Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Buffalo New York
1038 am EDT Friday Mar 14 2014
a broad southwest flow in advance of a storm system over the upper
Great Lakes will provide the bulk of the region with a breezy and
relatively mild day today. The warm up will be short lived though as
a pair of cold fronts will push across our region tonight and
Saturday. The air in the wake of these fronts will return our
Mercury levels to well below normal levels for Sunday and Monday.
Near term /through tonight/...
high pressure centered over the southeast coast and a deep storm
system over the upper Great Lakes will produce a broad southwest
flow across our region today...and this will result in a fairly
significant short term warm up. Temperatures in most areas will
climb well into the 40s...with some 50 degree readings possible in
the Genesee and southern tier valleys. Downsloping will help to
boost readings to 50 or better between Lake Erie and the Chautauqua
ridge as well...while winds off an ice packed lake will keeps things
on the cooler side for Grand Island and parts of iag County.
While not true to definition...the warmer airmass will combine with
Chinook like winds averaging 15 to 30 miles per hour to eat away at the fresh
snow cover over the region.
In terms of sky cover today...clouds east of Rochester will
gradually give way to sunshine while sun will abound over the
The first of two cold fronts will then approach our region from
southern Ontario this evening. Some rain showers will likely
accompany this front as it presses through during the course of
tonight...with the showers changing to snow showers in the deepening
cold air in the wake of the front during the wee hours. After a mild
start...temperatures tonight are forecast to settle to around the
Short term /Saturday through Sunday/...
a clipper low will track north of Lake Ontario which will drop a
cold front across our region Friday evening. This will produce some
showers...which should mainly fall as rain ahead of the front...then
change over to snow as colder air builds in behind the front late
Friday night. Model consensus puts the steadiest quantitative precipitation forecast east of Lake
Ontario and Erie...but this is probably due more to orographic
convergence with temperatures far too warm for any lake induced
instability. Southwest winds will increase with the front...
especially across the Niagara Frontier and along the Lake Erie
shoreline where funneling along the Chautauqua ridge should
enhance flow with gusts to 40 miles per hour Friday evening. Temperatures
will only be modestly cooler behind the front...with lows in the
The region will remain in a cyclonic flow aloft on Saturday a series
of weak upper level disturbances move across during the day. This
will be enough to spark some scattered snow showers on...but these
should generally only bring minimal accumulation to most areas. Highs
will generally be in the upper 30s.
A secondary cold front will drop across the region Saturday
evening...which again may bring some light snow showers given very
limited moisture with the front. It will also usher in another shot
of cold air...with high temperatures on Sunday only in the upper
teens to lower 20s. Meanwhile temperatures aloft will drop down to
around -18c at 850 mb...which will result in some lake induced
instability. The airmass will become progressively drier...however
there will be a narrow window for lake effect snow to develop east
of Lake Ontario Saturday night where sufficient instability and
moisture are in place. The mobility of any lake effect band will
limit accumulation at any one location...but a few inches are
possible east-southeast of Lake Ontario on Saturday night. By Sunday lowering
equilibrium levels will cause any lingering lake effect snow to be
very localized. It is Worth noting temperatures beneath the low
equilibrium level will be cold enough to support dendritic snow
growth...so it is possible a Narrow Lake effect snow band will
develop on a localized convergence boundary. Given the localized
nature of this potential and will maintain only chance probability of precipitation.
Long term /Sunday night through Thursday/...
low pressure will develop near the Carolinas Sunday night...with 12z
guidance packages continuing to track the low just far enough to our
south to keep our area dry Sunday night and Monday. Instead...high
pressure across eastern Canada is forecast to ridge into our
region...which will bring fair weather but below normal
temperatures through early next week.
12z guidance has generally slowed on the next system...with a
consensus timing pushing its arrival back to mid-week. The slowest
guidance (12z ecmwf) keeps US dry until early Thursday. The forecast
will take a consensus approach...but keep a rather long period of
chance probability of precipitation to convey the significant timing uncertainty. The system
(eventually) will lift across the Great Lakes region. This track
would initially bring warmer air into the region...with modestly
colder air behind the system. Temperatures could rise considerably
warmer than forecast in the middle-week time frame...or not...depending
on the timing and track of the low. Either way...there is no
prolonged warm up on the horizon...but at least temperatures should
at least be closer to normal for the latter portion of next week.
Aviation /15z Friday through Tuesday/...
VFR conditions will be found across all of western and north central
New York through the afternoon and into the early evening hours. The
only issue will be gusty southerly winds that could reach to 35
Tonight...the first of two cold fronts will push across the region.
While VFR conditions will initially remain in place...there will be
some rain showers and lower strato-cumulus to mark the passage of the
front. Late tonight...ceilings are forecast to lower to MVFR levels
across most of the region with some IFR ceilings possible across the
higher terrain of the southern tier.
Saturday and Sunday...VFR/MVFR with a chance of snow showers.
Tuesday...VFR/MVFR with a chance of snow showers.
a warm front will lift across the eastern Great Lakes this
morning...ushering in a period of stronger southwesterly winds for
the day...before a cold front crosses the area tonight. In the wake
of the cold front...winds will veer to westerly and diminish again
Friday night and Saturday.
Small Craft Advisory will be in effect for the nearshore waters of
Lake Ontario. The higher winds and waves will spread farther to the
east this afternoon...thus a Small Craft Advisory will be in effect
through Saturday night for the south Central Lake Ontario nearshore
waters from thirty Mile Point to Sodus Bay.
there are some ice jams in place on the Buffalo creeks and
elsewhere. At this point...flows are light and ice jams are stable.
We have not received any reports of significant flooding...however
the gauge on Buffalo Creek at Gardenville remains steady at flood
stage. The situation will be continue to be monitored by local
emergency management...but at this time flooding is not anticipated.
Temperatures this afternoon will generally warm into upper 40s
across the headwaters of the Buffalo creeks...with some 50s likely
across The Finger lakes region. This will result in some snow
melt and cause flows to increase. This will result in 150 to 175
thawing degree hours...which is typically not enough to result in
significant ice break ups. However...given the jams already in
place...this does bear watching as flows will likely increase...
especially in areas where ice jams are in place.
Marine...Small Craft Advisory until 3 am EDT Sunday for loz043.
Small Craft Advisory until 8 am EDT Saturday for loz042.