Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
325 PM EST SUN DEC 28 2014

.SYNOPSIS...
A COLD FRONT CROSSING NEW ENGLAND WILL MOVE OFFSHORE BY EVENING. 
HIGH PRESSURE BUILDS SOUTH FROM CANADA AND THEN SPREADS ACROSS THE
USA FOR MUCH OF THE WEEK. THIS WILL MEAN A DRY AND COLD SPELL FOR
NEW ENGLAND. A STORM MOVING OUT OF THE SOUTHERN PLAINS WILL MOVE
TO THE GREAT LAKES SATURDAY AND BRING RAIN TO SOUTHERN NEW ENGLAND
OVER NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THROUGH 7 PM...
COLD FRONT CROSSING NEW ENGLAND DURING THE AFTERNOON. THERE ARE
LOTS OF CLOUDS WITH THIS FRONT BUT MOST OF THE ASSOCIATED SHOWERS
HAVE MOVED OFFSHORE. PAST MOVEMENT OF THE FRONT EXTRAPOLATES IT
OFF THE COAST BY 00Z. SATELLITE IMAGERY SHOWS LOTS OF CLOUDS
EXTENDING BEHIND THE FRONT...SO SKIES SHOULD REMAIN MOSTLY CLOUDY
THROUGH THE REMAINDER OF THE AFTERNOON/EVENING.

TONIGHT...
MUCH OF THE AIRMASS DRIES EARLY TONIGHT WHICH WOULD SUPPORT
CLEARING SKIES. CROSS SECTIONS SHOW LINGERING MOISTURE /OVER 70
PCT RH/ NORTH OF THE MASS PIKE BELOW 900 MB THROUGH 12Z MONDAY.
AREAS SOUTH OF THE PIKE ARE LESS MOIST BUT NOT BONE DRY. SO WILL
KEEP CLOUDS AROUND EARLY NIGHT WITH A CLEARING TREND OVERNIGHT.
TEMPERATURES IN THE 20S INLAND AND 30S ALONG THE COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
FLAT FLOW ALOFT WITH SURFACE HIGH PRESSURE BUILDING THROUGH THE
GREAT LAKES INTO CANADA. THIS SHOULD BE A DRY PERIOD WITH MOSTLY
CLEAR SKIES. MIXING DURING THE DAY IS FORECAST TO REACH 900 MB.
WINDS IN THIS LAYER WILL BE 15-20 KNOTS...SO WE WOULD EXPECT GUSTS
UP TO 20 KNOTS DURING THE DAY. TEMPS AT 900 MB OF -3C TO -5C
WOULD SUPPORT MAX SFC TEMPS OF 40-45. BUT WITH ZONAL FLOW ALOFT
AND COLD ADVECTION IN PLAY WE WILL EDGE CLOSE TO SEASONAL NORMALS
WITH FORECAST TEMPS IN THE MID 30S TO LOWER 40S.

MONDAY NIGHT SHOULD ALSO BE DRY WITH SEASONAL MINS IN THE UPPER
TEENS AND 20S.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* DRY WEATHER THROUGH MOST OF THE WORK WEEK
* SEASONABLE TO PERHAPS SLIGHTLY BELOW NORMAL TEMPERATURES EXPECTED
* NEXT SHOT OF PRECIP POTENTIALLY SATURDAY

MODELS ARE IN GOOD AGREEMENT THROUGH MUCH OF THE LONG TERM WITH 
LIGHT WINDS AND COOLER TEMPERATURES TO START THE WEEK OFF.  SURFACE 
FLOW SHIFTS TO THE SOUTHWEST AS LOW PRESSURE MOVES OVER HUDSON BAY 
WITH MODERATING TEMPERATURES EXPECTED THURSDAY AND FRIDAY.  MODELS 
START TO SHOW SOME TIMING DISCREPANCIES FOR FRIDAY INTO THE WEEKEND 
WITH THE ECMWF A BIT FASTER THAN THE GFS WITH A LOW PRESSURE SYSTEM 
MOVING THROUGH QUEBEC AND INTO THE MARITIMES.  AT THIS POINT...WILL 
USE A BLEND OF THE MODELS FOR THIS TIME PERIOD WHILE THE NEXT FEW 
RUNS SHAKE OUT.

TUESDAY AND WEDNESDAY...DRY BUT MORE SEASONABLE WEATHER IS EXPECTED 
AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES AND SURFACE WINDS ALLOW 
COLDER AIR TO DRAIN FROM THE NORTH.

THURSDAY AND FRIDAY...WINDS SHIFT TO THE SOUTHWEST AS LOW PRESSURE 
MOVES OVER HUDSON BAY AND THEN EASTWARD THROUGH QUEBEC. WHILE THERE 
IS A COLD FRONT ASSOCIATED WITH THE LOW...MODELS ARE FORECASTING 
THIS TO STAY WELL TO OUR NORTH AT THIS TIME.  THEREFORE...DRY 
WEATHER WILL PERSIST BUT TEMPERATURES WILL MODERATE A BIT.

LATE FRIDAY THROUGH SUNDAY...THERE IS A SIGNIFICANT AMOUNT OF 
UNCERTAINTY FOR THIS TIME PERIOD DUE TO COMPLEXITIES WITH THE FLOW 
FAR UPSTREAM OF SOUTHERN NEW ENGLAND. THIS WILL AFFECT HOW THE 
NORTHERN AND SOUTHERN STREAM END UP INTERACTING AND ULTIMATELY HOW 
LOW PRESSURE ENDS UP EVOLVING OVER THE EASTERN U.S. AND CANADA. AT 
THIS POINT THE MODELS ARE GOING WITH LOW PRESSURE MOVING ACROSS THE 
GREAT LAKES INTO CANADA...BRINGING A WARM FRONT AND THEN A COLD 
FRONT OVER SOUTHERN NEW ENGLAND.  THIS WOULD RESULT IN WIDESPREAD 
PRECIPITATION OVER THE REGION...BUT RIGHT NOW IT LOOKS LIKE A WARM 
STORM...SO WOULD BE MOSTLY RAIN.  WILL USE A BLEND OF MODELS FOR 
THIS TIME PERIOD WHILE WE WAIT AND SEE HOW THE SITUATION EVOLVES 
UPSTREAM.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

THROUGH 00Z...HIGH CONFIDENCE. GENERALLY VFR WITH CLOUD BASES
3500-4000 FEET AND 10 THOUSAND FEET. AN MVFR LAYER AROUND 2500
FEET MOVED THROUGH THE BERKSHIRES INTO THE CT VALLEY AND SHOULD
DISSIPATE BY EVENING.

TONIGHT...MODERATE-HIGH CONFIDENCE. STILL LOTS OF CLOUDS UPSTREAM
AND FORECAST MODELS SUGGEST CLOUDS WILL LINGER THROUGH MIDNIGHT
BEFORE CLEARING. VFR.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE. VFR. NORTHWEST WINDS
GUSTING 15-20 KNOTS MONDAY MIDDAY AND AFTERNOON.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY AND WEDNESDAY...HIGH CONFIDENCE. VFR.

THURSDAY AND FRIDAY...MODERATE CONFIDENCE.  MAINLY VFR.  COULD SEE 
SOME MVFR CIGS VERY LATE FRIDAY NIGHT AS WARM FRONT APPROACHES.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH MONDAY/...MODERATE TO HIGH CONFIDENCE.

TONIGHT...NORTHWEST WINDS GUSTING 20 TO 25 KNOTS NEARSHORE. FIVE
FOOT SEAS ON THE OUTER WATERS. WINDS DIMINISH AND SEAS WILL
SUBSIDE EARLY TONIGHT. WE WILL LET THE SMALL CRAFT ADVISORY
NEARSHORE EXPIRE AT 7 PM. HOWEVER A SMALL CRAFT ADVISORY WILL
REMAIN POSTED FOR THE SOUTHERN AND SOUTHEAST OUTER WATERS UNTIL
MONDAY MORNING BECAUSE OF LINGERING 5 FT SEAS.

MONDAY...NORTHWEST WINDS GUSTING 20 TO 22 KNOTS. SEAS GENERALLY 3
TO 4 FT OVER THE OUTER WATERS. NO HEADLINES EXPECTED.

MONDAY NIGHT...WINDS AND SEAS REMAIN BELOW SMALL CRAFT THRESHOLDS.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY THROUGH WEDNESDAY...HIGH CONFIDENCE. QUIET BOATING 
CONDITIONS EXPECTED.  NORTHERLY WINDS TUESDAY WILL SHIFT TO THE 
WEST WEDNESDAY.

WEDNESDAY NIGHT AND THURSDAY...WESTERLY WINDS AND SEAS START TO 
BUILD AS HIGH PRESSURE MOVES AWAY FROM THE WATERS.  SMALL CRAFT 
CONDITIONS ARE LIKELY WEDNESDAY NIGHT AND THERE IS A LOW PROBABILITY 
OF GALE FORCE WIND GUSTS THURSDAY.

FRIDAY...WINDS AND SEAS SUBSIDE AS HIGH PRESSURE CRESTS OVER 
SOUTHERN NEW ENGLAND AND THE WATERS.  QUIET BOATING CONDITIONS ARE 
EXPECTED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR 
     ANZ231>235-250-251.
     SMALL CRAFT ADVISORY UNTIL 8 AM EST MONDAY FOR ANZ254>256.

&&

$$
SYNOPSIS...WTB/THOMPSON
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...RLG
AVIATION...WTB/RLG
MARINE...WTB/RLG

National Weather Service Glossary of Abbreviations