Leaderboard - 33andrain Jump to content

Leaderboard


Popular Content

Showing content with the highest reputation since 06/18/2019 in all areas

  1. 7 points
    Thought I'd share some of the observations and "in-situ" data i've both collected and monitored. The late April into early/mid-May featured a violent, robust, and severe weather outbreak the U.S. hasn't seen in years! The synoptic and larger-scale forcing that had transpired leading up to this aforementioned period, in a way, dictated the inevitable collapse of the pacific jet-stream giving way to a meridional orientation. If we also look at the 90-day averaged OLR anomaly, we can see what has kind of been both the "elicitor" and overall background base state "signal". Poleward of that standing convective "hotspot" (which to add, still think this weak-Nino doesn't erode and give way to Nina so quickly like some are already presuming), we've gotten some anomalous jet extensions poleward of these ridges. In essence, what i'm trying to show from again - my limited knowledge thus far in this area (albeit a significant boost in comprehension and understanding thanks to some of you guys in here!), and as stated - "in-situ" learning via trial and error, of how we could predict the catalyst for breakdown and retrogression of the RWT. I've taken consecutive zonal/integral AAM tendency plots and just annotated on them via a GIF. Basically, what is shown initially is an episode we had back in April/May as spoken above. It's known that these episodes, or periods, happen over ~ 30-50-day time scales, with even specified periods happening potentially between 10-20 days. On that note, what dynamic variations can speed up such episodes? Anyhow, we can see the poleward U-wind accelerations propagating poleward from the tropics into the mid-latitudes over time before not long, -U shows up south of this poleward propagating westerlies, therefore, an expected breakdown and soon-to-be retrogressed process that'll take place over the next week exactly like what had transpired back in May. Notice the jet-extension thus far beginning June 1st. The last image has been annotated from IBM Chief Met. David Gold, which he discussed the overall "framework" of this synoptic forcing event, but going back to my original content - this entire series of tropics-extratropics interaction via utilizing the GSDM, can we possibly only get better at monitoring these real-time components and forecasting at certain lead times, like lets say, over 2 weeks? We can garner clues and deduce some ideas, but what also makes this tough as i've come to learn, just as the experts here already know, there is so much more to this than just oversimplification that i've presented. This base-state has had a role, and if this -VP200 weren't the way it's now; therefore, the sub-seasonal atmospheric variability would be different. This implies different propagating circulations, and reflecting AAM torques likely. Basically, the premise of this post was to, again, share my observations and have it open for fantastic discourse because it's interesting, and rather "mind-blowing", that many forecasters, meteorologists, experts, etc., have come this far in an imperfect science and still have so much to learn. However, if we can just gain an "advantage" little by little, it can only bring us closer to constructing a more "polished" forecast for long range lead-times.
  2. 7 points
    2 more rounds of rain to come through this morning. Then we move on from this godforsaken week of shitty weather.
  3. 7 points
    A handy addition is that retrospective data That laddering upwards trend of the GWO progression through June 2006 tells the story for me - it depicts a slow steady consistent rise in +ve momentum transport through the month with a transition to the Nino attractor phases by late month. Therefore, as Tom alludes to, its not always the actual GWO wind-flow phase per se that matters 100% of the time (though it usually involves some kind of representative synoptic reflection according to time of year and associated seasonal wavelength, plus the state of the NAM) but the direction of travel of the atmospheric circulation itself. Seasonal wavelength changes play a large part with the signature Pacific amplification and downstream trough/ridge/trough sequence being most focussed at certain times of the year during primarily La Nina driven circulations. The converse holds true with the jet extension phases in the Pacific during Nino-esque +ve tropical>extra tropica torque transports where low pressure and cyclonic induced conditions tend to prevail as the upstream Asian-Pacific pattern is flatter and faster and with a more split jet aspect downstream. In summer , the Pacific ridge and downstream retrogressed sub tropical ridges underpinned by easterly trade wind prevalence as characterised by a La Nina trending atmospheric circulation peaks in July and August - so its quite conceivable to have a representative relatively higher GWO state (for example in low amplitude 'neutral' phases 8,0,4), say, in May and June - and still have an a-typical synoptic pattern produced by a misaligned tropical convergence signal matched in the Indo-Africa hemisphere rather than the Pacific - acting 'destructively' on the base state. This more WH tropical signal meaning that AAM tendency is restricted and hence the GWO, atypically, not in a representatively more Nino type phase As high summer approaches, and tendency tanks increasingly further -ve to couple with a change of location of the tropical standing wave to Africa and the I/O - the amplified Pacific and Atlantic profiles become completely defined and augmented by the seasonal wavelength - and this can lock in troughs on the 'polar side' of these upper ridges - perpetuated and sustained by the thermal differentiation of cool upper air and strong surface heating c/o maximum intensity solar insolation. Conversely a +ve trending momentum will systematically weaken these oceanic upper ridges c/o steadily reducing trade winds and the rossby wavelength starts to relocate the ridge and trough pattern accordingly - augmented by the forward moving changing seasonal wavelength. So its clear that in June 2006 there was a persistent 'constructive' trend to the larger scale rossby wave progression - and that despite the GWO being in low phase in early to mid June, anomalous circum-global Branstrator ridging was enabled at continental rather than oceanic locations at mid latitude in tandem with a definitively +ve AO mode across the polar field. This type of synoptic progression creating large amounts of atmospheric divergence as high pressure zones over large continental landmasses create huge upward spiking temperature profiles - with both surface and upper air profiles reinforcing each other in tandem dwindling soil moisture profiles and solar insolation feedbacks By July 2006 when seasonal wavelengths were most receptive to align with a +ve momentum trend, these anomalous ridges took on a particularly Nino-esque reflection and coincided with some of the hottest weather across quite a few parts of the Northern Hemisphere. In many respects this type of progression happened last year. The GWO was representative of anomalously low atmospheric momentum in the first two thirds of June 2018 - depicted by the GWO in high amplitude La Nina phase 2 However, as the momentum plot indicates, there was a sharp upwards +ve momentum transport surge at the end of June 2018 which resulted in the GWO very close to engaging the Nino attractor phase 5 by mid July. If this rally had not occurred as seasonal wavelengths dictated it to, then the anomalous ridging profiles of the first half of the summer would have re-configured to classic retrogressed Pacific and Atlantic ridges. Instead, it meant that the early summer ridging was able to peak well into July. Much s had happened in 2006. The remainder of summer 2018 indeed featured an increasing macro scale Nino standing wave influence - but the extra tropics continued to manifest mixed and sometimes -ve momentum aspects such that momentum fell back once more through the late summer - and no surprise the scale of the multi wave ridging pattern also started to break down once more - even though global relative AAM was up to 2SD higher than the low point in June 2018 Just to add to this analysis in respect of this summer - I think that judgement in respect of the Nino standing wave and longer term atmospheric angular momentum tendency trends, its sensible not to get too over focussed on trade wind shear effects,, but to watch the passage of the MJO related convectively coupled kelvin wave across the EPAC as there are already indications this may be induce cyclonic activity that proxy data identifies but is not so well identified by some of the generic modelling - and a signal that the Nino standing wave may start to re-engage in the medium and longer term. Its wise I think to differentiate between the effects of the MJO "mini cycle" and the broad-scale macro scale feedbacks which are determined by processes of upwelling and downwelling waves. It is quite conceivable that a downwelling wave in process may alter any pre-conceptions about any sustained -ve tendency returning following and which might be simply attributable to the next suppression phase in the Pacific - a quite natural part of the intra-seasonal tropical cycle. With the lagged effects of late Spring season downwelling effects in respect of final warming of the stratosphere largely extirpated, the tropics returns as a driving fulcrum within the extra tropical domain and will be more sensitive to wind-flow vicissitude and associated torque altercations and contretemps. Especially with a mercurial mix of momentum forces converging close to the dateline, and the extra conundrum of a twin standing wave in the Western Hemisphere which might appear to exacerbate mini ENSO phase -ve momentum tendency wind-flows at the expense of the wider tropical>.extra tropical ebb and flow. Very much a blurred edge and not black and white series of response mechanisms here. I am not a forecaster per se and simply an enthusiastic diagnostic and evidence based weather researcher, but too soon I think to try and make determinant judgements on the rest of this summer as there remains uncertainty about this in my opinion. Tams
  4. 7 points
    @MattHugo -- You have some salient points in your post there, and I don't necessarily disagree, for the most part. However, I'd just caution on attempting to draw a total 1:1 relationship b/t the GWO/AAM and the resultant z500 structure, as sometimes there are inconsistencies. For example, 2006, which as I've noted many times, has been one of my primary analogs for the summer, due in part to the +QBO, weak-Nino, SSTA profile, etc. 2006 summer was a warm one for both E CONUS and UK. In terms of the particulars, June 2006 actually featured a fairly robust Nina-esque atmospheric regime, with GWO orbiting octants 1-2-3 -- that is, much more Nina-esque than this month. Yet, June 2006 featured a mid-level ridge over UK. This was likely due largely to a robust +NAO, which we don't have this June. See GWO phases here for June 2006 - GWO phase is the second column from the right. We were Nina-esque until the end of the month. 2006 6 1 -0.23 0.01 3 0.23 2006 6 2 -0.29 -0.95 1 0.99 2006 6 3 -0.54 -1.61 1 1.7 2006 6 4 -0.82 -1.7 1 1.89 2006 6 5 -1.07 -1.17 1 1.58 2006 6 6 -1.14 -0.66 2 1.32 2006 6 7 -1.21 -1.07 2 1.61 2006 6 8 -1.41 -1.31 2 1.93 2006 6 9 -1.56 -0.59 2 1.67 2006 6 10 -1.53 -0.2 2 1.54 2006 6 11 -1.57 -0.07 2 1.57 2006 6 12 -1.52 0.91 3 1.77 2006 6 13 -1.29 1.08 3 1.69 2006 6 14 -1.19 0.22 3 1.21 2006 6 15 -1.21 0.06 3 1.21 2006 6 16 -1.16 0.49 3 1.26 2006 6 17 -1.06 0.61 3 1.22 2006 6 18 -0.99 1.07 4 1.46 2006 6 19 -0.76 1.82 4 1.98 2006 6 20 -0.48 1.78 4 1.84 2006 6 21 -0.27 1.49 4 1.51 2006 6 22 -0.07 1.82 4 1.83 2006 6 23 0.24 1.71 5 1.72 2006 6 24 0.42 1.16 5 1.23 2006 6 25 0.59 1.51 5 1.62 2006 6 26 0.89 1.96 5 2.15 2006 6 27 1.21 1.28 5 1.76 2006 6 28 1.34 0.71 6 1.52 2006 6 29 1.52 1.24 6 1.96 2006 6 30 1.85 1.94 5 2.68 Here was June 2006's z500: And finally, here was the AAM equator-pole profile for 2006. June 2006 featured a modestly negative AAM [as evidenced by the above GWO]; July 2006 featured a positive AAM spike with Nino-esque GWO, and then August 2006 was very close to neutral AAM wise. So overall, summer 2006 was not an extraordinarily positive AAM summer, w/ the weak nino backdrop, yet still featured fairly warm conditions in the means for E US and UK. Thus, I think we're going to see a warming trend on both continents as the NAO neutralizes in early July, regardless of the tropical convection. Nonetheless, my confidence is certainly higher for the E CONUS being warmer than normal this summer compared to UK, though I still think the latter likely will be. Maybe we'll see a more significant AAM transport deeper in the summer, but typically in these +QBO/weak nino summers, one sees the more Nina-esque propensities in the first half [ala summer 2006]. And as delineated above, June 2006 had a more Nina-esque momentum profile than the instant year. For E CONUS interests, I think we're headed toward a warmer than normal July. Next week looks fairly warm as well in these parts.
  5. 6 points
  6. 6 points
    like i always say, issue the flood warnings now
  7. 6 points
    Decent storm today near the Cape May-Lewes Ferry. Got decimated as it neared the shoreline. Cape May Bubble strikes again. Saw some marine life. Pretty nice sunset as well
  8. 5 points
    Interesting commentray and replies. Not much to add at the moment, the overal evolution, to me, remains similar. Certainly some influence from the recent MJO/WWB but as the below animation highlights the propogation of the E'ly trades back towards 120E is gaining some traction. To me, looking ahead, the outcomes remain similar, once we progress beyond the end of June, it's likely that the N Atlantic and NW Europe pattern will often be far more trough dominated, than the other way around. Equally, it's interesting to note the last EC Monthly as well which really 'ramps up' the signal for a cyclonic first half of July with pronounced -ve MSLP anoms across the N Atlantic and into NW Europe. The hope that the more Nino profile will be maintained is still there, but to me, compared with the last few months, at least, it seems to be loosing the fight, especially with the way the SST's are setting up as well. No quick changes, but as we have just recently seen after the pronounced WWB/+AAM anoms through May, the reverse through June has certainly been unhelpfull in getting summer off the ground. While it is interesting to look back at recent years, it is, from experience, often a 50/50 bet when it comes to pattern matching to years past, but here's hoping the above discussions hold some truth and we do see an overall progression towards more sustained summer synoptics through mid-to-late summer, but, personally, I'm not seeing that at the moment, or at least not until mid-July. Late July and August remains anyone's guess... Kind regards, Matt.
  9. 5 points
    Has little relevance in terms of the winter. We've had 15 -NAO Junes since 2000. We are trending toward a negative NAO cycle, for other reasons, but that doesn't necessarily mean next winter will be -NAO.
  10. 5 points
    This is correct. I do not see much 90+ heat here if any any time in the near future. WX/PT
  11. 5 points
    Had a nice storm to end the day at the Cape May-Lewes Ferry
  12. 5 points
    Quick update... Looks like, depsite the 2 day lag, some potential influences from the MJO/WWB even though it continues, or is forecast to make little progression beyond the dateline. Quite a noteworthy spike in tendency, than compared with of late and, finally some movement of the GWO into P4, perhaps getting around to P5, but given latest predictions I wouldn't expected to get any higher than that!... What is interesting with the GFS forecast output is how over the last few days it has trended towards what the EPS was showing from back on the 16th, last available chart that I've managed to get hold of. Note that extension westward of the E'ly anoms through late June as the overall WWB eases. You can also see from the usual MJO RMM plots as well how the current MJO has just 'died' as it has entered P5, clearly in association with the interaction of the trades and with this current MJO activity site to die off within the next 5 to 7 days tops. The other few charts of interest are from Victor's site. The long-standing spike in AAM is still there, short-term, but notice the continued fall from the CFSv2 output. However, what stands out massively, is for the GEFS BC chart to suddenly 'come alive'. I'm not sure why, but this has been persistently 'off the scale' in recent weeks, but that, to me, is a noteworthy fall in global AAM looking forward through into early July and beyond. As per my last post, it looks increasingly like that the long-standing +ve AAM/Nino profile may well be about to come to an end, or at least weaken significantly than compared with recent months. . The current MJO/WWB most certainly seems to be having some influence on the downstream pattern with next week, the final week of June, set to bring a greater risk of summer-time blocking and the first heat of the summer for the UK, this has been signaled for a number of weeks now; a late June change. However, it still looks to me that any blocking regimes will be short-lived and a return to a more cyclonic pattern as we progress through July will return. The chances of this summer becoming anything special from a UK's perspective looks slimmer and slimmer by the day/week... Matt.
  13. 4 points
    I hope not too many people weren't fooled by the very warm to hot forecast maps generated by the models over this weekend. At least for the immediate NYC Metro Region, I am not at all looking for a terribly hot or much warmer than normal end of June or first half of July. WX/PT
  14. 4 points
    Today saw temperatures rise into the upper 70s and lower 80s in the Mid-Atlantic and southern New England regions. High temperatures included: Albany: 80°; Allentown: 80°; Baltimore 83°; Boston: 83°; Harrisburg: 81°; Hartford: 82°; Islip: 81°; New York City: 79°; Newark: 83°; Philadelphia: 82°; Providence: 81°; Richmond: 83°; Scranton: 78°; and, Washington, DC: 83°. Tomorrow, temperatures will likely be several degrees warmer across much of the region. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around June 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.05°C and the ENSO Region 3.4 anomaly has averaged +0.77°C. Conditions consistent with El Niño appear likely to persist through at least late June in Region 3.4.   The SOI was -42.04 today. That is the lowest figure since February 19, 2019 when the SOI was -43.61.   Today, the preliminary Arctic Oscillation (AO) figure was -0.080.   Blocking is consistent with warmth on the East Coast during the middle and latter part of summer. Hence, should blocking generally persist, the prospects of a warm or perhaps very warm second half of summer could increase.   With respect to the current month, there were 13 cases where the AO averaged -0.75 or below during the first half of June. The mean temperature for the second half of June usually fell within 1° of normal in the northern Middle Atlantic region (73.6° is normal in New York City). According to the latest guidance, the June 16-30 temperature could finish near 74.0°. During the closing week of June, parts of the Northeast could see their warmest temperatures so far this summer.   In addition, since 1950, there was only a single year that saw the AO average -1.000 or below in May and -0.500 or below in June (as appears likely in 2019): 1993. 1993 featured much above normal readings in the East during the late summer (August 15-September 15 period) and predominantly cooler than normal readings across the western third of the nation during much of the summer.   On June 21, the MJO was in Phase 6 at an amplitude of 0.638 (RMM). The June 20-adjusted amplitude was 0.641.   Since 1974 when MJO data was reported, years in which the MJO was in Phase 5 at an amplitude of 1.500 or above for at least two days, as was the case this year, were typically warmer than normal and drier than normal during the first 10 days of July. 1975 and 1985 were somewhat cooler than normal and very wet during the July 1-10 period. Some of the extended guidance is continuing to suggest a warmer and drier outcome with the warmest anomalies likely during the second half of that period. However, the most recent run of the EPS weeklies suggests a cooler first 10 days of July. For now, the base case remains a warmer outcome overall.   The base case is supported by the recent steep decline in the SOI. The SOI's sharp and dramatic decline may well mark the start of a larger process that will kick start downstream changes that will lead to a period of above to perhaps much above normal warmth in the first half of July, some relaxation in the warmth afterward, and then a very warm second half of summer (perhaps along the lines of the evolution of 1993 in August into September).   Since 1994, there have been 6 cases where the SOI fell to -35.00 or below during the June 16-30 period. Following such SOI outcomes, the July 1-15 temperature averaged approximately 3.5° above the June 16-30 figure in New York City. Based on the modeled June 16-30 outcome, that would imply that the first half of July would be among the top third warmest first halves of the month on record. In addition, 4/6 (67%) of those cases were followed by an El Niño winter (one was followed by a La Niña winter and one was followed by a neutral ENSO winter).   The implied probability of a warmer than normal June in and around New York City is currently near 50%.
  15. 4 points
  16. 4 points
  17. 4 points
    Chasing is probably not done for today. More storms coming across the Delaware Bay
  18. 4 points
  19. 4 points
  20. 4 points
  21. 4 points
  22. 3 points
    The much discussed Newfoundland/New England cold pool has warmed dramatically over the past 2 weeks -- now much less anomalous. Will be interesting to monitor to see if this will aid in the feedback of a gradually warming temperature regime in the Northeast.
  23. 3 points
  24. 3 points
    @forkyfork made an interesting post on another forum about the spring PV breakdown may have reshuffled the global pattern and he thinks we are starting a multi year -NAO episode. Any thoughts??
  25. 3 points
    Totally agree. And even though the 00Z GFS shows the heat for the first several days of July, I remember when it showed it for June 24-26th. In other words, just wait until the time-frame gets closer and the heat will be GONE. The back-up in the Atlantic with the cyclonic flow aloft and at the surface over southeast Canada is a fixture for most of the summer. Could it relax for a short time at some point in the second half of July? Yes, but then the same old pattern will reload and persist. Earlier I said 5-10 90+ days for NYC this summer but now I'm saying 1-3 of them. WX/PT
  26. 3 points
    there were 10 straight 90 degrees or higher days from 7/7-16/1993...three straight 100 degree days were in that period...it also has the hottest week in NYC weather history... Hottest seven day period... high low mean max .. 98.0 76.9 87.4 102 7/07-7/13 1993 98.4 76.3 87.4 104 7/15-7/21 1977 98.3 76.0 87.1 102 8/29-9/04 1953 95.1 78.9 87.0 .98. 8/05-8/11 1896 95.7 77.9 86.8 104 7/18-7/24 2011 94.6 79.0 86.8 .98. 7/14-7/20 2013 95.3 78.0 86.7 .99. 8/09-8/15 1988 96.6 75.1 85.9 102 8/11-8/17 1944 96.1 75.2 85.7 100 8/01-8/07 1955 95.3 75.9 85.6 103 8/04-8/10 2001 94.9 76.1 85.5 102 7/16-7/22 1980 97.3 73.6 85.4 102 7/17-7/23 1991 95.7 75.1 85.4 .98. 8/28-9/03 1973 94.1 76.7 85.4 .96. 7/12-7/18 1981 94.3 76.4 85.4 103 7/04-7/10 2010 95.4 75.1 85.3 100 7/17-7/23 1955
  27. 3 points
    Paulie Oneill is giving a weather forecast regarding a cell that popped up above the stadium. Im dyin here .LOOOl
  28. 3 points
    @NJwxguy78's home AND shorehouse getting hit hard only an hour or so apart. Now that's skill!
  29. 3 points
    @CCB! is yelling at me in hidden posts to be more positive about today. Good luck all!
  30. 3 points
  31. 3 points
    I am currently in Elmer, NJ waiting for the severe storm. Here is the small cell that passed by.
  32. 3 points
    Yikes. That area over C/SNJ in the 3000 j/kg CAPE range. Line about to plow right into it.
  33. 3 points
    Wow. Congrats again to the PHL metro area. Cleaning up so far this season. Looks like primarily just heavy rain north of TTN.
  34. 3 points
  35. 3 points
  36. 3 points
    You never know with a decent SLP to the NW & an associated warm front straddling the area, but yeah, mid-level lapse rates are/continue to be my primary concern... More so than any cloud deck inhibition to be honest, even though that only aids in the mitigation game. Some of that is burning off as we speak though. Re: poor 3k NAM mid-level forecasts... lol I'm curious to see if being in the entrance region of the ULJ provides any help with upward motion through the column With the aforementioned surface, mid-level & upper level features, bulk shear values & the overall lifted index are favorable despite the moist airmass & crap mid-level lapse rates... Essentially, IMO, the severe threat is hanging on for life, but it's not dead yet. I mean, if you want to toss the threat, more power to you. But I'd consider it worth sticking around around despite the run to run variances of the short term models. It's just ya know, weather after all. After this, I'm really looking forward to the nice weekend!
  37. 3 points
    SNJ should be rocking this afternoon. High CAPE and clearing clouds with sufficient dews should lead to severe storms this evening. Rooting for you all up north to get action
  38. 3 points
    If anyone complains about boring weather during our next drought i will stone them
  39. 3 points
    Yep, both the thunderstorms threat and blocking for next winter
  40. 3 points
    Up to 1.74" of rain so far today with moderate to heavy rain falling.
  41. 3 points
    Area just north of TTN is going to really have a tough time with flash flooding during the PM commute.
  42. 3 points
    Severe warning issued for that storm in southern Somerset/Middlesex Co.
  43. 3 points
    6.8 quake hits Japan now. Tsunami warning for Japan.
  44. 3 points
    Can't resist those sunset pics, Logan! Keep it up.
  45. 2 points
    Tuesday/Wednesday will be mid-upper 80s for most locations away from the immediate coast, and Thurs-Saturday has a shot at the first heat wave for much of NJ [inland]. The pattern overall should be warmer than normal prospectively.
  46. 2 points
    83/55 split here today. Doesn't get much better than that at this time of year, w/ dews in the 50s.
  47. 2 points
  48. 2 points
    Looking ahead to Thursday. Looks like we will finally have a decent LLJ during the daytime. Sufficient shear will come along with it. Should be a great day across the board. Anticipating a push east for a slight risk
×
×
  • Create New...