Central/Western Summer Medium/Long Range Discussions

[ingyball]

The latest GFS run has some nice cape values over Southern Kansas, Oklahoma, and North Texas next Thursday and Friday.

[jojo762]

The latest GFS run has some nice cape values over Southern Kansas, Oklahoma, and North Texas next Thursday and Friday.

the 29/30th? Indeed it does, but with almost no shear in place... Interesting the GFS does produce some precip in this area... Any storms that do form would be entirely diurnally driven

[Thunder Road]

These are the storms I always wanted to see as a kid. Tho time for some tubes...

 

Indeed.  I could really go for some condensation of the vertically-oriented, rotating variety.

[andyhb]

Small note, but what the 00z GFS was suggesting @ 144 hrs was highly reminiscent of 5/15 last year.

[Jayhawkers]

Small note, but what the 00z GFS was suggesting @ 144 hrs was highly reminiscent of 5/15 last year.

a few tornadoes occurred that day, including an EF-3 and an EF-4... That also was a see text day up until D1, when it suddenly became high-end slgt risk

[Quincy]

Still kind of like the looks of Sunday. TX/OK panhandles into SW KS if the Euro is correct. 12z run shows ~2000 J/kg SBCAPE ahead of the surface low, which is along the CO/KS border at 18z. Kinematic support isn't overly impressive, but the LLJ kicks up a bit by 00z as the UL trough advances eastward.

Apparently my earlier post went to the wrong thread:

"Day 4 (Saturday) outlook issued for the southern High Plains. Includes far eastern New Mexico and much of western Texas."

[Thundersnow12]

Small note, but what the 00z GFS was suggesting @ 144 hrs was highly reminiscent of 5/15 last year.

 

Funny, I said that exact same thing to myself about the 12z GFS yesterday as well. Easy to remember since I was chasing and saw tornadoes that day in TX. 

[AgeeWx]

There's still time for things to change, but in the meantime the 00Z GFS has taken a step-back regarding the threat for Saturday along the D/L in Texas.

[AgeeWx]

The 00Z GFS, like the 12Z Euro solution, doesn't keep the closed H5 circulation for Saturday but presents it as an open wave. Certainly something to watch.

[ZackH]

Hmmm... I actually like the 00z GFS solution quite a bit more than the early day runs.  Of particular note in the long rang, however, is the threat the GFS is hinting at near the MT/ND border on Wednesday which could be the most significant threat in the long range.  Still, Saturday, Sunday, Monday, and Tuesday all hold some potential in TX. Liking Monahans to Lubbock to Spur to Winters in Texas Saturday through Tuesday respectively.  Although, if the ND/MT threat materializes, will probably need to make Tuesday a travel day.

 

The NAM looks like garbage thus far, but its the NAM 60+ hours out.

[andyhb]

Of particular note in the long rang, however, is the threat the GFS is hinting at near the MT/ND border on Wednesday which could be the most significant threat in the long range.

 

Would probably be potential in the southern Prairie provinces D2 taken verbatim, especially in MB.

[1900hurricane]

Monday and/or Tuesday has lots of sleeper potential down in Texas in my opinion. Speed shear is quite lacking, but directional profiles actually look like they could be quite nice. Someone mentioned 5/15/13 earlier and this could have a similar severe weather potential IF the nice directional profiles materialize.

[andyhb]

Mid/long range 12z Euro looks pretty awful, that cut off forces a ridge over the worst possible place.

[Thunder Road]

I was just about to bail on going south, but the 18z GFS, and really the Texas Tech WRF, have kept me in it.

 

Take a look at the TTU WRF's 12z run, valid 20z Sat at Lubbock:

 

 

It's really backing the low-level flow more than the NAM/GFS.  Correspondingly, 0-1 km and 0-3 km EHI values are ridiculously high along the I-27 corridor.  It's run at 3 km, so maybe this is due to localized orography?  I've always heard that the caprock escarpment is almost as magical as the Palmer Divide, but I've never experienced it first hand.

 

It also kills off the overnight precip with a few hours break before new convection fires, which is something the NAM isn't doing.

[Ian]

Coming south was pretty awesome today. Maybe this pattern does suck.

[andyhb]

I was just about to bail on going south, but the 18z GFS, and really the Texas Tech WRF, have kept me in it.

 

Take a look at the TTU WRF's 12z run, valid 20z Sat at Lubbock:

 

Just took a more in depth look at that depiction, that would be a fairly classic Caprock magic setup with the strongly backed low level flow and 60s Tds nosing into the region (with correspondingly low LCL heights). With that said, I would think everyone and their dog would be out to chase it if it did happen.

[messier77]

Mid/long range 12z Euro looks pretty awful, that cut off forces a ridge over the worst possible place.

 

Yeesh.  I'm heading out for my annual chasecation 6/1-6/8.  Just took a look at the GFS.  Mid/upper level winds look terrible on the long range.  At least there will be plenty of moisture.

 

Consolation prize: it is extra long range modeling, hopefully things change.

[Thunder Road]

Coming south was pretty awesome today. Maybe this pattern does suck.

 

I wasn't even paying attention down there.  What did you guys catch today?  We chased DCVZ showers and were done before Denver rush hour even started.

[Ian]

I wasn't even paying attention down there. What did you guys catch today? We chased DCVZ showers and were done before Denver rush hour even started.

Got on severe cells near Tucumcari. Looked ok for a bit but nothing too exciting. Didn't expect much from today but thought maybe the shear would cooperate better than it did. We checked into a hotel by 5 and did laundry.

[ingyball]

Take a look of this AFD that came out of NWS Fort Worth today. If it pans out then the Metroplex could get a lot of much needed rain next week, though with a price of flooding. 

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
336 PM CDT THU MAY 22 2014

.DISCUSSION...
A LARGE UPPER LEVEL LOW OVER CALIFORNIA AND NEVADA WILL REMAIN
NEARLY STATIONARY THROUGH FRIDAY...BUT A SHORTWAVE TROUGH NOW
MOVING ACROSS NORTHERN MEXICO WILL ROTATE NORTHEAST INTO TEXAS.
THIS SHORTWAVE IS RESPONSIBLE FOR THE SIGNIFICANT CONVECTIVE
INCREASE THIS AFTERNOON ACROSS THE MOUNTAINS OF MEXICO...FAR WEST
TEXAS AND NEW MEXICO. MOST OF THIS CONVECTION WILL STRUGGLE TO
MOVE EASTWARD DUE TO THE SOUTHERLY STEERING FLOW...AND THUS WILL
REMAIN WEST OF THE CWA TONIGHT.

HOWEVER THE CONVECTION WILL INJECT MOISTURE INTO THE MID-UPPER
LEVELS AND RESULT IN A PLUME OF SATURATED AIR ALOFT THAT WILL
TRACK EASTWARD INTO THE WESTERN CWA BY MORNING. IN ADDITION TO
THIS MOISTURE...TONIGHT/S CONVECTION WILL ALSO ENHANCE THE
VORTICITY WITHIN THIS LAYER. TECHNICALLY THE RELEASE OF LATENT
HEAT VIA CONVECTION ALWAYS INCREASES VORTICITY...BUT MOST OF THE
TIME THIS VORTICITY IS QUICKLY SHEARED APART BY THE SYNOPTIC
SYSTEM WHICH CREATED THE CONVECTION IN THE FIRST PLACE. HOWEVER IN
LATE SPRING AND SUMMER WHEN SYNOPTIC SYSTEMS ARE WEAKER AND HAVE
LIGHTER WIND FIELDS...THIS CONVECTIVELY INDUCED VORTICITY MAXIMA
CAN HOLD TOGETHER FOR MANY HOURS BEYOND THE DEATH OF THE PARENT
CONVECTION. IF THIS VORTICITY IS STRONG ENOUGH...IT WILL SHOW UP
AS MESOSCALE SWIRLS OR VORTICES WE CAN SEE ON SATELLITE CALLED A
MESOSCALE CONVECTIVE VORTEX OR MCV. IT IS POSSIBLE WE WILL SEE ONE
OR TWO OF THESE TOMORROW ON SATELLITE...BUT EVEN IF WE CANT...WE
DO EXPECT THE ENHANCED VORTICITY TO BE NESTED WITHIN THIS MOISTURE
PLUME TO AID IN LIFTING OF THE AIR.

FOR THE FRIDAY FORECAST HAVE INCREASED CLOUD COVER FOR THE ENTIRE
AREA AS DENSE MID-HIGH LEVEL CLOUDS ARE LIKELY WITH THIS ARRIVING
MOISTURE PLUME. THIS MEANS HIGHS WILL BE COOLER...ESPECIALLY IN
THE WESTERN ZONES. HAVE ALSO ADDED A LOW CHANCE OF SHOWERS AND A
FEW STORMS TO AREAS WEST OF I-35...AND IT IS POSSIBLE A FEW
SPRINKLES MAY SPILL EASTWARD INTO THE CENTRAL ZONES BY AFTERNOON.
SINCE MOST OF THE MOISTURE IS IN THE MID-UPPER LEVELS WHERE LAPSE
RATES ARE MOIST ADIABATIC...INSTABILITY WILL BE LIMITED...AND SOME
OF THE PRECIP MAY EVAPORATE BEFORE REACHING THE GROUND. SHOWERS
SHOULD BE THE PREDOMINANT MODE...BUT A FEW STORMS WILL BE
POSSIBLE. GENERALLY QUIET WEATHER IS EXPECTED FROM FRIDAY NIGHT
INTO SATURDAY NIGHT...WITH MOST OF THE CONVECTION REMAINING TO OUR
WEST AND NORTHWEST AHEAD OF THE SLOW EASTWARD MOVING UPPER LEVEL
LOW. LIGHT TO MODERATE S/SE WINDS WILL PREVAIL WITH LOWS IN THE
MID-UPPER 60S AND HIGHS IN THE MID-UPPER 80S. WILL KEEP SLIGHT
CHANCE POPS IN THE FAR NORTHWEST ZONES DURING THIS PERIOD AS SOME
ACTIVITY MAY SKIRT THIS AREA BEFORE HEADING INTO OKLAHOMA.

IT IS BECOMING APPARENT THAT THE UPPER LEVEL LOW IS GOING TO BE
RESPONSIBLE FOR QUITE A BIT OF RAINFALL SOMEWHERE IN THE REGION.
THIS HEAVY RAIN MAY NOT IMPACT OUR CWA DIRECTLY...THAT ALL DEPENDS
ON THE ULTIMATE TRACK...SPEED AND EVOLUTION OF THE UPPER LOW.
MODEL GUIDANCE CONTINUES TO DIVERGE WITH THIS FEATURE AS FORECAST
TIME INCREASES...BUT THERE IS AT LEAST GOOD CONSISTENCY NOW ON THE
LOW TAKING A MORE SOUTHERLY TRACK THROUGH OKLAHOMA MONDAY-TUESDAY.

THIS MEANS CHANCES OF SHOWERS/STORMS WILL INCREASE ON SUNDAY AND
SUNDAY NIGHT FROM THE WEST. STORMS WILL LIKELY FIRE CLOSE TO THE
WESTERN CWA SUNDAY AFTERNOON...CLOSE ENOUGH TO TRACK INTO THE NW
HALF OF THE CWA SUNDAY EVENING/NIGHT. AS THE UPPER LOW MOVES A
LITTLE FARTHER EAST BY MONDAY...THESE STORMS SHOULD DEVELOP WITHIN
THE CWA MONDAY AND TUESDAY...AS WE WILL BE IN A FAVORABLE REGION
OF UPPER LEVEL LIFT AND RICH GULF MOISTURE. WHILE SHEAR AND
INSTABILITY WILL BE ON THE LOW SIDE...SOME DISORGANIZED THREAT OF
SEVERE STORMS WILL BE POSSIBLE DURING THE WARMEST PARTS OF THE
DAY. HOWEVER...THE INCREASED RAIN AND CLOUDS WILL TEND TO KEEP
HIGH TEMPS IN THE LOW TO MID 80S...LIMITING CAPE VALUES. THE
HIGHEST RAIN AMOUNTS THROUGH TUESDAY WILL BE WEST AND NORTHWEST
OF THE CWA. HOWEVER WITH WIND PROFILES DISPLAYING
ORGANIZATION...CONVECTION WILL HAVE THE POTENTIAL TO DEVELOP INTO
COMPLEXES THAT MAY LEAD TO CELL TRAINING AND LOCALLY HEAVY AMOUNTS
OF RAIN IN OUR AREA. THIS IS MOST LIKELY OVER THE NORTHWEST CWA
SUNDAY NIGHT...AND THE NORTHERN CWA MONDAY AND TUESDAY.

BY WEDNESDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE FATE
OF THE UPPER LOW. WHAT WE ARE SEEING IN THE MODEL DATA TODAY IS
REALLY QUITE INTERESTING. ALL MODELS ARE INDICATING A TRANSITION
OF THIS COLD-CORE UPPER LEVEL LOW TO A WARM-CORE SYSTEM. IN
SIMPLISTIC TERMS...THIS MEANS THAT THE REPEATED ROUNDS OF
CONVECTION OVER SEVERAL DAYS RELEASE SO MUCH HEAT INTO THE
ATMOSPHERE THAT A BUBBLE OF WARM AIR AND HIGH VORTICITY BUILDS UP
IN THE MID-UPPER LEVELS OF THE ATMOSPHERE. THESE WARM-CORE SYSTEMS
ARE ESSENTIALLY WHAT TROPICAL CYCLONES ARE...A LOW AND MID LEVEL
CYCLONE LOCATED BENEATH AN UPPER LEVEL ANTICYCLONE. OBVIOUSLY
WHEN THESE WARM CORE CYCLONES ARE OVER LAND...THERE IS NO WARM
WATER...AND THUS NOT ENOUGH HEAT ENERGY TO GENERATE A STRONG LOW
PRESSURE CENTER AND STRONG SURFACE WINDS. BUT AS LONG AS THERE IS
SOME SUPPLY OF TROPICAL MOISTURE AVAILABLE...THESE SYSTEMS CAN
PRODUCE COPIOUS AMOUNTS OF RAINFALL AND FLOODING RISKS...OFTEN
AT NIGHT. THE STEERING OF THESE SYSTEMS ARE SIMILAR TO TROPICAL
CYCLONES...AND ANY WIND SHEAR WILL DESTROY THEM VERY QUICKLY.

MODEL GUIDANCE ACTUALLY SHOWS AN UPPER LEVEL 200MB HIGH BUILDING
IN OVER THE SOUTH CENTRAL US BY MIDWEEK AND THUS THE SYSTEM WILL
REMAIN IN A LOW SHEAR ENVIRONMENT...AND ALSO CLOSE ENOUGH TO THE
GULF FOR A SUPPLY OF RICH MOISTURE. IN FACT IT APPEARS THAT THE
MAIN UNCERTAINTIES WITH THIS SYSTEM IS WHEN WILL IT MAKE ITS
TRANSITION TO WARM-CORE AND BEGIN BEHAVING LIKE A REMNANT TROPICAL
CYCLONE...AND WHERE IT WILL GO. THE GFS SHOWS THE WARM-CORE
TRANSITION TAKING PLACE FIRST...AND THAT EXPLAINS WHY IT IS THE
FIRST TO DROP THE LOW SOUTH AND INTO TEXAS BY WEDNESDAY NIGHT AND
THURSDAY. THE NOGAPS HAS THE LOW DROPPING INTO LOUISIANA. THE
CANADIAN/UKMET/ECMWF SHOW THE LOW STALLING OVER ARKANSAS. AGAIN
THIS SYSTEM IS GOING TO BE RESPONSIBLE FOR SOMEONE GETTING WAY TOO
MUCH RAIN TOO FAST...AND JUST LIKE A TROPICAL SYSTEM IT IS JUST
TOO HARD TO PREDICT WHERE IT IS GOING TO BE 5 TO 10 DAYS FROM NOW.
NOT ONLY IS ITS PATH DEPENDENT ON SUBTLE UPPER LEVEL STEERING
FEATURES...BUT ALSO ON THE AMOUNT OF CONVECTION THE SYSTEM
GENERATES WHICH DETERMINES WHEN IT MAKES ITS WARM-CORE TRANSITION.
SO FOR THE WEDNESDAY AND THURSDAY FORECAST...WILL KEEP SOME LOW
POPS GOING IN THE EASTERN ZONES...AND WE WILL CONTINUE TO WATCH.

TR.92

[Brewers]

Our chase group will be out from 5/26-6/1. Will probably just head to the Northern Plains and hope for the best. The upper level trough and SW flow over the NW US makes me at least optimistic we can salvage something. Beyond that, it definitely looks like a summer-like pattern is starting to take hold.

[andyhb]

Goodness the newly run 00z Euro/EPS is

 

We thought 2012 was poor...the jet literally goes straight into a Summer pattern, and that ridge is just in a terrible position.

[brettjrob]

Goodness the newly run 00z Euro/EPS is

 

We thought 2012 was poor...the jet literally goes straight into a Summer pattern, and that ridge is just in a terrible position.

 

This year is everything we feared 2013 would be up until the May extravaganza, and then some. Worst chase year since 1988, unless June pulls a rabbit out in defiance of current modeling. And I'd rather have lived through 1988 than this, since at least it wasn't a brutally cold winter and early spring. To jump straight from that crap to a death ridge, if that indeed transpires, makes 2014 about as freakishly miserable as it gets.

 

It looks like 2014 will land in good company among recent years with rapid El Nino development during the spring/summer: 1997, 2002, 2006 and 2009. And it might be the worst of the bunch for the Plains.

[JoMo]

This year is everything we feared 2013 would be up until the May extravaganza, and then some. Worst chase year since 1988, unless June pulls a rabbit out in defiance of current modeling. And I'd rather have lived through 1988 than this, since at least it wasn't a brutally cold winter and early spring. To jump straight from that crap to a death ridge, if that indeed transpires, makes 2014 about as freakishly miserable as it gets.

 

It looks like 2014 will land in good company among recent years with rapid El Nino development during the spring/summer: 1997, 2002, 2006 and 2009. And it might be the worst of the bunch for the Plains.

 

Euro Weeklies weren't too excited about much of anything for June it looks like. Definitely not any large troughs pushing into the Plains.

[Jayhawkers]

Last few years have been almost the exact same in a simple point-of-view. Few tornado outbreaks occur, or few good setups a occur. But the outbreaks that do occur are pretty major either in number of tornadoes or in devastation, or both (4/27-28/14, 5/30/13, 5/21/13, 4/14/12, 4/25-28/11, 5/22/11, 3/2/11, etc... Sure I missed a day in there) EDIT: really goes all the way back to ~2007

[andyhb]

What?

 

2008, 2010 and 2011 were full of significant events, it's only this year and the last two that it applies to. 

[brettjrob]

Last few years have been almost the exact same in a simple point-of-view. Few tornado outbreaks occur, or few good setups a occur. But the outbreaks that do occur are pretty major either in number of tornadoes or in devastation, or both (4/27-28/14, 5/30/13, 5/21/13, 4/14/12, 4/25-28/11, 5/22/11, 3/2/11, etc... Sure I missed a day in there) EDIT: really goes all the way back to ~2007

 

I think that was very much the case for 2011-2013, especially if you focus on the Plains. Each of those three years battled significant drought and very long stretches of highly-unfavorable synoptic patterns, but still managed at least one really big day apiece. 2011 had several (5/22, 5/24, 6/20) -- however, it was also entirely dead for crucial periods like 5/1-5/18 and 5/25-6/18. Maybe the oddest year to me was 2012, simply because it had such a prolific day in 4/14/12 while being so impotent otherwise. In recent history, the huge I-35 outbreak days have tended to occur in years at least moderately-favorable as a whole (e.g., 1990, 1991, 1999, 2010 -- granted, not a big sample size). Take that one day out, and 2012 on the Plains is almost as worthless as 2014 has been thus far.

 

I don't necessarily agree about the 2007-2010 period, though. Those years seemed much more well-rounded/balanced in both time and space during the Plains season -- with the slight exception of 2009, clearly the weakest of that bunch. As with all but the very top-tier years, there were down periods, some lasting a few weeks. But you never really went more than 4 weeks without a noteworthy event in the Plains from March to June. From 2011 onward, it's really been the lack of long-lasting favorable patterns (except 5/15-5/31 last year) killing us out here. Stretches like 5/10-6/20 in 2010, or 5/22-6/20 in 2008, seem like such a distant memory these days.

[Jayhawkers]

I think that was very much the case for 2011-2013, especially if you focus on the Plains. Each of those three years battled significant drought and very long stretches of highly-unfavorable synoptic patterns, but still managed at least one really big day apiece. 2011 had several (5/22, 5/24, 6/20) -- however, it was also entirely dead for crucial periods like 5/1-5/18 and 5/25-6/18. Maybe the oddest year to me was 2012, simply because it had such a prolific day in 4/14/12 while being so impotent otherwise. In recent history, the huge I-35 outbreak days have tended to occur in years at least moderately-favorable as a whole (e.g., 1990, 1991, 1999, 2010 -- granted, not a big sample size). Take that one day out, and 2012 on the Plains is almost as worthless as 2014 has been thus far.

I don't necessarily agree about the 2007-2010 period, though. Those years seemed much more well-rounded/balanced in both time and space during the Plains season -- with the slight exception of 2009, clearly the weakest of that bunch. As with all but the very top-tier years, there were down periods, some lasting a few weeks. But you never really went more than 4 weeks without a noteworthy event in the Plains from March to June. From 2011 onward, it's really been the lack of long-lasting favorable patterns (except 5/15-5/31 last year) killing us out here. Stretches like 5/10-6/20 in 2010, or 5/22-6/20 in 2008, seem like such a distant memory these days.

I'd disagree about 2009 and 2010. For 2009 there was really only one "big" plains day, 5/13/09, and 2010 has two big days as well (5/10/10, and 5/24/10) obviously may 10th was a tremendous day but the other 2 from both years were meh IMO in terms of tornado-production. But upon looking at 2007/2008 again I take that back, they were both big plains years. EDIT: but relatively speaking, to the past few years, as you were saying, they were actually pretty decent years.

[Jayhawkers]

What?

2008, 2010 and 2011 were full of significant events, it's only this year and the last two that it applies to.

lol. Misspoke about '11 and '08 but, 2010 had two great/good days that's it. Got too focused on the two historical events in '11 that I got side tracked. EDIT: also trying to keep it forum specific... Central plains basically... 2011 had literally one good plains event 5/24/11, the other day earlier in the month was much less impressive. But as a whole for the CONUS, 2011 was indeed a historical year.

[andyhb]

I'd disagree about 2009 and 2010. For 2009 there was really only one "big" plains day, 5/13/09, and 2010 has two big days as well (5/10/10, and 5/24/10) obviously may 10th was a tremendous day but the other 2 from both years were meh IMO in terms of tornado-production. But upon looking at 2007/2008 again I take that back, they were both big plains years. EDIT: but relatively speaking, to the past few years, as you were saying, they were actually pretty decent years.

 

5/22 (Bowdle),  6/16-17 (Dupree, SD tornado machine on 6/16 then the ND/MN tornado outbreak on 6/17), 5/31 (Campo), etc. etc.