Wednesday, March 12, 2014

March 20-24 Potential Storm System

I'm watching out for a potential storm system around the March 20-24 timeframe.

There is a rule, well explained by Joe Renken, that states a weather phenomenon in East Asia will be reciprocated in the United States 6-10 days later. This means that if there is a storm system in Japan on a certain day, we can expect a storm in the US 6-10 days after that. The same goes for high pressure and warm weather. Using the image above, we can expect a storm in the US 6-10 days after March 14th, which would bring us to a March 20-24 storm. 

The storm looks pretty healthy in this model projection, which could also mean we see some active weather, both in terms of severe and wintry weather. It's still too far out to tell who could get hit, but considering we'll be seeing the Madden-Julian Oscillation in Phase 2 around this timeframe, I would keep an eye out for severe weather.

(The following is copied from the March 4th post)

Paul Roundy
Shown above is a chart of six different types of outgoing long wave radiation (OLR) anomalies. We want to focus on the middle panel of the left-hand side, where it says MJO OLR anomaly on February 16, 2014. On February 16, 2014, we saw negative OLR anomalies just south and east of the subcontinent of India. This location of the -OLR anomalies (which indicate enhanced tropical convection) tells us the Madden-Julian Oscillation was in Phase 2, out of its 8 possible phases. Check out the severe weather event that occurred just four days later, on February 20, 2014.

On February 20, 2014, we saw a large-scale severe weather outbreak, as the chart of storm reports from the Storm Prediction Center shows above. The outbreak was primarily a damaging wind event, as you can see by the large swath of blues across Tennessee and Kentucky, just to name a few of the many affected states. However, we also saw a handful of tornado reports. The fact of the matter is, this severe weather event and the MJO entering Phase 2 are not coincidence. They are correlated with one another. See the AMS (American Meteorological Society) article below:

The Madden–Julian oscillation (MJO) has been linked to weather variability in the midlatitudes via its associated overturning circulations and Rossby wave trains that redistribute the thermal and mass fields at higher latitudes. This work examines the relationship between the MJO and violent tornado outbreaks in the United States. A census of events shows that violent tornado outbreaks during March–April–May (MAM) are more than twice as frequent during phase 2 of the Real-time Multivariate MJO (RMM) index as during other phases or when the MJO was deemed inactive.

If you didn't get what this was saying, don't worry. Basically, it tells us that when the MJO is in Phase 2 during March, April and May, or when we see enhanced convection south and southeast of India, we tend to see the chances of a violent tornado outbreak skyrocket in comparison to the nonactive MJO, or the MJO in other phases. While the February 20th event wasn't exactly a tornado outbreak, it was a severe weather event, and this has me concerned for mid-March.

Let's take a look at the forecasted OLR anomalies for March 12, 2014. Once again, we'll look towards the panel labeled MJO OLR Anomaly. If we look at the forecast by Paul Roundy above, we can see very deep negative OLR anomalies placed just south and southeast of India. These blues are far deeper than what we saw on February 16, meaning that this Phase 2 MJO event could be even stronger, and thus the severe weather event would be even stronger as well. Going by the LRC we discussed above, as well as the AMS document analyzed here, I am concerned that we will see a potentially significant severe weather outbreak for the mid-March period. Because there could be a lag period between the MJO Phase 2 event and the severe weather event of about 4 days, like we saw with the February event, I'll make a tentative timeframe of March 13-18 for a potential severe weather outbreak. This one has me worried, and while you should not be worried yet, it's something to watch out for in the future.

(End copied post)

If we come back to Paul Roundy's forecast and look at the MJO OLR Anomaly panel, it looks like the placement for Phase 2 anomalies has been pushed back to March 16, which would put the possible severe weather threat either just before or during this potential storm system. Lots of things to watch here.



Anonymous said...

would the Chicago area be impacted by this? I love severe weather and i hope so.

Anonymous said...

Once again, thank you Andrew for doing your job so very well. Please keep us informed about this one.
Thank you.

Anonymous said...

I prey it fizzles out, I do not want this at all! Rain, sure some, I do not want to be drowned in it however.
Thank you Andrew for all you do, I do not want to seem like a crazy person always complaining which seems as if that is all I've done this winter, I'm really not that way. But then this winter has not been normal either.
Oh my God for a warm beach!

Anonymous said...

Will you make an official severe weather 2014 forecast (w/maps, etc.) like you have in previous years? Thank you so much for the info you give on the blog!

Anonymous said...

Andrew, do you think the GOM is too cool to bring in sufficient instability for severe weather?