Charleston Weather » Forecast

Flooding bullet dodged; rain to ramp back up this afternoon

Jared Smith — Tue, 15 Dec 2009 14:03:41 +0000

We got a reprieve this morning from what could have been quite a nasty rain event — the heaviest rain pushed offshore well before 3am and has broken a bit, allowing NWS to lift the Flash Flood Watch. The rain respite is welcomed this morning, with even some sun breaking through the clouds, but the next wave of energy will move in from the southwest this afternoon, bringing back more showers and some isolated thunderstorms. The heaviest rainfall is expected to remain in southern Georgia, so no widespread flood event is expected. Temperatures will reach the low 70s before the front pushes through — but don’t let the jackets stray too far. We’re back into the mid 50s for highs tomorrow, with abundant sunshine.

Rain, potential flooding Tuesday morning

Jared Smith — Tue, 15 Dec 2009 02:40:23 +0000

Our wetter-than-average December will continue through Tuesday — another several inches of rain are expected during the day Tuesday as another system pushes through the area. There are some concerns on the timing of the system — we could yet again see heavy rain coinciding with a high tide in downtown Charleston tomorrow morning. (High tide occurs just after 7am.) Thus, a Flash Flood Watch is in effect for Charleston County — primarily targeted at those areas of downtown that flood — through the morning hours. If your commute takes you through downtown, be careful of areas of standing water and don’t attempt to drive through them.

We also have a shot at thunderstorms during the day; fortunately, conditions are not expected to be favorable for severe weather. Some severe weather, including tornadoes, has been observed in Georgia, but that activity is not expected to be a factor into the Charleston area. If conditions change, you’ll see an update on @chswx with further explanation here. Try to stay dry tomorrow!

As messy as advertised, with the brunt yet to come

Jared Smith — Wed, 02 Dec 2009 14:40:04 +0000

The flooding situation has been as messy as advertised this morning. NWS just reported that the high tide at Charleston Harbor this morning was 7.75 feet — well beyond the point where coastal flooding begins even without rain (typically 7 feet).

Traffic into downtown Charleston is nearly impossible. The Crosstown is closed and it’s not likely to reopen for a little while. Stalled cars litter the streets-turned-rivers downtown. Josh Marthers at WCBD captures the flooding situation well. I also highly recommend watching traffic tweets and pictures (and there are some good ones) on Collecta.

And as bad as this morning was, we haven’t seen the worst of it. This morning’s Day 1 Convective Outlook from the Storm Prediction Center continues the “slight risk” for severe weather in Charleston, and this could be upgraded to a “moderate risk” later today, especially if any sunshine peeks through and adds more fuel to the fire. The storm system which is expected to wreak havoc on us later this evening has already dropped several tornadoes in the Florida panhandle, and there is a good possibility we may see at least one or two tornadic cells later today in the Lowcountry. Straight-line damaging winds continue to be the primary threat from this system, though.

There’s a good shot that we’ll have a tornado watch in effect by 3PM today. Keep an eye to Twitter as the day progresses with updates from NWS and SPC. We’ll announce watches and warnings there as they happen.

Wednesday: Slight risk of severe weather, high probability of damaging winds

Jared Smith — Wed, 02 Dec 2009 06:17:08 +0000

The Storm Prediction Center has just issued its Day 1 Convective Outlook, placing the Charleston area in a slight risk for severe weather. Currently, forecasters are pegging the severe event to take place in the late afternoon and into the evening hours. Primary threats are widespread damaging winds as well as the possibility of tornadoes, especially along the coastal regions.

Currently, this is the thinking (or something like it) on Wednesday’s event:

3AM – midday: Heavy rain with embedded thunderstorms associated with a warm front will soak the Lowcountry. The timing of the rain will line up with an already abnormally high tide at 7am. Enhanced with a brisk onshore flow, coastal areas including downtown Charleston could see potentially significant flooding. A Coastal Flood Warning goes into effect at 4am through 11am.
Midday – ~2-3 PM: Break in the action as the warm front lifts north, but before the cold front’s squall line reaches the coast. There’s a possibility that the sun may come out during this time; any sunshine could significantly destabilize the atmosphere further and thus enhance the intensity of severe weather.
3 PM – Evening: Cold front makes its move on the Lowcountry. Squally thunderstorms with strong, damaging wind likely. Supercells also are a possibility; those storms can contain downbursts and tornadoes. Heavy rain also is expected, though the flood threat is not expected to be as pronounced in the evening. Activity will likely continue after sunset; be especially aware of rapidly changing conditions after dark because it will be much harder to see what’s happening.
Thursday: Conditions gradually abate themselves as the front moves through; rain tapers off through Thursday.

The takeaway: The morning and afternoon commutes will likely be quite nasty. Allow extra time during your commute, and if you encounter a flooded area downtown in the morning, turn around! It takes relatively little water to stall out a vehicle. Streets such as Rutledge and Ashley Avenues, Jonathan Lucas, Bee Street, the Crosstown, East Bay Street, Market Street, and others could prove impassable. Have alternate routes ready to go. Other coastal communities, including Folly Beach and Isle of Palms, may also see significant flooding problems in the morning.

Keep an eye here or to @chswx for updates throughout the day.

Eyes on Ida, impacts on Charleston

Jared Smith — Mon, 09 Nov 2009 20:24:38 +0000

Tropical Storm Ida is on its way to an early morning landfall on the Gulf Coast. As of the 1PM advisory, Ida’s packing 70 MPH winds — a generous estimate, as the storm is being sheared off from the southwest and is in cooler waters. Ida’s slowly beginning to lose its tropical characteristics, too — a condition that will accelerate as it is absorbed into a frontal system tomorrow. While Ida itself will wind down, the interaction of the storm’s low pressure center and a high pressure system to the north (which brought us beautiful weather for the weekend) is creating a tight pressure gradient, which will bring gusty winds to much of the Southeast, including Charleston. The winds will be primarily out of the east and southeast, so there is concern for elevated tides and choppy waters. Small craft advisories are in force and will likely prevail through the next several days.

The forecast is still a bit tricky on this, but for now, expect some showers to start after midnight, with a buildup of rain during the day Tuesday. If the forecast holds, the rain will gradually begin to taper off on Wednesday as the system moves offshore. Gusty winds of 15-25 MPH are possible at times, so in heavier pockets of rain visibility may become an issue. Generally, though, expect this to be a bit of a windy and rainy storm, but nothing too terribly out of the ordinary otherwise — certainly is nothing to board up over.

I’ll post some additional information as it comes through the weather wire during the day in the comments as we begin to get a better handle on what’s going to happen over the next two days. Stay tuned.