Updated FD:
.NEAR TERM /THROUGH TONIGHT/...
Lake effect band that was slow in developing off Lake Erie with
minimal amounts through 5 AM this morning *quickly* developed 5AM to
7AM and has been very intense since then with multiple hours of 3"
per hour rates observed in the Buffalo Metro. Band wavered north
earlier across Northtowns toward the border of Niagara county, but
then quickly settled back to its current locked in position
Buffalo downtown to the Buffalo Airport and to Akron and
Pembroke in western Genesee county. BUF VWP shows well-aligned
240-250 flow and inversion heights around 7kft. As we suspected
a couple days ago, SLRs have been quite high well over 20:1 as
all the bulk of the convective layer above cloud base resides
within the DGZ. Model soundings and output underplayed the
higher SLRs. No change to large scale in terms of synoptics with
departing trough aloft this morning and sharpening trough
crossing the Ohio Valley tonight that eventually helps develop a
coastal low toward daybreak Friday. At the sfc, lake induced
trough remains lined up across Lake Ontario to western Great
Lakes through tonight. Over-water instability more than
sufficient with 850mb temps around -14C (with the lakes about
+3C). The details...
Off Lake Erie...
Based on radar and VWP trends, SW flow 240-250 persists through
early afternoon. A bit of shear in convective layer and some
lowering of inversion could cut down on band intensity after 1-2 PM,
Still though, with such high SLRs, several inches of snow will still
occur through the afternoon hours. Totals essentially since 530 AM
this morning are already pushing a foot at the Buffalo airport and
other locations in central the Buffalo Metro in the Downtown to
airport to Pembroke corridor. Winds in lake convective layer backing
some mid to late aftn may push the main focus for the band back
across the Northtowns and toward Erie/Niagara county line. Trough
across the Ohio valley this evening will then increase synoptic
moisture and likely to cause lake snows to intensify before winds
shift to the west behind this trough late tonight, likely not until
midnight. Thus the band will continue to focus across the Buffalo
metro area this evening before shifting southward to the Western
Southern Tier late tonight.
Off Lake Ontario...
Snow has been more widespread much of this morning, but sharper
convergence band is beginning to develop. Mesoscale guidance shows
this band getting better organized through late afternoon so that
seems on track. A very narrow band across northern Jefferson County
will likely extend to the northwest corner of the Tug Hill as well
(Carthage/Copenhagen). Thus far, snowfall rates generally have been
under an inch per hour, but expect these to increase rest of today
with snowfall rates of 1-2 inches an hour can be expected. Lewis
County remains in the warning, however it`s important to note that
there will not be much snow at all across the southern half of the
county. Weakening winds will cause snow to contract closer to the
lake later tonight. Increase in synoptic moisture in advance of a
trough will maintain lake snows which will likely clip Jefferson
County at times. At this time, storm total forecast off Lake Ontario
remains pretty much in tact.
..ERIE COUNTY DEPEW 14.0 IN 1207 PM 01/06 42.91N/78.70W BUFFALO INTERNATIONAL ARPT 13.1 IN 1156 AM 01/06 42.95N/78.72W 1 SE HARRIS HILL 11.0 IN 1100 AM 01/06 42.97N/78.67W 2 N BUFFALO 7.5 IN 1027 AM 01/06 42.93N/78.86W ..JEFFERSON COUNTY WATERTOWN 6.2 IN 1200 PM 01/06 43.97N/75.91W
