951 
fxus61 kbtv 050356 
afdbtv 


Area forecast discussion 
National Weather Service Burlington Vermont 
1156 PM EDT Friday Jul 4 2008 


Synopsis... 
high pressure will dominate the weather over the north country for 
the weekend. A weak low pressure system will move into the area on 
Monday for a chance at precipitation. The next chance for 
precipitation after that will be midweek next week as a cold front 
moves over the region. 


&& 


Near term /through Saturday/... 
as of 926 PM EDT Friday...quiet weather on tap for the overnight 
hours as surface high pressure settles across Vermont and 
northern New York. Satellite imagery shows shows high clouds 
spilling into southern sections of the forecast area. These are 
associated with a vorticity maximum riding along a nearly stationary front 
positioned just off the New England coast...and expect the cloud 
cover to remain through most of the night. As such...upped the 
sky cover to partly cloudy south and mostly clear all other 
locations. Also tweaked min temperatures up a bit in the cloudier areas 
due to loss of good radiational cooling. Otherwise...the going 
forecast looks good and no other changes needed. 


&& 


Short term /Saturday night through Sunday night/... 
as of 100 PM EDT Friday...nice weather continues into Saturday as 
aforementioned surface high bridges atop region. Mean 850 hpa temperature 
analysis would suggest maximum temperatures some 3-5 degrees warmer than 
today/S readings...generally from the u70s to l80s most areas under 
light flow around 5kts. Have generally downplayed any threat of 
clouds/low chance precipitation south per model/sref analysis...suggesting any 
activity should remain well south of our area along the southern 
New England coastal areas. 


Thereafter...clr/calm conds Sat night to give way to a few more 
clouds/relative humidity by Sunday as aforementioned surface high pushes slowly east 
and light southerly return flow brings increasing humidity to the 
region. Have maintained prior forecast idea of a slt/low chance for a 
shower or stray storm by the afternoon/evening hours based off available 
surface instability and terrain induced lifting...but most areas should 
remain dry with best threat across the higher terrain of southern 
dacks/ern/srn Vermont. 


&& 


Long term /Monday through Friday/... 
as of 245 PM EDT Friday...look for middle Summer conditions Monday 
and Tuesday with 850mb thermal ridge in place /+17 to +18c/. A 
weak shortwave trough at 500mb tracking eastward combined with 
insolational heating may be sufficient for a few afternoon showers and 
thunderstorms each day...especially across S-central/central Vermont 
during the afternoon and evening hours on Monday. Based on present trends...it 
appears that Valley High temperatures will reach the middle to upper 
80s...with low 80s in the 1-2 kft elevation band both Monday and 
Tuesday...with surface dewpoints in the middle 60s...and possibly near 
70f in a few spots. On Wednesday...a cold front is expected to 
track from west to east across the north country bringing several 
hours of increased cloudiness and a period of widespread shower 
and thunderstorm activity. It/S too soon to predict whether any of 
the convection will reach severe limits...but sufficient surface 
heating in advance of the front will bring that possibility. 
Timing of the front will be critical...and we will continue to 
monitor trends in nwp guidance over the next few days. 


Cooler temperatures and lower humidity is expected Thursday and 
Friday with just a chance of a daytime shower with shallow 
instability. The air mass should support high temperatures generally 
in the 70s...with a few upper 60s over northestern Vermont and the northern 
Adirondacks of New York. 


&& 


Aviation /04z Saturday through Wednesday/... 
through 00z Sunday...a ridge of surface high pressure extending 
from the Great Lakes region eastward across northern New England 
will continue to provide the north country with VFR clear skies and 
light winds. Only exception to be development of locally dense 
radiation fog overnight at mpv and slk. Fog will disperse around 
by 13z with return of daytime heating...and southerly winds less 
than 10 kts redevelop. 


00z Saturday through Wednesday... late Sat through sun...VFR except 
areas of MVFR S-central Vermont with chance -shra and a slight chance of a 
thunderstorm Sunday afternoon through Sunday evening. 


Monday...areas of MVFR with scattered daytime showers and 
thunderstorms Monday afternoon. Otherwise...VFR. 


Tuesday...mainly VFR. 


Wednesday...possible showers and thunderstorms with cold frontal 
passage areawide. Areas of MVFR and local IFR conditions possible. 


&& 


Equipment... 
the ASOS at Massena (kmss) is inoperative...only altimeter is 
being reported. Technicians are aware of the problem. In 
addition...the Massena ASOS will be out of service from Tuesday 
July 8 through July 17 as Concrete work begins on the sensor 
foundations. 


&& 


Btv watches/warnings/advisories... 
Vermont...none. 
New York...none. 


&& 


$$ 
Synopsis...jn 
near term...mb 
short term...jmg 
long term...banacos 
aviation...Hanson 
equipment...btv