MID 70S TO LOWER 80S...COOLER ALONG THE IMMEDIATE S COAST. WEDNESDAY-THURSDAY...CONTINUE TO NOTE CHANCE POPS ACROSS THE NORTHERN AND WESTERN AREAS...LOOKS LIKE THE COVERAGE WILL BE SLOWLY LOWERING EACH DAY AS THE WESTERN ATLC RIDGE BUILDS W. BEST CHANCES FOR PRECIP WILL BE DURING THE AFTERNOON/EARLY EVENING HOURS EACH DAY...THOUGH CAN NOT RULE OUT SOME ACTIVITY CONTINUING OVERNIGHT. HEAVY DOWNPOURS IN ANY CONVECTION WILL CONTINUE. WITH SOMEWHAT MORE SUNSHINE...SHOULD SEE HIGHS IN THE 80S WITH A FEW SPOTS APPROACHING 90. FRIDAY-SUNDAY...CONTINUED WITH CHANCE POPS ON FRIDAY FOR CENTRAL AND WESTERN AREAS...THEN LOWERED TO SLIGHT CHANCE FOR PRECIP NEXT WEEKEND. LOWER CONFIDENCE INTO NEXT WEEKEND AS OP MODEL RUNS DIVERGE ON THEIR SOLUTIONS...SO KEPT CONSISTENT WITH PREVIOUS FORECAST. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. MODERATE CONFIDENCE IN TRENDS. LOW CONFIDENCE ON TIMING. BEFORE 12Z...MVFR/IFR ACROSS MUCH OR THE REGION WITH LIFR CONDITIONS ACROSS THE CAPE. EXPECT TRENDS TO GENERALLY HOLD THROUGHOUT THE NIGHT. LOW STRATUS WILL CONTINUE TO EXPAND SO A FEW SITES MAY FALL. FOG DEVELOP IS FEW AND FAR BETWEEN SO THIS IS LESS OF A CONCERNS. THERE IS AN INCREASING CHANCE FOR SHOWERS/SCT TSTMS ACROSS ALL SITES THROUGH THE REMAINDER OF THE NIGHT. AFTER 12Z...CONDITIONS WILL SLOWLY IMPROVE DURING THE DAY EITHER ALL MVFR OR POSSIBLY TO LOW-END VFR ACROSS THE INTERIOR...BUT FALTER INTO MONDAY EVENING. THERE IS SOME POSSIBILITY OF POTENTIAL CLEARING ACROSS THE FAR SOUTHEAST TERMINALS LATE IN THE PERIOD...LOW CONFIDENCE. OTHERWISE WIDESPREAD SHRA/TSRA WILL IMPACT ALL SITES. TONIGHT...MAINLY MVFR/IFR ACROSS MANY SITES. LOW CONFIDENCE IN FOG. EXPECT ON AND OFF SHOWERS WITH ISOLATED THUNDER OVERNIGHT WHICH WILL DROP SITES TO IFR/LIFR. BEST REGION FOR THIS TO OCCUR IS FROM KBAF TO KMHT AND NORTHWEST. TUESDAY...EXPECT GRADUAL IMPROVEMENT THROUGHOUT THE DAY. POSSIBLE REACHING VFR. OTHERWISE ANOTHER ROUND OF SHOWERS/THUNDERSTORMS WILL DROP TERMINALS TO MVFR/IFR. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS. MVFR/VFR CONDITIONS CURRENTLY DROP TO MVFR CIGS TONIGHT. OTHERWISE SLIGHT IMPROVEMENT TODAY UNTIL SHRA/TSRA DROPPING TO MVFR/IFR. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS. IFR IN STRATUS NOW...IMPROVING TO MVFR TODAY. OTHERWISE EXPECT SHRA/TSRA DROPPING CONDITIONS TODAY UNTIL TUESDAY. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... MODERATE CONFIDENCE. NO CHANGES IN THE WEATHER PATTERN THROUGH MOST OF THE WEEK. THIS WILL MEAN SHOWERS AND SCATTERED TSTMS THROUGH AT LEAST THURSDAY...SOME WITH HEAVY DOWNPOURS. THE DAYTIME MAY HAVE A BASELINE OF VFR...BUT WITH MVFR-IFR CIGS AND VSBYS IN ANY SHOWERS/TSTMS. THE VERY HUMID AIRMASS LINGERS THROUGH THE PERIOD...SO LATE NIGHT AND EARLY MORNING FOG WILL BRING IFR-LIFR CIGS/VSBYS. THE LOW CLOUDS AND FOG MAY LINGER DURING THE DAYTIME ACROSS PARTS OF THE CAPE AND ISLANDS. && .MARINE... 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. EXPANDED SMALL-CRAFT ADVISORIES ACROSS THE OPEN WATERS FOR THE PERIOD. GUSTS UP TO 25 KTS WILL BE POSSIBLE...EVEN INTO THE INNER WATERS OF CAPE COD AND THE ISLANDS DURING THE DAY. ADDITIONAL HAZARDS INCLUDE CLUSTERS OF SHOWERS AND THUNDERSTORMS...ALONG WITH FOG ACROSS THE SOUTH-SHORE WATERS. VISIBILITIES LESS THAN ONE NAUTICAL MILE OR LESS WILL BE POSSIBLE AT TIMES...ESPECIALLY DURING THE EVENING PERIODS. OUTLOOK...TUESDAY THROUGH FRIDAY... MODERATE CONFIDENCE THROUGH THE PERIOD. TUESDAY-WEDNESDAY...S WINDS CONTINUE WITH GUSTS UP TO 20 KT. SEAS UP TO 5-7 FT MAINLY ON THE OUTER WATERS WITH LONG SW GROUND SWELLS CONTINUING. PATCHY VSBYS BELOW 1SM IN FOG MAINLY DURING THE NIGHTTIME HOURS. THURSDAY-FRIDAY...SW WINDS WILL GUST UP TO 20-25 KT...HIGHEST ON THE OUTER WATERS. SEAS UP TO AROUND 5 FT OR SO WITH LOWERED VSBYS IN PATCHY FOG. && .CLIMATE... WITH SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN CONTINUING INTO THE WEEKEND...WE WILL BE ADDING TO THE ALREADY HIGH MONTHLY TOTALS FOR RAIN DAILY. BELOW PLEASE FIND THE TOP 5 WETTEST JUNE RAINFALL TOTALS FOR EACH OF OUR FOUR CLIMATE SITES...THESE INCLUDE RAINFALL TOTALS FOR JUNE 2013 ENDING AT 1 AM THE MORNING OF JUNE 30TH... BOSTON... 1. 13.20 INCHES IN 1982 2. 11.58 INCHES IN 1998 3. 10.39 INCHES IN 2013 4. 10.09 INCHES IN 2006 5. 9.13 INCHES IN 1931 HARTFORD... 1. 13.60 INCHES IN 1982 2. 10.79 INCHES IN 2013 3. 9.66 INCHES IN 1972 4. 9.16 INCHES IN 2006 5. 8.08 INCHES IN 1937 PROVIDENCE... 1. 11.08 INCHES IN 1982 2. 9.90 INCHES IN 2013 3. 9.61 INCHES IN 1998 4. 9.24 INCHES IN 2006 5. 7.21 INCHES IN 1938 WORCESTER... 1. 12.17 INCHES IN 1982 2. 10.06 INCHES IN 2013 3. 9.68 INCHES IN 1998 4. 9.25 INCHES IN 1972 5. 8.31 INCHES IN 1922 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ235-237-250- 254>256. && $$ SYNOPSIS...SIPPRELL/EVT NEAR TERM...DUNTEN SHORT TERM...SIPPRELL LONG TERM...EVT AVIATION...DUNTEN/EVT MARINE...EVT CLIMATE...STAFF