Typhoon Tip

i've noticed a distinct 'pattern of posting behavior' that's gotten somewhat predictable between you and Steve -vs- Kevin in this on-going web banter over summer weather. whenever the Euro comes out at 00z and may happen to have a hottish look in the late middle/ext range, invariably there is a post like this awaiting in the morning that extols the celebratory virtue of the muted summer of cool low humidity... funny - it's like you are anticipating Kevin's rage and trying to cut if off at the pass hahahaha

yes I figured you were seeing a larger array of members then than 'standard 12' that's disseminated - what I was dancing around is, what is special about those 12 versus the 54 ... ( I think the total member count is higher than even 21 but don't quote me ...) anyway, the thinking being, if the other ones are not disseminated because they are more experimental (say) than that would lower any confidences that much further. but we know it's all meaningless for now anyway. what I found to be most presently noteworthy of all is that the GFS operational model began churning out runs with a TC out there in the 'Verdi rail service some 13 days ago and has never deviated. that's really pretty f'n extraordinary model performance on this ... Presently the wave has become better defined convection-wise with even early hints of curvature/banded overall layout on IR channels. Nhc concurs and has this in the 70th percentile for development beyond the near term. ha! you know what - the next step will be the GFS doing a 1938er at 13 days lead time and us 'weathering the storm' of passive ridicule from Meteorologists swooping in to reminds us we are all just provincial rubes with too much imagination kidding of course -

I saw one member out of the 12 from 12z this morning that involved our region with a tropical threat out around 260 -295 hours.

glad you brought it up though ...heh. i noticed that the GFS operational (so far - keep in mind ...nothing's verified yet) hammered the SE Canada NW flow looking all the while the Euro was threatening with headliner Continental heat... then, we get D 9 thru 13 inside of D 7 and we're seeing the Euro reload the trough repetitively, which establishes what the GFS said all along, it its own mean. ..ie. correction ... anyway, it's a recent detail in the late middle/extended range modeling behavior that's sort of under the radar...

the next 7 to 10 days in the bevy of guidance/mean therein strikes me as the old NW flow buffer deal on a planetary scale... Super hot Plain's heat would rip off fragments in that sort appeal ... from time to time these will pass through the Lakes then shunt/dive toward the M/A, sparing NE from what looks like a very hot continental pattern from a distance. The 06z GFS-para is the only run of any model that I can find that bucks this idea ...oh D11-15, but at that range the proverbial coin apes an Olympian gymnast. It almost seems like any heat at all up our way is by physical law always going to be a fleeting potential ...almost as planetary accident, because of the base-line/rest-state circulation structure of having the continental-topographical bulge over the Rockies cordillera. It seems the models (rightfully so) can't sustain ridging in the east (...unless of course it means f'ing up a good cold coastal in the winter. .. j/k). Seriously though, the CDC and CPC have been hammering positive PNA, and the pattern looks the part, despite the idea that the index is not correlated significantly enough over North America during JJA... I've always questioned that finding because of times like these...

...sort of... Though it's too early to assess air mass origin, there is some semblance still that ridging could try to become more prevalent in the E here over the next week to ten days. It may end up being more of a 4th through the 8th sort of thing, too - "Weather" we just get standard departures associated with ridge anomalies, or something more because of having SW cooked troposphere in the mix is too early to tell.

Ooh ooh, let me ... won't speak for Scott, but, there are two schools here. One is reality, the other is the model's en masse collective virtual reality. Ideally, we want the latter to be in the 100th percentile as far as depicting where the weather pattern will go and ultimately verify... But the present state of the technology in modeling is ... oh say the 90th percentile for D1 and 70 for Day 3 and 55 for Day 5 ...and on and so on down to meaningless D 9 Euro snow bomb coastal histrionics that we cherry pick data to support actually happening.... Why that is important is because... we do sometimes get 'heat domes' back east, but, the models will tend to bias toward what is called the 'Perennial North American Pattern' ...ever more so the deeper out in time is the view. By D11 - 15? heh... The models may error there, to put it nicely. But "if" an d when destiny has a flat ridge in the east (or a ridge event that is weak) ... there is little hope the models won't mute that out of existence. But, what is the PNAP pattern and why? It's there because of the summation of mountain torque over western N/America...with the ambient Pacific westerlies impinging upon the elevations of the Rockies (Canadian all the way down to Mexico). In the absence of a transient pattern forcing (which are short term modulations that enhance the flow structures and orientations) the rising motion over the Rockies will tend to bend to the left because of the Coriolis Force... that imparts a natural "bulge" in the planetary wave signature over the western part of the continent. In simple terms...even without a ridge in the west, and a trough in the east, any flow over the planet's surface that is forced up and over the N-S oriented mountain chain is going to curve up and then back down to the N than S... That really is the base-line perennial north-American pattern orientation. Sometimes (then) forces countermand that and you end up with troughing in the west and ridging in the east, but because of that base line planetary forcing, it's just easier for the pattern to support what you are observing - and, when/if ridges are supported by the pattern out west, they actually get a positive feed-back. It's like we have a disadvantage to jumping high genetically back east... We can do it, but we just have to work a bit harder. Which means that by proxy number ...our frequency of dunking the ball is going to be a little rarer.

I guess ...if you buy it. The GEFs seem to be engineering an opposing look there, that is perhaps merely being obscured by having heights sort of on the high side everywhere. But, structurally every time a few cycles struggle to edge the pattern more WAR-dominated ... some run comes out like this 12z GFS/operational that locks a 600 dm height monolith out west ...almost like it strained to lift the barbell for two days, only to let fall by collapsing the flow in a single run back to west-is-best for heat. If that construct evolves no more summer... It's like early autumn from here on out. Can't say from a sensible impact point of view that would be all that bad. It also seems y'all go by the Euro camp and any derivatives almost entirely though - so..

...true, but ... using the EPS right now "seems" like eliding. That aside, there is a real trend that's been evolving to generate a heat departure period, roughly from the end of the month through the first week of July. We just don't know the extent of that. The last heat wave began in the runs with this sort of arguable ridge signal - just to keep that in mind.

So... any particular reason why the EPS is more right than the operational?

welp ...despite the whole multi-year on-going rip poke to rip poke battle between Scott and Kevin ... the following comments do not reflect any perspective involved in their "debate" I think the 00z Euro is completely out of sync between surface and aloft over easter N/A (appr of 110 W). It strains believe-ability that it, the GFS, and both camps respective ensemble means all maintaining positive heights exceeding 582 DM from Days 6 through 10, while having less in the way of blocking/confluence over eastern Canada, would succeed in allowing that much suppression of the ambient polar boundary/ surface reading in the 60s in New England. That seems a little bit contrived by their correction schemes.

oh wait ... haha... forgot about that whole remnant thing -

We may have a sneaky 89.7 degree heat wave underway for northern Orh, Middls, and S NH typicals ... It's a long shot, but I'm noticing the Euro and NAM have backed off the what feeble CAA there is behind that front tomorrow night and may Sunday may trend toward the upper 80s. We've already popped 90 today, and probably will tomorrow... Hell, there's nothing else to follow - Also, the Euro's got a low grade heat wave out there in the late middle/ext range - it's had this for a couple of cycles now, with hints prior to that; so it's trending. The GFS has heights that would support, but engineers curvatures that prevent -weird. It carries full-bird troughing through 585 DM heights ... We've had temps near 100 at 582 in the past... I swear ...NOAA must've parameterized that model to hide hot periods...

Could be a warm mank? It won't be misting per se, no .. .But, that look is 82/72 type stuff there in the Euro and has been for many runs. Thing is, the air mass is suppressed S but not evacuated off the continent...by last evenings front... Over the next day or two that boundary washes out and the SW flow resumes, transporting the air mass back in but, this time it lacks the SW EML stuff... So it's kind of a DP sack sticker soup on the back side of this/return flow.

I'm a little leery of that interpretation actually ... not that you asked - heh. Buuut, the Euro shows (as has GFS operation on some solutions..) plumes of periodic SW expulsion embedded in a kind of heat conveyor that keep getting sent down stream during that entire D4.5 through D10 range. Some runs that is more evident than others, and not certain which day ...which doesn't lend much to confidence no. However, 'the trough' return sentiment ...yeeeah, it's not the same beast as before really. There are structural differences overall that have me wondering if we aren't a single run away from getting said continental stream of plasma ejecta to waft up this way. We don't need "ridging" per se to get that to happen - Sunday shows that, and I don't see any reason why the upcoming pattern can't repeat. Might actually be a normal to above normal oscillatory thing. anyway, the trough is flat. We seem to have lost the meridional characterization of the flow in lieu of a more longitudinal look so I'm a little leery of being too optimistic about the heat being gone.

Did anyone notice that GFS tried to put a 600 dm ridge node in the mid riff of the country, with 850 mb temps approaching the mid 20s C as far N as the U.P. of Michigan ? Probably not ...because rightfully so, we should not be looking at a 384 hour anything that comes from modeling technology with much credulity ... still, I get a stinkin' suspicion this summer may bring the GW goods home to roost at some point - heh....er should we say 'roast'

Euro the opposite of that impression... Subtle but important distinction on this last Euro run is the tendency to pancake the latitude depth/extent of the deep layer trough set to replace the present ridge toward next weekend. That's mid levels... The surface read of the synoptic evolution rolls the region from the upper OV up through NE right back into a SW flow and even imparts +16 C 850 mb air. What's actually going on is that the mid week high pressure that intrudes from the N and truncates the heat merely pinches off the continental heat transport scenario presently in operation. Once the high normalizes out ... said air transport resumes. But by then, it contains some seriously rich DP air that tsunamis toward the weekend. I've seen this before in summers... For those that covet these interruptions of heat, NE is your destiny! It's basically that situation that sometimes sets up where the lower troposphere gets into "out of phase" with the mid levels... The mid looks sort of like the native perennial PNAP look, with flat western ridge, eastern trough coupled state, but, the lower troposphere may as well still be in a Bermuda round-house pattern.. We'll see how the runs modulate things going forward... I haven't seen the 00z GFS personally -

Scott or Will may have a better informed idea re those specifics than I. But I seem to recall a couple spring >> summers in the 2001 thru 2004 years that had some early heat. I recall April of ...I wanna say 2002, we had a freak warm month that year. Even when sea breezes came in they were ineffectual at really knocking things back the usual 35 F, and those air mass remained shallow, often erased overnight as a repeating characteristic of events. That summer did go on to being pretty warm - 4th of July was a scorcher. I get why you're asking but ... I'm not sure that's a useful conclusion to draw (assuming you are thinking repeating circumstances). If I'm being presumptuous than apologies but it could be exactly the same between April and June of 2002, as it just was now in 2017, and the summer would have equal probability in any direction. And just by experience I've seen that go either direction. I've seen early heat in May flip back to cold Junes that only mustered a recovery to normal in July... then a late heat wave at the tail end of August ...just before a mild Autumn that won't freeze... In other years, reverse all that. I think of Summers as being the "unmanned fire hose" season, where the teleconnectors have left it to spizzle and flop around. The planetary wave numbers become increasingly abundant but more importantly ... transient and weakly bounded. The flow becomes nebular. That is part and parcel in why some of these indexes lose their commodity between roughly mid May and the end of September.. It doesn't make the teleconnectors useless (imho) but, it makes their day-to-day dependability rarefied. It's probably really a matter of opening up thresholds though. If a PNA moves say, +1 or -1 SD in July, it doesn't mean nearly as much as if/when it moves that much in January... But move the former...I dunno 3 or 4 SDs in July, then we probably get something back from that particular index in terms of signaling pattern forcing. The trouble is, it almost never moves that much in July. Same holds true for the NAO ...EPO...etc, etc.. But I'm digressing... Point is, the 'unmanned fire hose' season means that we spray anomaly distributions all over the place with less obvious controls as to where/why they are coming from. So logically, it would "seem" harder to depend upon a warm say April, and think that means much for June. The earliest (per my experience) that the season to season "season" begins is roughly October... It seems that biases in October can sometimes weakly correlate in two month increments... Nov --> Jan...etc... but don't quote me.

20 or 21 C 850s on this 0 Z NAM over much of central eastern mass Sunday afternoon

Fascinating statistical result... Not to roll eyes but ... heh, environmental modeling that is/was/are designed to predict the effects of global warming have been hammering for years that it's not just about the "warming", but in large part is about chaos and havoc ... basically a lack of stability in the system. Freak extremes actually in both direction is/was/are part of the characterizations. Maybe this is all just excessive variability related to that. interesting... Either way, two heat waves in a spring predominated by a cool wet complexion is an interesting story

Yeah so as this is coming into better focus in the various runs it's becoming clear that this warm up in coming will probably limit to middling heat - One aspect I'm seeing that I don't like for bigger heat between detroit and boston's latitudes is that the geostrophically balanced mid-lvl winds just over top the ridge across southern and southeast Canada are too strong. Heat domes are fragile at our latitude ...you can't really run that kind of dynamics through there or invariably we'll be sending god knows what wedging S...be it BD's or outflow boundary or whatever the models can think of and the atmosphere will deliver to dent it back. That's not to say we won't pop the mid 90s on one of those days but this doesn't look like the same beast of a heat departure it did earlier on...

Euro was pretty hot from Saturday to the end of the run... (most know this .. just a morning diversion here -) The torridity will come down to how much DP is in that mess... If it's 90/60 ...not so bad but pedestrian AC requirements ...then needs go up from there. With all the rain we've had and at a surplus, this is very unlike last year at this time. There's a lot to give back to the atmosphere, at least locally, for if/when we pass 90+ air mass potential heating over top. Some of that is obviously also transport dependent, but in situ soil moisture is shown to effect heating potential pretty readily so if the wind is light-ish and it is 19 C at 850 mb with June insolation bakin' the hell out of things, we could see some added theta-e to the column there... It would hold the temp down a couple but give back in DP ...etc.etc. The GFS is flattening the ridge just enough, and throwing also just enough little indiosyncratic perturbations in the flow to nix this ridge/heat dome and heat wave down. In fact, the PARA MOS numbers fail a 'wave out of it all together. I've noted my self in the past that the GFS hates ridge domes and I wonder with this thing - Probably what happens is midway between the Euro and GFS which ... 92 to 95 might max this on either Sun Mon or Tues... Still in contention whether it breaks by BD or standard fropa on Wednesday ... But the Euro suggests the entire domain from coast to coast remains near or above normal in both heights and thickness so it probably still remains on close side.

The last of the cloud shield has finally peeled away ... and the winds are advecting in the warmth from eastern Ontario whatever

Euro actually started flagging the hot Sunday yesterday ... sort of bumped up the 'heat wave' by a day. Brian's right about the entry day often muted by global models; they do that often and that Sunday smacks of GFS fantasy limitations of BL expansion and local study and so forth, all of which look maximized sooner than Monday. How about the monster front on Tuesday now... ? Compare that to the 00z Euro - one of these models has no clue.

Looks like one of two things will happen with that 'heat wave' early next week... 1 ... it will end up just being 3 to 5 days of 87 to 91 with gradually building DPs... 2 ... sometimes the models will see a big ridge (trough) and elaborate potentials therein in their extended range... Then, summarily seemingly engineer any way physically plausible to mute/damp out their own signal, only to bring it back in nearer terms to something ...perhaps 80 to 90th percentile of the original vision. What that would mean for this is that it will look sort of 87 to 91'ish for the next few cycles ..then, come Friday's runs or so the ridge comes back to more of an unimpeded continental dragon tongue as opposed to weird vorticity shrapnel and a non-chartable off-set 850 mb plumes of relatively cooler air embedded in the continental baroctropic hot air mass... Those idiosyncrasies cut high temp potential pretty significantly at the 40th latitude.. Thing is, they can be real.. A lot of those "dents" in the heat are more likely to exists in a less anomalous height version of the ridge because ... slightly less suppression ...blah blah Which, the 00z Euro was kind of did try to make the air mass more homogeneous that anyway... It 86'ed its phantom [looking] BD for Monday that it decided to insert in that 12z run from yesterday.... Now placing any boundary roughly PWM to BTV type of axis... If the ridge comes back over the late week guidance, more in line to the original looks than even that would be too far S with any perceived boundary. Anyway ... details aside ...finally we are escaping the giant synoptic scaled 'tuck' pattern that keeps depositing cold plumes into Se Ontario... AT this point it's warmer up in Dead Horse than it is in NE for f sake ...