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vortex95

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  • Four Letter Airport Code For Weather Obs (Such as KDCA)
    KDCA
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    MD

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  1. vortex95
    RRFS valid 21z Tue looks promising. Quite strong 500 trof for this time of year. Solid jet dynamics appear likely so supercells. Now, tor potential, that's an entirely different story and we'll have to wait until much closer to the event for things to become clear.
  2. vortex95
    I don't know if the RRFS can handle TCs properly. This is a good question for the modelers. The NAM never was designed for TCs we know. The RRFS seems overdone, esp. given by 72 hr a strong deformation shear zone get established along the nrn Gulf Coast, and the system gets torn apart aloft. The HRRR through 48 hr does show it becoming a TD, but again, I am not sure how good mesoscale models not specifically designed for TCs, such as the HAFS and HWRF, do here. The 2m wind field looks choppy and pock-marked on the HRRR by 36 hr. The HWRF from 18z today shows sig development having is 992 mb by 60 hr, but that appears overdone. GFS/ECMWF suggest weak TD status before the environment becomes unfavorable.
  3. vortex95
    That is an exceptional amount of CAPE (nearly 6000) for a location on the East Coast. I am surprised there were not more svr hail reports. Low-level shear is weak. 0-6 km shear 37 kt so there is your supercell support. I think the storm coverage was a bit too much and that is what precluded more sig svr wx overall. A bit stronger capping probably would gone a long way.
  4. vortex95
    You had this left mover (anticyclonic supercell) near Manassas earlier. You do not even have to look at the velocity to know this. The storm is deviating to the left of the mean flow and it has the flared NW to SE structure w/ the anvil streaming to the SE despite the storm moving NE! When storms rotate, it becomes complex as to the total motion vectors acting on the storm. Anticyclonic supercells rarely produce tors (in the NHEMI), but giant hail and microbursts are just as likely as w/ cyclonic supercells
  5. vortex95
    More days than not when svr wx occurs and it is favorable for supercells, deep layer (0-6 km) shear is good/great, but low-level (0-1 km) is weak. So you can get intense supercells w/ a nasty mesocyclone at mid-levels, but no real signature for rotation or a TDS at low-levels, and thus no tors. I've seen storms like this before in the Plains, You'd think there would be at least be an organized wall cloud for such an intense mesocyclone aloft, but just ragged, disorganized scud. Yet the storm is dumping giant hail and has incredible structure! A rule of thumb I look at for a basic start for a decent tor day is winds at least 30 kt at 925 mb. That gets you you low-level speed shear, which is important. Next, is there any veering of the winds sfc to 850? Low-level directional shear is paramount, esp.for sig tors. Is there a warm front involved? We are taught the cold fronts are the big tstm producers, and they are, but some of best intense tornadic supercells are those that form on or very close to a warm front, and ride along it. Winds locally are backed at the sfc just ahead of a warm front, but veer quicky aloft, so localized shear/helicity can be much higher than the environmental shear/helicity. Typically in most supercells, the mesocyclone (lowest pressure), is at mid-levels, the if conditions are right, the low-levels can organize for solid rotation. The exception is for TC environments. Supercells are often very low-topped, (might not even be 15,000 ft!), and deep layer shear (0-6 km) is not that great, but low-level shear (0-1 km) is excellent,owing to the strongest winds in a TC often found 925 mb to just a few 100 ft above the sfc. So you can get tors in swarms (look at what the remains of Ivan did in VA in Sep 2004), but most are weak, even a higher percentage from their continental counterparts b/c you don't have much CAPE in a TC environment, so updraft acceleration typically can't support strong/intense tors.
  6. vortex95
    And memorable is relative and location specific. Short distances when it comes to tstms can be huge. Ever happen to get a storm that just maxes out over your location w/ crazy CGs so close and relentless for like 5 min, and you are ducking for cover even indoors b/c the thunder so atypically loud and you are literally hearing electrical click/pops before or during every strike? And then after it is like, "whoa, best ever!" But is a very localized experience, esp. when it comes to close lightning strikes and how loud the thunder is. Still, when it happens, it is awesome! Gets the adrenaline pumping! I can never get enough of such experiences. Give me tons of LTG!
  7. vortex95
    Storm coverage was better than fcst than either the HRRR or RRFS had ydy. Some supercell structures as well, but they had tough time sustaining for very long. Looking at the radar loop, things got messy very quickly w/ storms moving in various directions due to outflow and rotation, colliding w/ each other. This probably limited the svr wx b/c no one storm could sustain for long, so we got a lot of pulse svr storms, despite the decent wind shear and a lot of CAPE. Maybe if the smoke hung around thicker longer, that would have meant less storms, but any storm would have had a better chance to sustain and rotate? The balance when it comes to the mesoscale is tricky. Small differences can be huge as to storm mode, coverage, and severity, often you don't know it until it is happening. This unknown factor has it appeal. We are still "surprised" at times (June 5, 2024 being among the best recent example), and things can look exactly alike on paper for a setup on two days, but what actually happens as to sensible wx can be a lot different. You still get tstms and svr wx, but it goes far beyond that. Will the storms train/backbuild? How intense (frequency) will the CGs be? (that varies a lot it seems). Discrete cells, a SQLN, or clusters? And who exactly will get crushed? So localized in many cases!
  8. vortex95
    I attached the VIS image at 1716z (13:15 EDT on the image is 1:15pm EDT, right?) Was this CG verified? Sometimes isolated strikes are misplotted when there is a lot of activity. No anvil overhead or close to Damascus, but +CGs has been known shoot out laterally up to 10 mi from a CB. And when a storm, esp. a supercell, has a thick anvil streaming well downwind (can be well over 100 mi when winds aloft are strong), you can get CGs out of the anvil 50+ miles away. Farthest I have seen reported and verified is 90 mi from the parent cell core out of the anvil (storms near Enid OK and in strikes far NW OKC)!
  9. vortex95
    Probably +CGs and the thunder was enhanced by the nocturnal inversion!
  10. vortex95
    GFS MOS had 93-94 and it got to 93 at DCA. And the GFS does not have smoke integrated into it, so apparent the smoke was not a factor for heating. The Td got to 77 and DCA and IAD. You get more bang for you buck per deg for Td than T when it comes to increasing CAPE. There is a sig difference between say 72 Td and 77 since moisture increase is not linear, and it really goes up fast once in the 70s!
  11. vortex95
    That's quite good for 12z, esp. the CAPE!
  12. vortex95
    If you are confused, you are not alone. While I understand what SPC is trying to do here (quantify risk better), it not easy or always intuitive (probabilities and statistics are are tough subject for many, or kind of dry)! If mets and wx enthusiasts have problems figuring this out this, forget it as to the general public! It somewhat reminds me of interpreting the homograph, it not intuitive at first you have to spend time on what you are looking at and think in 3-D despite looking at a 2-D plot!
  13. vortex95
    Good to know. Thanks!
  14. vortex95
    Highest gust on record for the summer set in July 1996, correct? They had PL at the time IIRC. And I think this same storm system resulted in record flooding in Quebec.
  15. vortex95
    Coldest I could find outside mtn location in New England is 47 at Fox Brook ME.
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