Jonathan Conder

High Risk Tonight, Mainly for Damaging Winds

June 12th, 2013 at 2:41 pm by under Weather

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A “High Risk”  has been issued for the WANE viewing area tonight for an expected line of damaging winds and if the line of winds is longer than 240 miles, it will become a derecho.  Again, the main risk is for damaging winds from 70 to 80 mph between 7PM to 11PM, but besides the wind risk there is a chance of tornadoes with any storms that fire out ahead of the squall and there is a risk of isolated tornadoes within the squall line.

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Besides the wind risk up to 80 mph and the tornado risk, hail up to 2″ is possible and heavy rainfall from 2-4″ may pose a flash flood risk late tonight.  That is why the National Weather Service has issued a Flash Flood Watch for the counties highlighted in green below.

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Remember, if you see any flooding over a road, do not drive through it.  Flash flooding is the number one severe weather killer.   Below is the expected rain amounts in the next 24 hours:

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This is based on the current track of the complex of storms, but if this track changes, the higher rain fall bulls eye may move.

Remember, please be severe weather aware this evening and if possible, try not to travel between 7-11PM as this is the highest risk of damaging winds.


Will we have a “Derecho” tonight?

June 12th, 2013 at 10:40 am by under Weather
"Shelf Cloud" produced by a line of damaging winds or a "squall line."

“Shelf Cloud” produced by a line of damaging winds or a “squall line.”

We are expecting severe weather later today, and mainly late tonight, but are we going to see a “derecho?”   A derecho is what we had last June and a derecho (pronounced “deh-REY-cho” ) is a widespread, long-lived wind storm that is associated with a band of rapidly moving showers or thunderstorms.

By definition, if the wind damage swath extends more than 240 miles and includes wind gusts of at least 58 mph (93 km/h) or greater along most of its length, then the event may be classified as a derecho.

So, about how long would the line of storms tonight need to be in order to be classified as a derecho?   Well, it is about 250 miles from Lansing Michigan to Indianapolis and to be classified as derecho, the swath of damaging winds need to be about that wide, or at least 240 miles.

As far as I am concerned:

  • I think it is too early to call it a derecho as the event has not happened yet.
  • At this point, I think it is semantics on what we call it:  Squall Line, Bow Echo, Derecho, Quasi Linear Convective System
  • Hands down, damaging winds are expected tonight, ranging from 70-80 mph.
  • A squall line can produce similar damage to smaller tornadoes.
  • Isolated tornadoes are possible along the line of damaging winds tonight.

Even though we are expecting this line of damaging winds to move in near or after sunset, there is still chance of discrete, rotating storms into the afternoon with a possibility of tornado.

Hands down, now is a good time to secure your lawn ornaments and to download your WANE text alerts.


Moderate Risk Severe Storms Wednesday

June 11th, 2013 at 3:12 pm by under Weather

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Get ready for several rounds of thunderstorms Wednesday and the storms later in the day may pack a punch.  The biggest risk for Wednesday will be for damaging winds with any storms during the evening, but there is also a risk of moderate sized hail, isolated tornadoes and then localized flash flooding.  The official risk from the Storm Prediction Center for our area is in the map below:

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As I mentioned in my weathercast last night and in yesterday’s blog post, I expected our area to be upgraded to a moderate risk.

As of now, look for three rounds of storms:

  • Round 1 near daybreak Wednesday: 3-8AM (Severe storms are possible)
  • Round 2 in the afternoon Wednesday: 3PM to 6PM (Main risk will be micro bursts and isolated tornadoes)
  • Round 3 in the evening Wednesday: 8PM to 2AM  (Main risk will be widespread damaging winds and isolated tornadoes)

In the map below, I have highlighted two main areas of concern:

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In the map above, I expect round 2 to be near the IN/MI state border with storms being discrete.  The area highlighted in red has the highest afternoon tornado risk, since the surface winds will be out of the East, enhancing the low level shear.  The area highlighted in blue is where I expect a line of storms to evolve into a larger complex, producing wide spread damaging winds with isolated tornadoes.  I think it is still a little early to determine if this will evolve into a large derecho like what we say last June, but I do expect some smaller bow echoes.  Hands down, we all need to be severe weather aware Wednesday afternoon and Wednesday night.

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Besides the storm risk, heavy rainfall may make for localized flash flooding.  Above is our total rain forecast to include all the rain between now and Thursday morning.  Yes, we expect widespread 1-2″ with 3″ possible in the area highlighted in purple.

Now, here is my big disclaimer:  If our morning storms don’t move out, or if storms fire by the early afternoon and we don’t hit the upper 80s, our severe weather risk will be suppressed a bit.   But, if you step outside by 4PM and we are sunny with high heat and humidity, get ready for those strong storms.


Severe Storm Risk Wednesday

June 10th, 2013 at 10:03 pm by under Weather

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Even though Monday was quiet and Tuesday is expected to be the same, don’t let that fool you.   We are monitoring the risk of severe storms for Wednesday and as of now, the main risk appears to be damaging winds.

Now, here is the deal:  It is still a little early to call the exact mode of the storms (single cell or multi-cell) or if there will be enough heat and humidity in place when the storms roll through (fuel for stronger cells), but….. everything I have looked at for Wednesday says the environment will be primed for some sort of severe weather in the area.

The map above is an outlook from the Storm Prediction Center, for a slight risk (area highlighted in yellow) of severe storms for our area and honestly, I would not be surprised to see this outlook upgraded to a “moderate” risk.

Again, the main risk is going to be damaging winds, but there will also be a risk of moderate sized hail and an isolated tornado can not be ruled out.

So, if it was going to be a significant wind event, what are we looking for?  Here are some of the ingredients:

  • 3KM Rear inflow jet
  • Moderate to strong low level shear
  • High CAPE
  • Dry mid-levels to enhance evaporative cooling and the cold pool.
  • A stationary front

When I look at the set up for Wednesday, I see many of these ingredients in place.    The biggest wild card will be how much sunshine and heating we see in the afternoon between the morning rain and the storms late.   The longer the break in between storms, the higher the risk and the higher the probability of severe weather.

Besides the risk of storms for Wednesday, we also need to address the “flooding risk.”

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The map above is my total rain forecast for Wednesday and Thursday and somewhere in the 2″ band (area highlighted in light blue) there may be an area of rain over 3″.  At this point, it is a little too early to locate the exact position of the heaviest rain, but I would not be surprised to see localized flash flooding early Thursday morning.   Yes, the one spot in your neighborhood that always floods, may be under a flood risk for Wednesday night into early Thursday morning.

So, what can you do to stay weather aware?

  • Sign up for our WANE text alerts.
  • Monitor our WANE weather blog,Facebook page and Twitter Feed (@wanewx).
  • Make sure your NOAA Weather Radio has new batteries in it.
  • Watch 1st News Wednesday Morning with Greg Shoup to get your updated forecast.
  • Keep on eye on the weather map and crawl on WANE TV Wednesday afternoon and evening.

Never Stop Under a Highway Overpass

June 7th, 2013 at 9:20 pm by under Weather

Never stop under a highway overpass during severe weather!

This video is from tornadovideos.net and shows what will happen to you if you seek shelter under a highway overpass during a tornado.  (scroll ahead to about 2:00 to see why.)

The damaging winds from straight line winds and tornadoes are accelerated as they pass through the confined area under the overpass.

Also, road debris and dirt usually collects there, so during a tornado, they we be sent through the air as projectiles.

Third, this will also cause traffic congestion which may cause an accident or prevent law enforcement and medical crews from passing through.

Again, NEVER SEEK SHELTER UNDER A HIGHWAY OVERPASS!

 


Going to Germanfest?

June 7th, 2013 at 4:59 pm by under Weather

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Are you heading out to Germanfest tonight?  If you are, enjoy near perfect conditions with a partly cloudy sky, no rain, a light breeze with temperatures in the 60s.


Spotter Network Tribute

June 6th, 2013 at 7:50 pm by under Weather

Spotternetwork.org is a website where storm chasers and weather spotters can register, plot their location and give reports.  I am a huge proponent for Spotternetwork as it holds chasers accountable for their reports and it is a centralized location to find accurate storm reports.

This animation above is a tribute to the three veteran storm chasers that died last Friday in the El Reno tornado.   Imagine, each dot is a chase car and that dot, marks their current location.


First Named Storm of the Hurricane Season, here is the Outlook.

June 6th, 2013 at 7:42 pm by under Weather
Tropical Storm Force Wind Speed Probabilities - Courtesy the National Hurricane Center

Tropical Storm Force Wind Speed Probabilities – Courtesy the National Hurricane Center

Now that we have our first named storm of the 2013 Atlantic Hurricane Season, I thought now would be a good time to go over the outlook for this year.

Here is the official forecast or outlook from the Climate Prediction Center:

  • 13-20 Named Storms
  • 7-11 Hurricanes
  • 3-6 Major Hurricanes

Even though NOAA does not make an official forecast for how many US landfall hurricanes are expected, they do expect more than average this season.  The next outlook for the 2013 Atlantic Hurricane season will come out in August.

 


El Reno Tornado and Storm Chasers

June 5th, 2013 at 9:08 pm by under Weather

I came across this YouTube animation earlier today.  This shows all the “registered” storm chasers as they were either trying to intercept, or avoid the El Reno EF-5 tornado last Friday.

I also came across a few other articles about the El Reno tornado.

KFOR Meteoroloigst Taking Heat for Telling People to Flee Friday’s Tornado.

El Reno Tornado, unusual and very deadly by Jon Davies

I was chasing when chasing wasn’t cool by Dan Satterfield

How did storm chaser Tim Samaras, one of the safest, most cautious chasers, get killed in a tornado?


El Reno Tornado Upgraded to EF-5

June 4th, 2013 at 1:24 pm by under Weather
May 31st El Reno storm track courtesy the NWS Norman Oklahoma.

May 31st El Reno storm track courtesy the NWS Norman Oklahoma.

The National Weather Service has just upgraded the May 31 El Reno, tornado to an EF-5 with a maximum width of 2.6 miles wide, making it the widest tornado ever documented.

The upgrade was based on information from a mobile doppler radar measuring winds of 296 miles per hour.  This was not the DOW, or Doppler on Wheels, but the OU RaXPol data.
The EF scale is a damage scale and is only accurate unless the tornado hits something.  Maybe a new scale needs to be added, that incorporates mobile doppler data, called the “DIEF” scale, for the “Doppler Indicated Enhanced Fajita” scale.
The F-4 Wilber-Hallam, Nebraska, tornado May 22, 2004 was the previous record holder for the widest tornado on record at 2.5 miles wide.  Actually, I was out chasing in Nebraska on that same day of the Hallam Tornado, but on the storm just to the north and that day was likely my scariest day storm chasing ever.