Charleston Weather » tornado watch 789

Tornado watch canceled; threat ends

Jared Smith — Thu, 03 Dec 2009 03:11:01 +0000

The Tornado Watch which has been with us for most of the afternoon — and stuck around a little longer than anticipated — has finally been dropped for the area.

We were very fortunate that the severe weather outbreak that had been predicted for this afternoon did not play out. One major factor was the lack of sunshine — because the clouds hung around, this kept a lid on the most explosive convection. Another factor was timing; storms did not begin to reintensify until they were largely offshore. We did notice the squall line falter and then pick up just before it pushed offshore, prompting a fairly long period where the Charleston area was warned for severe weather. After pushing offshore, very distinct rotations in the cells developed and are now moving ashore in the Grand Strand and into southeast North Carolina.

Flooding still persists throughout the region. Downtown streets, which have been turned to rivers twice in 12 hours, will need some time to clear out — the lowering tides will help. There’s also reports of standing water in Goose Creek, Moncks Corner, and North Charleston. If you encounter standing water, please do not attempt to cross — it’s hard to judge the depth of water during the day, and it’s nearly impossible at night.

Winds will remain strong through midday Thursday on the lakes; a Lake Wind Advisory continues for Lake Moultrie until noon. Small craft are also urged to use caution during the day Thursday. Gale warnings are still up until 5am for waters out 20 nm.

Here’s looking toward a much calmer and drier Thursday. We might see some rain peek back into the forecast Friday night; still tough to pin that one down, though.

Tornado Watch extended to 11 PM

Jared Smith — Thu, 03 Dec 2009 01:47:36 +0000

NWS has extended Tornado Watch 789, previously scheduled to expire at 9 PM, to 11 PM. The main line of storms is about through Charleston now, but there seems to be some activity kicking up behind it — better safe than sorry. After these last few rounds of activity clear, I suspect the watch will be dropped, especially as the highest probability of tornadic activity has moved northeast into the Grand Strand and eastern North Carolina. Will continue to watch…

Tornado Watch 789 until 9 PM

Jared Smith — Wed, 02 Dec 2009 19:24:48 +0000

It’s official, and about an hour before I thought: the Charleston area — and indeed, all of eastern SC — is now under a tornado watch. Primary threats cited in the watch discussion include damaging winds in excess of 70 MPH, half-inch sized hail, frequent and dangerous lightning, and of course tornadoes. The discussion in full:

Tornadoes…hail to 0.5 inch in diameter…thunderstorm wind
gusts to 70 mph…and dangerous lightning are possible in these
areas.

The Tornado Watch area is approximately along and 80 statute
miles either side of a line from 55 miles west southwest of
Savannah Georgia to 45 miles east northeast of Orangeburg South
Carolina. For a complete depiction of the watch see the
associated watch outline update (wous64 kwns wou9).

Remember…a Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

Other watch information…continue…ww 788…

Discussion…a mesolow/MCV in central GA will track newd along a
retreating warm front into central SC through the afternoon…and
ongoing pre-frontal storms will continue to spread newd over se GA
into srn SC. The moist and weakly unstable warm sector will surge
nwd across SC in advance of the low…while low-mid level vertical
shear will remain quite favorable for embedded supercells capable of
producing a few tornadoes and damaging winds.

Storms in southern Georgia have been kicking up a lot of lightning this afternoon, and as I write this, there are two active tornado warnings there. This is definitely something to watch closely as the afternoon progresses and we get into that rush hour time.

For the record, the time of next high tide is around 7:30. That is expected to be a lower high tide, forecasted at 5.15 feet; however, any rapid rainfall on top of an already soaked Downtown could once again put streets underwater this evening. RADAR is not estimating the same rainfall rates out of the Georgia storms as we saw this morning; however, anything above half an inch per hour could prove problematic for an already overwhelmed drainage system.