Tuesday, October 1, 2013

October 4-6 Potential Winter Storm

There is potential for a winter storm to hit the Plains during the timeframe of October 4-6.

The energy that will make up this storm system is currently in the Gulf of Alaska, shown as a dip in the jet stream in those waters. It is anticipated that the energy will follow the jet stream and shift southeast into the Pacific Northwest. Un-needed rainfall will accompany this storm system as it enters the Pacific Northwest, along with some heavy snowfall in the mountainous regions of the northwest Plains and Pacific Northwest.

By the time the storm system enters the Central Plains, it will have bottomed out to the Rockies, as the jet stream is pictured to buckle as it carries the storm system east and eventually north. The flow out ahead of the system pictures where the storm is expected to move towards, with a northeast track most likely.

As this storm moves northeast, it now appears that a winter storm, possibly a blizzard, may hit portions of the Plains in the next 5 days. Latest model forecasts encourage a very strong system to develop, with an intense snow band to the northwest of the storm system. The GFS snowfall forecast is shown below, with the NAM forecast immediately below it.

GFS snowfall forecast through Hour 108
NAM snowfall forecast through Hour 84
Models tend to agree that if this is a big snow event, it will hit the Dakotas the worst. The NAM and GFS agree that amounts may approach or even surpass the one foot mark. Based on the composition of the storm system, I wouldn't be surprised to see scattered reports of amounts over 12'', with this being a very strong and well-set-up storm system. What is worth mentioning that the ECMWF model is not on board with this being a big snow producer. The latest maps I have seen have significant mountain snows in the Rockies, but nothing in the Dakotas from the ECMWF. As of right now, I'm naturally skeptical of such a big storm, but if it does happen, this would have significant implications on the winter pattern this year.

Andrew

6 comments:

WeatherMan11 said...

what are the chances of iowa getting snow

Anonymous said...

Maybe talk about the potential tornado outbreak ahead of the cold front?

Anonymous said...

THIS EARLY? What the heck??????? How is that possible?

Anonymous said...

Ok, Iowa will not get any snow, not even a dusting. That is the way it will be. I have spoken & now written this, so that is the way it will be. No snow for Iowa ever! I will take some rain now and then, but not buckets loads at a time! I'm serious! Sorry to be such a wet blanket, but I cant help it.
Thank you Andrew for all your hard work, I really do appreciate all you do in keeping us informed!
But snow...no.
bree

Frank-o said...

........"this would have significant implications on the winter pattern this year"......
.....Ahhhhhhh Yes....This is exactly the pattern I do not want to see set up this fall and winter. As the jet tries to dive south it hits the ridge and storms are forced to the Tenn/Ohio valley area and they just kiss the West facing slopes of the App. Mts. and leaves us here on the East facing slopes with.......nothing........There is hope tho....if we can get a strong N-NAO...........

Anonymous said...

Thank you Bree for speaking and writing your truths. It is refreshing to know that when you speak something, that is the way it will be. You are a wet blanket. But wet with rain..not snow, right?