Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBOX 172339 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 739 PM EDT Mon Oct 17 2016 .SYNOPSIS... A stalled front over Southern New England this evening moves north as a warm front Tuesday morning. This will bring unseasonably warm conditions with the potential for near record high temperatures Tuesday and Wednesday. Unsettled weather likely at times Thu and Fri. Not as warm late week but still mild for mid Oct. A drying and cooling trend likely next weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
No major changes to the forecast this evening. Tweaked conditions to reflect observed trends. Tonight... The increasing low level southwest flow will push the stalled front back to the north overnight bringing warm air back into our region. Moisture values increase with 1.5 inch PW values moving across during the night. The low level flow over the front will be strongest in Western MA and CT. This would be the best chance for any low level lift/forcing that could generate any showers. Much better chance to the north and west of our area. We will maintain slight chance pops over our area during the night. But most areas will be dry. Dew points in the mid 50s initially may nudge up a few degrees by morning. This should limit min temps to no lower than the mid 50s to around 60. Due to the expected cloud cover, we do not anticipate any fog.
-- End Changed Discussion --
&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Unseasonably warm weather is in store for the region. Southwest flow and increasing sunshine Tuesday will mix the column to at least 900 mb. Temps at 900 mb fully mixed would support max sfc temps around 80. If the mixing reaches 850 mb it would support mid 80s. Meanwhile winds in the mixed layer will be around 25 knots. Expect gusty southwest winds near 25 knots. Dew points will remain 55 to 60 Tuesday night. This will mean another mild night with readings in the upper 50s and low 60s. If winds diminish sufficiently overnight, this would allow patches of fog to form. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Unseasonably warm Wednesday, with near record high temperatures * Widespread showers possible Friday * Drying and cooling trend likely next weekend Wednesday... Southeast to west winds continue, providing a little downslope component across eastern MA. Plenty of sunshine will mean another summer-like day. High temperatures expected to approach the records, which are in the 81-84 degree range. See the climate section below for more information. A weak cold front should cross our region Wednesday night. This front could produce some showers. Thursday... A weak front along the the south coast of New England is anticipated to move back north as a warm front during the day. While this front is nearby, cannot rule out the possibility for some showers during the day. More clouds and easterly winds should mean seasonable high temperatures. Thursday night and Friday... Showers look to be most widespread during this period. The timing of various weather features will be crucial to the actual outcome. Latest run of the GFS has much more amplified mid level trough than the ECMWF. Thus, the GFS brings a potentially subtropical or tropical low much closer to our region than the ECMWF. In addition, a low pressure is forecast to move through the Great Lakes into Quebec. Just about all of the models try to establish some form of energy transfer, and develop a secondary low pressure somewhere of the Mid Atlantic coast. Were this to occur, our region would be more likely to get a soaking rain, if this secondary low pressure gets close enough. This is where the timing of all the major weather features will come into play. If the mid level trough is more like the ECMWF solution, then most of the moisture plume stays off to our east. A solution more like the GFS gets us some much-needed rain. At this time, only have moderate confidence in this portion of the forecast. We`re still a day or two away from getting better sampling of the shortwave energy which will ultimately amplify the mid level longwave trough over the eastern USA. Will just have to wait a bit more until this happens to have a better idea on the likely outcome. Saturday into Monday... Risk for showers may linger into a portion of Saturday. However, upper air pattern is progressive, so trend will be for drier and cooler weather later this weekend. Cooler weather persists into Monday, with below normal temperatures. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/... Tonight...High confidence. VFR. Patchy MVFR cigs along the NH border late. Patchy MVFR/IFR vsbys and cigs possible toward the south coast. Low confidence in IFR. Tuesday...Moderate to high confidence. VFR. Increasing SW winds with gusts 25 knots in the afternoon. Tuesday night...Moderate to high confidence. VFR. Diminishing wind. Areas of IFR cigs/vsbys in developing fog overnight. Outlook /Wednesday through Saturday/... Wednesday...Any lingering MVFR conditions in patchy fog lifts to a SCT-BKN VFR deck. Dry weather prevails. Thursday and Friday...VFR likely to start but then lowering to MVFR or IFR with a risk of rain. High confidence in trends, but low confidence in details. Saturday...Becoming drier. Mainly MVFR to IFR during the day, with slow improvement to VFR Saturday night. Low confidence in timing.
-- End Changed Discussion --
&& .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Tonight... A cold front will likely stall across the waters and southern New England this evening. This front will slowly return north as a warm front late tonight. Winds will remain light much of the night. A 3-4 foot east swell will continue on the eastern waters. A Small Craft Advisory continues on these eastern waters for the combined seas. Tuesday... As the front moves to the north Tuesday, winds will pick up out of the southwest, with gusts 25 to 30 knots by Tuesday afternoon. These will slowly diminish in the evening. A 3-foot east swell will linger on the eastern waters through the day. A Small Craft Advisory will be in effect on most waters for both winds and seas. Tuesday night... Diminishing winds, but seas linger at 5-6 feet. Small Craft advisory may be needed for some of the waters. Outlook /Wednesday through Saturday/... Wed...winds diminish as a weakening cold front sags into the region during the night. Thus, seas will subside as well. Dry weather and good vsby, although risk of patchy fog toward Thu morning. Thu...onshore winds as a low pres enters PA and NY state. Low risk for showers and areas of fog. Friday into Saturday...This is a complicated period, which will be dominated by the exact track and strength of a potentially subtropical or tropical low off the East Coast of the USA. Expecting increasing E to SE winds Friday, which will start to build seas. Eventually, these winds turn N to NW Friday night into Saturday. Low confidence in the timing, but moderate confidence in the trend. While expecting rough seas to develop, mainly due to large southeast swell, we may be underforecasting them at this point. Should the aforementioned low off the East Coast get closer to our region than currently forecast, wind waves would also be increased, resulting in higher significant wave heights. Mariners should pay close attention to the forecast during the course of this week, and adjust their plans, as needed. && .CLIMATE... Record High Temperatures: Tuesday October 18th Wednesday October 19th Boston 82 in 1947 Boston 84 in 1945 Worcester 85 in 1908 Worcester 81 in 1963 Providence 85 in 1908 Providence 81 in 1945 Hartford 80 in 1968 Hartford 82 in 1963 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from noon to 8 PM EDT Tuesday for ANZ232>237-256. Small Craft Advisory until 8 PM EDT Tuesday for ANZ250-254-255. && $$ SYNOPSIS...WTB/Belk NEAR TERM...WTB/Belk SHORT TERM...WTB LONG TERM...Belk AVIATION...WTB/Belk MARINE...WTB/Belk CLIMATE... is the U.S. government's official web portal to all federal, state and local government web resources and services.