FXUS61 KBTV 250218
AREA FORECAST DISCUSSION
National Weather Service Burlington VT
1018 PM EDT Fri May 24 2019
Clearing skies will develop this evening, along with diminishing
winds as high pressure builds in from the eastern Great Lakes
region. The tranquil weather will only last through the first half
of Saturday. Thereafter, a warm front pushing in from southwest New
York will allow widespread showers to develop across the region from
west to east late in the afternoon or evening, into Saturday night.
Showers and possibly a thunderstorm or two will linger into Sunday
morning with a cold frontal passage, then drier conditions are
expected by mid to late afternoon. Monday will be dry with highs in
the 60s to around 70.
.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 1009 PM EDT Friday...Microphysics imagery off of GOES 16
is showing fog beginning to build in across the North Country as
skies have cleared. Saranac Lake is the only place reporting fog
thus far but over the next few hours fog will continue to
develop. Based on the observation in Saranac Lake, any fog that
does develop could be dense as visibilities have been bouncing
between a half and a quarter of a mile.
Previous Discussion...Low pressure continues to pull away from
the region this afternoon, moving south of Nova Scotia and out into
the Atlantic. Moisture associated with this system will likewise
exit to the east, with high pressure building across the North
Country tonight into Saturday. Hence, clouds will dissipate this
evening as we lose daytime heating. This with light winds will allow
for good radiational cooling; lows will be in the mid to upper 40s
for most, though the usual cold spots in the Adirondacks and
Northeast Kingdom will bottom out around 40. Clouds will increase
Saturday morning ahead of a warm front lifting in from the
southwest. Precipitation associated with the front will follow,
moving into our NY areas mid afternoon, and into Vermont late
afternoon into the early evening hours. Initially, warm air
advection aloft will keep us capped, so don`t anticipate any
thunderstorms through most of the daylight hours. Highs will range
from the upper 60s to lower 70s. Deep moisture plume will stream
northward into the region late tomorrow into tomorrow night ahead of
an approaching cold front. PWATs are progged to exceed 1.50 inches
from the Champlain Valley westward. Some elevated instability will
spread into northern NY, allowing thunderstorms to develop. These
will interact with the copious moisture and warm cloud depths of 10+
kft to produce heavy rain at times through the evening hours. The
best moisture and instability starts to get shunted to the southeast
after midnight as the prefrontal trough moves through, so the threat
will wane as we head toward sunrise Sunday morning. Rainfall totals
through Saturday night will be a third to around a half an inch in
Vermont, while some NY locations could see upwards of an inch.
Higher amounts will be possible in any convection. Overnight lows
will be in the 50s to around 60.
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 250 PM EDT Friday...Front clears through the area during
the morning to early afternoon hours on Sunday with little
fanfare. Maintained very low end pops (20-30%) for showers or an
isolated storm through the morning hours to account for any
scattered activity but forcing is rather weak along the wind
shift so most of the day should turn out dry with highs
seasonably mild in the 70s to locally near 80. Then trending
mainly clear Sunday night under building high pressure with lows
in the 40s to lower 50s.
.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 250 PM EDT Friday...H5 ridge then crests atop the region
on Monday with sunny skies and mild temperatures in the 60s.
This will be the best day of the workweek for outdoor
Thereafter the general wx trends unsettled as the forecast area will
reside on the northern edge of deep layer southeastern CONUS
ridging. Periodic shortwave wave passages embedded in fast west to
southwesterly flow aloft should ensure near daily chances of showers
and occasional storms, though inherent timing uncertainties in day 4-
7 forecasts leads me to keep pop values reasonable side (40-60%) at
this point. Best threat of storms looks, at least at this point to
occur on Wednesday into Thursday when the combination of heating and
moisture looks the greatest. Temperatures in general to average
within 5 degrees of late May seasonal norms.
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Through 00Z Sunday...Skies have finally trended VFR as the pesky
MVFR deck has finally mixed out of KSLK and KRUT. VFR conditions
are expected to continue for the most part through Saturday
morning before rainfall begins to enter norther New York.
Overnight, there will be some patchy fog which could impact KMPV
and KSLK given high dewpoints and recent rainfall which could
yield visibilities of 2 miles or less at times with ceilings
less than 1000 ft. The main timeframe for any fog development
would be between 05Z and 12Z. After 12Z, any fog will quickly
mix out as we should have ample sunshine to start the day.
Variable winds overnight will switch to the south in the morning
with gusty southerly winds developing around 16Z. Rainfall will
enter northern New York after 18Z and spread into Vermont
between 21Z and 22Z and bring some localized MVFR vsby in
heavier showers. There is also the potential for a few rumbles
of thunder but have opted to leave it out for the time being
given the lack of areal coverage expected.
Saturday Night: Mainly VFR, with local IFR possible. Chance SHRA,
Slight chance TSRA.
Sunday: Mainly VFR, with local MVFR possible. Slight chance SHRA,
Slight chance TSRA.
Sunday Night: VFR. NO SIG WX.
Memorial Day: VFR. NO SIG WX.
Monday Night: VFR. Slight chance SHRA.
Tuesday: Mainly VFR, with local MVFR possible. Likely SHRA.
Tuesday Night: Mainly MVFR, with local IFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday: Mainly MVFR, with areas IFR possible. Chance SHRA,