Well, the GFS is slowly coming around to what my original thoughts were 8 days ago were on this storm...and everything I spoke about in my video a few days ago seem to be finally come true in reality and as we get closer to the time of the storm on the models. This is Student Meteorologist Kyle Elliott, and I have much to talk about tonight in a two-pronged storm discussion: written part first, then my final snowfall map for the storm. So, where to start? Well, I think a good place to start would be with the GFS model since that was the model in error that I was attacking in my video a few days back. In the video, I had said that a trough rarely flattens out to a zonal flow as it comes east, especially with the incredible amount of energy and vorticity at the 500mb level being displayed at the same time on the same model. Low and behold, the GFS is now showing a sharpening trough as it comes east...which is now coming very close to being into collaboration with the NAM model. It is still not as amplified as the NAM, but the most recent 18z run of the GFS has been the closest the NAM model I have seen yet. And, speaking of the NAM, the very new 00z run that has just come out will indeed make a lot of meteorologists go back to the drawing board: it is now more amplified than ever and picking up on the fact that the current satellite/radar composite is much stronger/farther north than forecast to be at this time by the model runs yesterday. Also, the new NAM picks up on the fact that the energy in the Midwest may actually try to phase with some of the leftover energy trudging through the Southeast and southern Mid-Atlantic. This all seems very reasonable given the fact that the current radar shows a connected area of precipitation running from Georgia the whole way back into the Plains states...something the models did not have happening this soon. Now, onto a few points about the snowstorm coming to the Mid-Atlantic and Northeast...
1) I am not relinquishing my idea of a 5-8, 6-10" snowstorm for areas from Baltimore points north and east. With the latest NAM run, this idea seems valid as even Baltimore, given 15:1 snowfall ratios, seems at least 5" on the model run. But, of course, there is an explanation for why this is happening and why at least I believe this storm will bring the best snows farther west than the post-Christmas storm. First, the trough axis is about 150 miles farther west than the post-Christmas storm...and the vorticity max closes off over Indiana and Ohio. During the Christmas storm, it closed off over North Carolina and moved northeast...keeping the heaviest snow confined to the I-95 corridor points east. As you can see, this time it is closing off much farther north and west than that storm. Normally, as I have observed, the best snows occur right out in front of the vort max, or the right front quadrant of the Jet, which appears like it may start setting up in the area of Warrenton, VA, northward to Hagerstown, Md, to State College, PA. Therefore, I expect at least 2-5" of snow even in these areas with an expansion of 5-8" amounts in Baltimore, Parkton, and York and Lancaster. It all makes sense that this would be the logical way things should play out given the 500mb setup. Things still have time to change, but I am fairly confident they can only get better as the trough seems to want to be digging deeper on the latest models runs. Therefore, this will be my final forecast for the storm with only minor updates/changes in the overall forecast from here points forward. I may go down with the ship, but that is just going to have to be the case this time as I do not want to change my original thinking.
2) Let me farther explain the storm and how its going to come about. Basically, we have a two-pronged attack. First, we have a storm in the Midwest and a storm over the Southeast. The storm in the Midwest, which is by far the weaker one, will try to attack the Ohio River Valley as one low pressure center heads west of the Mountains. The other low pressure center, centered now over the northern Gulf of Mexico, will continue to scoot across the northern Gulf Coast tonight into tomorrow before going off the Carolinas late tomorrow afternoon. From there, things get interesting. Models as one time were trying to make too much of the storm in the Midwest while basically trying to kill the vast amount of moisture plaguing the Southeast with the major winter storm they're receiving tonight. I have always scratched my head as to why this moisture seems to nearly collapse, and I am glad I did. The new 00z NAM, while it does weaken the moisture, is finally picking up on the fact that it will not weaken nearly as much as once thought. Also, it is picking up on the fact that the moisture will want to continue on its northeastward journey it is currently taking...instead of moving straight east. All of these factors serve to feed my original opinion that the coastal storm will be further west and stronger than models have been depicting in the last few days.
3) As the first storm center attacks the Ohio River Valley, a transfer of moisture will once again occur to re-intensify the coastal storm off the Delmarva Peninsula. In a situation similar to 1983 and vaguely resembling 2003, the primary storm on the coast will quickly take over and bomb out. If what I said above in my post is correct, this transfer should take place sooner rather than later as the 00z NAM depicts for two specific reasons. First, the storm center on the East Coast should be farther west/closer to the 2nd storm heading toward the Cincinnati area. This should serve to lead to a quicker phase as the storm systems will be slightly closer to each other. Also, with a stronger coastal storm, that should be able to enhance the trough coming eastward and in a sense pull it farther south like the 00z NAM shows. This would serve to amplify the entire storm system and bring heavier snows farther south and west into the D.C. and Baltimore areas. Therefore, I will go 3-6" in D.C. and 5-8" in Baltimore, York, and Harrisburg, while saying 6-9" for Lancaster and at least 7-11" for Philadelphia. As the storm takes off moving northward along the coast, New York City points north and eastward should do extremely well with this storm. With the abundant amount of moisture and convective nature I believe the storm will take on, somebody will see easily more than a foot of snow with this thing. The one player that may cut down on totals is the fact that this storm will be a fast mover...therefore not bringing nearly the crippling amounts of snowfall that the post-Christmas storm did. I still believe, though, that precipitation will be heavy enough to provide a swath of 10"+ of snow to places in southeastern New York State upwards through western CT and MA. Even VT, NH, and Maine could get a heck of a snowstorm as I see it now as there is really nothing to make this storm head OTS after it hits NYC.
Well, those are my points for the night. We'll see if what I've been thinking all along will be right in the end, but for now, I need to rest and get ready for another day of model-watching and forecasting tomorrow. I will post my final snowfall map after the 00z GFS comes out tonight, and I may post examples of the 00z NAM 500mb vorticity charts compared to 6z and 18z to better demonstrate my points above regarding this feature of the model. Until then, off to watch the GFS I go...talk to you soon everyone! This is Student Meteorologist Kyle Elliott reporting for the AKStormtracker Forecasting Center.
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