Will Willa wash out our weekend?

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If you’ve been paying attention to the news over the last couple of days, you’ve probably heard about Willa, the major hurricane on track to hit western Mexico today. Yesterday, she was a category 5 storm on the Saffir-Simpson Hurricane Wind Scale. As of this writing, Willa is a category 4 storm and still extremely dangerous. She may weaken a bit more before making landfall, but as we’ve seen here with Florence, weaker winds do not mean the storm is any less dangerous. The Saffir-Simpson scale measures wind speed, not rainfall or storm surge.

Fortunately – for lack of a better word – Willa will be a fast-moving storm tracking across Mexico and falling apart as she crosses the Sierra Madre mountains. Unfortunately, she’ll cause flooding and landslides as she goes. What little is left of her vorticity – the rotation within the low-pressure system – and her moisture will cross southern Texas and move across the northern Gulf of Mexico to link up with a frontal zone on Thursday. Then, the whole mess will head across the extreme southeastern states and into the Atlantic to roll up the United States coastline toward eastern Canada.

Combining a sort of cold air damming situation in place over our region with a developing coastal low Thursday night and Friday will give us increasing rain chances late Thursday. By Friday and Saturday, rain will be likely, and it could be heavy at times while the storm moves along North Carolina’s coastline. Then as it pulls farther away on Sunday, we may see some breaks in the clouds, and the rain will become more scattered in nature.

Saturday forecast map

The forecast map from NOAA’s Weather Prediction Center for Saturday morning showing a developing low pressure system off the coast of North Carolina.

By Tuesday morning, the system will no longer be affecting us, but it will likely leave up to two inches of rain in its wake here in Wake Forest. Compared to other storms this year, that seems pretty mild, but it’s still enough to ruin outdoor plans on Friday and Saturday.

In addition to the clouds and rain, our temperatures will be well below normal through the period. Our 30-year average high for this week is around 71 degrees and our average low is in the upper 40s. By contrast, on Friday, depending on the track of the developing coastal low, our afternoon temperature may struggle to make it to 50 degrees. Saturday and Sunday should be a little warmer each day, but stay well below normal.