First Clipper of the Season This Week... [Archive]

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Pdogs08

Dec 2nd 2007, 01:51 PM

As part of the true week of winter it will be from the Midwest, Great Lakes and East this week, the first decent Alberta Clipper will occur Tuesday and Wednesday. A synoptic, accumulating snowfall swath is likely to definite from Minnesota to the Eastern seabord in this timespan as you all know.

3" seems good for most areas right now, as I'm sure everyone agree. Maybe a bit more/less locally.

It's oddly interesting, and the following statement strongly supports how timing is indeed everything. These things can cause more traffic headaches for the Wednesday morning rush over, my area for instance in Eastern Ohio, than perhaps a 4-8" winter storm would if it occured on a Saturday afternoon. Reason being obviously, significantly less travel.

I'm now a senior in HS and remember during my sophmore year we had 0 snowdays. It was not that it did not snow, as it indeed was a normal winter season, it just occured bad time-wise. Evening snows ending by 3 am, weekend snows, etc.

A couple/few inches falling at the right time can be far more dangerous than several inches during a quiet period such as a typical Saturday or Sunday afternoon.

I also belive NWS should take this into consideration when issuing advisories/watches/warnings, however that may be taking the concept a bit too far.

Nonetheless, residents will not like what they wake up to early Wednesday across Great Lakes/Upper Ohio Valley....

Mayhem

Dec 2nd 2007, 02:46 PM

We had 2 inches from a clipper last week.

Your statement about the timing and population affected is true and the latter is calculated in the NESIS http://www.ncdc.noaa.gov/oa/climate/research/snow-nesis/ rankings. The former is not, but I believe Paul Kocin had worked on a similar ranking that took things like time of week, holidays, etc. into account as well. But it was not used in the final version of NESIS.

Pdogs08

Dec 2nd 2007, 03:52 PM

I do agree with NESIS and like how they rate/determine the snowstorms and their aftermath. Thanks for that link, Mayhem.

About this week's clipper, I just took a glance at the latest GFS and it dives most of the snow through southern Wisconsin, northern Illinois, Indiana, southern Ohio and West Virginia. On the other hand, the ETA takes the snow further north placing the heaviest in Michigan, Indiana, Northern Ohio and Pennsylvania. I checked some HPC surface pressure charts for the event to see where they place the low and it is difficult to tell from this which model is more accurate at this point. ETA also displays heavier QPF.

Nonetheless, models usually come into pretty nice agreement with clipper systems and the same should occur in this instance over the next day or so.

Pdogs08

Dec 3rd 2007, 01:28 PM

ETA and GFS in bit more agreement today showing heaviest snow through Northern Indiana and Central Ohio. ETA has come into more agreement with GFS. ETA still a bit further north and east with snow zone.

If I were to guess now, I would say 1-4" from Chicago to West Virginia, with 1-2" from around a Kalamazoo, Michigan to Cleveland, Ohio to Pittsburgh, PA line.

Obviously a track 20-40 miles north makes all the difference. I may bit a bit conserverative on my above snow amounts as moisture should be in abundance at both upper levels and surface with this system.

Any takers? Does my forecasting need alot of work?

Mayhem

Dec 3rd 2007, 02:11 PM

With tricky, weak storms like this, it's useful to check out some of the ensemble products. You might find this one usefule Pdogs..
http://eyewall.met.psu.edu/ensembles/java/ModelDisplay.html
The spaghetti plots are all over the place, but the ensemble seems to favor a more southerly solution.
That has been very consistent with most of the thinking with this system.

Pdogs08

Dec 3rd 2007, 04:32 PM

Thanks for the links Mayhem!

Ya the southern solution seems the way to go right now, but obviously is not set in stone yet.

Golfball_Size_Hail

Dec 3rd 2007, 11:49 PM

Wow, I wonder what kind of forecaster I would be now if I cared about weather when I was a senior, instead of caring only about beer and chicks.

MoistureFluxCapacitor

Dec 4th 2007, 01:34 AM

I'm in NW Ohio and went with 1-2" across the central part of my DMA...1" to the north...2-3" for my south areas.

Looking like another Clip on it's heels for early Friday! :) Another 1-2" storm.

Wedge

Dec 4th 2007, 04:10 AM

Pretty energetic system. NWS in Indy mentions good precipitable water values (.5"+), good lift in the snow growth layer and even some frontogenetical forcing...then goes 2" max???? Surrounding offices seem to have a better handle on the system. Looks like a solid 3-5" for Central IN. Warm boundary layer may play a part at the onset.

rellet

Dec 4th 2007, 04:40 AM

I have 2-4" for South Central West Virginia and perhaps more on the highest peaks. I am unsure why the NWS is showing around an inch of snow, 2 at the most with decent moisture, lift, and light upslope snows on the backside of the clipper.

Pdogs08

Dec 4th 2007, 01:36 PM

As of 5:30 Wednesday evening, GFS shows heaviest snow through Indiana, all of central Ohio and into West Virginia eventually. Also shows some decent snow around this area for all of Ohio and into central Pennsylvania. ETA model seems further south with the snow, taking it thru southern Ohio and southern WV and also a bit of a sharper decrease in intensity to north and east. Hard to tell which side the RUC is taking right now, which is good with short term events.

So far, NAM seems to have been more accurate with the snow over the Upper Midwest although possibly not intense enough. GFS is off a bit to the southwest.

Looking at the recent Water Vapor imagery, actually looks like the good moist air extends from about Central Wiscosin down SE thru Michigan and into the Ohio/PA border area. Air seems a bit drier further SW. This could lead to more eastward expansion to current snow shield as it shifts SE. Also adding to this may be the reisidual mositure over parts of eastern Ohio/western Pennsylvania from the recent lake effect.

We'll see how it unflods over the next few hours.

Golfball_Size_Hail

Dec 5th 2007, 03:56 AM

pdogs, don't forget to look at the low level moisture content, that water vapor imagery is for mid-upper levels. It's cute how you explain how things will work to us.

tvwxguy

Dec 5th 2007, 04:03 AM

It's cute how you explain how things will work to us.

I thought the exact same thing! I really do like his attitude though this time around! :cheers:

Golfball_Size_Hail

Dec 5th 2007, 04:07 AM

Yep, keeping focused on just the weather is good.

Pdogs08

Dec 5th 2007, 12:14 PM

Sorry if I sound to much like a forecaster, I'm just trying to throw some ideas out there, although I'm sure many of you already know what I do times ten.

Yes GolfSizeHail, I realize WV is only for mid/upper levels, and was wondering a good indicator of low level moisture, aside from dewpoint levels this time of the year...

Mayhem

Dec 5th 2007, 12:48 PM

Tds are definitely a good start for the LLM. Even using the VIS can give you an idea. Or simple upstream obs. You're doing fine this time Pdogs.

Pdogs08

Dec 5th 2007, 02:06 PM

Sorry to ask, but what exactly are the TDs? I have heard of them before but can quite remember they are/stand for...

I have been using RAP Real-Time Weather quite often lately- using their satellites, models, surface obs, etc, and was wondering if I could find the TDs on this site?

Thanks for any help

Mayhem

Dec 5th 2007, 02:09 PM

TDs are weather slang for dewpoints

Pdogs08

Dec 5th 2007, 02:23 PM

Thats what I thought. Only problem I encounter with dewpoint reading this time of the year is the air is typically fairly dry, or alteast more so than spring/summer obviously, and I have a difficult time determining what dewpoint temps are considered 'moist' in the winter and what is dry in terms of the lower levels.

Mayhem

Dec 5th 2007, 06:26 PM

Always a good option to look at the dewpoint depressions.

Although you have to be careful there. It's a good way to get an idea of trends if you look at a bunch of locations, but if you try to get too specific you will get burned.

Golfball_Size_Hail

Dec 6th 2007, 12:09 AM

Golfball_Size_Hail

Dec 6th 2007, 12:10 AM

nywx10

Dec 6th 2007, 05:06 PM

Check out this link:

http://www.erh.noaa.gov/box/tables/snowfall-meltwater.html

Stormtracker_Tony

Dec 6th 2007, 10:52 PM

You're doing fine buddy, your Santa is a little creepy though ;)

What about my santa???? :D

Golfball_Size_Hail

Dec 7th 2007, 12:19 AM

Wow, is that Santa's soul buring out of him! That's a bit creepier.

Stormtracker_Tony

Dec 7th 2007, 12:58 AM

Wow, is that Santa's soul buring out of him! That's a bit creepier.

that's pretty much him and his clothes burning there...lol...He shouldn't have climbed down into that fireplace while it was operating...I see he forgot to bring these folks gifts too----unless they had burnt up already :D

These small avatars just don't cut it..have to see the full screen image to appreciate all the fine details