Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
146 am EDT Tuesday Jul 7 2015
a weakening upper air disturbance over the Middle Atlantic States
will bring clouds and more humid conditions along with a chance of
showers and thunderstorms to the region on today. A cold front
will move into the region tonight bringing showers and
thunderstorms to the north country. A high pressure area will
build east from the Great Lakes Wednesday afternoon and will
remain over the north country for the remainder of the
week...bringing cooler and drier weather to the region.
Near term /until 7 am this morning/...
as of 127 am EDT Tuesday...forecast on track with mostly clear
skies and temperatures ranging from the middle 50s to upper 60s. See little
change in temperatures for the rest of the night. Lots of low clouds now
streaming up the lower Hudson Valley and Berkshires will likely
overspread the region by morning. Can't rule out an isolated
shower developing as area of high precipitable water of 1.7 to
1.9" surges into the region.
Short term /7 am this morning through Wednesday night/...
as of 415 PM EDT Monday...a weakening upper air disturbance over
the Middle Atlantic States this afternoon will bring clouds and
increasing moisture into the region on Tuesday...with dew points
climbing into the middle to upper 60s. Surface based convective available potential energy climb to
500 to 1300 j/kg by late Tuesday afternoon. 0-6 km bulk shear over
the region is only 20-25 knots on Tuesday...with wet bulb zero
values around 12000 to 13000 feet...so not expecting any severe
thunderstorms on Tuesday. Storm Prediction Center only has the forecast area in a
general thunderstorm outlook for Tuesday...and this seems
reasonable. BUFKIT forecast soundings have precipitable water
values climbing to 1.5 to 2 inches on Tuesday and early Tuesday
night...so some locally heavy rainfall is possible. Have gone with
just chance probability of precipitation for Tuesday...as feel showers and thunderstorms
will be scattered in nature during the day on Tuesday. Have gone
with likely probability of precipitation for Tuesday as the cold front moves into the
12z model runs have trended faster with the movement of the cold
front...with any residual showers Wednesday morning across Vermont
and the Champlain Valley coming to an end by middle to late morning.
Models showing middle level dry slot over the region by 18z
Wednesday...so expecting a dry forecast from Wednesday afternoon
into Wednesday night as a ridge of high pressure builds east from
the Great Lakes.
Long term /Thursday through Monday/...
as of 321 PM EDT Monday...a nice stretch of dry Summer conditions
is expected for the majority of the long term as the north country
is generally dominated by surface high pressure. Zonal flow across
the northern Continental U.S. Thursday becomes a bit more anti-cyclonic
moving into Friday and Saturday as deep middle-level subsidence sets
up over the southeast Continental U.S. With an upper ridge developing over
the upper Midwest and Great Lakes regions. This will result in
prevailing partly sunny/cloudy skies across the btv County Warning Area Thursday
through Saturday along with seasonal temperatures, highs in the
70s/80s and lows in the 50s/60s. By Sunday the ridge retrogrades
westward allowing more troughiness to set up across the northeast,
deepening southward into the middle-Atlantic on Monday. Several
pieces of embedded shortwave energy will renew chances for showers
and thunderstorms Sunday afternoon and again on Monday with temperatures
remaining near normal.
Aviation /06z Tuesday through Saturday/...
through 06z Wednesday...VFR conditions expected for the rest of
the evening before isolated convection starts to pop around the
area. Clear skies overnight will give way to building clouds as
light warm air advection will bring low and middle level moisture in
from the middle Atlantic. This will lead to some potential for MVFR
low stratus at rut/mpv/slk/mss. As the first surge of energy moves
into the area expect some isolated showers to develop across the
forecast region so without being able to nail down specific
locations I just included mention of vcsh. However there could be
some ts embedded in the rain showers around the taf sites. The
timing for these pop-up showers will be from around 14z through
19-22z. Then there will be a break were we will see some
scattering and short lived clearing before the main front drops
down into the north country late this evening bringing a second
and better chance for widespread rain showers. Anticipate light
and locally variable winds this evening becoming south/southwest
on Tuesday from 10-15 knots with gusts 15-22 knots.
Outlook 06z Wednesday through Saturday...
00z Wednesday - 18z Wed: VFR/MVFR. Periods of rain showers with chance thunderstorms and rain.
18z Wednesday - 00z Sun: VFR. Early morning IFR fog possible at
ktyx radar will be out of service until Tuesday or later.
equipment...weather forecast office btv