Friday, November 21, 2008

3PM Snow Update

Sorry this update is a bit later than I promised. I ran into some difficulties with making the snow map.

The lake effect has been pretty disorganized through the day as winds haven't really aligned themselves well yet. The models showed this happening relatively well. This disorganization should continue until about sunset, when things really start to get going. I am expecting multiple bands of lake effect to form, with probably two main bands. They will move around a bit overnight, so plenty of areas should see some high snow totals. Here is what I am thinking for amounts by 9AM tomorrow morning:

As with any lake effect event, not every area within each contour will get that amount of snow and the variance from one spot to another can be very large. So, that snow map shows the most likely amounts that are to occur in each area.

Tomorrow, the lake effect should calm down as the day gets into the afternoon. Additional accumulations tomorrow will likely be anywhere from 1-4" in the white and light blue areas, to 3-7" in the darker blue.

Quick Friday Morning Update

Only have time for a quick update this morning. Expect a more complete update this afternoon between 1:30-3.

The Lake Effect Snow Watches have been replaced with warnings and advisories. Which counties are under what is shown below. I honestly can not begin to fathom why Tompkins County is NOT under at least an advisory. The NWS forecast for Ithaca is calling for 1-2" of snow today, then another 4-6" overnight and 2-4" more on Saturday. That is a total of 7-12". That is even beyond advisory criteria...we should be under a warning. The amounts forecast by the NWS for Groton are even higher.

Make sure to tune back this afternoon. I will be updating as soon as I can.

Thursday, November 20, 2008

More Lake Effect Coming!

Lake effect snow watches have been posted for 2/3 of the grotonweather forecast area, so I decided to go with a blog entry tonight instead of a normal update.. In general, I think I will mostly blog-update during this event, which means you will see the blog up when you come to the site until Sunday morning. As always, you can get to the main page by cicking the banner at the top of the page, or by following the 'Homepage' link under 'Grotonweather Pages'. The homepage currently isn't updated, but will be later tonight or tomorrow as well though. To the weather now:

A very weak and moisture starved storm system has been moving across the area today. This storm will turn winds more northerly tonight and then northwesterly for Friday and Saturday. The airmass that is moving in is pretty much perfect for a big lake effect snow event. I can not remember the NWS posting Lake Effect Snow Watches for areas so far away from the Lake, yet Southern Cayuga and Cortland Counties are both under watches. Admittedly, this is another one of those situations I so often talk about where something is issued for Southern Cayugan and Cortland, but really applies for Groton and Northeastern Tompkins County as well. That is why, on the map below, I have shaded the counties under the watch, as well as where I think the best shot for heavy snow is.

The exact location of the band(s), as usual, is a tough forecast. Normally with this kind of set up, there seems to be a heavy band across Northern Cayuga County, stretching right through Syracuse and into Madison County. A second, slightly weak band, likes to set up in Southern Cayuga and Northern Cortland counties, clipping the Groton area. Of course, these bands aren't always in the same position, and 10 miles difference can make the difference between 2" or 12".

My best guess at amounts are this: Someone in the northern half of the pink area will get well over a foot, possibly upwards of 2 feet by Sunday morning. In the southern half of the pink, someone will get a foot.

The weather models I had available to me this afternoon were from early this morning. As more recent models come in, I will try to pin down amounts a bit more. Stay tuned!