10/27 – Rob’s “Sunny & Cool” Thursday Morning Forecast
The next in a series of upper disturbances extended from the Canadian Prairie Provinces to near Salt Lake City to Baja California. This is beginning to turn our upper level flow SW’terly. At the surface, high pressure centered over Lake Michigan essentially controlled the weather over the entire Mississippi River Valley. The upper disturbance over the Inter-mountain West will continue to move eastward into West Texas by midday Friday. With the upper flow becoming more southwesterly, upper level moisture should start arriving in our area Friday morning. This will cause an increase in upper level clouds, with that layer gradually thickening/lowering. However, there won’t be much of an onshore wind component at the surface until Friday afternoon.
Basically one weather event for the long term forecast period, and that will be Friday night into Saturday. The disturbance over West Texas Friday afternoon is expected to track to near Shreveport by midday Saturday and to somewhere near St. Louis on Sunday. This system will be taking on a somewhat negative tilt as it approaches the Texas-Louisiana border Saturday morning.The event window Saturday is indicating that offshore convection would cut off the best moisture and instability over much of the local area. That scenario would have a swath of significant rainfall associated near the upper low, and another over the Gulf. Areas that do get into the warm sector will have the opportunity to see some strong t-storms with shear profiles more than sufficient for severe weather, and potentially a couple inches of rain. Bottom line…still enough uncertainty in specifics to pinpoint a threat area for severe weather and/or excessive rainfall other than to say that there is at least potential for it. As the storm system continues to lift away from the area Saturday night, conditions should dry out quickly. Likely to see wrap around cloud cover, but little, if any, precipitation central Mississippi and further north of the area on Sunday.