Sunday, December 23, 2012

Christmas Day Severe Weather Threat

There is a legitimate threat for severe weather on Christmas Day, something that should not be taken lightly. The Storm Prediction Center shows a slight risk of severe weather over the Gulf Coast, but probabilities of severe weather over Louisiana and Mississippi show a 30% chance of severe weather- something seen in the spring, not the winter.

The 500mb wind forecast from the NAM model on Christmas Day shows a strong storm system in Oklahoma, with winds surpassing 90 knots. Notice how the winds are also tilting to the southeast. This tilt means the storm system is negatively tilted. In a negatively tilted system, cold air is able to flow more freely aloft, meaning higher instability and higher chances for severe weather.

The 700mb winds show a very strong value of over 60 knots present over Texas and Louisiana. The presence of very high winds in the lower level jet stream only significantly increases the threat of severe weather and tornadic thunderstorms. Considering the high gradient of dewpoints, it does appear that these storms will form along a dry line (high gradient of moisture). Drylines are commonly the focus of severe storms in the spring, so we could very well be dealing with spring-type severe weather.

Such a situation needs to be closely monitored, as, if these forecasts verify, lives and property could be threatened.


1 comment:

Anonymous said...

Living in southern VA sucks... We almost never get any winter precipitation. I hope that PV obbliterates itself. :)