000
FXUS61 KBTV 190537
AFDBTV
AREA FORECAST DISCUSSION
National Weather Service Burlington VT
137 AM EDT Tue Mar 19 2019
.SYNOPSIS...
Quiet and seasonably cool weather continues through Tuesday
night as surface high pressure settles atop the region.
Temperatures moderate by Wednesday into Friday as a surface
front and developing offshore low pressure bring renewed chances
for rain and snow shower activity.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 137 AM EDT Tuesday...Weak shortwave trough continues to
move across the area early this morning. System is mainly
producing clouds...but there are a few snow showers associated
with it. This activity should move out of the area by about
sunrise. Have tweaked forecast to account for this scenario.
Rest of forecast remains unchanged.
Previous Discussion...
Persistence the name of the game over the next 42 hours as
strong surface high pressure builds across the northeastern
third of the nation leading to quiet weather conditions.
Shallow, instability-driven cumulus will produce a scattered
mountain flurry here or there through sunset this evening, and
again on Tuesday. Otherwise dry weather remains in the forecast
under clear to partly cloudy skies and light winds. Temperatures
to remain seasonably cold, bottoming out from 10 to 18 above in
the broad valleys overnight while higher terrain ranges from 5
below to 10 above. Highs on Tuesday just a tad warmer than today
(30s) followed by teens to lower 20s Tuesday night with some
variability.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 300 PM EDT Monday...Shortwave ridging will bring a fairly
quiet period of weather to the North Country during the
daylight hours on Wednesday. Skies will gradually increase in
cloud coverage as flow aloft begins to switch to the southwest
which will allow some moisture to advect into the region. As
this happens, temperatures aloft will warm as well which will
result in temperatures warming slightly above normal values with
readings in the 40s across our forecast area. Conditions will
begin to deteriorate late Wednesday night as a sharpening upper
level trough dives south toward New England. This will bring
some rain and snow showers into North New York, mainly the St.
Lawrence Valley, prior to sunrise heading into Thursday.
Shower activity will overspread the North Country Thursday with a
mix of rain and snow expected throughout the day. Based on the
timing of the CAA associated with both a frontal passage and a
switch to northwesterly flow aloft, Thursday should still be an
overall seasonable day with temperatures generally climbing into the
low to mid 40s. During the morning hours, a 40 kt jet, give or take
a couple knots, will be in place across the North Country which
would initially limit rain/snow in the Champlain Valley with
downsloping winds helping to limit moisture. However, by Thursday
afternoon this jet will exit eastward and allow the Champlain Valley
to get in on some of the rain/snow action. Overall snowfall amounts
would be very minor on Thursday with little to no snow accumulation
in the Champlain and St. Lawrence Valleys with up to an inch
possible elsewhere.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 300 PM EDT Monday...Models continue to diverge on the
potential of a coastal low developing west of benchmark late
Thursday night into Friday morning. This is completely different
than the runs yesterday which yields some uncertainty to the
extended forecast. Looking at both NAEFS and GEFS members, most
perturbations show a feature developing near benchmark and
quickly sliding east. However, some perturbations and
deterministic runs of the FV3 and ECMWF show this feature
curling back in near Cape Cod which could bring significant
snowfall to the Green Mountains. At this time, this appears to
be the least likely scenario with the Canadian, SREF and GFS all
showing a more progressive system sliding eastward.
Nevertheless, it looks like some snow showers will be possible
on Friday as the trough axis swings through the region with a
nice shortwave tracking through the region. Snow accumulations
once again appear very minor with limited moisture to work with.
This weekend could be very nice, especially if the GFS, SREF and
Canadian models end up closer to the low track on Friday. As it
stands, it looks like the trough from Thursday and Friday will be
very progressive and quickly slide off to the east with high
amplitude ridging building into the region for the weekend. This
would yield clearing skies with seasonably cool temperatures on
Saturday followed by near normal temperatures and sunny skies of
Sunday. The period of nice weather would likely continue into Monday
with the chance for some isolated showers during the afternoon hours
as we remain under northwesterly flow aloft.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...Upper level disturbance moving across
the area early this morning will bring some clouds and light
snow showers to the area through about 10z...but VFR conditions
are expected. VFR conditions are expected for the remainder of
the period...but a few snow showers are possible this afternoon
at KSLK. However...visibilities will remain in the VFR category.
Winds will be less than 10 knots through the period.
Outlook...
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. Chance SHSN, Chance SHRA.
Thursday: Mainly MVFR and IFR, with areas VFR possible. Chance
SHRA, Likely SHSN.
Thursday Night: Mainly MVFR, with local IFR possible. Chance
SHSN, Chance SHRA.
Friday: MVFR/IFR conditions possible. Chance SHRA, Chance SHSN.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHSN.
Saturday: Mainly VFR, with local MVFR possible. Slight chance
SHSN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...JMG
NEAR TERM...Evenson/JMG
SHORT TERM...Clay
LONG TERM...Clay
AVIATION...Evenson
|
