FXUS61 KBTV 190509
Area Forecast Discussion
National Weather Service Burlington VT
109 AM EDT Thu Jul 19 2018
High pressure building over the region continues to bring dry
and seasonable weather through the end of the week. A chilly
night is anticipated tonight with lows in the mid 40s to mid
50s. Temperatures return to above normal values by the end of
the week, along with increasing chances for rain showers by
.NEAR TERM /UNTIL 2 PM THIS AFTERNOON/...
As of 104 AM EDT Thursday...No significant changes made to
current forecast as all elements are within thresholds. SLK
already down to 40f, thinking mid 30s looks reasonable for them
with mainly low/mid 40s to low/mid 50s elsewhere with some
Large ridge of surface high pressure will continue to ridge
into the North Country overnight, and crest over the area on
Thursday during the daytime hours. This results in dry and quiet
weather for our area through the near term. Tonight we will
have clear skies and light winds, and temps will drop quickly
following sunset. With sharp low level thermal inversions in the
coldest pockets of the Dacks and Northeast Kingdom, the coldest
spots will drop into the upper 30s. Most of our area will have
low temps bottoming out on the mid 40s to mid 50s, around 60
closer to Lake Champlain. Some spots should still hit cross over
despite afternoon dewpoints dropping into the 30s now,
especially Saranac Lake area. Think it will generally be some
patchy fog in some of the typically fog prone spots. Dry weather
will continue on Thursday with almost a repeat day of today.
Surface high will crest overhead on Thursday, so winds will be a
bit lighter than Wed. Anticipate mostly sunny skies Thursday,
generally upper 70s to lower 80s. Thursday night will also be
dry and clear, with mainly light winds. High pressure begins to
slide eastward though, so not as cold as tonight, temperatures
will generally be in the mid 40s to mid 50s.
.SHORT TERM /2 PM THIS AFTERNOON THROUGH FRIDAY NIGHT/...
As of 332 PM EDT Wednesday...High pressure will continue to be
the primary influence for Friday`s weather with dry conditions
prevailing. Thicknesses will continue to rise and 925mb temps
will climb to about 23C. This will translate to high
temperatures in the upper 80s across the St. Lawrence/Champlain
Valley with 80s elsewhere, excepting the higher mountain areas
where highs will be in the 70s. Friday night lows will be warmer
than Thursday night as southerly winds slowly increase the
dewpoint. Expect lows in 50s across the Adirondacks and in the
Northeast Kingdom and upper 50s/lower 60s across the valleys.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 332 PM EDT Wednesday...After another dry day on Saturday,
high pressure will begin to yield to a large upper low digging
from the Dakotas into the Ohio River Valley. Heights will begin
to fall as the upper low approaches, but the upper low begins to
meander as it becomes cut-off. Forecast depictions of the
dynamical tropopause beautifully show the stratospheric air and
the associated PV anomaly induce stronger southerly flow ahead
of the upper low and influence the development of a surface
feature along the east coast. The upper low weakens into an open
wave as it barely moves across the area with our CWA also
positioned at the periphery of an anomalously strong Bermuda
This will lead to an enhanced stream of moisture with
disturbances cycling northward ahead of the upper low. The first
passes nearby on Sunday with a surface feature and a warm front
that gets dragged northward. Some uncertainty regarding this
feature remains with the latest GFS, ICON, and FV3 runs sending
the disturbance further eastward, which will likely keep the
best precipitation chances to our east with the initial surge of
moisture. Not much instability is currently forecast with the
first system on Sunday with the main forcing mechanism being the
developing warm front and isentropic upglide. So no mention of
thunder there for now. From there, the unsettled weather pattern
will continue through at least Wednesday with the weakening
upper trough replaced by a new upper trough, helping to maintain
moist, southwesterly flow. There will be some instability, so
storms can be expected Monday through Wednesday, with the
greater chances during the daylight hours.
Temperatures will remain above average, especially overnight
low temperatures. Somewhat cooler conditions are expected Sunday
as southeasterly flow brings in some cooler maritime air and a
warm front is lifted northward. Temperatures will then warm
again Monday with Tuesday and Wednesday looking similar to
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
Through 06Z Friday...Aviation challenge this morning is fog/br
potential at slk/mpv and mss. Sfc analysis shows 1020mb high
pres axis from the central Great Lakes into northern NY with
light winds and clear skies. This has allowed temps to fall
quickly with slk approaching their cross over temp of 39f.
Thinking some patchy fog with ifr conditions likely btwn 08-11z
at slk, but conditions will probably bounce up and down, given
the lack of significant boundary layer moisture. At mpv thinking
just a very small window near sunrise for ifr in br, as
temp/dwpt spread is still 3 degrees. Meanwhile, kmss received
0.34 of rainfall two days ago, and thinking with little spread
in temp/dwpt some intervals of light fog is possible toward
sunrise. Have utilized tempo for mvfr conditions at mss.
Otherwise...vfr conditions prevail on thursday with light winds.
Friday: VFR. NO SIG WX.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. Chance SHRA.
Sunday: Mainly VFR, with areas MVFR possible. Chance SHRA.
Sunday Night: Mainly VFR, with areas MVFR possible. Chance SHRA.
Monday: Mainly VFR, with areas MVFR possible. Chance SHRA, Chance