567 
fxus61 kgyx 090827 
afdgyx 


Area forecast discussion 
National Weather Service Gray ME 
327 am EST Friday Jan 9 2009 


Synopsis... 
high pressure will gradually build into the region from the west 
today and tonight and will crest over the area on Saturday. Low 
pressure moving east out of the Ohio Valley Saturday evening will 
pass out to sea southeast of Cape Cod on Sunday. A weak ridge of 
high pressure will build over the area Sunday night. A cold front 
will slowly approach from the west on Monday. Low pressure will 
form on this front by Tuesday morning and this low will track 
through southern New Hampshire and Maine on Tuesday. High pressure 
will build over the region on Wednesday. Low pressure will move 
out to sea well south of New England on Wednesday night and 
Thursday. 


&& 


Near term /through today/... 
another breezy and cool day on tap for northern New England. Middle 
level trough....though not as sharp as yesterday....will result in 
variable cloudiness bubbling up down wind of the mountains by 
afternoon. Not quite the instability of yesterday so think any 
snow shower activity will be mainly confined to mountain zones. 
Colder air will continue to flow into the region with high 
temperatures topping out about ten degrees cooler than yesterday. 


&& 


Short term /tonight/... 
weak ridge of high pressure will continue to build into the area 
from the west overnight. Expect clearing skies with variable clouds 
probably hanging on in the mountains till after midnight. 
Northwest gradient will also diminish after midnight. Looking for 
sub zero readings in the mountains and single numbers for much of 
the south. 


&& 


Long term /Saturday through Thursday/... 
surface ridge of high pressure moves across the forecast area Saturday then out to 
sea Saturday night. Low pressure moves east from the Ohio Valley to the 
middle Atlantic coast Saturday night then out to sea Sunday...tracking 
S of the 40 north latitude...70 west longitude benchmark for heavy snow 
in our forecast area...thus not anticipating heavy snow unless models track 
the system further north over subsequent runs. At this time open upper 
level trof, fast moving weak low that doesn't dr0p below 1000 mb until 
Sunday at 18z when event winds down and with forecast area under dry cold air 
regime at the start of the event expect this to be a mostly light 
snow event /no rain or mixed prcp expected/ with highest 
accumulations over our most southern zones where could end up being 
an advisory event with a 3 to 6 inch snowfall. Too early to 
pinpoint snow amounts exactly at this time for a 4th into 5th period 
event. HPC snow forecast matches well with gfs40 quantitative precipitation forecast and snow to water 
ratio of 13 to 1. 


Once this low moves out to sea we will see a winter pattern 
persist with mostly below normal temperatures and a risk of a couple light to 
maybe moderate snow events. On Tuesday a weak warm air advection 
pattern sets up at 800 mb under a digging 500 mb trough and developing surface 
low. Could see some light accumulating snow from this system. This 
system intensifies as it moves by leaving US with cold blustery 
conditions for Tuesday night. Another upper level trough digs eastward for 
Thursday developing a better organized surface low with a low forming 
at the 800 mb level which provides a better scenario for accumulating 
snow. Too early to pinpoint track, snow amounts, et cetera at this time. 


Generally used the gfs40 and mav MOS for Saturday through Sunday then 
gmos for the rest of the long term forecast. 


&& 


Aviation /07z Friday through Tuesday/... 
short term...VFR with some MVFR ceilings in the mountains today 
through tonight. 


Long term /Saturday through Tuesday/...low passing to our S then 
out to sea Saturday night and Sunday morning likely to bring -sn or 
snow to the forecast area with IFR to possibly LIFR conditions. Low pressure 
moving east to the East Coast on Tuesday may bring MVFR to IFR 
conditions in -sn. 


&& 


Marine... 
short term...Small Craft Advisory in effect through this 
afternoon. This may have to be extended through the evening hours 
but will let the day shift look at the new data and make this 
decision. 


Long term /Saturday through Tuesday/....sfc low tracking to our S 
and out to sea Saturday night and Sunday could bring Small Craft Advisory conditions 
to the waters and possibly gales to the outer waters on Sunday. 
Another low approaches from the west on Tuesday and could bring Small Craft Advisory 
conditions with a chance of gales behind the system as it intensifies 
over the Maritimes Tuesday night. 


&& 


Gyx watches/warnings/advisories... 
ME...none. 
New Hampshire...none. 
Marine...Small Craft Advisory until 6 PM EST this afternoon for 
anz150>154. 


&& 


$$