135 
fxus61 kcar 211930 
afdcar 


Area forecast discussion 
National Weather Service Caribou ME 
330 PM EDT sun Mar 21 2010 


Synopsis... 
a weak stationary frontal boundary will remain across central 
Maine tonight. The boundary will move south across downeast on 
Monday. Low pressure will track off of Cape Cod on Tuesday and 
move through the Gulf of Maine on Wednesday. 
&& 


Near term /through Monday/... 
the start of the short term finds the models in good agreement. 
An upper level system will move through the area overnight. 
Higher pressure will ridge into the region tomorrow as a low 
tracks across central Quebec to the north of the area...and a 
deepening low over northern Georgia and its associated frontal system 
continue to track toward the East Coast. By the end of the period 
the over Canada will continue to move east. The low over Georgia 
will move north to southern PA. The GFS/Gem bring the warm front into 
downeast ME by the end of period. The European model (ecmwf) brings the warm front to 
southern ME by the end of the period. 


Extremely dry conditions across northern ME today will reduce any 
potential precipitation north of Houlton. A blended quantitative precipitation forecast brings around 
15 through the hul area and .10 into pqi. Knocked back quantitative precipitation forecast north 
of hul by about .05 inch. Kept around an .15 inches for 
hul...about a half for pqi and car. 


Loaded maximum/min with match guidance. Blended sky/pop/wnd with 
nam12/GFS/MOS guidance. Blended quantitative precipitation forecast nam12/GFS/HPC guidance. Did 
not like any of the guidance for deep...carried over from previous 
forecast. 
&& 


Short term /Monday night through Wednesday/... 
used a blend of the NAM and GFS for the short term forecast. 
Frontal boundary will become stationary across downeast Monday 
night keeping the threat of scattered showers through Monday 
evening. Models in good agreement with low pressure moving off of 
Cape Cod Tuesday and tracking through the Gulf of Maine on 
Wednesday. Precipitation associated with the warm air advection 
with this system will spread from south to north across the 
forecast area late Monday night reaching northern sections by 
noontime Tuesday. All models in fairly good agreement with 
critical thickness moving quickly northward during Tuesday 
providing mainly rain for coastal areas to the Houlton area with a 
mix bag for northern and northwest sections and the Central Highlands. 
A possible mix of snow and sleet over northern Penobscot and 
southern Aroostook counties may occur with the onset of the 
precipitation Tuesday. Used the precipitation from thickness tool with a blend 
of the NAM and GFS for thickness to produce the weather grids. Too much 
uncertainty still to have a lot of confidence in amounts but first 
prediction would be a couple of inches of snow across northwest 
sections and the Central Highlands with the possibility of some 
light ice accumulation also. Elsewhere, any snow or ice 
accumulation appears to be light with rain being the primary 
precipitation type. As low pressure moves east of the region on 
Wednesday, northerly winds will wrap colder air across northern 
sections with a changeover to snow and some additional snow 
accumulation possible. Total quantitative precipitation forecast amounts will range from just 
under two inches along the coast lowering to around three quarters 
on an inch across the north. This may cause some flooding concerns 
across the region Tuesday night into Wednesday especially across 
Central Highlands. 
&& 


Long term /Wednesday night through Sunday/... 
used the gmos for the extended. As low pressure moves east of the 
region, brisk northwest winds will follow with scattered snow 
showers for Wednesday night. Brisk conditions to continue into 
Thursday. Alberta clipper will approach the region Thursday and 
move across the state Thursday night under strong northwest winds 
and a return to more winter like temperatures into the weekend. 
&& 


Aviation /18z Sunday through Friday/... 
near term: VFR conditions this evening dipping down to MVFR in snow for 
car...pqi...and hul. Light rain for bgr...bhb poss mixed with snow 
over night. MVFR conditions to improve to VFR early tomorrow morning. 
And hold through the day. Decreasing clouds heights for bhb and 
bgr tomorrow afternoon as the next system approaches from the 
southeast. Conditions will lower to IFR from south to north across 
the region Monday night into Tuesday. Conditions will slowly 
improve to VFR Wednesday night into Thursday. 
&& 


Marine... 
near term: no issue in the marine through the near term portion of 
the forecast. An approaching system from the southeast will begin to increase 
the winds and build the seas tomorrow afternoon. 


Short term: gale conditions possible Tuesday into Tuesday night as 
low pressure moves through the Gulf of Maine so will keep gale 
watch going. Used a blend of the nam12 and GFS for winds and 
wnawave for seas. 
&& 


Car watches/warnings/advisories... 
ME...none. 
Marine...gale watch from Tuesday morning through late Tuesday night for 
anz050>052. 


&& 


$$ 
Near term...Norton 
short term...Foster 
long term...Foster 
aviation...Norton 
marine...Norton/Foster