Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
139 PM EDT Friday Mar 27 2015
a low pressure system will be slow to exit the region today
leading to a quiet weather pattern over the next couple of
days...but not before occasional light snow today with minor snow
accumulations. Drier air this weekend will lead to a return of
below normal temperatures. At the beginning of next week another
low pressure system will bring a weak cold front through the
forecast region leading to a chance of precipitation on Monday.
Near term /until 8 PM this evening/...
as of 139 PM EDT Friday...areal coverage of precipitation
beginning to decrease just a bit and feel we can just mention
isolated to scattered rain or snow showers for the rest of the
afternoon. Remainder of forecast in real good shape.
Short term /8 PM this evening through Sunday/...
as of 351 am EDT Friday...it remains a broken record but the
upper level trough will be quite slow to actually clear the New
England region and will still be trying to hold on this evening.
As the trough does move the east we will see a return of northwest
flow and continued cold air advection as a surface high pressure
system builds into the area. This will result in clearing skies
and cold dry weather over the weekend. Expect maximum temperatures on
Saturday to be in the middle to upper 20's across the Saint Lawrence
and Champlain Valley and only rising to the teens in elevations
above 2000 feet. Overnight lows on Saturday night/Sunday morning
will drop into the middle teens in the valleys with the typical cold
spots dropping into the single digits. By Sunday the high pressure
system centered over the Carolinas will slowly drift offshore
leading to a return of warmer southerly flow. That will cause
temperatures on Sunday to rebound into the middle to upper 30s across most
of Vermont and northern New York.
Long term /Sunday night through Thursday/...
as of 331 am EDT Friday...a progressive middle-upper level flow
pattern is anticipated through the extended forecast period...with
temperatures continuing slightly below average and an absence of
any significant precipitation systems. A few minor troughs/low
pressure systems embedded in west-northwest flow expected...with main light
precipitation potential late Sunday night into Monday...and again
during the daylight hours on Thursday.
Northern stream shortwave trough...with main surface low passing
to our north will bring increasing clouds followed by scattered
light snow showers late Sunday night. Overall moisture is limited
with this system...so generally looking at a dusting to 1-2" of
snow...with higher amounts generally at or above 1000ft. May see a
few rain showers during the day Monday as surface trough shifts
eastward across the north country. Lows Sunday night generally in
the middle-upper 20s...with temperatures warming into the upper 30s to
lower 40s for Monday afternoon.
Generally looking at a northwesterly middle-level flow pattern Tuesday and
Wednesday. Next shortwave trough/clipper type system is expected
to pass just to our south and west during the day Tuesday. May see
a period of increasing cloudiness...and also carried 20-30 probability of precipitation
across northern New York zones for Rain/Mountain snow showers as best differential
positive vorticity advection passes by during Tuesday afternoon. Highs on Tuesday generally
in the middle 30s across the Adirondacks...to upper 30s to lower 40s
elsewhere. Generally fair Tuesday night...Wednesday...and
Wednesday night with narrow ridge of surface high pressure
expected across the northestern Continental U.S. Into Quebec. Looking at overnight
lows generally in the 20s...and highs on Wednesday in the upper 30s
to lower 40s.
Middle-tropospheric flow becomes zonal to west-southwesterly on Thursday with
warm/occluded front passing from west to east across the region.
This likely brings another period of cloudy skies and light
rain/snow showers. At this point...significant quantitative precipitation forecast appears
unlikely. Highs on Thursday again near to slightly below climatology
norms...with afternoon readings generally in the low-middle 40s.
Aviation /18z Friday through Wednesday/...
through 18z Saturday...region is under northerly flow with upper
trough still upstream of the area. Overcast skies are in place across all
of our terminals...with variable ceiling heights and flight
categories. Expect all sites to improve to at least MVFR by about
00z...then VFR by about 06z. Winds will strengthen overnight and
remain gusty tomorrow. There may be some isolated snow showers
overnight...but other than vcsh at slk have not mentioned it at
Outlook 18z Saturday through Wednesday...
18z Saturday through 00z Sunday...areas of MVFR central/eastern Vermont
with isolated snow showers. Otherwise...VFR.
00z Sunday through 00z Monday...VFR/mostly clear with high
pressure in place.
00z Monday through 00z Tuesday...low pressure moving eastward
from the Great Lakes brings light snow or rain shower activity
with periods of MVFR cigs/vsby. May see a brief period of S-SW
wind gusts 25kts 06-12z Monday in advance of approaching low
00z Tuesday through Wednesday...mainly VFR conditions
expected...but some MVFR possible in showers late Tuesday...mainly
across the Adirondacks/slk.