National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 181753
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
153 PM EDT Fri May 18 2018

.SYNOPSIS...
One last dry day today before this weekend brings rain and cooler
temperatures in as low pressure lifts northeastward from the Ohio
Valley into New York and New England. Next week will see a return to
drier conditions and above normal temperatures.

&&

.NEAR TERM /THROUGH SATURDAY/...
-- Changed Discussion --
As of 144 PM EDT Friday...Clear skies and generally northerly
flow will continue through the rest of the day. Current forecast
is in good shape with no changes needed.

Previous discussion...Dry weather hangs around for one more day
as a high pressure ridge remains before breaking down later
this evening. While skies will remain relatively cloud free,
especially across the northern counties, northerly flow will
continue for most of the day and keep high temps again right
near seasonal normals. The weakens overnight and moisture along
the Southeastern US and the Mid-Atlantic will be allowed to make
its way north. A weak shortwave moves through quickly as the
ridge breaks down and will rapidly eject northeastward. As seen
with previous model runs, ample moisture is in place and PWATs
up to 1.5 inches which will lead to widespread rain. Instability
remains relatively weak and the quick moving nature of this
system will keep rainfall amounts from getting too high with
amounts generally around 0.5 inch or less for the day Saturday.
A low level jet moves into the area by midday with 850mb winds
of 35 - 55 knots centered over the Dacks. Afternoon gusts of
15-25 knots are possible as the system passes through with some
isolated higher gusts in the mountain areas. That all being
said, a chance of a rumble of thunder Saturday afternoon can`t
be ruled out.
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 417 AM EDT Friday...Rain will become more showery in
nature Saturday night as the best warm advection and overrunning
lifts northeast of the area by the evening hours. Some of the
area especially in northern NY may get into the warm sector
while east of the Greens its less likely. While showers are
still likely Saturday night there could be a period during the
night without much going on before a cold front approaches the
St. Lawrence Valley by early Sunday with an increase in precip
probabilities. The NAM is still showing some CAPE to around 250
J/kg, mainly elevated, while the GFS is less. The Showalter
index is near zero and Ks in the 30s, so a rumble of thunder is
not out of the question, but averaging NAM/GFS keeps most of the
thunder out of the forecast this point. Simulated satellite
from the BTV WRF does show some embedded convective cells might
be possible as well. The NAM/GFS have the cold front on our
doorstep by 12z Sun through ECMWF is a bit slower. The cold
front will have showers ahead and along the front but clearing
behind. The front will move steadily southeast Sunday with a
decreasing probability of precipitation from northwest to
southeast but should clear most of our area by mid afternoon.
Timing will play a role in the instability ahead of the front
and indications are that some weak instability will develop
south and east of BTV mainly south central VT (VSF) and points
south. Again a blend of NAM/GFS keeps MUCAPE below 250 J/kg so
not including thunder at this time. Looking like about a half
inch of rain is expected with locally 0.75 to near an inch over
the south central Greens. Clearing skies are expected Sunday
afternoon with mainly clear skies Sunday night. Temperatures
Saturday night will be steady or rising ranging from early
evening lows the upper 40s east of the Greens to mid to upper
50s in the St. Lawrence valley rising through the 50s by Sunday
morning.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 417 AM EDT Friday...Monday is looking with a NW flow
aloft and weak high pressure. Things become a bit more uncertain
by Tue-Wed next week as the flow aloft backs to more westerly
and we are more under the influence of the southern branch of
the split confluent flow over the eastern CONUS. As a result a
bit more moisture advects back into the region with perhaps a
weak short wave or two embedded for another chance of showers
Tuesday into Wednesday with the higher chances on Wed. It does
look the like the models want to bring a more significant wave
and cold front southeast from the northern branch with showers
perhaps a thunderstorm Wed with clearing and drier weather by
Thursday. Temperatures continuing slightly above to near average
with highs in the upper 60s to lower 70s and lows in the 40s to
around 50 each day.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Through 18Z Saturday...Generally VFR through the overnight
hours before lowered ceilings and rain starts to move into the
region. Winds will be largely orographically forced through the
afternoon as channeled flow continues through both the Saint
Lawrence and Champlain valleys with light and variable
elsewhere. Winds become light overnight but will rapidly pick
up out of the south southeast in the morning hours Saturday as
mid clouds move in with a ceiling around 6000-7000 feet by 12z.
Rain showers will spread from the southwest to the northeast
with rain expected at SLK and RUT by 14-16z Saturday. Within any
of the showers there`s potential for some MVFR visibilities.

Outlook...

Saturday Night: Mainly VFR, with local IFR possible. Likely SHRA,
Slight chance TSRA.
Sunday: Mainly VFR, with areas MVFR possible. Chance SHRA.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Chance SHRA.
Tuesday Night: VFR. Chance SHRA.
Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA.
-- End Changed Discussion --

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Verasamy
NEAR TERM...Deal/Verasamy
SHORT TERM...Sisson
LONG TERM...Sisson
AVIATION...Deal