CAPE

LOL last winter. The antithesis. We should probably get used to it.

Epic HL blocking for the entire winter. It seemingly occurred so easily...effortless. It's like a fantasy now- something that simply cannot occur. Extinct.

Mount Holly AFD on the severe threat for Wed- Kind of a mixed bag in terms of environmental parameters. Temperatures will no doubt be on the hot side, but MLCAPE values are somewhat of a question mark due to uncertainty in how much mixing will occur. While MLCAPE will certainly be sufficient for convection, there is disagreement on whether values will be "good" or "great". If dew points mix down into the 60s, convection may struggle to develop or weaken as it approaches, as some of the CAMs suggest. However, if dew points remain in the 70s, instability will be greater. So mesoanalysis with regards to the dew points will be important. In terms of shear, deep layer flow will increase as the shortwave approaches. Bulk shear has trended down a bit, and may only be in the range of 25 to 30 kt, whereas yesterday 35 kt or slightly greater looked achievable. SRH parameters also do not look as impressive, with shear profiles looking increasingly unidirectional, not to mention the generally weak low level flow. While an isolated tornado cannot be ruled out, it is a low risk, and the better chance for that will probably be to our north where SRH is better. Given warm low levels, modest mid-level lapse rates (around 6C/km), and likelihood for linear convective organization, severe hail is also a fairly low risk. So the main hazard is going to be damaging wind. Shear values, while not great, should be sufficient for some organized multicell convection, with some of the CAMs suggesting an MCS is possible. Difficult to pin down where exactly the greatest threat is, with still a fairly wide spread in CAM solutions, hence the continued broad-brushed slight risk area in the SWODY2. Would generally favor areas further west and south (E PA and Delmarva) for the greatest chance of severe weather since they should have the best instability and since diurnal timing looks most favorable there, but a risk exists everywhere.

Just looking back at 2017-18, the QBO(u30) was moving into the negative phase in Fall and stayed significantly negative through the winter. That winter was decent wrt cold outbreaks/anomalous cold, at least for Dec and Jan. I think that was technically a moderate Nina, but the QBO influence on the tendency for cold that winter may have been real. The previous winter, also a Nina, QBO was moving into positive territory and stayed positive, and it was more the typical Nina eastern US torch. Again this is cherry picking one index in isolation, and so it is always difficult to determine the actual impact. The character of the Nina events were quite different between those 2 winters.

Probably not worth doing any reanalysis at this point, but maybe he included 'cold' neutral years as well as weak Ninas. The sensible impact of the QBO generally seems nebulous, unreliable, and likely gets overwhelmed by other factors in reality. Looking at the 30mb trends, it also appears to be moving in the "wrong" direction currently.

Here it is- From DT at WxRisk.. The context is QBO values from -10 to -20 for DJF.

Yes in general, but I am pretty sure I saw somewhere that during a weak Nina, a significantly negative QBO for the winter months mitigated the usual warm departures for the eastern US. I will see if I can find it. Either way, it doesn't look good wrt the QBO, as it appears it will be heading into positive territory going forward.

Most guidance seems to favor a cold neutral or a weak Nina at this point. NOAA did issue an official La Nina watch a few days back, with a 50-55% chance for fall and winter. Probably a decent baseline to start with when you start digging into the historical data and analogs. QBO looks like it may have hit its negative peak and is heading back towards neutral. If that trend continues into fall that's not a good sign. Pretty sure there is a correlation between a significantly negative QBO during the winter months, and colder temps for the eastern US during a weak Nina.

Now is the time for optimism. We get to be all wide-eyed and dopey, trying to convince ourselves that winter really could bring the goods. These are good times. This period will last until about mid November, after which the writing will be on the wall, all hope will be lost, and all that will be left is the race to the Panic Room to get a luxury suite at the Reaper Resort before they are all taken.

We can get good outcomes in a Nina, even without a -NAO, which is generally not favored in a Nina winter. I would not expect a particularly snowy winter, but the 2 most recent Nina winters did produce some decent snow, relatively speaking, including big snow events for the coastal areas of the MA and NE. Nina winters can be especially frustrating for the MA, but not an automatic shutout by any means. If the timing had been a tad different, this could have been a more memorable period for a larger area.

We only care about the NAO during the winter, so this historical series gives you a good idea of the long term values. NAO has been predominately in the +phase during the winter months over the last 50 years, with generally more instances of strongly positive episodes in winter compared to prior periods. With the recent unfavorable trends in the Pacific patterns during winter, we might be phucked in the MA for awhile. Go north. None of this stuff matters much relative to cold and snow up in NH.

Is something like that even meteorologically possible anymore?

Yeah it looks like we are going to have a weak Nina or a cold neutral during winter at this juncture. This is recent stuff, from a few days ago- https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-cpc_plume

^Easy to imagine how this will go. That EPAC ridge/downstream trough position looks precarious.. but a monster -NAO will save us this time! I wont bother posting it because it sucks beyond words, but the CanSIPS has the h5 look that will probably be much closer to reality, based on our recent run.

CFS has been on a "good" run lately with looks like these. No qualifiers necessary. We all know the deal with long range climate models.

Lets get this (pity) party started.

You have had like 10" in the last month lol. How are the skeeters there?

1.68" total here, mostly from the initial round. I guess most of the heavy stuff around midnight moved to the SW of here.

I love the continuous low rumbling thunder after the main show moves through, esp at night. Relaxing. I was done drinking, but just poured another glass of wine.

Nothing severe here. Some impressive T&L and wind. Heavy rain is what I was after, and I got that. 1.25" and it seems to be winding down now. Looks like some scattered stuff yet to move through, and maybe a round 2 later per radar. If not, I'm good with this. No sprinkler for a few days, maybe longer if the late week coastal deal delivers.

Wind is impressive right now. It can stop right there. Too many trees.

I know the feeling. Been almost a month here. This one is rocking pretty good now.

Wicked lightning. Scared my ass back inside.

Im headed out to the end of my driveway