Beginning Descent into Chase Season 2014

[Matt Hunt]

12z GFS backed the moisture down again, and went back to the elongated surface low vs. the split low. I'd rather see a split with a secondary low in western KS. But those 0-3km helicity values, WOW! Up around 800 in western KS. I'd really like to see some moisture begin to return on Tue, but it's not looking very likely. If this system had 2 days to get that Gulf moisture, it would be outrageous. We'll see how it plays out. I'm still planning on chasing.

 

[Chris Wilburn]

12z GFS backed the moisture down again, and went back to the elongated surface low vs. the split low. I'd rather see a split with a secondary low in western KS. But those 0-3km helicity values, WOW! Up around 800 in western KS. I'd really like to see some moisture begin to return on Tue, but it's not looking very likely. If this system had 2 days to get that Gulf moisture, it would be outrageous. We'll see how it plays out. I'm still planning on chasing.

I just don't know if we are going to have enough time for moisture return, like you mentioned. It would be nice to get low 60's with over 2,000 CAPE, because like you mentioned, that wind shear is amazing. There are still several model runs to come; the NAM comes on board Sunday morning at 12z to compare with the GFS. It looks like a front on late Monday into Tuesday is shoving the moisure back down into south TX, before streaming north late on Wednesday. If this plays out, I definitely don't have hopes of moisture returning in time for Wednesday. Thursday continues to plow to the east. I am not too optimistic, but will still play it out and see.

 

[Derek Weston]

Both 12z GFS and ECMWF show good return flow and a nice setup over the (next) weekend after this initial shot Wed/Thur.

 

[Marcus Diaz]

Seems like with each run this setup gets worse and worse. Then a rogue run of the GFS will bring it back again. If there's one thing I've noticed in the past few years is the GFS usually nails the mid range systems, but always can't decide on moisture. Wednesday definitely looks like it could be a classic setup if we get the moisture. Thursday looks like another shot at I-35. What's really turning me off on both days is the amount of CINH the GFS has constantly been advertising. The 700mb temps were also bouncing between breakable cap and just stay home. Guess the NAM is the next deciding factor. But as others said, the following weekend looks more interesting.

 

[Dan Robinson]

I've retreated fully into "I have no idea" mode for these upcoming systems. There is just no run-to-run consistency or agreement, and what little semblance of that there is doesn't look all that great. I'm going to step back from the models for a while and come back Tuesday to see what things look like then.

 

[Brett Roberts]

I've retreated fully into "I have no idea" mode for these upcoming systems. There is just no run-to-run consistency or agreement, and what little semblance of that there is doesn't look all that great. I'm going to step back from the models for a while and come back Tuesday to see what things look like then.

I can sympathize with that. So far this spring, predictability in the 5-10 day range has seemed subjectively to be worse than average for the central US.

For the first system coming up this workweek, I think one thing is relatively clear: moisture quality will be rather poor on Wednesday. Even if the synoptic evolution works out well and lends to great kinematics and daytime initiation along the dryline, LCLs are likely to be problematic for a high-end day. Model agreement on a longwave pattern that necessarily limits moisture quality (high-amplitude upper trough over the Northeast, locking in a surface ridge that extends down into the Gulf) is high. However, in the best-case scenario, great supercells and a rogue tornado or two could certainly be possible.

It's beyond this first system that I fully agree with Dan. Potential for something more significant, at least in terms of moisture quality, is evident around next weekend (4/26-4/28). However, there have been wild run-to-run inconsistencies, and it's still possible that the midweek system amplifies so much over the east coast that it blocks the next trough from making full progress into the Plains (at least, initially). It's hard not to get one's hopes up, since this is the worst season-to-date I've seen since I started chasing, but that end-of-month potential looks pretty shaky to me at this point.

 

[Paul Knightley]

Indications that from late next weekend into the following week severe potential across the southern and central USA may increase quite a bit. Ensemble output has been indicating this for a few days now, as have some monthly products.

 

[Matt Hunt]

SPC seems pretty optimistic about Wednesday:

THERE IS GROWING CONFIDENCE THAT ROBUST CONVECTION WILL
DEVELOP DURING THE DAY4 PERIOD ACROSS THE CNTRL/SRN HIGH PLAINS.
LEE TROUGH WILL BE WELL ESTABLISHED BY TUESDAY ACROSS THE HIGH
PLAINS AND A NARROW CORRIDOR OF BOUNDARY LAYER MOISTURE SHOULD
ADVANCE NWD ACROSS WEST TX INTO NEB. THERE IS REASON TO BELIEVE
NEAR 60F SFC DEW POINTS WILL RESIDE JUST EAST OF THE DRYLINE BY PEAK
HEATING AND SBCAPE ON THE ORDER OF 1500-2000 J/KG APPEARS POSSIBLE
ALONG WRN FRINGE OF THICKER LOW CLOUDS WITHIN RETURN FLOW. WITH
40-50KT 500MB SWLY FLOW EXPECTED TO OVERSPREAD THE
DRYLINE...ENVIRONMENTAL SHEAR WILL SUPPORT ORGANIZED ROTATING
UPDRAFTS. WILL MAINTAIN 30 PERCENT SEVERE PROBS FOR EXPECTED
SUPERCELL DEVELOPMENT.

 

[Marcus Diaz]

There's no question about it. The mid-week setup looks pretty poor and unlikely. But there's also no denying that next weekend has the potential to be huge if the GFS keeps its look till then. Of course, I think we say this everytime something comes within a week from happening, only to have it not happen.

 

[Andrew Stoller]

This weekend looks OK; now that the ECMWF is in range, it looks better. The GFS still has the trough cutting off into a closed low with unidirectional flow parallel to the dryline but the EC has a more classic looking trough and, most of all, the EC is slower, so maybe a Sat. and Sun. event. Chaser convergence out the a$!

 

[Michael Riedl]

Last Nights 0z GFS was pretty impressive. 12z GFS is naturally different.

 

[Jacob Ferden]

Well, the GFS had shown a volatile setup for next Sunday...naturally, it disappeared. Instead, it has snow in Nebraska. http://www.twisterdata.com/index.php?prog=forecast&model=GFS&grid=3&model_yyyy=2014&model_mm=04&model_dd=21&model_init_hh=00&fhour=168&parameter=SNOWIN&level=SURFACE&unit=none&maximize=n&mode=singlemap&sounding=n&output=image&view=large&archive=false

Is it May yet?

 

[chrisbray]

Each run of the GFS grows more depressing, not just for this week's setup, but for everything in the near term.

 

[Zack Hargrove]

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.

 

[Logan Karsten]

I agree with Zack. The GFS is being very sloppy right now with next weekend's system, moving placement and features. At this range is where i tend to trust the ECMWF more than any other model.