Friday, October 24, 2014

November 2-6 Potential Cold, Stormy Weather

I'm monitoring the threat for the season's first wintry blast of Arctic air in the next few weeks.

Tropical Tidbits
The image above shows the ECMWF model forecast for 500mb geopotential height contours and normalized anomalies, valid on the morning of October 27th. Blues depict areas of troughing, which lead to cold and stormy weather, while reds indicate the presence of ridging high pressure, which permits the formation of warmth and quiet weather. The graphic above shows a pretty strong upper level low dipping south into northern Japan on October 27th. We can observe this storm system pushing due east or a bit east-southeast as it moves in the aforementioned direction, and as it does so, the upper level low is expected to scrape northern Japan, if not actually centering itself over the northern part of the country.

When we apply the Typhoon Rule, which states weather phenomena in Japan is reciprocated in the United States about 6-10 days later, we might expect a pretty sharp cold blast of air in the November 2-6 timeframe.

Tropical Tidbits
For the sake of diversity, we'll analyze the GFS model's 500mb forecast as well, this one valid for the morning of October 28th. The GFS has this strong upper level low displaced a bit south of the ECMWF's location, and obviously slower than how the European model has the low progressing. But the kicker here is how the upper level low is stronger in the GFS forecast as opposed to the ECMWF. If the GFS ends up with the more accurate forecast, it's certainly a possibility that our cold weather in this November 2-6 timeframe may be more severe than currently thought.

To summarize:

- A sharp blast of cold air is expected to hit the United States around a November 2-6 timeframe, potentially with wintry weather.



nancy-Lou said...

I guess that means Canada will be really cold! How about the province of Manitoba? Thank you.

Anonymous said...

Will the cold air be n southern michigan?

Anonymous said...

I don't get it. At the top story , you talk about east being warm next couple of weeks and here you expect cold weather starting next week ?

Andrew said...

nancy-Lou: Manitoba will likely also receive the cold weather, should this forecast verify.

Anonymous at 10:23: If the forecast verifies, yes.

Anonymous at 10:47: This looks to be a few days of cold weather, not really sustained. The worst cold should impact the North US, not the East at this time.

Jim Mol said...

Thanks for the blog, as one who enjoys learning about the weather, though some of this above me, and a former pilot, I find this interesting and informative.
What really puzzles me, esp when you forecast based of Japan's weather, is where it comes from here in the US.
I live in Michigan and you have two period you have forecast wx. NWS forecasts rain/snow Friday and Saturday. OK, it seems to match up with what you say, but as I look at Unisys map I can't figure out where it will come from. A couple of lows in the central plains, a bit of moisture, but nothing I can see that will feed it, yet.
Here is my question: Is there any chart on the web that tracks storms after the fact? Can I log in somewhere and see how the storm developed? I realize you have limited time and am appreciative of what you already do, so I am not asking you for this. Thanks again