Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
350 am EDT Friday Jul 3 2015
the combination of surface high pressure and plenty of dry air
aloft will produce mostly sunny skies today. A few clouds are
possible in the northern New York and Vermont with temperatures
warming into the 70s. Another cool night is expected tonight with
increasing clouds toward morning. A few showers are possible on
Saturday especially across central and southern Vermont...with
temperatures in the 70s to near 80.
Near term /until 6 PM this evening/...
as of 350 am EDT Friday...water vapor shows large area of
subsidence across our County Warning Area...while a ribbon of middle level moisture
associated with weak vorticity in flow aloft approaches northern New
York. This will produce a few clouds...but given deep dry layer not
expecting any precipitation. After a chilly start with areas of valley fog
this morning...temperatures will quickly warm into the u60s mountains to upper
70s warmer valley with prognosticated 850 mb temperatures between 7-9c. Light
terrain/thermally driven winds this morning will become northwest to
west at 5 to 10 miles per hour today. Overall a beautiful day expected with
plenty of sunshine...pleasant temperatures...and low relative humidity values.
Short term /6 PM this evening through Sunday/...
as of 350 am EDT Friday...have made some changes with
regards to the forecast on Saturday into Sunday...which features
more clouds and increased chances for rain showers. Latest trends in
the models has been for southern stream system to track further
north on Saturday. Models are struggling with how to handle northern
stream energy dropping down across the northern Great Lakes...while
plenty of convection associated with southern stream vorticity is
located over the MS valley. This energy and moisture will streak
northeast tonight...before getting sheared out to our south on
Saturday night from approaching northern stream trough.
However...latest trends show deeper 850 to 500mb moisture
impacting our central/southern County Warning Area...along with some enhanced 850
to 700mb upward vertical velocities. Given deep dry layer in place across our
County Warning Area...thinking initial surge of moisture/lift will fall apart
across our southern forecast area on Saturday afternoon. Have noted a strong rrq
of 25h jet lifting across southern Canada...which will help pull
precipitation north. Given dynamics and latest trends I will mention low
likely probability of precipitation southern Rutland/Windsor counties and taper off to chance
central and schc near the international border on Saturday. Quantitative precipitation forecast
will be light and generally <0.10" across our southern County Warning Area.
Another change with more clouds expected on Saturday will be
slightly cooler temperatures...expecting highs mainly in the 70s.
On Saturday night into Sunday...additional northern stream energy
impacts our northern County Warning Area. Once again moisture profiles are
limited...but 500 mb vorticity is pretty potent. Will mention schc to low chance
probability of precipitation across the northern mountains on Sat night into Sunday associated
with this system. Quantitative precipitation forecast will be light given the lack of deep layer
moisture. Middle/upper level ridge builds into our forecast area by 18z
Sunday...resulting in clearing skies and warming temperatures. Prognosticated 850 mb
temperatures warm between 12-14c by 00z Monday...supporting highs in the middle
70s mountains/nek to lower 80s cpv.
Long term /Sunday night through Thursday/...
as of 350 am EDT Friday...a very questionable and fluid forecast
period with a hint of Summer then perhaps a return to a June
Short wave ridging Sunday night-Monday admist a split flow aross NE
Continental U.S. Then the approach of northern stream system along with
interaction from a upper trough as part of the split flow will
likely bring showers/thunderstorms and rain threat Tuesday afternoon through Wednesday. Frontal
boundary appears it may try to hang up across New England as
indicated yesterday and wpc guidance suggests. Therefore...can't
rule out threat of showers through end of the week.
Slightly above normal temperratures and dry early then a return to
seasonable levels. No heat wave as along as we stay dominated by
northern cyclonic flow which is being suggested through next week.
Aviation /08z Friday through Tuesday/...
through 06z Saturday...VFR conditions will prevail through period
with the one exception being potential IFR conditions for
kslk/kmpv and MVFR conditions for for kbtv/kmss around 07z-11z
due to fog/stratus. Conditions will not persist and will clear
rapidly for all stations. Winds for the period will remain light
and variable before becoming westerly at 05-10 knots this afternoon.
Outlook 06z Saturday through Tuesday...
VFR with weak surface high pressure...except for possible MVFR/IFR in
fog/br at mpv/slk between 06z and 12z Friday night. Uncertainty on
shower potential this weekend...with latest trends showing the
potential for additional showers being limited through the weekend
and confined to the higher terrain.