May 15th - 20th Plains Storm/Severe disco

[Stebo]

It's almost always wise to be pessimistic.

 

Though I did text Katie yesterday that one day could high risk. Weeniecast. I'm just happy there will be storms.. and will try to forget our last two straight drives ended up in busts. 

 

When are you guys heading out there?

[Ian]

When are you guys heading out there?

 

tomorrow early/mid afternoon hopefully. planning on chasing sat. Early NE target prob makes it more likely for a bust as we've busted there on two other occasions.

[brettjrob]

It's almost always wise to be pessimistic.

 

Though I did text Katie yesterday that one day could high risk. Weeniecast. I'm just happy there will be storms.. and will try to forget our last two straight drives ended up in busts. 

 

Are you guys marathoning it for Saturday? Definitely wouldn't blame you for not, given the extra distance on top of everything else.

 

I've surely developed some storm snobbery over time, but I think most of it has fallen away the past 13 months . I guess I'm very sensitive to expectations, though. When the ceiling is as high as it's looked for Sunday, letdowns are painfully easy to come by. I'm just seeing a lot of unconditional hype (mainly elsewhere), worse than usual, when to me the downside of this from 72 hrs out is well above average for a big setup in late May. A significant outbreak is still on the table, but in my eyes, the less favorable solutions aren't just "a decent outbreak one peg lower" -- but more like nontornadic sups or even a cap bust.

[Stebo]

tomorrow early/mid afternoon hopefully. planning on chasing sat. Early NE target prob makes it more likely for a bust as we've busted there on two other occasions.

 

Ahh well good luck to you guys out there!

[Ian]

Are you guys marathoning it for Saturday? Definitely wouldn't blame you for not, given the extra distance on top of everything else.

 

I've surely developed some storm snobbery over time, but I think most of it has fallen away the past 13 months . I guess I'm very sensitive to expectations, though. When the ceiling is as high as it's looked for Sunday, letdowns are painfully easy to come by. I'm just seeing a lot of unconditional hype (mainly elsewhere), worse than usual, when to me the downside of this from 72 hrs out is well above average for a big setup in late May. A significant outbreak is still on the table, but in my eyes, the less favorable solutions aren't just "a decent outbreak one peg lower" -- but more like nontornadic sups or even a cap bust.

 

I think we pulled that trigger when Sat looked bigger.. tho given we are on limited (even if lengthy) time, and the setup is there, might as well try for it. I guess if for some reason we didn't make it for Sat wouldn't be tragic necessarily.  That kind of day can be pretty rewarding of course.. so hard to say no chance. Part of you still thinks this is 2013 and who knows how much more will be out there even over three weeks as well.  Hungry for a good storm... sleep can come later.

 

I've never been as enamored with the OK target as most people. In some ways it might be optimal to figure out how to play the northern targets. Could definitely see "the day" produce in a place like IL (or MO, ick) though.  Seems hard to figure out how we get out of a prolonged event as it's shown without a solid number of tornadoes, but from a chasing perspective I could see it being a nightmare.

 

Our best advantage is storms around here blow in general so even multi-cell crap is OK for a while.

[wxmeddler]

 

Our best advantage is storms around here blow in general so even multi-cell crap is OK for a while.

 

Yup, this is my first time out with plains storms, so anything with 2500+ cape and even a bit of shear is going to look spectacular to me. Flip side is that after this trip, all the storms back at home this summer are going to look like $h*t.

[WxKevinM]

plan on getting to Sioux Falls Friday night, , probably play Nebraska Saturday, and Kansas City  and points north Sunday as I'm limited with time...

[Ian]

Yup, this is my first time out with plains storms, so anything with 2500+ cape and even a bit of shear is going to look spectacular to me. Flip side is that after this trip, all the storms back at home this summer are going to look like $h*t.

 

I hope we get to stay at the amusement park hotel in Kearney Sat night. They have good breakfast.

[Minnesota Meso]

For us in the Northern Plain, it looks like South Dakota is still in play for Saturday, as for points further east ie: upper Mississippi Valley,  it looks like we will have a hard time  co-locating the best shear, cape and QPF, until maybe Sunday afternoon, early evening.  The Nam is showing some directional shear by then but I don't by it, although a quick look at the GFS may support it. The problem with the GFS is that it shows QPF all day on Sunday so whatever cape it's showing may well be over done.  As far as further south, I wonder if 4-5k cape with double digit LI's will support strong capping problems.

[andyhb]

00z GFS isn't quite as impressive with the Sunday threat as the previous run, but the parameters become even more impressive than the last run had on Sunday, but this time on Monday with the second jet streak (in Oklahoma).

[Radtechwxman]

00z GFS isn't quite as impressive with the Sunday threat as the previous run, but the parameters become even more impressive than the last run had on Sunday, but this time on Monday with the second jet streak (in Oklahoma).

yea models really seemed to have shifted course tonight. could be due to sampling and the model trying to grasp the dynamics of the system. def am going to look for trends. 12z runs tmrw will be interesting. the one thing I am not liking after seeing the runs tonight is how the area of good directional shear has shrunk considerably to a very narrow corridor. looking at water vapor imagery it almost looks like this system is already taking on a neg tilt as it comes on shore. correct me if I am wrong

[KSWx]

This Weather Channel timeline-piece on the Texas tornadoes is a good read.

 

 

http://www.weather.com/news/tornado-central/tornadoes-texas-granbury-cleburne-20130516

[Minnesota Meso]

The new GEM is in.  For Saturday it shows very little QPF in the OK/KS area.  It still likes the SD area with secondary QPF area over the SW corner of IA, that seems to be isolated.  Otherwise it looks like a capped environment.  What looked so promising 24-36 hours ago is quickly waning IMO.

[Stebo]

The new GEM is in.  For Saturday it shows very little QPF in the OK/KS area.  It still likes the SD area with secondary QPF area over the SW corner of IA, that seems to be isolated.  Otherwise it looks like a capped environment.  What looked so promising 24-36 hours ago is quickly waning IMO.

 

The stuff in OK/KS would be more discrete, you wouldn't see massive QPF blobs there, it does show QPF though down into those regions. This to me would spell initiation down there.

[KSWx]

 

Hatched area has grown significantly.

[andyhb]

D3 out, rather large 30%/hatched area in place.

 

DAY 3 CONVECTIVE OUTLOOK     NWS STORM PREDICTION CENTER NORMAN OK   0228 AM CDT FRI MAY 17 2013      VALID 191200Z - 201200Z      ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF GREAT   PLAINS...UPPER MS VALLEY AND MID-MO VALLEY...      ...SRN AND CNTRL PLAINS...   AN UPPER-LEVEL LOW IS FORECAST TO DEVELOP ACROSS THE NRN PLAINS   SUNDAY AS A NEGATIVELY-TILTED UPPER-LEVEL TROUGH MOVES EWD INTO THE   SRN AND CNTRL PLAINS. AT THE SFC...A COLD FRONT IS FORECAST TO MOVE   SEWD INTO THE SRN AND CNTRL PLAINS WITH DEWPOINTS AHEAD OF THE FRONT   IN THE MID TO UPPER 60S F. THIS SHOULD RESULT IN MODERATE TO STRONG   DESTABILIZATION BY LATE SUNDAY AFTERNOON FROM ERN KS SSWWD INTO   ECNTRL OK. IN SPITE OF THE INSTABILITY...A STRONG CAPPING INVERSION   SHOULD HOLD BACK CONVECTIVE INITIATION UNTIL LATE AFTERNOON. MODEL   FORECASTS SUGGEST STORMS WILL INITIATE ALONG THE FRONT BY 00Z/MON   WITH AN MCS ORGANIZING AND MOVING ESEWD ACROSS THE REGION. STRONG   INSTABILITY COMBINED WITH IMPRESSIVE DEEP LAYER SHEAR PROFILES WILL   CREATE CONDITIONS FAVORABLE FOR SEVERE THUNDERSTORMS. THERE EXISTS   THE POSSIBILITY FOR WIDESPREAD SEVERE WEATHER INCLUDING A   SIGNIFICANT SEVERE WEATHER EVENT.      FORECAST SOUNDINGS AT 00Z/MON FROM KANSAS CITY SSWWD TO TULSA AND   OKLAHOMA CITY SHOW MLCAPE VALUES OF 2500 TO 3500 J/KG WITH 0-6 KM   SHEAR IN THE 45 TO 55 KT RANGE. A MID-LEVEL JET IS FORECAST TO MOVE   THROUGH THE BASE OF THE UPPER-LEVEL TROUGH HELPING TO INCREASE DEEP   LAYER SHEAR PROFILES AS THE EVENT UNFOLDS. THIS ALONG WITH STEEP   MID-LEVEL LAPSE RATES SHOULD BE IDEAL FOR INTENSE SUPERCELL   DEVELOPMENT. LARGE HAIL INCLUDING HAILSTONES OF GREATER THAN 2   INCHES IN DIAMETER WILL BE POSSIBLE WITH THE MORE DOMINANT   SUPERCELLS. IN ADDITION...A LOW-LEVEL JET IS FORECAST TO INTENSIFY   EARLY SUNDAY EVENING WHICH SHOULD CREATE LOW-LEVEL SHEAR PROFILES   FAVORABLE FOR TORNADOES. A FEW STRONG TORNADOES MAY ALSO OCCUR   ESPECIALLY IF SUPERCELLS CAN REMAIN DISCRETE EARLY SUNDAY EVENING. A   WIND DAMAGE THREAT MAY ALSO DEVELOP AND COULD BECOME ENHANCED IF A   LINEAR MCS ORGANIZES.      ...NRN PLAINS/UPPER MS VALLEY/MID-MO VALLEY...   AN UPPER-LEVEL LOW IS FORECAST TO DEVELOP ACROSS THE NRN PLAINS ON   SUNDAY AS SOUTH TO SOUTHWEST FLOW REMAINS IN PLACE ACROSS THE MID-MO   VALLEY AND UPPER MS VALLEY. AT THE SFC...A LOW IS FORECAST TO MOVE   SLOWLY ACROSS THE NRN PLAINS WITH A TROUGH EXTENDING SWD INTO THE   MID-MO VALLEY. THE SFC TROUGH SHOULD BE THE FOCUS FOR CONVECTIVE   DEVELOPMENT SUNDAY AFTERNOON. THE MODELS SUGGEST SEVERAL   THUNDERSTORM CLUSTERS OR AN MCS WILL DEVELOP AND MOVE NEWD ACROSS   THE REGION. A MODERATELY UNSTABLE AIRMASS IS FORECAST ALONG WITH   STRONG DEEP LAYER SHEAR PROFILES SUGGESTING THAT WIDESPREAD SEVERE   THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE SUNDAY AFTERNOON AND   EVENING.      FORECAST SOUNDINGS AT OMAHA AND DES MOINES AT 21Z/SUN SHOW MLCAPE   VALUES IN THE 2000 TO 3000 J/KG RANGE WITH 40 TO 50 KT OF DEEP LAYER   SHEAR. THIS COMBINED WITH STEEP LAPSE RATES SHOULD SUPPORT   SUPERCELLS WITH LARGE HAIL. HAILSTONES OF GREATER THAN 2 INCHES WILL   BE POSSIBLE IN THE MID-MO VALLEY WHERE THE STRONGEST INSTABILITY IS   FORECAST. A FEW TORNADOES MAY ALSO OCCUR WITH THE MORE DOMINANT   SUPERCELLS. THE SEVERE THREAT SHOULD BE MORE ISOLATED ACROSS ERN   PARTS OF THE NRN PLAINS AND IN THE UPPER MS VALLEY WHERE INSTABILITY   IS FORECAST TO BE WEAKER THAN IN AREAS TO THE SOUTH.      ..BROYLES.. 05/17/2013

[andyhb]

Day 4 for Monday shifted west and shrunk a bit from previous.

 

DAY 4-8 CONVECTIVE OUTLOOK    NWS STORM PREDICTION CENTER NORMAN OK  0357 AM CDT FRI MAY 17 2013    VALID 201200Z - 251200Z     ..DISCUSSION    THE MEDIUM RANGE MODELS BEGIN THE DAY 4 TO 8 PERIOD WITH AN  UPPER-LEVEL LOW OVER THE NRN PLAINS. THE MODELS DEEPEN THE  UPPER-LEVEL LOW AND MOVE A MID-LEVEL JET ACROSS THE SRN AND CNTRL  PLAINS ON MONDAY/DAY 4. IN RESPONSE...STRONG DEEP LAYER SHEAR SHOULD  BE PRESENT ACROSS MUCH OF THE WARM SECTOR SUGGESTING WIDESPREAD  SEVERE STORM DEVELOPMENT WILL BE POSSIBLE. WILL MAINTAIN AN ENHANCED  SEVERE THREAT AREA EXTENDING FROM CNTRL OK NEWD INTO NCNTRL MO FOR  DAY 4. ON TUESDAY/DAY 5...THE MODELS DIVERGE CONCERNING THE  UPPER-LEVEL LOW BUT ARE IN AGREEMENT THAT AN UPPER-LEVEL TROUGH WILL  MOVE ACROSS THE SRN AND CNTRL PLAINS. THUNDERSTORM DEVELOPMENT WILL  BE POSSIBLE AHEAD OF THE UPPER-LEVEL TROUGH FROM THE MID MS VALLEY  SWWD INTO THE SRN PLAINS ON DAY 5. A CHANCE OF SEVERE STORMS WILL  PROBABLY EXIST ALONG THIS CORRIDOR DUE TO MODERATE INSTABILITY AND  SUFFICIENT DEEP LAYER SHEAR WHICH IS FORECAST BY BOTH THE ECMWF AND  GFS. ON WEDNESDAY/DAY 6...THE MODELS MOVE THE SRN PLAINS UPPER-LEVEL  TROUGH QUICKLY EWD ACROSS THE MS VALLEY. ALTHOUGH THE GFS AND ECMWF  DIFFER ON THE SPEED OF THE UPPER-LEVEL TROUGH...IT APPEARS THAT A  POTENTIAL FOR SEVERE THUNDERSTORMS WILL EXIST ACROSS AN EXTENSIVE  AREA STRETCHING FROM THE NERN U.S. SWWD TO THE GULF COAST STATES AND  WWD INTO THE SRN PLAINS. EVEN THOUGH THERE IS POTENTIAL FOR A  WIDESPREAD SEVERE WEATHER FOR BOTH TUESDAY AND  WEDNESDAY...CONFIDENCE REMAINS TOO LOW TO FORECAST AN ENHANCED  SEVERE THREAT AREA.    ..BROYLES.. 05/17/2013

[Jim Marusak]

Most normal indications would say with such large hatched areas on the d2 and d3 outlooks would hint at mod risks of severe at the very least. But given the track record over the past couple of months with mod risk busts and such, I can see the gun-shyness with what they're doing. and honestly, it probably is a better move until we get to the 12z analyses tomorrow. If the 12z RAOBS come out and show conditions close to what the models are currently showing, I see no reason not to escalate to at least moderate risk.

 

But given that this potential outbreak is happening where it is and not closer to the Canadian border, I bet they might have escalated a bit sooner if it were into northern ND, northern MN, UP of MI, northern WI. And the reason why I say that: it's Victoria Day weekend up there this weekend. And while yes that holiday is honoring some stuck-up queen from a while ago, it's actually more like our memorial day in that it's the "Kickoff to Summer" weekend for them. So at least you won't have out-of-town people to deal with, except if there are weather weenies making their way down from the Alberta, Saskatchewan, Manitoba, or Ontario.

[KSWx]

Most normal indications would say with such large hatched areas on the d2 and d3 outlooks would hint at mod risks of severe at the very least. But given the track record over the past couple of months with mod risk busts and such, I can see the gun-shyness with what they're doing. and honestly, it probably is a better move until we get to the 12z analyses tomorrow. If the 12z RAOBS come out and show conditions close to what the models are currently showing, I see no reason not to escalate to at least moderate risk.

 

But given that this potential outbreak is happening where it is and not closer to the Canadian border, I bet they might have escalated a bit sooner if it were into northern ND, northern MN, UP of MI, northern WI. And the reason why I say that: it's Victoria Day weekend up there this weekend. And while yes that holiday is honoring some stuck-up queen from a while ago, it's actually more like our memorial day in that it's the "Kickoff to Summer" weekend for them. So at least you won't have out-of-town people to deal with, except if there are weather weenies making their way down from the Alberta, Saskatchewan, Manitoba, or Ontario.

 

 

Are you thinking the hatched areas will remain that large, or will they shrink as we get a better idea of how it's going to play out?

[blizzardof96]

Incredible GFS sounding for OKC

[Indystorm]

Friday morning NAM continues to show ominous parameters from OKC northeastward on Sunday evening as has been progged.with SPC saying that widespread svr wx could continue eastward through Wed. but they cannot outline a specific area as of yet as Andy noted in SPC reasoning in above post.

[Jim Marusak]

Are you thinking the hatched areas will remain that large, or will they shrink as we get a better idea of how it's going to play out?

I think it'll shrink just a bit, but also be more in tuned tomorrow morning. you have two factors still to deal with. One, the system still making the jump across the rockies. these days the models are better at handling that jump compared to what they used to, but you still have to watch sometimes.

the other factor is that upper-level disturbance (seen really well on this morning's 500hpa chart) that caused the Texas tornadoes 2 nights ago and the tornadoes in Louisiana yesterday. it's moving steadily to the east through southern MO this morning and should eventually kick east towards the central Appalachians this weekend with the trough coming in making for the setup. If that disturbance in any way slows down and sticks back a bit compared to what the models want to do, you may have a problem where the moisture doesn't make it in time because it's being drawn in to the lead upper-level system instead. But just looking at a loop in the analyses, it should kick out in time. but the 12z raobs tomorrow morning will have to confirm that movement to get that disturbance out of the way and get the flow fully open from the gulf for the perfect chasing weather to begin.

[nrgjeff]

While no one day screams high risk or major tornado outbreak, the 3 chasable days in a row qualifies as a must-go. Overnight progs backed off Monday a bit but the NAM/WRF and Euro show a better Saturday forecast (for storm chasers). I was hoping Monday would be better since it's the less crowded weekday, but beggars can't be choosers. Saturday with the herd works. Sunday looks great.

 

Saturday: Models still show an east-west boundary lifting through Kansas on Saturday. Today a differential heating boundary sits along the Red River (OK/TX). Will it really be there tomorrow lifting north? LLJ needs to stay at least somewhat decoupled tonight to avoid boundary mix-out. To avoid this question, along with capping questions, there is always the synoptic WF north.

 

Sunday: NAM/WRF (just in) keeps that CF surge, but 60 hours is still beyond its strength. Toto we ain't in April anymore. It's May! GFS/Euro agree on a more favorable set-up - for storm chasers. Might be worth a MDT when it becomes Day 1 but until then I'd expect high-end hatched slights.

 

Monday: Tricky forecast. Sunday night storms will have an impact on surface features. Models not in total agreement on orientation system either. Northern branch starts stacking up. Southern stream energy forecast in some models still, but it's not screaming like it was yesterday. Even if DL disappoints, there should be outlfow to work with.

 

While details have not fallen into place yet, the multiple day set-up is arguably better than one big day. There are more chances to get it right, vs all the pressure to score in one day. Love the law of averages. Good luck and chase safe!

[Jim Marusak]

agreed, this is definitely chaser potential. but one thing i'd watch in the dakotas, and MN, apparently there are two major refineries down in the Chicago area and our gas prices spiked from 3.80 to 4.20 a gallon yesterday (got to love 2 refineries being down for major maintenance at the same time). so be sure you bring some extra scratch if you're headed towards this area for the tank.

[Bryan Wood]

agreed, this is definitely chaser potential. but one thing i'd watch in the dakotas, and MN, apparently there are two major refineries down in the Chicago area and our gas prices spiked from 3.80 to 4.20 a gallon yesterday (got to love 2 refineries being down for major maintenance at the same time). so be sure you bring some extra scratch if you're headed towards this area for the tank.

Same thing as far south as OK and Southern MO. A couple of refineries are down in KS & OK.

[LocoAko]

Same thing as far south as OK and Southern MO. A couple of refineries are down in KS & OK.

Not to get too off topic - but is that what has caused gas prices to soar here? I normally am not one to complain too much about gas prices, but according to gasbuddy.com the OKC area average is over $0.25 over the national average when normally we are very far under it. It's jumped $0.30 in just the last week.

http://www.OklahomaCityGasPrices.com/retail_price_chart.aspx?city1=OklahomaCity&city2=&city3=&crude=n&tme=1&units=us

I just assumed they were overcharging all the incoming chasers.

[Bryan Wood]

Refinery shut-downs in Tulsa and KS are to blame. Less capacity to refine gas = higher prices. It's what happens to the south when a bunch of refineries shut down due to a Gulf hurricane.

[Jim Marusak]

well, for the chasers, gas cost is a factor in all of this. i know here the prices they say are supposed to be in the 420 or so range (which is like 3rd or 4th highest in the nation) until the 4th of july due to the rockford and chicago refineries doing major maintenance at this time. so if it's the same thing going on down there in Tulsa and KC, then we have to wonder if it's a conspiracy against chasers, much less holiday travelers.

 

but back to the storms. and with my look at the 12z NAM, if the GFS and Canadian regional follows the same thought pattern, a mod risk may eventually be in the offing.

[soonertrey]

 

but back to the storms. and with my look at the 12z NAM, if the GFS and Canadian regional follows the same thought pattern, a mod risk may eventually be in the offing.

 

Based on the 12z NAM what area would you place a MDT? Central OK looks pretty good to me. Northern MO looks to have a veer back veer issue on the latest run.

[Jim Marusak]

d2 mod risk, I'd probably go with a rough outline similar to this.....  and please others feel free to redraw as needed.

 

an area enclosed by the following obs sites: HON > PIR > CDR > MCK > DDC > CNK > JYR > OFK > FSD > ATY

 

slight risk would include central/eastern OK, western MO, western IA, sw MN, w-c MN, northern SD, sw SD, NE Panhandle early, south-central/southeast KS, and maybe north-central texas. but north-central TX and eastern OK i still have some issue about a cap there.