Unseasonable Chill To Dominate North-Central Canada To Ohio Valley Sept 18-26th (Includes Video!)

Written by on September 14, 2012 in North and South America, United States of America, Videos with 0 Comments

You’ll be well aware of the first in a series of troughs which will drop out of Canada early next week bringing unusually chilly air for so early so early into the Great Lakes, Midwest and Ohio Valley. The question is how cool will it get and how far south.

From what I’m seeing just now, Monday through Wednesday will see the cool further north extending from the N Plains to Great Lakes but Wednesday towards next weekend, a stronger wave drops down and this could spread the chill much further south.

The models have been persistent and with the tanking of the NAO/AO on the ensembles, everything is pointing to a rather chilly seciond half to September and when all is said and done, the period from the 18-26 could be one to look back on. Snow showers could spread south of the border and across parts of the Lakes, perhaps up over Wisconsin and Minnesota with more widespread snow showers up across Manitoba, Ontario and eventually Quebec. Daytime highs could be held in 40s north of the border with 30s in central and northern Manitoba and Ontario. 40s may even reach just south of the border with 50s more widely across parts of Minnesota, Wisconsin and the UP of Michigan.

Heights Soar Up West Coast

The PNA has heights soar up the west coast and record warmth could go all the way to the arctic circle next week while the opposite occurs further east. Although early in the game still, the AO shifting negative along with the NAO does suggest that really through the remainder of September, one would sway towards a rather cold second half to this month which could elad into the first part of October. With each new trough sweeping down, remember that it is likely to grow chillier with snow chances rising.

Most importantly next week will be the night lows and how cold it gets. I would think that from mid to late next week in particular when a stronger secondary trough drops down with lower thicknesses, we could see frost or a freeze extend all the way to Missouri with widespread low to mid-30s across Iowa, northern Missouri, Ohio, upper 20s for central and north Wisconsin, Michigan and perhaps teens for northern Minnesota and the UP of Michigan.

Recurving W. Pacific Typhoon Will Keep Trough Axis Over Ohio Valley Next Week

While very rare, the infamous 540 rain/snow height line appears to creep down over the northern Lakes with snow flakes expected to fly, the core of this cold will be WEST of the Appalachains next week but into week 2 and renewed troughs swing the axis east. As for next week, the more Ohio Valley centred trough is likely in part due to the further west track of Super Typhoon Sanba in the west Pacific which will take aim at Korea after a hit on the southern Japanese islands.

A recurving west Pacific typhoon which tracks further east and over water rather than scraping Asia would bode better for an East Coast US trough but since it’s further west, the models are seeing this.

The whole theory was first alluded to me by Joe Bastardi who learned this himself back in his years of study. Generally what happens is a recurcing west Pacific typhoon will pump the ridge over NW North America which in turns drops a trough into the central or eastern US depending upon the typhoons recurve position over the W Pacific. This tends to occur 10 days after recurve begins.

Flooding Rain Potential For Eastern Seaboard

Unfortunately with this type of setup and a further west trough position, this always opens the door to tropical moisture flowing up the East Coast and that will be the case throughout next week. Expect heavy showers and thunderstorms to dominate and rain totals over a 3-6 day period of between 2-4, locally 6 inches.

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