The National Weather Service in Jackson has rated the storm the hit just east of Brookhaven this morning an EF2 tornado with maximum winds of 120mph. While the weather today unfolded almost perfectly according to forecast I must say I am a little surprised at the strength of winds with one cell that crossed south Mississippi.

Now
I am not here to argue tornado vs straight line wind damage. Lets face
it, if your home is damaged or destroyed by winds. Who cares if it was
a tornado or not. Strong winds are strong winds!

Anyway the scenario is very interesting. It looks like a mesoscale convective vortex(MCV) formed and then moved across south Mississippi. What is an MCV you ask? Good question. I'll skip the technical "mumbo
jumbo" and get right to it. Basically, you are looking at a small
circular rotation in the atmosphere. This circulation is a smaller part
(mesoscale) of a larger storm. The MCV triggered a line of storms that produced a line of strong winds. At the far northern end of the line where the MCV was located (the comma head) there was probably enough rotation to kick off the strong winds along the path of the MCV.
Damage first started in eastern Adams county with a tree down followed
by the Lincoln county damage. Further to the east strong winds were
reported in Collins and then eastward into Jones county before the MCV weakened.

While not totally unheard of this time of the year. MCV's are more common in the hot weather months.

Much needed heavy rain will be around central Mississippi Thursday. A disturbance in the upper atmosphere will cross our area Thursday. The disturbance combined with tropical moisture will produce heavy downpours between 6AM and 1PM. The rain should move rapidly to our east by early afternoon. Cold air in the upper atmosphere could be enough to produce some small hail across south Mississippi with some of the stronger storms.

Next week is not looking so clear this evening as long range weather models are having trouble resolving long range weather. Many times I am quite comfortable with my forecast out 5-7 days but confidence is very low right now.

Forecast models are having a lot of trouble keeping track and up to date with numerous fast moving disturbances. A long line of disturbances will be crossing the area over the next week. 1 Thursday, another late Saturday with the next one due in Christmas Eve or on Christmas.

Christmas is a week away! Hard to believe! The weather pattern is shaping up to be an active one into this weekend before quieting down by Christmas Eve. The weather continues to act as it should in a La Nina year. If you missed my past blogs La Nina is the cooling of the Pacific waters. Like El Nino, La Nina affects the global weather pattern.

La Nina produces and active storm track from the western states across the Rockies to our north and up through the Ohio Valley and on to the northeast. Mild temperatures are generally in place across the South with brief but sometimes regular bouts of cold weather. While the pattern generally brings below average rainfall, the next few weeks look to be rather wet at times.

2 storms will zip across the U.S. over the next 4 days. The first will bring rain by Thursday morning with a second system bringing rain for Saturday. Like last Saturday, the second system will be followed by a brief blast of cold air. Cold high pressure will settle over the South for Christmas Eve and Christmas Day. Temperatures could drop into the 20s for Christmas Eve morning and to around freezing for Christmas morning. At this time it appears the first half of next week will be quiet weather wise. After a chilly Christmas temperatures should moderate.

Right now it looks like the only bad day for pre-Christmas travel would be Saturday.

Ingredients are coming together late Friday evening for a large storm
to form. The developing storm will grow powerful Saturday and will
bring a wide variety of weather with it to the eastern half of the
country. Here in Mississippi a good soaking rain will fall for a good
part of Saturday. It looks like we could see up to 1 inch of rain. Rain
will spread across our area from west to east Saturday morning into the
early afternoon and then fall for about 6 hours. Rain will come down
hard at times before the weather system quicklyshifts to our east during the early evening.

Much colder weather will follow the rain on Sunday with lows in the 20s Sunday and Monday nights.

Near record warmth continues and it looks like we will have 2 more days of it through Wednesday. Yes, it is unseasonably
warm and yes it is rare to be this warm for so many days in a row in
December. But it has happened before. I looked back 25 years and looked
for at least 5 days in a row with a high of 75 and lows in the 50s and
60s during the same time frame. Here is what I found. In 1998 we had a
similar warm spell from the 1st to 7th of December. In 1990 there was a warm spell from the 12 to 17th and in 1984 the last week of the year from the 26 through New Year's Eve was toasty.

I also was looking for a correlation
with these spells and La Nina. La Nina is the cooling of the Pacific
waters and usually brings a mild winter pattern to Mississippi. But in
the above mentioned years there was no La Nina in those years.

Is the currnet warm spell related to global warming? Hard to say, but given these spells have happened before there is no direct evidence to support a relation ti global warming.

El Nino is the warming of the Pacific Ocean currents. La Nina is the
opposite, the cooling of the Pacific Ocean currents. Both changes have
a profound impact on weather patterns that affect the United States. As
2007 comes to a close La Nina has strengthened and the weather across
the country is acting accordingly. Stormy out west, mild to warm in the
east with brief cold snaps. Unfortunately, La Nina usually means dry
weather for the southeast...not what we want to hear.

So don't
be surprised of you see more news stories about bad storms out west and
large snowstorms over the central states. Here in Mississippi, La Nina
brings perhaps a better chance of anice storm than a snowstorm. But with above average temperatures this winter and only brief cold snaps, the chances of a wintry storm are low. The timing of cold and moisture arriving at the same time would have to be perfect.

After seeing temps go up and down for the last week or two a major warm
spell will begin this Friday (12/7) and continue into the middle of
next week. Highs and lows will average about 15-20 degrees ABOVE
average. Now that is warm. Further, I am expecting above average temperatures for the next two weeks. That will take us through to the week before Christmas.

I
also want to mention we are on target for one of the driest years ever
here in central Mississippi. The driest year on record in Jackson was
1952 with 31.66" of rain. Right now we are at 31.34". Whatever happens
2007 looks to be a top 3 dry year. Stay tuned.