Sunday, January 2, 2011

More on Jackson, MS Area Tornadoes of New Years Eve

The NWS in Jackson has completed their survey of the tornadoes that took place on New Year's Eve.  It turns out that the preliminary track map that I posted yesterday evening (based solely on storm reports & radar data) wasn't too far off!  Below is a revised map based on their detailed survey data:

According to the survey, this was 1 tornado that tracked 26 miles, from 3 miles West of Terry to 4 miles Northwest of Brandon.  Maximum estimated winds were 120 mph (EF2 strength) near Byram.  The tornado was also estimated to have been approximately 1/2 mile wide at this point.  Below is an annotated map with some of the additional damage and intensity information.  Times are based on radar data (click to enlarge):

Below is the doppler radar image showing the storm when it was at or very near maximum intensity (EF2 according to the survey) and when the tornado was at maximum width (1/2 mile).  This is the same image that I posted in near real time when the event was unfolding:

Remember, the right half of the image depicts the wind motion toward and away from the radar.  The radar is located in the right center portion of the image (the "black hole" near Brandon).  Reds and oranges show wind blowing away from the radar, while the greens and blues show wind blowing toward the radar.  You can see the intense rotation as noted by the yellow circled region near Byram.

The radar estimates that the strongest winds within the circulation were blowing at approximately 128 mph at this time.  But that isn't necessarily what is going on at ground level.  You have to take the distance of the radar from the storm into account, in order to know what height above the ground level that the winds are being detected at.  In this particular case, the radar was at a distance from the storm such that the winds being examined within the circulation were at a height of about 960 feet above ground level.

By the time the storm reached the Pearl area (in the image below), it was much closer to the radar site.  At this distance the radar was estimating the wind speed within the circulation at a height of 428 feet above ground level.  By that time, the maximum winds within the circulation (as estimated by the radar at that height) were blowing at approximately 108 mph.

Below are some new photos of damage across the region, via the clarionledger newspaper in Jackson:

Damage to Woods Equipment Co. in Byram

Damage to 1st Pentecostal Church in Byram

Unknown damage near Byram

Tops of trees snapped near Byram

Damage to a home in Pearl

Power pole snapped near Pearl

Tree uprooted near Pearl

The NWS in Jackson indicated on their survey site that they'll also post damage photos "later".  I'll update this post with the images when they are available.

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