Warm, calm conditions have continued for many days today as a strong ridge still controls much of the United States.
Temperatures 30 degrees above average exist in the northern parts of the country today. The exceptions to this delightful spring weather are the Gulf Coast and the Pacific Northwest, as we’ve discussed on multiple blogs this week.
All good things must end, though. By Friday, a large-scale system will be rolled out across the country, bringing unsettled weather and the potential for major storms.
As a trough rolls eastward, a low surface is expected to form in the lee of the Rockies. Before this low, abundant moisture will move to the southern/central Delta.
While the details are still unclear, it looks likely to be a classic dry line setup.
As the lowlands developed and strengthened, moisture flowed northwards in front of the front. Behind that, the dry line (the boundary between drier air and wetter air) will be sharper and move east. This will provide a lifting mechanism for the storms to shoot out.
Despite plenty of low humidity, this additional lift will be needed as a strong limit reversal is forecast.
The extra lift will provide enough thrust to allow a few storms to break through the aforementioned limit and quickly take advantage of the atmosphere before it settles back into the night.
Pulling a sound from the area of greatest risk along the OK/TX boundary, we can get an idea of what might happen in terms of expected hazards.
- As mentioned, a strong limit is present. Extra humidity/heating/lift will be required to pass.
- Speed shears are not great, but low-level directional shears do. If the storm can break the lid and hold, a tornado can occur.
- Above the limit, a lot of CAPE is modeled, as well as a rather high error rate. This will help the storms strengthen quickly and also pose a huge hail threat.
- Dry air is available to entrain the updates in the middle floors. However, the wind speed in this class is not so impressive. Any wind threat could be further below unless stronger mid-range wind speeds materialize in later projections.
For now, Friday’s severe weather threat that seems to present the main risk is very heavy hail with the potential for some damaging winds and a few tornadoes. It will focus better the next day or so.
This threat will extend into the Mid/Lower Mississippi River region on Saturday, but details are still being worked out. We will discuss this in a few days.
- The return to the activity pattern happens as the weekend kicks in. Major storms are possible in the Plains on Friday, the Mississippi River Valley on Saturday, and potentially the Ohio Valley/Mid-Atlantic Ocean on Sunday.
- Track forecasts for your specific area so you know when to prepare.
- Make sure your alerts are up and running if you need them.
- Alert your friends, alert your family. If you know someone who is in an at-risk area, notify them of the possibility of severe weather so they can prepare as much in advance as possible.
About the author
Meteorologist – ’22 Mississippi State Writer for Weather.us and Weathermodels.com. Focus on weather communication. BoyMom x1, CatMom x5. Twitter: @MegGulledgeWX