FXUS61 KBTV 201849
AREA FORECAST DISCUSSION
National Weather Service Burlington VT
249 PM EDT Thu Jun 20 2019
Heavy rainfall continues to be the main concern this afternoon
and evening as a line of showers with embedded thunderstorms
tracks through the region this afternoon. The first line will
eventually pivot to the northeast and a secondary line of
showers will bring more rainfall to the region. Localized flash
flooding will be possible through the evening hours generally
across central and southern Vermont. Cooler and drier weather
is expected for Friday and Saturday. A warming trend begins on
Sunday and continues into early next week. Dry weather will
continue on Sunday...then the chances for showers and some
thunderstorms will increase early next week.
.NEAR TERM /THROUGH FRIDAY NIGHT/...
As of 152 PM EDT Thursday...A Flash Flood Watch is in effect
this afternoon and evening as several rounds of heavy rainfall
with embedded thunderstorms track across the North Country. The
first line of showers has been producing upwards of 1 to 2
inches an hour and we`ve already gotten reports across Essex
county NY into Addison VT of flooding. With high pwats and
strong 925-850mb moisture transport right into southern Vermont
anticipate flash flooding to remain a threat well into the
The Flash Flood Watch will continue to be in effect through 11pm
as headwaters guidance across the region is between 2 to 3
inches over 3 hours and flash flood guidance is between 1.8 to
2.2 inches over 3 hours. With the rainfall already on the ground
and a second line of showers expected to track through the North
County early this evening, we could exceed those 3 hour FFG
Based on the latest CAM output the mesolow should shortly start
to track towards the east and will push another round of
strongly force highly efficient rain showers through the North
Country. Some weak cape across southern Vermont will lead to at
least some convective elements in the rain showers. So we`ll
need to monitor any areas where heavy rainfall ends up training
over the rainfall from this afternoon.
Heading into this evening, the back edge of the system is
already visible on MRMS radar and the IR satellite. So shortly
between 00-03z anticipate most of the rain showers to exit
Vermont. The instability falls off rapidly and the frontal
boundary should track towards the east and out of the North
Country by 03z at the latest.
Overnight we`ll see widespread low cloud cover and some patchy
fog developing in protected river valleys. Given we should see
light northwest flow of 5-9 kts, I dont think we`ll see
widespread coverage but should the winds weaken to less than
3kts then fog and significantly reduced visibilities is likely.
With showers exiting the region this evening anticipate much of
tomorrow being a pleasant day. We should see heights rising
through the day and even with the cold air advection aloft temps
should warm into the upper 60s to low 70s. Friday night should
be a quiet evening with temps falling into the low 50s to upper
40s in the typical cold spots.
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 245 PM EDT Thursday...A decent shortwave will descend
across the North Country along the western periphery of the
upper level trough late Saturday morning into Saturday
afternoon. Models are showing a pocket of colder temperatures at
the 850mb and 700 mb levels associated with this feature as it
tracks across northwestern Vermont. The cooler temps aloft
should help steepen the mid-level lapse rates in somewhat
increase instability across the Northeast Kingdom come Saturday
afternoon. This should help spark scattered showers and possibly
a thunderstorm or two Saturday afternoon across northeastern
Vermont but it looks like much of the North Country will remain
on the dry side. While the shortwave skirts across Vermont,
height rises aloft associated with deep layer ridging will help
stabilize the atmosphere, leading to increasingly sunny
conditions Saturday afternoon and evening. Temperatures on
Saturday will be right around seasonal normals with highs in the
low to upper 70s.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 245 PM EDT Thursday...Sunday will be a beautiful day
across the North Country with deep layer ridging helping to
bring sunny and dry conditions to the region. Temperatures will
be noticeable warmer than those observed on Saturday as highs
climb into the upper 70s to the lower to mid 80s. This period of
drier and warmer weather will persist through Monday with a
high amplitude upper level ridge remaining entrenched across the
region. Previous model runs had shown this ridge beginning to
flatten out with showers developing during the afternoon hours
across northern New York. However, the latest guidance now
suggests that the upper level ridge will remain quite a bit
stronger than initially thought. Temperatures on Monday now
appear to be the warmest of the week with highs climbing into
the low to mid 80s across the entire region.
Unsettled weather returns Tuesday into Wednesday although there
is some uncertainty to when the upper level ridge begins to
break down. Whether the ridge breaks down Tuesday, Wednesday or
Thursday, a period of showers and thunderstorms, some of which
may be strong, will move through the region. Until then,
temperatures will remain above normal through the period.
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Through 18Z Friday...Expect widely varying conditions this
afternoon as widespread rain showers with some embedded
thunderstorms mainly just impacting RUT. As a low pressure
system pushed a frontal boundary through the region this evening
anticipate winds becoming northwest and ceilings to rapidly
lower to low MVFR with IFR 700-900 foot ceilings. The low
ceilings should continue throughout the overnight hours before
gradually improving by day break Friday morning. Visibilities
across the region will be as low as 1 1/2SM in heavy rain and
will improve between 00-03z returning to VFR. Winds will
generally be under 10 knots through the period...with a
noticeable wind shift to the northwest behind the frontal
boundary after 06z.
Friday Night: VFR. Slight chance SHRA.
Saturday: VFR. Slight chance SHRA.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. Chance SHRA.
Monday Night: VFR. Chance SHRA.
Tuesday: VFR. Chance SHRA.
As of 1206 PM EDT Thursday...A Flash Flood Watch is in Effect
through 11 PM this evening. Still looking at a general
widespread one to three inch rain event. Axis of highest amounts
was initially over southern Vermont...but as low pressure and
surface boundary set up across portions of the northern
Adirondacks in New York and extended into Vermont from Addison
County northeast up into Essex County Vermont. Heavier rain may
be concentrated across this area this afternoon and evening
before boundary shifts east. Southern areas will have the best
potential to see some thunderstorms and this could enhance
rainfall totals across this area as well. Overall mainstem
rivers are not expected to reach flood stage...but the East
Branch of the Ausable and Otter Creek might be two to watch.
Otherwise impacts related to the one to two inch rainfall
include sharp rises on smaller rivers and streams which could
lead to localized flash flooding...minor field flooding... and
ponding of water on roadways.
VT...Flash Flood Watch until 11 PM EDT this evening for VTZ001>012-
NY...Flash Flood Watch until 11 PM EDT this evening for NYZ026>031-