The dry weather that has persisted into April has raised concerns. In western Kansas, and indeed the entire state, this has been among the driest starts to the year on record. A map showing the total rainfall for 2018 through April 15th by division and the historical rank since 1895 is shown below (Figure 1).
Figure 1. January-April precipitation ranks for Kansas since 1895 (NCEI data).
In addition to the dry conditions, strong winds have created increasing problems with blowing soil and dust storms. Table 1 compares this year’s average wind speeds at the National Weather Service 1st Order stations to data at the same location from 1930-1996. In addition, you can see how many days in 2018 experienced average wind speeds greater than or equal to 20 miles per hour for each location (>=20 mph).
Table 1. Comparison of average wind speeds from 2018 in Kansas to the historical average (1930-1996)
|
Location |
|
January |
February |
March |
April |
|
Concordia |
Historical Wind Speed* |
12 |
12 |
14 |
14 |
|
|
2018 Average |
10.5 |
11.5 |
12.7 |
13.7 |
|
|
2018 days avg >= 20 mph |
0 |
0 |
3 |
1 |
|
|
Historical Peak Gust |
60 |
52 |
54 |
64 |
|
|
2018 Peak Gust |
50 |
53 |
56 |
57 |
|
Dodge City |
Historical Wind Speed* |
11 |
11 |
12 |
12 |
|
|
2018 Average |
12.4 |
13.6 |
14.3 |
16.2 |
|
|
2018 days avg >= 20 mph |
3 |
1 |
8 |
5 |
|
|
Historical Peak Gust |
66 |
57 |
48 |
61 |
|
|
2018 Peak Gust |
64 |
59 |
66 |
66 |
|
Topeka |
Historical Wind Speed* |
13 |
13 |
14 |
14 |
|
|
2018 Average |
11.7 |
12.2 |
13.6 |
16 |
|
|
2018 days avg >= 20 mph |
2 |
1 |
4 |
4 |
|
|
Historical Peak Gust |
64 |
51 |
53 |
54 |
|
|
2018 Peak Gust |
57 |
52 |
69 |
77 |
|
Wichita |
Historical Wind Speed* |
10 |
10 |
12 |
12 |
|
|
2018 Average |
8.2 |
8.9 |
10.3 |
11.7 |
|
|
2018 days avg >= 20 mph |
0 |
0 |
0 |
0 |
|
|
Historical Peak Gust |
49 |
47 |
43 |
47 |
|
|
2018 Peak Gust |
47 |
43 |
47 |
53 |
|
All speeds are in miles per hour (mph); Historical data is in bold |
|||||
|
*From “Climatic Wind Data for the United States; NCDC Nov. 1998; based on 1930-1996 data. |
|||||
Note that in April, Topeka, and Concordia had winds that matched the historical average. In Dodge City, the wind speed in April was more than 4 mph above (or 15% greater) than the historical average; and in Goodland wind speeds were 2 mph above average for April. The Kansas Mesonet also shows very high average wind speeds for April 1 – April 15th (Figure 2). In 2018 there has also been many days with severe wind (>=20 mph). There are not good historical records for the number of days with wind speed >=20 mph, but it is likely 2018 has seen more days than normal since average wind speed is considerably greater. Besides having a greater average wind speed and number of severe windy days, the peak wind gusts have also been greater. The peak gust in April was 5 mph higher in Dodge City, 23 mph higher in Goodland, and 6 mph higher in Topeka. With these severe winds there has likely been more property damage than normal and caused quite a bit of soil blowing and wind erosion.
Figure 2. Average wind speeds at 2 meters from April 1-17, 2018. (Kansas Mesonet)
What conditions create high winds?
The jet stream plays the main role in creating wind events. The pattern for much of the year has been northwest flow aloft across the Central Plains (Figure 3). This pattern is associated with cooler conditions, dry air, and frequent dry cold fronts across Kansas. A day in advance of a cold front, winds shift southerly and increase (and temperatures warm) due to a strong pressure gradient. Winds shift northwesterly with the passage and typically remain gusty for 1-2 days after the front. Dry conditions actually help to fuel stronger winds, so it is not surprising we have experienced increased winds with the extremely dry spring. With persisting dry air masses across the state, when the sun comes out, air is able to rise more effectively. This in turn pushes stronger winds aloft downward to replace it. Therefore, repeatedly mixing them down provides windier-than-normal conditions especially combined with the increased frequency of cold fronts (which is typical for March and April).
Figure 3. 48-day average 500mb winds (NCEP).
As a result of the drought and windy weather, dust storms have been common this year (Figure 4).
Figure 4. Dust storm in Ford County, April 16, 2018. Photo by John Holman, K-State Research and Extension.
For information on protecting your soil during high winds, check out the recent eUpdate article: “Emergency measures to control wind erosion” in the April 18, 2018 issue and the KSRE publication MF2206, “Emergency Wind Erosion Control”
You can find up-to-date information on the drought status in Kansas on the Kansas Climate page at http://climate.k-state.edu/reports/weekly/2018/
John Holman, Cropping Systems Agronomist, Southwest Research-Extension Center
jholman@ksu.edu
Chip Redmond, Kansas Mesonet Manager
christopherredmond@ksu.edu
Mary Knapp, Weather Data Library
mknapp@ksu.edu
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