Dec 18-22 Potential Winter Wx Event

[Brandon Sullivan]

Models have been consistent lately in advertising a significant weather maker moving into the midwest early next week. The setup is very similar to the major winter storm only weeks ago. This system however, will initially deal with strong dynamics, and COPIUS moisture, as well as much higher than average temps.. Therefore, we could see a fairly wide area of thunderstorms. possibly getting strong... During the period... Not seeing the cold push to be as extreme as in past model runs, but will have to watch for a change over to snow for accumulations! Dont want to get my neck chopped off so wont get too specific or go in to much detail.. But will have to watch closely!


Brandon-KC9ILN

 

[Jeff Snyder]

As a note, that, as we did with the past system, winter precipitation can classify as a "significant precipitation event" and, thus, can be discussed in a FCST and NOW thread in the Chase Forecast forum. Also, for future reference:

(9) Chase topics spanning multiple or ambiguous dates are prohibited, such as "FCST: This Weekend". Map Room is chronologically organized and is dependent on exact dates. Pick the most representative calendar date and post your message there. Commit to a date, and if it changes you can always move to another thread or start a new one.

I normally use the PM system to address issues such as this, but I figure we may have several more winter storms through the next few months, so I'll mention this to all.

This topic will pertain to the WINTER WEATHER aspect of the event. If a convective storm (i.e. deep moist convection that we typically chase) threat develops with this system, then a new FCST thread should be opened to address that threat. We typically prefer to use a thread in Weather and Chasing for events that are a good deal into the future (e.g. >5-7 days), since the forecast error potential is great. For example, the "pattern change coming?"-type of threads are allowed in the W&C forum, since date and event specifics cannot be addressed with much confidence a week or more in advance. In this particular case, we'll keep this discussion in this FCST thread since most models indicate a strong, high-amplitude upper-level trough and low-level cold front making their way into the central US next week (implying the potential for a significant surface cyclone).

The date chosen for the thread is based on the 12z GFS run from this morning, which shows a strong ~985mb low over the Great Lakes by 21/12z, with the threat for heavy snow from the central plains to the western Great Lakes.

 

[Jeff Snyder]

Well, I had a change-of-heart. I think the system being addressed in this thread is too far into the future that it really is a "wishcast" situation at this point (for those looking forward to winter weather). This thread can be moved into the Chase Forecast forum in a few days (by the end of the week) if it appears more likely that such a cyclone indeed will develop across the central US. There tends to be quite a bit of 'waffling' this far in advance, so informal discussion that may result is more fitting for W&C than a FCST thread.

 

[Brandon Sullivan]

I agree with the decision. It is still way out. Models cant decide on a track or southern desent of cold air intrusion. Do agree that it would be best to wait. Thank you sir.

Brandon-KC9ILN

 

[MatthewCarman]

Is this the system coming off the west coast you are talking about?

 

[Dustin Wilcox]

This system definitely holds some potential to give someone a better chance at a white Christmas, the ECMWF is favoring a more southern track with the system favoring some winter precip for the TX panhandle region however the GFS especially today’s 12Z favors a quite significant winter storm over the NE, KS and IA areas. Way to many discrepancies in the models and also to much time for things to change to get too excited but definitely worth monitoring model trends.

 

[Brandon Sullivan]

notice models are trending further north with heavy axis of precip and further soutward extent of cold air push. Yes, I agree. It definitely has potential.

 

[aaron.burkham]

i was in decatur for the last one, but i am waiting to see how fast this system will be moving.

 

[Brandon Sullivan]

just for the note the latest GFS is further southeast again! and colder. The trend looks to be, the low is taken further south before being cutoff and ejected into the plains

 

[Rocky Rascovich]

Lucky me!!! I'm heading up to the MSP area to get my mother in law and family for Christmas back here in Okla. on Wednesday the 20th I may leave a day early and enjoy the storm. I'll be following this close!

Rocky&family

 

[Rocky Rascovich]

What happened!!

Looking at the 12Z GFS run, this model is up to its dastardly deeds once again and shoves all the precip. south and east of the OUN forecast area.
Hard to believe with so many previous runs being so consistent with a major bout of VERY MUCH needed rain here in cntrl Okla.

In addition, the system slated to move across the mid section of the country has all but vanished... I'm thinking this has to be an abberation of the the recent runs on the GFS..... hopefully.

Rocky&family

 

[rdale]

Look at the amount of spread in the ensemble GFS - it amazes me that people even think to get specific on placement when there is so much uncertainty... It is an absolute waste of time to make long range forecasts if you only look at one slice of the GFS.

http://www.emc.ncep.noaa.gov/gmb/ens/targ/mslpensmnP2.2006121412.html

 

[Brandon Sullivan]

models look somewhat similar with latest run. Slower seems to be the trend. With the GFS still all over the place. ECMWF has stayed somewhat stable. But slower and further southa and weaker is the trend

 

[Rocky Rascovich]

Can't live and die by the GFS!

I appreciate rdale's shock treatment on the reliance of one model. I sometimes get to wound up looking at that model and with my time constraints on our family computer.. sometimes I just don't have the time to dig into the complexities of deciphering the rest of the data.

Still, analyzing the ensemble data from 0Z thismorning, the Canadian, UKMET, ... and ooooh God, the GFS too... I'm guardedly optimistic of our rain chances next week here in Okla. and even a small window of opportunity of severe weather further east in Ark for the 20th. I just hope that the upper low doesn't move too much further north than expected or we'll get dry slotted here in cntrl Okla. Time will tell.

Rocky&family

 

[Sean McMullen]

rdale you can't talk to Rocky like that, what's wrong with you?

Rocky I'm with you man,according to this mornings runs GFS and ECWFM are in pretty good agreement with the placement of the closed low and it looks like we can finally get some winter wx up here in NE on Wednesday and Thursday.