Tuesday Afternoon Update- Tropical Storm Arthur

Well since my last blog post the disturbance off the southeast coast has strengthened and is now classified as Tropical Storm Arthur! This is our first named storm of the 2014 Atlantic Hurricane Season. Arthur still seems to be on track to impact Eastern VA and especially Eastern NC as we approach July 4th with some rain, wind and coastal flooding.

To strengthen, hurricanes need several things. First, they need little wind shear to allow t-storms to form over the center. They also need warm sea surface temperatures and moist air. To get a very strong storm, typically you’d want to see some good symmetry on the system too with storms around each side of the center or eye of the storm.

symmetryAt 2 pm Tuesday, the storm was off the coast of FL and becoming better organized. In the past few hours, we’ve noted a flare up of t-storms on the northern side of the system, which is what you want to see if you want the storm to strengthen. In the image to the right, I’ve outlined each quadrant and talked a little about the storm activity in it. For the past day, most of the storms associated with Arthur have been on the southern side so this flare up on the northern side is noteworthy.

Water Vapor TueIn terms of moisture, there is some dry air on the northern side of the system in the mid levels which I believe isn’t really allowing storms to fire up significantly on the northern side of the system. As we go through tonight and tomorrow though, we expect the storm to overcome this dry air and get better organized. So, with 2 out of 3 of the ingredients seeming to becomd more favorable, what about sea surface temperatures?

usatlant.cfWell… sea surface temperatures also seem to support a tropical system. Usually you want temperatures in the upper 70s to 80s to support tropical storm or hurricane strength storms. With the warm Gulf Stream waters near the storm, these temperatures won’t be an issue and we expect the storm to strengthen as atmospheric conditions become more favorable with the combination of these 3 features improving.

The National Hurricane Center’s current track expects Arthur to approach the Outer Banks as we go into Thursday night and Friday morning as a Category 1 hurricane. Note though that Hampton Roads and Eastern Carolina are still in the cone of uncertainty. A 25 mile jog to the west could significantly change the impacts to the Outer Banks and VA.

So what is the bottom line? Basically, we just need to watch it. Right now, the storm system does not seem overly significant for Hampton Roads and if storms do not fire on the western side and we don’t get good symmetry of the storm, rain and wind will be pretty tame across Eastern VA. Hatteras,NC seems to be in the path to take the brunt of the storm. If you’re traveling down there, be aware of conditions and know that water often covers NC-12 in spots during storms. Be prepared to even be stuck there if the road gets washed away or sand covered. NCDOT will do their best, but you can’t always beat Mother Nature.

Main Headlines:

- Rain and some wind possible Thursday night into Friday morning across Hampton Roads
- Biggest impacts with Tropical Storm strength winds across NC Outer Banks
- Dangerous surf conditions with rip currents and large waves
- Conditions improving Friday night across all areas
- Weekend perfect across the area! Don’t cancel plans.

What you should do:
- Stay Tuned…
- If traveling SE to the Outer Banks Thursday night or Friday, consider postponing until Friday afternoon

Tropical Trouble on the 4th of July?

A tropical disturbance off the coast of FL could cause trouble to vacationers heading to the Outer Banks or southeast coastline as we approach the 4th of July holiday. The main impacts to Hampton Roads, depending on the track would be some heavy rainfall Thu night into Friday, minor coastal flooding, rip currents, increased waves and some gusty winds.

TropicalAs of 5pm Monday, an area of storms located off the eastern coast of FL was starting to get better organized and could become our first tropical system of the year. If this happens, it would be named Tropical Depression 01 and then Arthur once it has sustained winds of 39mph. USAF Reserve Hurricane Hunter Recon aircraft found 30-35 mph winds Monday afternoon, but insufficient t-storms around the center caused the National Hurricane Center to not name the system yet. It wouldn’t shock me to see this area classified as a tropical depression Monday night or Tuesday.

Those of you who have lived on the coast for any amount of time know that the track of a system is key to the impacts. At this time, most of the model guidance is showing the system moving NW then turning NE and skirting the NC coastline as a front approaches from the west and helps to curve the storm away from the coast.ecmwf_slp_precip_nc_15 In the picture to the left, you can see the front and the storm approaching on the European Weather Model. The key to our impacts, is when does the front arrive and how strong is the storm when it does? Typically, a stronger storm would be impacted more by the front. A weaker storm though, could bring more rain to us as the front interacts with the system and causes the rain to spread north.

Intensity forecasting is tricky, and with a storm close to the coast there isn’t much room for error. Personally, this does not look like a huge system but keep in mind, even a strong tropical storm or a weak hurricane can cause many issues, especially on the vulnerable Outer Banks. We’ll have lots of people in Eastern NC and SE VA this weekend who may have never experienced a hurricane or even know what one is. If you’re reading this and that applies to you, don’t cancel your plans though! The weekend Saturday and Sunday looks excellent once the storm passes.

So Here is the Bottom Line:
- Area of storms off the coast of FL could become our first tropical storm this season
- Most likely track for now shows the storm brushing the Outer Banks of NC
- Rain, gusty wind, high waves, dangerous ocean conditions and coastal flooding main impacts across NC,SC and VA.
- Those traveling to the OBX for 4th of July Weekend should NOT cancel plans, but be aware. After Friday, Sat and Sun look excellent!

What You Should Do:
- Keep aware of future forecasts
- Be prepared for some heavy rain, tropical storm force winds (39+ mph) and some coastal flooding late Thu into Friday.
- Know that 4th of July Fireworks may be canceled in many areas depending on the track.

4/25/14 Storm Chase Recap

Starting Thursday, myself and a few other UNCC meteorology majors were beginning to get worried about the potential of severe weather and tornadoes across NC Friday afternoon. Come Friday morning, it was evident that the threat was more likely, and Thomas Winesett (UNCC Graduate Student) and I decided to chase the storms.

There are many reasons why meteorologists and weather enthusiasts chase storms. Some do it for the thrill of being close. Some do it to try and get video to sell. Others, like me, do it to try and help the NWS and local media. Having interned with several TV stations, I’ve made connections with several TV meteorologists in the NC region. My goal on Saturday was that if we saw any tornadoes or severe weather, to get a picture of the tornado to the local TV stations and the report to the NWs, so that they could warn people on air about it. Social science has shown over the past few years that people want multiple and visual confirmation of a threat before taking action. Therefore, it was our hope that if the public saw the pic, they would take action.hires_ref_nc_8

Screen Shot 2014-04-26 at 12.32.05 PM

SPC outlook with reports. Red dots are tornadoes. Photo via @USWeatherExpert ‘s blog

We started the chase by leaving from Charlotte around 11am after seeing that the NAM-4km model, one of the many weather models we use to make forecasts had a few discrete, strong supercells across eastern NC around 3pm.  Heading east, we got the 12:30pm update from the NWS’s Storm Prediction Center and noted that they had upgraded a large portion of central/eastern NC to a hatched 10% tornado risk. Here in NC, a 10% tornado risk zone is pretty rare, and hatched risks are even rarer. A hatched risk is issued when there is a  10% or greater probability of EF2
- EF5 tornadoes within 25 miles of a point. Shortly after, storms started to develop just north of Fayetteville,NC around Dunn, and we decided that those would be the storms we went after. 

As we got close to the storm near Dunn, the NWS issued a Severe T-storm Warning for the cell due to the threat of large hail. We noted what is called a Three Body Scatter Spike, which is where the radar hits hail coated with water in the storm and reflects it back as a false return on radar below the storm. This is great info for us to see, because it tell us we don’t want to drive our car into the storm! DSC_0456

The terrain of eastern NC is unique. In some spots, you have dense forest while in other areas, there is wide open farmland and clearings. This open terrain is great for us, because it allows us to stay a safe distance away from the storm while still viewing what is going on. When we first got a clear view of the storm, we DSC_0473noticed it had a wall cloud – a precursor to a tornado that indicates rotation in the cloud. The storms were in an environment that was very supportive of rotating updrafts, the kind of updrafts that storms need to produce tornadoes. We followed this storm north and east, eventually reaching the town of Goldsboro. By this time, the NWS had issued a Tornado Warning for the storm, saying that doppler radar indicated the potential for the storm to produce a tornado.

2014-04-26_23-54-55

Short tornado to the right of me

Following the storm as it passed through Goldsboro, we took a few back roads trying to get out of the city and get another visual on the wall cloud. It was at this time, the storm really began to intensify. We parked at a church to watch, and a few moments later the storm produced a small tornado. The interesting thing about this tornado was that the main condensation funnel never touched the ground. If you look at the picture to the right, you’ll see the tornado in the haze to the right of me. The tornado was only visible due to dust and other debris being kicked up by the storm.

This tornado wouldn’t be the only one we saw that day though! We continued tracking the storms towards Snow Hill and Farmville, where the storm dropped another short lived tornado! Both times, I was able to get a picture out via social media where @nsj, @LeeRingerWX, @wxbrad and others were able to share it and at times us on air.

20140425_190017DSC_0531Around 5:30pm, the storms started to cluster together and become less organized. Due to this, and closed roads, we decided to bail on this storm and head back further south. Another storm had formed and we decided to towards it. After arriving, we noted a very strongly rotating wall cloud and shortly after, a funnel cloud formed. At this time, the rotation wasn’t strong enough for it to touch down but later it did produce an EF-3 tornado in Beaufort County. We never were able to catch up to the storm due to bad roads and nighttime, but did manage to find some over golfball sized hail!

 

Other pictures from our chase below:

NC reports

Storm Reports

hodo

BUFKIT Hodograph and Sounding for KRDU

Chase 2 cars on road

Traffic on the highway as others saw the wall cloud and were hit by small hali

Chase 3 Elongated Wall Cloud

Wall Cloud

Chase 1

Storms!

 

Winter Storm to Impact Hampton Roads on Monday

Monday will not be a fun day across Virginia. Travel will be difficult, if not dangerous at times. Businesses and schools are advised to plan ahead. This storm will be one where people will wake up at 7-8am and think, “Where is the storm?” Around 9 am, the sleet/snow will begin and everyone will freak out and leave, creating lots of traffic…

Another winter storm is going to impact the state on Monday, blanketing the state in snow and sleet. Winter Storm Watches and Warnings are out for many areas. WatchThe storm will begin as sleet in many areas, before transitioning to snow as the colder air works in. Total snowfall accumulations will vary from west to east, with the highest amounts typically being across north and western VA including the campuses of JMU, UVA, UMW and Washington DC. South and east of there, snow will mix more with sleet, and this will cut numbers down.

Rain vs Sleet vs Freezing Rain

Why does sleet form instead of snow? It’s due to warmer air aloft. When air above the ground is above 32°F, the snow that falls from the clouds melts on the way down. However, since the warm air is very shallow, and the air near the surface is cold, the water drops refreeze on the way down. They become ice pellets.

(Note: Sleet and hail are NOT the same things. Hail is a convective precip type that occurs when water drops are lifted up into a thunderstorm and then fall over and over in updrafts). 

How can you tell sleet from snow or rain? It’s simple! Sleet bounces and pings off your window. Rain and snow does not! If you see sleet, please let us know by reporting it on the mPing app. This app allows meteorologists to get ground proof of what precip type is falling, since radar actually scans a few thousand feet up into the air. The app is available for Android and Apple products.

Let’s break down the storm in terms of impacts:

Radar

TIMING: 

  • Hampton Roads- Sleet begins around 9am and lasts through about noon. Snow begins after.
  • Richmond- Sleet begins around 7am, transitions to snow around 10am.
  • William and Mary/Williamsburg-Sleet begins around 9am, now around 11.
  • JMU/Harrisburg- Storm begins around 2-4am.
  • UVA/Charlottesville- Storm begins around 2-4am.
  • VT/Blacksburg/Radford- Begins during late morning
  • Longwood/Farmville- Sleet begins around 8am, transitions to snow around 11am.
  • UMW/Fredericksburg- Sleet begins around 2-4am, transitions to snow around 8am.

Amounts:

  • Hampton Roads- 1-4″. Depends on how much sleet mixes in. If less, totals more
    towards higher range.
  • Richmond- 3-6″ with some sleet accumulations
  • William and Mary/Williamsburg- 3 to 6″ with some sleet accumulations
  • JMU/Harrisonburg- 6 to 12″
  • UVA/Charlottesville- 6 to 12″
  • VT/Blacksburg/Radford- 1 to 3″
  • Longwood/Farmville- 4 to 6″
  • UMW/Fredericksburg- 5 to 10″

The numbers above is my current thinking. The map below, is from the National Weather Service.

totalsnowNational Weather Service Forecast