Severe Thunderstorm Warning 159, NWS Albany, NY

Area Forecast Discussion
National Weather Service Albany NY
414 PM EDT Tue Sep 5 2017

.SYNOPSIS...
A cold front will slowly move across the region overnight,
bringing showers and thunderstorms, some of which may contain
locally heavy rain and gusty winds, especially areas south and
east of Albany. The front will stall just south and east of the
region as waves of low pressure track along the boundary
through Wednesday night, bringing occasional rain and cool
temperatures. Cool and somewhat unsettled conditions may linger
into Friday before high pressure builds into the region.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 415 PM EDT, isolated to scattered showers/thunderstorms
are finally firing up from the southeast Mohawk Valley south and
east into western New England and the mid Hudson Valley. A more
persistent band of showers/embedded thunderstorms continues
across the western Mohawk Valley into the southern Adirondacks.
This band is closer to the actual front, and also upper level
dynamics, including the right entrance region to an upper level
jet north of Lake Ontario.

Latest SPC mesoanalysis suggests an area of ML CAPES of
1000-1500 J/kg across portions of the mid Hudson Valley and NW
CT, with MU CAPES exceeding 1500 J/kg. This area or perhaps a
little farther N and W into the Berkshires and southern VT,
appears to have the greatest chance of stronger thunderstorms
through around 8 PM, with perhaps isolated strong/damaging wind
gusts and/or marginally severe hail. However, the bigger threat
remains heavy rainfall, including with the band across the
Mohawk Valley and Adirondacks, since the wind flow remains
nearly unidirectional through a deep layer, enhancing the
potential for training of cells. Will continue to watch closely
in case a short-fused flash flood watch needs to be issued.

The band of rain/thunderstorms to the N/W should continue slowly
expanding S/E through 8 PM, after briefly persisting across the
western Mohawk Valley. Areas within the Capital Region into the
Lake George region and southern VT should have increased
coverage of showers/storms through sunset, some with heavy rain.
Areas to the S/E of this region should continue t scattered
coverage of showers/storms, with a better chance of more
widespread activity and locally heavy rain occurring after
sunset through midnight.

Later tonight, still expect rounds of showers to move across the
region, with some embedded thunder possible, especially across
the mid Hudson Valley, NW CT and western MA. Locally heavy
downpours will be possible.

Temperatures will gradually fall as the front settles south and
east. Lows by daybreak should mainly be in the 50s.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Wednesday-Wednesday night, consensus of models suggest a
stronger wave of low pressure tracks northward along the frontal
boundary, which should stall across New England. Models also
suggest mid level boundary stalling in a N/S orientation across
the region, with some tightening of the H7-H5 thermal gradient.
So, expect lots of clouds, with periods of rain through this
time, with the best chance of steadiest rain appearing to be
Wednesday afternoon and night. Some locally heavy rain may occur
once again given nearby proximity of deep moisture and also
strengthening mid level forcing. Additional rainfall amts of
over one inch could occur, especially somewhere between the
Hudson River and western New England, including southern VT. It
will remain cool, with highs generally in the 50s and 60s, with
lows mainly in the 50s.

Thursday-Friday, the aforementioned low pressure wave should
slowly move northeast of the region Thursday morning, while the
main upper level trough slowly approaches from the Great Lakes
region. Steadier rain should end Thursday morning, with more
diurnally focused and Lake enhanced showers expected Thursday
afternoon into Friday. With such cool air aloft, can not rule
out some embedded low topped convection with small hail/graupel
with any taller showers. It will be breezy/cool, with highs
mainly in the 60s for valleys, 50s across higher terrain; and
lows ranging from the 40s across the higher terrain, to
lower/mid 50s elsewhere.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
After a low pressure trof from the Great Lakes to southern
Quebec retreats across the Canadian Maritimes Friday night, we
will be entering a period of tranquility all the while as
Hurricane Irma is expected to be wreaking havoc along the
southeast coast. Strong high pressure and subsidence developing
on the north side of the encroaching hurricane will result in
low humidities and seasonably cool conditions Saturday and
Sunday, with slightly warmer temperatures for the balance of the
period.

Will be keeping the entire period dry as it is not expected that
even if Irma tracks close enough to affect our weather, that it will
do so by mid-week. However, indications are that clouds will
probably be on the increase by Tuesday.  Otherwise, expect bright
and sunny conditions, especially Sunday and Monday.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
Band of scattered showers and isolated thunderstorms well north
and west will slowly build east while new showers and scattered
thunderstorms form over eastern NY. Have times VCSH at the TAF
sites from KGFL currently, through KALB and KPSF 19Z-20Z and
KPOU the latest around 22Z this afternoon. Have included tempo
groups late this afternoon and evening for MVFR conditions in
thunderstorms at all TAF sites since current radar and satellite
trends and mesoscale models show convection developing near the
TAF sites.

Once thunderstorms do develop, can amend for more precise
timing and see if there are potential IFR conditions to include
in the TAFs. Keeping VCSH in TAFs through tonight as activity
slowly diminishes and decreases in coverage. Ceilings should
remain MVFR through the night as shower activity deceases to
isolated coverage by daybreak. More showers could develop
through Wednesday morning and including VCSH at all TAF sites
Wednesday morning. Ceilings and visibilities should be
predominant just into VFR but could be borderline MVFR/VFR
ceilings.

Winds will be south to southwest at around 10 Kt this afternoon,
diminishing to 6 Kt or less from the west to north tonight, once
the initial band of showers and thunderstorms exits east. Winds
will be variable at 5 Kt or less Wednesday morning.

Outlook...

Wednesday Night: High Operational Impact. Likely SHRA.
Thursday: Moderate Operational Impact. Chance of SHRA.
Thursday Night:  Isolated SHRA.
Friday: Moderate Operational Impact. Scattered SHRA.
Friday Night: Low Operational Impact. Slight Chance of SHRA.
Saturday: Moderate Operational Impact. Chance of SHRA.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.

&&

.FIRE WEATHER...
Periods of rain, along with unseasonably cool temperatures, are
expected through Thursday.

&&

.HYDROLOGY...
The weather will be wet and unsettled today into Thursday.

Showers and thunderstorms will occur ahead of the cold front
through tonight. Some locally heavy downpours and ponding of
water on roadways and poor drainage flooding in low lying areas
is possible through around midnight. Rainfall amounts may range
greatly from a few tenths to over an inch. Isolated flash
flooding is possible in any training thunderstorms repeatedly
moving over an area. If the potential becomes more widespread,
then a short-fused flash flood watch may be needed.

Additional rainfall is likely Wednesday through Thursday with
several weak waves of low pressure moving along the cold front
stalled just east of the Hydro Service area. Additional rainfall
amounts of a half an inch to two inches are possible bringing
total rainfall amounts from today to Wednesday night in the 1 to
2.5 inch range for areas from Albany and points south and east,
with the higher amounts possible over western New England. Some
within bank rises are expected on the main stem rivers, but the
potential for widespread flooding is not anticipated at this
time. The latest MMEFS guidance, particularly the SREFs,
suggests that the Hoosic River in Williamstown, MA could
approach or surpass action stage, especially if 2 inches or
more of rainfall occurs, so trends will need to be watched.

For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

SYNOPSIS...KL/Wasula
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...ELH
AVIATION...NAS
FIRE WEATHER...KL/Wasula
HYDROLOGY...KL/Wasula

Hazardous Weather Outlook
National Weather Service Albany NY
440 PM EDT Tue Sep 5 2017

CTZ001-013-MAZ001-025-NYZ039>041-043-047>054-058>061-063>066-083-084-
VTZ013>015-061100-
Northern Litchfield-Southern Litchfield-Northern Berkshire-
Southern Berkshire-Southern Fulton-Montgomery-Northern Saratoga-
Northern Washington-Schoharie-Western Schenectady-
Eastern Schenectady-Southern Saratoga-Western Albany-Eastern Albany-
Western Rensselaer-Eastern Rensselaer-Western Greene-Eastern Greene-
Western Columbia-Eastern Columbia-Western Ulster-Eastern Ulster-
Western Dutchess-Eastern Dutchess-Southeast Warren-
Southern Washington-Bennington-Western Windham-Eastern Windham-
440 PM EDT Tue Sep 5 2017

This Hazardous Weather Outlook is for northwestern Connecticut,
western Massachusetts, the Schoharie Valley, eastern Catskills,
Greater Capital Region, the Lake George and Saratoga region,
including Washington County, the central and eastern Mohawk Valley,
the Taconics, and the mid Hudson Valley of east central New York,
and for southern Vermont.

.DAY ONE...Tonight.

There is a Slight Risk of severe thunderstorms ahead of a cold front
through this evening. The main severe threat will be damaging winds
of 58 mph or greater, but large hail one inch in diameter is also
possible.

The thunderstorms will be capable of producing very heavy rainfall
and locally heavy downpours which may produce ponding of water on
roadways, and poor drainage flooding in low lying and urban areas.
An isolated flash flood may occur if thunderstorms train or
repeatedly move over the same area.

If the potential for widespread flash flooding increases, then a
flash flood watch maybe needed later in time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Locally heavy rainfall will be possible Wednesday into Wednesday
night, especially for areas east of the Hudson River into western New
England, as waves of low pressure track along a nearly stationary
frontal boundary. An isolated flash flood may occur if bands of heavy
rain persist over the same area.

If the potential for widespread flash flooding increases, then a
flash flood watch maybe needed later in time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be requested early this evening.

NYZ032-033-038-042-082-061100-
Northern Herkimer-Hamilton-Southern Herkimer-Northern Warren-
Northern Fulton-
440 PM EDT Tue Sep 5 2017

This Hazardous Weather Outlook is for the southern Adirondacks of
east central New York.

.DAY ONE...Tonight.

There is a Marginal Risk that a few thunderstorms may become severe
ahead of a cold front into the early evening. The main severe threat
will be damaging winds of 58 mph or greater, but large hail one inch
in diameter is also possible.

The thunderstorms will be capable of producing very heavy rainfall
and locally heavy downpours which may produce ponding of water on
roadways, and poor drainage flooding in low lying and urban areas.
An isolated flash flood may occur if thunderstorms train or
repeatedly move over the same area.

If the potential for widespread flash flooding increases, then a
flash flood watch maybe needed later in time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
618 PM EDT TUE SEP 05 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0504 PM     TSTM WND DMG     2 SW EAST KENT          41.72N  73.43W
09/05/2017                   LITCHFIELD         CT   AMATEUR RADIO

            TREE AND WIRE DOWN.

&&

EVENT NUMBER ALY1704119

OKEEFE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
619 PM EDT TUE SEP 05 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0554 PM     TSTM WND DMG     WRIGHTVILLE             41.83N  73.14W
09/05/2017                   LITCHFIELD         CT   AMATEUR RADIO

            WIRES DOWN ON HORELE BOULEVARD

&&

EVENT NUMBER ALY1704120

IAA

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE ALBANY NY
622 PM EDT TUE SEP 05 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0518 PM     TSTM WND DMG     WRIGHTVILLE             41.83N  73.14W
09/05/2017                   LITCHFIELD         CT   AMATEUR RADIO

            WIRES DOWN ON HORELE BOULEVARD

&&

CORRECTED EVENT TIME

EVENT NUMBER ALY1704120

IAA

Special Weather Statement
National Weather Service Albany NY
627 PM EDT TUE SEP 5 2017

MAZ001-NYZ054-VTZ013>015-052330-
Northern Berkshire-Eastern Rensselaer-Eastern Windham-Western
Windham-Bennington-
627 PM EDT TUE SEP 5 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTH CENTRAL
BERKSHIRE...NORTHEASTERN RENSSELAER...BENNINGTON AND WINDHAM
COUNTIES...

At 626 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Dorset to near Berlin. Movement was
northeast at 45 mph.

Winds in excess of 40 mph and pea size hail are possible with these
storms.

These storms will be near...
  Manchester Center around 630 PM EDT.
  Londonderry around 635 PM EDT.
  Williamstown around 640 PM EDT.
  Hoosick Falls and Pownal around 645 PM EDT.
  Bennington around 655 PM EDT.
  Stratton around 715 PM EDT.
  West Wardsboro around 720 PM EDT.
  Townshend around 730 PM EDT.

Other locations impacted by these storms include Goose City,
Chiselville, Readsboro Falls, Grafton, South Shaftsbury, South
Windham, Hoosick, Hidden Valley, Bromley Village and Cambridgeport.

Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 4314 7244 4274 7266 4274 7302 4272 7302
      4270 7352 4274 7351 4294 7334 4294 7328
      4302 7327 4331 7303 4330 7299 4329 7299
      4330 7297 4330 7282 4325 7282 4322 7269
      4323 7243
TIME...MOT...LOC 2226Z 232DEG 38KT 4327 7299 4269 7345

NAS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
718 PM EDT TUE SEP 05 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0522 PM     TSTM WND DMG     1 SSW BRATTLEBORO       42.85N  72.58W
09/05/2017                   WINDHAM            VT   FACEBOOK

            TREE DOWN.

&&

EVENT NUMBER ALY1704121

OKEEFE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
720 PM EDT TUE SEP 05 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0525 PM     TSTM WND DMG     1 NE BRATTLEBORO        42.87N  72.56W
09/05/2017                   WINDHAM            VT   FACEBOOK

            TREES DOWN.

&&

EVENT NUMBER ALY1704122

OKEEFE