2/16/12- Morning Briefing

Morning everyone. I'm still on the verge of getting a cold, so don't expect too much over the next couple days.

Initialization Issues with 0z models...
GFS and ECMWF appear to have initialized with little or no problems.

Surface Analysis indicates the low pressure system is moving through Michigan, attached via several fronts to another jumble of low pressure systems. I'm thinking that there may be an opportunity for some severe weather if the warm front stretches out further east on the southernmost low pressure system. This opportunity may be increased further by the presence of an intersecting occluded front, warm front and cold front to make an infamous 'triple point', where some of the worst tornadoes have been recorded. I find that both these potential threat indicators will not be doing much to increase the threat as the warm front is too close to the low pressure system which then does not have enough time to bring up unstable air for strong storms.

Potential Future Storms...
There is some 'chatter' over a possible coastal storm over the next 7 days. Glancing at the NCEP ensembles gives me the feeling that this will be too far out to sea if current forecasts verified from the GFS. The ECMWF appears a tad slower and a tad weaker than the GFS for this storm as well, so I will leave the situation alone until a closer timeframe when things become easier to look at.

Notice

Hey everyone, I'm sorry for not posting any updates. I just brought back a new pet and have been introducing it around. Also, it looks like I'm on the verge of one of my rare colds. Don't expect anything big soon.
Sorry again,
-Andrew

February 14-18 Snow Event- Model Discussion (2/14/12)

Happy Valentines Day!

We re starting to see a southward shift in the models. Here's the last 4 runs of the GFS model.

You can see the trend south from earlier model runs using the color code on the bottom right. The storm we are tracking is the one going through South Missouri and Northwest Ohio. If this were to continue, cities such as Des Moines and Chicago may get in on the snowfall. That is yet to be determined, though.

However, some models are actually trending north...

CMC Model last 2 runs

The CMC Model has shifted north from it's last 12z run yesterday and now puts the system right over Chicago. I have yet to determine why and cannot this morning as I am unusually busy.

UKMET Model

Even though the CMC model is going north and the GFS is going south, the UKMET looks like it's taking neutral ground at this point. I think, however, that based on the proximity to the event occurring and model trending that I will be looking towards the GFS for guidance.

In these times of model turbulence it is important to see 0z verification to determine potential accuracy.

UKX- UKMET
NGX- NOGAPS
EMX- ECMWF

The models closest to the bottom of the image are the most accurate. Using that, we see that the ECMWF is the model to watch until hour 72, when the SREF Ensembles take over the show. The ECMWF has frames that are 24 hours in between, so it's hard to track the storm at this time. So let's see the SREF.

The 21z (0z) run of the SREF Ensembles are still split right now. And they have a right to be. While the event is only a couple days out, the models themselves are not exactly pulled together. This is the 0z SREF, which shows 2 possible paths- the CMC (North) path against the GFS (South) path. The UKMET is in neutral territory.

Here is the latest 3z (6z) SREF Ensembles. These ones have cut down on the northern path and appear to be headed for the GFS or UKMET solutions, which are the southern track and neutral territory, respectively. I have always liked using the ensembles, as a group consensus is worth more than a singular proposition.

Analogues can still come in use right now.
Here's snowfall from the March 7th, 1999 snowstorm.

This is my personal favorite, as it is using a La Nina phase for the analogue. This could very well be possible for the Midwest and Ohio Valley. I don't know about the northeast, I have to read up on it.

All in all, this storm should be very interesting. When new data comes in this afternoon, I will certainly let you know.

-Andrew

February 14-18 Possible Snow Event (Issued 2/13/12)

Sorry for the lack of posts on this storm- the models got too confusing during the time period.

The 0z and 12z ECMWF has come back with the storm phasing in this timeframe, as I had expected may happen several days ago when I mentioned how models can revert back to the old track after shifting dramatically.

Here's the 12z ECMWF hour 72. At this point, we are close enough to the timeframe of the storm that this is probably going to happen, unless something dramatically changes (which would be very unexpected).
The ECMWF is showing a large warm sector of air being thrown out ahead of the storm, leading me to assume that this will be a rain to snow event for many just south of the IL/MI/NY border lines.

Since it is close enough, I have decided to bring back the analogues.
The 'best' analogue for this storm was in an El Nino phase, so I ruled that out. The analogue I picked out here has very similar conditions to what is forecast by the GFS. Here is what the 2nd best analogue (March 4th, 1982) had in terms of snowfall.

I think these 72 hour amounts are a bit too far south, but do seem reasonable nonetheless. As of now, because I don't have time to make a forecast, I think this is what I will be banking on for right now. It is very much subject to change, as other models do also have a say in this.

Just for kicks, here's what the top analogue (the one I discounted due to the El Nino) showed for snowfall from the February 15, 1992 snowstorm.

-Andrew

Surface Analysis- 6:30 AM CST (2/13/12)

Surface Analysis indicates that much of the country is waking up to a cold morning today, with a strong high pressure system letting the cold air flow across the eastern half of country. The cold air has prompted Hard Freeze Warnings to be issued in Florida, among other cold-related weather bulletins.
There is a weather disturbance now ejecting from the CO/NM border. This system will continue to move eastward, eventually producing snow as it moves along. 2-4 inches of snow are possible in states like Missouri and Iowa, with 1-2 inches likely in Illinois and lower Wisconsin.
There are some scattered fronts and troughs across the Eastern Seaboard but nothing too major going on there.

-Andrew