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.


Allenspark Lodge said...

Wow- I'm so sorry. You look forward to a vacation all year and BAM! The weather doesn't cooperate (though in your case it's kind of bass-ackwards from what the rest of us would hope for). Maybe you could review some fast food joints on your blog...


Jason Persoff, MD (the StormDoctor) said...

Thanks, Bill...It's the nature of the beast. Still surprising to me.