070 FXUS61 KBOX 160228 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1028 PM EDT WED MAY 15 2013 .SYNOPSIS... A COOL FRONT WILL MOVE THROUGH DURING THE NIGHT. DRY AND WARM WEATHER RETURNS FOR THURSDAY. A WEAK...DRY COLD FRONT WILL QUICKLY CROSS THE REGION THURSDAY NIGHT...BRINGING COOLER BUT SEASONABLE CONDITIONS FRIDAY INTO THE WEEKEND. A WARMING TREND IS LIKELY EARLY NEXT WEEK AS MARITIME HIGH PRESSURE MOVES OFFSHORE. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 1030 PM UPDATE... CONTINUED CLEARING AS ENERGY PUSHES EAST AND DRIER AIR BUILDS IN FROM THE WEST. MONITORING A DRY COLD FRONT ACROSS UPSTATE NEW YORK APPROACHING NEW ENGLAND. SUBSTAINTIAL MOISTURE COUPLED WITH FALLING TEMPERATURES POSES THE THREAT FOR AREAS OF DENSE FOG. BUT FOG FORMATION MAY BE HAMPERED SHOULD THE DRY COLD FRONT SLIDE ACROSS THE REGION PRIOR TO MORNING. A TRICKY FORECAST. SHOULD ANY DENSE FOG DEVELOP...EXPECT REDUCED VISIBILITIES THAT WILL MAKING DRIVING HAZARDOUS. MOTORISTS SHOULD BE AWARE OF THIS THREAT AND EXERCISE CAUTION BY TAKING IT SLOW WHERE APPROPRIATE. HIGH DEWPOINTS SIGNIFYING ABUNDANT MOISTURE AT THE SURFACE WILL KEEP LOWS MILD THIS EVENING WITH MID TO UPPER 40S ACROSS THE INTERIOR...LOW 50S ALONG THE SHORES. SOUTHERLY WINDS WILL BACK WESTERLY WITH PASSAGE OF THE COLD FRONT. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... THURSDAY... NEW ENGLAND REMAINS IN THE BASE OF A BROAD CYCLONIC UPPER FLOW AS H5 CUTOFF LOW SPINS OVER QUEBEC. EXPECT DRY CONDITIONS WITH W-SW WINDS IN PLACE. SKIES WILL BE MOSTLY CLEAR AND...ALONG WITH RATHER STRONG JET IN PLACE UP TO 700 HPA...WILL SEE EXCELLENT MIXING UP TO 700-800 HPA. W-SW WINDS WILL BE INCREASING...WITH GUSTS UP TO 35 MPH WITH SOME GUSTS UP TO 40 MPH AS TEMPS SOAR TO THE MID 70S TO AROUND 80. RELATIVE HUMIDITIES WILL BE RATHER LOW AS WELL...DOWN TO 20 TO 30 PERCENT...SO POTENTIAL FOR FIRE WEATHER CONCERNS /SEE FIRE WEATHER SECTION BELOW/. THURSDAY NIGHT... AS UPPER LOW MOVES E...WILL SEE WINDS DIMINISH AS TEMPS FALL BACK. EXPECT ANOTHER DRY FRONT TO MOVE ACROSS OVERNIGHT WITH LITTLE MORE THAN A WIND SHIFT TO NW-N. COOLER AIR WILL WORK IN AFTER MIDNIGHT AS H85 TEMPS FALL BACK TO +1 TO +4C. OVERNIGHT LOWS WILL FALL BACK TO THE 40S TO AROUND 50. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... BIG PICTURE... UPPER TROUGH OVER NEW ENGLAND MOVES OFF THROUGH THE MARITIMES BY SATURDAY. UPPER RIDGE THEN BUILDS OVER THE EASTERN USA FOR THE FIRST HALF OF NEXT WEEK. TREND TO A SLOWER MOVING PATTERN DURING NEXT WEEK. MODEL PREFERENCES...GENERAL AGREEMENT BETWEEN THE GFS AND ECMWF ON ON LARGE SCALE MASS FIELDS. DURING NEXT WEEK THE GFS IS MORE AGGRESSIVE IN BRINGING NORTHERN CANADA UPPER LOW SOUTH TO NEW ENGLAND...THE ECMWF GETS AROUND TO IT 24 HOURS LATER. WE USED A BLEND OF HPC AND GMOS GRIDS EXCEPT POPS WERE HAND DRAWN BASED ON ENSEMBLE COMPARISON OF THE VARIOUS MODEL QPF. THE DAILIES... FRIDAY...CYCLONIC FLOW ALOFT WITH COLD POOL PRESENT ALOFT. HOWEVER DESTABILIZING SHARP LAPSE RATES REMAIN ACROSS MAINE AND NORTHERN VT/NH. LIMITED MOISTURE 800-850 MB BUT MUCH DRIER ABOVE. SO WE EXPECT LIMITED DIURNAL CUMULUS BUT OTHERWISE A DRY DAY. MIXING DEPTHS REACH ABOVE 850 MB...POSSIBLY CLOSE TO 800 MB. WINDS THROUGH THIS LAYER WILL BE 15 KTS OR LESS. TEMPS IN THE LAYER WILL SUPPORT LOWER 70S...WITH A LITTLE DEEPER MIXING A FEW SPOTS COULD REACH MID 70S. SURFACE PRESSURE PATTERN IS SUFFICIENTLY LIGHT TO ALLOW MIDDAY/AFTERNOON SEABREEZES. SATURDAY-SUNDAY...HIGH PRESSURE BUILDS OVER THE REGION SATURDAY AND SHIFTS OFFSHORE SUNDAY. FAIR SKIES SATURDAY. FLOW TURNS SOUTHEAST SUNDAY WITH MODELS SHOWING MOISTURE INCREASING FROM THE SOUTH...SO MORE IN THE WAY OF CLOUDS ON SUNDAY BUT WITH DRY WEATHER. MONDAY THROUGH WEDNESDAY...UPPER RIDGE BREAKS DOWN DURING THIS PERIOD. HIGH PRESSURE OFFSHORE SHOULD KEEP US DRY MONDAY. THE GFS SWINGS A COLD FRONT THROUGH LATE TUESDAY FOLLOWED BY CANADIAN HIGH PRESSURE BUILDING SOUTH WITH DRY WEATHER WEDNESDAY. THE ECMWF BRINGS THE FRONT THROUGH ON WEDNESDAY. WE HAVE BROUGHT CHANCE POPS TO MOST OF THE REGION TUESDAY NIGHT AND WEDNESDAY. WHETHER THE SLOWER OR FASTER SCENARIO OCCURS...WE EXPECT A WARMING TREND THROUGH THE FIRST HALF OF THE WEEK WITH COOLING TEMPS AFTER THE COLD FRONT MOVES THROUGH. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... 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. 3Z UPDATE... THERE IS A POTENTIAL FOG THREAT THIS EVENING WITH IFR-VLIFR VSBYS POSSIBLE. WITH ANY DENSE FOG...ANTICIPATE CIGS WITH VV002. A COLD FRONT WILL APPROACH THE TERMINALS TOWARDS MORNING WITH DRIER AIR. WINDS WILL SHIFT OUT OF THE WEST WITH PASSAGE AND BECOME BLUSTERY DURING THE DAY THURSDAY WITH GUSTS UP TO AROUND 30 KTS /HIGHER GUSTS OF 35 KTS NOT OUT OF THE QUESTION/. WINDS DIMINISHING INTO THURSDAY NIGHT...REMAINING VFR. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK...FRIDAY THROUGH MONDAY... GENERALLY VFR DURING THE PERIOD. LOCAL IFR IN AREAS OF LATE NIGHT/MORNING FOG. && .MARINE... 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. TONIGHT...S-SW WINDS GUSTING UP TO 25 TO 30 KT EARLY WILL DIMINISH AS THEY VEER TO W OVERNIGHT AS THE COLD FRONT PASSES. SEAS WILL REMAIN AOA 5 FT. THURSDAY...W WINDS WILL NOT BE QUITE AS STRONG ACROSS THE WATERS AS BEST MIXING WILL OCCUR AWAY FROM THE COAST. WILL SEE GUSTS UP TO 20 KT...BUT SEAS WILL REMAIN AOA 5 FT. THURSDAY NIGHT...W WINDS WILL SHIFT TO N-NW AS ANOTHER COLD FRONT MOVES THROUGH...AND WILL START TO PICK UP LATE WITH GUSTS UP TO 20 KT. SEAS CONTINUE AOA 5 FT. OUTLOOK...FRIDAY THROUGH MONDAY... FRIDAY THROUGH MONDAY...WINDS BELOW 25 KNOTS THROUGH THE PERIOD. SEAS BELOW 5 FEET FRIDAY THROUGH SUNDAY...THEN 5 FOOT SEAS RETURN TO THE EXPOSED SOUTHERN WATERS ON MONDAY. && .FIRE WEATHER... THURSDAY...EXPECT MINIMUM RH VALUES IN THE 20 TO 30 PERCENT RANGE. WILL SEE EXCELLENT MIXING...POSSIBLY FROM 700 TO 750 HPA LEVEL /AROUND 9KFT/. THIS...ALONG WITH TEMPS SOARING TO THE MID 70S TO AROUND 80...W-SW WIND GUSTS WILL APPROACH 30-35 KT ESPECIALLY NEAR AND N OF THE MASS PIKE FROM LATE MORNING THROUGH MID TO LATE AFTERNOON. THE REGION IS CLOSE TO GREEN UP...EXPECT FOR HIGHER TERRAIN OF N MA AND ACROSS S NH. AT THIS POINT...WILL CONTINUE TO MONITOR BUT MAY NEED AT LEAST A SPECIAL WEATHER STATEMENT FOR ENHANCED FIRE WEATHER CONDITIONS ESPECIALLY ACROSS INLAND AREAS OF CENTRAL AND WESTERN MASS INTO S NH. MINIMUM RELATIVE HUMIDITY FRIDAY AND SATURDAY WILL BE 25 TO 40 PERCENT...BUT WITH WINDS BELOW 20 KNOTS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ231>234- 251. SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ230- 236. SMALL CRAFT ADVISORY UNTIL 5 AM EDT FRIDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ250-254>256. && $$ SYNOPSIS...WTB/EVT NEAR TERM...SIPPRELL SHORT TERM...EVT LONG TERM...WTB AVIATION...WTB/EVT MARINE...WTB/EVT FIRE WEATHER...STAFF