000 
FXUS61 KBOX 080601
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
101 AM EST SUN DEC 8 2013

.SYNOPSIS...
LARGE HIGH PRESSURE WILL SETTLE OVER NEW ENGLAND TONIGHT AND
SUNDAY. ANOTHER LOW PRES MOVING UP FROM THE SOUTH WILL BRING A
WINTRY MIX OF PRECIPITATION LATE SUN NIGHT INTO MON. THERE IS A
LOW PROBABILITY THAT SOME WINTRY PRECIP COULD AFFECT SOUTHERN
SECTIONS OF THE REGION TUE AFTERNOON/NIGHT WITH A SECOND LOW
PRESSURE SYSTEM. OTHERWISE...DRY AND UNSEASONABLY COLD WEATHER IS
EXPECTED NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1 AM UPDATE... 
HIGH CLOUDS CONTINUE TO STREAM INTO SNE...AND SOME LAKE EFFECT
STRATO CU SPILLING INTO THE BERKSHIRES. CANT RULE OUT A FEW
FLURRIES IN THE BERKSHIRES NEXT FEW HOURS PER LATEST RADAR...THEN
EXPECT LOWER CLOUDS TO ERODE AS SFC HIGH MOVES INTO THE REGION AND
DRYING OCCURS IN THE LOW LEVELS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
*/SUNDAY...

SURFACE HIGH PRESSURE SHIFTS NORTH AND EAST AS ITS CONTINUED 
INFLUENCE KEEPS THE REGION DRY /ABUNDANCE OF SUBSIDENCE AND LOW-
LEVEL DRY AIR IN PLACE/. WILL SEE RETURN EASTERLY FLOW LATE ALONG 
WITH INCREASING MID- TO HIGH-LEVEL CLOUDS THROUGHOUT THE DAY. HIGHS 
AROUND THE LOW-30S ACROSS THE INTERIOR...WITH MID-30S ALONG THE 
SHORES /COOLER THAN TODAY DUE TO THE EXPECTATION OF MOSTLY CLOUDY 
CONDITIONS/.

*/SUNDAY NIGHT INTO MONDAY...

DEEPER LOW AND ATTENDANT TROUGH ACROSS THE NORTHERN GREAT LAKES 
INTERACTS WITH THE BROADER SUB-TROPICAL FLOW AND THERMAL GRADIENT 
ACROSS THE SOUTHERN CONUS INVOKING A COASTAL LOW WITHIN THE 40N/70W 
BENCHMARK FOR THE TIMEFRAME. WHILE A GENERAL MODEL COMPROMISE IS 
PREFERRED...HAVE GREATER CONFIDENCE WITH COOLER SOLUTIONS OF THE 
07.12Z ECMWF/NAM. UNCERTAINTY THOUGH STILL PREVAILS WITH REGARDS TO 
THE EXACT LOCATION OF THE COASTAL LOW WITHIN THE BENCHMARK...AS WELL 
AS THERMAL PROFILES. WILL DISCUSS POINTS WITH GREATER CONFIDENCE 
BELOW. 

THE SITUATION IS COMPLICATED. LOW- TO MID-LEVEL WARM AIR FETCH IS 
PREVALENT TOWARDS THE STRONGER LOW OVER THE GREAT LAKES REGION. H925-
850 FLOW IS MAINLY SOUTH-SOUTHEASTERLY. A CONSISTENT PATTERN IS SEEN 
AMONG THE GUIDANCE OF RISING THICKNESSES OVER TIME /KEYING ON 1000-
850/ WITH A DECENT WARM NOSE WITHIN THE SOUNDINGS AROUND H8 OF +4C. 
MEANWHILE LOW-LEVEL AGEOSTROPHIC FLOW /MAINLY AT H975/ IS FROM THE 
NORTHERLY INTERIOR INDICATING COLD-AIR DAMMING PROCESSES ARE LIKELY 
TO BE ONGOING AT THE SURFACE. WORTHY OF NOTE...H950 AGEOSTROPHIC 
FLOW WAS MORE EASTERLY OFF THE MARITIMES...SO EXPECTING SHALLOW COLD 
AIR TO BE JAMMED UP IN VALLEYS. LIKELY TO SEE DRAINAGE FLOW THROUGH 
THE CONNECTICUT VALLEY /HAVE MODIFIED WIND GRIDS NORTHERLY AND 
DROPPED SURFACE TEMPS A DEGREE OR TWO TO ACCOUNT FOR THE DRAINAGE/. 
AN ATMOSPHERIC PROFILE INDICATING SLEET AND/OR FREEZING RAIN IS 
DERIVED. 

MORE ASTONISHINGLY...THERE ARE STRONG INDICATIONS OF LITTLE TO NO 
ICE WITHIN THE -12 TO -18C LAYER. THERE ARE SOME HINTS OF SEEDER-
FEEDER PROCESSES...AND THERE IS ALWAYS THE PLAUSIBILITY OF CLOUD-
CONDENSATION-NUCLEI /CCN/ OFF THE OCEAN...SO SNOW REMAINS POSSIBLE. 
BUT GREATER WEIGHT CONCERNING OUTCOMES IS GIVEN TOWARDS A WINTRY MIX 
OF SLEET AND/OR FREEZING RAIN. 

EVALUATING LIFT...THERE APPEARS LITTLE IN THE WAY OF JET DYNAMICS 
/RIGHT-EXIT REGION OF THE UPPER-LEVEL JET/ AND DEEP-LAYER ASCENT 
/WEAK DISTURBANCE ALOFT AND NO JET COUPLING WITH SURFACE FEATURES/. 
IT APPEARS MUCH OF THE FORCING IS PER ISENTROPIC LIFT AND LOW- TO 
MID-LEVEL CONVERGENCE AGAINST THE LINGERING COLD AIR DOME ASSOCIATED 
WITH THE DEPARTING HIGH PRESSURE. WHILE CONSIDERING PWATS UP TO 1 
INCH ACROSS THE SOUTH-SHORE...BELIEVE THERE ONLY TO BE STORM-TOTAL 
LIQUID PRECIPITATION TOTALS OF AROUND HALF AN INCH...THE GREATER OF 
WHICH MAY REMAIN OFFSHORE. HEIGHT FALLS DO NOT LOOK TREMENDOUS AND 
THE SURFACE LOW PRESSURE OF THE CENTER IS RATHER WEAK. 

WILL HOLD OFF FOR NOW ON THE ISSUANCE OF ANY HEADLINES...ALLOWING 
THE OVERNIGHT SHIFT TO LOOK OVER THE FORECAST AS THERE HAS BEEN A 
SIGNIFICANT SHIFT IN FORECAST ANALYSIS. WILL HIGHLIGHT THREATS AND 
IMPACTS WITHIN THE HAZARDOUS WEATHER OUTLOOK /HWO/. 

TIMING... 

SNOW-SLEET MIX SUNDAY NIGHT...TRANSITIONING TO SLEET-FREEZING RAIN 
SOUTH OF THE MASS-PIKE BY MONDAY MORNING...TO THE NH/MA BORDER BY 
MID-MORNING. RAIN-FREEZING RAIN LINE ALONG THE MASS-PIKE BY MID-
MORNING AND TO THE NH/MA BORDER BY MIDDAY. INTO THE AFTERNOON MUCH 
OF THE REGION SHOULD BE RAIN. COLD AIR ENTRENCHED IN INTERIOR 
VALLEYS PER COLD-AIR PROCESSES MAY RESULT IN THE WINTRY MIX TO 
LINGER-LONGER. THE BULK OF THE STORM WILL BE EARLY MORNING INTO 
MIDDAY MONDAY...SO EXPECT MUCH OF THE PRECIPITATION TO BE IN A FORM 
OF A WINTRY MIX IMPACTING THE MORNING COMMUTE. 

TOTALS...

HAVE LOWERED SNOW TOTALS FROM THE PREVIOUS SHIFT EXPECTING MAINLY 
SLEET AND FREEZING RAIN. HOLDING AT 1-2 INCHES FOR AREAS AWAY FROM 
THE COASTAL PLAIN WITH THE HIGHEST AMOUNTS ACROSS THE INTERIOR NORTH 
AND WEST /NORTH AND WEST MA AND SOUTHERN NH/. ICE IS THE BIGGER 
CONCERN...HAVE HAVE SEVERAL HUNDREDTHS OVER THE CENTRAL AND WESTERN 
INTERIOR...AWAY FROM THE EASTERN COASTAL PLAIN WITH THE ONSHORE 
FLOW. 

IMPACTS...

SNOW AND SLEET EXPECTED DURING THE MORNING COMMUTE WILL MAKE FOR 
HAZARDOUS DRIVING CONDITIONS. EXPECT REDUCED VISIBILITIES ALONG 
ROADWAYS...AS ACCUMULATIONS OF 1-2 INCHES WILL MAKE TRAVELING 
CONDITIONS SLIPPERY ALONG UNTREATED SURFACES AND ROADWAYS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

*HIGH PRESSURE SYSTEM RESIDES IN SOUTHERN UNITED STATES
*COLD COMES IN BEHIND FRONT ON WEDNESDAY
* WEAK SHORTWAVES COME INTO SOUTHERN NEW ENGLAND FROM CANADA

MODEL SPREAD IS QUITE HIGH FOR THIS TIME FRAME AS THE 12Z GFS SEEMS 
TO BE IN THE MIDDLE OF THE 12Z NAM AND THE 00Z ECMWF SUCH THAT IT 
HAS THE UPPER LEVEL JET IN A SIMILAR SPOT AS THE 12Z NAM WHEREAS THE 
00Z ECMWF HAS IT FURTHER SOUTH FOR TUESDAY NIGHT. THIS PLACEMENT MAY 
HELP TO ENHANCE WHAT THE 12Z NAM AND 12Z GFS BRING CLOSER TO 
SOUTHERN NEW ENGLAND THAN THE ECMWF IN A WAVE ALONG THE FRONT. THE 
NAM/SREF HAS BEEN THE ONLY MODEL SUITE THAT BRINGS THE PRECIPITATION 
FURTHER INLAND. THE GFS/GEFS KEEPS IT FURTHER SOUTH AND EAST SO THAT 
ONLY THE SOUTHERN COAST OF MA/RI/CT INCLUDING THE CAPE RECEIVE 
PRECIPITATION. ALL HAVE THEIR OWN ENSEMBLE BACKING. AT THIS POINT 
WILL RELY MAINLY ON THE GFS AS IT IS THE MIDDLE MODEL. IT DOES BEAR 
WATCHING AS POSSIBLE NORTHERN AND WESTERN SIDE OF THE WAVE COULD END 
UP WITH WINTRY PRECIP FOR A FEW HOURS. 

MEANWHILE...LATER IN THE WEEK...UPPER LEVEL LOW IN CANADA CONTINUES 
TO MOVE SLOWLY TO THE EAST BRINGING ITS ENERGY WITH IT. FLOW ENTERS 
THE REGION FROM THE NORTHWEST ON THURSDAY CARRYING WITH IT A HIGH 
PRESSURE SYSTEM FROM CANADA AND ITS ANTECEDENT COLD AIR.

DETAILS...

TUESDAY THROUGH WEDNESDAY...MODELS SEEM TO BE HAVING PROBLEMS 
RESOLVING A WAVE TRACKING UP THE STATIONARY FRONT DURING THIS TIME 
PERIOD WITH SPREAD EXPLAINED ABOVE. THE PLACEMENT OF THE JET IS 
IMPORTANT HERE BECAUSE A MORE NORTHERN PLACEMENT OF THE JET WOULD 
HAVE BETTER JET ENHANCEMENT FROM THE RIGHT REAR ENTRANCE REGION 
ALLUDING TO A MORE DEVELOPED LOW AND PRECIP THAT MOVES FURTHER 
INLAND FOR TUESDAY NIGHT. HAVE GONE WITH THE GFS FORECAST AT THIS 
POINT TO HIGHLIGHT POSSIBILITY OF PRECIP MOVEMENT NORTH INTO SOUTH 
COAST OF SOUTHERN NEW ENGLAND. WINTRY PRECIPITATION MAY RESULT FROM 
THIS WAVE ESPECIALLY ON THE NORTHERN AND WESTERN SIDE OF IT.

THURSDAY THROUGH SATURDAY...COLD FRONT MOVES OFFSHORE WITH COLD AIR 
MOVING BEHIND IT. HIGH PRESSURE COMES INTO THE REGION FROM THE SOUTH 
HOLDING COLD AIR AT BAY FOR A LITTLE WHILE. STILL HAVE PHASED UPPER 
LEVEL WINDS CARRYING MOST ENERGY OFFSHORE BEFORE IT CAN DEVELOP. FEW 
ALBERTA CLIPPERS COME IN FROM CANADA DURING THIS PERIOD AFTER THE 
FIRST HIGH PRESSURE SYSTEM MOVES OUT TO SEA. THE CLIPPERS WILL LACK 
PRECIPITATION.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT. 
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

NEAR-TERM /THROUGH MONDAY/...OVERALL HIGH CONFIDENCE. BUT LOWER
CONFIDENCE ON PTYPE TRANSITION LATE TONIGHT INTO MONDAY. 

VFR THROUGH TODAY WITH GRADUALLY LOWERING CIGS. DETERIORATING
CONDITIONS LATE TONIGHT THROUGH MONDAY WITH CIGS LOWERING TO
MVFR/IFR AS WINTRY MIX DEVELOPS. PTYPE STARTS AS SNOW EVERYWHERE
THEN TRANSITIONS TO SLEET/FZRA THEN RAIN NEAR THE COAST BY
DAYBREAK MON MORNING...WITH TRANSITION OCCURRING LATE MORNING
INTO THE AFTERNOON FURTHER IN THE INTERIOR.

KBOS TAF...HIGH CONFIDENCE IN TRENDS. TIMING OF ONSET OF SNOW
LATE TONIGHT COULD BE OFF A FEW HOURS.

KBDL TAF...HIGH CONFIDENCE IN TRENDS. TIMING OF ONSET OF SNOW
LATE TONIGHT AND TRANSITION TO SLEET COULD BE OFF A FEW HOURS.

OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...

MONDAY NIGHT AND TUESDAY MORNING...MODERATE TO HIGH CONFIDENCE IN 
MAINLY VFR CONDITIONS.

TUESDAY AFTERNOON AND NIGHT...LOW CONFIDENCE.  A PERIOD OF MVFR-IFR 
CONDITIONS CAN/T BE RULED OUT ACROSS OUR SOUTHERN ZONES IN A PERIOD 
OF SOME MIXED PRECIP/SNOW IF LOW PRESSURE GETS CLOSE ENOUGH.

WEDNESDAY AND THURSDAY...MODERATE TO HIGH CONFIDENCE IN VFR 
CONDITIONS DOMINATING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT. 
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

TONIGHT AND SUNDAY...HIGH CONFIDENCE. 

LEFT OVER SCA SEAS WILL LINGER ACROSS THE OUTER ATLANTIC WATERS
INTO SUN MORNING BEFORE DIMINISHING. NORTHWEST WIND GUSTS TO NEAR
20 KNOTS WILL CONTINUE TO DIMINISH OVERNIGHT AS PRESSURE BUILDS
IN FROM THE WEST.

SUNDAY NIGHT AND MONDAY...HIGH CONFIDENCE.  

WAVE OF LOW PRESSURE WORKING UP FROM THE SOUTH WILL RESULT IN
EASTERLY SCA WINDS GUSTS VERY LATE SUN NIGHT INTO MONDAY. GIVEN
ITS A LATE 3RD AND 4TH PERIOD EVENT WILL LET THE NEXT SHIFT HANDLE
THE MARINE HEADLINES.

OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...

MONDAY NIGHT AND TUESDAY...MODERATE TO HIGH CONFIDENCE.  

A COLD FRONT MOVES THROUGH THE REGION MONDAY NIGHT. THIS WILL
BRING WESTERLY SCA WIND GUSTS MON NIGHT INTO TUE IN THE COLD AIR
ADVECTION PATTERN.

TUESDAY NIGHT AND THURSDAY...MODERATE TO HIGH CONFIDENCE.  

CONTINUED COLD ADVECTION WILL RESULT IN AN EXTENDED PERIOD OF SCA
WIND GUSTS. MAY EVEN SEE A BRIEF PERIOD OF LOW END GALES LATE TUE
NIGHT INTO WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ250-254-255.

&&

$$
SYNOPSIS...FRANK/SIPPRELL/99
NEAR TERM...KJC
SHORT TERM...SIPPRELL
LONG TERM...99
AVIATION...KJC/FRANK
MARINE...KJC/FRANK/SIPPRELL/99

000 
FXUS61 KBOX 080601
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
101 AM EST SUN DEC 8 2013

.SYNOPSIS...
LARGE HIGH PRESSURE WILL SETTLE OVER NEW ENGLAND TONIGHT AND
SUNDAY. ANOTHER LOW PRES MOVING UP FROM THE SOUTH WILL BRING A
WINTRY MIX OF PRECIPITATION LATE SUN NIGHT INTO MON. THERE IS A
LOW PROBABILITY THAT SOME WINTRY PRECIP COULD AFFECT SOUTHERN
SECTIONS OF THE REGION TUE AFTERNOON/NIGHT WITH A SECOND LOW
PRESSURE SYSTEM. OTHERWISE...DRY AND UNSEASONABLY COLD WEATHER IS
EXPECTED NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1 AM UPDATE... 
HIGH CLOUDS CONTINUE TO STREAM INTO SNE...AND SOME LAKE EFFECT
STRATO CU SPILLING INTO THE BERKSHIRES. CANT RULE OUT A FEW
FLURRIES IN THE BERKSHIRES NEXT FEW HOURS PER LATEST RADAR...THEN
EXPECT LOWER CLOUDS TO ERODE AS SFC HIGH MOVES INTO THE REGION AND
DRYING OCCURS IN THE LOW LEVELS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
*/SUNDAY...

SURFACE HIGH PRESSURE SHIFTS NORTH AND EAST AS ITS CONTINUED 
INFLUENCE KEEPS THE REGION DRY /ABUNDANCE OF SUBSIDENCE AND LOW-
LEVEL DRY AIR IN PLACE/. WILL SEE RETURN EASTERLY FLOW LATE ALONG 
WITH INCREASING MID- TO HIGH-LEVEL CLOUDS THROUGHOUT THE DAY. HIGHS 
AROUND THE LOW-30S ACROSS THE INTERIOR...WITH MID-30S ALONG THE 
SHORES /COOLER THAN TODAY DUE TO THE EXPECTATION OF MOSTLY CLOUDY 
CONDITIONS/.

*/SUNDAY NIGHT INTO MONDAY...

DEEPER LOW AND ATTENDANT TROUGH ACROSS THE NORTHERN GREAT LAKES 
INTERACTS WITH THE BROADER SUB-TROPICAL FLOW AND THERMAL GRADIENT 
ACROSS THE SOUTHERN CONUS INVOKING A COASTAL LOW WITHIN THE 40N/70W 
BENCHMARK FOR THE TIMEFRAME. WHILE A GENERAL MODEL COMPROMISE IS 
PREFERRED...HAVE GREATER CONFIDENCE WITH COOLER SOLUTIONS OF THE 
07.12Z ECMWF/NAM. UNCERTAINTY THOUGH STILL PREVAILS WITH REGARDS TO 
THE EXACT LOCATION OF THE COASTAL LOW WITHIN THE BENCHMARK...AS WELL 
AS THERMAL PROFILES. WILL DISCUSS POINTS WITH GREATER CONFIDENCE 
BELOW. 

THE SITUATION IS COMPLICATED. LOW- TO MID-LEVEL WARM AIR FETCH IS 
PREVALENT TOWARDS THE STRONGER LOW OVER THE GREAT LAKES REGION. H925-
850 FLOW IS MAINLY SOUTH-SOUTHEASTERLY. A CONSISTENT PATTERN IS SEEN 
AMONG THE GUIDANCE OF RISING THICKNESSES OVER TIME /KEYING ON 1000-
850/ WITH A DECENT WARM NOSE WITHIN THE SOUNDINGS AROUND H8 OF +4C. 
MEANWHILE LOW-LEVEL AGEOSTROPHIC FLOW /MAINLY AT H975/ IS FROM THE 
NORTHERLY INTERIOR INDICATING COLD-AIR DAMMING PROCESSES ARE LIKELY 
TO BE ONGOING AT THE SURFACE. WORTHY OF NOTE...H950 AGEOSTROPHIC 
FLOW WAS MORE EASTERLY OFF THE MARITIMES...SO EXPECTING SHALLOW COLD 
AIR TO BE JAMMED UP IN VALLEYS. LIKELY TO SEE DRAINAGE FLOW THROUGH 
THE CONNECTICUT VALLEY /HAVE MODIFIED WIND GRIDS NORTHERLY AND 
DROPPED SURFACE TEMPS A DEGREE OR TWO TO ACCOUNT FOR THE DRAINAGE/. 
AN ATMOSPHERIC PROFILE INDICATING SLEET AND/OR FREEZING RAIN IS 
DERIVED. 

MORE ASTONISHINGLY...THERE ARE STRONG INDICATIONS OF LITTLE TO NO 
ICE WITHIN THE -12 TO -18C LAYER. THERE ARE SOME HINTS OF SEEDER-
FEEDER PROCESSES...AND THERE IS ALWAYS THE PLAUSIBILITY OF CLOUD-
CONDENSATION-NUCLEI /CCN/ OFF THE OCEAN...SO SNOW REMAINS POSSIBLE. 
BUT GREATER WEIGHT CONCERNING OUTCOMES IS GIVEN TOWARDS A WINTRY MIX 
OF SLEET AND/OR FREEZING RAIN. 

EVALUATING LIFT...THERE APPEARS LITTLE IN THE WAY OF JET DYNAMICS 
/RIGHT-EXIT REGION OF THE UPPER-LEVEL JET/ AND DEEP-LAYER ASCENT 
/WEAK DISTURBANCE ALOFT AND NO JET COUPLING WITH SURFACE FEATURES/. 
IT APPEARS MUCH OF THE FORCING IS PER ISENTROPIC LIFT AND LOW- TO 
MID-LEVEL CONVERGENCE AGAINST THE LINGERING COLD AIR DOME ASSOCIATED 
WITH THE DEPARTING HIGH PRESSURE. WHILE CONSIDERING PWATS UP TO 1 
INCH ACROSS THE SOUTH-SHORE...BELIEVE THERE ONLY TO BE STORM-TOTAL 
LIQUID PRECIPITATION TOTALS OF AROUND HALF AN INCH...THE GREATER OF 
WHICH MAY REMAIN OFFSHORE. HEIGHT FALLS DO NOT LOOK TREMENDOUS AND 
THE SURFACE LOW PRESSURE OF THE CENTER IS RATHER WEAK. 

WILL HOLD OFF FOR NOW ON THE ISSUANCE OF ANY HEADLINES...ALLOWING 
THE OVERNIGHT SHIFT TO LOOK OVER THE FORECAST AS THERE HAS BEEN A 
SIGNIFICANT SHIFT IN FORECAST ANALYSIS. WILL HIGHLIGHT THREATS AND 
IMPACTS WITHIN THE HAZARDOUS WEATHER OUTLOOK /HWO/. 

TIMING... 

SNOW-SLEET MIX SUNDAY NIGHT...TRANSITIONING TO SLEET-FREEZING RAIN 
SOUTH OF THE MASS-PIKE BY MONDAY MORNING...TO THE NH/MA BORDER BY 
MID-MORNING. RAIN-FREEZING RAIN LINE ALONG THE MASS-PIKE BY MID-
MORNING AND TO THE NH/MA BORDER BY MIDDAY. INTO THE AFTERNOON MUCH 
OF THE REGION SHOULD BE RAIN. COLD AIR ENTRENCHED IN INTERIOR 
VALLEYS PER COLD-AIR PROCESSES MAY RESULT IN THE WINTRY MIX TO 
LINGER-LONGER. THE BULK OF THE STORM WILL BE EARLY MORNING INTO 
MIDDAY MONDAY...SO EXPECT MUCH OF THE PRECIPITATION TO BE IN A FORM 
OF A WINTRY MIX IMPACTING THE MORNING COMMUTE. 

TOTALS...

HAVE LOWERED SNOW TOTALS FROM THE PREVIOUS SHIFT EXPECTING MAINLY 
SLEET AND FREEZING RAIN. HOLDING AT 1-2 INCHES FOR AREAS AWAY FROM 
THE COASTAL PLAIN WITH THE HIGHEST AMOUNTS ACROSS THE INTERIOR NORTH 
AND WEST /NORTH AND WEST MA AND SOUTHERN NH/. ICE IS THE BIGGER 
CONCERN...HAVE HAVE SEVERAL HUNDREDTHS OVER THE CENTRAL AND WESTERN 
INTERIOR...AWAY FROM THE EASTERN COASTAL PLAIN WITH THE ONSHORE 
FLOW. 

IMPACTS...

SNOW AND SLEET EXPECTED DURING THE MORNING COMMUTE WILL MAKE FOR 
HAZARDOUS DRIVING CONDITIONS. EXPECT REDUCED VISIBILITIES ALONG 
ROADWAYS...AS ACCUMULATIONS OF 1-2 INCHES WILL MAKE TRAVELING 
CONDITIONS SLIPPERY ALONG UNTREATED SURFACES AND ROADWAYS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

*	HIGH PRESSURE SYSTEM RESIDES IN SOUTHERN UNITED STATES
*	COLD COMES IN BEHIND FRONT ON WEDNESDAY
* 	WEAK SHORTWAVES COME INTO SOUTHERN NEW ENGLAND FROM CANADA

MODEL SPREAD IS QUITE HIGH FOR THIS TIME FRAME AS THE 12Z GFS SEEMS 
TO BE IN THE MIDDLE OF THE 12Z NAM AND THE 00Z ECMWF SUCH THAT IT 
HAS THE UPPER LEVEL JET IN A SIMILAR SPOT AS THE 12Z NAM WHEREAS THE 
00Z ECMWF HAS IT FURTHER SOUTH FOR TUESDAY NIGHT. THIS PLACEMENT MAY 
HELP TO ENHANCE WHAT THE 12Z NAM AND 12Z GFS BRING CLOSER TO 
SOUTHERN NEW ENGLAND THAN THE ECMWF IN A WAVE ALONG THE FRONT. THE 
NAM/SREF HAS BEEN THE ONLY MODEL SUITE THAT BRINGS THE PRECIPITATION 
FURTHER INLAND. THE GFS/GEFS KEEPS IT FURTHER SOUTH AND EAST SO THAT 
ONLY THE SOUTHERN COAST OF MA/RI/CT INCLUDING THE CAPE RECEIVE 
PRECIPITATION. ALL HAVE THEIR OWN ENSEMBLE BACKING. AT THIS POINT 
WILL RELY MAINLY ON THE GFS AS IT IS THE MIDDLE MODEL. IT DOES BEAR 
WATCHING AS POSSIBLE NORTHERN AND WESTERN SIDE OF THE WAVE COULD END 
UP WITH WINTRY PRECIP FOR A FEW HOURS. 

MEANWHILE...LATER IN THE WEEK...UPPER LEVEL LOW IN CANADA CONTINUES 
TO MOVE SLOWLY TO THE EAST BRINGING ITS ENERGY WITH IT. FLOW ENTERS 
THE REGION FROM THE NORTHWEST ON THURSDAY CARRYING WITH IT A HIGH 
PRESSURE SYSTEM FROM CANADA AND ITS ANTECEDENT COLD AIR.

DETAILS...

TUESDAY THROUGH WEDNESDAY...MODELS SEEM TO BE HAVING PROBLEMS 
RESOLVING A WAVE TRACKING UP THE STATIONARY FRONT DURING THIS TIME 
PERIOD WITH SPREAD EXPLAINED ABOVE. THE PLACEMENT OF THE JET IS 
IMPORTANT HERE BECAUSE A MORE NORTHERN PLACEMENT OF THE JET WOULD 
HAVE BETTER JET ENHANCEMENT FROM THE RIGHT REAR ENTRANCE REGION 
ALLUDING TO A MORE DEVELOPED LOW AND PRECIP THAT MOVES FURTHER 
INLAND FOR TUESDAY NIGHT. HAVE GONE WITH THE GFS FORECAST AT THIS 
POINT TO HIGHLIGHT POSSIBILITY OF PRECIP MOVEMENT NORTH INTO SOUTH 
COAST OF SOUTHERN NEW ENGLAND. WINTRY PRECIPITATION MAY RESULT FROM 
THIS WAVE ESPECIALLY ON THE NORTHERN AND WESTERN SIDE OF IT.

THURSDAY THROUGH SATURDAY...COLD FRONT MOVES OFFSHORE WITH COLD AIR 
MOVING BEHIND IT. HIGH PRESSURE COMES INTO THE REGION FROM THE SOUTH 
HOLDING COLD AIR AT BAY FOR A LITTLE WHILE. STILL HAVE PHASED UPPER 
LEVEL WINDS CARRYING MOST ENERGY OFFSHORE BEFORE IT CAN DEVELOP. FEW 
ALBERTA CLIPPERS COME IN FROM CANADA DURING THIS PERIOD AFTER THE 
FIRST HIGH PRESSURE SYSTEM MOVES OUT TO SEA. THE CLIPPERS WILL LACK 
PRECIPITATION.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT. 
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

NEAR-TERM /THROUGH MONDAY/...OVERALL HIGH CONFIDENCE. BUT LOWER
CONFIDENCE ON PTYPE TRANSITION LATE TONIGHT INTO MONDAY. 

VFR THROUGH TODAY WITH GRADUALLY LOWERING CIGS. DETERIORATING
CONDITIONS LATE TONIGHT THROUGH MONDAY WITH CIGS LOWERING TO
MVFR/IFR AS WINTRY MIX DEVELOPS. PTYPE STARTS AS SNOW EVERYWHERE
THEN TRANSITIONS TO SLEET/FZRA THEN RAIN NEAR THE COAST BY
DAYBREAK MON MORNING...WITH TRANSITION OCCURRING LATE MORNING
INTO THE AFTERNOON FURTHER IN THE INTERIOR.

KBOS TAF...HIGH CONFIDENCE IN TRENDS. TIMING OF ONSET OF SNOW
LATE TONIGHT COULD BE OFF A FEW HOURS.

KBDL TAF...HIGH CONFIDENCE IN TRENDS. TIMING OF ONSET OF SNOW
LATE TONIGHT AND TRANSITION TO SLEET COULD BE OFF A FEW HOURS.

OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...

MONDAY NIGHT AND TUESDAY MORNING...MODERATE TO HIGH CONFIDENCE IN 
MAINLY VFR CONDITIONS.

TUESDAY AFTERNOON AND NIGHT...LOW CONFIDENCE.  A PERIOD OF MVFR-IFR 
CONDITIONS CAN/T BE RULED OUT ACROSS OUR SOUTHERN ZONES IN A PERIOD 
OF SOME MIXED PRECIP/SNOW IF LOW PRESSURE GETS CLOSE ENOUGH.

WEDNESDAY AND THURSDAY...MODERATE TO HIGH CONFIDENCE IN VFR 
CONDITIONS DOMINATING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT. 
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

TONIGHT AND SUNDAY...HIGH CONFIDENCE. 

LEFT OVER SCA SEAS WILL LINGER ACROSS THE OUTER ATLANTIC WATERS
INTO SUN MORNING BEFORE DIMINISHING. NORTHWEST WIND GUSTS TO NEAR
20 KNOTS WILL CONTINUE TO DIMINISH OVERNIGHT AS PRESSURE BUILDS
IN FROM THE WEST.

SUNDAY NIGHT AND MONDAY...HIGH CONFIDENCE.  

WAVE OF LOW PRESSURE WORKING UP FROM THE SOUTH WILL RESULT IN
EASTERLY SCA WINDS GUSTS VERY LATE SUN NIGHT INTO MONDAY. GIVEN
ITS A LATE 3RD AND 4TH PERIOD EVENT WILL LET THE NEXT SHIFT HANDLE
THE MARINE HEADLINES.

OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...

MONDAY NIGHT AND TUESDAY...MODERATE TO HIGH CONFIDENCE.  

A COLD FRONT MOVES THROUGH THE REGION MONDAY NIGHT. THIS WILL
BRING WESTERLY SCA WIND GUSTS MON NIGHT INTO TUE IN THE COLD AIR
ADVECTION PATTERN.

TUESDAY NIGHT AND THURSDAY...MODERATE TO HIGH CONFIDENCE.  

CONTINUED COLD ADVECTION WILL RESULT IN AN EXTENDED PERIOD OF SCA
WIND GUSTS. MAY EVEN SEE A BRIEF PERIOD OF LOW END GALES LATE TUE
NIGHT INTO WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ250-254-255.

&&

$$
SYNOPSIS...FRANK/SIPPRELL/99
NEAR TERM...KJC
SHORT TERM...SIPPRELL
LONG TERM...99
AVIATION...KJC/FRANK
MARINE...KJC/FRANK/SIPPRELL/99