What an awful year for storms. The worst, probably ever. The air has this constant ice-cube-like tint. Call it natural or whatever, I think it's a reason for the clouds.
Check out this strong +PNA which you usually don't see in La Nina, 52-46-2 (Nino-Neutral-Nina). Then the NAO is positive and this whole evolution is really developing-El Nino-like http://mp1.met.psu.edu/~fxg1/ENSHGTAVGNH_18z/ensloopmref.html
The upper midwest one's aren't that impressive. -50 in Chicago? Big deal. I bet the further south has some better extremes. I bet the western 1/3 of the country has some better extremes.
Yeah, not a big deal. More -PNA duality than anything else. Surface SST trend doesn't necessarily correlate to North Pacific +PNA, although sometimes shown on models. Easy 3-5 day bias-correction I think
There's been two substantial anomalies in April and May. On Feb 21, 2018 when Washington DC had 500mb heights of 591dm, breaking its old record of 583, there was a major PV in this area.
Blizzard of 93 conditions have been building as a potential energy over the south part of Greenland for the last few months and years. Not really related, but a cool point. I can see this potential energy hitting the northeast in a few years as either a hurricane or storm.
This means subsurface temps in the central region will continue cooling, which probably means the events remains Weak or goes back to Neutral in the Fall.
Some +3> subsurface anomalies are getting close to the surface and Nino 3.4 has made switch to positive. Maybe in a few weeks.. AMO should start to warm soon, wonder if this will create a sea-saw effect with ENSO (spurring Nino). Medium term models are La Ninaish for the Hemisphere.