Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Burlington Vermont
1258 am EDT sun Jul 5 2015
an upper trough will move through the region tonight with a chance
of showers and a slight chance of thunderstorms. A ridge of high
pressure at the surface and aloft will build into the north
country Sunday and Monday...with fair and dry weather expected. The
next chance for showers and thunderstorms across the north country
will be Tuesday and Wednesday.
Near term /until 6 am this morning/...
as of 1255 am EDT Sunday...updated pop forecast to match current radar
trends. Also, increased the areal coverage of fog overnight and
bumped temperatures up several degrees. Current radar shows band of rain
showers with embedded rumbles of thunder slowly weakening over
Rutland/Windsor counties this morning with additional showers
upstream over the Ottawa Valley. These showers will impact
northern New York/Vermont through early this morning...before dissipating.
Otherwise...patchy fog has already developed in the deeper
protected valleys and will continue...with temperatures in the 50s to
Area of showers and thunderstorms which developed over the
Adirondacks this afternoon moved into Champlain Valley and
northern Vermont early this evening...and is now diminishing in
both coverage and intensity as it gradually depresses
southeastward across central Vermont and Essex County New York.
Fairly impressive rainfall amounts in some areas according to
radar estimates...with 1 to 2 inches in some areas...especially in
parts of Essex and Clinton counties in New York. Coverage of
showers will continue to decrease overnight as area of showers
settles into south central Vermont. But the threat for a few more
popup showers will continue over next several hours areawide as
upper trough gradually makes its way east across region. Have made
some adjustments to probability of precipitation to reflect latest conditions and trends.
With todays rainfall and expectation of light winds and some
clearing later tonight...expect some patchy fog to
form...especially in the more climatology favored mountain and river
valleys. Temperature forecast remains on track with lows expected to be
mainly in the 50s.
Short term /6 am this morning through Monday night/...
as of 351 PM EDT Saturday...models showing a ridge of high
pressure at the surface and aloft will build into the region
Sunday and Monday...with 500 mb heights building through the
period. Expecting temperatures to climb into the lower 80s on
Sunday and then into the middle and upper 80s on Monday. Mainly
partly to mostly sunny Sunday and Monday with fair and dry weather
expected through the period.
Long term /Tuesday through Saturday/...
as of 322 PM EDT Saturday...extended portion of the forecast
begins on Tuesday where medium range guidance continues to differ
in the timing of a frontal boundary passing through Tuesday night
into Wednesday associated with low pressure moving over the
southern tip of James Bay. Models are in decent agreement for
Tuesday with the County Warning Area in the warm sector and some modest
instability leading to the chance for some popup tsra, but the
timing of the following cold front differs. 12z runs of the European model (ecmwf)
and Canadian Gem are in good agreement offering a later frontal
passage during middle-day Wednesday while the GFS continues to to
show a faster arrival time Tuesday night. The timing of the front
would make a significant difference in the convective
probabilities, so have continued to forecast a blend with showers
and a slight chance of thunderstorms Tuesday night, then a little
more convection and higher probability of precipitation for Wednesday. Beyond Wednesday,
guidance is in really good agreement with the pattern turning
quiet for the end of the week. Fairly zonal flow sets up aloft
with very little shortwave energy moving through. Surface high
pressure settles over the area so we should see a dry end to the
week with temperatures right around seasonal values, highs in the
upper 70s to low 80s, and lows in the middle 50s to lower 60s.
Aviation /06z Sunday through Thursday/...
through 00z Monday...mainly VFR conditions are expected through
the period with the exception of some MVFR in lingering showers
this evening and period of localized IFR/LIFR in fog/br
overnight. Line of rain showers and embedded thunderstorms
weakening as it moves eastward this evening...but will still bring
a period of rain to mpv...which will reduce visibilities to MVFR
(and perhaps briefly ifr). Otherwise...no additional impacts
expected at other taf sites. Cloud deck scatters out
overnight...and radiational cooling combined with lingering low
level moisture due to todays rainfall will lead to the development
of fog/br overnight and into early Sunday morning. Coverage not
expected to be widespread with some wind remaining in the boundary
layer...but IFR/LIFR still likely at least for a time at mpv/slk.
Some brief MVFR also possible at pbg. No fog/br forecast at
btv/rut/mss. Any fog/br lifts and scatters out after 12z with only
scattered fair weather cumulus expected for later Sunday. Winds
light and variable tonight (except southeast 4-5kt at rut) turn westerly
on Sunday...but remaining less than 10 knots.
Outlook 00z Monday through Thursday...
00z Monday - 12z Tue: VFR. IFR fog possible at kmpv/kslk 08-12z Monday.
12z Tuesday - 00z Thu: VFR west/scattered MVFR thunderstorms and rain possible.
00z Thursday - 00z Fri: VFR. Early morning IFR fog possible at
ktyx radar will be out of service until Tuesday or later.
equipment...weather forecast office btv