Upcoming Chase Season: 2017 Edition

[chrisbray]

Looks like winter decided to show up now that it's March.

 

[Jeff Duda]

Taking a look ahead - not looking great for a widespread organized severe event for at least the next 7-10 days. I had to go well out into fantasy land in the ensembles (GEFS, Canadian, ECMWF) to find big troughs or shortwaves coming across the Plains. The pattern coming up looks to favor cooler and drier weather with northwest flow across the central US and and eastern US trough. However, CPC temperature outlooks suggest above average temperatures will be maintained across much of the US, so go figure there. Either way, it appears a return to more "normal" early-mid March weather is on the way and severe weather will be pretty much absent over the next 7-10+ days.

We're only just getting started.

 

[Brandon Centeno]

Taking a look ahead - not looking great for a widespread organized severe event for at least the next 7-10 days. I had to go well out into fantasy land in the ensembles (GEFS, Canadian, ECMWF) to find big troughs or shortwaves coming across the Plains. The pattern coming up looks to favor cooler and drier weather with northwest flow across the central US and and eastern US trough. However, CPC temperature outlooks suggest above average temperatures will be maintained across much of the US, so go figure there. Either way, it appears a return to more "normal" early-mid March weather is on the way and severe weather will be pretty much absent over the next 7-10+ days.

We're only just getting started.

I would anticipate the CPC charts to reflect more of what we expect updates today.

As Jeff mentioned organized severe seems really unlikely in the next 14 days or so. However, GEFS AAM forecasts indicate a return to a more favorable phase space for organized severe weather after day 14 or so. Would keep an eye out on late a March and early April as a result.

 

[Brandon Centeno]

For anyone curious on why the above chart was posted, or why they should care, refer to: https://ams.confex.com/ams/28SLS/re...72?entry_password=631903&uniqueid=Paper301564

Seems to be worthy of more research.

 

[Brandon Centeno]

I would anticipate the CPC charts to reflect more of what we expect updates today.

As Jeff mentioned organized severe seems really unlikely in the next 14 days or so. However, GEFS AAM forecasts indicate a return to a more favorable phase space for organized severe weather after day 14 or so. Would keep an eye out on late a March and early April as a result. View attachment 15323

Corresponding to this expected/forecast drop in AAM will be a breakdown of the NPJ, and subsequent western US troughing. GFS ensemble is meh, but EPS much more encouraging: west troughing, no significant east coast trough (in a mean sense). Easily the most encouraging sequence yet, but we'll see how it scales down as we approach event time. Given this is outside of 240 hour window, and EPS on pivotal only goes out to 240, I will not post weatherbell graphics. The EPS shows mean troughing in the west, however.

 

[Warren Faidley]

I don't foresee any major changes in the overall pattern we are currently stuck in. Drought-like conditions in the western part of TA and the late April into May dryline initiating in the Vernon, Elk City, DDC to GLD regions with some upsloping possibilities in Eastern Colorado in early to mid June. The OKC region will once again have an elevated risk as the storms move off the dryline to the west and mature just west of 1-35. There will be isolated events further west as always, but capping will ruin the party more than holding back the show for isolated events.

 

[Jared Orr]

While I won't pretend to have the technical knowledge that some of you have...I am definitely encouraged to see the GFS and CFS deterministic models picking up on an active weather pattern for late March, early April. ECMWF also hints at a large trough ejecting into the CONUS late next week. Climate Prediction Center agrees with above-average precip for the same time frame.

 

[Jared Orr]

However, GEFS AAM forecasts indicate a return to a more favorable phase space for organized severe weather after day 14 or so. Would keep an eye out on late a March and early April as a result. View attachment 15323

Nice job Brandon for picking up on this a week ago.

 

[Paul Knightley]

ECMWF ensembles also show a pattern shift which looks to be more conducive to severe weather in the upcoming couple of weeks. Several long-wave troughs developing over the western CONUS and then shifting eastwards.

 

[Bruce Torrens]

Southeast TX into LA showing impressive dews aoa 70F March 30 thru early am March 31 with a shortwave coming in to TX. Too far out to pinpoint details on locations, but I'd but my money on Arkansas - the tip of the moist axis - for strong tornadoes if that verifies.

 

[James Gustina]

Looks like the upcoming trough may be working with some timing issues that haven't fully been resolved yet, but the flow pattern in general is encouraging at least. How long it takes the cold front to wash out before moisture begins coming north again later this week might be the decider as to whether or not we get something out of this.

 

[Jeff Duda]

CIPS GEFS analog forecasts point towards a rather high probability of severe weather occurring early to mid next week



CIPS analog forecasts also suggest non-negligible probs across TX and OK going into the first few days of April, but the probabilties max out around 40%-50%.

For those curious, the website is here: http://www.eas.slu.edu/CIPS/ANALOG/extended.php. Just click on a subdomain and go to the last column.

Finally, the latest ERTAF forecast issued Sunday calls for "above average" tornado occurrence for the next two weeks. Obviously these are broad-scale generalizations. Specifics have yet to come into play, but I'm currently eying a trough coming into the southern plains on Sunday. It has been rather consistent over the last few days on the GFS. However, there is quite a bit of uncertainty in the ensemble forecasts.

 

[chrisbray]

Looking like moisture could be an issue for next week. If so, it could be a while before the next decent setup.

 

[Andy Wehrle]

Sometime in the April 9-11 range has my attention. GFS has been pretty consistent with a large trough/surface system around that timeframe for a few runs now, and it looks like it should have less moisture issues for the Plains/Midwest then we've seen so far.

Now watch it disappear on the next run.

 

[Brett Roberts]

After the past week, concern for drought to mitigate severe weather opportunities later this spring in the southern Plains is dwindling fast. Particularly across most of the southern High Plains (at least from the TX Panhandle northward), these are very impressive totals for March.

I would speculate that so long as we see April rainfall that's at least within the normal range, we should be well on our way to a third straight year of quality evapotranspiration west of I-35. This should be great news for all chasers, and particularly chasecationers focused on the late season. Unless the large scale pattern is particularly awful throughout the late season, I'd expect a tendency for weakly forced, mesoscale setups to overperform under these conditions (similar to the late May periods in 2015 and 2016).

Hard to believe, after we could hardly buy a setup west of 98°W with <20 F T-Td spreads from 2011-2014.