Long Range Forecast

April 3rd (Day 2)

corepuncher — Wed, 02 Apr 2008 04:09:00 +0000

Well, time to dust off the ol' chasercam and chase equipment for a possible bigtime chase! Nice set of features coming together for a relatively confined tornado outbreak, from SW OK into NW TX. Not to get into the details TOO far in advance...nice trough emerging, low level moisture return, heating near the dryline, and great shear profiles should spell a couple strong tornadoes. Will update the chaseday forecast when Wed night or Thur morning.

Stick a fork in it

corepuncher — Sat, 27 May 2006 21:53:00 +0000

Long range models show upper ridge building over the West, and a trough in the East. This is exactly opposite of what we want. I don't forsee anything worth chasing at least for a few weeks. Maybe mid to late June will turn around, but I'm not holding my breath.

FCST: May 27th - May 31st

corepuncher — Tue, 23 May 2006 22:40:00 +0000

Medium range models are showing a ridge building over the ERN CONUS...which will allow better moisture to "stew" across the gulf region. Meanwhile...a mean trough is forecast across the WRN states, with daily lee troughing across the high plains. Given increasing moisture this coming weekend, I'm hopeful for diurnal dryline setups favoring a few supercells. A major key to how productive any one day is will be the amount of mid/upper level flow which will impinge on the dryline from the west. With such a strong ridge building aloft, its hard to get a trough to "plow" EWD through it. GFS shows higher flow across WRN KS/NEB and ERN CO by Tuesday May 30th.

Since I haven't been chasing, what HAVE I been up to? Pulling weeds, cleaning the garage over and over, and making various home improvements. This is not acceptable May behavior.

FCST: Through May 20th

corepuncher — Wed, 10 May 2006 20:30:00 +0000

The pattern looks like crap. Absolutely horrible. Might catch a NW flow storm in the plains every now and again but moisture will be marginal for anything worth chasing given gas prices. See you in a week or so.

FCST: May 2 - May 12th or so

corepuncher — Mon, 01 May 2006 17:56:00 +0000

Long range models have done several "flip flops" as of late, but seem to be hinting that a trough will eventualy set up over the WRN CONUS May 9-12 and maybe beyond. In the near term, Tuesday May 2nd looks like a decent chase day with good visibility and some good strong updrafts given very steep mid level lapse rates and returning moisture, although the NAM/GFS models are WAY overdone with low level moisture...60-63 dewpoints appear likely at peak heating along the dryline, not 65-70! I'll likely chase this day.

Beyond, we're getting to the time of year where it will be easier to get moisture for storms. I do not like this persistent ERN U.S. trouging that keep occurring...makes for narrow warm sectors. If we can get a nice solid trough to swing through the central U.S. with a couple days of moisture return, we'll be in business!

FCST: April 24th

corepuncher — Wed, 19 Apr 2006 11:31:00 +0000

GFS and ECMWF are in very good agreement with timing of moderately strong and progressive shortwave trough emerging into the SRN high plains on Monday (does this necessarily mean the forecast is reliable? I have no idea, but it makes me feel good). The only problem (with regard to a high end event) is that retarded high that moves into the Gulf of Mexico this weekend...giving us only 1 day of decent moisture return prior to the potential chase day. Hey, this is nothing new, after all it's early spring....and...we have been working with sub-par moisture all year long, but that hasn't stopped the tornadoes, has it? Thanks to good ole steep mid to upper level lapse rates, our potential is maximized. GFS soundings (138 hours out at the time of this writing) show 700-500 mb lapse rates over 8.3 c/km and a mid 60 dewpoint! The dew is suspect to me, but nonetheless I will gladly verify this forecast personally by filming a large and long lived tornado.

FCST: Through mid/late April

corepuncher — Wed, 12 Apr 2006 18:54:00 +0000

Doesn't look good at all for chase opportunities in the long range. In the short term, there is a trough coming out on April 15th across the central and nrn plains, but moisture quality will not be good. Can't trust the models exact location this far out but it appears from NERN KS into ERN NEB and WRN IA will be the spots to be (not me though).

After this wave moves through, looks like that nasty ERN U.S. trough will want to re-emerge. We can spare 2 or 3 weeks here in mid to late April, as long as May turns around! I suspect we'll see another round of troughs by that time, at which time the smorgasbord will become fully stocked.

FCST: Thursday April 6th

corepuncher — Tue, 04 Apr 2006 02:15:00 +0000

Active early spring pattern continues with another powerful system coming into the plains on Thursday. Main concerns for chasing at this point are moisture quality and instability, along with very fast storm motions. As we saw on March 12th (a day I was under 2 separate mesos), in these situations you typically have one chance at a storm as it passes. Exactly where you decide to do your "toro!" is key...you really want to see the storm at peak intensity. In the case of the second storm I was on March 12th, had I chose my spot one county to the NE, I would have seen a strong tornado.

Models are in good agreement as far as timing of this trough, and the new 00Z 4/4 NAM has changed for the better it would seem. The trough over the E is not as far south, which will help moisture return a tad. And, the dryline is farther W than previously progged, now over ERN KS/OK at 00Z Friday instead of way far E into wrn MO. NAM is still holding near 60 surface dewpoints all the way up into Nebraska and SWRN IA, which when combined with very cold temps aloft creates some decent instability with MLCAPE of around 1800 according to forecast soundings. Keep in mine moisture "depth" may not be great, and if it mixes out, which it probably will, we will be left with upper 50s dewpoints. However, that's no different than March 12th and you know what happened that day. The key is keeping steep low to mid level lapse rates, for example 700-500 mb. I like to say, "Lapse rates over 8, tornadoes will be great", referring to 7-5 lapse rates over 8 c/km. Anyhow, I will likely chase Thursday.

Long Range Forecast: March 29th through April 2nd

corepuncher — Mon, 27 Mar 2006 01:27:00 +0000

Things will be heating up in the coming weeks and it could prove to be a busy start to the month of April...something we have not experienced for quite some time!

After this trough over the Eastern states lifts out, the models are forecasting upper ridging to materialize over the same area...this is good for us as it allows pressures to lower across this region...letting air of carribean / gulf origin to advect NWWD across the gulf.

All long range models are in agreement early on, kicking off this potentially active period with a possible chase day on Wed March 30th. At this time, it appears moisture return will be in its infancy, thus instability levels will not be very good. However, some upper height falls aloft with approaching trough (axis back over AZ 00Z/30th) and heating may allow for isolated thunderstorms along the dryline from WRN KS into WRN OK and NWRN TX. Don't hang your hat on anything GOOD, just know there may be storms. I'm at least OFF work this day, but doesn't look too good.

The next day, Thursday, looks much better for widespread severe as the trough kicks out into the plains while deepening. By Thursday, surface dewpoints, I suspect, will be in the lower 60s as far North as SERN KS and WRN MO...with mid 60's down across AR into TX. Very strong wind shear will exist with this system, but as always this time of year, instability will be in question. Also, storm motions will likely be out of this world fast so I'm not that excited...although it could be similar to March 12th in many ways. I have to work so I really don't care, however (it will be fun to work though).

As always I have my eyes set on the future...when at some point, we will have mid to upper 60s dewpoints up through OK, KS , TX panhandle, with a nice broad belt of flow coming out, along with very steep mid to upper level lapse rates. Models say...this might occur as soon as Monday April 2nd. The ECMWF has a really nice amplitude to the trough while the GFS is less...but regardless..there will be instability in place. I actually prefer the lower amplitude system because there will be less clouds and storms covering the warm sector, and less risk of early/premature development. Fingers crossed...GFS shows 3500 CAPE along with nice hodographs with 25kt ELY storm motions! I have to work that evening at 8pm...maybe I can squeeze in a few hours of chasing if it is a local event. Anyway, that is 174 hours out as of this writing, and much can and will change. We'll keep you advised.

Forecast: March 19-21

corepuncher — Tue, 14 Mar 2006 21:14:00 +0000

Medium range models show some potential down the road sometime between next Sunday and Tuesday.

High pressure is currently sitting over the srn plains and lower ms valley...but the pattern will remain rather progressive...and this high will shift quickly EWD. An upper shortwave trough now over CA will move into the central plains on Wed, and will induce low pressure to form over ERN CO and WRN KS. With surface high over AL/GA by this time...ELY flow around srn periphery will allow for some low level moisture / dewpoints in the 50s / to return WWD into central and SRN TX by Wed afternoon. Now, I don't expect any severe weather on Wed, but the key is that this lead shortwave will begin to veer low level flow across the gulf, allowing for better moisture return for the next trough.

GFS and ECMWF solutions are similar amplifying an upper trough over the SWRN states on Saturday 3/18. By this time, dewpoints into the lower 60s should cover much of SRN TX...perhaps even as far West as Midland, TX given deep ELY flow. Given favorable shear profiles and increased instability, a few supercells would be possible near Del Rio TX NWWD up toward San Angelo and Midland. I probably wouldn't chase Saturday, given long distance and marginal potential at this time.

The better day, according to the models, would be Sunday March 19th. There are some timing issues of course with speed of upper trough...ECMWF has the trough axis over the lower CO river valley , while the GFS brings it into ERN AZ by 12Z Sunday. Either way, there will be better moisture in place for instability with dewpoints into the 60-65 degree range likely given persistent SELY flow. Details are impossible to hash out this far out (120 hours), but models suggest a warm front near the Red River, and favorable shear throughout the warm sector for supercells. Will continue to monitor!

Forecast March 7 - 8

corepuncher — Mon, 06 Mar 2006 16:53:00 +0000

- Tuesday, March 7th -
A fair shot at supercells across much of WRN OK. Of course, I have to work until 8pm so no chase for me.

Upper ridge axis will shift EWD during the day...allowing 50-60 kt mid level flow as well as cooler temperatures aloft to overspread the area. At the surface, upper 55-60 degree dewpoints will return NWD out of TX. This will not be high quality moisture, but good enough given decent mid level lapse rates. Subsidence and drying forecast over central TX and these lower dewpoints will likely move NWD into SRN OK by late afternoon. The real problem may be mid and high levels clouds which will hamper heating. This COULD keep a lid on things until near sunset when LLJ increases. Still, there is a good chance of at least an isolated supercell over WRN OK before it gets dark....could even be two! This is a "NO COREPUNCHING" kind of day, as parameters will be favorable for Significant Hail (> 2" diameter) IF dewpoints are near 60F! Watch out for those falling baseballs, and good luck.

- Wednesday March 8th -
I may actually be able to chase this day, since I get off work at 4 pm. Upper trough will continue to overspread the area...with lots of large scale lift / cooling aloft. Persistent SLY flow in the warm sector will remove any "dry holes" that appear over TX on TUE with dewpoints into the lower 60s E of the dryline, which will be near I-35 late afternoon. Triple point intersection should be near Wichita KS late afternoon, which will be likely initiation zone for surface based supercell formation. More cells should develop SWD along dryline. It will be VERY COLD ALOFT thus expect a few Sig. stones. I also expect a few tornadoes, mainly over SERN KS and NERN OK. Shear profiles are very strong, only trouble is storms will be moving quickly NEWD around 45 mph. That's enough for a day 3 forecast...more tomorrow.

Forecast: 3/4

corepuncher — Fri, 03 Mar 2006 04:50:00 +0000

Amazing! My 5 day forecast might verify. I'm not giving myself any credit for this, I'm just surprised that the latest NAM actually shows some potential for Day 2 and that the long range models were basically right.

First off I'll say I cannot chase Saturday, I have to work (filling in for someone...boo!). I would like an opportunity to try out my new ChaseCam. I get off at 4pm so there is a SLIGHT possibility of me testing it out but 22Z is pretty late for this time of year and I don't think this event will go much past sunset, if it even "goes".

Short: I'm forecasting isolated storms to form on the dryline late afternoon where it really heats up. There is the potential for a supercell or two, from SW KS into far WRN OK and TX panhandle. The main severe threat with these storms will be hail, maximum size around Golfball (1.75").

Long: As of this writing, a big nasty surface high (ridge) currently cover much of the central plains. This high really won't start moving out until late in the day Saturday, giving only 24 hours for moisture to return. Thus I don't expect dewpoints to be much above 55 where the storms initiate. Forcing for convection will not be strong, but it will be there with upper trough making glancing blow to the area. Judging from forecast soundings, the key will be the heat. We need heat to get these storms going. That being said, I see surface based parcels of 75-80 temp. with 50-55 dewpoints. This is fine for supercells given favorable wind profiles, but not good for tornadoes. Any storms that do develop will likely produce some hail. Thinking about corepunching? Think again. I expect some golfball sized hail with the strongest storms, perfect progging this of course!

Forecast: March 4th and thereafter

corepuncher — Tue, 28 Feb 2006 04:45:00 +0000

With no frontal intrusions forecast for several days, moisture will begin coming back in earnest on Friday 3/3 with mid 60s dewpoints into south central TX by SAT morning. Unfortunately, and not too surprising is that the GFS model has come in line with the ECMWF and now dampens out the amplitude of the trough forecast to move across the plains on March 4th, with upper ridging actually forecast over OK/TX as the wave pushes NE! Thus it appears that all we SRN plains folk can expect on Saturday is a nice round of warm advection thunderstorms. Hey I'm not going to complain, we need the rain! And, the mid troposphere is cool enough that we might even see some elevated severe hail. But don't' be fooled by the seemingly favorable CAPE and shear parameters along the dryline Saturday afternoon...the 850 flow will be veered due to slight upper ridging and without strong heating and quality moisture in place, typically deep convection fails to initiate in these weak forcing situations. Anyway, that assumes the trough moves too far north to influence the unstable area...this could change!

After this trough lifts out of memory, the models carve out a gigantic trough over the ERN CONUS. This is not good as it only bring high pressure swd through the midwest. All hope is not lost however, as the overall pattern looks to remain active with multiple troughs and ridges shifting about. If you are interested, here are a couple links to check out some models:

http://www.rap.ucar.edu/weather/model/index.php?model=gfs
http://meteocentre.com/models/ecmwf_amer_12/cep12_9panel.gif
http://weather.cod.edu/forecast/

Forecast: 2/28 - 3/6

corepuncher — Sun, 26 Feb 2006 05:26:00 +0000

Latest long range models are showing some early season chase potential across the srn plains with periodic troughs over the WRN CONUS. GFS is most bullish showing main trough coming out across the plains on 3/4...while the ECMWF dampens the trough out drastically with only slight swly flow aloft for the same day. If the GFS verifies, forecast soundings support supercells, possibly tornadic, across OK/KS. If the ECWMF verifies...we might have to wait a while until the next trough comes out later in the period 3/11-3/12 or so. Regardless, it looks like potential is increasing for some severe storms somewhere across the central or srn plains during the period...with all models shifting toward more of a "troughy" pattern out west.

The chase season is rapidly approaching, make sure you are not caught off guard!

Forecast: 2/20 - 2/27

corepuncher — Mon, 20 Feb 2006 21:26:00 +0000

The pattern will remain unfavorable for severe thunderstorms over the CONUS.

ECMWF and GFS models are in good agreement through the period with a continued confluence of nwly nrn stream and zonal/wly srn stream jets. Generally zonal flow across the SE will allow for weak low level warm advection across the Gulf Coast and into central TX, bringing lower 60's dewpoints ashore. Residence time of these dewpoints will be short however, as a NRN stream disturbance amplifies across the upper MS valley and another arctic front pushes swd through the plains. Models amplify this disturbance into a longwave trough through the weekend along the E coast. Thereafter, it appears the propensity of the atmosphere to dig troughs SEWD into the ERN CONUS will continue.