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andyhb

Meteorologist
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Posts posted by andyhb

  1. The next 7-10 days aren't looking too promising, at least anywhere in the Plains. The fat lady may have been warming up as the June 4-6 sequence concluded and we didn't even know it at the time.

     

    After an exceptionally active April-May pattern wise, it's not too surprising. That said, it is still June, and there will still be tornadoes on various days. And "real" setups can't be ruled out north of I-80 even heading into late June and July.

     

    Yeah that whole idea fell apart fast. Looks as if we'll go all of Spring and June without a high risk or PDS watch at this juncture.

  2. Just a few thoughts about the 00z guidance (focusing on the operationals):

     

    There are two camps in this set of model runs. One, consisting of the Euro and GGEM, is more progressive with the closed low that breaks off the main northern jet branch in the NW in a couple days (this is mainly due to it not retrograding west as far) and eventually leads to a rather messy, disjointed troughing across the N tier of the CONUS late next week since the aforementioned low does not phase very well with the incoming southern stream that undercuts the Aleutian ridging.

     

    The other, potentially more volatile scenario is shown by the GFS and likely an extrapolated UK. These two model retrograde the closed low far enough so that it is not picked up by the northern stream for a slightly longer period of time (both in a similar position at 144 hours). It then (on the GFS) is picked up by the northern stream afterwards and phases with the southern branch more effectively, eventually leading to a very potent shortwave trough ejecting across the Northern Plains around D8-9 with some extremely impressive wind fields for June (and likely higher end severe potential as it seems a large reservoir of seasonably high instability will be in place for whatever does come down the chute then).

     

    In conclusion, while it seems all guidance would indicate at least some severe possibilities late next week (as they have for several days now), it's going to be crucial to monitor the evolution of this closed low off the West Coast over the next few days as it could have major implications downstream for the northern CONUS. Should also add that the northern stream shortwaves that eventually lead to the closed low being picked up are also highly important. Overall, a lot of moving parts and it should be awhile before anything is settled on.

  3. What I seem to be seeing on the recent ensemble guidance is a tendency to shift high latitude ridging eastward over central Canada past the first week of June. Should this happen, it would likely open up an opportunity for the Aleutian low to slide east and allow a relatively open path for its associated jet to the West Coast (with an accordingly active pattern downstream).

  4. With the amazing ET this year, all we need is one or two decent (even subtle) troughs the rest of the spring without the overwhelming STJ influence, and periods comparable to late-season 2004 or 2010 should be easily within reach. It will be a crying shame if the grungefest setups continue unabated through May and June, but still better than some recent years.

     

    We still haven't had that bigger event/outbreak to accent the season yet. There will likely be moisture in spades, just a question on whether the Pacific cooperates. A northern shift will help with the EML situation, with more favorable 700 mb trajectories.

  5. Well, the 00z Euro looks pretty similar to 12z at first glance through most of the fields. H85 temps/winds in particular are almost identical to the 12z run at 00z 5/17. Will get a look at the morning convection/EML situation a bit later. The 12z run did have widespread favorable thermodynamic profiles across a large chunk of the warm sector at 18z, 00z was partially contaminated by convection (not from the morning).

  6. Major morning convection on the 00z GFS for both Fri and Sat, and the STJ is still carving across N Mexico into TX. I'm certainly taking model QPF at face value this time and assuming an outcome substantially less than the ceiling suggested by H5, rather than falling for the "holy crap, that trough in mid-May without drought concerns can do no wrong" voodoo I did last week. This is the second trough in a row that looks like a borderline-inevitable outbreak at this time of year, and better than most anything we've seen late season since 2010-2011... but this is no ordinary season.

     

    Now, obviously, there will still be some tornadoes (at least Saturday), just as there were every day last week.

     

    Will probably start a dedicated thread to this tonight, but yeah the 18z/00z GFS runs would certainly not have too high of a ceiling. The 12z Euro would be very volatile though, whether that goes towards the GFS tonight is the question. The 00z UK is in, although I can't see any of the wind fields on it for that timeframe so that's a bit of a mystery of what everything actually looks like.

     

    I'll also add that the hits seem to keep on coming with repeated western troughing on most ensemble guidance/etc. I'd have to think that something bad (or good, for chasers) is going to happen (in spite of the 5 fatalities over the weekend) one of these times if this type of pattern continues. That's not to mention all of the flooding.

  7. Since the ECMWF did not close it off too substantially at 96 hours, does that suggest that it has an edge over the GFS within that range, especially given the ECMWF's usual tendency to cut off lows too much/early?

     

    Would be best to wait until we get better sampling. The upgraded GFS hasn't necessarily been stellar recently, nor has the Euro at times. I agree that the 12z Euro would have some pretty nasty potential, if we see a consolidation towards its solution, people in the Plains (over a large area) better be paying attention.

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