Latest NWS statement on freezing drizzle potential overnight

My emphasis added…

…PATCHY FREEZING DRIZZLE OVERNIGHT INTO EARLY TUESDAY…

TEMPERATURES AROUND FREEZING WILL SETTLE INTO AREAS NORTH OF
INTERSTATE 16 AND AWAY FROM THE IMMEDIATE SOUTH CAROLINA COAST
OVERNIGHT INTO EARLY TUESDAY. AS A RESULT…DRIZZLE COULD BEGIN TO
FREEZE ON SOME ELEVATED SURFACES.

DUE TO THE COMBINATION OF EVAPORATION ENHANCED BY PERSISTENT
WINDS…THE EXPECTED LIGHT AND SPOTTY NATURE OF ANY DRIZZLE AND
THE LINGERING EFFECTS OF TEMPERATURES IN THE 70S SUNDAY AND
MONDAY…DRIZZLE IS NOT EXPECTED TO FREEZE ON ROADS AND SHOULD
NOT IMPACT TRAVEL. VERY LIGHT ICE ACCUMULATION…IF ANY…WOULD
BE LIMITED TO TREE BRANCHES AND OTHER SURFACES ABOVE THE GROUND.

IF MORE SUSTAINED FREEZING DRIZZLE OR LIGHT FREEZING RAIN
DEVELOPS…THERE IS A VERY LOW PROBABILITY FOR SLICK SPOTS
ON SOME BRIDGES AND OVERPASSES LATE TONIGHT INTO EARLY TUESDAY.
HOWEVER…EVEN IN A WORST CASE SCENARIO THE IMPACT OF ANY ICE
ACCUMULATION OVERNIGHT WOULD NOT COMPARE WITH THE IMPACT OF
THE ICE STORMS THAT OCCURRED IN JANUARY AND FEBRUARY
.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

KEEP UP TO DATE WITH THE LATEST FORECASTS AND INFORMATION FROM
THE NATIONAL WEATHER SERVICE IN CHARLESTON.

Will be a conversational glaze at worst, it looks like. School will be open, the Ravenel will be open…Charleston will be open for business tomorrow. Proceed normally.

After today, below normal temperatures for the rest of the week

NWS forecasting a high of 77 today before major post-frontal changes tonight — Freeze Watches are up for the coastal counties, while Freeze Warnings are up for the inland counties. (The NWS has resumed its frost/freeze program with the growing season back underway.)

Something to watch: Small potential for freezing drizzle/light freezing rain tonight particularly inland. Don’t be shocked to see a Freezing Rain Advisory come out if these chances improve, but also don’t expect to see many issues from this given our expected high 70s today and the relatively short duration of any freezing precipitation — as it stands right now, this won’t be a “shut it all down” event.

Tomorrow’s NWS-forecasted high of 43 is 34 degrees cooler than what’s expected today. Temperatures moderate somewhat starting Tuesday but highs in the mid-50s are this week; at times highs will run as many as 10-15 degrees below normal for early March (upper 60s are the typical highs).

Great weekend ahead

All yesterday’s cold front did was knock us from the 80s to the upper 60s — and as far as cold fronts go this winter, that’s A-OK. Great weekend ahead with passing clouds (but plenty of sunshine) and temperatures still slightly above normal in the afternoons.

Unfortunately, winter continues to rage on and we could see our next Arctic blast by mid-week. More details on that later today or tomorrow. In the meantime…get out and enjoy!

Severe Thunderstorm Watch until 2PM

6:50 AM radar composite and Severe Thunderstorm Watch outline. Subject to change. Image: GREarth

6:50 AM radar composite and Severe Thunderstorm Watch outline. Subject to change. Image: GREarth

The National Weather Service has issued a Severe Thunderstorm Watch including the Charleston Tri-County area until 2PM ahead of a potent cold front and its associated squall line. The primary concern is for damaging straight-line winds. While far less likely, an isolated tornado along the leading edge of the line cannot be totally ruled out.

Expect the squall line to begin to affect the western parts of the area late this morning (around 11am); it will make its push to the coast by 1pm. The line will be clear of the area by the evening rush and should not affect the commute.

Inland locations affected by the recent ice storm will be particularly susceptible to additional damage to weakened trees. It won’t even necessarily take a gust that meets severe criteria (58 MPH) to cause problems. Stay indoors as storms approach.

Make sure you are able to reliably receive warnings today and take action if needed.

Friday thunderstorms

At 1:30am, a squall line stretching from New Orleans to Cleveland, OH associated with the trailing cold front from a particularly strong storm system moving into the Great Lakes was steadily moving east at around 30 MPH. The line was roughly 350 miles to the west of Charleston. Tornado and severe thunderstorm watches stretch from Louisiana to Lake Erie and as far east as bordering the upstate of South Carolina.

This line will make steady progress overnight, taking aim on the Charleston Tri-County area during the late morning hours and getting through the metro area in the 1-3 PM timeframe. The line is expected to be steadily weakening as it approaches the coast, becoming further removed from the best upper-air dynamics (and then eventually running into the stable marine layer that often weakens approaching storms). That being said, we’ll have a little destabilization time and some strong to severe wind gusts can’t be ruled out as the line moves through. Also note: A severe weather watch is not out of the question.

People who were hit hardest by the ice storm need to watch this one! Further damage to trees weakened by the ice storm may occur even in thunderstorms that don’t reach severe wind criteria (58 MPH winds) which would normally trigger a warning from NWS.

The line and its associated cold front will get through before the evening rush. High pressure will build in behind it, setting us up for a bit more seasonable of a Saturday (though upper 60s still aren’t too shabby for this time of year!)

Last of the 80s tomorrow

After tying the record high of 83 (first set in 1956) today, we could get close to tomorrow’s record of 82 inland. Closer to the coast, we’ll stay firmly in the 70s. (Beaches may yet be cooler thanks to very chilly water temperatures.) A slightly more southerly wind will draw in some cooler air from the ocean and perhaps keep temperatures down a notch over today — time will tell. Sensible weather will remain generally tranquil with perhaps some passing clouds; coastal areas could contend with some sea fog coming ashore at times.

Friday looks to be a different story; a cold front with showers and potentially some gusty thunderstorms associated with it looks timed to get through during the early-to-mid-afternoon hours. That will keep max temperatures down into the mid-70s before the front gets through. A few storms could produce some strong winds but widespread severe weather is not looking likely. Will update if that changes.

Spring preview continues

We’ll be sticking with mostly dry weather (small chance of showers after midnight for inland locations) and the 70s (locally cooler at the coast thanks to the seabreeze and possible sea fog development) for the next few days. Our next strong front comes along on Friday; this front will likely be accompanied by showers and thunderstorms out ahead of it. Interestingly, the Storm Prediction Center has a large 30% severe risk cut out from roughly the GA/SC border up north through the Mid-Atlantic states — something to watch as the forecast is fine-tuned.

Brewvival folks, take note: Guidance generally agrees the front clears the area late Friday/early Saturday, but the degree to which the front makes it offshore is still in some question. Thus, some lingering showers appear possible Saturday morning, so I’ll need to keep some rain chances around in the early going. At any rate, as things stand right now the major mud event from last year does not look to be in the cards this time, but we’ll need to watch the timing of things carefully. More updates as time goes on.

Unfortunately, the longer-range modeling tends to agree that this spring preview will be ending around the start of March as the pattern shifts back to what we’ve seen for much of January and February: A strong ridge around Alaska, bringing dry and warm weather to the West, and a trough in the East, transporting blasts of Arctic air and routing storm systems through. (April can’t come soon enough.)

For now, though, enjoy the warmth — it is such a nice change from what we’ve dealt with over the last couple months!

Saturday #chswx: Windy but clearing

Surface temperatures, radar, and winds around ~1600ft off the surface. As temperatures rise, these winds will be able to mix down and cause some strong wind gusts.

Surface temperatures, radar, and winds around ~1600ft off the surface valid 10:30am February 15. As temperatures rise, these winds will be able to mix down and cause some strong wind gusts.

The rain and the cold front are gone! In the front’s wake, we have a Wind Advisory through 5PM; gusts to 40 MPH will be possible. This could mean additional limbs or perhaps even a tree or two down in the areas most affected by the past week’s ice storm as well as tricky driving conditions on the bridge (don’t worry, it won’t be closed).

Despite the wind behind the cold front, we’ll still get to near 60 today with decreasing clouds to kick off what should be a nice weekend.

12:36 super-resolution radar image from the NWS radar site in Early Branch, SC. Showers on the way! Image: GR2Analyst

12:36 super-resolution radar image from the NWS radar site in Early Branch, SC. Showers on the way! Image: GR2Analyst

Expect the onset of rain in the Charleston area around 2am or so based on current radar trends. About a quarter of an inch of rain is expected through Saturday morning. Rain will be gone by 10am with clearing to follow — we’ll salvage a decent afternoon with temperatures in the low 60s and plenty of sun. Wind advisories are up for the Tri-County area along with the risk of gales in the coastal waters — gusts upward of 35-40 MPH may complicate ice storm recovery efforts in Berkeley & Dorchester counties.

4.1 earthquake near Edgefield, SC this evening

Many felt a shallow 4.1 magnitude earthquake about 7 miles from Edgefield, SC around 10:23 PM. Reports of the quake have been felt as far south as Claxton, GA and Hilton Head Island according to the National Weather Service and USGS:

Reports of shaking associated with the 4.1 earthquake near Edgefield as received by USGS as of midnight Feb 15.

Reports of shaking associated with the 4.1 earthquake near Edgefield as received by USGS as of midnight Feb 15. Click the image for the latest reports.

While I did not personally feel the quake, many of you stepped up immediately to make a report. The first report I got was from St. George:

Then the reports rolled in from all over:

Fortunately, there are no reports of major damage, though a few pictures have circulated of cracks in floors and drywall in the Upstate. Rumors that the quake damaged a water tower in Augusta, GA are inaccurate as the water tower was conducting a scheduled release from its overflow valve:

We are no strangers to earthquakes here in Charleston with the Summerville fault kicking off occasional tremors (this is the 13th earthquake in the past year for SC). However, quakes centered in the central Savannah River area (CSRA for short) are exceedingly rare:

To learn more about the Charleston area’s earthquake history, I highly recommend scearthquakes.com, which has a lot of information about the catastrophic 1886 quake and the seismic zone near Summerville. The USGS has also compiled many useful links about SC earthquakes as well.

If you felt tonight’s quake, please take a moment and report it to USGS — this helps their data collection immensely, especially in an area that doesn’t feel a lot of quakes.