FXUS61 KBOX 120552 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1252 AM EST FRI MAR 12 2010 .SYNOPSIS... HIGH PRESSURE TO OUR NORTH WILL RESULT IN MAINLY CLOUDY AND COOL WEATHER TONIGHT AND FRIDAY. A STRONG STORM WILL THEN MOVE OFF THE MID ATLC COAST BRINGING MAINLY RAIN AND OCCASIONALLY WINDY WEATHER THIS WEEKEND INTO MONDAY. MUCH NICER WEATHER FOLLOWS BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SHOWERS HAVE DECREASED IN COVERAGE OVER THE PAST HOUR. THUS HAVE LOWERED POPS TO SLIGHT TO LOW CHANCE...EXCEPT LIKELY FOR THE NEXT HOUR OR TWO ACROSS EXTREME NE MASSACHUSETTS. SPOTTY LIGHT PRECIPITATION WILL LINGER WITH CONTINUED ISENTROPIC LIFT. SOME PATCHY LIGHT FREEZING DRIZZLE IS POSSIBLE ACROSS THE INTERIOR LATER TONIGHT BUT WILL CONTINUE TO MONITOR. REMAINDER OF THE FORECAST LOOKS GOOD. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... FRIDAY... A 1030 MB HIGH PRESSURE SYSTEM OVER EASTERN CANADA WILL BEGIN TO NOSE DOWN INTO EASTERN NEW ENGLAND. THIS MAY TEMPORARILY SEND A BIT OF DRIER AIR DOWN FROM THE NORTHEAST INTO OUR REGION. THEREFORE...DO NOT SEE MUCH THREAT OF PRECIPITATION ON FRIDAY. WILL GO WITH MAINLY A DRY FORECAST ACROSS OUR NORTHERN/EASTERN ZONES...WITH JUST SOME 20 TO 30 POPS ACROSS OUR WESTERN/SOUTHERN ZONES. THE BEST CHANCE OF ANY MEASURABLE LIGHT RAIN SHOWERS WILL BE ACROSS THE EAST SLOPES OF THE BERKSHIRES...BUT ANY AMOUNTS THAT FALL SHOULD BE QUITE LIGHT. IN FACT...WOULD NOT BE SURPRISED TO SEE SOME PEEKS OF SUNSHINE ACROSS OUR NORTHERN AND EASTERN ZONES. ONSHORE FLOW SHOULD KEEP HIGHS IN THE MID TO UPPER 40S. THE COOLEST READINGS WILL BE FOUND NEAR SHORE. FRIDAY NIGHT... THERE ARE STILL SOME TIMING DIFFERENCES AMONGST THE MODELS. HOWEVER...THE MODELS DO AGREE IN A DEVELOPING SOUTHEAST LOW LEVEL JET OVERNIGHT. THIS WILL INDUCE MID LEVEL LIFT AND EXPECT STEADY RAIN TO OVER SPREAD PORTIONS OF THE REGION FROM SOUTHWEST TO NORTHEAST OVERNIGHT. WILL INCREASE POPS TO LIKELY ACROSS OUR SOUTHWEST ZONES TOWARDS 12Z SATURDAY WITH CHANCE POPS BY THEN ACROSS OUR NORTHEAST ZONES. THE VAST MAJORITY OF THE PRECIPITATION WILL BE IN THE FORM OF RAIN. HOWEVER...THERE IS THE POTENTIAL FOR SOME FREEZING RAIN ACROSS THE HIGHER TERRAIN OF THE EAST SLOPES OF THE BERSHIRES AND THE MONADNOCKS IN SOUTHERN NH. THE MODELS ARE INDICATING 925 MB TEMPERATURES BETWEEN 0 AND -2C TOWARDS 12Z SATURDAY WITH A COLD AIR DAMNING SIGNATURE. SURFACE TEMPERATURES WILL BE MARGINAL AND A LOT OF THE POTENTIAL WILL DEPEND ON WHEN EXACTLY THE PRECIPITATION ARRIVES AND THE EXACT TEMPERATURE. HOWEVER...THERE IS A CHANCE THAT A WINTER WEATHER ADVISORY MAY EVENTUALLY BE NEEDED FOR OUR DISTANT INTERIOR HIGH TERRAIN. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... NOT MUCH CHANGE ANTICIPATED FROM PREV FCST WITH WEEKEND STORM. THERE ARE STILL UNCERTAINTIES WITH HOW MID LEVEL LOW EVOLVES AND THIS HAS IMPACTS ON WIND/QPF FIELD BUT WE HAVE HIGH CONFIDENCE OF HEAVY RAINFALL EVENT HERE SAT THROUGH SUN. OTHER POTENTIAL HAZARDS ARE STRONG WIND ALONG THE COAST...DISTANT INTERIOR ICE AND MINOR COASTAL FLOODING. VERY COMPLEX UPPER AIR PATTERN WITH NUMEROUS SHORTWAVES ROTATING AROUND MID LEVEL LOW WHICH WILL MAKE IT VERY DIFFICULT TO RESOLVE EVOLUTION OF PRIMARY AND SECONDARY LOWS. EVENTUALLY CONSOLIDATED LOW WILL ORGANIZE NEAR OR SE OF THE BENCHMARK BY EARLY MON. EXACTLY HOW WE GET THERE IS STILL UNCERTAIN. WE DO NOT LIKE THE GFS DEPICTION OF STRONG LEAD WAVE ALONG MID ATLC COAST FOR SAT AFTERNOON/EVENING WHICH RESULTS IN VERY STRONG LLJ APPROACHING 100 KT AT 850 MB NEAR LONG ISLAND BY 00Z SUN. GFS APPEARS TO BE DEALING WITH FEEDBACK ISSUES AND MODEL CONSENSUS SHOWS STRONGER PRIMARY LOW AND WEAKER COASTAL LOW TO THE EAST. WE LARGELY ARE RELYING ON ECMWF FOR THIS FORECAST WHICH HAS SHOWN GOOD RUN TO RUN CONSISTENCY. STEADY RAIN MOVES INTO SNE FROM SW TO NE DURING SAT. THERE IS A LOW PROB OF SOME FREEZING RAIN/SLEET WHICH COULD REQUIRE WWA ACROSS FAR NW MA AND SW NH LATE FRI NIGHT OR EARLY SAT IF PRECIP COMES IN BY 12Z SAT AS THERE IS ENOUGH LEVEL COLD AIR IN PLACE. BUT IF THERE IS ANY DELAY IN THE PRECIP SHIELD...ICING PROBLEMS WOULD BE MINIMIZED AS SOME WARMING OCCURS DURING THE DAY. IT APPEARS HEAVIEST OF THE RAINFALL WILL OCCUR SAT NIGHT ACROSS SNE AS LLJ AXIS MOVES NORTHWARD ACROSS THE REGION. HEAVIER RAINFALL MAY BEGIN BY SAT AFTERNOON SW ZONES. LLJ BEGINS TO LIFT NORTHWARD LATE SAT NIGHT SHIFTING TO NORTHERN NEW ENG DURING SUN. BUT SOUTHERN EDGE OF THE JET REMAINS NEARLY STATIONARY ACROSS N ZONES DURING SUN WHICH MAY KEEP PERIODS OF HEAVY RAIN ACROSS NE MA AND S NH WHILE DRY SLOT BRINGS DIMINISHING RAINFALL SOUTH OF THE PIKE DURING SUN. SOME ICING IS POSSIBLE FAR NW ZONES AGAIN SAT NIGHT AND EARLY SUN AS LOW LEVEL COLD AIR REDEVELOPS AT NIGHT. ALSO LOW PROB OF SOME WET SNOW HIGHER ELEVATIONS AS THE COLUMN COOLS AND LOW AND MID LEVEL THICKNESS PROFILES BECOME MARGINALLY COLD ENOUGH FOR SNOW. BOTH GFS AND ECMWF SHOW THIS AND IF THERE IS STRONG ENOUGH OMEGA MOVING ACROSS THE REGION THIS COULD BE ENOUGH TO PRODUCE A PERIOD OF WET SNOW WITH SOME ACCUM FOR NORTHERN BERKSHIRES AND MONADNOCKS. CONFIDENCE IS LOW BUT THIS POSSIBILITY WILL NEED TO BE MONITORED DURING LATER FORECASTS. SUN NIGHT...MAY SEE SOME MINOR SNOW ACCUM FAR NW ZONES AS ATMOSPHERE COOLS. ECMWF IS SUGGESTING THIS BUT GFS DRIES IT OUT. QPF AND FLOOD POTENTIAL... MOST OF THE MODEL GUIDANCE IS IN VERY GOOD AGREEMENT WITH AXIS OF MAX RAINFALL NEAR THE I95 CORRIDOR. +4 SD EASTERLY INFLOW IS IMPRESSIVE WHICH FAVORS HEAVY RAINFALL EVENT BUT PWAT ANOMALY +1/+2 SD NOT AS HIGH AS I WOULD TO SEE IT FOR REAL EXCESSIVE RAINFALL AMOUNTS. LLJ IS FAIRLY PROGREEIVE WHICH MAY ALSO LIMIT DURATION OF HEAVIEST RAINFALL TO SAT NIGHT. ALSO GEFS PROBS OF 3"/36HR HAVE DECREASED AND ARE NOW ZERO. SREF SHOWING 30-50% PROB OF 3" EASTERN NEW ENG. CURRENT THINKING IS 1-3" RAINFALL EVENT WITH ISOLD 4" TOTALS. MAX RAINFALL CENTRAL AND EASTERN NEW ENG...POSSIBLY EXTENDING NORTHWARD TO MERRIMACK BASIN IF HEAVY RAIN PERSISTS IN LLJ AXIS DURING SUNDAY. CURRENT THINKING IS MODERATE TO HIGH PROB OF MINOR FLOODING. STRONG WIND POTENTIAL... HIGH PROB OF WIND ADVISORY CRITERIA SAT NIGHT...ESPECIALLY NEAR THE COAST AS EASTERLY LLJ /60-70 KT AT 925 MB/ MOVES NORTHWARD ACROSS THE REGION. LOW PROB OF HIGH WIND WARNING CRITERIA IF GOOD PRES FALLS DEVELOP. COASTAL FLOODING/BEACH EROSION... WHILE ASTRO TIDES ARE LOW...THINK PERSISTENT GALE FORCE EASTERLY FLOW WILL BRING STORM SURGE UP TO 2 FEET DURING HIGH TIDE CYCLES FROM SAT NIGHT THROUGH SUN NIGHT. WITH 20+ FOOT SEAS DEVELOPING OFFSHORE THIS WOULD BE ENOUGH TO GENERATE MINOR COASTAL FLOODING ALONG THE EAST COAST WITH LOW PROB OF LOW END MODERATE FOR SUCCESSIVE TIDE CYCLES. IN ADDITION IF WATER LEVELS BECOME HIGHER THAN PREDICTED BY THE GFS STORM SURGE MODEL COMBINED WITH LARGE SEAS POUNDING THE SHORELINE...THERE MAY BE A GREATER RISK OF SIGNIFICANT BEACH EROSION. MONDAY THROUGH THURSDAY... THE LOW PRESSURE SYSTEM PLAGUING US ALL WEEKEND IS MUCH SLOWER TO DEPART ON THE ECMWF THAN ON THE GFS. HAVE OPTED FOR THIS SLOWER SCENARIO WITH THE 990 MB LOW STILL WELL TO THE SOUTHEAST OF NANTUCKET DURING THE AFTERNOON. SKIES MAY CLEAR OUT TO THE NORTH AND WEST OF SOUTHERN NEW ENGLAND DURING THE DAY BUT FOR NOW AM EXPECTING CLOUDINESS HERE WHICH WILL KEEP TEMPERATURES WELL BELOW MAVMOS VALUES. GFS HAS HIGHS INTO LOWER 50S WITH SUNSHINE BUT HAVE GONE WITH PREVIOUS FORECAST HIGHS OF 40 TO 45 MOST AREAS AND A CONTINUING CHANCE OF RAIN...ESPECIALLY IN THE SOUTHEAST. ECMWF TEMPS AT 850 MB ARE -1C TO -2C WITH AN ISOTHERMAL PROFILE IN THE LOW LEVELS WHICH COULD MEAN SOME WET SNOWFLAKES TOO...BUT ITS SURFACE TEMPERATURES ARE IN THE UPPER 30S MOST OF THE DAY WHICH WOULD MEAN MOSTLY RAIN AND NOTHING STICKING TO THE GROUND. FOR NOW 40 TO 45 SEEMS BEST COMPROMISE. FORECAST GETS MUCH EASIER AFTER THAT. SKIES WILL CLEAR LATER MONDAY NIGHT. HIGH PRESSURE BUILDS INTO THE AREA TUESDAY LEADING TO A FINE ALMOST-SPRING DAY. WITH ABUNDANT SUNSHINE WE SHOULD REACH HIGHS FROM 53 TO 57 EXCEPT COOLER ON THE CAPE AND ISLANDS. A COOL FRONT IS FORECAST TO MOVE THROUGH IN THE TUESDAY NIGHT OR WEDNESDAY TIME FRAME BUT IT WILL BE DRY AND LARGELY UNNOTICED EXCEPT FOR KICKING UP SOME NORTHERLY WIND GUSTS TO 20 KTS OVER THE WATERS. HIGH PRESSURE FROM THE OHIO VALLEY TO THE EAST COAST WILL LEAD TO SUNSHINE WEDNESDAY WITH HIGHS AGAIN NEAR 50. ON THURSDAY...WE ARE FORECASTING PARTLY SUNNY CONDITIONS...JUST A BIT MORE HIGH CLOUDINESS IN ASSOCIATION WITH A JET MAXIMUM PASSING ACROSS SOUTHERN QUEBEC. OUR HIGHS SHOULD REACH 50 TO 55. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... TONIGHT...A PERIOD OF MVFR CIGS IS DEVELOPING FROM HFD-WST AND WILL CONTINUE TO EXPAND AS LOWER CLOUDS FROM LONG ISLAND AND COASTAL CT LIFT NWD. HIGHEST CONFIDENCE OF MVFR BAF-BDL-ORH-PVD. DRIER AIR TO THE NORTH WILL LIKELY PREVENT LOWER CIGS FROM MAKING IT TO BOS-MHT WHERE HIGH CONFIDENCE VFR CIGS EXPECTED. FRIDAY...MODERATE CONFIDENCE IN MAINLY VFR CEILINGS ACROSS THE MHT/BOS/FMH/HYA/ACK SITES DESPITE MID LEVEL CLOUDINESS. MODERATE CONFIDENCE IN MARGINAL MVFR-VFR CEILINGS ACROSS BDL/BAF/ORH/PVD TERMINALS. EASTERLY WIND GUSTS OF 20 TO 25 KNOTS MAY DEVELOP DURING THE AFTERNOON TO THE SOUTH OF MA TURNPIKE. FRIDAY NIGHT...MODERATE CONFIDENCE THAT MVFR-IFR CONDITIONS WILL OVERSPREAD THE REGION IN RAIN FROM SOUTHWEST TO NORTHEAST. OUTLOOK... SAT...MVFR LOWERING TO IFR FROM SW TO NE. E G35 KTS DEVELOPING NEAR THE COAST. ICE POSSIBLE NORTHWEST MA AND SOUTHWEST NH EARLY SAT. LOW CONFIDENCE ON TIMING OF MVFR TO IFR. SAT NIGHT...HIGH CONFIDENCE ON IFR IN WIND DRIVEN RAIN. STRONG EAST WINDS 30-40 KT EASTERN MA ALONG WITH PROBABLE LLWS. SUN...HIGH CONFIDENCE IFR/LIFR IN RAIN/DRIZZLE FOG...POSSIBLY CHANGING TO SNOW AT NIGHT ORH AND OTHER HIGH TERRAIN TERMINALS. MON...MVFR CIGS BECOMING VFR NW HALF. MVFR CIGS AND AREAS OF RAIN OR RAIN MIXED WITH SOME WET SNOW SE HALF WITH LOCAL IFR CIGS/VSBY IN THE MORNING. MODERATE CONFIDENCE. MON NIGHT...HIGH CONFIDENCE OF BECOMING VFR. TUESDAY...HIGH CONFIDENCE VFR. && .MARINE... TONIGHT... WINDS AND SEAS WILL REMAIN BELOW SCA THRESHOLDS WITH WEAK PRESSURE GRADIENT IN PLACE. FRIDAY AND FRIDAY NIGHT... LOW PRESSURE MOVING EAST INTO THE MID ATLANTIC STATES WILL COMBINE WITH HIGH PRESSURE OVER EASTERN CANADA. THIS WILL RESULT IN AN INCREASED PRESSURE GRADIENT WITH EASTERLY SCA WIND DEVELOPS DEVELOPING FRIDAY AND CONTINUING FRIDAY NIGHT ACROSS THE OPEN WATERS. OUTLOOK... SAT-MON...E/NE GALES LIKELY FROM TIME TO TIME. SEAS EVENTUALLY BUILD TO 16 TO 22 FT OUTER WATERS. LOW PROB STORM FORCE GUSTS SAT NIGHT AND EARLY SUN ASSOCD WITH THE LLJ AND AGAIN MONDAY AS THE ENVELOPE OF STRONG WINDS WHICH LIFTED N DURING SUNDAY COLLAPSES SEWD WITH THE DEPARTING STORM. MON NIGHT-TUE...SEAS SUBSIDE TO 8 TO 12 FT MON NIGHT AND TO 6 TO 10 FT OVER THE OUTER WATERS TUE. WINDS WILL FINALLY DIMINISH TO BELOW SMALL CRAFT ADVISORY LEVELS BY LATE TUE AFTERNOON. && .CLIMATE... 3/11/10 CLIBOS HAS MISSING WIND DATA SINCE 1026AM DATA OF 32 SUSTAINED AND GUST 76 MPH WAS INCORRECT. UNSURE OF THE SOURCE. ALSO...GHG DATA RTS TODAY ARD 22Z AND BUT THE DATA FOR 3/11 THERE WILL BE INCOMPLETE. && .EQUIPMENT... ETSS GUIDANCE ON THE KBOX WEB HAS NOT UPDATED FOR 2 DAYS...WE WILL CK THIS DURING THE DAYLIGHT HOURS FRIDAY BUT PLEASE DO NOT USE THIS. WE ARE INCREASING SURGE GUIDANCE BY AT LEAST HALF A FOOT THRU THE NEXT 4 DAYS DUE TO PDERSISTENT ONSHORE FLOW AND WE SHOULD HAVE A SURGE OF 2 FT OR MORE ON SUNDAY ALONG THE E MASS COAST. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...GALE WATCH FROM SATURDAY MORNING THROUGH SUNDAY MORNING FOR ANZ231>235-237-254>256. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST SATURDAY FOR ANZ231>235-237-250-251-254>256. GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING FOR ANZ230-236-250-251. && $$ SYNOPSIS...KJC NEAR TERM...STRAUSS SHORT TERM...FRANK LONG TERM...KJC/GAF AVIATION...FRANK/STRAUSS/GAF MARINE...KJC/FRANK/STRAUSS/GAF CLIMATE...1252A EQUIPMENT...1252 A WWWW