630 updated BTV discussion
https://forecast.weather.gov/product.php?site=BTV&issuedby=BTV&product=AFD&format=CI&version=1&glossary=1
As of 632 PM EST Sunday...Radar showing freezing rain expanding
quickly toward our cwa this evening with precip expected to
develop in the next 1 to 2 hours. Water vapor shows impressive
rapidly developing cyclone over the central Plains, with potent
s/w energy/dynamics helping to enhance thunderstorm development
in the Ohio Valley. In addition, strong-deep layer moisture and
thermal advection continues from the northern Ohio Valley into
central NY, as precip continues to expand in areal coverage.
Upstream 3 to 4 hour qpf amounts at BUF are impressive with
>0.75" occurring, its this heavy axis of precip with elevated
instability that will move acrs our cwa later tonight into
Monday morning. I have bumped up qpf amounts to match upstream
trends and latest CAM output. Given crnt temps in the upper
teens to mid 20s, most precip starts as freezing rain, but a
switch occurs first along portions of the northern Dacks and
central/southern CPV, associated with downslope warming.
Elsewhere, cold air and freezing rain lingers the longest over
the SLV and east of the Greens, including the CT River Valley.
Still thinking ice accumulations of 0.15" to 0.30" in the
advisory and 0.50" to 0.75" in the ice storm warning looks
reasonable, given latest 21z HRRR and RAP data. Just minor
tweaks made in grids attm.
The gusty west to southwest winds on backside, especially parts
of the SLV and downslope portions of the eastern Greens could
produce additional power outages on Monday night into Tuesday.
Travel will be extremely difficult late this evening and
especially during the Monday morning commute.