Start of the fall "season"?

[Jim Bishop]

I'm expecting a lot more troughing over the western/northwestern U.S. into the northern Rockies and northern Plains in late Sept into most of October. This, I believe, will be the response driven by the recent rapid cooling (over the last few weeks) of the northeastern Pacific sea surface temperatures, among other factors. Downstream ridging over parts of the eastern U.S. should be the natural response to this troughing. Medium range models have been trending toward this pattern for a few days now in the 8-15 day period, which increases my confidence in the overall idea. While this does not guarantee severe weather stups in the plains, it's certainly a good start.

Thus, I'm cautiously optimistic about this year's October upper air pattern for potential chase setups in the Plains. Other, more regional and localized factors such as moisture, wind shear and forcing will have to work themselves out. I'm crossing my fingers.

 

[Andy Wehrle]

We are due. I can't remember a warm season with a UA pattern that was so persistently hostile to severe convection for so long, over the majority of the Plains and Midwest.

Among the opportunities chasers had that looked good, or were expected to be good a few days out, something went awry with each and every one.

Anyone who bagged tubes this year should be applauded for their dedication and perseverance.

 

[Kevin Walters]

Mid September through mid November has produced significant tornadic events in Iowa in the past. Obviously the odds are against a big outbreak, but it is possible. In any case the pattern looks like it will become more interesting.

 

[Bob Hartig]

Last I looked, which was last night, both the GFS and ECMWF were showing a trough moving into the central US around Sunday. Moisture wasn't very impressive, but just seeing a break in the ridge is encouraging.

 

[Jim Bishop]

Last I looked, which was last night, both the GFS and ECMWF were showing a trough moving into the central US around Sunday. Moisture wasn't very impressive, but just seeing a break in the ridge is encouraging.

The operational models have been performing absolutely awful recently beyond day 7. I was refering to the GFS and European Ensembles and my personal interpretations of the two. But yes the trough will setup first over the north central U.S./northern Rockies in 6-10 days and then (hopefully) retrograde with time. We'll see.

 

[Brendon Lindsey]

Im keeping my eyes on monday for a possible play. 12z 108 hrs out had some interesting features. If this model verifies and adds some more shear I would be playing it most definately. Hopefully there would be discreet storms at the beginning before a squall line would form.

 

[Mike Hollingshead]

http://weather.cod.edu/loops/gfsUS.500vort.html

A sort of funny loop for next week's low. Hope those under the current one aren't sick of clouds just yet! Probably be more our turn this go around. Hoping Monday pans out for something around Iowa.

 

[JeffGonzales]

Man it's hard for me to post in a thread with a big, ugly, orange cow at the top. But I will anyway.

HAHA I second that. Wreck'em Tech

 

[Ryanne Jobsian]

I am pretty much convinced the year is over for me. I really cannot complain as it has been very active from April to the very end of August. Stalled out troughs have been my friends this year. As soon as August was over, fall seemed to arrive. An area of low pressure (non-tropical) formed off the coast and just sat there more or less, blocked by a ridge of high pressure in New England. That was very depressing indeed. A solid week of chasing and then suddenly, cold, rainy and windy. Thanks mother nature for just throwing me into fall..which I was not ready for!

For days we have had this pesky high pressure which is moving off the coast. A trough is supposed to form but nothing conducive to storms or anything much in the way of precip. I love how the NWS forecaster put it.. "THIS HIGH HAS
ALLOWED THE FORECAST AREA TO ENJOY ANOTHER DRY, PARTLY SNY
DAY..." Yeah, I am ecstatic..

 

[Adam Penney]

Check out tonights run of the 00Z GFS. Gigantic trough plowing into the central plains Sept 30th-Oct 2nd.

I have been out of town the past few days, so I have no idea if this is the first run to show such a significant trough. Will be watching for consitency now in forthcoming model runs..

 

[Jim Bishop]

Well the models are finally catching on to my idea of more troughing out west into the Rockies late Sep and early Oct. This is the first GFS Operational run that's shown that, but the ensembles have been showing this for days (particularly the European Ensembles).

From what I'm seeing there should be a couple chase setups mid to late next week across the southern to central Plains. And there should be more as we head into mid October.

 

[Adam Lucio]

The GFS began to show sings of troughiness for that perdiod over a week ago. I posted something about it but got the usual "Your a moron for looking that far out" type comments. Nice to see it coming back though as it did dissapear for awhile.

Something to monitor for sure! Perhaps the global shift has begun and we can see a string of west coast troughs for some fall action.

 

[Jason Foster]

Like Ryan and the other east coasters...this year was very active locally. September and October bring a good potential for storm and tornado activity here in the mid-Atlantic. The Univ. of MD F3 happened in Semptember and the tornado that started it all (the tornado that hit my house) struck on October 18th.

However, in actuality I'm preparing for the Winter Season already. Having just been to the southern Hemisphere and playing in the snow there, I'm ready early. I'm certainly going to do my best to drive out to see snow wherever it falls (in the NE or eastern Midwest). Luckily I already bought all my winter gear, now I would like to upgrade the camera gear (oh and get snow tires for the Subie).

 

[cdcollura]

Good day all,

The trough next week (starting about 120+ hours) out looks very impressive, something not seen in a very long time.

This looks more impressive than what we saw in May / June this year ... But this time, there are no time constraints, so if I need to get out there, I can - and I will (if this verifys)!

Anyone remember Sept 16 2006 (SD)? How 'bout October 9, 2001 (OK)?

But keep in mind this is 2009, and the GFS has been showing "troughs" like that 5+ days out, only to be replaced with a "ridge" less than 3 days out. Looking (and hoping) for "consistancy".

 

[Jim Bishop]

The GFS began to show sings of troughiness for that perdiod over a week ago. I posted something about it but got the usual "Your a moron for looking that far out" type comments. Nice to see it coming back though as it did dissapear for awhile.

Something to monitor for sure! Perhaps the global shift has begun and we can see a string of west coast troughs for some fall action.

You received criticism for your post because you were making a forecast, or at least a wish cast, based soly on one run of the GFS Operational model looking out about 15 days! Did you check to see if there was any consistency? There wasn't. In fact over the last week the GFS has displayed incredible run to run inconsistecies. It's usually not wise to trust the GFS Operational model beyond day 10...and this time of the year it's an extra fail to do so.

Out of curiosity, I went back and looked at the 12z Sept 14 GFS run (over one week ago), and for the Sept 29/30 timeframe it was forecasting a ridge over the West and a trough over the Plains and Great Lakes. That is not likely to verify at this point based on the current ensembles. So I'm not sure what one run you saw, but the point is anyone can look at one fantasy GFS run and report it online, but it does no good without support from other models or teleconnections, etc.