000
FXUS61 KBOX 071147
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
647 AM EST WED JAN 7 2009
.SYNOPSIS...
A WINTER STORM IS IMPACTING INTERIOR SOUTHERN NEW ENGLAND THROUGH
TONIGHT WITH A COMBINATION OF SNOW AND ICE. MAINLY DRY AND COLDER
WEATHER RETURNS FOR THE END OF THIS WEEK. MORE SNOW IS POSSIBLE SAT
AND SAT NIGHT AS A FAST MOVING CLIPPER TRACKS ALONG OR SOUTH OF THE
COAST. COLDER AND DRIER CONDITIONS SHOULD FOLLOW FOR SUNDAY WITH
ANOTHER STORM POSSIBLE MONDAY OR TUESDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
646 AM UPDATE: WIRES DOWN REPORTS FROM PARTS OF SE MASS TO THE UPPER
CAPE...MATTAPOISETT/BREWSTER WHERE ICING IS ABOUT OVER.
2 INCH SNOWFALL VCNTY TEMPLE/GROTON MASS. MAYNARD 1.4 INCHES.
LOGAN HAD 1.1 OVERNIGHT AND NOW ALL RAIN!
WE UPDATED THE GRIDS SLIGHTLY FOR THIS MORNING MAINLY N CT RI AND SE
MASS TO THE UPPER CAPE FOR LONGER DURATION OF FREEZING RAIN.
ALSO THINK WE ARE GENERATING SMALL FLAKE SNOW AND SLEET AOB 6000 FT
IN PARTS OF SNE ARD 6 AND 7AM DUE TO LOW LVL LIFT.
BELOW FROM EARLIER DISCUSSION.
LATEST OBSERVATIONS INDICATING WINTER STORM TODAY WILL PRODUCE MORE
ICE THAN SNOW OR SLEET...ESPECIALLY ACROSS INTERIOR SECTIONS. RISK OF
SOME POWER OUTAGES INCREASING ACROSS HIGHER TERRAIN OF HARTFORD
COUNTY...AS WELL AS THE WESTERN 2/3 OF MA AND SOUTHWEST NH.
SKYWARN ACTIVATION BEGINS AROUND 530 AM. SKYWARN PRESENCE WILL BE
HERE IN THE OFFICE FOR GLAZE AND POWER OUTAGE REPORTS. WE ARE USING
WEB REPORTS TOO.
THANKS TO ALL FOR YOUR ASSISTANCE. ACCURATE GLAZE THICKNESS REPORTS
ARE GOING TO BE EXCEEDINGLY HELPFUL. WOULD LIKE MEASUREMENTS ON
BRANCHES AND PAVEMENT IF POSSIBLE. ONCE WE SURPASS ONE QUARTER INCH
THICKNESS...INITIAL PROBLEMS BEGIN AND MAGNIFY GREATLY TOWARD ONE
HALF INCH.
A BRIEF RESPITE FROM THE HEAVIER FREEZING RAIN RATES EARLY THIS
MORNING...HOWEVER WILL BE FREEZING RAIN/DRIZZLE CONTINUING UNTIL THE
NEXT BATCH OF HEAVIER PRECIPITATION ARRIVES TOWARD MID MORNING.
ALONG AND N OF THE MASS PIKE SNOW SLEET AND FREEZING RAIN MIX... TO
GRADUALLY CHANGE TO MAINLY FREEZING RAIN BETWEEN 6 AM AND 9 AM.
MEANWHILE THE WARMING /ABOVE FREEZING/ IS PROGRESSING STEADILY NWWD
FROM THE CAPE AND THE ISLANDS WE MAY CANCEL THE FREEZING RAIN ADVISORY
EARLY ON CAPE COD.
07/06Z NAM STILL SHOWING -6C AT 09Z AROUND 925 MB FROM WEST HARTFORD
COUNTY NORTHWARD TO NEAR WESTFIELD MA...THEN EAST TO JUST NORTH OF
WORCESTER AND LAWRENCE. AT 12Z THE -6C IS ONLY ACROSS LITCHFIELD
COUNTY CT AND BERKSHIRE COUNTY MA INTO TO NORTHWEST CHESHIRE COUNTY NH.
THIS HELPS EXPLAIN REMAINING PL.
ICY THIS MORNING. PROBLEMS WITH MOS GUIDANCE TEMPERATURES BEING TOO
WARM...AND DID NOT USE THEM VERBATIM. UNTIL WE GET A DECENT EASTERLY
BOUNDARY LAYER WIND...MOS GUIDANCE WILL HAVE PROBLEMS WITH THE SHALLOW
COLD AIR.
ALSO...ITS OUR EXPERIENCE THAT KPSM MOS GUIDANCE CAN BE AN EFFECTIVE
TOOL FOR NORTHERN ESSEX COUNTY...AND EVEN SOMETIMES BOSTON.
BOTTOM LINE...THIS IS AN POTENTIALLY DANGEROUS MORNING DUE TO ICE.
FORESEE MANY TRAVEL DIFFICULTIES ON ALL UNTREATED SURFACES. AND EVEN
IF MAIN ROADS ARE TREATED...ITS TOUGHER TO SEE PATCHY ICE IN THE DARK.
ONE NOTE...POTENTIAL DAMAGE TODAY SHOULD END UP EXPANDING SWD SLIGHTLY
FROM EARLY DECEMBER. HOW DO WE COMPARE TO THAT EVENT... DONT HOLD ME
TO THIS 100 PCT BUT AS A HELPFUL PREDICTOR... IT SHOULD NOT BE QUITE
AS BAD AS EARLY DECEMBER..PROBABLY A BIT LESS QPF...BUT POTENTIAL
EXISTS FOR LENGTHY POWER OUTAGES PORTIONS OF W HFD COUNTY ACROSS W
2/3 RDS OF MASS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM THURSDAY/...
WORST OF THE ICING EXPECTED TO BE IN THE BDL-ORH-BED CORRIDOR WHERE
HEAVIER QPF AND LONGER DURATION OF FZRA EXPECTED. LESS ICE FURTHER
NORTH INTO NW MA AND SW NH WHERE MORE SLEET AND LESS QPF EXPECTED.
SREF PTYPE PROBS ALSO HIT THE CENTRAL INTERIOR ZONES HARDER THAN NW
ZONES FOR ICE.
QPF 12-00Z RANGING FROM 0.5" TO 1"+...BUT HEAVIER AMOUNTS EXPECTED
TO BE ACROSS THE COASTAL PLAIN.
SOUNDINGS SHOWING SOME DRYING IN THE LOW TO MID LEVELS THIS
AFTERNOON... WHICH MAY RESULT IN A LULL IN THE PRECIP.
IT APPEARS THE CORE OF THE LLJ WILL REMAIN JUST OFFSHORE...SO DO NOT
EXPECT VERY STRONG WINDS. BUT GUSTS TO 40 MPH NOT OUT OF THE QUESTION
FOR NANTUCKET.
AS COASTAL LOW MOVES NORTH OF OUR REGION TONIGHT...PRECIP WILL BECOME
MORE SHOWERY AND GRADUALLY TRANSITION BACK TO SNOW SHOWERS...MAINLY
ACROSS NORTHWEST MA AND SOUTHERN NH. AN ADDITIONAL 1 INCH
ACCUMULATION IS POSSIBLE. WEST WINDS WILL INCREASE LATE TONIGHT AS
WELL. SOME CONCERN ABOUT WHAT THESE INCREASED WINDS DOES TO REMAINING
GLAZED TREE LIMBS AND WIRES EARLY THURSDAY MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THURSDAY...HIGH PRESSURE STARTS TO BUILD INTO SOUTHERN NEW ENGLAND
BEHIND AN UPPER LEVEL TROUGH THAT MOVES THROUGH THE AREA. THERE MAY
BE A FEW LINGERING SNOW SHOWERS IN THE MORNING IN NORTHWESTERN
MASSACHUSETTS AND SOUTHWESTERN NEW HAMPSHIRE. OTHERWISE HIGHS WILL
BE IN THE MID TO UPPER 30S. SKIES CLEAR GRADUALLY OVERNIGHT
ALLOWING LOW TEMPERATURES TO DROP INTO THE TEENS TO THE LOWER 20S.
WINDS WILL BE GUSTY THROUGH THE DAY WITH GUSTS DIMINISHING
OVERNIGHT. THIS WILL RESULT IN WIND CHILLS IN THE SINGLE DIGITS
ACROSS THE INTERIOR.
FRIDAY...HIGH PRESSURE CONTINUES TO BUILD INTO THE AREA. QUIET
WEATHER BUT COLD DURING THE DAY WITH HIGHS IN THE 20S. WINDS WILL
NOT BE AS STRONG AS THURSDAY BUT EVEN THE 10 TO 15 KT WIND WILL BE
ENOUGH TO MAKE IT FEEL LIKE TEMPERATURES ARE ONLY IN THE SINGLE
DIGITS TO TEENS. OVERNIGHT...AS THE NEXT SYSTEM APPROACHES THE AREA
THE CHANCE OF SNOW WILL INCREASE. LOW TEMPERATURES WILL BE IN THE
SINGLE DIGITS TO TEENS.
SATURDAY...A SURFACE LOW PRESSURE SYSTEM WILL MOVE FROM THE GREAT
LAKES...ACROSS NEW YORK AND THEN EITHER ALONG THE SOUTH COAST OR A
BIT FURTHER SOUTH. AT THIS POINT...THE MINOR DISCREPANCY ON THE
TRACK BETWEEN THE MODELS DOES NOT HAVE MUCH OF AN EFFECT ON THE
SENSIBLE WEATHER. EITHER WAY...A SNOW STORM IS IN STORE FOR US ON
SATURDAY. ONCE THE CURRENT STORM IS OVER...MORE DETAILS WILL COME
ON THE SATURDAY STORM. AT THIS POINT...IT DOES LOOK LIKE A PLOWABLE
SNOW.
BEGINNING SUNDAY...THE MEDIUM RANGE TO LONG TERM MODELS DEVELOP
SOME FAIRLY SIGNIFICANT DIFFERENCES. BECAUSE OF THIS AND THE
CONTINUING ICE STORM...HAVE BLENDED THE LATEST GFS WITH THE PREVIOUS
FORECAST. GENERALLY SPEAKING...SUNDAY LOOKS QUIET WITH HIGH
PRESSURE FOR AT LEAST A PORTION OF THE DAY. THEN MONDAY AND
TUESDAY...ANOTHER LOW PRESSURE SYSTEM WILL MOVE INTO THE AREA.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
MVFR/IFR CONDITIONS IN FREEZING RAIN...SLEET AND SNOW. ICING THE
BIGGEST CONCERN TODAY. AIRPORT WEATHER WARNINGS IN EFFECT FOR KBOS
AND RI AIRPORTS THROUGH AT LEAST 730 AM DUE TO ICING. ICING ZONE WILL
SHIFT NORTHWEST THROUGH THIS MORNING.
NOW THE 06Z NAM HAS COME AROUND TO THE GFS SOLN IN THE LLJ AND SO WE
ADDED LLWS AT KACK PER 06Z NAM/GFS AGREEMENT!
PLEASE SEE BELOW FOR WHAT WERE THE DIFFERENCES IN THE 00Z/7 GFS/NAM
PREDICTION FOR KACK VIA BUFKIT.
00Z/7 GFS AND NAM WERE SO VASTLY DIFFERENT AT 18Z TODAY...
GFS NAM
1000 FT 51KT 10KT
2000 FT 67KT 38KT
IFR CONDITIONS ARE EXPECTED TO IMPROVE TO VFR TONIGHT AS LOW
PRESSURE MOVES AWAY FROM THE REGION.
PLEASE NOTE... VERY STRONG WSW WINDS WILL BE IN THE KACK KFMH AND
KHYA TERMINALS FOR THE 08Z TO 12Z TIME FRAME THURSDAY
IN THE UPCOMING 12Z TAF ISSUANCE!
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY...VFR. SW TO W SFC WIND GUSTS 25-35 KTS DURING THE DAY.
THURSDAY NIGHT AND FRIDAY...VFR. W SFC WIND GUSTS 20-30 KTS.
FRIDAY NIGHT...VFR DIMINISHING TO MVFR/IFR IN SNOW.
SATURDAY...MVFR/IFR CONDITIONS POSSIBLE IN SNOW.
SUNDAY...VFR.
&&
.MARINE...
TODAY...NORTHEAST WINDS INCREASE TO SMALL CRAFT ADVISORY LEVELS
TODAY...WITH A PERIOD OF EASTERLY GALES POSSIBLE SOUTH AND EAST OF
NANTUCKET. IT IS MARGINAL AND BRIEF...SO NO GALE WARNING POSTED FOR
TODAY. WILL NEED TO KEEP AN EYE ON THIS THOUGH.
A BREAK IN THE WIND EXPECTED LATE THIS AFTERNOON/EARLY THIS
EVENING...THEN WEST WINDS WILL INCREASE AS A COASTAL LOW MOVES NORTH.
ANOTHER PERIOD OF GALE FORCE WINDS EXPECTED TONIGHT. COULD EVEN SEE
STORM FORCE GUSTS...BUT CONFIDENCE NOT EVEN HIGH ENOUGH FOR A STORM
WATCH AT THIS POINT. WILL ISSUE A GALE WARNING FOR ALL WATERS EXCEPT
BOSTON HARBOR AND NARRAGANSETT BAY...WHERE A GALE WATCH IS IN EFFECT
INSTEAD.
OUTLOOK...THURSDAY THROUGH SUNDAY..
THURSDAY...SOUTHWESTERLY WINDS 25 TO 35KTS SHIFT TO WESTERLY IN THE
EVENING THEN NORTHWESTERLY NEAR DAWN. GUSTS 30 TO 45 KTS DURING THE
DAY DIMINISH TO 25 TO 30 KTS LATE THURSDAY NIGHT. A CHANCE OF LIGHT
FREEZING SPRAY OVERNIGHT. SEAS SLOWLY DIMINISH THURSDAY NIGHT.
FRIDAY...WESTERLY WINDS 20 TO 30 KTS. SEAS CONTINUE TO DIMINISH
SLOWLY. CHANCE OF LIGHT FREEZING SPRAY.
FRIDAY NIGHT...WESTERLY WINDS DIMINISH TO 10 TO 20 KTS. CHANCE OF
LIGHT FREEZING SPRAY. SEAS CONTINUE TO DIMINISH REMAINING AT OR
SLIGHTLY ABOVE 5 FT ON THE OUTER WATERS.
SATURDAY...WESTERLY WINDS 25 TO 30 KTS SHIFT BRIEFLY TO THE SOUTH IN
THE AFTERNOON AND THEN SHIFT BACK TO THE WEST. CHANCE OF LIGHT
FREEZING SPRAY OVERNIGHT. SEAS INCREASE AHEAD OF THE NEXT COLD
FRONT TO MOVE ACROSS THE COASTAL WATERS.
SUNDAY...SEAS GRADUALLY DIMINISH AS HIGH PRESSURE BUILDS INTO
SOUTHERN NEW ENGLAND. WESTERLY WINDS 25 TO 30 KTS WITH GUSTS TO
NEAR 40 KTS POSSIBLE. CHANCE OF LIGHT FREEZING SPRAY OVERNIGHT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
CTZ003-004.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR CTZ002.
MA...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR MAZ002>006-
026.
WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
MAZ017>022.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MAZ007-013>016.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MAZ008>012.
NH...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR NHZ011-012-
015.
RI...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
RIZ002>007.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
RIZ001.
MARINE...GALE WARNING FROM 1 AM THURSDAY TO MIDNIGHT EST THURSDAY NIGHT
FOR ANZ232>235-237-250-254-255.
GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR
ANZ230-236.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ230-
236.
GALE WARNING FROM 6 AM THURSDAY TO MIDNIGHT EST THURSDAY NIGHT
FOR ANZ231.
&&
$$
SYNOPSIS...KJC/DRAG/BELK
NEAR TERM...DRAG/BELK 647
SHORT TERM...BELK
LONG TERM...RLG
AVIATION...DRAG/RLG 647
MARINE...BELK/RLG
