Cambria Tornado & Less Humid Days Ahead

***Watch WISN 12 News for the latest weather information!***

Thank you for stopping by the Weather Watch 12 blog.  After Wednesday’s heavy downpours in Milwaukee, and the brief tornado near Cambria, the quiet weather on Thursday was welcomed. 

The Cambria tornado was produced by an isolated low-topped supercell.  It spun up quickly and without warning.  Here is video of the tornado just south of Cambria!

Here is the very latest on the tornado from the NWS survey that was conducted on Thursday.

The tornado was rated EF-1, with winds estimated at 90-95 mph.

Below is a map for the tornado’s path.  The path length was 4 miles, and the tornado was on the ground from 6:27-6:41 p.m.  Below is a map of the path, and also a couple of damage highlights.  Just click on any of the images to enlarge.

During our tornado coverage last evening from 6:30-7:30p on WISN 12 we showed the velocity of the storm numerous times.  This helps us guage the direction of the winds within the storm.  When a tornado occurs a tight ‘couplet’ will often appear on the radar.  When green(toward the radar location) and red(away from the radar location) are right next to each other in velocity mode, this indicates rotation.  Often when this rotation appears a tornado is either on the ground or possibly about to develop.

Below is the velocity at 6:32 p.m. when the tornado was on the ground.  This map is from the NWS NEXRAD radar.

If you have ever heard us say “Radar indicated tornado”, that means something like the map above is showing rotation, but no spotters have reported a tornado.

The good news is we shouldn’t have to worry about thunderstorms or severe weather for a few days.  Cooler and less humid weather will return to the region on Friday.  below is a surface map from 4 p.m. Thursday.  When looking at this map check out the dew points in the 50s in central Wisconsin.  The dew point(green number) in Wausau was 55 degrees, while in Milwaukee it was still a sticky 68!  The lower dew points will try to work into our area in the next 24 hours.

Enjoy the quiet and less humid weather, and make sure to stop back for an all new weather blog again on Friday!

Have a great day!

Jeremy Nelson

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6 Responses

  1. I am hoping the WISN meteorologists can clarify something for me. I have had questions regarding the use of tornado sirens but no one has been able to answer them satisfactorily.
    My understanding is that tornado sirens go off when a tornado has been confirmed and is threatening the community where the siren is located.
    I live in the northeastern corner of Dodge County between Lomira and Brownsville, about a mile in both directions. Last night the tornado sirens went off in both villages when the warning for Dodge County was issued. However, that storm was on the other side of the county headed NE, coming nowhere near our area, yet the sirens went off.
    My understanding is that when we hear sirens we head for shelter. There was no need to do that last night where I live. In fact, the sun was shining here the entire time.
    WISN interviewed Sheriff Nehls last night and he said that we take tornado sirens very seriously up here. I beg to differ with him. People are becoming desensitized to those sirens. I honestly think they are being over-used causing people to not take them seriously. They go off so many times here when nothing really is happening.
    I know they are meant for our safety, but shouldn’t they only be used when there is actually a tornado that has been sighted and it is approaching? The track of last night’s storm was away from us. Those sirens should not have been going off, or was it because it was a county-wide alert? Still, a county-wide alert was not necessary either because the location of that storm was in the far NW corner of the county.
    Sorry for the ramble, but it is frustrating to hear those sirens warning us to take shelter when the reality is different.

    • Cliff,

      Thanks for the comments. Warnings by the NWS are now issued in polygons, which helps in isolating parts of a county that are under the warning. Last nights warning was for just northwestern Dodge county. Now when it comes to sirens going off or not I believe that is up to each cities/towns emergency management officials. It would be nice if there was an across the board standard for use of sirens, but that is not the case. Couple of examples good and maybe not so good. I’m not a fan of towns sounding a siren at ‘x’ time each day. I know a town in Waukesha county that sounds the sirens at noon each day. A good example of sounding sirens when a tornado warning is NOT issued is in the case of damaging straight line winds. Some towns will sound the sirens if say winds of 70+mph are moving toward an area and there is just a Severe T-Storm Warning in place. The issues of sirens can be confusing, but a good rule of thumb is if where is near and you hear the siren, just head to the basement, turn on your tv or bring a weather radio with. Those are my thoughts. Jeremy

    • Cliff – your frustration is not even a local area, rather a point of discussion all over the nation. Jeremy is right that it is typically that of country or city officials as to when/why to sound sirens. There is not typically very good coordination nor consistency between different areas regarding criteria for the alarms.

      As the NWS has advanced to polygon warnings, weather radios have not. If a municipality has a policy to sound sirens based on EAS alerts [county based], then the sirens will go irrespective of the polygon track.

      As a general rule of thumb, if you hear sirens [except for obvious testing], one should take cover and listen for updates. I agree it can be very frustrating – especially for very localized storm activity.

    • Didn’t see that…thanks for passing along! Jeremy

  2. Thanks for the reply about tornado sirens. It would be great if there were some across the board rules regarding their use. By the way, you mentioned about a community in Waukesha County sounding sirens at noon. Both Lomira and Brownsville sound their sirens every day at noon too.

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