Also view here: http://aeroweather.org/2012/02/21/incredible-differences-between-the-euro-and-gfs-models-for-friday-storm/

Good Evening,

There looks to be a potent rain making storm on Friday, but the way it is being transpired on the EURO vs. GFS models is quite remarkable. Regardless of which model is right, do not expect any frozen precipitation out of this storm because it is simply too warm and the pattern is not favorable for snow.

Lets first look at what each model is showing in regards to the actual storm itself for Friday. First thing we will do is look at the 12z EURO from today:

The 12z EURO today has a strong low pressure system just North of NYC around 96 hours. What the EURO does it phase a cluster of short waves scattered in the Southeast and Midwest and blows this up into a large rainstorm along the coast with high winds, near tropical storm force.

This image is taken from Wunderground to show the incredible rainfall rates the 12z EURO is outputting for our area Friday night into Saturday. VERY heavy rainfall from D.C. to the entire half of Eastern PA and into NJ. If you look closely you can see where the low pressure system is located, right in NEPA.

That folks is some serious rain in a short period of time which would definitely cause flash flooding issues for some.

Now want to see the strange part?

The GFS has no where near this solution. Sure it still brings rain but definitely not as much.

18z GFS

The 18z GFS from today is keeping our Northern and Southern streams separate. The Northern energy brings to us some rainfall, light amounts, while the Southern piece slides off the Southeastern coast. GFS also holds back a short-wave in Central Mexico and tracks it into the Gulf, while the EURO already has this short-wave located near Louisiana. Lets get a better look at this.

12z EURO 500mb at 84 hours

If we take a look at the 500mb maps from the EURO at 84 hours we notice 3 things.

1. Look how entrenched the trough is into the Southeast. It gets as far South as Eastern Texas and Louisiana!! The Northern stream(s) in the Mid-west dig into the South and eventually phase to develop a powerful low pressure system. There is plenty of tilt for the storm to come up inland and hammer us with rain/wind.

2. 50/50 low is located near Nova Scotia

3. The GOM (Gulf of Mexico) is open for business and provides this storm with PLENTY of moisture as there is a High Pressure system located east of Florida.

12z GFS 500mb at 84 hours

One thing you can clearly differentiate between the GFS and the EURO is where the trough is located. Not nearly as entrenched on the GFS as it is on the EURO. You can see where I circled Louisiana is where the EURO has the trough located. Another important feature is the short-wave in Central Mexico. The GFS holds this energy back while the EURO ejects this out much quicker and gets it caught in its trough.

Which Model is Correct? 

The EURO does not have much support with the other models. The GGEM and NAM look like the GFS for the most part. It will be interesting to see tonight or tomorrow afternoon where the models start trending towards.

12z GGEM:

The 12z Canadian already has the northern energy of the storm to our Northeast and has the southern piece moving out to sea, not effecting us.

My thinking at the moment is the GFS is right. The EURO solutions seems too extreme for my liking and it is does not have much support. Usually the EURO holds energy back but in this case it is not doing so, which is another reason to believe the EURO could be right. Our NAO and AO are still positive and the PNA is neutral. I do not see how the EURO digs in the Northern stream that far south. To get a storm of that magnitude you really have to get all those short-waves to dig in South at the same time and phase at the right time.

IF the EURO is right…big IF…we could be dealing with a crazy wind storm for the coast and New England. Below are the winds per 12z EURO.

Tropical storm force winds? Good thing our trees are still bare!

Hope everyone has a great night!

-Frank