Frost Advisory Tonight

Brrr!!! A frost advisory sounds so cold. Frost is likely across the area tonight with clear skies and light winds with low dew point temperatures. That combination of factors created ideal radiational cooling. That means that all the energy from the sun that was absorbed by the earth during the day escapes out into the upper atmosphere. That allows the temperatures to drop quickly and that is likely for tonight. The lake may help keep some locations a little warmer, but everyone will most likely get a frost.

The question that some of you may have is why do we have a frost advisory tonight when we had numerous nights with frost last night. The reason is because we have now entered the growing season. Last week we were not officially in the growing season. So what is the growing season? The growing season is loosely defined as:

Growing Season – the time period, usually measured in days, between the last freeze in the spring and the first frost in the fall. Growing seasons vary depending on local climate and geography. It can also vary by crop, as different plants have different freezing thresholds.

We have passed our average date of the last frost, however, as someone who has been here over a dozen years I don’t recommend planting the sensitive plants like tomatoes until after Mother’s Day.

If you are hoping for warmer weather it starts on Wednesday. Highs will be near 60 on Wednesday, 70 on Thursday, and 75 on Friday. It will be quite windy on Thursday and Friday. Friday will bring a chance of thunderstorms and we will have to watch closely for the possibility of severe weather. Right now, the conditions are not overly favorable.

The above image is from the Storm Prediction Center for Thursday’s chances of severe storms. I would not be surprised if southern Wisconsin is included in the day 3 outlook tomorrow. Stay tuned.

Rainfall should not be impressive as last weekend. The models are still in disagreement over what will happen with Friday’s storm. Some of the models are holding the rain into the weekend, but right now I’m buying the GFS model which clears us on Saturday morning leading to a decent weekend.

Here are the rainfall amounts expected by the Hydrometeorological Prediction center for Friday’s storm. The current forecast keeps us under an inch.

Thanks for reading. Have a great day.

Mark

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3 Responses

  1. GFS may be a hair fast on the progression of the front. Looking at past cycles, it does seem the SE ridge may want to hang around a bit. Also, short/mid range there is a trend for the PNA to be dropping and the NAO to be rising which would paint a trend toward SW troughing and SE ridging.

    • Thanks, Scott.

      Mark

      • Thank me if I am right..ignore me if I am wrong. 😉

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