Your Weather

To update your location please enter your ZIP code, city, state, airport code or country in the field below. Weather by E-mail: Forecast storm alerts. Weather E-Mail Alert Sign Up »

Next 12 Hours

Forecast data from the National Digital Forecast Database.

5 Day Forecast

• Wednesday
• 
• High: 75 °
• Low: 55 °
• T-Storms

• Thursday
• 
• High: 68 °
• Low: 46 °
• Clear

• Friday
• 
• High: 68 °
• Low: 46 °
• Clear

• Saturday
• 
• High: 77 °
• Low: 50 °
• Clear

• Sunday
• 
• High: 75 °
• Low: 57 °
• Partly Cloudy

Area forecast discussion 
National Weather Service Taunton Massachusetts 
1035 am EDT Wednesday may 16 2012 


Synopsis... 


Scattered showers and a few thunderstorms are expected ahead of a 
cold front today and into this evening. The cold front will then 
bring dry weather Thursday into early next week along with a warming 
trend. 


&& 


Near term /until 6 PM this evening/... 


***a few strong to severe thunderstorms are possible across the 
interior late this afternoon/evening*** 


10 am update... 


Better convergent subtropical axis with a focus of low-level flow 
moves offshore as the northern stream trough axis through the Great Lakes region 
acts as a kicker. Anticipate the broad area of heavy rain with 
embedded thunderstorms to progress offshore into the midday hours 
and weaken as the dry tongue ahead of the northern stream system advects 
northeastward through the middle-upper levels /this can be seen in the 12z aly 
sounding...but interestingly theres indications of low-level drying 
per 12z okx-chh sounding...Storm Prediction Center mesoanalysis confirms with a nose 
of drier air at 850 mb out of the W/. Continued low clouds and fog 
should be expected with the heavy rains resulting in reduced 
visibilities. Total precipitation amnts have been updated...could see another 
half inch to an inch over the cape and islands. The progressive 
nature should keep the flooding impacts to minimal. 


As for convection this afternoon...warmer air is squeezing along 
and ahead of the northern stream trough which should result in a low-level 
inversion and keep low clouds and a more stable regime over the 
central and eastern forecast areas /you can see the inversion around 850 mb 
per 12z soundings/. Further aloft /h5/ colder air is working 
ahead of the attendant cold front to the northern stream trough. Per 
satellite...the clear slot is evident...and with steepening middle- 
level lapse rates combined with boundary layer mixing through PA- 
New York...the interior northestern Continental U.S. Should destabilize with sbcapes 
around 1000 j/kg in southwesterly 0-6 km shear regime of 45 kts /looks like 
the better shear will lag the surface cold frnt/. Believe the clear 
slot will progress eastward into the CT valley region with surface temperatures rising 
to around the middle 70s /upr 70s to near 80 not out of the question 
but there is some uncertainty as to the time of clearing/. 
Clearing should progress into the central forecast area...but better 
confidence lies with the eastern region remaining socked in. 


Will be monitoring west for the evolution and severity of convection. 
It is plausible that western Massachusetts and S New Hampshire will see strong storms 
beginning around 6 PM. Feel the WRF-arw model is handling the 
outcomes this morning and into the afternoon very well and have been 
following it closely for the forecast. Anticipating a late show. Main 
threats will be gusty straight line winds with the possibility of 
large hail. 


&& 


Short term /6 PM this evening through 6 am Thursday/... 


Tonight... 
as mentioned scattered showers and thunderstorms may persist for a 
time during the evening as a result of the fairly steep middle level 
lapse rates. The activity should be pretty much over after midnight 
as a drier/cooler airmass works in behind the cold front. By 
daybreak...overnight lows should mainly be in the upper 40s and 
lower 50s. 


&& 


Long term /Thursday through Tuesday/... 


Highlights... 


* dry with moderating temperatures through Monday 
* showers possible Tuesday into Wednesday 


Overview and model preferences... 
16/00z model guidance suite remains in generally good agreement 
through early next week. Therefore confidence in the extended 
forecast remains higher than normal through early next week. 
Models are handling a transition from cutoff low pressure to the north to 
subtropical ridge dominating the pattern through at least Monday. 
There are a few details still to work out for Monday into the middle 
portions of next week...mainly because the ridge will gradually 
transition to more zonal flow as low pressure moves once again to the 
north. European model (ecmwf) still is a bit of an outlier in its attempt to bring low 
pressure up the East Coast Monday...and has flip-flopped on this scenario 
the last couple of runs. Therefore...will generally lean more 
toward the dry solution in GFS/gefs mean/CMC solution through Monday. Latter 
portions of the extended period are generally a low confidence 
forecast at this time due to much disagreement between available model 
data. See details below for handling of Monday night into middle week. 


Details... 


Thursday and Friday... 
high pressure will be building over the region from the west drawing 
cool northern airmass over southern New England through the period...but 
allowing the column to remain dry. 850 mb temperatures dip to +1 - +3c 
overnight Thursday night. Before increasing again to around +5c Friday. 
With high pressure beginning to crest over the area Thursday 
night...conditions look ripe for decoupling. So with rad cooling 
and inversion development...the cool 850 mb temperatures would promote some 
near freezing temperatures in northwest Massachusetts/southern New Hampshire so frost headlines are still a 
risk for Thursday night. Otherwise...temperatures in the middle to even upper 70s 
are possible with full mixing of the +5c temperatures during the day. 
Note that near coastal locations /including bos/pvd metros/ may be 
cooler due to sea breezes. 


Sat through Monday... 
high pressure will continue to dominate as upper level subtropical 
ridging builds over from the SW. Therefore...dry weather is expected to 
continue with gradually increasing temperatures. 500 mb heights increase to 
around 585dm by late sun...so a very warm airmass will be moving 
over the area as the high shifts slowly east. Therefore....expect a 
nice weekend with gradually warming temperatures in the upper 70s and 
even 80s possible sun and Monday. Note that again...near coastal 
locations may be a bit cooler due to sea breeze development. 


The only caveat will be a very weak shortwave that attempts to 
crest the ridge sun...which may provide a focus for some weak 
-shra activity in extreme western portions of the forecast area. 
However...soundings show a fairly good subsidence inversion that 
would need to be overcome. Therefore...will continue with a dry 
forecast...but its Worth at least mentioning. 


Monday night into middle week... 
the key for this portion of the forecast will be the handling of 
a transition from strong ridging dominating the forecast area...to more zonal 
flow aloft. Given that models are struggling with exactly how this 
breaks down...forecast confidence drops somewhat from late Monday 
into the middle week. At this time...with nearly zonal flow and strong westerly 
thermal wind...guidance favors the development of a stalled 
frontal boundary somewhere in the vicinity...but each model 
reaches this conclusion in different ways. European model (ecmwf) pushes it north from 
the middle Atlantic...while GFS suggests it approaches from the west. 
Gefs/ecens members are generally all over the place. Given 
this...will just transition forecast toward a more unsettled solution 
with more cloudiness and at least a slight threat for precipitation until 
these features become better resolved. 


&& 


Aviation /14z Wednesday through Sunday/... 


Forecaster confidence levels... 
low...less than 30 percent 
moderate...30 percent to 60 percent 
high...greater than 60 percent 


Overview... 
moderate confidence in tafs. IFR/MVFR conditions linger across most 
terminals into the morning this morning with a gradual improvement 
to VFR from west to east late this morning into this afternoon. Southeast 
mass/cape/islands may hold on to IFR/MVFR through tonight with 
moist ocean flow. 


Showers/isolated thunder will continue this morning especially close to 
the southeast New England coast. Otherwise...a few thunderstorms 
will be possible across the interior late this afternoon/evening 
with the cold front. 


Kbos taf...moderate confidence in taf. 
MVFR conditions hang on for a few hours this morning...but 
expecting a gradual lifting to VFR into the afternoon hours. A few 
showers are possible this morning and again late this evening. But 
thunder chances should stay mostly west and S of the terminal. 


Kbdl taf...high confidence in taf. 
IFR conditions this morning will improve to VFR late this morning 
or early afternoon. Exact timing is uncertain. A few 
thunderstorms maybe in the vicinity of the terminal late this 
afternoon/early evening but confidence is low. 


Outlook... 


Thursday through sun...high confidence. VFR. 


&& 


Marine... 


Moderate to high confidence. Showers and embedded thunderstorms 
across the southern waters should come to an end this morning. 
Areas of fog will also reduce visibilities below one mile at times 
this morning. Brief 25 to 30 knot wind gusts may occur through middle 
morning in any convection. Otherwise...winds will generally remain 
below Small Craft Advisory thresholds through tonight. However...Small Craft Advisory headlines for 
continue for all open waters through tonight. This a result of long 
southerly fetch with seas at or above 5 feet through tonight. Winds 
will shift to the northwest after midnight behind the cold front. 


Outlook...Thursday through Sunday 


Thursday into sun...high confidence. 
High pressure will build into region Thursday and is expected to crest 
over New England Sat and sun. Seas will gradually subside below 5 
feet Thursday with Small Craft Advisory/S ending. Afterwords winds and seas remain below 
Small Craft Advisory thresholds through the weekend...with sea breezes likely most 
days. 


&& 


Equipment... 


Buoy 44013 in mass Bay will be returned to service around June 
19th...pending weather conditions. 


&& 


Box watches/warnings/advisories... 


CT...none. 
Massachusetts...none. 
New Hampshire...none. 
Rhode Island...none. 
Marine...Small Craft Advisory until 9 am EDT Thursday for anz235-237- 
250-254>256. 


&& 


$$ 


Synopsis...Frank/doody 
near term...sipprell 
short term...Frank 
long term...doody 
aviation...Frank/doody 
marine...Frank/doody 
equipment...weather forecast office box