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Area forecast discussion 
National Weather Service Taunton Massachusetts 
423 PM EDT Tuesday Mar 16 2010 


Synopsis... 
high pressure building over the region will bring fair dry weather 
for the rest of the week and for the weekend. Another cold front 
will likely bring a period of rain showers later Sunday and Monday. 


&& 


Near term /until 6 am Wednesday morning/... 
high pressure surface and aloft over the plains and rockies. Low 
pressure surface and aloft over the Maritimes. Northwest flow from 
Manitoba Canada into New England with much of the flow aimed toward 
Maine and Nova Scotia. 


Lingering 20-25 knot gustiness late afternoon in eastern mass...but 
with a diminishing pressure gradient we should see winds becoming 
light everywhere tonight. The northwest flow shows mostly clear skies 
with patchy cirrus in central Canada. 


NAM and GFS show a shortwave in the northwest flow approaching New 
England later tonight. Limited moisture...mostly limited to the 
cirrus level as it crosses our area late tonight. 


Min temperatures are a blend of MOS. 


&& 


Short term /6 am Wednesday morning through Wednesday night/... 
continued dry northwest flow through the period. 


Wednesday...lingering high clouds in the morning as the upper 
shortwave moves past. Otherwise a fine day with light westerly winds. 
NAM and GFS bring mixing to about 4000 feet. This seems low 
considering full sun and a west flow...mixing should reach closer to 
850 mb away from the South Coast where the marine layer will buffer 
some of the warming. Temperatures at 850 mb will be around 2c...which would 
support maximum temperatures around 63f...used the metnam guidance with minor 
adjustments. 


Wednesday night...continued dry with light winds. Some increase in 
clouds possible especially northern mass/southern New Hampshire as a weak front 
moves into northern New England. Min temperatures are from a blend of MOS. 


&& 


Long term /Thursday through Tuesday/... 
fairly quiet weather expected in the long term. One exception to 
this will be Sunday into Monday when a cold front is expected to 
move through southern New England. 


Thursday through Saturday...a weak cold front will move through the area 
Thursday night with high pressure building in behind. With very dry 
low level air in place...precipitation is unlikely to develop...so should 
be mostly a wind shift. Temperatures will be 10 to 15 degrees above 
normal during the day with lows 5 to 10 degrees above normal. Used 
a blend of available guidance for temps/winds. 


Sunday and Monday...low pressure moving through southeastern Canada 
with a middle-level trough will pull a cold front through southern New 
England Monday morning. Expect a decent period of showers with this 
event. There is a strong low level jet over the area during this 
time as well as marginal instability which may lead to a period of 
gusty winds and thunder. Have kept thunder out of the forecast at 
this point since this is still pretty far out. Temperatures remain 
10 to 15 degrees above normal Sunday with near normal temperatures 
Monday. 


Tuesday...dry weather returns with cold high pressure. Temperatures 
fall slightly below normal. 


&& 


Aviation /21z Tuesday through Sunday/... 
tonight...VFR. High confidence. Diminishing north-northeast wind this 
evening....mainly cape and islands. 


Wednesday...VFR. High confidence. 


Wednesday night...VFR. High confidence. 


Outlook...Thursday through Sunday... 


Thursday through Saturday...high confidence VFR. Low confidence scattered MVFR 
conditions in diurnal cumulus clouds. 


Sunday...low confidence forecast. VFR conditions deteriorating to 
MVFR/IFR in rain showers. 


&& 


Marine... 
diminishing wind tonight and slowly diminishing seas tonight through 
Wednesday night. Lingering small craft strength wind gusts this 
evening...mainly south and east of Cape Cod. Seas will remain at or 
above 5 feet most of tonight...with 5 foot or higher seas on the 
outer waters through Wednesday night. 


Outlook...Thursday through Sunday... 


Thursday...small craft seas diminish through the day...otherwise 
light winds and clear weather. 


Friday and Saturday...quiet weather with high pressure overhead. 
Light winds and 1 to 3 foot seas expected. 


Sunday...seas and winds increase ahead of a cold front. Rain 
showers possible. 


&& 


Hydrology... 
area Flood Warning continue through 945 PM tonight for Rhode Island...eastern 
mass and southern New Hampshire as several of the smaller rivers and 
streams are still rising...and some remain in moderate to major flood 
severity. Numerous river flood warnings continue...with some forecast 
points at moderate and major flood severity. Please see flood 
warnings and statements for more specific information about the 
status of individual rivers. 


&& 


Box watches/warnings/advisories... 
CT...none. 
Massachusetts...none. 
New Hampshire...none. 
Rhode Island...none. 
Marine...Small Craft Advisory until 5 PM EDT Wednesday for anz232-235- 
237. 
Small Craft Advisory until 1 am EDT Wednesday for anz231-233- 
234. 
Small Craft Advisory until 6 am EDT Thursday for anz250-251- 
254>256. 


&& 


$$ 
Synopsis...wtb/rlg 
near term...wtb 
short term...wtb 
long term...rlg 
aviation...wtb/rlg 
marine...wtb/rlg 
hydrology...