FXUS61 KBTV 100838
Area Forecast Discussion
National Weather Service Burlington VT
438 AM EDT Mon May 10 2021
Rain will come to an end this morning as surface low pressure
passes eastward into the Atlantic from the Jersey Shore.
Unsettled, showery conditions will continue through the
afternoon into Tuesday before a trend toward drier weather
occurs by Wednesday, and especially on Thursday and Friday.
Temperatures remain seasonably cool through Tuesday, then trend
milder toward the back half of the work week and into next
.NEAR TERM /THROUGH TUESDAY/...
As of 415 AM EDT Monday...Rain continues to track eastward across
southern Vermont as a surface low moves off the Jersey Shore and
into the Atlantic. Satellite imagery shows low-level dry air quickly
moving in behind it, allowing rain to come to an end around sunrise.
A cloudy morning is then in store with low temperatures in the 40s.
This afternoon, scattered rain showers are possible as daytime
heating paired with cool temperatures aloft allow for limited
instability. Said showers are likely to be terrain driven under west
to northwest flow. The limiting factor will be the aforementioned
low-level dry air, and the lack of robust day-time heating under
mostly cloudy skies. High temperatures today will be in the mid 50s
to low 60s. Convective rain showers will wane later this evening as
daytime heating, and thus instability, is lost. During the overnight
hours, however, a shortwave trough will pass overhead, supplying
added moisture and a chance of rain across northeastern Vermont.
Tuesday morning low temperatures will feel a bit chilly, in the mid
30s to low 40s, as colder air is advected in from the northwest. At
the same time, another push of low-level dry air is expected which
may allow for some clearing skies early in the day. Similar to
Monday, limited instability is expected to develop during the
daytime hours on Tuesday which will again lead to scattered rain
showers during the afternoon and evening. The difference, however,
is that there will be better synoptic support with the upper-level
low passing overhead during the day on Tuesday. In addition,
slightly cooler temperatures aloft will supply a bit more
instability; therefore, isolated thunder is possible Tuesday
evening, mainly across northern New York. The challenge will again
be overcoming the low-level dry air. The better moisture from the
upper low doesn`t look to arrive until late Tuesday, at which time
there will be better chances for precipitation.
Winds will be fairly breezy on Tuesday, with gusts up to 25 mph
possible given the steep lapse rates. Chilly temperatures will
persist throughout the day with highs in the upper 40s to mid 50s.
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 421 AM EDT Monday....Large scale synoptic pattern supports
mid/upper lvl trof acrs the ne conus on Tues night into Weds,
with potent 5h vort exiting our fa by 12z Weds. However,
additional s/w energy and associated mid lvl moisture lobe wl
impact our central/northern VT mtns on Weds aftn with more
scattered showers possible. Have continued with likely pops from
00z to 06z Weds, as gfs/nam and ecmwf show good synoptic scale
forcing with 5h vort, axis of enhanced 850 to 500mb rh, and
favorable northwest upslope flow of 25 to 30 knots at 850mb.
Have highest pops acrs the northern dacks into the
northern/central Green Mtns of VT. Have noted progged 850mb temp
<0C, while 925mb hover btwn 1-2c on Tues night, supporting some
light snow accumulation possible above 2500 feet overnight. Have
up to an inch at summit level overnight, based on thermal
profiles and available moisture. Weds wl feature more clouds
than sun, as northwest flow aloft prevails with linger mid lvl
moisture and embedded energy impacting central/eastern VT. Have
continued with chc pops for central/northern VT, including the
NEK. Progged 850mb temps near 0c and 925mb values btwn 5-7c,
support highs mid 50s to near 60F most locations on Weds, with
lows generally in the mid 30s to mid 40s for both Tues and Weds
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 421 AM EDT Monday...A relatively quiet period of wx
anticipated with no large scale or widespread precip events
expected. However, the chcs for aftn showers wl increase on
Friday and again Saturday and Sunday, as s/w energy in the flow
aloft, combines with some sfc instability and mid lvl moisture
to produce the threat. Have noted CAPE values btwn 500 and 800
j/kg on Sat and Sunday aftns on the ecmwf, so a few rumbles of
thunder are possible, but widespread rainfall is not likely,
given limited forcing and pw values <0.50. I have a feeling as
weekend becomes closer, areal coverage of precip wl become less
and mainly focused over the trrn, given the dynamics/moisture
associated with northwest flow. Have mention chc pops 25 to 35%
btwn 18z and 00z for Fri/Sat and Sun aftn/evening time frame. A
minor warming trend continues in the temp department with highs
starting in the upper 50s to mid 60s, warming into the 60s to
near 70 by Friday into next weekend. Overall, northwest flow
aloft wl keep the warmest and deeper moisture profiles to our
south, along with the best instability.
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
Through 06Z Tuesday...VFR expected at most sites through the 24
hour aviation forecast period. Exception will be RUT and SLK
where some MVFR ceilings are possible through 12z due to showers
moving into the area. Visibility will remain VFR. After 12z,
VFR conditions are expected at all terminals as showers come to
an end. Rain showers will then re-develop after 18z, but will
be scattered in nature. Isolated thunder is possible.
Therefore, have VCSH in the TAF for all terminals generally
between 18z and 03z Tuesday. Winds will be light through the TAF
period, northerly at 4-8 knots becoming westerly after 18z at
Tuesday: VFR. Numerous SHRA, Isolated TSRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Chance SHRA.
Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. Slight chance SHRA.