Area forecast discussion
National Weather Service Buffalo New York
336 PM EDT Friday may 24 2013
Synopsis...
Canadian high pressure building across the Great Lakes will bring
mainly dry and cool conditions this weekend. Temperatures will
rebound back to above average next week.
&&
Near term /through Saturday/...
regional radars showing back edge of precipitation pushing through
the Eastern Lake Ontario region. Some lingering very light rain or
drizzle still continuing across portions of The Finger lakes and
even as far west as the Genesee Valley. Clearing trend has been
non-existent this afternoon except for the western half of Lake
Ontario. This clearing now beginning to come onshore into northern
sections of the Niagara Frontier. This trend would suggest that
most of the Niagara Frontier will see clearing before sunset this
evening...but most other areas will likely remain cloudy into this
evening.
Temperatures will be a concern tonight. Dense cloud cover has held
temperatures down this afternoon with readings along the southern
tier still in the 30s. Despite some gradient tonight...feel with
only a few degrees to go to reach freezing...a freezing warning
looks reasonable for the three southern tier counties. Depending
on how much clearing can take place tonight and how much winds
slacken tonight it is possible that other frost/freeze headlines
might be needed...although frost development looks less likely
with at least some gradient expected.
Saturday...models in closer agreement with the slow progression of
the upper low. Associated precipitation looks to back in from the
east and may impact areas east of Lake Ontario. Bulk of the area
will see plenty of sunshine. With cold air mass centered over the
area we will only see highs in the middle 50s to lower 60s...although
cool will be an improvement over todays readings in the 30s and
40s.
&&
Short term /Saturday night through Monday night/...
Saturday night a closed upper level low will be sitting over New
England...with a cold northwest flow across the eastern Great Lakes.
Moisture and precipitation around this area of low pressure will
largely be confined to areas just to our east...though a few light
showers may brush by our north country. By Sunday morning cold air
under this area of low pressure will back slightly westward such
that -2c air at 850 hpa will be found across the western foot hills
of the Adirondacks and would not be surprised if a few snow flurries
mixed in with the light rain showers.
Away from the north country mainly clear skies will be found and
cold with a northwest wind. The gradient between high pressure
nosing southward over the central Great Lakes and the closed low
over New England will be about the same Saturday night as Friday
night. Current thinking is that freezing temperatures will be a
concern again across the southern tier...and that the light winds
will limit the frost formation. Closer to the lakes is where the
warmest overnight lows will be found with upper 30s to around 40 for
nighttime lows.
There will be a little improvement Sunday as the closed low slowly
lifts through northern New England. This movement should be enough
to keep our area dry with lingering clouds brushing by the eastern
portions of the north country. Elsewhere plenty of sunshine will
again be found across areas south of Lake Ontario and with 850 hpa
ranging from +2 to +4 our highs will be a couple degrees warmer than
Saturday...with highs in the low 60s. A light northwest wind will
again be found across the County Warning Area.
Sunday night will be dry and winds backing to more of a southwesterly
flow. While freezing temperatures will be very spotty across the
southern tier and inland north country the lighter winds and relaxed
pressure gradient will allow for some patchy frost.
On Monday surface high pressure will slide into the region.
Subsidence with this feature will bring a dry Memorial Day and
abundant sunshine across the region. Though a Blue Sky temperatures
will still fall shy of normal with afternoon highs in the middle to
upper 60s. Dewpoints will also be low...in the middle to upper 30s
which will bring low relative humidity values. Dry conditions will continue through
the night Monday with lows dropping back into the 40s.
&&
Long term /Tuesday through Friday/...
this time period will be mainly dry...with building heat and
humidity. There is still a bit of uncertainty as to when a warm
front lifting northeastward will cross the eastern Great Lakes
region. The 12z GFS/12z Canadian operational model runs are a little
faster than the 12z European model (ecmwf)...with a passage Tuesday...while the
European model focuses more upon Wednesday. Will bring low chance
probability of precipitation for showers and thunderstorms across the region Tuesday
night-Wednesday night.
Before the frontal passage it will be comfortable with low dewpoints
and seasonable late may temperatures.
After the warm front passes humidity will begin to build while
temperatures each day will likely be a degree or so warmer. By
Friday afternoon highs will be well into the 80s across the region.
The building ridge over the region Thursday and Friday will likely
cap any afternoon showers and thunderstorm development...and thus we
will maintain a dry forecast for now.
&&
Aviation /20z Friday through Wednesday/...
widespread MVFR to IFR conditions prevail across the area early
this afternoon as plenty of moisture lingers behind the departed
cold front. The showers will slowly end from west to east during
the day as the upper level trough moves slowly east. IFR ceilings will
improve to MVFR as the rain tapers off. Later this afternoon and
during the evening...ceilings should lift to VFR...then scatter
out...especially across western New York. Clouds will continue to
thin out tonight as drier air works in from the west. The
exception to this general trend will be east of Lake Ontario where
clouds and possible showers will linger in the wake of the low
that will be stationed off the New England coast.
Outlook...
Saturday through Wednesday...VFR.
&&
Marine...
unseasonable conditions are in place over the lower lakes region as
cold air advection is ongoing within a deep trough axis. Efficient
northwesterly flow sustaining low end advisory level conditions...
especially on Lake Ontario. These conditions will persist into the
overnight hours on Lake Erie and the western end of Lake Ontario...
before winds begin to diminish. Small craft conditions may redevelop
in Lake Erie Saturday afternoon.
The modest northwesterly flow will persist into Saturday on the
eastern end of Lake Ontario therefore maintaining the low end Small
Craft Advisory conditions there.
Conditions on the lakes will improve by Sunday and Monday and high
pressure moves overhead...with no marine issues foreseen
&&
Buf watches/warnings/advisories...
New York...freeze warning from 2 am to 7 am EDT Saturday for nyz019>021.
Marine...Small Craft Advisory until 7 PM EDT this evening for lez020.
Small Craft Advisory until 4 am EDT Saturday for lez040-
041.
Small Craft Advisory until 7 PM EDT this evening for
loz030-042.
Small Craft Advisory until 2 PM EDT Saturday for
loz043>045.
&&
$$
Synopsis...tma
near term...tma
short term...Thomas
long term...Thomas
aviation...tma
marine...tma
