FXUS61 KBTV 091130
Area Forecast Discussion
National Weather Service Burlington VT
730 AM EDT Sun May 9 2021
A mix of sun and clouds will give away to mostly cloudy skies
this afternoon with scattered light rain showers possible.
Additional light rain is likely across southern Vermont
overnight this evening, before additional terrain driven showers
develop on Monday afternoon. Temperatures will continue to be
below normal for daytime highs with values in the upper 50s to
mid 60s, while lows will be in the 40s. A cool and unsettled
pattern continues into Tuesday of this upcoming week.
.NEAR TERM /THROUGH MONDAY/...
As of 725 AM EDT Sunday...Updated fcst to mention more sunshine
acrs our fa, especially parts of the cpv, where early morning
vis shows some clearing. Otherwise, pockets of low clouds
continue acrs the slv and western dacks, which should dissipate
by 14z, before additional high clouds overspread the entire fa
this aftn. With more sunshine this morning, did bump temps up a
degree or two with upper 50s to mid 60s likely.
Water vapor indicating we remain in cyclonic nw flow aloft with
pocket of mid/upper lvl subsidence overhead, while llvl
moisture is trapped acrs northern NY. These low clouds should
dissipate by 15z, but expecting additional mid/upper lvl clouds
to race eastward ahead of next system located over the midwest.
Latest guidance is consistent is showing best moisture/dynamics
sliding to our south in fast westerly flow aloft. Progressive
nature of system, no closed 5h/7h circulations and pws <0.50" wl
result in just light rain, mainly acrs Rutland/Windsor Counties
toward 00z this evening. Have continued with the idea of likely
pops for our southern VT counties with chc pops further north
and schc near the international border. Qpf is a couple
hundreths acrs central VT and up to 0.15 near VSF. Have noted
HRRR/NAM 3KM and RAP have weak instability developing on
northern extend of clouds shield acrs northern dacks with some
composite reflectivity returns, mainly driven by trrn this aftn.
Have mention some schc/low chc pops to cover this potential for
a pop up shower, given instability and steep sfc to 3 km >7.5
C/km. Forcing and overall deep layer moisture is limited, so
this wl result in minimal areal coverage. Progged 925mb temps
warm a degree or two from yesterday, with values in the 6-7C
range, supporting upper 50s to mid 60s most locations. Tonight,
clouds and light rain wl keep temps mainly in the 40s to near
50f most locations with highest pops acrs Rutland/Windsor
Counties. On Monday, any lingering moisture quickly exits our
fa, associated with westerly 5h jet of 50 to 70 knots.
Meanwhile, potent northern stream 5h vort wl approach western
cwa by 18z, combined with developing instability from cool pool
aloft, expect pop up showers to develop. High pops wl be acrs
the northern dacks into the Green Mtns of central/northern VT
btwn 16z-22z Monday. The lack of deep layer moisture and limited
instability with cape values in the 200 to 400 j/kg, wl
minimize convective updrafts and overall coverage of showers.
Have chc pops with qpf up to 0.10 in the heaviest activity.
Temps are once again in the mid 50s to lower 60s.
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 340 AM EDT Sunday...Convective rain showers will wane Monday
night as daytime heating is lost and relatively drier air advects in
from the west. However, the upper low will pass overhead the North
Country on Tuesday bringing a return of rain showers, especially in
the afternoon. At the same, cold air advection will continue under
west/northwest flow, keeping temperatures cool. Early morning lows
on Tuesday will be in the mid 30s to low 40s and daytime highs only
in the mid 40s to mid 50s. Winds will be fairly breezy with
sustained wind speeds of 10 to 15 mph and gusts up to 20 mph. Rain
showers will likely linger overnight into Wednesday morning,
becoming terrain driven and transitioning to snow at or above 2000
ft AGL. Overall, rainfall will be light with totals less than one
quarter of an inch. Temperatures will be chilly overnight Tuesday
into Wednesday, and frost is possible across the Adirondacks and
east of the Green Mountains where low temperatures will be near
freezing. Within the Saint Lawrence and Champlain Valleys low
temperatures are expected in the upper 30s to low 40s.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 340 AM EDT Sunday...A gradual warming trend will begin on
Wednesday as the upper low finally departs eastward, but not before
swinging one last shortwave through the area late Wednesday. This
will result in a chance of light rain Wednesday afternoon/evening,
especially across the Northeast Kingdom of Vermont. High
temperatures on Wednesday will be in the 50s to low 60s. Dry weather
is then expected thereafter as ridging builds in from the west. At
this time, Thursday looks to be the pick of the week with sunny
skies and highs in the mid to upper 60s. As we head into the end of
the week, model guidance offers a wide variety of solutions.
Therefore, have kept with the previous forecast of chance of rain
and partly cloudy skies each day. Temperatures look to remain near
normal during this time with highs in the 60s and overnight lows in
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Through 12Z Monday...Early morning vis and obs show pockets of
low stratus clouds acrs the slv/western dacks with ifr cigs.
Based on satl trends and sounding data, expect these ifr
conditions to trend to mvfr by 13z and vfr by 14z this morning,
with vfr prevailing at all other sites. Additional mid/upper lvl
clouds overspread the entire fa this aftn with cigs trending
toward mvfr at rut/slk tonight. A period of ifr is possible at
slk aft 06z. Winds are under 6 knots from the west/northwest
this morning, becoming trrn driven by evening.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night: VFR. Slight chance SHRA.
Tuesday: Mainly VFR, with local MVFR possible. Chance SHRA.
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.