591 FXUS61 KBOX 100425 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1224 AM EDT MON JUN 10 2013 .SYNOPSIS... HIGH PRESSURE OVERHEAD WILL RESULT IN A BEAUTIFUL END TO THE WEEKEND. LOW PRESSURE MOVING OUT OF GREAT LAKES WILL BRING MORE RAIN AND SOME THUNDERSTORMS FROM LATE MONDAY THROUGH MOST OF TUESDAY. A WARM FRONT WILL PUSH THROUGH ON TUESDAY...FOLLOWED BY A COLD FRONT TUESDAY NIGHT. ADDITIONAL DISTURBANCES WILL MOVE ACROSS ON WEDNESDAY THROUGH FRIDAY. HIGH PRESSURE WILL BRING DRY SEASONABLE CONDITIONS FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1220 AM UPDATE... MOSTLY CLEAR SKIES VERY EARLY THIS MORNING SHOULD GIVE WAY TO AN INCREASE IN MID/HIGH LEVEL CLOUDS FROM WEST TO EAST THROUGH DAYBREAK. STILL NOT EXPECTING A SOLID OVERCAST AND HIGH PRESSURE OVERHEAD WILL ALLOW GOOD RADIATIONAL COOLING CONDITIONS TO CONTINUE. LOWS BY DAYBREAK SHOULD BE MAINLY IN THE 50S. A TOUCH OF PATCHY GROUND FOG MAY DEVELOP IN THE TYPICALLY PRONE LOCATIONS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... MONDAY INTO MONDAY NIGHT... SURFACE HIGH PRESSURE WILL MOVE OFFSHORE BY MONDAY MORNING. MID TO HIGH LEVEL CLOUDS MOVE OVERHEAD FROM WEST TO EAST IN ADVANCE OF OUR NEXT WEATHER PRODUCER. UPPER LEVEL TROUGH ACROSS THE MIDWEST WILL PUSH EASTWARD ADVANCING A WARM FRONT THROUGH SOUTHERN NEW ENGLAND LATE MONDAY INTO THE OVERNIGHT HOURS. MODELS: OVERALL MODEL GUIDANCE IS IN GENERAL AGREEMENT WITH THIS APPROACHING SYSTEM. THE TIMINGS ARE QUIET SIMILAR...HOWEVER THE EXACT PLACEMENT OF THE HEAVIER PRECIP/WARM FRONT IS SLIGHTLY OFF. TRENDED THIS FORECAST WITH WPC/12 EC WHICH APPEARS TO HAVE A GOOD HANDLE ON THE SYSTEM. MODELS PUSH THE WARM FRONT THROUGH THE REGION VERY QUICKLY...HOWEVER THERE IS A GOOD AMOUNT OF LIFT AND MOISTURE TRANSPORT SO EXPECT THE RAIN TO STICK AROUND FOR SOME TIME. PRECIP/QPF: THE GFS MODELS PUTS THE BULLS-EYE OF QPF ACROSS THE NORTHERN BERKSHIRES INTO SOUTHERN NEW HAMPSHIRE. THE EC PUTS THE QPF BULLS-EYE WEST OF THE WORCESTER HILLS AND INTO CT. TRENDED THE QPF FORECAST TOWARDS NERFC AND THE EC TO ACCOUNT FOR MODEL DISCREPANCY. OVERALL IT APPEARS THAT A GOOD 1 TO 2 INCHES OF QPF WILL OCCUR WITH ISOLATED HIGHER AMOUNTS AS CONVECTION WILL ALLOW FOR HEAVY DOWNPOURS. ESP WHEN PWAT VALUES ARE 2.0 INCHES...COULD NOT RULE OUT ISOLATED 3 INCH AMOUNTS IN STORM TOTAL QPF. NORTH OF THE MASS PIKE HAS THE BEST CHANCE TO SEE THE 2+ INCH AMOUNTS. THUNDER: AS THE WARM FRONT MOVES THROUGH...IT WILL PUT SOUTHERN NEW ENGLAND IN THE WARM SECTOR. THIS WILL INCREASE DEWPOINTS INTO THE UPPER 60S. COMBINED WITH AN APPROACHING JET STREAK...LIS BELOW 0 COULD SEE SOME RUMBLES OF THUNDER...EMBEDDED CONVECTION WITHIN PRECIPITATION SHIELD. AM NOT ANTICIPATED THUNDERSTORMS TO BE STRONG/SEVERE...MAIN CONCERN FOR THE OVERNIGHT PERIOD WOULD BE HEAVY DOWNPOURS. FLOOD POTENTIAL IS INCREASING...SEE HYDROLOGY SECTION BELOW. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... OVERVIEW AND MODEL PREFERENCES... UPPER FLOW WILL FEATURE TROUGHS ALONG THE TWO COASTS WITH A RIDGE OVER THE PLAINS. THE RIDGE WILL BUILD EAST OVER THE WEEKEND. WE USED A BLEND OF LONG RANGE GFS AND ECMWF GRIDS. DETAILS... TUESDAY... LOW PRESSURE PASSING TO OUR WEST AND NORTH WILL SLOWLY PULL A WARM FRONT NORTH THROUGH THE REGION. A 40 KNOT LOW LEVEL SOUTHWEST JET WILL RIDE OVER THE TOP OF THIS FRONT PROVIDING LOW LEVEL CONVERGENCE...AND AN UPPER JET WILL MOVE ACROSS PROVIDING UPPER VENTING. PRECIPITABLE WATER VALUES WILL START THE DAY AT 2 INCHES AND REMAIN ABOVE 1.5 INCHES THROUGH THE DAY. UNSTABLE CONDITIONS IN THE WARM SECTOR WITH LI/S BELOW ZERO. PUT IT ALL TOGETHER...EXPECT SHOWERS/TSTMS WITH LOCALLY HEAVY DOWNPOURS. THIS WILL BRING POTENTIAL FOR RENEWED FLOODING CONCERNS. A LESSER BUT STILL REAL CONCERN IS FOR A FEW TSTMS APPROACHING SEVERE LEVELS IN THE WARM SECTOR...ESPECIALLY WITH ANY BREAKS OF SUN AND RESULTING HEATING OF THE AIRMASS. THE LOW PASSES TUESDAY NIGHT AND PULLS A COLD FRONT THROUGH THE REGION. SHOWERS/TSTMS SHOULD DIMINISH AS WE GET BEHIND THE FRONT LATER AT NIGHT. WEDNESDAY...THE UPPER LOW AND COLD POOL MOVE OVER THE REGION. THE COLD POOL AND ANY SOLAR HEATING WILL DESTABILZE THE AIRMASS. MEANWHILE AN 85 KNOT UPPER JET WILL MOVE ACROSS AND PROVIDE RENEWED UPPER VENTING. THIS SHOULD GENERATE CLOUDS AND SCATTERED SHOWERS/TSTMS. DAYTIME MIXING WILL ALSO TAP 25-30 KNOT WINDS ALOFT AND BRING THEM TO THE SURFACE IN GUSTS. THURSDAY...ANOTHER SHORTWAVE MOVES ACROSS. THE COLD POOL ALOFT WILL HAVE MOVED OFF...SO MUCH LESS DESTABILIZATION. EVEN SO...EXPECT SOME CLOUDS AND WIDELY SCATTERED SHOWERS. FRIDAY...ONE MORE SHORTWAVE MOVES DOWN FROM THE NORTHWEST. THIS WILL BE SUPPORTING A SURFACE COLD FRONT WHICH WILL MOVE ACROSS SOUTHERN NEW ENGLAND LATE FRIDAY AND FRIDAY NIGHT. AS IT PASSES WE EXPECT SCATTERED OR WIDELY SCATTERED SHOWERS. SATURDAY-SUNDAY...HIGH PRESSURE BUILDS OVER THE REGION AND WILL BRING DRY AND SEASONABLE WEATHER. TEMPS MAY ACTUALLY WARM A LITTLE MORE ON SUNDAY AS THE HIGH MOVES OFFSHORE AND WARM AIR MOVES IN ALOFT. THE WARM AIR ALOFT WILL ALSO BRING SOME INCREASE IN MID AND HIGH CLOUDS. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. OVERVIEW... TONIGHT...HIGH CONFIDENCE. VFR CONDITIONS WILL DOMINATE. HOWEVER...SOME PATCHY FOG WILL RESULT IN LOCALIZED LOWER CONDITIONS EARLY MONDAY MORNING IN THE TYPICALLY FOG-PRONE LOCATIONS. MONDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE. VFR TO START BEFORE CONDITIONS DETERIORATE SOUTHWEST TO NORTHEAST BY LATE AFTERNOON TO MVFR. IFR AND LIFR POSSIBLE MONDAY EVENING INTO THE OVERNIGHT AS SHRA/TSRA MOVES THROUGH THE REGION. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY THROUGH FRIDAY... MODERATE CONFIDENCE THROUGH PERIOD. TUESDAY...IFR CIGS ALONG WITH SHOWERS AND TSTMS AS A WARM FRONT TRIES TO MOVE ACROSS THE AREA. LOCALLY HEAVY DOWNPOURS POSSIBLE. SOUTHEAST WINDS SHIFT TO SOUTHWEST DURING THE DAY WITH GUSTS OF 20-25 KNOTS. WEDNESDAY...CIGS/VSBYS MAINLY MVFR IN SCT SHOWERS DURING THE DAY WITH POCKETS OF LOW END VFR. CONDITIONS SHOULD IMPROVE TO VFR WED NIGHT. WEST TO NORTHWEST WINDS WILL BECOME GUSTY WITH GUSTS OF 25 TO 30 KNOTS. THURSDAY-FRIDAY...GENERALLY VFR. CHANCE OF LOWER CIGS/VSBYS IN AFTERNOON AND NIGHTTIME SHOWERS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. 1220 AM UPDATE... HIGH CONFIDENCE THROUGH MONDAY...MODERATE CONFIDENCE MONDAY EVENING INTO THE OVERNIGHT. SCA HAVE ALL BEEN ALLOWED TO EXPIRE AS SEAS HAVE DIMINISHED BELOW 5 FEET ACROSS ALL OUR WATERS. SEAS/WINDS WILL REMAIN BELOW SCA THRESHOLDS THROUGH MONDAY AFTERNOON. AN APPROACHING WARM FRONT MONDAY EVENING WILL HELP INCREASE WIND AND SEAS ACROSS THE WATERS. SCA WILL BE NEEDED BY LATE MONDAY NIGHT. EXPECT LOW VSBYS AS WELL IN HEAVY SHOWERS AND THUNDERSTORMS. OUTLOOK...TUESDAY THROUGH FRIDAY... TUESDAY...EXPECT SOUTH TO SOUTHEAST WINDS TO SHIFT TO SOUTHWEST. SOUTHWEST WINDS MAY GUST UP TO 25 KNOTS NEAR SHORE. SEAS WILL BUILD...WITH 5 TO 8 FEET ON THE SOUTHERN EXPOSED WATERS AND 5 FEET ON THE EASTERN OUTER WATERS. LOWERED VSBYS IN SHOWERS AND TSTMS DURING THE DAY. WEDNESDAY...WEST TO NORTHWEST WINDS WILL MAY GUST UP TO 25 KNOTS NEAR SHORE DURING THE DAY. SEAS WILL LINGER AT 5 TO 8 FEET ON THE SOUTHERN EXPOSED WATERS AND 5 FEET ON THE EASTERN OUTER WATERS. THURSDAY...SEAS DIMINISHING BELOW 5 FEET. WINDS REMAIN BELOW 25 KNOTS. FRIDAY...WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT THRESHOLDS. && .HYDROLOGY... A RIVER FLOOD WARNING REMAINS IN EFFECT FOR PAWTUXET AT CRANSTON. THE RIVER HAS CRESTED JUST ABOVE 11 FEET...WHICH IS ABOVE THE FLOOD STAGE OF 9.0 FEET...AND WILL SLOWLY FALL. THERE WILL BE ANOTHER ROUND OF HEAVY RAINFALL WILL MOVE IN AHEAD OF AN APPROACHING WARM FRONT MONDAY NIGHT AND TUESDAY. QPF AMOUNTS ARE BETWEEN 1.5 AND 2 INCHES...WITH THE HIGHEST AMOUNTS CURRENTLY ACROSS CENTRAL AND W MA/N CT AND SW NH. IF THIS COMES TO FRUITION...COULD SEE RENEWED FLOODING OF SMALL STREAMS AS WELL AS URBAN AND POOR DRAINAGE FLOODING. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/DUNTEN NEAR TERM...FRANK SHORT TERM...DUNTEN LONG TERM...WTB AVIATION...WTB/DUNTEN MARINE...FRANK/DUNTEN/WTB HYDROLOGY...STAFF