Topic police at your service. :wink:
Eastern NoAm Weather 2008-09
- Thread starter Harvey
- Start date
Perhaps I was too fast in responding. I'm not sure we want a 20-page thread by the end of the season, though. Dividing by month seems like a good compromise. It will be easier to find retrospective posts if it's not one huge thread. But it's not a clear-cut call; admin can change it back if he wants.
powderfreak
New member
DECEMBER 11-12 STORM FORECAST PRIMARILY FOR CENTRAL/NORTHERN VT
Forecast: Snow breaks out later this evening and becomes heavy at times after midnight. Snow will mix with and change to sleet for a time during the early morning hours (4-7am), especially along and SE of a line running from Binghamton, NY to Sherbrooke, QC (includes the Green Mtn spine and possibly BTV). Some freezing rain may even mix in from Rutland Mixed precipitation goes back to all snow as the low passes to our east between 7-10am. Snow continues tomorrow before tapering off during the late afternoon.
Total accumulations for Central and Northern Vermont...widespread 7-14" with those who experience extended mixing seeing the lower value, and those who see all snow reaching the higher value. If for some reason it doesn't sleet north of Rutland, places in Addison and Washington counties could see locally higher amounts.
Discussion:
Precipitation will be slow to move northward, but make no mistake, we are in for a heavy precipitation event here. Basin QPF averages should be greater than 1" across all of Vermont except maybe a portion of far NW Franklin Cnty. Central and eastern Vermont is looking at an average of 1.5"...maybe even some 2" amounts further SE. What type of precipitation won't be fully determined until its actually happening...the thermal profiles are making my head spin.
Looking at the satellite presentation this afternoon (image from 1pm), it was obvious that this is rapidly becoming a major mid-latitude cyclone. And talk about tapping deep tropical and Atlantic moisture...note the southerly inflow stretching to lower Central America as well as the massive on-shore flow along the entire eastern seaboard.
http://tinyurl.com/5lujem
We will have no problem with QPF with this type of inflow over-top a steeply sloped thermal gradient. This baroclinic zone will promote intense frontogenic forcing with bands of heavy precipitation inhabiting the larger shield. If we can stay snow, snowfall rates of 1-2"/hr are likely after midnight tonight.
This is what we are working with right now, and this mod/hvy precipitation will continue to slowly lift northwest this evening...FYI- the Intellicast radar certainly has one of the better resolution p-type schemes out there:
http://tinyurl.com/6sxoto
Snow has been trying to develop from western NY back to Ohio this afternoon under strong divergence in the right-rear quad of the upper level jet, and it is finally starting to moisten the lower levels. Later tonight, the best upper level divergence will swing over the North Country in tandem with the low/mid level forcing...the synoptics are looking good at this point.
P-type? Going to start as snow everywhere but later tonight as the low crosses Long Island into SNE, pesky above freezing layers begin to show up from 900mb to 700mb. The soundings from BTV indicate some minor 0C-1C warm air in the vicinity of 875mb...but to our east we've got a more pronounced warm layer in the soundings indicating we will go to sleet for a time up and down the Green Mtns. The caveat is that heavy precipitation from synoptic factors could mix out the warm layer through cooling caused by melting snowflakes...and we end up with a column that remains barely below freezing.
For the forecast, I've used the H10-H7 284dm thickness contour as the dividing line between snow and sleet as this best maps the current situation. Per the SREF (short-range ensemble forecast), the farthest NW this contour gets is to the Binghamton, NY to Sherbrooke, QC line...and encompasses the Green Mtns for roughly 2-3 hours of the event before getting yanked east.
Snow then continues at a light to moderate clip into Friday afternoon. Winds do not seem to be a huge issue with this storm, though could see some 30-40mph gusts in the higher elevations...but I'm not concerned with wind hold at this time.
Get out there and enjoy it!
-Scott
Forecast: Snow breaks out later this evening and becomes heavy at times after midnight. Snow will mix with and change to sleet for a time during the early morning hours (4-7am), especially along and SE of a line running from Binghamton, NY to Sherbrooke, QC (includes the Green Mtn spine and possibly BTV). Some freezing rain may even mix in from Rutland Mixed precipitation goes back to all snow as the low passes to our east between 7-10am. Snow continues tomorrow before tapering off during the late afternoon.
Total accumulations for Central and Northern Vermont...widespread 7-14" with those who experience extended mixing seeing the lower value, and those who see all snow reaching the higher value. If for some reason it doesn't sleet north of Rutland, places in Addison and Washington counties could see locally higher amounts.
Discussion:
Precipitation will be slow to move northward, but make no mistake, we are in for a heavy precipitation event here. Basin QPF averages should be greater than 1" across all of Vermont except maybe a portion of far NW Franklin Cnty. Central and eastern Vermont is looking at an average of 1.5"...maybe even some 2" amounts further SE. What type of precipitation won't be fully determined until its actually happening...the thermal profiles are making my head spin.
Looking at the satellite presentation this afternoon (image from 1pm), it was obvious that this is rapidly becoming a major mid-latitude cyclone. And talk about tapping deep tropical and Atlantic moisture...note the southerly inflow stretching to lower Central America as well as the massive on-shore flow along the entire eastern seaboard.
http://tinyurl.com/5lujem
We will have no problem with QPF with this type of inflow over-top a steeply sloped thermal gradient. This baroclinic zone will promote intense frontogenic forcing with bands of heavy precipitation inhabiting the larger shield. If we can stay snow, snowfall rates of 1-2"/hr are likely after midnight tonight.
This is what we are working with right now, and this mod/hvy precipitation will continue to slowly lift northwest this evening...FYI- the Intellicast radar certainly has one of the better resolution p-type schemes out there:
http://tinyurl.com/6sxoto
Snow has been trying to develop from western NY back to Ohio this afternoon under strong divergence in the right-rear quad of the upper level jet, and it is finally starting to moisten the lower levels. Later tonight, the best upper level divergence will swing over the North Country in tandem with the low/mid level forcing...the synoptics are looking good at this point.
P-type? Going to start as snow everywhere but later tonight as the low crosses Long Island into SNE, pesky above freezing layers begin to show up from 900mb to 700mb. The soundings from BTV indicate some minor 0C-1C warm air in the vicinity of 875mb...but to our east we've got a more pronounced warm layer in the soundings indicating we will go to sleet for a time up and down the Green Mtns. The caveat is that heavy precipitation from synoptic factors could mix out the warm layer through cooling caused by melting snowflakes...and we end up with a column that remains barely below freezing.
For the forecast, I've used the H10-H7 284dm thickness contour as the dividing line between snow and sleet as this best maps the current situation. Per the SREF (short-range ensemble forecast), the farthest NW this contour gets is to the Binghamton, NY to Sherbrooke, QC line...and encompasses the Green Mtns for roughly 2-3 hours of the event before getting yanked east.
Snow then continues at a light to moderate clip into Friday afternoon. Winds do not seem to be a huge issue with this storm, though could see some 30-40mph gusts in the higher elevations...but I'm not concerned with wind hold at this time.
Get out there and enjoy it!
-Scott
One of the things I miss least from the East:
http://www.firsttracksonline.com/News/2 ... nd-Skiing/
http://www.firsttracksonline.com/News/2 ... nd-Skiing/
jasoncapecod
Well-known member
I need to resize the photo :shock: I wish that damn iching would stop :wink:
by the way MRG only recieved 8" before the rains came..
Perhaps powderfreak or someone else can explain the precise dynamics, but I have NEVER in 32 years of skiing seen an ice storm anywhere in the West. My understanding is that you need warm air aloft that starts falling as rain into a colder air mass below that freezes it before or as it hits the ground. We do get extreme weather out here. At New Year's 1997 it rained to 12,000 feet for 3 days, trashed Squaw Valley and Yosemite Valley with floods and reformed a lake in the Central Valley that had not existed since the first dams were built 100 years before. So the snow level can fluctuate a lot, and you might get snow, sleet or rain, but not ice as far as I can tell.
Patrick
Well-known member
Harvey44":lulrlc63 said:
I, once again, disagree with Tony. :roll:
Concern about the how long the thread is? I guess he didn't notice both classic Eastern threads started by laseranimal on TGR.
He started a new thread on October 20th after people continued posting on the original Eastern Roll Call thread started last year.
Second Annual EC Roll Call Thread started on October 20th.
Pages: 80
Posts: 1,993
Views: 50,385
First EC roll call thread (Nov 14, 07 - Oct 20, 08)
Pages: 120
Posts: 2,996
Views: 111,477
Oh yeah, I forgot...welcome Powderfreak!!!
Topic remerged by majority vote.
Not sure why that didn't happen last week. I'm sure admin's knee was a greater priority.
J.Spin
New member
I'm not sure why people don't hear about them in the Western United States, perhaps because they don't typically affect the major population centers, but we had various freezing rain events and advisories while we were out in Montana. I don't know how many of them I documented, but here's at least one I mentioned in my Lost Trail report from November 26th, 2005, it's mentioned in the first paragraph of the text and appeared to come after a lengthy freezing fog inversion period. We never saw any accumulations as substantial as what Central New England/New York state just received however.Tony Crocker":ok7wrbg5 said:
-J