005 FXUS61 KBOX 200556 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1256 AM EST SUN JAN 20 2013 .SYNOPSIS... A SOUTHWEST FLOW OF MILDER AIR WILL WORK INTO THE REGION THROUGH THE FIRST PART OF SUNDAY AHEAD OF A STRONG COLD FRONT. A COASTAL STORM WILL BRING ACCUMULATING SNOWFALL ACROSS MOST OF THE REGION MONDAY NIGHT INTO TUESDAY. OTHERWISE EXPECT BITTER COLD TEMPS FOR NEXT WEEK FOLLOWED BY ANOTHER STORM SYSTEM BY THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1255 AM UPDATE... A SOUTHWEST LOW LEVEL JET WILL CONTINUE TO INCREASE VERY EARLY THIS MORNING. THIS WILL PROBABLY CAUSE THE BOUNDARY LAYER TO MIX OUT IN SOME LOCATIONS IN AREAS THAT HAD DECOUPLED ACROSS THE INTERIOR. THEREFORE...AREAS ACROSS THE INTERIOR THAT HAVE FALLEN BELOW FREEZING MAY START TO RISE OVER THE NEXT COUPLE OF HOURS. ACROSS THE COASTAL PLAIN...TEMPS MAY HOLD IN THE UPPER 30S TO THE MIDDLE 40S OVERNIGHT WITH SOUTHWEST WINDS CONTINUING TO BLOW. WARM ADVECTION SHOULD CONTINUE TO RESULT IN CONSIDERABLE CLOUDINESS VERY EARLY THIS MORNING. THE BULK OF THE FORCING/DYNAMICS WILL REMAIN TO OUR NORTHWEST OUR REGION. LATEST RADAR IMAGERY SHOWING SOME WEAK RETURNS ACROSS NORTHWEST MA/SOUTHWEST NH...SO CAN/T RULE OUT A PASSING SNOW FLURRY OR TWO BUT NOTHING MORE THAN THAT EXPECTED. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... SUNDAY... AS LOW PRESSURE WORKS ITS WAY THROUGH QUEBEC AND INTO THE MARITIMES...A COLD FRONT WILL MOVE THROUGH SOUTHERN NEW ENGLAND SUNDAY. DESPITE THIS...IT WILL TAKE A BIT LONGER FOR COLDER AIR TO MOVE INTO THE REGION SO HIGH TEMPERATURES ARE LIKELY TO BE AS WARM OR WARMER THAN TODAY. WITH NOT A LOT OF MOISTURE AVAILABLE TO RESULT IN SHOWERS...EXPECT THE FRONT TO COME THROUGH HERE DRY. EXPECT ANOTHER WINDY DAY WITH WESTERLY WINDS GUSTING UP TO 45 MPH ON THE COASTAL PLAIN AND UP TO 40 MPH ACROSS THE INTERIOR. WE MAY NEAR WIND ADVISORY CRITERIA AT A FEW LOCATIONS. WILL HAVE TO KEEP AN EYE ON THIS. MIXING WILL BE BETTER BEHIND THE COLD FRONT...BUT THE LOW LEVEL JET WILL BE A LITTLE WEAKER. TO AVOID DOUBLE HAZARDS WITH THE WIND ADVISORY CURRENTLY...WILL CONTINUE TO HIGHLIGHT THIS POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK AND ALLOW LATER SHIFTS TO RAISE THE WIND ADVISORY WHEN THE CURRENT ONE HAS EXPIRED. SUNDAY NIGHT... HIGH PRESSURE BUILDS INTO THE AREA. ALSO...STRONG COLD AIR ADVECTION WILL GET GOING OVERNIGHT...DROPPING TEMPS INTO THE TEENS MOST LOCATIONS. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... BIG PICTURE... UPPER FLOW ON MONDAY HAS HUDSON BAY LOW WITH CYCLONIC FLOW EAST OF THE ROCKIES WHILE HIGH PRESSURE RIDGE SITS ALONG THE PACIFIC COAST. THE LOW DIPS SOUTH ACROSS EASTERN CANADA AND THE NORTHEAST USA WITH SEVERAL SHORTWAVES MOVE THROUGH THIS FLOW. THE FIRST SHORTWAVE MOVES THROUGH NEW ENGLAND EARLY WEEK...THE SECOND COMES THROUGH MIDWEEK. A THIRD SHORTWAVE MOVES IN FROM THE NORTH PACIFIC WEDNESDAY AND CROSSES NORTH AMERICA BY THE END OF THE WEEK. NEGATIVE HEIGHT ANOMALY OF 1-2 STANDARD DEVIATIONS OVER THE NORTHEAST USA FROM TUESDAY THROUGH AT LEAST THURSDAY. WOULD EXPECT THE THIRD SHORTWAVE TO MAINTAIN THE ANOMALY LATE WEEK. SO TEMPERATURES FOR THE LONG TERM PERIOD SHOULD REMAIN COLDER THAN NORMAL. THE DAILIES... MONDAY-TUESDAY... SHORTWAVE MOVING ACROSS THE GREAT LAKES SPINS UP A COASTAL LOW MONDAY AFTERNOON AND NIGHT. CROSS SECTIONS OF RH AND LIFT SHOW DEEP LAYER OF MOISTURE AND LIFT MONDAY NIGHT WITH PREFERENCE FOR THE SOUTH COASTS OF RI AND MASS. THIS IS SENSIBLE AS IT TIME WELL FOR THE PASSAGE OF THE LEFT EXIT REGION OF THE UPPER JET SUPPORTING THE SHORTWAVE. WE WILL BE ON THE NORTH SIDE OF THE SYSTEM WITH COLD AIR DRAINING IN...SO PTYPE SHOULD BE SNOW. SNOWFALL POTENTIALS CONTINUE TO LOOK LIKE 1-2 INCHES GENERALLY AND 2- 5 INCHES SOUTH COAST. IF THIS REMAINS CONSTANT IN THE NEXT COUPLE OF FORECASTS...AN ADVISORY MAY BE NEEDED ESPECIALLY FOR SOUTHERN RI AND PARTS OF SOUTHEAST MASS. AS THE COASTAL LOW MOVES OFF ON TUESDAY...NORTHWEST WINDS WILL INCREASE WITH POTENTIAL GUSTS 20-30 KNOTS IN THE AFTERNOON ESPECIALLY ALONG THE COAST. TEMPS ON TUESDAY WILL CLIMB SLOWLY AND REMAIN BELOW FREEZING ALL AREAS. THE COMBINATION OF THE TWO WILL BRING WIND CHILLS IN THE SINGLE NUMBERS TUESDAY...COOLING BELOW ZERO TUESDAY NIGHT. SOME AIR TEMPS WILL ALSO COOL BELOW ZERO IN THE NORTHWEST. THE NORTHWEST WINDS AND COLD AIR WILL ALSO BRING OCEAN EFFECT SNOW SHOWERS OFF THE OUTER CAPE TUESDAY NIGHT. WEDNESDAY-THURSDAY... THE SECOND SHORTWAVE WILL BRING CLOUDS TO THE REGION BUT LIMITED MOISTURE SO MOSTLY CLOUDS. ANOTHER SHOT OF COLD AIR WILL MAINTAIN BELOW NORMAL TEMPS WITH DAYTIME HIGHS IN THE TEENS AND LOWER 20S...NIGHT TEMPS FROM THE SINGLE NUMBERS BELOW ZERO IN THE NORTHWEST TO THE LOWER TEENS ALONG THE COAST. FRIDAY-SATURDAY... THE THIRD SHORTWAVE GENERATES A SOUTHERN PLAINS LOW THAT PASSES SOUTH OF NEW ENGLAND LATE FRIDAY OR SATURDAY. A STRONG UPPER JET WILL BE IN POSITION TO SUPPORT LIFT...SO WE WILL CARRY CHANCE POPS FOR SNOW DURING THIS PERIOD. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... OVERVIEW...HIGH CONFIDENCE TODAY AND TONIGHT WITH LOW TO MODERATE CONFIDENCE ON MONDAY. TODAY AND TONIGHT...MAINLY VFR CONDITIONS OTHER THAN SOME MARGINAL MVFR CIGS/VSBYS EARLY THIS MORNING ACROSS THE FAR SOUTHEAST NEW ENGLAND COAST. ALSO...CAN/T COMPLETELY RULE OUT SOME BRIEF MARGINAL MVFR CIGS ACROSS THE INTERIOR LATER TODAY AND TONIGHT. WESTERLY WINDS WILL INCREASE LATER THIS MORNING AND AFTERNOON WITH 30 TO 40 KNOT WIND GUSTS EXPECTED. WINDS WILL REMAIN QUITE GUSTY INTO THE EVENING BEFORE GRADUALLY DIMINISHING SOME LATE. MONDAY...VFR CONDITIONS EARLY MAY GIVE WAY TO MVFR-IFR CONDITIONS DURING THE AFTERNOON IN SOME SNOW. HOWEVER...THE TIMING AND AREAL EXTENT OF ANY SNOW REMAINS UNCERTAIN. APPEARS THE BEST CHANCE FOR THIS WILL BE NEAR THE SOUTH COAST. KBOS TAF...HIGH CONFIDENCE IN TAF. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...MONDAY THROUGH THURSDAY... MONDAY-TUESDAY...VFR EARLY LOWERING TO MVFR CIGS/VSBYS IN SNOW MONDAY NIGHT AND TUESDAY MORNING...AND A PERIOD OF IFR POSSIBLE. CONDITIONS IMPROVE TUESDAY AFTERNOON...BUT MVFR/IFR LINGERS WITH OCEAN EFFECT SNOW SHOWERS DEVELOPING JUST EAST OF CAPE COD. COLDER THAN NORMAL TEMPERATURES. WEDNESDAY-THURSDAY...GENERALLY VFR. OCEAN EFFECT SNOW SHOWERS CONTINUE EAST OF OUTER CAPE COD. COLDER THAN NORMAL TEMPERATURES. && .MARINE... HIGH CONFIDENCE THROUGH SUNDAY NIGHT. ALTHOUGH WINDS HAVE TEMPORARILY DIMINISHED BELOW GALES...THEY WILL INCREASE BACK TO GALE FORCE SUNDAY MORNING. WILL ADD BOS HARBOR AND NARR BAY TO THE GALE WARNING...SO IT WILL BE IN EFFECT FOR ALL WATERS. WESTERLY WINDS WILL GUST BETWEEN 35 AND 45 KNOTS SUNDAY IN ASSOCIATION WITH THE APPROACHING COLD FRONT. WINDS AND SEAS WILL DIMINISH SUNDAY NIGHT AS HIGH PRESSURE BUILDS OVER THE WATERS. HOWEVER...THEY WILL REMAIN ABOVE SMALL CRAFT CRITERIA ON THE EASTERN OUTER WATERS. OUTLOOK...MONDAY THROUGH THURSDAY... MONDAY...LINGERING 5 FOOT SEAS ON THE OUTER WATERS DIMINISHING. WINDS BELOW 25 KNOTS. SNOW DEVELOPING AFTERNOON/EVENING. TUESDAY...SNOW TAPERS OFF TUESDAY AFTERNOON. INCREASING NORTHWEST WINDS WITH GUSTS 25-30 KNOTS AND LOW CONFIDENCE POTENTIAL FOR 35 KNOT WIND GUSTS ESPECIALLY ON THE OUTER WATERS. SEAS BUILDING 5-8 FEET IN THE AFTERNOON ESPECIALLY ON THE OUTER WATERS. COLDER THAN NORMAL AIR TEMPERATURES...WHICH WILL CONTRIBUTE TO DEVELOPING FREEZING SPRAY. WEDNESDAY-THURSDAY...CONTINUED NORTHWEST WINDS GUSTING 25-30 KNOTS AND 5 FOOT SEAS ESPECIALLY ON THE OUTER WATERS. CONTINUED OCEAN EFFECT SNOW SHOWERS AND FREEZING SPRAY. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ231>235-237- 250-251-254>256. GALE WARNING FROM 9 AM THIS MORNING TO 7 PM EST THIS EVENING FOR ANZ230-236. && $$ SYNOPSIS...WTB/RLG NEAR TERM...FRANK SHORT TERM...RLG LONG TERM...WTB AVIATION...FRANK/WTB MARINE...FRANK/RLG/WTB