weatherwiz Posted August 25, 2020 Share Posted August 25, 2020 Finally...we've been waiting all summer for this but the potential exists on Thursday for a widespread...perhaps severe weather outbreak with widespread damaging winds and perhaps some tornadoes all possible. This is a rather delicate setup, however, all the ingredients are there. as always with this type of potential there are numerous caveats and the extent of the potential probably won't be known until early Thursday morning. 1) Morning MCS - there likely will be an ongoing MCS to begin the day (riding along an instability gradient). This will certainly be one feature which complicates the forecast as we would ave to deal with cloud debris and likely subsidence behind the departing MCS. Subsidence can be good as it can help clear junk out faster, however, if it is too strong it can inhibit development later on. 2) Lack of EML/steep lapse rates. lapse rates aren't horrific, but these setups tend to have their severe weather potential (magnitude) vastly increased when there is an EML involved. With that said, combination of temperatures well into the 80's...perhaps near 90 in spots and dewpoints perhaps into the 70's with high mixing ratios should contribute to near moderate instability (again...cloud debris will be a player here too). 3) Rather strong shortwave approaching will be accompanied by anomalously strong mid-level flow with a west-to-northwest MLJ exceeding 50-60 knots with a low-level jet exceeding 30-35 knots. One caveat here is the BEST dynamics may push off the coast before we can crank again in the afternoon. This should be extremely fun to track the next few days with plenty to work out. It is extremely important to keep expectations in check b/c this is by far a lock and lots have to come together...but all the ingredients are there. Saturday has potential to be quite active as well. 1 Link to comment Share on other sites More sharing options...
TheBudMan Posted August 25, 2020 Share Posted August 25, 2020 This is going to be a W MA/CT/NYC special. Will be spinners in Great Barrington while we have nada. Boooo AEMAATT 1 Link to comment Share on other sites More sharing options...
Torch Tiger Posted August 25, 2020 Share Posted August 25, 2020 Looks like crap 1 Link to comment Share on other sites More sharing options...
Typhoon Tip Posted August 25, 2020 Share Posted August 25, 2020 3 hours ago, weatherwiz said: Finally...we've been waiting all summer for this but the potential exists on Thursday for a widespread...perhaps severe weather outbreak with widespread damaging winds and perhaps some tornadoes all possible. This is a rather delicate setup, however, all the ingredients are there. as always with this type of potential there are numerous caveats and the extent of the potential probably won't be known until early Thursday morning. 1) Morning MCS - there likely will be an ongoing MCS to begin the day (riding along an instability gradient). This will certainly be one feature which complicates the forecast as we would ave to deal with cloud debris and likely subsidence behind the departing MCS. Subsidence can be good as it can help clear junk out faster, however, if it is too strong it can inhibit development later on. 2) Lack of EML/steep lapse rates. lapse rates aren't horrific, but these setups tend to have their severe weather potential (magnitude) vastly increased when there is an EML involved. With that said, combination of temperatures well into the 80's...perhaps near 90 in spots and dewpoints perhaps into the 70's with high mixing ratios should contribute to near moderate instability (again...cloud debris will be a player here too). 3) Rather strong shortwave approaching will be accompanied by anomalously strong mid-level flow with a west-to-northwest MLJ exceeding 50-60 knots with a low-level jet exceeding 30-35 knots. One caveat here is the BEST dynamics may push off the coast before we can crank again in the afternoon. This should be extremely fun to track the next few days with plenty to work out. It is extremely important to keep expectations in check b/c this is by far a lock and lots have to come together...but all the ingredients are there. Saturday has potential to be quite active as well. Can't say I disagree with this notification effort thru yesterday's 12z... 00z, not so much in the Euro, but the GFS hangs on a bit... But In the other thread, I mentioned a couple days ago that D5/6 looked like an "EOF1 bomb" potential for the upper MA to NE states... These baser kinematic structures you're honing in on were evidence back then and as of yesterday - by then D3 ... Maybe like a last season 'threat hurrah' as the summer closes the books and we'll see if this new-ish complexion toward seasonal migration that the operational Euro GFS suddenly paint has legs... Could be a rush job - I think the GFS 528 dm double noded height core amid a continental scoped, sub polar vortex over JB is a bit hard to cough down in late August/early Sept... but, I also covet some personal "science fiction" plausibilities as to why the model is doing that, and it is rooted in evidence spanning the last 6 years... Namely, we've been "continental folding" at transition seasons with unusual proficiency at the books ends of winter. That's John- labeling ...there's no actual identity of that in Meteorological/climate vernacular ...but, I call it that ...it's like super synoptic scaled "Kelvin-Helmholtz" effect. We have velocity surpluses in the mid and upper tropospheric ambience that is tending to kick in very early in transition season, and... lagging unsually long on the way out. The cause is the expanding HC...or in the case of Autumn, the HC expansion as a persistence on-going perpetuated state, is triggering gradient to increase very quickly as the sun's integrate insolation across the hemisphere begins to dim toward the ends of August and particularly...during Sep/Oct ... This increased gradient is directly proportional to the surplus velocity. But why that is important is, the velocity of the jet is "folding" over the top mass of the R-wave fields, and this is increasing/enhancing trough node tendencies earlier in the year of eastern/southern Canada, and also... in May's ... This 'plausibility' is why we have since 2000 experience either synoptic scaled snow chances, or, ... packing pellet virga exploded CU cold waves in Octobers and May some 1/2 if not 2/3rds of the last 20 years worth of transition seasons ...either end. In between? ...DJF/early M .... that HC stuff impinges a whole 'nother issue with raging jet velocities so extreme that it forcing a morphology of precipitation event structures. Anyway, this may seem to have nothing to do with Thursday at this point ...but, it does in the sense that the mechanics are perhaps being exaggerated over what is normal up our way...as these gradient rich events transpire through lingering seasonal warmth and dps... Outside the box thinking a little - In any case, the pattern looks in the 00z run by the Euro to have moved to more a NW flow with some positive shearing ...maybe more whisky line or even MCS-y 2 Link to comment Share on other sites More sharing options...
weatherwiz Posted August 25, 2020 Author Share Posted August 25, 2020 Excellent post! Link to comment Share on other sites More sharing options...
Bostonseminole Posted August 25, 2020 Share Posted August 25, 2020 NAM looks pretty good Link to comment Share on other sites More sharing options...
Damage In Tolland Posted August 25, 2020 Share Posted August 25, 2020 NAM is a full fledged massive outbreak . Wow 1 Link to comment Share on other sites More sharing options...
Cyclone-68 Posted August 25, 2020 Share Posted August 25, 2020 Tornadoes too or “just” severe thunderstorms? Link to comment Share on other sites More sharing options...
Bostonseminole Posted August 25, 2020 Share Posted August 25, 2020 probably will be better the further west you go.. 1 Link to comment Share on other sites More sharing options...
Hoth Posted August 25, 2020 Share Posted August 25, 2020 Ryan's honking on this one. Link to comment Share on other sites More sharing options...
weatherwiz Posted August 25, 2020 Author Share Posted August 25, 2020 oops I made my post in wrong thread. too lazy to delete and add here Link to comment Share on other sites More sharing options...
CoastalWx Posted August 25, 2020 Share Posted August 25, 2020 Setup looks good in SNE. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted August 25, 2020 Share Posted August 25, 2020 2 minutes ago, CoastalWx said: Setup looks good in SNE. NW flow is where it's at in SNE for some of our best severe events. Link to comment Share on other sites More sharing options...
Henry's Weather Posted August 25, 2020 Share Posted August 25, 2020 Do we make a thread for Saturday too? 1 Link to comment Share on other sites More sharing options...
Bostonseminole Posted August 25, 2020 Share Posted August 25, 2020 28 minutes ago, CoastalWx said: Setup looks good in SNE. the dry crew said it looks like crap. 1 Link to comment Share on other sites More sharing options...
Torch Tiger Posted August 25, 2020 Share Posted August 25, 2020 48 minutes ago, Bostonseminole said: the dry crew said it looks like crap. Yeah, locally it is a garbage can. Maybe something SW Link to comment Share on other sites More sharing options...
ineedsnow Posted August 25, 2020 Share Posted August 25, 2020 Big day Thursday and spc already has us highlighted for Saturday 1 1 Link to comment Share on other sites More sharing options...
Chrisrotary12 Posted August 25, 2020 Share Posted August 25, 2020 18z NAM says what moisture. lol Link to comment Share on other sites More sharing options...
CoastalWx Posted August 25, 2020 Share Posted August 25, 2020 18z NAM is a long track SUP through CT. Link to comment Share on other sites More sharing options...
weatherwiz Posted August 25, 2020 Author Share Posted August 25, 2020 I would like to see stronger height falls. I do like though how models seem to track some steeper lapse rates into here...and to verify it's not a COD algorithm forecast soundings do exhibit a weak EML signature Link to comment Share on other sites More sharing options...
weatherwiz Posted August 25, 2020 Author Share Posted August 25, 2020 I also wonder how the morning MCS potential influences things later in the day. Those are always a significant challenge...most times they completely kill potential, however, there are times they can enhance potential. 1) Will there be s/w subsidence behind it? As explained before, this can be good in that it clears out cloud debris quicker, however, it can also be bad b/c if that subsidence can't be overcome later, convection becomes suppressed. 2) MCSs can certainly leave behind residual boundaries and these can be a focal point for convection initiation and they can also locally enhance tornado potential...depending on how the storm motion is with respect to the boundary. 3)Timing of the MCS...this is actually rather huge...is it bright and early or late morning. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted August 26, 2020 Share Posted August 26, 2020 All three days Thursday through Saturday look troublesome or certainly could turn out that way with that front oscillating in the area ... accentuated helictites long it with unusual thermal gradient for this time of the year either side is intriguing. Seems that EOF1swarm idea had shifted more to Saturday with organized cyclone mechanics in the area but the boundary itself could be active for a couple days before that ...wherever ultimately sets up Link to comment Share on other sites More sharing options...
weatherwiz Posted August 26, 2020 Author Share Posted August 26, 2020 6 minutes ago, Typhoon Tip said: All three days Thursday through Saturday look troublesome or certainly could turn out that way with that front oscillating in the area ... accentuated helictites long it with unusual thermal gradient for this time of the year either side is intriguing. Seems that EOF1swarm idea had shifted more to Saturday with organized cyclone mechanics in the area but the boundary itself could be active for a couple days before that ...wherever ultimately sets up Let's hope we can get at least one of these days to work out. I think historically when we seem to have these multiple days of potential we typically get one to work out. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted August 26, 2020 Share Posted August 26, 2020 10 minutes ago, weatherwiz said: Let's hope we can get at least one of these days to work out. I think historically when we seem to have these multiple days of potential we typically get one to work out. Ha ha yeah this isn’t the panhandle of Texas from late April to early June when you have 45 straight days of visible crispy super cells rollin under the tropopause 1 Link to comment Share on other sites More sharing options...
CoastalWx Posted August 26, 2020 Share Posted August 26, 2020 NAM is really interesting. Not sure I can remember such rapid WAA and rapid destabilization like it shows. Link to comment Share on other sites More sharing options...
Ginx snewx Posted August 26, 2020 Share Posted August 26, 2020 10 minutes ago, CoastalWx said: NAM is really interesting. Not sure I can remember such rapid WAA and rapid destabilization like it shows. Which NAM? Lol 3 k has Laura at 915 with 4k Cape Link to comment Share on other sites More sharing options...
dendrite Posted August 26, 2020 Share Posted August 26, 2020 3 minutes ago, Ginx snewx said: Which NAM? Lol 3 k has Laura at 915 with 4k Cape I saw an 896mb in there on Dupage. lol. Link to comment Share on other sites More sharing options...
yoda Posted August 26, 2020 Share Posted August 26, 2020 @weatherwiz is going to go full weenie when he sees the new Day 2 from SPC... ENH risk with 30% hatched wind... 5% tor... and 15% hatched hail in SE NY/NE PA/NW NJ 1 1 Link to comment Share on other sites More sharing options...
Torch Tiger Posted August 26, 2020 Share Posted August 26, 2020 The CAMs look very good for CT, NY, maybe W MA. 1 Link to comment Share on other sites More sharing options...
Damage In Tolland Posted August 26, 2020 Share Posted August 26, 2020 Enhanced risk. 5% TOR and 30% Wind https://www.spc.noaa.gov/products/outlook/day2otlk.html Link to comment Share on other sites More sharing options...
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