706 
fxus61 kbtv 200537 
afdbtv 


Area forecast discussion 
National Weather Service Burlington Vermont 
137 am EDT Wednesday Aug 20 2008 


Synopsis... 
the frontal system which produced widespread precipitation across 
the area over the past 24 hours...will continue to push southeast 
and away from the region off the northeastern Seaboard. Surface high 
pressure building in from the Great Lakes states will settle across 
the northeastern quarter of the nation over the next 4 days...providing 
fair and dry conditions to the region along with a warming trend. 
The next chance of significant precipitation is not expected until 
this coming Sunday when a cold front approaches the region. 


&& 


Near term /until 6 am this morning/... 
as of 829 PM EDT Tuesday...quiet...cool...crisp conditions tonight as 
cool Canadian high pressure builds into area. Not many updates 
needed this evening as forecast is in good shape. Did increase 
cloud cover a bit through midnight as upslope stratocu deck is 
hanging on over northern New York and Vermont. Still believe areal 
extent of coverage will decrease to mostly clear skies after 
midnight as drier 850-700mb air moves into the area. There is a 
chance for some patchy fog to develop tonight in sheltered 
valleys...but areal extent will be limited due to rather strong northwest 
gradient tonight that will inhibit fog formation. Temperatures rather 
cool and generally ranging through the 40s...though colder into 
the upper 30s portions of the NE kingdom and middle to upper 30s 
dacks where potential of patchy frost will exist in colder 
hollows. On the flip side...locally milder readings in vicinity of Lake 
Champlain where water temperatures remain near 70f. 


&& 


Short term /6 am this morning through Thursday night/... 
as of 254 PM EDT Tuesday...ideal stretch of late Summer weather on tap to 
round out the work week as aforementioned surface high settles across 
the northestern U.S. With mainly clear skies and light winds expected. 
Will attempt to show slightly wider than normal diurnal temperature trends 
across the area through the period...which appears reasonable given 
such dry boundary layer moisture profiles. As mean columnar flow backs to 
southerly by Thursday...expect a marked warming trend to 
occur...with temperatures rebounding quickly to near or slightly above 
climatological values by the afternoon hours. This trend to continue 
into the extended. 


&& 


Long term /Friday through Tuesday/... 
as of 400 PM EDT Tuesday...the long term concern will be chances for 
rain shower/thunderstorm late Saturday into Sunday...followed by temperatures. 
Overall...models in very good agreement with middle/upper level ridge 
of high pressure across our County Warning Area through Saturday. This ridge will provide forecast area 
with blw normal precipitation and above normal temperatures going into next 
weekend. BUFKIT soundings and moisture profiles show very dry 
airmass across our forecast area...which will support a large spread in diurnal 
temperatures from daily highs to overnight lows. Prognosticated 850 mb temperatures between 
15 and 17c on Friday...along with 1000-500 thickness value >570dam 
support highs well into the 80s for both Friday and Saturday. 
Given low level thermal profile and several days of good low level 
drying...would not be surprised if a few temperatures approach 90f on 
Friday across the deeper valley locations. Late Saturday through 
Sunday...mid/upper level trough deepens across the central Great Lakes 
as surface cold front moves across our County Warning Area. Once again...weak pre frntal 
trough and embedded 500 mb vorticity in the SW follow aloft will interacting with 
surface instability to produce chance probability of precipitation late Saturday. The actually 
surface front...along with best middle/upper level dynamics/moisture will 
impact forecast area on Sunday...with a chance of showers/storms. Given...quick 
movement of system...expect only a 1 to 4 hour window of precipitation. 
Temperatures behind the boundary will cooler to near normal levels for 
Monday into Tuesday...with mainly dry conditions. The interaction 
of Tropical Storm Fay being lifted north toward the Ohio Valley and 
Middle Atlantic States ahead of next digging middle/upper level trough will 
have to be watched closely for latter next week. 


&& 


Aviation /06z Wednesday through Sunday/... 
through 06z Thursday...high pressure will continue to build into 
the region overnight. The net result will be VFR conditions with 
generally clear skies and light winds. However...due to near 
surface moisture from rainfall in the past 24 hours...some 
localized areas of fog should develop...especially in the kmpv 
and kslk areas. Fog should lift by 13z and then VFR conditions 
will exist all areas for the remainder of the period. Northwest 
winds will develop between 13z and 16z with gusts in the 10 to 16 
knot range. Winds will subside around 00z to light and variable. 


06z Thursday through Saturday...mid/upper level ridge of high pressure 
and associated surface high pressure will build into our taf sites and 
provide VFR conditions through Saturday. The potential will be for 
morning fog to develop at mpv/slk between 06-12z...with vlifr 
conditions possible. 


&& 


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


&& 


$$ 
Synopsis...jmg 
near term...Dumont 
short term...jmg 
long term...Taber 
aviation...evenson/Jan