Typhoon Tip Posted July 4, 2016 Share Posted July 4, 2016 By our local vernacular "big heat" I figure should be 95 + , given to our climatology for such numbers, acclimation and relative impact. Two cycles ago the Euro machine output was 100 F at KFIT; as of last night it is 92-97-97 for Tuesday, Wednesday and Thursday of this week. This has been signaled for quite some time, ...though, the synoptic evolution has left some to be desired for the 'cleanliness' of the period. The thing is, the ridge and associated -PNAP expression on the circulation medium is 'flat' in appeal. Models such as the GFS have been having trouble with that, because (perhaps native to the GFS) the model is very sensitive to perturbations in the system ...tending to over-develop seemingly innocuous non-physically capable features. Case in point, here is the GFS' 00z, 500 mb geopotential/vorticity depiction for hour 24: Now, here is the 00z moving further out to hour 36: It is not entirely clear what the origin of the red 'X' annotated 'dent' in the geopotential contouring is that is drifting E over the vicinity of Colorado. Easily dismissible as mere noise. The approximate wind velocities leading up to the hour 36 interval are around 22 kts when approximating, which works out to ~ 600 nautical miles of translation speed. Short waves don't translate at the same velocity as the winds around their circumvallate, anyway ... so all together, this feature's origin really appears to be spontaneous - although there may by details between the pressure levels of the model's domain space (unclear). Either way, the model then substantiates this 'new' event as slowly intensifying short wave, now looking at the depiction out toward 72 hours: Thus, by 72 hours, it was evolved strong enough to effectively block the continental conveyor of hottest air from passing through key-hole latitudes of the upper OV, which is typical/climatological for delivering bigger heat to the New England region. The problem is, because of that over all suspect evolution, is it even real? Short waves have to come from somewhere - perhaps there's one helluva butterfly hovering over the Grand Canyon.. The other models, Euro for example...don't do that. In fact, it shows 20 to 21 C air passing over our ~ lat/lon ...having not generated such a blocking permutation in the flow: The result of these minor differences having a sensible impact meaning - perhaps not hugely so... but, the GFS is probably having difficulty sustaining 90 F highs there, because that's probably enough of a disturbance to induce cloud coverage, or even convective concerns ...obviously both of which would stop the Euro type solution of a heat wave, mid-stride big heat day. The Euro depiction would likely support 97 or even 99 F at locations like Nashua, Manchester, Bedford, down in Mass' Fitchburg, Bedford and Shrewsbury, interior SE zones and over through regions of heat prone Connecticut. Wouldn't be out of the ball-park to assume someone in those areas put up a 100 in that look, either. Not in the GFS though. This really isn't an indictment of the GFS - per se - either. Even the Euro has had a couple cycles spanning the last five where it was less impressive. This is a flat ridge toting some mixed Sonoran/SW heat ejection with more typical continental summer cooked air. But that 'flatness' means that it is susceptible to permutations. These will mean the difference between a low impact heat wave (in its self above 50% confidence), to perhaps one or two days of which being a bit more memorable. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 4, 2016 Share Posted July 4, 2016 By our local vernacular "big heat" I figure should be 95 + , given to our climatology for such numbers, acclimation and relative impact. Two cycles ago the Euro machine output was 100 F at KFIT; as of last night it is 92-97-97 for Tuesday, Wednesday and Thursday of this week... Can't argue your points, as you say and like most warm season events in New England (severe, tropical) it takes a near perfect set up to get 100 F. Overnight EPS has a strong signal for 90+ in the favored heat corridors, having its eyes on Wed for the max heat. Still looks like it has a little too much troughing in the east to allow the heat to pinch off an head our way, instead nudging it just south. It does break off a tiny piece of 20C H8 air, but it never makes it past the Hudson in the means. GEFS kind of follow the op, in that they say no big deal on the heat, run of the mill for this time of year. Which in a sense it is, but with a few EPS members shooting 105 at ASH that would be noteworthy. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 4, 2016 Author Share Posted July 4, 2016 Can't argue your points, as you say and like most warm season events in New England (severe, tropical) it takes a near perfect set up to get 100 F. Overnight EPS has a strong signal for 90+ in the favored heat corridors, having its eyes on Wed for the max heat. Still looks like it has a little too much troughing in the east to allow the heat to pinch off an head our way, instead nudging it just south. It does break off a tiny piece of 20C H8 air, but it never makes it past the Hudson in the means. GEFS kind of follow the op, in that they say no big deal on the heat, run of the mill for this time of year. Which in a sense it is, but with a few EPS members shooting 105 at ASH that would be noteworthy. Indeed ...which is part and parcel in why I'm so nerdingly fascinated by big heat up our way seriously, it's hard, thus, ...rare, to come by. Folks should be impressed by rarity.. blah blah. but that's just me. But, the 12z GFS did ...maybe back off that weird perturbation in the flow it has in OH through 80 hours, yet it still hesitant to depict the hotter parcels/mixing depth layers (as you noted) getting past the Hudson. ...least that's the way it looks to me now.. I don't know what the Euro will show here in a hour but one thing I have read about that ECMWF regards the correction terms they use - the literature actually says in an attempt to smooth out these sort of GFS oper. thing - plus, it's got that unflappable <= 4.5 lead performance, too. i'd suppose i'd give it this a 10% chance of 100 at ASH and 55 or 60% chance at 90-90-90 Link to comment Share on other sites More sharing options...
OceanStWx Posted July 4, 2016 Share Posted July 4, 2016 i'd suppose i'd give it this a 10% chance of 100 at ASH and 55 or 60% chance at 90-90-90 Sounds like a fair representation of the EPS distribution actually. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 4, 2016 Author Share Posted July 4, 2016 GFS MOS is, if anything, even cooler for mid week... fascinating. Doesn't even bring a heat wave to said areas... in fact, no 'heat' really at all. hmm. Link to comment Share on other sites More sharing options...
dendrite Posted July 4, 2016 Share Posted July 4, 2016 GFS MOS is, if anything, even cooler for mid week... fascinating. Doesn't even bring a heat wave to said areas... in fact, no 'heat' really at all. hmm.The GFS is lurking a shallow BD nearby during the week. Maybe MOS is "sensing" that? I've barely looked so I have no thoughts on how legit it looks... Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 4, 2016 Author Share Posted July 4, 2016 The GFS is lurking a shallow BD nearby during the week. Maybe MOS is "sensing" that? I've barely looked so I have no thoughts on how legit it looks... my statement was false, tho - i missed Tuesday on that... it has that day at 92 ...it's just that it's thumbing the idea shot-gunning 86's the rest of the way. A ways off from those Euro runs or the EPS even (Ocean') from 00z. having said that, the 12z Euro tries edge back a ways... more like 19 C at 850, at max thermal ridge axis.. Plus, "as is" that depiction would almost have to have coastal heat trough convection initializing which would hamper a hot day further (Thursday). i'm curious what the Euro ensembles look like later. not a lot of margin for error when the ridge is so flat - which is weird - wondering why that's happening anyway. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 6, 2016 Author Share Posted July 6, 2016 Well, it appears clear the GFS was out to lunch on this this week. Most climo sites en route to 93 to 97 for a high today - and probably, beat MOS by a tick or two, which is typical for machine vs reality (for whatever reason) nearing the apex of warming potential in the spring and summer. What is in jeopardy is actually getting a 'heat wave' officially. yesterday needed to be 90 to pull this off... Today and tomorrow are slam dunks but we stopped at around 86 most places yesterday. Perhaps Friday will sneak a high before backdooring and/or convection contamination roll thru but that's a long shot. One thing that is humorous though .. the NAM is 60s and misting in slate-gray post BD misery Friday afternoon, and the GFS still cranks 85 at MOS locations like KFIT... so, it seems that the whatever the consensus is/was this week, the GFS just want's to be opposing at every point. - heh. nice short duration heat pulse here, nonetheless. Link to comment Share on other sites More sharing options...
tamarack Posted July 6, 2016 Share Posted July 6, 2016 Well, it appears clear the GFS was out to lunch on this this week. Most climo sites en route to 93 to 97 for a high today - and probably, beat MOS by a tick or two, which is typical for machine vs reality (for whatever reason) nearing the apex of warming potential in the spring and summer. What is in jeopardy is actually getting a 'heat wave' officially. yesterday needed to be 90 to pull this off... Today and tomorrow are slam dunks but we stopped at around 86 most places yesterday. Perhaps Friday will sneak a high before backdooring and/or convection contamination roll thru but that's a long shot. One thing that is humorous though .. the NAM is 60s and misting in slate-gray post BD misery Friday afternoon, and the GFS still cranks 85 at MOS locations like KFIT... so, it seems that the whatever the consensus is/was this week, the GFS just want's to be opposing at every point. - heh. nice short duration heat pulse here, nonetheless. MHT touched 90 yesterday, so they might have a tiny chance at a heat wave, depending on when the clouds roll in tomorrow. Anyplace north of there is likely to be one (or more likely, none) and done. Obviously, the above post addresses mainly SNE, but much farther north, CAR's entire CWA has forecast highs tomorrow ranging from 60 to low 70s, with RA likely. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 6, 2016 Share Posted July 6, 2016 MHT touched 90 yesterday, so they might have a tiny chance at a heat wave, depending on when the clouds roll in tomorrow. Anyplace north of there is likely to be one (or more likely, none) and done. Obviously, the above post addresses mainly SNE, but much farther north, CAR's entire CWA has forecast highs tomorrow ranging from 60 to low 70s, with RA likely. MHT, ASH, SFM, and CON all at 90 or better at this hour. Link to comment Share on other sites More sharing options...
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