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fxus61 kcar 081916 
afdcar 


Area forecast discussion 
National Weather Service Caribou ME 
316 PM EDT Friday Aug 8 2008 


Synopsis... 
low pressure will lift across the state tonight and continue to 
move northeast of the area on Saturday. A weak ridge of high 
pressure will follow for Saturday night into Sunday. Another low 
pressure will approach the region Monday and cross the state 
Monday night. 
&& 


Near term /through Saturday/... 
rain continues to fall across western portions of the forecast 
area this afternoon. Models lift this area of rain across the 
remainder of our forecast area this evening as low pressure over 
western New England moves eastward. Have categorical probability of precipitation across 
most of central and northern sections tonight, however models have 
not handled the movement and intensity of the rain very well so 
far so my confidence in the probability of precipitation not high. Even though 2 to 3 
inches of rain have fallen just west of our forecast area, model 
quantitative precipitation forecast indicates rainfall amounts will remain below an inch for 
tonight as rainfall intensity weakens. Stable middle level lapse 
rates will prevent thunderstorm activity tonight. 


Low pressure will exit to the east Saturday morning, however upper 
trough will remain across the state. With daytime heating and 
troughing aloft, expect scattered showers to develop during the 
day on Saturday. Cape values between 500 and 1000 joules indicate 
scattered thunderstorms possible across the region Saturday 
afternoon. 
&& 


Short term /Saturday night through Monday/... 
weakening surface low pressure is expected to drift to the north 
into the Maritimes at the beginning of this period. At the same 
time a strong upper level low pressure system will approach from 
the Great Lakes. Another developing surface low pressure system is 
expected to accompany the upper low. Both the surface and upper 
system are expected to move across the state Monday. With the NAM 
and GFS similar with use a model blend approach for pop...sky 
cover and quantitative precipitation forecast. For pop and quantitative precipitation forecast will combine sref...nam12 and 
gfs40. For sky cover have used NAM/GFS combination. Will use gmos 
for dew point...wind and temperature. Will include mention of 
thunder for Sunday and Monday afternoons. Not a lot of instability 
but may be some problems with approach of upper system. Will also 
include patchy fog in early morning for both days. 
&& 


Long term /Monday night through Friday/... 
a low pressure system will be center over the County Warning Area at the start of 
the long term...it will move into New Brunswick Canada early Tuesday 
morning. With high pressure building in behind it. The surface 
high will giveway as an upper level low transits through the area. Wednesday 
evening and Thursday morning. High pressure will ridge in early 
Friday and will dominate through the end of the period. The European model (ecmwf) 
and GFS are in general agreement at the beginning of the 
period...but diverge quickly. Loaded gmos and adjusted sky and pop 
so they supported one another. Current long term grids most 
closely follows the GFS from Wednesday night forward. 
&& 


Aviation /19z Friday through Wednesday/... 
showers moving across the region will produce a wide variety of 
conditions across the taf sites tonight. Generally VFR on Saturday 
but lower conditions in any scattered showers or thunderstorms. 
Short term: expect periods of IFR/MVFR with showers and low clouds expected 
Saturday night through the day Monday. 
&& 


Marine... 
near term: used a blend of the nam12 and GFS for winds and wnawave 
for seas. Winds and seas to remain below Small Craft Advisory levels through Saturday. 


Short term: have initialized the wind grids with a 50/50 blend of 
the nam12 and the gfs40. With very weak pressure gradient over the 
region and models showing history of high bias will lower speeds 
slightly. For waves: grids initialized with the wna. Wave heights 
look reasonable with long period incoming waves dominating over 
local wind wave. Only adjustment will be to keep maximum height at 
3 feet. Will keep patchy fog in forecast. 
&& 


Car watches/warnings/advisories... 
ME...none. 
Marine...none. 


&& 


$$ 


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