Monday, April 9, 2018

Longer Allergy Seasons

The National Phenology Network is showing the early arrival of leaves on trees in the Ohio Valley, the Midwest, and Western United States this year. This trend has become more of a norm over the past past 50 years.  
Climate Central published data this week showing the same trend since 1970 with notable attention to the West where states are seeing as many as 17 more frost-free days, extending the growing season. Here in the Local 6 area, the growth is not as notable but still averaging between 4-9 days additional to the growing season. Why does this matter? Aside from having an influence on which plants are suitable for planting zones, it has a much higher societal impact by extending the allergy season. 

"As the climate warms from the increase of greenhouse gases into the atmosphere, the last spring freeze is trending earlier and the first fall freeze is coming later. This means the growing season is getting longer, and so is the pollen season— whether it is from tree pollens in the spring, grass pollens in the summer, or ragweed in the fall. A study sampling 10 locations from Texas to Saskatoon, Canada indicated that pollen seasons lengthened between two to four weeks from 1995 to 2009, with the largest increases in the northernmost areas.
In addition, increasing atmospheric carbon dioxide enhances photosynthesis in plants, meaning that they produce more pollen. Lab studies have confirmed this, with timothy grass producing twice as much pollen for a doubling of carbon dioxide, and ragweed producing twice as much pollen even before a doubling of carbon dioxide is reached. And the lab studies are supported from the field. One study in Baltimore, where carbon dioxide concentrations were 30 percent higher than outside the city, found that ragweed grew faster and produced more pollen in the city.
Pollen allergies are not just a nuisance. Asthma symptoms can be triggered by exposure to pollen, with the number of emergency room visits increasing on days with high pollen. An analysis of emergency room visits in New York City during 1999 showed peaks in the number of visits correlated with high spring pollen counts, and is consistent with other work connecting allergy-induced asthma to increasing in hospital visits." -Climate Central 

Sunday, April 1, 2018

Severe Storms Possible Tuesday

Tuesday Morning Update:
The morning update has brought a slightly larger risk area and a new outlines tornado risk area that includes areas of Western Kentucky, Southern Illinois, and counties along the MS River in Missouri and Tennessee. That is shown in the second graphic below

Monday Evening Update:

Monday Morning Update:
These updates were anticipated further down in the blog from Sunday evening's post...The Storm Prediction Center has upgraded our area to a slight/enhanced risk for severe storms on Tuesday. Here is the latest outlook graphic as of Monday morning. 

Sunday Evening Update: 

A vigorous cold front will stream across the Local 6 are and Midwest on Tuesday bringing the threat for strong to severe storms. The subtropical jet stream will be supplying moisture and strong winds/lift by early Tuesday across the region. As an area of low pressure passes just to our north it will allow the return flow of warm, moist air at the surface which will become increasingly unstable during the late morning and early afternoon. A line of storms is expected to develop over the Ozarks of MO around noon on Tuesday then advance eastward through the afternoon. This line of storms will bring a damaging wind threat along with an isolated tornado or two. Daytime heating will be underway ahed of the front and may contribute to a few storms developing out ahead of the main line, especially over KY and TN. These storms will have a higher likelihood of producing large hail and even a few tornadoes. 
Overall dynamics favor the threat for damaging winds and large hail, storms with strong updrafts. Hail one inch or greater will be possible. Storms are expected to increase in intensity and coverage east to west through the afternoon. Here’s a look at model-projected radar for Tuesday Noon - 6pm. 
A very saturated ground will make it easier for winds to topple power lines and trees so remember to stay away from windows as part of your severe weather safety plan.

Flash flooding from heavy downpours will be possible with any isolated storms that develop ahead of the main line. Once the main line passes through the region by early evening, the severe weather threat should come to an end as cooler, drier air arrives. 
The following is the Storm Prediction Center outlook for Tuesday and will likely be upgraded to an enhanced or slight risk for the Local 6 area by then.