Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
255 am EST Thursday Nov 26 2015
gusty south winds and mild temperatures will continue across the
region through Friday ahead of an advancing cold front pushing
east from the Great Lakes states. The front will swing through the
region later Friday afternoon into Friday night with scattered to
numerous showers. Behind the front a return of mainly dry and
seasonable weather is expected for the upcoming weekend and into
early next week. Additional energy will likely affect the area by
the middle of next week, though with moderating temperatures most
of the precipitation will likely fall as rain.
Near term /through tonight/...
as of 255 am EST Thursday...mainly a persistence forecast through
sunrise Friday as variable middle to high cloudiness traverses the
region along with gusty south to southwesterly winds. 500 meter
back-trajecory analysis from this morning's National oceanic and atmospheric administration hysplit model run
shows our air this afternoon traces its source to the Delaware-Maryland-Virginia
region yesterday which saw high temperatures in the lower to middle
50s. Feel similar readings will be achieved by later today in the
Champlain and St Lawrence valleys, with slightly cooler values (45
to 50) across the Adirondacks, and especially eastern Vermont
where a greater maritime influence will occur. On the winds, gusts
should easily climb into the 15 to 25 knot range by afternoon if
not sooner, a result of a tight pressure gradient between strong
maritime high pressure and an approaching Great Lakes upper
trough. So despite the mild temperatures it will feel on the
blustery side in many spots today.
By tonight more of the same as thickening middle to high cloudiness
occurs in advance of the upper trough and its attendant cold front
approaching from the northwest. However, deeper moisture and
dynamical lift along the front remain to our north and west so dry
conditions will continue. With occasionally gusty south flow
continuing overnight temperatures will hold nearly steady across
much of the area, generally holding in the 40s to around 50.
Short term /Friday through Saturday/...
as of 321 PM EST Wednesday...increased pressure gradient remains
for Thursday night keeping winds brisk out of the south. This will
help to keep min temperatures fairly mild...40s. A cold front approaches
from the west on Friday...with rain showers reaching the north
country Friday afternoon. Low pressure system passes well to our
north. Temperatures on Friday will also be mild ahead of the cold
front...50s. Conditions will also remain breezy ahead of the front
on Friday. Cold front will finally cross our area Friday
night...mainly rain showers expected with just a quick change over
to snow showers as the precipitation is ending towards early Saturday
morning. Min temperatures Friday night will be much cooler...generally
upper 20s and lower 30s...coldest temperatures north and west where the
front passes first.
Long term /Saturday night through Wednesday/...
as of 321 PM EST Wednesday...some upslope snow showers on
Saturday as region is under northwest flow following cold frontal
passage which occurred overnight. General surface high pressure
will then be over our area through early Tuesday morning. GFS and
European model (ecmwf) both show some sort of Great Lakes low pressure system to
then impact the northeast in the Tuesday night into Wednesday
timeframe. Right now that is very far out in the forecast. Right
now looks like some rain showers are expected for the middle of
the week with generally near normal temperatures through the
Aviation /08z Thursday through Monday/...
through 12z Friday...VFR through the period. Low level wind shear and increasing
southerly wind gusts to be the primary aviation concern for the
Expect generally clear skies below 200 above ground level through 12z with just
thickening high clouds. Winds trending southerly at all terminals
overnight (occasionally gusty at kbtv/kpbg) and increasing after
12z with gusts into the 15 to 28 knots range. Some low level wind shear possible at
kslk through 12z. After 18z ceilings remain VFR though gradually lower
into the 080-150 above ground level range under continued gusty south flow.
Outlook 06z Friday through Monday...
06z Friday through 18z Friday...VFR under high pressure.
18z Friday through 18z Saturday...trending to MVFR in rain
showers as a cold front drops south into the region from Canada.
Some MVFR/IFR in snow showers possible 00z-18z Saturday as
18z Saturday through 00z Tuesday...VFR conditions expected as
another ridge of high pressure builds into Vermont and northern
as of 255 am EST Thursday...
a lake Wind Advisory remains in effect today...
Modestly strong and gusty south winds of 20 to 30 knots are
expected on the lake today and will likely continue into tonight
before slowly abating on Thursday. The highest winds to generally
occur across the central and northern portions of the lake where
significant wave heights will range in the 2 to 4 foot range with
a moderate chop. Bays and inlets with open southerly exposure will
also see waves on the higher end of the forecast range. These
conditions will pose a hazard to small craft operating on the lake
over the next 24 hours.