Kestrel Pocket Weather Tracker

[smorris]

I searched through past posts, but never really found much on the Kestrel handheld weather stations. I thought I'd post here with my thoughts and others with experience could add to the list for future reference.

I used a couple Amazon gift cards left from Christmas to add to my weather conditions monitoring arsenal. I bought a Nielsen-Kellerman Kestrel Pocket Weather Tracker.

There are several Kestrel models, from simple wind meters up to Bluetooth night vision models with built-in ballistics calculators used by the military and competition shooters. There are models specific for HVAC, concrete work, agricultural spraying, racing, and more, from $99 to $849.

http://www.nkhome.com/kestrel

I bought the Kestrel Model 4500. I had narrowed it down to the 4000 or 4500 due to several considerations and needs (well, wants...) I ended up with the 4500 just due to supply and cost on Amazon. It is there top end model, but without the Bluetooth, NV, ballistics, etc, which add several hundred dollars to the cost. So I look at it like the best of the regular models. The only difference between the 4500 and the 4000 is that the 4500 adds a compass, so it can calculate wind direction, crosswind, tailwind. Not a necessity, but for the difference in cost and availability I went that route. I'd have been just as happy with the 4000.



One nice thing about it being waterproof, is that you can dunk it in a pool, stream, glass of wine or whatever and read the temperature.

My interests in getting a portable weather station were varied. One was as verification for the readings on my Davis ISS. A couple of times, I really wasn't sure I believed the temp I was seeing compared to the local NWS office only about a dozen miles away. With the Kestrel, I hang it around the rain collector, out of the sun, right at the level of the FARS fan. Each time I've done this, the VP2 and Kestrel agreed within .1-.3˚

Secondly, I'm doubting my windspeed readings from the VP2. We've had a couple of severe storms come through here, and while the house shook in the wind, the VP2 was only showing 30-40 mph while other sites were getting 50+ MPH. Since getting the Kestrel, we've had one windy evening, and again the wind was from the WSW, which is the direction of the highest trees near my house. While the VP2 anemometer is at about 35 feet, I stood out in the field west of the trees, and was getting about the same reading at 7 feet AGL as the VP2 was at 35 feet AGL. This has convinced me to add 10 feet to my anemometer mast in the spring.

Now that I have the station at home, I find I'm more curious about what's happening around me elsewhere. With the Kestrel, I can take local measurements visiting the family's cabin at the lake, see how humid my Mom's basement is, see how hot it is in my Mother-in-law's un-air conditioned house in July, etc.

It has an available accessory mount that fits on a tripod and adds a wind vane. The Kestrel has data logging, and the increments are user settable. You can log every few seconds for a few hours, or every hour for a couple of months. The 4000 and 4500 both have the capability to temporarily turn themselves on, store a reading, then shut off. You can view this stored data on screen as data or as a chart. Or you can transfer the stored data to a computer and use just like logged data from the Vue.




The data download is reputed to be pretty slow. To maintain waterproofness, there are no ports. Instead, there are optical connections on the back that mate with the proprietary serial adaptor. This is slower than a USB or other connector. I don't plan to download data on mine.

Hopefully that somewhat explains my reasoning in getting the Kestrel. It seems like a fun addition to the tools I have here at home, as well as verification to the readings of the VP2.

Here's a nice video on the 4000 http://www.youtube.com/watch?v=-s2FX1SdnAc The only thing the 4500 has different is a compass, which then allows the calculation and display of headwind, tailwind, and crosswind.

And here's a nice video to show the wind vane accessory. Neat idea to use a Joby with it! http://www.youtube.com/watch?v=5JlCpDC2wJs

There are already a couple of weather apps for Android that work with the Bluetooth Kestrel models.
http://www.nkhome.com/kestrel/software-partners/

From what I've read, Apple's implementation of Bluetooth in the iDevices preclude them from any use other than audio, so no luck there.

I'll continue using and testing it, and report back here with my impressions.
Steve

[smorris]

We just got back from a short vacation in the Great Smokey Mountain National Park. While there, we took the hike up Clingman's Dome to 6643 feet. (It was a lot harder this time, compared to 22 years ago!)

It was in the low 70s in Gatlinburg, but on top of the observation tower it was 55˚. I had my Kestrel with me, and my handheld reading showed winds of 14-17 MPH with a gust to 20 MPH. Lowest windchill I saw was 48˚.

[d_l]

I've long advocated using a Kestrel as a calibration check device for those that are fanatic about accuracy of their Davis equipment.  I have a 3500.  It was the most Kestrel I could afford at the time.

One drawback when using a 3500 for calibration is that unless you have a console with you when calibrating, you must take the temp/hum reading at the end of a logging interval and record it for comparison to the computer records.  This presumes that you are using WL and have it set to record temp/hum at the end of each interval and not averaged over the archive interval.

A Kestrel can also be used to check the air flow rate of your FARS to see if it is up to specs or if grit in the bearings has slowed the fan down which might signal a pending failure.

I wouldn't be concerned about a wind reading at human height matching those at ~10m on occasion.  That would be an indication of a particularly turbulent wind storm vs more laminar storm wind that conform more to logarithmic wind shear laws: http://www.motiva.fi/myllarin_tuulivoima/windpower%20web/en/tour/wres/shear.htm  If you are interested better in characterizing the winds, you might install a second anemometer at a lower height than the one you have.  I frequently see the two different types of wind storms, but I thought that it was mostly due to terrain effects.  In the winter, thermal inversion stratification seems to play a role in keeping the winds more laminar.