076 
fxus61 kgyx 231453 
afdgyx 


Area forecast discussion 
National Weather Service Gray ME 
953 am EST Monday Nov 23 2009 


Synopsis... 
as high pressure moves into the Canadian Maritimes...an easterly 
flow will continue through tonight. A middle Atlantic low pressure 
system will remain offshore as it moves northeast Tuesday and 
Tuesday night. A weak ridge of high pressure moves across the 
region on Wednesday and slips offshore on Thanksgiving day. 
Another middle Atlantic low pressure system on Thursday night 
slowly moves through northern New England Friday and Saturday... 
then moves into the Maritimes on Sunday. 


&& 


Near term /until 6 PM this evening/... 
the forecast problem for the rest of the day will be the extent 
of the clouds. 


Latest visible images show a sheet of stratus/stratocumulus moving 
northwest...as moisture gets trapped under the inversion shown on 
the 1200 UTC gyx sounding. The morning sounding showed the 
inversion close to 2500 feet...and interestingly the clouds are 
getting to the mountain valleys...but are not making it to the 
higher terrain. 


The visible images also shows breaks over the ocean...where it 
appears as though the inversion is not as strong. Extrapolation 
would bring these breaks to the coast late this morning and this 
afternoon. Several 0000 UTC/0600 UTC mesoscale models also show 
this trend. Because of this...there may be breaks near the 
coast...and the overall cloud cover was lowered there. 


Also...it appears as though the high terrain may be able to escape 
the moisture under the inversion (as the mountains look to be above 
the inversion). Morning soundings showed convective temperatures 
in the middle 40s...so cumulus development looks possible there this 
afternoon. 


Watching moisture streaming northwest across central and southern 
New England in the low to middle level isentropic lift ahead of a 
weak surface wave well to the southeast. It appears as though most 
of this will pass south of the area this afternoon. Maintained a 
mention of showers for southern zones this afternoon as they could 
be clipped by this activity. 


Morning soundings suggest highs will only reach the lower to middle 
40s. Based on the cloud over in place...nudged down highs for all 
areas outside of the mountains. 


&& 


Short term /6 PM this evening through 6 am Tuesday/... 
continued onshore flow should yield increased low clouds with 
a chance of showers as well as some drizzle and fog...especially 
over southern/coastal sections. 


&& 


Long term /Tuesday through Sunday/... 
tough call on timing of the moisture exiting our region from the 
offshore low. NAM holds onto clouds and plenty of moisture longer 
than the GFS Tuesday night. Split the difference...keeping chance 
probability of precipitation over southern portions of the forecast area during the 
evening...then ending any chance for precipitation. 


Held off on any probability of precipitation for next coastal system until Thursday. Both 
the GFS and Euro model suggests an inland track across New Hampshire with 
this one. This will keep the precipitation mainly in the liquid form until 
enough cold air can wrap into the system over the weekend. 


Strong easterly gradient forms by Friday...however...astronomical 
tides appear to be relatively low at this time. 


Yet another inland storm passes west of the region during the 
midweek (next week) hours. 


&& 


Aviation /15z Monday through Friday/... 
in the near term /rest of today/...ceilings are hovering around 
3000 feet at most terminal locations this morning. Visible images 
show breaks over the ocean...reaching near the coast. The 1200 gyx 
sounding shows a top inversion level of close to 3200 feet...but 
this may not be indicative off what is occurring over the ocean. 


Most mesoscale models show The Breaks over the ocean making to the 
coast this afternoon. This may be overdone...but it appears as 
though all terminals will hover at the MVFR/VFR Break Point for 
the remainder of the day. 


In the short term /tonight/...MVFR to IFR conditions area wide 
due to clouds and chance of showers as well as some fog/drizzle 
tonight. 


Long term...plenty of low clouds with patchy fog through Tuesday 
evening...followed by clearing. Ceilings and visibilities lower for a 
substantial time with approach of next coastal system late in the 
week. 


&& 


Marine... 
in the near term /rest of today/...winds are starting to increase 
as the gradient tightens between strong high pressure over Nova 
Scotia and a weak wave of low pressure over the middle Atlantic. 
Starting to see gusts near small craft levels at iosn3...and this 
may necessitate moving up the timing of the Small Craft Advisory 
for anz154 if trends continue. 


Otherwise...the gradient will slowly increase as the weak wave 
moves up along a low level baroclinic zones southeast of the 
waters. This will bring winds and seas close to small craft levels 
over the ocean late this afternoon. 


In the short term /tonight/...Small Craft Advisory conditions due to seas tonight. 


Long term...Small Craft Advisory to continue into Tuesday. 


&& 


Gyx watches/warnings/advisories... 
ME...none. 
New Hampshire...none. 
Marine...Small Craft Advisory from 7 PM this evening to 6 PM EST 
Tuesday for anz150>154. 


&& 


$$