FXUS61 KBOX 060220
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
920 PM EST SAT DEC 5 2009

.SYNOPSIS...
LOW PRESSURE OFF THE MID ATLANTIC COAST WILL MOVE RAPIDLY NORTHEAST
AND INTENSIFY DRAMATICALLY AS IT PASSES SOUTHEAST OF NANTUCKET TONIGHT.
THIS LOW WILL QUICKLY MOVE AWAY ON SUNDAY AND BE REPLACED BY HIGH 
PRESSURE THROUGH MONDAY. WEAK LOW PRESSURE MAY AFFECT SOUTHERN NEW
ENGLAND MONDAY NIGHT. ANOTHER FAST MOVING LARGE LOW PRESSURE SYSTEM
WILL IMPACT THE REGION MIDWEEK WITH A MIXTURE OF PRECIPITATION AND
WIND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
ADVISORIES PRETTY MUCH REMAIN AS IS THIS EVENING. ADDED COASTAL MASS
AND RI /EXCEPT THE CAPE AND ISLANDS/ TO THE WINTER WEATHER ADVISORY.
WHILE I DO NOT THINK THEY WILL AVERAGE 3 INCHES IN THESE
LOCATIONS...TEMPS WILL DROP TO AROUND 32 AND ROADS WILL BECOME QUITE
SLIPPERY OVERNIGHT...THEREFORE SINCE IT/S THE FIRST REAL WINTER
WEATHER EVENT OF THE SEASON...FELT LIKE THEY DESERVED TO BE IN THE
ADVISORY.

OTHERWISE...HEAVIEST SNOWFALL OF THE EVENT GENERALLY OCCURS BETWEEN
NOW /02Z/ AND 08Z. EVENING RADAR REFLECTIVITY IS BLOTCHY...WITH
PATCHES OF GOOD REFLECTIVITY WITH HOLES SHOWING UP FROM TIME TO TIME.
WOULD LIKE TO SEE RADAR IMAGERY SOLIDIFY MORE TO ALLOW FOR TRUE
WIDESPREAD ADVISORY SNOWS ON THE LOWER TERRAIN. NOT REAL SURE IF WE
GET A GOOD CCB GOING BEFORE THE SYSTEM MOVES AWAY YET. THE 00Z NAM
TRIES TO DO IT...BUT IT WILL BE CLOSE. IF THE 00Z NAM
VERIFIES...EASTERN PORTIONS WILL GET HIT PRETTY HARD AROUND 06Z WITH
20 MICROBARS UVV SMACK DAB IN THE SNOW GROWTH ZONE...1 INCH PER HOUR
SNOWS. WE/LL HAVE TO SEE HOW THINGS DEVELOP THROUGH MIDNIGHT. WHATEVER
HAPPENS...MAX ACCUMS WILL OCCUR ON GRASS...WITH LESSER AMOUNTS ON
ROADWAYS.

WINDS WILL CONTINUE TO BE AN ISSUE ON THE CAPE AND ISLANDS AS WELL AS
COASTAL PLYMOUTH COUNTY. LOW PROB OF HIGH WIND WARNING FOR 2 HOURS OR
SO AROUND 06Z. WILL CONTINUE TO MONITOR.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY...QUIETS DOWN WITH A NICE LOOK TO THE LANDSCAPE WITH FRESH
SNOW COVER. A BIT CHILLER THAN TODAY AND UNDERCUT MAV MOS GUIDANCE
WHICH MAY NOT BE HANDLING THE BL CHILL CORRECTLY AND ALSO NOT
ACCOUNTING FOR THE NEW SNOW COVER.  GUSTY WINDS FOR A TIME IN THE 
MORNING. RGEM SKYCOVER USED...SINCE IT HIGHLIGHTED BEST WHAT I
THOUGHT MIGHT BE A DELAYED CLEARING AT NANTUCKET.  THAT USE OF RGEM 
SKY MAY HAVE BEEN A MISTAKE IN RETROSPECT BUT FOR NOW IT IS OUR
GOING CLOUD COVER FCST.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE BUILDS SUNDAY NIGHT AND MONDAY BRINGING COOL BUT DRY 
WEATHER TO SOUTHERN NEW ENGLAND.  

MONDAY NIGHT...WEAK LOW PRESSURE MOVING ACROSS NORTHERN NEW ENGLAND 
MAY RESULT IN A PERIOD OF SHOWERS MOSTLY CONFINED TO SOUTHEAST 
MASSACHUSETTS AND THE CAPE AS WELL AS PORTIONS OF NORTHWEST MASS AND 
SOUTHWEST NH.  THERE IS SOME DISCREPANCY IN THE MODELS AS TO THE 
TRACK OF THIS STORM WITH BOTH THE 05/12Z NAM AND 05/00Z ECMWF MOVING 
THE LOW PRESSURE FROM THE GREAT LAKES ACROSS NORTHERN NEW ENGLAND 
AND THE 05/12Z GFS MOVING IT ACROSS THE GREAT LAKES AND MOVING IT 
FROM LAKE ONTARIO TO THE 40/70 BENCHMARK IN 6 HOURS.  WITH THE 
NAM/ECMWF SOLUTION A BIT MORE PLAUSIBLE...WILL GO WITH THAT 
SOLUTION.  PTYPE IN NW MA AND SW NH WILL LIKELY BE SNOW... 
HOWEVER...LITTLE IF ANY ACCUMULATION IS EXPECTED.  SOUTHEAST MASS 
AND THE CAPE WILL LIKELY BE RAIN WITH PERHAPS A LITTLE BIT OF SNOW 
MIXED IN TO START.

HIGH PRESSURE WILL MOVE ACROSS SOUTHERN NEW ENGLAND TUESDAY THEN THE 
NEXT LOW PRESSURE SYSTEM WILL AFFECT THE AREA WEDNESDAY INTO 
THURSDAY.  THERE IS SOME DISCREPANCY AMONGST THE MODELS AS TO THE 
TRACK OF THE SYSTEM.  WHILE BOTH THE ECMWF AND GFS DEVELOP SECONDARY 
LOWS ALONG THE COAST OFF THE PRIMARY ONE OVER THE GREAT LAKES... 
THERE ARE DIFFERENCES IN THE TIMING OF WHEN AND WHERE THEY MELD INTO 
ONE LOW AGAIN.  THE ECMWF PULLS THE SECONDARY LOW INTO THE STRONGER 
PRIMARY OVER THE GREAT LAKES WHEN THE SECONDARY IS OVER NEW JERSEY.  
THE GFS DOESN/T PULL THE SECONDARY IN UNTIL ITS MOVED ACROSS 
SOUTHERN NEW ENGLAND.  THESE DIFFERENCES WILL MAINLY AMOUNT TO 
TEMPERATURE DIFFERENCES AS PRECIPITATION IS A GIVEN NO MATTER THE 
TRACK.  WHILE THERE IS A DIFFERENCE IN TEMPERATURES BETWEEN THE 
MODELS IT IS NOT GREAT ENOUGH TO MAKE A DIFFERENCE IN PTYPE.  
TEMPERATURES BOTH AT THE SURFACE AND ALOFT WILL BE WARM ENOUGH FOR 
RAIN TO BE THE DOMINANT PRECIP TYPE THOUGH THERE MAY BE LIGHT SNOW 
TO START LATE TUESDAY NIGHT/EARLY WEDNESDAY MORNING AND TO END 
THURSDAY MORNING.

HAVE KEPT A SLIGHT CHANCE OF SNOW SHOWERS FOR NW PORTION OF CWA ON
THU NIGHT AS UPPER LEVEL SHORTWAVE MOVES OVER SNE AND THEN OUT OF THE
REGION. DECENT CAA TO FOLLOW...BRINGING COLDER TEMPERATURES AND DRY
WEATHER FOR THE END OF THE WEEK. MODELS ALSO INDICATING STRONG LOW
LEVEL WINDS...SO COULD SEE SOME GUSTY CONDITIONS THU NIGHT AND
FRIDAY.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE SEASONABLY COOL...AT 
TIMES A DEGREE OR TWO BELOW NORMAL.  WEDNESDAY...TEMPERATURES WILL 
BE ABOVE NORMAL BY ABOUT 5 DEGREES.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THROUGH THIS EVENING...MVFR CONDS CAPE COD AND THE ISLANDS DEGRADE
TO IFR TONIGHT WITH CIGS LOWERING TO IFR AND NLY GUSTS OF 30-40 KTS
DEVELOPING. ELSEWHERE IFR V LIFR IN SNOW OR R CHANGING TO SNOW. 

AFTER MIDNIGHT...ABRUPT CLEARING AND IMPROVING TO VFR FM W TO E LATE 
AT NIGHT NOT REACHING THE CAPE AND ISLANDS BEFORE 12Z. SNOW AT FMH
AND HYA NR OR AFTER MIDNIGHT.  

PLS SEE TAFS FOR DETAILS. 

SUNDAY...VFR EXCEPT POSSIBLE DELAY OF VFR CLEARING ON NANTUCKET
DURING THE MORNING. NW GUSTS 20-30 KTS IN THE MORNING DIMINISHING IN
THE AFTN.

OUTLOOK /SUNDAY NIGHT THROUGH THURSDAY/...

SUNDAY NIGHT AND MONDAY...VFR.

MONDAY NIGHT...MVFR POSSIBLE IN SCT -SHRA/-SHSN

TUESDAY...VFR.

WEDNESDAY...MVFR/IFR LIKELY IN WIDESPREAD RAIN.  GUSTY SFC WINDS.

THURSDAY...IMPROVING CONDITIONS TO VFR.  GUSTY SFC WINDS CONTINUE.

&&

.MARINE...
TONIGHT...HEADLINES CONTINUE AS POSTED THIS MORNING. GALES ALL WATERS
EXCEPT SCA BOS HARB AND NARR BAY. 

TOMORROW...CONVERSION OF GALE TO SCA ANTICIPATED. PLS SEE MWW FOR 
DETAILS.

OUTLOOK /SUNDAY NIGHT THROUGH THURSDAY/...

EXPECT LEFTOVER HAZARDOUS SEAS ON SUN NIGHT DIMINISHING BELOW 5 FT 
BY MONDAY MORNING.  EASTERLY WINDS SHIFT TO THE SE INCREASING 
TUESDAY NIGHT INTO WEDNESDAY LIKELY REQUIRING A GALE WARNING FOR THE 
COASTAL WATERS ON WED. W GALE LIKELY ON BACKSIDE OF SURFACE LOW FOR 
THU.

&&

.TIDES/COASTAL FLOODING...
NE TO N WIND COULD BRING A NEAR 1 FT URGE TO SANDWICH AND OTHER
NORTH AND NE FACING CAPE COD BAY SHORELINES LATE TONIGHT BUT EXPECT
ONLY SPLASHOVER AT WORST AS THE NIGHTTIME ASTRO TIDE IS NOT
ESPECIALLY HIGH. SHOULD BE LOSING ONSHORE FLOW COMPONENT OF WIND BY
THE TIME OF THE HIGHER SUN AFTERNOON ASTRO TIDE.

SPLASHOVER ANTICIPATED TONIGHTS 2 AM HIGH TIDE OTHER PARTS OF E MA
COAST.

&&

.EQUIPMENT...
GLOUCESTER NWR TRANSMITTER IS OFF THE AIR. RTS UNKNOWN. 
WE ARE WORKING ON THE PROBLEM. JOHNSTON/PROVIDENCE NWR TRANSMITTER
IS BACK ON THE AIR BUT ON LOW POWER...SOME SOUTH COASTAL LOCATIONS
MAY BE UNABLE TO RECEIVE THE SIGNAL. MORE MAINTENANCE WILL BE DONE ON
MONDAY TO RETURN THIS STATION TO FULL POWER. IN THE MEANTIME...PLEASE
SEE OUR WEBSITE... WWW.WEATHER.GOV/BOSTON FOR WEATHER INFORMATION.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 5 AM EST SUNDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 5 AM EST SUNDAY FOR MAZ002>004-
     008>012-026.
     WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR MAZ005>007-
     013>021.
     WIND ADVISORY UNTIL 7 AM EST SUNDAY FOR MAZ019-022>024.
NH...WINTER WEATHER ADVISORY UNTIL 5 AM EST SUNDAY FOR NHZ011-012-
     015.
RI...WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR RIZ001>007.
MARINE...GALE WARNING UNTIL 7 AM EST SUNDAY FOR ANZ230>237-250-251-
     254>256.

&&

$$
SYNOPSIS...DRAG
NEAR TERM...DRAG/EKSTER
SHORT TERM...EKSTER
LONG TERM...RLG/JFP
AVIATION...DRAG/EVT/RLG
MARINE...DRAG/RLG
TIDES/COASTAL FLOODING...
EQUIPMENT...