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Area forecast discussion 
National Weather Service Buffalo New York
648 am EST Friday Feb 27 2015

Synopsis...
with the exception of some Minor Lake effect snow along the
immediate Lake Ontario shoreline today...western New York should see
uneventful but continued cold weather today and Saturday as high
pressure slowly moves through the Ohio Valley. The next system will
arrive Sunday...with widespread snow moving into the region.

&&

Near term /through tonight/...
expect very light mesoscale lake effect snow along the South Shore
of Lake Ontario. Skies are will clear this morning as high
pressure ridges north of the region settles southward through the
day. This will redirect any lingering lake effect snow from the
South Shore of the lake to the Eastern Shore of the lake. Subsidence
within the ridge will suppress the lake effect development and keeps
it to scattered light snow showers with minor accumulations. Skies
will be sunny across the majority of the forecast area later this
afternoon as the shallow layer of moisture mixes out. High temperatures
today will be limited to the middle single numbers to the middle
teens...despite the sunshine.

High pressure ridged across the region tonight will bring about
clear skies and light winds...perfect conditions for radiational
cooling. Expect overnight lows in the lower single numbers along the
Lake Ontario shore to the negative single numbers inland and near
minus 10 over the southern tier.

&&

Short term /Saturday through Monday night/...
the bitter cold of recent weeks will relax during this period...as a
split flow over the lower 48 will result in our region being
dominated by Pacific airmasses. The warming trend will come at the
expense of receiving more accumulating snow though...as with higher
temperatures and a southerly component to the jet typically comes
the potential for greater precipitation amounts.

Saturday will undoubtedly prove to be the nicer of the two weekend
days as expansive high pressure centered over Pennsylvania will
supply the bulk of our region with fair weather. The exception will
be found east of Lake Ontario where some nuisance lake driven snow
showers will persist. A solid cap under 5k feet...a moderately sheared
boundary layer and plenty of ice on the eastern end of Lake Ontario
will all work against anything organized and keep accumulations
under an inch (centered on tug hill). This will be the last real
cold day in awhile as maximum temperatures will be within a few degrees of 20.

The surface high will drift off the New Jersey coast late Saturday night
and Sunday...while Pacific based moisture will streak eastward from
the Central Plains to the lower Great Lakes. This moisture will be
pushed up and over the relatively cold dome of air over our region
by a 40kt low level jet...which will be found ahead of a wavy
frontal boundary approaching from the upper Great Lakes. The
deepening lift supplied by a 140kt h25 jet and warm advection in the
boundary layer will lead to widespread light snow across the region
by the afternoon. Snow accumulations for this first day of March
will generally range from an inch in most areas to as much as 3
inches across parts of the southern tier. Will continue the trend of
raising probability of precipitation...going with near 90 in the west and 80 east of Lake
Ontario. These values are generally 20 points higher than the
mainstream MOS guidance packages.

The widespread accumulating snow will continue through most of
Sunday night as the wavy frontal boundary will gradually push across
the forecast area. While the strongest frontogenetic forcing will
stay to our south in the vicinity of the 50kt low level jet...a
vigorous 500 mb shortwave plowing across the lower Great Lakes will
combine with convergence ahead and along the frontal boundary to
produce another 2/3 inches of snow. The 24 hour forecast snowfall
amounts from Sunday through Sunday night would be enough to warrant
at least an advisory. Will continue to address this potential in the
hazardous weather outlook (hwo) product. Given the high confidence
of this scenario...have boosted Sunday night probability of precipitation to 100.

On Monday...the strong shortwave will round the base of the
supporting 500 mb trough and exit across New England while a large area
of high pressure will build across the upper Great Lakes. Much drier
air associated with the approaching surface high will combine with the
subsidence to end the morning snow showers while partially clearing
skies across the region. The only snow showers expected by afternoon
will be driven by a weak lake response southeast of Lake Ontario.

&&

Long term /Tuesday through Thursday/...
our next storm system will come Tuesday into Wednesday as a strong
500mb shortwave and attendant vorticity maximum will eject eastward out of a
broad West Coast trough. Deep southerly flow ahead of this deepening
Great Lakes cutter type low will spread a plume of warm moist air
northward across the Ohio Valley and northeast. This will be the
first storm in more than a month that could bring p-type issues back
to the forecast midweek. Both GFS and European model (ecmwf) 850mb temperatures surge
to near +8c by Tuesday night so while precipitation should begin as
some snow Tuesday eventually warmer air aloft will likely bring a
wintry mix and possible even change over to plain rain Tuesday night
into Wednesday as warmer air aloft mixes down to the surface. Timing
differences in models remain but both show a deepening low cutting
just to our west which is a favorable pattern for gusty winds across
our forecast area. This system will need to be closely watched in
the coming days with the wintry mix and potential gusty winds. Cold
air wrapping around the back of the system should bring a return to
snowfall and sub-freezing temperatures on Thursday.

&&

Aviation /12z Friday through Tuesday/...
light lake effect along the South Shore of Lake Ontario will produce
MVFR ceilings and visibilities and skies will clear across the rest of the
region where VFR will prevail through the taf period.



Outlook...
Friday night...mainly VFR.
Saturday...VFR with a chance of MVFR/IFR in lake effect snow
showers southeast of Lake Ontario.
Sunday...MVFR/IFR with snow likely.
Monday...MVFR with snow showers...then improving to VFR.
Tuesday...lowering clouds to MVFR/IFR with a wintry mix.

&&

Marine...
high pressure slowly moving toward the Ohio Valley will pressure
will provide light northerly winds tonight...becoming northwesterly
and then westerly during Friday. Light southwesterly winds will
continue on Saturday. The next system will arrive on Sunday.

&&

Climate...
---this February is wrapping up to be one of the coldest and
snowiest months in our primary climate stations history. The
continued northwest flow of bitterly cold air has left the month
of February a historic month that will be a benchmark mark for
years to come. Below are the coldest months in each stations
history. Temperature records for Buffalo and Rochester go back to
1871...while temperature records in Watertown go back to 1950.



Station: value (f) month (year)

Buffalo 11.6 Feb (1934)
13.4 Feb (1875)
13.8 Jan (1977)
14.1 Jan (1918)
14.6 Feb (1885)
14.9 Feb (1979)
15.5 Feb (1978)
15.6 Jan (1920)
15.6 Jan (1912)
16.2 Jan (1945)



Rochester 12.6 Feb (1934)
13.7 Feb (1979)
14.4 Feb (1875)
14.5 Feb (1885)
14.8 Jan (1918)
14.9 Jan (1994)
15.2 Jan (1945)
15.5 Jan (1977)
15.7 Jan (1981)
16.1 Jan (1920)



Watertown 6.4 Dec (1989)
6.5 Jan (1970)
6.9 Jan (1994)
7.9 Feb (1978)
8.0 Jan (1981)
8.1 Jan (2004)
8.4 Feb (1979)
10.0 Jan (2003)
10.1 Jan (1977)
10.3 Jan (1961)

Current monthly average temperatures are listed on the cf6 climate
product.



---February has also been a snowy month as a persistent track of
clippers within a northwest flow has maintained nickel and dime
snows through the month...this after a significant synoptic storm to
start February. Below are the top snowiest february's on record.
Snowfall records go back to 1884.

Station: snow (in) year

Buffalo 1 54.2 1958
2 49.5 1960
3 45.9 2015 (data through 2/25)



Rochester 1 64.8 1958
2 58.3 1960
3 46.5 2007
4 44.7 2015 (data through 2/25)



--- Buffalo New York has remained at or below freezing since
January 30th. Below is a list of longest consecutive days at or
below freezing in buffalo's history.

Station: run length end date

Buffalo45 daysfeb 8 1977
41 daysmar 8 1978
34 days Feb 10 1985
31 daysfeb 24 1901
28 daysjan 12 1881
27 days Feb 25 2015

--- it is likely that Buffalo remains below freezing the entire
month of February. This has happened once before...in the year 1978.

---Rochester has had 9 days this month with minimum temperatures
falling below zero. Below is a list of greatest number of days
in February with minimum temperatures below zero...

Number year

10 1979
9 2015 (data through 2/25)

The greatest number of days in a month that have minimum temperatures
fall below zero is February 1979...and also January 1994.

The greatest number of days in a winter season in Rochester that
have minimum temperatures fall below zero is 15 days set back in
1884-85.

---Watertown has had 16 days this month with minimum temperatures
falling below zero. Below is a list of greatest number of days in
February with minimum temperatures below zero...

Number year

16 1978
16 2015 (data through 2/24)

&&

Buf watches/warnings/advisories...
New York...none.
Marine...none.

&&

$$

Synopsis...wch
near term...wch
short term...rsh
long term...rsh/Smith
aviation...wch
marine...wch/zaff
climate...Thomas

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