Warm temps = warm nights

With a forecast like we have for this week it makes are job extremely difficult.  This morning when we came into work at 5 AM it was 81 degrees.



Cool season turf does best when high temperatures are 55-88 degrees, when the temperature gets above 88 then cool season turf starts to shut down and go dormant, save its carbohydrates and go in a state of rest until the temperatures cool down.  That is why areas in the south have warm season turf, which prefer temperatures above 88.  Well in our climate, we are suitable for cool season turf 10 month out of the year, but for the two months of July and August we should truly grow warm season grasses.  That would not work for the other 10 months, so we are left with trying to babysit cool-season turf through the super hot days of July and August.

When we have high temperatures in the mid 90's but it still cools off at night to 65-70 then we can still maintain cool-season turf and the grass gets 5-7 hours of cool temps where it can rest from all the stress during the day.  When our temperatures reach highs like they have forecasted this week, then the night time lows stay around 75 - 83, and in that situation the heat is putting stress on the turf 24 hours a day and it never gets to take a break.

This week you will see staff out syringing turf all day long with hoses, just to give it a cool down from the hot surface temperature of the sun.

Inversion Fog

For the last 3 weeks, and forecasted for the next 2 weeks, we have been stuck in a weather pattern with inversion fog and cloudiness starting in the early morning hours.

Just above the golf course looking down on the valley

This a very unique weather pattern due to our situation down in a valley, or hole.  All around us are higher bluffs that are about 800 ft in elevation above the valley floor.  The nights are clear leading to a cooler temperature and frost forming overnight.  Then the sun is visible many mornings right away, but as the temperature raises and moisture comes off the ground and atmosphere, a very dense fog layer forms, just like a cloud cover.

A view from the valley floor below the fog layer

It is known as Tule fog and is primarily found in the Grand Central Valley area of California, but with our rivers running through the valley floor adding to the moisture content, it is also very popular in our valley from fall to spring. It is compounded by our higher relative humidity in our area and also causes temperature inversions at lower altitude.

Right now this weather pattern is impacting the golf course by allowing frost to form most mornings and then fog is trapping in the cooler air, blocking out the sunlight and prolonging our frost delays with some a cool damp cloudy feeling in the air.  Typically it burns off by midday and then we have the same pattern the next morning.

Tule fog typically forms below 2000 ft in elevation and can be seen from the top as you drive the surrounding area above the fog.  Here are a few more pictures from above the valley on the highway that heads out of town.