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Area forecast discussion 
National Weather Service Buffalo New York
733 PM EST Thursday Feb 26 2015

with the exception of some Minor Lake effect snow along the
immediate Lake Ontario shoreline tonight through Friday...western
New York should see uneventful but continued cold weather Friday 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 Friday/...
light snow has begun to taper off across the area this evening with
the passage of an upper level shortwave...however light returns
continue to be noted upstream and expect a couple more hours of very
light snow across much of western New York with little or no
accumulation. Light snow will likely hang on a little longer along
Lake Ontario where light upslope northerly flow will help maintain
Shallow Lake effect snow showers through a good portion of the
night. Again...any snow that occurs should be fairly light with
accumulations not amounting to more than a half inch or so. Looking
at overnight lows...a continuation of the anomalously cold airmass
will promote lows near zero f...and below zero over the southern
tier and eastern Finger Lake region.

On Friday...the area will generally be under the influence of the
well established Ohio Valley ridge...with some moisture trapped
below about 2000ft. This will lead to varying low cloud
conditions...with a slow improvement throughout the day. Ongoing
weak lake effect should be confined to Lake Ontario itself by
this time in Tea-Kettle fashion...possibly edging into the
Eastern Lake Ontario shoreline during the afternoon.


Short term /Friday night through Sunday night/...
lingering cold will close out February with some weak lake effect
east of Lake Ontario then we will open March with a snowstorm while
temperatures rise back toward normal. Looking at the details Friday
night...Arctic high pressure will center just south of New York
state continuing to support below normal temperatures with clear
skies and light winds. Temperatures are expected to drop below
zero...hopefully for the last time...across the forecast area with
the coldest temperatures reaching toward ten below across the western
southern tier. Winds are expected to be less then 5 knots near the
center of the surface high which should preclude any wind chill
headlines. Otherwise...the cold airmass will continue to support
some weak lake effect snow southeast of Lake Ontario. A low capping
inversion...some surface to 925mb directional shear and ice cover on
the east end of the lake should keep lake snows limited to an inch
or less overnight.

Saturday and Saturday night the surface high will shift just south
of New York with strong ridging extending over the forecast area.
This will allow for a good deal of sunshine with generally dry
conditions with the exception for a weak band of lake effect snow
shifting north along the eastern end of Lake Ontario. Again lake
effect parameters are not favorable for any significant snows.
Around an inch may be possible east of the lake. Temperatures will
remain below normal only warming to near 20 Saturday then dropping
back into the single digits under mainly clear skies Saturday night.
This persistent cold will almost certainly close out February 2015 as
one of...if not the coldest month in the recorded history of our
climate sites which covers 144 years in Buffalo and Rochester...and
65 years in Watertown. More details in the climate section below.

Confidence for another round of accumulating snow has continued to
increase as 12z global models continue to advect a large plume of
Gulf moisture northward across the Ohio Valley and northeast Sunday
and Sunday night. This moisture will be pumped northward and into a
lingering Arctic airmass on the backside of the Arctic surface high
shifting off the East Coast. The surface forcing looks very weak with
no clear sign of a closed circulation but a broad shortwave trough
at 500mb with attendant vorticity maximum along with support from the left
exit region of an 850mb jet will provide enough lift to support a
widespread light to moderate snow fall. Suite of model quantitative precipitation forecast shows
differences of near a half inch of liquid which yields low
confidence in a snow forecast at this range. European model (ecmwf) is on the higher
end with the GFS running between the ec and CMC. Warmer temperatures
aloft shown in the guidance would also hold snow ratios down during
much of the event until colder air circulates in behind the surface
wave later Sunday night. This will bear watching though as higher
snowfall amounts would require another round of winter weather
headlines. Temperatures Sunday will climb toward 30 then only slip
into the 20s Sunday night.


Long term /Monday through Thursday/...
any lingering snow on Monday should taper off from west to east as a
now well-defined surface low to our east shifts across the Canadian
Maritimes and Pacific-based high pressure builds across the lower
Great Lakes. This Pacific based high will help keep temperatures
closer to normal Monday rather than the below normal temperatures we
became used to in February from numerous Arctic highs. Dry
conditions Monday night at the high moves overhead with clearing
skies and light winds pushing temperatures back below normal.

Our next storm system will come Tuesday into Wednesday as a strong
500mb shortwave and attendant vorticity maximum ejects 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 /01z Friday through Tuesday/...
MVFR/localized IFR conditions in -sn associated with a passing upper
level disturbance will improve over the next couple of hours as the
shortwave lifts off to the east. Light northerly upslope flow will
keep a few lingering -shsn along/just south of Lake Ontario
overnight with MVFR ceilings before the advection of increasingly dry
air brings VFR conditions into wny after 12z Friday. Lingering westerly
flow will keep lake clouds with VFR/MVFR ceilings in play east/southeast of Lake
Ontario into Friday afternoon.

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.


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.


---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

---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 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

---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.



near term...wood/zaff
short term...Smith
long term...Smith

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