Why So Rainy?

May 5th, 2013 at 9:46 pm by under Weather

If you thought last week was rainy, just wait until you see all the rain chances in the forecast this week.  Meteorologist Jeff Edmondson wrote a blog this morning talking about how much rain we could see over the next few days. I am expanding on his blog and answering the question “WHY?”

The graphic below shows the current weather pattern across the U.S.

Weather Pattern

Current Weather Pattern

There are different types of atmospheric blocking patterns that can develop. The one above is called the Omega Block because it resembles the Greek letter Omega. This blocking pattern can can cause the weather to “repeat” several days in a row. High pressure is dominating the middle of the country while an area of low pressure is bringing unsettled weather to the West Coast and to the Southeast.

Satellite/Radar

Satellite/Radar

High pressure will typically bring in warm and dry weather, while low pressure will bring in cool and wet weather.

The area of low pressure sitting over Alabama was over the Midwest last week. This was the same storm system that brought the snow and the record cold to the Mid-West and the Southern Plains. The air has modified since then, so we are just going to see rain and cooler weather for much of the upcoming work week. This Omega Block will break down on Tuesday, but the low pressure across the Southeast will become cut-off from the jetstream and lose its steering winds. This will cause it to slow down and sit over the same area for days. This low will sit over Hampton Roads the next few days and bring us the chance for showers and maybe even a few thunderstorms Monday through Thursday. Here are the latest rain chances.

Rain Chances

Rain Chances

The storm system will finally move offshore on Thursday. Models usually kick out these upper levels low too quickly. Right now, it looks like Friday will be dry. But if this system slows down any more, then we could be adding some rain chances in on Friday. Either way, our long-range models have another storm system moving in sometime this weekend. So get ready for a wet week ahead!

-Meteorologist Tiffany Savona

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