La Plata, MD F4 Tornado - 10th Anniversary

[Thunder Road]

Today marks the 10th anniversary of one of the most remarkable tornadoes in recent Mid-Atlantic history.

It had 38-mile-long path. At its widest, F1 damage covered over 1/2 mile wide. Extremely photogenic, especially as it crossed the Chesapeake Bay. Multiple-vortex and a quick mover too, 50 knots! Not to mention 4.5"-diameter hail from the parent supercell.

The storm crossed into LWX's CWA around 4:30 pm in Shenandoah County, VA, and stayed discrete all the way to Salisbury, MD, more than 3 hours later.

Truly unheard of for this region.

LWX's write-up in their archives about the event, including a multitude of pictures and other materials: http://www.erh.noaa.gov/lwx/Historic_Events/apr28-2002/laplata.htm

LWX issued 14 tornado warnings that day. (Most WFOs in the Northeast average that number in a year.)

Although SPC WW and risk area archives don't go back that far, a summary (posted below) says a Tornado Watch was issued for the region at 3:30 pm.

LWX originally rated it an F5 based on two buildings in La Plata, but Tim Marshall and his team later brought that down to F4.

http://www.nws.noaa.gov/os/assessments/pdfs/laplata.pdf

Over the bay at this point, already weakened to F1/F2.

4.5"-diameter hail in La Plata.

I'll make some maps of the event and post them here in the afternoon.

[andyhb]

Here's the synoptic setup from that day.

[audioguy3107]

Here's the skew-T from WAL that day. Numbers pretty impressive for the mid atlantic, CAPE 2658 with LI of -8.

[Thunder Road]

Here's the skew-T from WAL that day. Numbers pretty impressive for the mid atlantic, CAPE 2658 with LI of -8.

Not to mention a 0-1 km SRH of 254! Yikes!

[Buckeye05]

I remember that the survey team incorrectly rated this tornado an F5 at first due to some clean foundations. I think some pro surveyors had to step in and downgrade it due to the lack of anchor bolts.

[Hoosier]

The archives actually do go back that far. You can see all outlooks, watches, md's etc that were issued here

http://spc.noaa.gov/exper/archive/event.php?date=20020428

[vortex95]

I remember that the survey team incorrectly rated this tornado an F5 at first due to some clean foundations. I think some pro surveyors had to step in and downgrade it due to the lack of anchor bolts.

From some presentations I have seen on this tornado, it is questionable that it was even a F4. Yes, homes were removed from their foundations, but in the case presentations homes that were removed were *still* mostly intact. That's not even F3.

[andyhb]

[Buckeye05]

From some presentations I have seen on this tornado, it is questionable that it was even a F4. Yes, homes were removed from their foundations, but in the case presentations homes that were removed were *still* mostly intact. That's not even F3.

The F4 rating was mostly based an the total leveling of brick buildings downtown. It was surveyed by Tim Marshall so I trust the rating. I honestly don't see any swept, intact homes on this survey page.

http://www.erh.noaa.gov/lwx/Historic_Events/apr28-2002/laplata.htm