CAPE

There is precedent.

Yeah this is my official adjustment.

Tornado risk here with this track.

Per WPC, there is Slight risk of Excessive rainfall for eastern areas late Thursday into Friday- basically along and east of the Bay.

73 here.

Since the sun and it's heat input is the ultimate driver of the earth's climate, it makes sense to look to the tropics. We know the SSTs in the tropical Pacific (ENSO state) historically has major impacts on jet stream position and strength particularly during winter with larger air temperature differences, but there seem to be other factors at play recently. Hadley cell expansion is one possibility.

She looking pretty healthy on radar.

Might as well monitor the QBO, another index whose teleconnections to important stuff like HL blocking is nebulous at best. The experts tell us that when it trends negative heading into Fall and winter good things can happen. So, it went negative in June. Trend, friend. QBO @ 30 mb 2021 10.19 8.92 9.75 5.25 0.31 -6.93

There better be significantly less pollutants today than there were back then, with all the measures in place to reduce sources of air pollution/emissions. That said, we can still get days where the pollutants are of high enough concentrations for air quality alerts, as was the case today for some parts of the region. The air was relatively stagnant with a temperature inversion, and not much mixing for much of the day. That is conducive for haze in a hot air mass with significant water vapor content. Last week even though the upper ridge was more impressive, the lower part of the atmosphere was well mixed, and drier air tended to work in during the afternoon.

High of 90 here, with dewpoints low 70s. Pretty hot and humid. Bit of a breeze out there now.

It does. Truth is we still have plenty of particulates in the air these days. The east coast haze is usually the result of heat and humidity- plenty of water vapor and pollutants congealing, along with stagnant conditions. Pretty good cap today up around 850 mb and weak low level flow, so it cant mix out.

Definitely got the hazy skies today. High dews and not much vertical mixing.

18z NAM. Pretty similar to Euro with track/placement of heavier rains.

If iirc, a -AO is primarily correlated to colder winters (for DC), with -EPO being the next best option. For snowfall, have to look at ENSO state (and other factors) in conjunction with what's going on in the high latitudes. Not sure on the clipper thing- we had our share of those type systems in 2013-14 (and maybe the following winter) with the EPO ridge, I think? I would guess a Pac jet on steroids blasting into N. America would likely be antithetical to clippers.

We don't necessarily want a strong Nino (or Nina) here. We got lucky in 2016 with a 7-10 day moderately cold period and the odd blocking event that set up. Otherwise that would have been remembered as a wall to wall warm and mostly snowless winter.

Considering it is directly upstream, it always is a major factor. Wrt last winter, pretty easy to just say a Nina will typically not be kind to the MA with more NS dominance and weak or non existent STJ. A N shifting/stronger Pac jet, if that ends up being more of a fixture in winter going forward, may tend to modify ENSO impacts(especially weak events) and other indices that are historically correlated to cold/snow in the DC area, such as the AO phase.

I do agree with this. Everything else evolving the same way without the -AO/NAO, and it would have been a disaster. We did get unlucky with the SWE/PV disruption when the blocking shifted and the TPV lobes dug further west. That was the one time we could have had legit cold here, and instead we sat under an upper ridge with warm air aloft, while Houston froze.

lol more like one. unless you count Jonjon, and out there none of this stuff matters much. He will see 100"+ regardless.

It did some good- 12" of snow here, (or even there where you are) is perfectly respectable these days. But typically with the AO persistently negative as it was, we have a mechanism for delivery of Arctic air. Canada was so anomalously warm though due to modification from the Pacific.

Even when it snowed or I got sleet/zr here temps were marginal. Not a single temp in the teens here last winter, even with snow on the ground and perfect radiational cooling conditions. Cant recall that happening in recent memory. The only legit cold air that made in deep into the US last winter went west of us, and we got the stale moderating air from that that produced the sleety/icy period.

It's the Pac firehouse that is primarily driving lately. Barely any cold in our source region when we needed it, despite a predominately favorable AO/NAO last winter.

The only thing worth discussing at this juncture is ENSO. Looking like neutral or weak Nina is favored. Ofc ENSO state doesn't seem to matter much lately, wrt our sensible weather in winter.

Disaster