Central/Western Summer Medium/Long Range Discussions

[icebreaker5221]

Apr 2001 and May 2006 have been showing up a lot in the 8-11 day GFS ensemble analogue composite, and appear to be overall representative of the ECMWF ensemble mean as well.  Interestingly, Pacific SST anomalies look similar right now to both of those years (although probably slightly closer to 2006). 

 

Of course the real question is what will happen beyond 11 days, which is hard to say right now, but lets just say that I wouldn't be surprised (like Ian) if we flipped quickly to a drought. 

[HM]

Interesting that a lot of you guys are throwing out past springs that were at the beginning of a developing El Niño that warm season.

In the case of 2006, the key was the tropical forcing. In Oklahoma, for example, severe activity really went from mediocre to non-existent mid-May as the MJO crossed from the western Pacific (late April/first week of May) into the phase 8-1 octants (most of mid-May).

Currently, we've got a CCKW moving across the Atlantic with the remnant western Pacific "MJO" signal about to cross the central-eastern Pacific. Late April and the beginning of May will likely continue to see weak coherence on the MJO graphics and unfavorable forcing for severe fans. This doesn't mean you can't see severe weather, but it will tend to make the pattern less conducive.

The final warming in the stratosphere should get going at 1hpa around 4/27 and downwell throughout the upper stratosphere thereafter. Once it reaches the middle and lower stratosphere in early to mid May, the NAM will get disturbed and this could possibly get something going in the tropical forcing department in terms of coherence. It will be then that we will watch for the increase in severe weather again, as the wave crosses into the IO-Indonesian Sector.

But if we swirl around in the "El Niño-like" phases and fail to make an appreciable MJO wave, tilting the scale ever so closely to that ENSO state as the ridge freely builds north with summer's arrival...well...

[andyhb]

Those 12z GFS CPC analogs were just about as bad as it gets for the chaser folk going into early May...

[HM]

Those 12z GFS CPC analogs were just about as bad as it gets for the chaser folk going into early May...

 

May 2001 wasn't a dud though. There were plenty of active days with slightly above normal tornadoes in Oklahoma that month. A lot of the other years were in full blown El Niño-mode or on the cusp of a developing one. I suppose we could be on the cusp of one this year, too, but current indications lean "neutral" at the moment.  

 

Interestingly, 2001 and 2006 about 10 days later saw some activity return and also activity just before the analog dates. Perhaps the analogs based on the GFS suggest to watch the final few days of this month (April 2013) and then perhaps mid-May (May 10-20, 2013)? This is believable based on some of the things I've mentioned and NWP.

[Ian]

I'd take a 2001. Decent for chasing at least.

[Thundersnow12]

May 2001 wasn't a dud though. There were plenty of active days with slightly above normal tornadoes in Oklahoma that month. A lot of the other years were in full blown El Niño-mode or on the cusp of a developing one. I suppose we could be on the cusp of one this year, too, but current indications lean "neutral" at the moment.  

 

Interestingly, 2001 and 2006 about 10 days later saw some activity return and also activity just before the analog dates. Perhaps the analogs based on the GFS suggest to watch the final few days of this month (April 2013) and then perhaps mid-May (May 10-20, 2013)? This is believable based on some of the things I've mentioned and NWP.

 

Pretty much the exact days of my chasing trip this year. Leave the 10th and get back on the 19th.

[brettjrob]

From what I know, 2001 was quite average for chasing. Which, at this point, I think we'd all gladly sign off on.

 

On the other hand, 2006 was, hands-down, the worst year of the decade. Made last year and 2009 look kind. Literally nada in May and June.

[andyhb]

May 2001 wasn't a dud though. There were plenty of active days with slightly above normal tornadoes in Oklahoma that month. A lot of the other years were in full blown El Niño-mode or on the cusp of a developing one. I suppose we could be on the cusp of one this year, too, but current indications lean "neutral" at the moment.  

 

Interestingly, 2001 and 2006 about 10 days later saw some activity return and also activity just before the analog dates. Perhaps the analogs based on the GFS suggest to watch the final few days of this month (April 2013) and then perhaps mid-May (May 10-20, 2013)? This is believable based on some of the things I've mentioned and NWP.

 

Yeah, I suppose if you were to replace 2001 with 2002, then it doesn't get a whole lot worse.

[andyhb]

On the other hand, the 8-14 day analog composite is popping some interesting stuff (more specifically, 5/1982, 5/1999 and 5/2007).

 

[OKpowdah]

Since this appears to be a thread to stick everything and anything weather for the most part, well formed snow squall moving through western Oklahoma right now.

 

I can't get over this place haha.

 

[AgeeWx]

I feel a bit foolish asking this but is the snow actually reaching the ground? I'm not seeing reports of snowfall in W OK but by the looks of things everything is along the Arctic front which would lead me to believe the snow is heavy enough to reach the ground.

[OKpowdah]

I feel a bit foolish asking this but is the snow actually reaching the ground? I'm not seeing reports of snowfall in W OK but by the looks of things everything is along the Arctic front which would lead me to believe the snow is heavy enough to reach the ground.

 

There has been light snow reported in NW OK.

[AgeeWx]

There has been light snow reported in NW OK.

 

 

Cheers.

 

It's nice to see other parts of the country dealing with a strange Spring just as we have up here in ND. Although OK has been some combination of snow and severe events for the past few weeks while we're just stuck dealing with NW flow and Clippers.

[Stebo]

I feel a bit foolish asking this but is the snow actually reaching the ground? I'm not seeing reports of snowfall in W OK but by the looks of things everything is along the Arctic front which would lead me to believe the snow is heavy enough to reach the ground.

 

Pampa TX observed light snow earlier this evening

[Stebo]

Since this appears to be a thread to stick everything and anything weather for the most part, well formed snow squall moving through western Oklahoma right now.

 

I can't get over this place haha.

 

law.gif

 

I am unsure but I would have to imagine if it does snow even a trace there tonight, that would probably be a record for the date.

[HM]

Pretty much the exact days of my chasing trip this year. Leave the 10th and get back on the 19th.

During these "incoherent" tropical periods, retrograding 500mb height anomalies is usually favored. If you watch ensemble mean height anomalies out through 5/10, you can see this happening. The problem is: at some point this will probably stop, whether it is from the stratospheric final warming or the MJO or something. My guess is we are safe to assume retrograding through 5/10 but then all bets are off (this will increase the medium range predictability somewhat through 5/10 as well). At some point, we will come back around to a more suitable pattern for Plains' convection after we get beyond this early May hiccup. I hope things work out for you!

I'd take a 2001. Decent for chasing at least.

Sounds good. I know there was an outbreak of tornadoes on 5/20 that year but nothing exceeded EF2 strength. The SPC did, however, issue a PDS tornado watch in Oklahoma-Arkansas, worried about "strong" tornadoes.

From what I know, 2001 was quite average for chasing. Which, at this point, I think we'd all gladly sign off on.

On the other hand, 2006 was, hands-down, the worst year of the decade. Made last year and 2009 look kind. Literally nada in May and June.

I am worried that 2006 has showed up in some of the sensible analogs but, hey, they are analogs. They aren't perfect and certainly can't predict tornadic activity. There are definitely things happening in this early spring that don't resemble recent duds, despite what appears to be a "dud" season in making now.

[brettjrob]

I give up.

 

[OKpowdah]

Yeah this is kind of disastrous.

 

[Ian]

At least youre not on a one week tour group up ahead

[OKpowdah]

At least youre not on a one week tour group up ahead

 

 

 

When are you going?

[Ian]

When are you going?

 

May 18 - Jun 9

[brettjrob]

At least youre not on a one week tour group up ahead

 

No joke. Remarkable how perilous it's been to choose early May in recent times. Honestly, of the past decade, only 2003 and 2007 would've worked out very well for that May 1-10 period. Just can't imagine running a tour service and having to look customers in the eye weeks like this. Then again, so many of them seem relatively content to dink around places like Palo Duro or the Wichitas if all else fails, so maybe we need to get into the biz.

 

Back slightly more on-topic: the 2006 analog is an odd one from a regional perspective, even if the upcoming hemispheric pattern syncs up. Was so relentlessly warm and dry from winter through summer. We were pushing 95 in early March, where we've hardly been able to buy 75 the past couple months, to say nothing of the broadly-improving (rather than worsening) drought. The ENSO tendency over the preceding ~6 months is not all that different, though, unfortunately. With that said, I'm as far from an expert on seasonal forecasting and global oscillations as anyone, so I'll defer to HM any day.

[Ian]

No joke. Remarkable how perilous it's been to choose early May in recent times. Honestly, of the past decade, only 2003 and 2007 would've worked out very well for that May 1-10 period. Just can't imagine running a tour service and having to look customers in the eye weeks like this. Then again, so many of them seem relatively content to dink around places like Palo Duro or the Wichitas if all else fails, so maybe we need to get into the biz.

 

Back slightly more on-topic: the 2006 analog is an odd one from a regional perspective, even if the upcoming hemispheric pattern syncs up. Was so relentlessly warm and dry from winter through summer. We were pushing 95 in early March, where we've hardly been able to buy 75 the past couple months, to say nothing of the broadly-improving (rather than worsening) drought. The ENSO tendency over the preceding ~6 months is not all that different, though, unfortunately. With that said, I'm as far from an expert on seasonal forecasting and global oscillations as anyone, so I'll defer to HM any day.

 

2011 really turned me off to early May. Looking back it does have a tendency to be a big hit or a big miss more often than not. At least later you usually tend to get more regular if smaller days.

 

Tour grouping probably not a horrible business but there are so many these days hard to see how it's that profitable. I'm nervous enough about rolling the dice on 2-3 weeks let alone one tho. 

 

I keep thinking it's gotta turn around at some point but still no real sign of that so maybe it's a lost cause. The d ~10-16 pattern is about as bad as it could possibly get though, so it should turn at least a little better after? I'd want to say even that could be wrong but the Euro and GFS are in fairly close agreement.  Further out.. seems like anyone's guess. I've seen pretty much every possible prediction.

[OKpowdah]

Snow coverage anomalies over North America are pretty remarkable right now

 

 

Compare 2013 to 2006

 

 

[Ian]

Wonder how much the snow cover really matters going forward. It's going to torch away pretty quick. I suppose it should favor cooler/wetter conditions in that region for a while at least which would want to keep some sort of temp gradient in there.  If the jet goes way north it might not matter.  At this point I'm more concerned about the fact that we can't get Gulf moisture north in any real fashion.

[OKpowdah]

Wonder how much the snow cover really matters going forward. It's going to torch away pretty quick. I suppose it should favor cooler/wetter conditions in that region for a while at least which would want to keep some sort of temp gradient in there.  If the jet goes way north it might not matter.  At this point I'm more concerned about the fact that we can't get Gulf moisture north in any real fashion.

 

Yeah I mean, I'll be stoked to watch the first cold front that doesn't clear out the Gulf this season.

 

But I think that at the very least, the snow cover may help establish the low level baroclinic zone further south such that as we get later into the spring, lows don't just take off to the northeast ... so we get the greater helicity and higher LI's with proximity to the surface low.

[icebreaker5221]

No joke. Remarkable how perilous it's been to choose early May in recent times. Honestly, of the past decade, only 2003 and 2007 would've worked out very well for that May 1-10 period. Just can't imagine running a tour service and having to look customers in the eye weeks like this. Then again, so many of them seem relatively content to dink around places like Palo Duro or the Wichitas if all else fails, so maybe we need to get into the biz.

 

Back slightly more on-topic: the 2006 analog is an odd one from a regional perspective, even if the upcoming hemispheric pattern syncs up. Was so relentlessly warm and dry from winter through summer. We were pushing 95 in early March, where we've hardly been able to buy 75 the past couple months, to say nothing of the broadly-improving (rather than worsening) drought. The ENSO tendency over the preceding ~6 months is not all that different, though, unfortunately. With that said, I'm as far from an expert on seasonal forecasting and global oscillations as anyone, so I'll defer to HM any day.

 

 

I agree that the season thus far has differed substantially from 2006.  But interestingly, the pattern did break in 2006 during mid-May, in which a series of long-lived cutoff lows swung their way through the Great Lakes.  

 

 

Anomalous northerlies on the backside actually resulted in a cool spell for the Great Plains.  The torch then went on to establish itself by the end of the month. 

 

 

Interestingly, today's 12Z GFS has a very long-lived cutoff in almost the same location.

[Ian]

Yeah I mean, I'll be stoked to watch the first cold front that doesn't clear out the Gulf this season.

 

But I think that at the very least, the snow cover may help establish the low level baroclinic zone further south such that as we get later into the spring, lows don't just take off to the northeast ... so we get the greater helicity and higher LI's with proximity to the surface low.

 

I hope so. This thread is really depressing. Guess I should be happy we aren't leaving for 8 days past the end of the runs.

[Ian]

I blame Timmer if the season sucks. What's he going to do with his 130k if there are no tornadoes?

[Stebo]

Man the GFS and Euro are what severe weather enthusiasts have for nightmares this time of year. I don't think you could have a worse pattern this time of year than what is being shown.