Sunday, March 8, 2015

Anomalously Warm Caribbean May Foreshadow Severe Weather Season

The current state of the Caribbean waters into the southern Gulf of Mexico could foretell our upcoming severe weather season.

The above image shows sea surface temperature anomalies over the Gulf of Mexico, Caribbean, and southern Atlantic for early March. In this image, we notice a generally average to slightly warmer than average trend for the Caribbean waters, with spots of even warmer waters. Temperatures in the Gulf of Mexico are running above-normal to well-above-normal, particularly south of Louisiana.

As was stated by Storm Prediction Center forecaster Rich Thompson in his Tornado Forecasting Workshop sessions, a more plentiful severe weather season could be in store if you begin with a moist environment down in the Caribbean during the winter months, which can then transfer into the Gulf of Mexico for spring, to provide for a rich moisture source. Going solely by that, we're in a good position for a pre-established moisture source to kick off the severe weather season, best shown by the warm water temperatures from the Gulf Coast straight down to South America. It isn't the warmest water temperature swath we've ever seen, but it's notable.

Also an interesting feature is the rock-steady pool of well above-normal water temperatures in the northeast Pacific and Gulf of Alaska. If this can stay in place for the spring season, and we're able to maintain cyclogenesis in the North Pacific to carry storms into North America, it's possible we see a northwest flow-dominated severe weather season, which can feature intense events in the Midwest, Great Lakes, Ohio Valley, and Mid-Atlantic.

I'll have much more on this in my 2015 Severe Weather Season Outlook on Wednesday, March 18th.

To summarize:

- A warm Caribbean and Gulf of Mexico may be setting the stage for at least an average severe weather season.
- SST patterns off the West Coast could also allow for a severe weather focus in the North-Central and Northeast US.
- All of this will be re-evaluated in the severe weather seasonal outlook on March 18.