Saturday, November 16, 2013

November 24-28 Winter Storm

It is likely that there will be a winter storm in the days prior to Thanksgiving.

This is a forecast from the GFS Ensembles out to the Hour 60 timeframe. While all of the colors and lines may seem a little overwhelming, we're only going to focus our attention on East Asia, which is under the deep blue swath in the top left part of the left panel. Another correlation that has been proved effective is how weather in East Asia can be reciprocated in North America 6-10 days after the weather anomaly in East Asia. This includes the presence of storm systems or high pressure in East Asia. The November 18 forecast from both the GFS Ensembles and ECMWF model indicates that a deep negative height anomaly swath will slide down over Japan. If we extrapolate November 18th six to ten days out, we come up with a potential cold weather and storm system time frame of November 24 to 28. This narrows down the timeframe previously set out by the Bering Sea correlation, and if we match up the two timeframes (November 24-28 for the East Asian connection and November 25-29 for the Bering Sea connection), we come up with a November 24-29 potential timeframe for a storm, which can be isolated into the November 25-28 period, which is shown by both connections. Based on these two connections coming up with a common timeframe for a potential US storm system, confidence is quickly rising that this event will happen.

The question now is, where will this storm system go?

European ensemble projections of the North Atlantic Oscillation (top) and the Arctic Oscillation (bottom) are negative for the timeframe of this storm system. This suggests that the storm system should be sucked into the subtropical jet stream, and ought to go along the South US. The Arctic Oscillation going negative for this system's timeframe tells me that the chance of cold air for the North and Northeast US will be on the rise, and this would theoretically aid in the potential for snow in those regions.

The ECMWF projection for the Pacific-North American index has been consistent with the index rising for the timeframe of this storm system. This would allow ridging to form along the West Coast, and help out the chances for this storm system going to the Midwest and Great Lakes. I'm hesitant to believe thoughts that the positive PNA will automatically force this system to head to those regions, as the negative NAO, if it grabs ahold of this system, will wield a good deal of influence on the track, so long as the system does get into the subtropical jet stream. Model solutions have been variable, but here's my early projection for this scenario.

Andrew

8 comments:

unknown said...

Thank you for all the information! I cant wait to see what happens, but I really think you should focus on the upcoming severe weather event. There is a moderate risk in effect and you have yet to mention that!

Andrew said...

Read yesterday's post for that info.

Anonymous said...

I already read that post, but I was wondering if you were going to make another one with the moderate risk.

Anonymous said...

no you have not said that in your forecast yesterday. i agree with the first comment. oh wait i forgot you only made a few mistakes in yesterdays forecast.

1. why is western new york state in the risk?
2.best threat is way to far east.
3.the storm forming area is awful.
4. how long did it take for you to make that map.
5. and it just generally is not that good. (no offense)

Andrew said...

Anonymous at 8:44: Then just say you think the storm forming area is too far east and leave it at that. There is no need for all of this "awful" stuff and telling me it's not good. If you don't like it, move on. Don't comment about how you don't like it the way you did.

Anonymous said...

I am so Thankful it is not coming near Iowa!! I have a huge Thanksgiving dinner & do not want snow! Now for Christmas...I will put my order in now, I only want a dusting..enough to make it pretty!
Thank you so much Andrew! You keep us all in the know & for that we love you!
bree
P.S. Remember...just a dusting!

Shawn said...

That potential winter storm is looking better all the time! I would like to know which track is best for heavy snow in the state of Missouri because whichever track that is, I hope that is the one that occurs! :)

Thank you for the update on the November 24-28 Winter Storm! :)

jhon junior said...

I can't wait for snowfall.