Sunday, October 14, 2018

Late October Nor'easter?

Hello everyone!

I'm seeing a few twitter accounts bumping their chest about the probability of a late October Nor'easter. The Bering Sea Rule had this probability back on October 7th.

I've actually been watching the models for the past couple of days.

12z run of 10OCT18

The next day had a system in the Northern Gulf just begging to hit the SE and move NE...

Compare that to what the BSR had on the 6th!

We are still a tad early for the East Asia Rule, but the models show the potential is there. The first graphic is from the EAR map page for purposes of the overlay.

Here is the Euro from yesterday's 00z run.

A few GFS options...

12z 12OCT18

00z 14OCT18

06z 14OCT18

00z 13OCT18 CMC just missed the connection to bring it up the coast...

How about the daily Southern Oscillation Index method? At the beginning of the month we saw a spike in both 3 day 20pt and one day 10pt...

Day 24 and day 25 of the 10pt rise...ummm....look familiar? Wow?!

Look at the lower heights over the SE on day 25 via my 20pt composites...

So, as you can see, the potential for a Nor'easter has been teleconnected for a few days via OFM.

Monday, October 1, 2018

Early October Severe Weather

Hello all,

Something that I have done for quite a few years now is utilize the OrganicForecasting method, or OFM, to predict severe weather.  Below you will find the composite of SPC high & medium risk days during a neutral fall seasons between 1991-2016.

Large trough in the lee of the Rockies and Western Plains with a anomalous ridge centered over Montreal, Canada.

The BSR website showed the same depiction. Trough West with SW Flow aloft an East Ridge with a hint of NE trough.

Next up is the daily Southern Oscillation Index. The composite below is for day 14 after a 20pt drop of three days centered on 22SEP18.

With day 0 on the 23rd, I get this with my spreadsheet...

Now, the composites for Days 14-16...

Day 16 gets muted because immediately following, we had a rise with day 0 being the 26th of September.

Now, look at the EAR depiction...

A trough west and ridging East with nice vorticity moving from Texas into the Tennessee Valley.

Latest modeling...

01OCT18 12z GFS

00z 01OCT18 ECMWF

So, I will leave you with how various aspects of OFM showed the signals of severe weather and can be an asset to a forecaster.