Philip Wiegand

What can Chicago do that LA couldn’t?

The larger scale factors responsible for the anemic 4CH this summer are technically still present in early August. I’ll wager anomalous height rises end up in W-Canada/Interior NW US before the ISM/building IO MJO retake control.

The stars are aligning on a seasonal and subseasonal scale for this year’s Atlantic Hurricane Season to be pretty underwhelming compared to normal thru early-mid Sep ish, while also finishing quite strong late Sep into Oct.

Current SSTa pattern, MJO/S2S variability, & analogs all support this.

I updated the PolarWx model forecasts vs. ERA5 records map to include 2024 in the ERA5 record period (1950-2024, previous maps' period of record was 1950-2023).

The upcoming East US ridge will set near-record annual maximum geopotential heights... the previous record was set in June of last year.

The Trump-era Dem base resembles the Obama-era GOP base: highly engaged & higher income that vote at higher rates during midterm elections. Dems erred thinking 2022 over-performance would carry into 2024 because it wasn’t driven by Dobbs/Democracy as much as the nature of the electorate itself.

Time series of the mean vortex strength for each December from 1979 to 2024, and its variability within that month.

The Arctic stratospheric polar vortex during December 2024, as measured by the zonal wind at 10 hPa & 60°N, was the third strongest on record for the month since 1979, marginally behind 2015 & 1980, and similar to 2013, per NASA GEOS/MERRA-2 analyses.

ozonewatch.gsfc.nasa.gov/meteorology/...

9477: Christmas Shoes.

(1/2) After its weakest Sept wind speeds since 1979, the Arctic stratospheric #polarvortex is making up for lost time and looks to rapidly intensify into early December.

This image will be in the NASA calendar for 2025. One of the most detailed red sprites I have captured. Plasma physics is both beautiful and wild. Available as a print on my website for those who'd like to support my work

Land, mountains and tracks of storms are revealed from maximum wind gust speed over a 44 year-long atmosphere simulation at 9km resolution done at @ECMWF for @EERIE_Project #EERIE
#30daymapchallenge

High rise living is underrated, man. Live on the 29th floor now and the views are 🔥 Esp for Aurora viewing.

Oh wow, I see the OMI MJO index has been extended back to 1940 using ERA-5 👀

www.psl.noaa.gov/mjo/mjoindex...

The colors!

How well can global ensemble forecasts predict tropical cyclones in the southwest Indian Ocean? The southwest Indian Ocean (SWIO) recently experienced its most active, costliest and deadliest cyclone season on record. The anticipation and forecasting of tropical cyclones are crucial to preparin....

How well can global ensemble forecasts predict #TropicalCyclones in the SW Indian Ocean? How have forecasts improved? How does the MJO affect cyclones and their forecasts? 🌀

We evaluated 10 years of forecasts from ECMWF & UK Met Office to find out: rmets.onlinelibrary.wiley.com/doi/full/10....

The eastern Mediterranean heating and the tendency for the East Asian monsoon to break down and spread into IO/west Pac modes can both support the wave sourcing you need over Eurasia to initiate the +CGT pattern.

So yeah, without getting too hype (is that even possible on Bluesky? lol) I would say this is the most threatening summer we've had in a while for the Midwest to Northeast heat dome. And the background spatial SSTa and pattern are also supportive.

Interesting. Like soil moisture feedback(s) or something more external/tropical forcing related?

Big heat in June w/ developing niña tends to be a warning sign for a blowtorch summer. See 2010 and 1988. And 1954 to some extent.

Skies cleared around ~ 1AM, and holy shieeet. Absolutely breathtaking..I might’ve shed a tear or two.

It's so beautiful, I might cry.

I have been waiting SO LONG for this to be national, and now it has!

www.wpc.ncep.noaa.gov/heatrisk

You border on clairvoyant sometimes. Very well done.

Check out the latest Polar Vortex Blog post on reasons why the minor #SSW wasn't able to quite make it to major status... and chances of that changing in the next couple of weeks! www.climate.gov/news-feature...

WPC's Probabilistic WSSI (WSSI-P) went operational today!

Link to the webpage: wpc.ncep.noaa.gov/wwd/wssi/pro...

Link to the user guide: wpc.ncep.noaa.gov/wwd/wssi/WSS...

Shout out to Dr. Josh Kastman & Dr. Dana Tobin for the development of this product.

Synoptic wave train will transport momentum into the Pacific Jet.

The "jet extension" is not unusual (counter to all the hyperbole out there about it), and its behavior is not entirely based on the descending East Asian High either. The diabatic response from the Niño forcing/structure and the subtropical wave train are also adding momentum to the jet, too.

GEFS & ECMWF subseasonal forecasts now very confident in a notably weakened polar vortex by early January, with a substantial risk of a major sudden stratospheric warming. Even if a major SSW does not occur, such a weakened vortex would likely have some tropospheric effects.

You don't get a classic gill-response like this often in the tropics like what we're seeing around Dec-8th. It's a thing of beauty to see theoretical tropical meteorology pop up in the real-world.

Keep a level-head going forward as we get inundated with promises of a big pattern change, severe Arctic cold, etc. The grift is simple: forecast extreme cold all the time so that when it does happen to occur, the forecaster basks in the accolades.