Beginning Descent into Chase Season 2014

[Chris Wilburn]

I would be careful taking the GFS for gospel next weekend. The solution looks fishy, and the model cannot find any consistency from run to run. Meanwhile, the Euro (with some support from the UKMET) is still painting quite a serious picture. Serious warm sector with tons of energy. Verbatim, the Euro would spell a multi-day outbreak of some sort (this is NOT a forecast, just speaking of the latest Euro run as is). Also, if you look at a number of the GFS ensemble members, the operational version looks rather funky. A number of the GEFS members show a very potent setup, as well. I'm not taking the operational GFS very seriously for this one at this time.

I totally agree with you Zack. The GFS does look rather bad, but the ECMWF looks amazing for next Saturday and Sunday; possibly into Monday for eastern AR if things play out right, and the terrain over there isn't bad at all. The trough does arrive somewhat late in the day on Saturday, but still showing a potential impressive day for western KS and down through the OK/TX panhandle. Sunday it's' showing a central OK type setup. Both days are showing plenty of moisture and instability. I'm not taking the GFS too seriously either, and trust the ECMWF. Of course it's still 5 days out, but there are major differences between the GFS and ECMWF, with the ECMWF looking MUCH better. I'm glad you mentioned the UKMET is supporting the ECMWF solution some as well. I don't look much at the UKMET so hearing your analysis on this is refreshing.

 

[chrisbray]

Alright so....Realizing there could be further outbreak today in Mississippi and Alabama, and possible in the Carolinas/Virginia tomorrow. But looking ahead into the next chase-able scenario. Obviously this week/weekend will be quiet as the giant low departs. NEXT week could see some action Tuesday - Thursday? Looks to be more zonal flow at first, but amplifying somewhat towards the end of the week. Moisture return should be decent once the current system departs. Possibly some shortwave impulses could trigger something? GFS has been consistent for a while in developing a surface low over the plains that lingers for a while.

 

[Derek Weston]

Alright so....Realizing there could be further outbreak today in Mississippi and Alabama, and possible in the Carolinas/Virginia tomorrow. But looking ahead into the next chase-able scenario. Obviously this week/weekend will be quiet as the giant low departs. NEXT week could see some action Tuesday - Thursday? Looks to be more zonal flow at first, but amplifying somewhat towards the end of the week. Moisture return should be decent once the current system departs. Possibly some shortwave impulses could trigger something? GFS has been consistent for a while in developing a surface low over the plains that lingers for a while.

I think it looks rather active, myself. Not necessarily giant days, but some fun stuff for sure. That far out I just look for moisture return and decent upper level support, both which the GFS says we'll have. Be interesting to see how this unfolds.

 

[Mark Blue]

For all intents and purposes, and based on the current (0Z) ECMWF 500 MB wind speed chart, it appears that there is another trough on deck and second one in the hole behind this current system. As you advance through the frames, the mid level flow and embedded low gets shunted to the north in what appears to be a shortwave pattern for the mid/next week timeframe. Thereafter (out to 240 hours) it flattens out and becomes more zonal in nature. The central and northern plains will be under SW flow aloft, so hopefully the moisture will return after being swept clean out of here by the cold front this week. I hope the faster flow aloft doesn't get confined too far north this early, as that brings back memories of 2009 for me at least.

 

[Jeff Duda]

I see a pretty quiet pattern for at least another 7 days or so. Frankly I'm surprised and amazed that this current cyclone over the upper Midwest and the disturbance forecast to scream straight south out of Canada and down the Front Range to the Mexico border later this week doesn't completely sweep the Gulf clean of moisture. Although it does look like there will be a surface high parked over the central Gulf until at least next Monday. Yet somehow the GFS has a bunch of moisture (in some cases deep) building along a stationary front that will sit draped across the high plans through Ohio Valley later this week and into next week. I suppose that could be the result of moisture transport from the ground due to all the rain that has fallen across the Mississippi River valley over the weekend. You have to go past hour 200 to find deep moisture coming off the Gulf in the 12Z GFS. BTW, the 12Z GFS sets up a heat dome over the SGP region early next week. Looks like the first 100s of the season will occur then.

About the only encouraging sign I see that the spring severe season isn't finished south of I-70ish is the forecast of a mean western US trough in the NAEFS/GEFS and ECMWF ensembles in the 168-300 hour time frame. Although depending on which core you look at, the mean trough doesn't stick around for a long time.

I can say I hope the 312 hr 00Z 30km FIM8 forecast verifies. But when you have to go that far out to get a good system and it's late April...

 

[James Gustina]

Looking like I'll be heading back east without a tornado next week. That trough sweeping in out of the Pacific interests me to a point, but I'm going to be so spent by finals week that if it's not looking like a surefire tornado day as it comes in then I might not chase. I love structure and all, but I'm getting really sick of all these high-based, anemic supercell days.

This recent southeastern outbreak aside, it looks like we'll continue the same pattern of horrible chase days. I'm hoping this pattern eventually develops into a decent flow regime for the upper-Midwest come late May/early June a la 2010, but I'm not overly enthusiastic about that. I've never had much success in Illinois/Indiana/Iowa and I doubt after 6 years of futility I'll actually get a nice looking tornado east of the Mississippi.

 

[chrisbray]

Quite the pessimists. 18z GFS run doesn't look half bad next week Wednesday/Thursday (and the 500mb pattern not too shabby afterwards). Currently showing an impulse moving out of southwest flow on Wednesday May 7, and continues to move disturbances out of the southwest through that weekend. Here's hoping!

 

[Mike DeLange]

Quite the pessimists. 18z GFS run doesn't look half bad next week Wednesday/Thursday (and the 500mb pattern not too shabby afterwards). Currently showing an impulse moving out of southwest flow on Wednesday May 7, and continues to move disturbances out of the southwest through that weekend. Here's hoping!

Agree with the initial assessment, with the caveat GFS long range can be, of course, fickle to say the very least. That being said, GFS has been somewhat consistent for activity around the 8th/9th timeframe

 

[Paul Knightley]

ECMWF Ensembles suggest the development of a western US trough by mid-week next week, and then only slowly progressing eastwards. I would suggest an up-tick again in severe potential next week. GFS ensembles depict a reasonably similar story.

 

[James Gustina]

Middle of the week next week does look interesting. Really good moisture transport a few days before the event and not a cold front in sight for a change. Doesn't look like a slam dunk but it falls on my last day of exams and it'd be an easy drive west after my final.

 

[Mark Blue]

It seems like the trend has reversed from what I looked at yesterday, talk about a 180! The Euro, Navy, and Canadian models I looked at today make next Wednesday and especially Thursday really worth keeping an eye on. The energy coming out into the southern and central plains ramps up on Thursday, and the moisture isn't looking too shabby either, with maybe mid 60s in the warm sector.

 

[Logan Karsten]

Meh.... at this point in the season, I am ready to start seeing near 70 dews in the plains. Yes, there is a trough in the long-ragne GFS, but for right now, the moisture by the time it makes it to the plains is modest at best, and this is with a model that tends to have a moist bias in the medium-long range. This week is really going to work hard to clear the gulf out of moisture, which is going to have an impact on any chance for severe weather through the middle of next week. Now, if that trough were to slow down and allow moisture to return for a day more or so, then things might start looking up.

 

[chrisbray]

I dunno....from the looks of the models....you have the gulf opening back up starting early saturday, which gives you 4 days of return flow on wednesday, and 5 days on Thursday. Upper 60s dews seems reasonable. If it was 60f, that would be modest, but upper 60s is usually good enough.

 

[James Gustina]

It seems like the trend has reversed from what I looked at yesterday, talk about a 180! The Euro, Navy, and Canadian models I looked at today make next Wednesday and especially Thursday really worth keeping an eye on. The energy coming out into the southern and central plains ramps up on Thursday, and the moisture isn't looking too shabby either, with maybe mid 60s in the warm sector.

The possibility of surface-based storms alone makes this noteworthy. It's still a week out but that is encouraging that it's been showing decent moisture making it well into the Plains.

 

[Dan Robinson]

"When it's May, you chase" - Tim Marshall. Moisture and more than 30kts of midlevel flow in May = chaseable.