Wednesday, October 1, 2014

October 11-15 Potential Winter Storm

It appears the Central and Eastern US may see a wintry storm system push through around an October 11th to 15th timeframe.

Tropical Tidbits
The image above shows the 500mb height anomaly forecast from the GFS model, valid on October 5th. Blues on this graphic indicate negative height anomalies, which typically bring about cold and stormy conditions. Oranges and reds depict warmth and generally tranquil conditions.

On the image above, we see a typhoon pushing north into the nation of Japan on October 5th, appearing to just miss a merge with the trough to the west of the country. This typhoon looks to hit Japan head-on from this forecast image.

This all plays into our winter storm threat using the concept that weather phenomena that occurs in Japan is reciprocated 6-10 days later in North America / after it happens in Japan. For example, this typhoon hitting Japan looks to induce a period of cold and stormy weather in the US 6-10 days after it his Japan, which puts us on track for a storm system in the US around an October 11th-15th time period.

Instant Weather Maps
Model guidance is already showing signs of this storm hitting the United States. This GFS model forecast, made at the same time as the image at the top of this post, shows precipitation on the morning of October 12th, along with 1000-500mb thickness values. A rule of thumb is that values below 540 on the image above indicate where snow (or other wintry precipitation) is possible. The GFS model shows sub-540 values spread across the Midwest and Great Lakes, meaning we could see some wintry precipitation in those areas.

Surface temperatures aren't conducive for snowfall, but I wouldn't be surprised for some parts of the Central and East US to see wintry weather, possibly including snowfall in the coldest area, when this storm threat rolls around during the October 11-15 period.