*HUGE* Snowstorm In The Works for Midwest, Northeast??

12z ECMWF Hour 216

The 12z ECMWF is showing a very strong storm in the Ohio Valley at Hour 216 of its latest 12z run. Current indications are that this low could be as strong as a 992 millibar storm system (extremely low, for those who do not know). In the image, we are seeing a deep arctic outbreak behind the system, with a warm sector of air being pulled north, making for a potential severe weather threat.

The GFS has been showing this system a lot recently. Something I have learned is that when a model starts to trend with a storm, it usually means something is looking important in the model.

0z GGEM Hour 240

Something else I've learned is that when multiple models start showing a storm, it also means something may be bound to happen.

The NAO will be something to watch as well.

The areas I have circled is the timeframe for the storm. Notice how the NCEP and ESRL/PSD differ on the storm. Personally, I am wanting to go with the ESRL/PSD, as the NCEP is basically just the GFS/GFS ENS. I don't exactly know what the PSD uses, but it appears that there is definitely some different algorithms than what the NCEP uses, as shown in the difference of the forecasts.

Courtesy ESRL

As seen, a -NAO brings a cold and snowy pattern over the northeast as a Greenland Block forms (high pressure over the Greenland region). The opposite happens during a +NAO.

PSD Ensemble 500mb Spaghetti Hour 288

PSD Ensemble 500mb Spaghetti Hour 312

The PSD Ensemble members are also showing this storm, which to me is a big boost to confidence. Again, I don't know what the PSD uses, but it is different from the NCEP. The PSD sees the storm impacting the Great Lakes/Midwest region, but then carries the storm into the Northeast, whereas the ECMWF brings the storm system into the Canada. At the same time, both the PSD/ECMWF are very similar to their solutions to the storm system. Again, very encouraging.


Some reminders about this storm:
•It is still in the very long range, and thus subject to major change.
•This is in no way set in stone.
•Snowfall amounts are widely varied run-to-run of GFS.
•PSD/ECMWF combination is a very good sign.

Any questions can be asked below.
~Andrew