Phil

Yeah, this.

About as likely as the super niño rising from the dead.

Quite a shift in guidance regarding the tropical forcings moving into September. The WPAC gradient reverses towards the end of August, which will turn wave activity fluxes equatorward over the Northwest Subtropical Pacific. Should lead to a reversal in the pattern over the western hemispheric midlatitudes, with a NEPAC/NW US trough and a downstream central US ridge.

More like dewpoint delirium.

The 12z GFS agrees. Sticks a fork in summer just as the nice index was about to go through the roof. Or is about to, with that subsidence field returning.

It might be extreme climatologically, but still warrants a heat advisory at best. No one is going to keel over in low 90s temperatures w/ low humidity unless they're on an intentional dehydration strike or something. Also, I never invoked myself. Irrelevant. I constantly rant about the Philly NWS issuing heat warnings whenever heat indices reach 100 degrees. Same problem..silly criteria.

There's no reason to issue an excessive heat warning for this. A heat advisory, sure. Not everyone has AC up there. However, even those not acclimated to heat will handle dry, low 90s temperatures just fine so long as they're mindful.

Is this a joke? *Excessive heat warnings* for highs in the upper 80s/low 90s and lows in the upper 50s/low 60s?

Gotta wait until 2017, babes. (Technically, 2016 was probably peak).

Like clockwork, 90/70 by 925AM. That's now 19 days that've touched 90 degrees before 930AM. Since 7/13, we've only had 4 days below 90 degrees, and since 7/5, we've only had 1 low below 70 degrees, and that was just barely so. Amazing how we always find a way to blowtorch in July/August, regardless of the pattern.

Yeah, already 88/72 as of 850AM. Crap climate. Never underestimate downsloping westerly flow, especially with the Potomac River sitting at 93 degrees. #deathbydewpoint

Looks like we'll finally lose the WPAC forcing as we close out August and enter September. Both the 06z GFS and the 00z EPS both have subsidence returning there, so probably safe to predict a return to the default summer pattern at that time.

This is the type of pattern that will easily produce 90+ temperatures east of the Fall Line, along with warm overnight lows. Probably my least favorite summer pattern (trough to the west, SW flow on the front quadrant). Normals are in the mid-80s now, low-80s in ~ 10 days. Should easily finish the month at least around +4, maybe closer to +4.5.

Yeah, as in low/mid 90s instead of upper 90s/low 100s. Can't have SW flow @ 500mb here and expect cool temperatures. Maybe we get a few cool days intermixed late this week, but that primary trough axis is too far west.

DCA is more than +5 for August now. At least we fell short of our fourth consecutive 100+ high...somehow managed a bone chilling 97 degrees Tomorrow might be the first sub-95 degree day in 8 days. Gonna be close, though.

Yeah?

There's no reason to be panicking about anything. The last three summers have interestingly developed a -IOD circulation hence the somewhat eastward bias in the low frequency forcing. This is intraseasonal, though, as opposed to low frequency.

You should move to Maine or Alaska or something.

I'm just as miserable, dude. Trust me, I get it. After our warmest winter on record, we followed with our cloudiest/nastiest April/May on record, now yet another nasty summer that'll finish with 50-60 days above 90 degrees, and over 70 days with heat indices above 100 degrees. Not to mention we've had three consecutive 100+ days, could be #4 today.

Well, I'm not saying the AO matters directly here, rather that high latitude blocking (in general) will destructively interfere with the developing stratPV, and capping the PV early is always a priority in a Niña, much more-so than a Niño. Having the block center close to the pole is also preferable for opening conduits to upward mass/momentum transfer into the vortex. Niñas with raging PVs in O/N/D rarely turn out well for the PNW lowlands.

So, third straight 100+ day @ DCA. Can we go for a 4th straight tomorrow?

Except for the large # of years that were cooler than average in both August and September.

Sorry, kind of rambled on there. We want a weak strat-PV early-on in a Niña, so we definitely want to see a -NAM (-AO) during S/O/N, or at least a big block (anticyclone) somewhere in the higher latitudes (whether it be within the NPAC/EPO domain, or NATL/NAO domain, doesn't matter where) to disrupt the conduit to rapid fall/early winter vortex intensification (coupling/vertical stacking). Again, it doesn't matter where the block seems up as long as it's strong enough to perturb the PV via mass/momentum transfer during those crucial developmental stages.

A warm August would definitely be a surprise to me. A very big surprise, actually. Nothing wrong with admitting that. Mother Nature is a complicated piece of work.

Well, though the sea ice concentration doesn't have a huge impact in terms of radiation fluxes into the stratosphere, the state of the NAM itself begins to matter somewhat right about now in regards to the feedback process that drives the development of the wintertime PV/NAM. If we're talking about strat/PV influence, we'd prefer blocking/anticyclonic flow in the polar upper troposphere during the late summer/autumn, to slow down/reduce the coupling between the developing PV and the tropospheric circulation. If we (for whatever reason, of which there could be many) progress into a +NAM state during S/O/N, this can/will constructively feed back both kinematically and thermodynamically with the developing stratospheric PV. If the vortex can stack vertically, it can/will strengthen exponentially and unabatedly until bottom-up wave amplification can tilt/destabilize it sufficiently to either halt the strengthening it induce a self destruction (SSW/Wave2 response).