Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KBTV 260730
Area Forecast Discussion
National Weather Service Burlington VT
330 AM EDT Fri Aug 26 2016
Deep moisture along with a weak wave of low pressure aloft will
produce variable clouds along with the chance of a passing shower,
mainly south tonight into Friday morning. Behind this system a
return to dry, late summer warmth is expected for Friday afternoon
into Saturday of the upcoming weekend. The next chance of showers
will occur by Sunday afternoon into Sunday night with another weak
front, followed by more warm and dry weather for early next week.
.NEAR TERM /THROUGH TONIGHT/...
As of 1259 AM EDT Friday...Based on satellite imagery have
tweaked the sky grids to better reflect current situation of
generally clear skies in Vermont and more noticeable cloud cover
in New York. This sharper gradient of clouds should lead to more
fog development over Vermont given clear skies...light winds...and
high dew points indicating plenty of low level moisture. Going
forecast of just a chance of showers during the early morning
hours looks good as weak shortwave moves across the region...but
it appears more active convection will remain well south of the
On Friday the weak mid-level trough will exit east with any morning
showers/sprinkles ending by noon under gradually clearing skies east
to west. Synoptic background flow remains southwesterly with neutral
height falls indicative of little airmass change. Averaged model 925
mb thermal progs from 18-21Z are in the 19-22C range supporting late
afternoon highs mainly from 80 to 86F with perhaps a few upper 80s
in the Champlain and Connecticut River Valleys. Despite the warmth
dewpoints will be gradually lowering in the upper 50s to lower 60s
by late afternoon so humidity levels will feel tolerable.
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
-- Changed Discussion --As of 307 AM EDT Friday...Latest trends show system for Sunday
arriving several hours earlier associated with fast westerly flow
aloft. Otherwise...Saturday expect mostly sunny skies with
comfortable temperatures and humidity values. I anticipate
scattered fair weather cumulus clouds to develop over the terrain
as temperatures climb into the mid 70s to lower 80s depending upon
elevation. Light north/northwest winds will shift to the
south/southwest by Saturday Night. On Sunday...first ribbon of
enhanced 700 to 500mb moisture associated with weak mid level warm
air advection will shift from southwest to northeast across our
region. Expect maybe a few sprinkles...as moisture will have tough
time reaching the ground...given dry profiles. Deeper moisture and
better dynamics arrive after 18z...along with weak surface
boundary in the flow aloft. This energy/moisture will produce
additional scattered showers on Sunday afternoon/evening with
maybe a few rumbles of thunder. Overall...instability is limited
with CAPE values <500 J/kg and forcing is weak with energy getting
sheared out in the fast westerly flow aloft. I will continue to
mention chance pops with main focus over the mountains and after
18z Sunday. Progged 850mb temps warm to 16c ahead of
boundary...but clouds may keep values in the upper 70s to mid
80s...very similar to yesterday (Thursday).
-- End Changed Discussion --
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --As of 307 AM EDT Friday...Overall models are in good agreement
with large scale pattern across our region for next week. This
features a developing trof across the western and eastern conus
with high amplified ridge in the middle. Temperatures will be
above normal to start...but trend below normal by late next
week...with even the 0C 850mb isotherm progged to make an
appearance off both the latest 00z ECMWF/GFS. Some people are
excited about the arrival of cooler weather and are looking
forward to the upcoming winter months already.
For Sunday Night into Monday will continue to mention chance pops
with narrow ribbon of enhanced moisture and short wave energy
diving across our region with surface boundary. A rumble or two of
thunder is possible...especially northern NY around 00z.
Otherwise...qpf will once again be light and generally <0.25 with
this system. Surface high pres and weak cold air advection
develops for Monday into Tuesday with general dry conditions and
slightly above normal temps. The lack of a deep trof and limited
cold air advection behind boundary...supports only minor changes
in our thermal profiles for early next week.
Toward the end of next week a series of short waves and associated
cold front will help to carve out a deeper mid/upper level trof
across the ne conus. This support a gradually cooling trend in the
temps...with chances for scattered showers. The developing
northwest upslope flow supports the highest pops over the
mountains...especially Thursday into Friday. Progged temps start
near 15c for Tuesday...but cool to 10c by Thursday and single
digits by 12z Friday with brisk northwest winds. I will mention
temps in the 80s Tuesday...70s by Thursday...and 60s by next
Friday...with lows gradually cooling into the upper 30s to lower
50s depending upon elevation and vicinity to the warmer lake
-- End Changed Discussion --
.AVIATION /07Z Friday THROUGH Tuesday/...
Through 06Z Saturday...Look for VFR/MVFR conditions through about
15z this morning as plenty of low level moisture exists ahead of
an approaching cold front. This low level moisture will help to
create areas of fog to help reduce visibilities. In addition...
scattered showers ahead of the cold front will be moving across
the area which will also contribute to the MVFR conditions. The
front exits the area to the east around 15z and winds go from
south-southwest to west-northwest at speeds generally around 10
knots. Its at this point that drier air moves in and VFR
conditions quickly develop over the entire area for the remainder
of the period.
Outlook 06Z Saturday through Tuesday...
06Z Saturday through 00Z Monday...VFR/high pressure.
00Z Monday through 00Z Tuesday...VFR with scattered showers/MVFR
00Z Tuesday onward...VFR/high pressure.