Sunday, May 24, 2009

Abbreviation of the Chase...Getting Back to What's Important

Today I've hit a sort of critical mass, one that requires I refocus my efforts on my family and take the time I have remaining in my vacation to be with them. I love chasing, but I love my family more. I just don't get enough time off to spend with them. For any number of reasons, they're feeling my absence more this year, and I am really needing to be with them too. Heading home one week early from the Plains allows me to acknowledge that this year's chasing prospects are nothing but recurring marginal days with hours of driving and a lot of expense with only a lonely heart away from my family--my wife and kids. I choose to be with them. Financially, emotionally, and intellectually, I know this to be right. There will always be "next year" for chasing. My real life beckons, and I will yield to its lovely siren song.

Saturday, May 23, 2009

Unexpected Chase: Saturday, May 23, 2009

///UPDATED 5.23.09 @ 2130
Terrifically fun little chase day (<150 miles round trip). Early initiation along a boundary mentioned below led to briefly rotating LP storms that sadly congealed rapidly into multicell squall lines. I did take a few photos today, but as I work on them in the digital drylab, I continue to be a bit disappointed with the quality. There's not a lot of cool dynamic interaction between the sky and the land, and the colors are bleachy. Still, I made it home before dinner and under a tank of gas. Believe me that I'm not sated. But some of the pain of the year washed off just by getting to feel like a chaser again for a little while over chase terrain on which I'd cut my chasing teeth in the 1990s.

Totally unexpected day...I'm on home chase territory and agree we're in landspout mode. Starting in DEN and heading along I-70 to the DCVZ. Confluent wind fields N/S along the Palmer Divide have set up nicely. T/Td spreads are very small for this area, and in fact there is more humidity than I could have hoped for (Tds are 50+). All of this is about initiation and catching the early landspout. I can't be too picky. But I'm liking the current mesoanalysis. Off to I-70.

Again, you can follow my progress by looking at the car-shaped icon in the map below.

Thursday, May 21, 2009

Chase Forecast for Monday, May 25, 2009

///UPDATE 5.24.09 @ 0845
I keep looking at the latest NAM, and it seems as if the dryline will be pretty fairly crisp (50+ ahead, <30 behind) over a very narrow corridor along the NM/TX borders on Monday. A hint of a buldge evolving over the subsequent days may act as focus over LBB-Midland, but likely won't be a player for tomorrow.

Upper level winds look more favorable than before. But the damnable upper level GOM low is screwing up the meatier juice we needed from the GOM and so Gulf moisture will take a pretty far detour east and then north before turning toward the Plains. That's going to hurt our storms a bit, that overall lack of midlevel moisture.

Rotational shear shouldn't be a problem, but speeds AGL for all levels have about the same magnitude without any really good speed acceleration with height.

So far, this spells HP bombs of very short duration, mostly multicellular, and with possibly pretty structure early on from a distance.

Why does this year feel so damned hard to forecast?

///UPDATE 5.22.09 @ 1330
Geez...Looking at the GFS and NAM, it's as if someone sprayed jetstream repellant over the whole of the US Plains. Just north and south of the US borders there are jets. That they are mirror opposites in their wave phase only adds to the feeling that the jetstreams are trying hard to avoid touching the US.

So, Monday...The GFS and the NAM are both showing the same gist.

At the surface a sharply delineated dryline will set up over the Cap Rock area, with Tds in advance of the line >55 deg. The dryline will develop a bit of a bulge around the AMA area. Sfc temps could near 100 deg. A low is forecast to form over NM and push out into the TX PH. Upper level divergent flow regime will be aided by an upper low pressure system over Baja. But that "aid" is merely to add a touch of buoyancy to an awful flow with 200mb winds barely exceeding 30kts out of the WSW and some "impulse-ish" 35kt WNW flow at 500mb. There will be rotational shear with height, but it's not a nice looking hodograph over the LBB to AMA area (sfc ESE at 10+, 850mb SSE, 700mb WNW, 500mb WNW, 200mb WSW). There won't be a lot of CAPE (AOA 1000 J/Kg). Tc should be surmountable from daytime heating, a lack of cloud cover, and the dryline. UVV forecast to be good, but mixing ratios are absolutely dismal.

It's hard for me to look at this forecast and feel enthusiasm. Current models suggest this is almost too borderline even to hope for Caprock magic. I sit flabbergasted at the year that isn't. When I saw that the 4-8 day outlook was a mere 3 sentences this morning, I bowed my head in mourning.

I've already began to explore the costs of changing my reservation to fly back to FL and turn in my car rental a week early. It's a good cost-saving maneuver given the situation...I laugh a bit: thus far this year, I've shot a total of 2 pictures and 30secs of pea-sized hail video. That's it.

///ORIGINAL POST 05.21.09 @ 1300
I have absolutely no correlary to this year in my nearly 2 decades chasing. None at all. I cannot remember anytime I've ever seen such an incredibly dead end-of-May. While I've joked with my chase partners, Bill Hark and Robert Balogh, that I can still live and breathe the storms from last year in my memory, and that that somehow that would carry me over through a potentially dead pattern, I am nevertheless shocked at how unfavorable everything has become.

I thought '05 and '06 were awful, but '09 is easily the worst in memory. I'm still scheduled to fly out of DEN on 5/31. But for the first time ever, I'm considering the costs of flying home early. Hell--Bill Hark isn't even out chasing with me this year (also a first).

Everything is so out of phase, that ingredients for svr are separated by over 1000 miles. It's as if someone sprinkled the northern hemisphere with the components, and they fell randomly where they may. Rare disturbances appear over the PAC right now, but none of them look like huge impulses that will bolster systems beyond brief buoyancy enhancements. While the airmass over the Plains has a shot at gathering some flow from MX and moistening some, only brief bubbles of Tds >50 are forecast here and there in OK or ArkLaTex areas.

The GFS 12z run this am is showing a tightening dryline in the TX PH around Tues 00z, coinciding with a low pressure system in that same area. But the moisture there will be quite shallow and the 500mb winds will struggle to achieve speeds >20kts. Perhaps the only upper level joy that will exist is that the winds in the upper levels will be divergent over this area owing to ejection from an upper level low over Baja. Convective temps are going to need to be hot with 700mb temps in excess of 10deg in this region, but this shouldn't be too much of an issue given temps in excess of 90 deg forecast in Midland. A dot of convective precip breaks out over the NE NM/TX & OK PH region after 00z.

So, I'll keep monitoring that area and won't bag the entire season just yet. But even I am pessimistic and deflated. It's tough looking down the barrell of 12 more months before I can be back out here chasing again. So for now I'll take a couple of days just to chill out and get some non-chasing work done.

Tuesday, May 19, 2009

Chase Forecast for Wednesday, May 20, 2009

///UPDATE 5.20.09 @ 2030
Wow...and that's that. Pea size hail and some rain. That was all. No good structure except a small rear-flank hail core. Cells just never got their stuff together. Thus far, the tally for me this year is: zero TOR watches, zero SVR watches, zero TOR warnings, and zero SVR warnings. No severe weather at all. Next prospects for anything don't appear likely until the weekend, and even more realistically next week. I'm just flabbergasted.

///UPDATE 5.20.09 @ 1417
SPC issues an MCD for this area and storms pushing out of WY are now taking on a better radar appearance. Any move to the north is now on hold.

///UPDATE 5.20.09 @ 1400
Early afternoon ambivalence...

The LCLs appear much better (about 500ft lower) in SD in the area and CIN appears to be wearing off in that area. Satellite suggests that the convergent field in that area is isolated, but looks pretty clumped like a cluster, and that worries me a bit.

I'm not thrilled with the stuff pushing off of the SE WY area either. The LCLs are very high there and they have a pretty linear appearance to them. The best Td in the region looks to be Chadron which is reporting 73/50. N and S of there Tds are very low (in the 30s).

So I'm going to go to Hemingford, NE, at the moment. This seems to offer the lowest tradeoffs, but still with some hopes.

And I was way wrong earlier about the winds not backing. They definitely are rotating to the SSE just S of I-80. Also, a mesolow has evolved on mesoanalysis right at the junction between SD/WY/NE PH. That settles the need to push north from Bridgeport, NE, where I'm writing this.

///UPDATE 5.20.09 @ 1130
Geeez...I'm in Ogallala now, planning on zipping up US26 toward Bridgeport, NE. In fact, I laughed when I saw that the new Spotternet location (which is pretty slick) locates me at the moment "1 mile south of L and L trailer park". I was unaware that that was a new geographic destination.

The winds here are almost out of the west, and the current mesoanalysis shows that Tds have just plummeted across the NE PH. 3hr Td change is highest over the Badlands NP. All indications thus far show that most convergence will be on the back end of the cold front where WNW winds will abut the westerly winds here.

I am increasingly inclined toward Alliance, but will reassess in Bridgeport. Still posting in FCST thread because we're still hours away from any nowcasting. A bit disheartening seeing the day playing out even drier than I'd expected.

///UPDATE 5.20.09 @ 0800
Chase day...

Today feels a lot like watching a waiter who's stacked the cups too high, and they're just slightly askew, beginning to tilt over. Will he make it or won't he? And that is how the vertical look at the atmosphere this am appears: out of synch, delicate, almost too fragile for something good to happen.

My surface analysis reflects this. The best CAPE is well south of the best upper level support. Worse, the air is forecast to dry out at all levels substantially as the T/Td depressions intensify.

I can only hope at this point that the upper level impulse will somehow combine with the other meager ingredients to give up some okay cells over beautiful chase terrain. I'm going to remain in N Platte for now, though expect I'll be heading north toward Valentine, NE, as the day progresses.

///UPDATE 5.19.09 @ 2000
12z NAM continues to focus a dry punch along the Sand Hills (along the NE/SD borders) Thurs 00z. I'm inclined to believe the progs given the amazing southerly winds blowing across I-80 today transporting the thin moisture up to this area. Upper level support, naturally, is much further north, but a shortwave should rotate through by tomorrow afternoon/evening. I'm hoping the winds to respond a little more than they're progged at the surface. If we can get any backing with the upslope, tomorrow actually could be a diamond in the rough. I'm counting on it; even a single photogenic storm would be rapturous.

So I've pulled into North Platte and look forward to pulling out pen & paper in the morning. Tomorrow, the chase is on.
So, I've decided to stay in leisurely mode, and won't be attempting MT or SD today (5/19) as I'm in Lincoln, NE, and that's way too much of a stretch. So my focus will be on tomorrow. Initially I was going to continue my drive straight to Denver, but today will be a leisurely roll toward the NE/CO border for tomorrow's potential convection.

Current target is North Platte, NE.

At the surface, the cold front will meander SE-ward and will be in a NE/SW orientation from CO up to E SD. A dry punch appears pretty well demarcated in W KS with Td's in advance of the intrusion a mere 45-50 (though that's more than enough in the CO/WY/NE area). Sfc winds will be a touch problematic as they'll be out of the SSW, and risk running more or less parallel to the front. But, if the forecast low in NE CO can tighten up a bit, we may see some backing winds in response. T/Td spreads are on the order of 30-40 deg if the highs verify, meaning very high based storms. These still can be photographic treats, and may offer good, highly visible lightning shots. And in this regime, that's a lot.

CAPE will be in ample supply...if we were in FL. But in the Plains it will be CIN vs. CAPE in a duel of the air parcels. Assuming we hit the Tc, we should see CIN erode sufficiently and hopefully capped enough to allow only a few cells to poke up (instead of MC clusters). The 700mb temps are summer-warm (at or above 10 deg).

As a disturbance pushes across the region, there is hope of a teeny jet streak at 250mb (W around 50 kt) with a stretch-of-the-imagination entry region at 500mb (W winds only around 20-30 kt there). 800mb winds are out of the SE.

So, using my IF-casting model. If the cap can be overcome by the front and daytime heating, if the parcels can keep it together enough to become organized, if the sfc winds back more, etc., than iffy conditions will spell some beautiful single cell high-based storms. If we're luckier, they'll situate the selves over some good looking shrubbery (sufficient to make the Knights Who Say Ni proud), and we'll get photographic storms.

In this pattern, it's really all I could hope for. It's enough for me to be heading to N Platte today.

Again, you can follow my progress by looking at the car-shaped icon in the map below.

Monday, May 18, 2009

On A Lighter Note...

Well, it's supposed to be storm chasing season, but for now it's only driving with sunglasses on :). Still, I'll try to post my forecasts and various rants as I drive along. You can follow me via the following Flash widget (pretty cool). I'll eventually set-up the webcam when there's something to see. There appears to be an issue right now with the data flowing properly onto the map below, but when it's working, I'll appear as a little car icon.