Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
405 AM EDT MON MAR 30 2015

.SYNOPSIS...
A COLD FRONT SWEEPS ACROSS NEW ENGLAND TODAY BRINGING A FEW
RAIN AND SNOW SHOWERS. A FAST-MOVING AREA OF LOW PRESSURE PASSES
SOUTH OF NEW ENGLAND TUESDAY NIGHT...POTENTIALLY BRINGING MORE
LIGHT RAIN AND/OR SNOW SHOWERS. A MORE SIGNIFICANT STORM MAY
APPROACH LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT CROSSING ONTARIO AND OHIO DURING THE NIGHT WILL MOVE
EAST TODAY...CROSSING NEW ENGLAND DURING THE AFTERNOON. NORTHERN
STREAM UPPER JET WILL BE IN POSITION DURING THIS TIME WITH THE
LEFT EXIT REGION OVER SOUTHERN NEW ENGLAND. THIS WILL PROVIDE UPPER
VENTING OVERLAID ABOVE LOW LEVEL CONVERGENCE OF THE FRONT. THIS
SHOULD SUPPORT SHOWERS. A FEW LIGHT ONES IN CENTRAL NEW YORK
OVERNIGHT MAY REACH OUR AREA THIS MORNING. THE BEST CHANCE FOR
SHOWERS SHOULD COME ALONG AND AHEAD OF THE TRANSITING COLD FRONT.
TIMING WOULD BE MIDDAY/EARLY AFTERNOON WEST AND MID AFTERNOON
EAST.

TEMPERATURE PROFILES INITIALLY FAVOR SNOW. BUT EXPECTED WARMING IN
THE SOUTHERLY FLOW THIS MORNING SHOULD CHANGE THIS TO RAIN. ANY
SNOW ACCUMULATION SHOULD BE LIMITED TO AN INCH OR LESS...MOSTLY
LESS.

PRESSURE FALLS OF 1MB/HR OR MORE LEAD THIS FRONT. EXPECT
INCREASING SOUTHWEST WINDS DURING THE MORNING AND MIDDAY.
PRESSURES RISE BEHIND THE FRONT BUT NOT AS STRONGLY. BUT COLD
ADVECTION MAY INDUCE MIXING OF 25 KNOT GUSTS TO THE SURFACE AFTER
THE FRONT MOVES THROUGH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
COLD ADVECTION CONTINUES TO SUPPORT MIXING INTO THE NIGHT. WINDS
ABOVE THE SURFACE WILL BE 30-40 KNOTS...EXPECT SOME OF THIS TO MIX
TO THE SURFACE IN GUSTS. BASED ON TEMPERATURES UPSTREAM...EXPECT
LOWS IN THE MID 20S TO LOWER 30S.

TUESDAY...
WEAK HIGH PRESSURE WILL KEEP THE WEATHER DRY MUCH OF THE DAY.
ANOTHER NORTHERN STREAM SHORTWAVE RACES SOUTHEAST ACROSS THE GREAT
LAKES DURING THE DAY. THIS WILL SUPPORT A CLIPPER LOW THAT MOVES
ACROSS THE MID ATLANTIC STATES DURING THE AFTERNOON. FORECASTS
FROM THE 00Z MODEL SUITE ARE FARTHER NORTH THAN PREVIOUSLY WITH
THE ECMWF FARTHEST SOUTH. ALL MODELS BRING SOME MEASURABLE PCPN
INTO CT BY EVENING...THE GFS COVERS AREAS SOUTH OF THE MASS
PIKE...AND THE NAM HAS MEASURABLE PCPN EVERYWHERE.

TEMPERATURE PROFILES SUGGEST RAIN MOST PLACES EXCEPT SNOW IN THE
HILLS. TIMING OF THE PCPN WOULD BE AFTER 21Z. WE HAVE SHIFTED
OUR POPS FARTHER NORTH WITH CHANCE POPS REACHING TO ALONG/SOUTH OF
THE MASS PIKE BY 00Z.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

HIGHLIGHTS...

* ALBERTA CLIPPER MOVES THROUGH TUESDAY NIGHT 
* MODERATING SPRING-LIKE TEMPS LATE THIS WEEK
* INCREASING CHANCES FOR PRECIP DURING THE EASTER WEEKEND

OVERVIEW...

NORTHWEST FLOW WILL CONTINUE OVER THE NORTHEAST WITH AN ALBERTA 
CLIPPER MOVING THROUGH TUESDAY NIGHT. RIDGING OVER THE GREAT LAKES 
WILL BUILD INTO NEW ENGLAND BY WED INTO THURSDAY. WESTERN TROUGH 
WILL MOVE ACROSS THE CONUS AS A COLD FRONT REACHING THE NORTHEAST 
LATE THUR THROUGH SAT. THIS SYSTEM IS ALSO AIDED BY AN UPPER LOW 
CIRCLING AROUND HUDSON BAY WHICH WILL LOWER HEIGHTS IN THE NORTHEAST 
BY NEXT WEEKEND.

OVERALL TREND IN THE GUIDANCE HAS LEAD TO A LOWER CONFIDENCE. MODEL 
GUIDANCE HAS TRENDED NORTHWARD WITH THE RUN FOR THE ALBERTA CLIPPER 
INCREASING PRECIP FOR SOUTHERN NEW ENGLAND. 00Z GUIDANCE CONTINUES
TO SHOW HIGH PRESSURE ON WED BUT THE OVERALL COLD FRONT IS SPLIT
AMONGST GUIDANCE. THE GFS REMAINS QUICKER WITH THE SFC FRONT
THROUGH THE NORTHEAST/MID-ATLANTIC FRI COMPARED TO THE OTHER
GUIDANCE. THEREFORE CONTINUED TO BLEND WITH WPC UNTIL THE MODELS
ARE MORE IN AGREEMENT.

DETAILS...

* TUESDAY NIGHT...MODERATE CONFIDENCE. 

NEXT SHORTWAVE WILL QUICKLY DIVE THROUGH THE FLOW FROM CANADA AND 
MOVE JUST SOUTH OF SOUTHERN NEW ENGLAND. OVERALL GUIDANCE HAS 
TRENDED TOWARDS WHICH IS INCREASING CONFIDENCE THAT RAIN/SNOW WILL 
OCCUR. BELIEVE THAT LOCATIONS ALONG AND SOUTH OF THE PIKE HAVE THE 
BEST CHANCE TO SEE ANY SNOW ACCUMS ONCE TEMPS DROP DUE TO 
WETBULBING. STILL NEED TO WATCH THIS SYSTEM CLOSELY AS THERE IS 
STILL SPREAD AMONGST THE MODELS. RIGHT NOW ANTICIPATE A QUICK 1-2 
INCHES OF SNOW ALONG THE SOUTH COAST...CAPE AND ISLAND. 

* WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE. 

WEAK RIDGE WILL BUILD BEHIND THE CLIPPER SYSTEM WED INTO WED NIGHT. 
THIS WILL ALLOW FOR STRONG HIGH PRESSURE TO BUILD OVER SNE. LATEST 
TRENDS IN THE GUIDANCE SUGGEST THAT THURSDAY WILL STAY DRY AS HIGH 
PRESSURE IS SLOW TO MOVE OFFSHORE. TEMPERATURES WILL BE ON THE 
INCREASE WITH MID 40S ON WEDNESDAY AND MID 50S ON THURSDAY AS WAA 
INCREASE AHEAD OF APPROACHING SYSTEM. 

* THURSDAY NIGHT INTO SATURDAY...LOW CONFIDENCE IN TIMING. MODERATE 
  CONFIDENCE IN PRECIP OCCURRING. 

QUASI-ZONAL FLOW WILL SUPPORT CHANGEABLE TEMPERATURES... MODULATED 
BY THE SFC COLD FRONT THU INTO SAT. OVERNIGHT MIN TEMPS WILL BE ON 
THE MILD SIDE IN ADVANCE OF THE COLD FRONT FINALLY GETTING ABOVE 
FREEZING FOR NEW ENGLAND. IN FACT TEMPERATURES COULD BE THE WARMEST 
THEY HAVE BEEN IN OVER FOUR MONTHS FOR THE REGION. HOWEVER AS THE 
FRONT PASSES EXPECT TEMPS TO RETURN TO BELOW AVG BY ABOUT 5-15F.

ANTICIPATE THIS COLD FRONT TO CROSS THE AREA EITHER THURSDAY 
NIGHT/GFS OR FRIDAY/EC AND CMC. APPEARS THAT A WAVE WILL DEVELOP 
ALONG THE FRONT SOMETIME LATE FRIDAY OR SAT. BECAUSE OF THE TIMING 
DIFFERENCE...DECIDED TO BLANKET THIS TIME FRAME WITH CHC POPS AND 
HOPEFULLY WITHIN THE NEXT 24 HRS CAN PUT BETTER DETAIL INTO THE 
FORECAST. CAN STAY THAT THIS SYSTEM DOES LOOK WARM SO EXPECT PRECIP 
TYPE TO BE MORE OF THE RAIN FORM. HOWEVER ON THE BACK SIDE OF THE 
FRONT COULD SEE SOME WET FLAKES. 

SUNDAY...MODERATE CONFIDENCE.

HIGH PRESSURE BEGIN TO BUILD INTO THE REGION BEHIND THE COLD
FRONT. TEMPS WILL CONTINUE TO BE BELOW AVERAGE FOR THIS
TIMEFRAME.


&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM...HIGH CONFIDENCE THROUGH MONDAY NIGHT

TODAY...VFR. BRIEF MVFR POSSIBLE IN SCATTERED RAIN AND SNOW
SHOWERS. A COLD FRONT MOVES THROUGH FROM WEST TO EAST DURING
MIDDAY TO MID-AFTERNOON. GUSTY WEST WINDS BEHIND THE FRONT MAY
REACH 25-30 KNOTS.

TONIGHT...VFR. GUSTY WEST WINDS BEHIND THE FRONT MAY REACH 25-30
KNOTS.

TUESDAY...VFR. MVFR CIGS/VSBYS POSSIBLE ACROSS CT AND RI TOWARD
EVENING.

KBOS TAF...HIGH CONFIDENCE.

KBDL TAF...HIGH CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...HIGH CONFIDENCE.

TUESDAY NIGHT...VFR FOR MOST OF THE PERIOD. MAY SEE MVFR SOUTH OF 
MASS PIKE IN RAIN/SNOW SHOWERS.

WEDNESDAY INTO THURSDAY...VFR.

FRIDAY...MVFR IN SHOWERS...COULD SEE IFR CONDITIONS BY FRI EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM...TODAY THROUGH TUESDAY

HIGH CONFIDENCE.

TODAY...A COLD FRONT CROSSES NEW ENGLAND DURING THE AFTERNOON AND
MOVES ACROSS THE WATERS TOWARD EVENING. SOUTHWEST WINDS WILL GUST
TO NEAR 25 KNOTS IN ADVANCE OF THE FRONT. WEST WINDS TRAILING THE
FRONT WILL GUST 25-30 KNOTS. SEAS WILL BUILD TO 5-7 FEET ON THE
OUTER WATERS AND RHODE ISLANDS/BLOCK ISLAND SOUNDS. SMALL CRAFT
ADVISORY CONTINUES ON ALL WATERS. 

TONIGHT...GUSTY WEST WINDS CONTINUE OVERNIGHT. SEAS OF 5-7 FEET
LINGER ON THE OUTER WATERS AND RHODE ISLAND SOUNDS. SMALL CRAFT
ADVISORY CONTINUES.

TUESDAY...GUSTY WINDS WILL DIMINISH AS WEAK HIGH PRESSURE BUILDS
BRIEFLY OVER THE WATERS. LINGERING SMALL CRAFTS ON THE OUTER
WATERS.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE.

TUESDAY NIGHT...QUICK-MOVING SYSTEM WILL MOVE OVER SOUTHERN
WATERS. THIS WILL KEEP BOTH SEAS AND WINDS ABOVE SMALL CRAFT
ADVISORY THRESHOLDS. THERE IS A LOW PROB OF GALES FORCE WINDS. 

WEDNESDAY INTO THURSDAY...HIGH PRESSURE WILL ARRIVE...ALLOWING
FOR SEAS AND WINDS TO RELAX.

FRIDAY...ANOTHER COLD FRONT APPROACHES THE WATERS...RESULTING IN
INCREASING SOUTHWEST WINDS AND SEAS.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT TUESDAY FOR ANZ231-232.
     SMALL CRAFT ADVISORY UNTIL 3 AM EDT TUESDAY FOR ANZ233-234.
     SMALL CRAFT ADVISORY UNTIL 3 AM EDT TUESDAY FOR ANZ230-236.
     SMALL CRAFT ADVISORY UNTIL 4 PM EDT TUESDAY FOR ANZ235-237-256.
     SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR ANZ250-254-255.
     SMALL CRAFT ADVISORY UNTIL 9 AM EDT TUESDAY FOR ANZ251.

&&

$$
SYNOPSIS...WTB/DUNTEN
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...DUNTEN
AVIATION...WTB/DUNTEN
MARINE...WTB/DUNTEN

National Weather Service Glossary of Abbreviations