As drought expands, weather pattern looks to shift to cold, rainy to end October

By: Lead Forecaster Daniel Crawley

Good Thursday morning to everyone, it has been a very stagnant weather pattern in recent weeks and that has resulted in a growing drought across the Carolinas. A new drought update should be posted any moment.

Good news…there are signs of a more unsettled weather pattern going into the final week of October. And anytime you have rainy weather this time of the year, you also stand the change of it being quite chilly as well.

Latest water vapor imagery shows a huge trough across the eastern US delivering cool, dry air into the Carolinas. meanwhile an upper level feature has come on-shore the coastline of California. Both of these features may work in tandem to create the weather changes next week.

If you look (video below) at the 500 mb pattern going into the weekend, the large eastern trough slowly moves off the New England Coast. A blocking high will move across Hudson Bay helping to lock in northwest flow. That block will also force the southwestern upper low to move slowly east instead of lifting northeast.

There are signs of the southern wave stalling out and waiting for additional upper-level energy to re-energize the dynamics.

For the sensible weather, expect a ton of sunshine through Saturday across the Carolinas. Sunday will be a day of transition as moisture could roll in during the nighttime hours and once we get to Monday, moisture and upper level dynamics become stuck over the Carolinas.

Overall, this looks to be the best chance at wet weather in quite a while. Another thing of interest is that surface high pressure will be delivering dry air at the low levels through Sunday. So if we do end up with moisture coming in early next week, it will be overriding a polar airmass. This has all the makings of a cold air damming event and it could be quite stout as some guidance is struggling with temperatures for Monday and Tuesday of next week. The Euro for example wants to keep upper 40’s locked in across Western North Carolina.

We are not quite ready to go that aggressive in our 10-Day forecasts but its an option that does remain on the table as we get within five days of the timeframe.

A National Blend of Models are showing a good chance of at least 1 inch of rain going into next week. Some individual models show 2-inches or more. We’ll definitely adjust our forecast amounts as we get closer.