Central/Western Summer Medium/Long Range Discussions

[Chinook]

Ugh, it's April already. Can't we be done with patterns that look like this?

 

 

If you can't tell, I'm getting a little sick of NW flow with upstream high amplitude ridging...

I have to agree. I saw a similar thing on today's 8-10 day forecast. NW flow makes the severe weather season into a snoozefest. Bring on El Nino, perhaps next winter. It would help the drought in the South and the West.

[thewxmann]

I was watching this for several days, as well, but all the trends are in the wrong direction. Not only is it currently looking like yet another case of mis-timing (i.e., the H5 trough axis is where you want it to be for a chase at 12z Sun), but the 1030 mb high oozing down the Plains is likely to result in a crashing cold front akin to most of our April 2013 setups. Because of the cold air, which will in all likelihood arrive sooner than modeled, I'd be shocked if Sunday amounts to anything. Our only hope is likely to be Saturday, and that requires the stars to align: moisture return on the high end of the guidance envelope and faster timing of the wave.

 

Models are always too fast in ejecting the system and always too robust with moisture return.... this scenario does not seem plausible.

[andyhb]

It seems a lot of people in this thread are eager to get hooked on depression lol.

[brettjrob]

Models are always too fast in ejecting the system and always too robust with moisture return.... this scenario does not seem plausible.

 

I largely agree. The probability of a significant Plains event next weekend is quite low at this time.

[nrgjeff]

This:

It seems a lot of people in this thread are eager to get hooked on depression lol.

 

Little early to cliff dive when peak chase season, defined by slower storm motions and just-right cap, is late April into mid-May. I have not seen one great looking set-up within 5 days bust, not one. A couple perfect prog deals 6-8 days away did not work out, but who believes NWP that far out? Keep Calm, and Chase On.

[1900hurricane]

Not cliff diving here, but I would be lying to you if I said I wasn't getting a little impatient.


Sent from my iPhone

[ZackH]

This:

 

Little early to cliff dive when peak chase season, defined by slower storm motions and just-right cap, is late April into mid-May. I have not seen one great looking set-up within 5 days bust, not one. A couple perfect prog deals 6-8 days away did not work out, but who believes NWP that far out? Keep Calm, and Chase On.

 

I don't think anyone is cliff diving... we are just discussing potential long range developments and showing a bit of displeasure when they trend towards weakening.  Its just something to talk about and since we are all passionate about the weather... and lets face it, there's not much to talk about.  And, in no way do I think this season is going to bust based just on early April activity... but anyway you look at it, slow season or active season, 2014 is waiting extremely late climatology wise on getting started.  Is this a good thing or bad thing for the season?  Way too early to tell, but those are the facts and I don't think its leading anyone to dive off a cliff or give up on the season.  We're just ready to actually see some consistent storms after a long winter.  We may not be at the peak, but we typically are seeing much more activity than we have had thus far in a usual season.

 

After all, this is the long range thread

[andyhb]

Yeah don't look at the CFSv2 SCP site if you want to find anything worth getting interested in. 

[RCNYILWX]

The 12z operational ECMWF still has the cold front surging south late Sunday in KS and OK. However it verbatim appears to have a decent environment in place over the eastern half of OK and southeast KS for much of the day and does show initiation prior to the front. The op GFS on the other hand is much faster with the cold front on Sunday and Saturday appears it would be capped with out much forcing and lacking deep shear.

[brettjrob]

I don't think anyone is cliff diving... we are just discussing potential long range developments and showing a bit of displeasure when they trend towards weakening.  Its just something to talk about and since we are all passionate about the weather... and lets face it, there's not much to talk about.  And, in no way do I think this season is going to bust based just on early April activity... but anyway you look at it, slow season or active season, 2014 is waiting extremely late climatology wise on getting started.  Is this a good thing or bad thing for the season?  Way too early to tell, but those are the facts and I don't think its leading anyone to dive off a cliff or give up on the season.  We're just ready to actually see some consistent storms after a long winter.  We may not be at the peak, but we typically are seeing much more activity than we have had thus far in a usual season.

 

After all, this is the long range thread

 

This. This x1000.

 

I'm sure some of the negativity gets old, mine included. But frankly, the past few years, the "shaddup, it's only [X date], quit whining!" crowd has grown even more annoying. We all know our region's climatology, and don't need a daily reminder that the peak season is still several weeks out.

 

However, when:

 

1) It's April 7

2) Virtually nothing has happened thus far

3) The medium range looks dismal

4) The past three consecutive years in the Plains have been inactive from a "tornado/supercell day count" standpoint

 

there's no denying that the season is off to a bad start. When it was only March 10 and some of us were griping, it could be chalked up to impatience. At this stage, though, we're clearly running behind for a period that matters -- at least, if we make the reasonable assumption that not much else will have happened 10-12 days from now. Every week that passes with dry northwest flow means not only that the late season will have to compensate, but worsening Plains drought, which to some extent feeds back into the chances of that happening.

 

Point: May and June are by far the most important months for storm chasers and for the Plains in general. Years like 2004 and 2010 had little by mid April (though still a bit more than this year), then went on to be spectacular. Counterpoint: those years had an exceptionally active May-June, and it's not as if a dismal March-April is positively correlated with late-season activity. The possibility of a great season remains, but the probability slowly declines every week. There's no silver lining whatsoever to cool and dry weather dominating the time period over which events like 3/13/90 and 3/28/07 and have happened in the best years, especially in the midst of a long-term drought rivaling the Dust Bowl.

[brettjrob]

With that all out of the way, I'd say the trends for Saturday have been slightly positive the past 24 h. I'm not sure that's enough to make it a decent setup, but I haven't given up. The 07/12z ECMWF sets up a tight dryline across central KS, western OK and northwest TX with mid-upper 50s dew points in place. Kinematics look very good in the low-levels, and borderline-sufficient in the mid-upper levels, especially farther S. Moisture will be a limiting factor, and timing still looks slower than what would be ideal, but in the best case some decent dryline supercells could be on the table.

[Chicago Storm]

The 12z operational ECMWF still has the cold front surging south late Sunday in KS and OK. However it verbatim appears to have a decent environment in place over the eastern half of OK and southeast KS for much of the day and does show initiation prior to the front.

Looks far from interesting. Carbon copy of the last event...though the addition of a surging front this time.

[Stebo]

The 12z operational ECMWF still has the cold front surging south late Sunday in KS and OK. However it verbatim appears to have a decent environment in place over the eastern half of OK and southeast KS for much of the day and does show initiation prior to the front. The op GFS on the other hand is much faster with the cold front on Sunday and Saturday appears it would be capped with out much forcing and lacking deep shear.

 

I agree, there could be a modest potential from Tulsa to Dallas with what the 12z Euro is showing, I would say it something to monitor. I would also argue that Monday looks interesting for LA/MS maybe AL later in the day.

[RCNYILWX]

I agree, there could be a modest potential from Tulsa to Dallas with what the 12z Euro is showing, I would say it something to monitor.

Yep, certainly not a higher end setup but in response to Chi Storm, since the overall pattern looks quite poor moving forward, at least the Euro offers *some* potential if it pans out. And did neglect to mention north Texas. Saturday as Brett mentioned could be in play as a best case scenario as well.

[ZackH]

With that all out of the way, I'd say the trends for Saturday have been slightly positive the past 24 h. I'm not sure that's enough to make it a decent setup, but I haven't given up. The 07/12z ECMWF sets up a tight dryline across central KS, western OK and northwest TX with mid-upper 50s dew points in place. Kinematics look very good in the low-levels, and borderline-sufficient in the mid-upper levels, especially farther S. Moisture will be a limiting factor, and timing still looks slower than what would be ideal, but in the best case some decent dryline supercells could be on the table.

 

Saturday still has me interested.  GFS is capped way more than the Euro and I feel like 2000-3000 J/kg will overcome the cap just before sundown if there is sufficient trigger.  I'm more worried about the GFS trigger... subtle pieces of energy being eject from the trough that could be hit or miss (these are also the only localized areas that will have enough shear up the column).  The Euro still is paining a bit better scenario Saturday, but both models break out at least a little bit of precip near the dryline between 00-06z.  As is, its another conditional threat with some nice low level turning at least.  I agree that it has trended positive slightly but I'd still like to see a lot more since Saturday is probably the most desirable chaseable day at this point (but most likely not the most active).

[ZackH]

00z GFS took a small step forward for Saturday's conditional severe dryline setup in KS/OK. Cap is still nuclear and now LCLs could be an issue... but there is now a larger piece of energy being ejected from the upper trough and helping to create more favorable shear. Wondering if the warm/stationary front may actually be an interesting play in MO/IA. Still has a long way to go.

[1900hurricane]

SPC doesn't seem very optimistic about things in the next week.

 

 

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 AM CDT TUE APR 08 2014

VALID 111200Z - 161200Z

...DISCUSSION...
MODELS APPEAR TO BE IN GOOD AGREEMENT FOR THE FRI/D4 AND SAT/D5
PERIOD SHOWING AN ACTIVE NRN-STREAM JET WITH SEVERAL FEATURES
ROTATING AROUND THE UPPER LOW NEAR HUDSON BAY. WITH AN EXPANSIVE
SURFACE HIGH ACROSS THE WRN ATLANTIC AND RIDGE EXTENDING WWD ALONG
THE GULF COAST...IT WILL TAKE SOME TIME FOR THE MORE ROBUST
LOW-LEVEL MOISTURE TO RETURN TO THE GULF COAST STATES AND EVENTUALLY
INTO THE SRN PLAINS. FOR THE D4-D5 PERIOD...ONLY 50S TO NEAR 60S F
DEWPOINTS WILL EXIST OVER THE SRN PLAINS AND LOWER MS VALLEY.

BY SUN/D6...A BROAD SLY LOW-LEVEL JET DEVELOPS IN ADVANCE OF A SRN
STREAM SHORTWAVE TROUGH...RESULTING IN BETTER BOUNDARY LAYER
MOISTURE INTO THE SRN PLAINS/LOWER MS VALLEY. THIS WILL OCCUR AHEAD
OF A SURGING COLD FRONT COURTESY OF A PHASING NRN STREAM TROUGH.
THIS SETUP SHOULD FAVOR BRIEF PERIODS OF WIND OR HAIL AS THE FRONTAL
SURGE UNDERCUTS THE UNSTABLE AIR MASS.

ALTHOUGH TIMING ISSUES EXIST REGARDING THE SRN STREAM FEATURE AND
COLD FRONT...IT APPEARS THE FRONT WILL GENERALLY MOVE QUICKLY AND
PERHAPS UNDERCUT THE SURFACE BASED CONVECTION WHICH WILL MINIMIZE
THE EVENT SEVERITY IN THE D6-D8 TIME FRAME.

..JEWELL.. 04/08/2014

[ZackH]

I'm surprised they don't even give a mention of Saturday... I understand its very conditional, but even in IA/MO there looks to be some severe potential.  Sunday and beyond obviously looks like crap.

[HM]

I just wanted to comment about the drought. If you run the precip correlations with niño region 3.4 on ESRL, you'll get the following images for June-September and October-December.

 

 

 

 

If you then split the years between QBO shear stress behavior, you'll get 9 +QBO to -QBO (like this year) and 8 -QBO to +QBO. Because of the timing of the shear stress, 4 years had to be left out (2004, 2002, 1997 and 1994). Below are the years like 2014 subtracted from the opposite QBO behavior (not scaled). While a small sample, it does look promising for both JJAS and OND for the Plains to pick up some much-need rainfall. The northern-central, western high Plains seem like an easy call, either way. While not shown, the transitioing to E QBO summers/autumns also were noticeably cooler.

 

 

[HM]

I also wanted to show the raw precipitation anomalies compared with 1981-2010. Please be advised that these take into account nothing but ENSO and QBO.

 

 

So you can see that, at the very least, the oncoming -QBO can give better odds for more precipitation than the oncoming +QBO years.

[Chicago Storm]

I'm surprised they don't even give a mention of Saturday... I understand its very conditional, but even in IA/MO there looks to be some severe potential.  Sunday and beyond obviously looks like crap.

They do...But it sounds like they're discounting any decent threat due to moisture concerns.

 

The aforementioned concern seems valid too... Splotchy looking DP maps suggests deeper moisture and mixing out issues.

[tornadotony]

Don't have a whole lot of time, but the GFS actually looks pretty darn impressive for cntl/ern TX on Sunday, say for DFW, Waco, and Tyler.  Surging cold front should still remain N in KS/OK during the day/evening, dryline mixing east, good upper-level support, and mid-upper 60s dewpoints with a sub-1000mb low centered over the Red River and CAPE values in the 2000-3000 J/kg range.  If I didn't know better than to actually say it, I'd say this looks on paper like perhaps the most impressive setup so far this year (not saying much).

[Quincy]

Don't have a whole lot of time, but the GFS actually looks pretty darn impressive for cntl/ern TX on Sunday, say for DFW, Waco, and Tyler.  Surging cold front should still remain N in KS/OK during the day/evening, dryline mixing east, good upper-level support, and mid-upper 60s dewpoints with a sub-1000mb low centered over the Red River and CAPE values in the 2000-3000 J/kg range.  If I didn't know better than to actually say it, I'd say this looks on paper like perhaps the most impressive setup so far this year (not saying much).

This forecast will continue to evolve, but at face value the 12z GFS does look fairly impressive. A more amplified trough than previous runs and with the setup slowing down a bit, there's time for destabilization and for kinematic support to move in:

[brettjrob]

I just wanted to comment about the drought. If you run the precip correlations with niño region 3.4 on ESRL, you'll get the following images for June-September and October-December.

 

If you then split the years between QBO shear stress behavior, you'll get 9 +QBO to -QBO (like this year) and 8 -QBO to +QBO. Because of the timing of the shear stress, 4 years had to be left out (2004, 2002, 1997 and 1994). Below are the years like 2014 subtracted from the opposite QBO behavior (not scaled). While a small sample, it does look promising for both JJAS and OND for the Plains to pick up some much-need rainfall. The northern-central, western high Plains seem like an easy call, either way. While not shown, the transitioing to E QBO summers/autumns also were noticeably cooler.

 

Good news -- thanks for chiming in. Now that El Nino appears almost certain to develop within the next few months, I think it's likely the drought that's crippled much of the High Plains since late 2010 will get beaten down over the next year or so.

 

Don't have a whole lot of time, but the GFS actually looks pretty darn impressive for cntl/ern TX on Sunday, say for DFW, Waco, and Tyler.  Surging cold front should still remain N in KS/OK during the day/evening, dryline mixing east, good upper-level support, and mid-upper 60s dewpoints with a sub-1000mb low centered over the Red River and CAPE values in the 2000-3000 J/kg range.  If I didn't know better than to actually say it, I'd say this looks on paper like perhaps the most impressive setup so far this year (not saying much).

 

Agreed. Yesterday's ECMWF/CMC were actually even slower and farther north, but it looks like the guidance is (for now) converging on a frontal position about 50 mi. either side of I-44 for 00z Mon. DFW will almost certainly be in play. I'm sure the shallow cold airmass will have its way to some extent, but probably not enough to cut them off.

[thewxmann]

Don't have a whole lot of time, but the GFS actually looks pretty darn impressive for cntl/ern TX on Sunday, say for DFW, Waco, and Tyler.  Surging cold front should still remain N in KS/OK during the day/evening, dryline mixing east, good upper-level support, and mid-upper 60s dewpoints with a sub-1000mb low centered over the Red River and CAPE values in the 2000-3000 J/kg range.  If I didn't know better than to actually say it, I'd say this looks on paper like perhaps the most impressive setup so far this year (not saying much).

 

Shallow cold fronts always propagate faster than progged; I wouldn't be surprised if the cold air impinges on DFW by 18Z. The key difference between this and the April 2013 setups is that the main forcing for ascent will actually overspread the warm sector early in this case, given the negative tilt of the shortwave trough. So it probably won't be a cap bust along the dryline, and we could fire off some storms before the cold front ruins everything.

 

DFW's going to be a close call, but Waco could definitely be in play here. Good observation, this wasn't even on my radar until now.

[ZackH]

The latest runs really have me interested in the area from the Red River to Waco and east for Sunday.  I am contemplating giving Saturday a try along the KS/OK border just west of Wichita and then heading down near DFW-ish on Sunday if things keep progressing this way.  Its far from an ideal setup, but it May be the only early season trip I get to try on and I will be out for 10 days at the end of may getting paid as a TA... so I'm having a hard time finding excuses not to at least think about trying this marginal setup.  Other than the fact that if it is as epic a bust as it could be, I will probably not be very happy.

[Quixotic1]

Shallow cold fronts always propagate faster than progged; I wouldn't be surprised if the cold air impinges on DFW by 18Z. The key difference between this and the April 2013 setups is that the main forcing for ascent will actually overspread the warm sector early in this case, given the negative tilt of the shortwave trough. So it probably won't be a cap bust along the dryline, and we could fire off some storms before the cold front ruins everything.

DFW's going to be a close call, but Waco could definitely be in play here. Good observation, this wasn't even on my radar until now.

they have been early, but the last couple have been late. 4/3 it was a good 6 hours late.

[tornadotony]

Shallow cold fronts always propagate faster than progged; I wouldn't be surprised if the cold air impinges on DFW by 18Z. The key difference between this and the April 2013 setups is that the main forcing for ascent will actually overspread the warm sector early in this case, given the negative tilt of the shortwave trough. So it probably won't be a cap bust along the dryline, and we could fire off some storms before the cold front ruins everything.

 

DFW's going to be a close call, but Waco could definitely be in play here. Good observation, this wasn't even on my radar until now.

I would be quite surprised if the models are over a whole state's width off in the progress of the cold airmass.  Faster?  Sure, but I don't think it'll be anywhere near DFW by 18z.  00z maybe, but not 18z.

[tornadotony]

they have been early, but the last couple have been late. 4/3 it was a good 6 hours late.

This is quite a bit different of an airmass than the one on 4/3...much shallower and colder.  I think Jim's got the right idea, but his assertion of the potential for an 18z impingement on DFW is likely too ambitious.

[brettjrob]

This is quite a bit different of an airmass than the one on 4/3...much shallower and colder.  I think Jim's got the right idea, but his assertion of the potential for an 18z impingement on DFW is likely too ambitious.

 

Yeah. It wouldn't be the most shocking thing in the world if Jim's 18z prediction verified, but I doubt it. The GGEM still has a slower front well N of I-40 by 00z Mon; plus, it's mid-April, not February. The usual model biases WRT shallow cold fronts must still be accounted for, but unless even the global models start trending SE soon, I'm thinking Sunday's afternoon-evening threat should extend at least as far NW as roughly Graham-Ardmore-McAlester.