Old Res Weather

Lexington, Massachusetts, USA

57°F

4/19/2024 4:31pm

Lexington Conditions: Clear
Temperature: 56.7°F / 13.7°C
Dew Point: 42.4°F
Relative Humidity: 59%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 30.09 in Falling Slowly
Visibility: 10 miles
Rain Today: 0.00 in
UV Index: $VPuv Low

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 162335
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
735 PM EDT Tue Apr 16 2024

.SYNOPSIS...
High pressure over southern New England will bring dry weather 
through mid week. It will be cooler Wednesday along the coast 
with sea breezes. Isolated to scattered showers across the 
interior Thursday with slightly below normal temperatures. Dry 
on Friday with high pressure in control. A cold front brings 
another round of light rain showers late Friday through 
Saturday. Turning drier Sunday and Monday.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Relatively quiet weather continues, so no major changes to the
ongoing forecast. Do think gusty winds will diminish by 8 PM for
most, and 9 PM at the latest over land. Could see some higher
gusts over the coastal water, but even there should be less than
20 kt. Brought temperatures back in line with observed trends.

Previous Discussion...

Full sunny skies out there for many in southern New England with
the exception of some widely scattered diurnal cumulus clouds
(though far fewer than yesterday). This combined with
temperatures currently in the mid to upper 60s are making for a 
fantastic Spring day across the region under dry northwest flow.
The quiet weather continues tonight beneath a building mid level 
ridge and surface high pressure. This leads to clear skies and
light winds (decoupling boundary layer) tonight allowing for
efficient radiational cooling. This means lows dipping into the 
upper 30s in our typical cold spots, closer to the mid 50s along
the coast and in urban centers.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
The mid level ridge axis shifts directly overhead on Wednesday 
leading to sunny skies for a good portion of the day and dry 
weather all day. The skies will fill in with high clouds from 
west to east starting mid morning, thickening and lowering 
through the day ahead of a warm front. Temperatures during the 
day will be quite different along the coast compared to inland 
locations thanks to a seabreeze. By afternoon we expect temps in
the low to mid 50s along the coast and low to mid 60s inland. 
The better plume of moisture arrives after sunset ahead of a 
shortwave pushing into the eastern Great Lakes. There continue 
to be considerable discrepancies amongst the guidance as to how 
far east into SNE the PWAT plume pushes, but ensembles are in 
agreement that the far better chance of wet weather will be over
western MA/CT where the much more moisture is present and 
upslope flow into the terrain will enhance lift. The GEFS and 
EPS put the chance of measurable rain over 90% in western MA/CT 
and less than 30% in far eastern MA.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Highlights

* Isolated to scattered showers on Thu, mainly across the
  interior, with slightly below normal temperatures.

* Dry for much of Fri with temps returning to seasonable levels. 

* Cold front brings scattered showers late Fri through Sat. Mild 
  temperatures return. 

* The temperature roller coaster continues, with a return to near 
  normal temperatures and dry weather for Sun into Tue.

Southern New England will be dealing with another mid level
omega block. This time through, we should initially be located
beneath the ridge portion of this block. Currently expecting 
this mid level ridging to move off to our east towards this 
weekend, leading to a transition to a broad mid level trough 
early next week.

At the surface, high pressure should remain in control of our  
weather into Friday morning. Thus, mainly dry weather expected, 
although there could be a risk for scattered showers towards its
edges, which would be mainly across the western half of southern 
New England both Thursday and Friday. A slow moving front
Saturday should continue the risk for showers, before high
pressure arrives late this weekend into early next week.

Stayed close to the NationalBlend solution for this portion of
the forecast. Can see a scenario where rainfall chances could 
be lowered in later forecasts for Thursday and Friday.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Forecast Confidence Levels:

Low - less than 30 percent. 
Moderate - 30 to 60 percent. 
High- greater than 60 percent. 

Tonight...High Confidence. 

VFR. Calm/light NNW winds.

Wednesday...High Confidence.

VFR. Light N winds becoming variable and remaining light during 
the afternoon inland, while sea breezes develop around 10 knots 
along the coast.

Wednesday night...High confidence. 

VFR for all terminals to start. IFR cigs move into western MA/CT
terminals after 06z in showers. Light S winds becoming SE. 

KBOS TAF...High confidence in TAF.

KBDL TAF...High confidence in TAF.

Outlook /Thursday through Sunday/... 

Thursday: VFR. Breezy. Scattered SHRA.

Thursday Night: Mainly VFR, with local MVFR possible. Isolated
SHRA.

Friday: Mainly VFR, with local MVFR possible. Breezy. Slight
chance SHRA.

Friday Night through Saturday: Mainly VFR, with local MVFR
possible. Breezy. Chance SHRA.

Saturday Night: VFR. Breezy. Slight chance SHRA.

Sunday: Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent. 

Today through Wednesday Night...High Confidence.

Weak pressure gradient will keep winds and seas below Small 
Craft Advisory thresholds through Wednesday night. No fog or 
vsby issues expected.

Outlook /Thursday through Sunday/... 

Thursday through Thursday Night: Winds less than 25 kt. Seas
locally approaching 5 ft. Isolated rain showers. 

Friday: Winds less than 25 kt. 

Friday Night through Saturday: Winds less than 25 kt. Seas
locally approaching 5 ft. Chance of rain showers. 

Saturday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Slight chance of rain showers. 

Sunday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...Belk/BW
NEAR TERM...Belk/BW
SHORT TERM...BW
LONG TERM...Belk
AVIATION...Belk/BW
MARINE...Belk/BW