682 
fxus61 kbox 072053 
afdbox 


Area forecast discussion 
National Weather Service Taunton Massachusetts 
353 PM EST Sat Nov 7 2009 


Synopsis... 
high pressure south of New England will bring mild and dry 
conditions through early next week. A cold front will move across 
southern New England late Tuesday or Tuesday night...bringing a 
brief shot of colder weather and the chance of showers. High pressure 
and milder weather looks to return for late week and into next 
weekend. 


&& 


Near term /until 6 am Sunday morning/... 
northern stream shortwave tracking east across southeast Canada will send a 
weak front through southern New England late tonight. Moisture is limited so this 
will be a dry frontal passage with main effect to bring a period of middle 
clouds overnight. Mav temperatures accepted...with temperatures mostly in the 30s 
away from the immediate coast. 


&& 


Short term /6 am Sunday morning through Sunday night/... 
southern New England will be on the northern periphery of building southeast US middle level 
ridge Sunday and Sunday night with surface high pressure in control. It 
will be a beautiful day Sunday with mosunny skies...generally light 
winds and temperatures well above normal. Used a mav/met blend which 
brings temperatures into the low to middle 60s. 


Clear with light winds Sunday night with high pressure overhead. Temperatures 
were a mav/met blend. 


&& 


Long term /Monday through Saturday/... 
a blend of the 12z European model (ecmwf)...GFS ensemble...and HPC guidance was utilized 
for this forecast...with the most weight given to the European model (ecmwf). 


It looks as through the long term period will start off with a couple 
of fantastic November days featuring dry mainly dry weather and well 
above normal temperatures. On Monday...southwesterly flow and mostly 
sunny skies should result in maxes a good 10 to 15 degrees above 
normal. 


A cold front will approach southern New England from the northwest on 
Tuesday. At this time...we are a little bit unsure of the exact 
timing...but the 12z European model (ecmwf) seems like a good fit at this time. 
Therefore...will forecast warm southwesterly flow and highs near 70 
in a lot of places Tuesday before the front sweeps across late 
afternoon or evening. I wouldn/T be completely shocked to see some 
locations top out in the 70-75f range if skies remain mostly cloud- 
free for a good portion of the day and the front doesn/T come through 
as fast as the NAM is showing. 


We have a low chance of showers just ahead of and along the front 
from northwest-southeast late Tuesday afternoon and evening. 


For the Tuesday night through Thursday time frame...we preferred the 
European model (ecmwf) as highlighted above. The 12z operational GFS looks to be 
overamplifying the northern stream short wave...and then merges 
whatever is left of Tropical Storm Ida with that northern stream wave 
for the Wednesday-Thursday time frame. This results in a monster coastal storm 
with hurricane force winds and blinding snowfall for parts of 
southern New England during this time...but that solution is being 
discounted. 


Instead...we go with the frontal passage for Tuesday night with high 
pressure moving in for the Wednesday-Friday time frame. A brief cold shot with 
below normal temperatures and windy conditions should be experienced on 
Wednesday before temperatures warm again for the the of the week and into 
next weekend. For now...we are playing the forecast dry for Wednesday-Sat 
period. 


We will still keep an close eye on the midweek forecast...as more 
amplification in the pattern may result in a more interesting 
scenario than what we currently have going...but not likely to the 
extreme as the 12z GFS. 


&& 


Aviation /21z Saturday through Thursday/... 
tonight...VFR. A brief period of broken middle clouds possible in the 
interior. Low probability of patchy late night IFR fog CT valley. Low probability 
low level wind shear coastal terminals as 35-40 knots low level jet develops ahead of the cold 
front. 


Sunday and Sunday night...VFR with mostly clear skies. 


Outlook /Monday through Wednesday/... 


Mainly VFR conditions are expected through the period. A cold frontal 
passage is foreseen for late Tuesday and Tuesday evening. This may bring a 
brief shot of MVFR ceilings/visibilities in showers...followed by gusty 
northerly winds Tuesday night and Wednesday. 


&& 


Marine... 
tonight...we issued Small Craft Advisory for most waters except bos 
Harbor...Narragansett Bay and Cape Cod Bay. A period of g25 knots 
likely as 35-40 knots low level jet develops across the waters. Low level 
inversion will prevent stronger winds from mixing down but should 
see a few g25 knots. We trimmed wnawave guidance due to normal high 
bias in SW flow events. 


Sunday...winds shifting to west and diminishing to less than 15 knots. 
Lingering 5 feet seas possible over outer southern waters. 


Sunday night...light winds and seas as high pressure builds over the 
waters. 


Outlook /Monday through Thursday/... 


Gradually increasing southwesterly flow will be seen ahead of a cold front 
Monday and Tuesday with mainly sub-Small Craft Advisory conditions expected. A cold 
front will sweep across the waters Tuesday evening. Northerly Small Craft Advisory 
winds and building seas are foreseen in the wake of the front for Tuesday 
night and Wednesday with a chance of low-end gale gusts. Winds and seas 
then subside for Wednesday night through Thursday as high pressure moves 
in. 


&& 


Box watches/warnings/advisories... 
CT...none. 
Massachusetts...none. 
New Hampshire...none. 
Rhode Island...none. 
Marine...Small Craft Advisory from 8 PM this evening to 5 am EST Sunday 
for anz232>235-237-250-251-254>256. 


&& 


$$ 
Synopsis...kjc/mle 
near term...kjc 
short term...kjc 
long term...ekster 
aviation...kjc/ekster 
marine...kjc/ekster