438
FXUS61 KBTV 161352
AFDBTV

AREA FORECAST DISCUSSION
National Weather Service Burlington VT
952 AM EDT Sat Mar 16 2019

.SYNOPSIS...
After the mild temperatures observed the last few days, a
cooling trend can be expected through the weekend. There will be
some lingering snow showers during the day today, but these will
diminish by Sunday, giving way to a dry but cold end to the
weekend. The start of next week will feature continued below-
normal temperatures, with mainly dry weather. Temperatures start
to rise mid-week, along with increasing precipitation chances.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 952 AM EDT Saturday...Forecast remains on track as of
late morning. As a result, no changes or adjustments were
needed. Have a great day.

Prior discussion...
A Flood Watch remains in effect for most of the forecast area
through this evening after temperatures rose into the 50s
Thursday and Friday. These mild temperatures have led to rapid
loss of snowmelt, particularly in valley locations, which has
subsequently led to rises in river levels throughout the region.
River gauges reported rises generally between 1 and 3 feet
through the day Friday, before generally cresting overnight. So
far, while this has led to a few rivers rising into action
stage, there has been no reported impacts from flooding.
However, given the ice thicknesses of generally a foot or a foot
and a half, there remains the potential for is isolated ice
jam. Thus have kept the flood watch in effect. See hydro
discussion for more details.

An upper-level shortwave moving through the region overnight has
provided some brief enhanced ascent to support some scattered
snow showers. These showers have mainly been over northern New
York and over higher terrain of the Green Mountains in Vermont.
The lower atmosphere will remain fairly unstable through the day
today in response to continuing cold air advection, so expect
scattered light snow showers to continue through the day. A lack
of deep moisture will limit overall snow amounts, but higher
peaks of the northern Green Mountains and the northwestern
slopes of the northern Adirondacks will pick up between 1 and 4
inches through Sunday morning. Lower elevations including the
Saint Lawrence Valley and Champlain Valley, along with southern
and eastern Vermont, will only see a dusting up to an inch.

A well-mixed PBL extending to between 800 and 850mb throughout
the day today will allow for the continuation of some gusty
westerly winds. The strongest gusts, between 15 and 25 mph, will
be observed in the morning hours today, then diminish some
going into the afternoon as the low-level jet weakens and
departs to the east. Highs today will be in the 30s.

Temperatures tonight will be noticeably colder than the previous
few nights, returning to the teens/low 20s by dawn Sunday
morning. Subtle height rises and negative moisture advection
during the day Sunday will keep conditions drier than Saturday.
However, temperatures Sunday will return to below normal, with
highs expected to be in the upper 20s to low 30s. Some brisk
west winds can be expected , especially during the afternoon
hours, which will keep wind chills in the teens to low 20s.

&&

.SHORT TERM /SUNDAY NIGHT/...
As of 414 AM EDT Saturday...A upper level short wave trof providing
some weak lift will move through the region from the northwest
Sunday night. There is little moisture to work with but weak some
cold advection and upslope flow may squeeze out some flurries or
light snow showers with little accumulation mainly in the mountains.
Lows by Monday morning will range from the upper single digits in
the cold spots to the teens in the valleys.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 414 AM EDT Saturday...The long term is dominated by a mean
upper-level long wave trof in eastern north America with periodic
short wave trofs and ridges moving through it.

The weak surface and upper level short wave trof will move out on
Monday but there may be a lingering flurry or snow shower on Monday
with cold advection and partly sunny skies.

High pressure will move over the eastern CONUS Tue-Wed bringing cold
and dry weather and mostly clear to partly cloudy skies.

The next weather system comes Thu-Fri as the upper level trof
sharpens and deepens over the Northeast ahead of which will be a
slight warm up on Thursday with a chance of snow and showers and a
bit breezy conditions. EC/GFS in agreement that a cold front will
follow with any rain showers changing to snow showers with some
pretty chilly air expected on brisk northerly winds by Friday.
Temperatures start the period on the seasonably cool side with highs
in the upper 20s to lower 30s Monday and Tuesday, then moderate Wed-
Thu when highs top out from from the upper 30s to mid 40s but
cooling during Friday.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
Through 12Z Sunday...Spotty snow showers continue across the
region, resulting in some temporary IFR visibilities at the New
York TAF sites. HiRes models indicate a line of convective snow
forming right along a frontal boundary to our north as the
boundary pushes southward into our forecast area over the next
few hours. This could result in a brief period of locally
moderate snow, but at this point not confident enough on exact
timing and placement of the line to indicate anything more than
VCSH at most of the TAF sites. Scattered snow showers will
continue across the forecast area through the day, then diminish
overnight. Despite the showers however, expecting most sites to
remain primarily VFR with only temporary visibility and ceiling
reductions. The exception to this will be KSLK, which will see
steadier snow through the day. Gusty westerly winds can be
expected through the TAF period. Gusts this morning through this
afternoon will be in the 15-30 kt range, while gusts this
evening into tonight will be 10-20 kts.

Outlook...

Sunday: VFR. NO SIG WX.
Sunday Night: VFR. Slight chance SHSN.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.

&&

.HYDROLOGY...
A Flood Watch remains in effect until 8 pm today for the entire
forecast area except Grand Isle County VT. Temperatures rising
well into the 50s over the last couple of days has led to rapid
snowmelt and subsequent river rises between 1 and 3 feet. While
rivers have generally crested overnight, temperatures will
remain above freezing for much of the area through this
afternoon. Thus, while the greatest threat is over, additional
rises on river are still possible. This leads to a continued
threat for isolated ice jams today. So far, only one ice jam has
been reported, which was along the Mad River at Moretown. This
caused the river to very briefly crest to minor flood stage
around midnight this morning, but since then the river has been
receding. We will continue to monitor this and other area
rivers for ice jams.

Remember that river levels can change suddenly during the
breakup of river ice. Any observed flooding affecting roadways
should be reported to local law enforcement.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Flood Watch until 8 PM EDT this evening for VTZ002>012-016>019.
NY...Flood Watch until 8 PM EDT this evening for NYZ026>031-034-035-
     087.

&&

$$
SYNOPSIS...RSD
NEAR TERM...JMG/RSD
SHORT TERM...Sisson
LONG TERM...Sisson
AVIATION...RSD
HYDROLOGY...WFO BTV