SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
...Potentially Significant Lake Snows Wednesday night and Thursday...
Sfc ridge to our south departs off the Mid-Atlantic with developing
southwest flow across the Lower Lakes Tuesday night ahead of the next
system. Dry and not quite as cold with lows in the 20s to low 30s by
daybreak Wednesday.
Mid-level trough and sfc low will approach the eastern Great Lakes
on Wednesday. 12/02 guidance suggests that the main cold front will
cross the area with little fan fair Wednesday morning (not much
precipitation). However, as the aforementioned low draws near Lake
Huron by days end a secondary sharper front is advertised to plow
east across Western NY. Much colder air, to the tune of -14C/-16C at
H850 is advertised under cyclonic SW flow to then channel up Lake
Erie. This will likely induce a lake response beginning first off
Erie and then the same will occur a bit later off Lake Ontario.
BUFKIT profiles suggest that there will likely be sufficient
moisture extending through most of the DGZ along with equilibrium
levels in the neighborhood of 6-7K feet. One other thing to note, it
will become quite windy with gust up to 40 mph, especially NE of the
lakes through Wednesday evening. At this point, confident enough
that there will likely be accumulating lake snows ENE of the Lakes
beginning Wednesday evening into Thursday to mention it in the HWO.
Otherwise, Wednesday look for temps to peak in the upper 30s to low
40s then rapidly fall off Wednesday evening. Temps will then be
found in the 20s by sunrise Thursday.
Pronounced cold advection around the south side of a trowal is
evident across WNY by early Thursday morning. H85 temperatures drop
like a rock into the -12 to -14C range through the day with large
scale moisture secluding in the surface to 850 hPa layer around the
trowal and over Lake Erie. Soundings suggest impressive lake induced
instability, some synoptic moisture remaining, and a fetch of the
entire lake to work with through the day Thursday. Likewise, GFS and
Canadian Global wind fields favor confluent flow down the length of
the lake with a long axis of the lake band likely to come into WNY
somewhere near Buffalo for at least a solid portion of the day
Thursday. This is the time to watch for potential SIGNIFICANT lake
effect snow accumulations in the metro Buffalo area. The same things
can be said for the Watertown area on the east end of Lake Ontario...
just lagging about 6 hours.