Area Forecast Discussion
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FXUS61 KBTV 290546
Area Forecast Discussion
National Weather Service Burlington VT
146 AM EDT SUN MAY 29 2016
The Memorial Day weekend will continue to see well above normal
temperatures with daytime max temps between 10 to 20 degrees
above normal. Increasing low level moisture will allow for higher
relative humidities and an increasing chance for widespread
showers with scattered thunderstorms possible on Sunday and
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 142 AM EDT Sunday...No significant changes needed to
current forecast, with warm conditions continuing late this
evening (temps mainly in the low-mid 70s at 10pm). With the 2pm
observation in Burlington we reached 90 degrees for the second day
in a row putting us two thirds of a way to a local heat wave.
Expect warm and moderately humid conditions through the overnight
period. Despite some aftn and early evening towering Cu across
the higher terrain, anticyclonic flow aloft with strong mid-level
ridge in place across NY/New England precluding any convective
initiation with lack of large-scale forcing for ascent.
Anticipate some patchy fog/mist across the valleys of northern NY
after midnight tonight, similar to what occurred during the pre-
dawn hrs this morning. Lack of rainfall in recent days will
generally limit areal extent of fog formation. Overnight low
temperatures generally in the low to mid 60s.
For Sunday, mid-level shortwave trough crossing the Eastern Great
Lakes induces height falls by afternoon across Northern NY/VT,
with better chance for afternoon shower and thunderstorm
development as compared to the previous 2-3 days. There will be a
large influx of precipitable water with values rising to 1.6-1.8".
925mb temps are elevated again Sunday and the 21-23C 925mb temps
will support max temps tomorrow once again in the upper 80s to low
90s. Currently the forecast for Burlington reaches heat wave
criteria with a max temps of 90 expected. Should remain dry with
partly to mostly sunny for the morning hours, then will see
scattered shower/thunderstorm development mainly after 17-18Z,
with initial development likely starting across the Eastern slopes
of the Adirondacks and moving Eastward into the Champlain Valley
and into Southern VT, per 18Z NAM4KM. MUCAPE values are expected
to reach 1000-2000 J/kg during the peak daytime heating hours.
With the chance for thunderstorm development, slow storm motions,
and PWAT values 1.6-1.8", continued to mention the chance for
heavy rain in any thunderstorms that develop. We should be safe
with regards to flash flooding owing to how dry we`ve been in May
but locally heavy downpours and dangerous cloud to ground
lightning can be expected with the scattered convective storms
expected Sunday afternoon into early Sunday evening.
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
As of 427 PM EDT Saturday...precipitable water values early
Sunday night will be 1.5 to 2 inches. Will mention showers and
thunderstorms for Sunday night, and will include some heavy
rainfall possible with any thunderstorms. Conditions quite dry
across the region in May, so do not expect any flash flood issues
at this time. ECMWF and GFS models now showing frontal system will
move through the region earlier in the day on Monday with showers
mainly Monday morning, as both models showing a mid level dry slot
will move into the region by 18z Monday. Thus, have decreased pops
for Monday afternoon, and will go with a dry forecast for Monday
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 427 PM EDT Saturday...Fair and dry weather will be over the
north country from Tuesday through Thursday night, as a ridge of
high pressure at the surface and aloft builds east from the Great
Lakes. ECMWF and GFS models in fairly good agreement with bring a
cold front from the Great Lakes into the region with showers
expected Friday and Friday night. ECMWF and GFS models differ on
forecast for Saturday, with the ECMWF model more progressive than
the GFS and has a mainly dry forecast for Saturday, while the GFS
model has the front stalled across the region on Saturday as it
will be parallel to the upper flow. Thus, forecaster confidence
for the Saturday forecast is low at this time. Have stuck with
super-blend pops for Saturday and will have a chance of showers in
the forecast for Saturday.
.AVIATION /06Z Sunday THROUGH Thursday/...
Through 06z Monday... Generally VFR with overnight IFR/LIFR mist
at SLK and possibly at MPV. Increasing risk for sct SHRA/TSRA
particularly after 16z Sunday at our NY terminals.
Similar to last night with some leftover high clouds. Areas of
mist likely starting at 06z at SLK. Boundary- layer flow is
slightly higher enough at mpv to keep any mist that may develop
there temporary. Winds initially light/terrain driven becoming
Any mist/light fog lifts early in the morning under strong
sunshine. Additional heating and increasing depth of moisture
should support at least scattered showers/possible storms. Latest
short-term guidance points to a start time around 16z off the
Adirondacks and then advancing eastward. Any thunderstorm capable
of heavy rain and associated brief IFR visibilities. Maintained
VCSH for this period with prevailing VFR conditions. Winds
becoming south/southwest 5-8 kts.
Outlook 06z Monday through Thursday... Mainly VFR with daily
chances for showers and thunderstorms each afternoon and evening.
Greatest coverage/threat appears to occur in the Monday early
evening time frame. Best chance for a dry day will be Wednesday.
Record maximum temperatures for Saturday 5/28 and Sunday 5/29 are as
BTV - Burlington 92 in 1978 89 in 1978
MPV - Montpelier 88 in 1978 87 in 1978
MSS - Massena 89 in 1978 90 in 1978
St Johnsbury 93 in 1978 92 in 1978
Mt Mansfield 77 in 1978 77 in 1978