7/29 – The Chief’s “Typical Summertime Pattern” Friday Afternoon/Weekend Forecast
Scattered shower/t-storms this afternoon will see a gradual transition of dry air replace deep moist air this weekend. Then another transition of this dry air to the deep moist air again by late Sunday into Monday. The dry air will lead to lower precip chances but also cause higher downburst potential since this dry air layer will max at or near Saturday afternoon/evening into Sunday. As moisture values climb again by late Sunday, the dry air exits and we get back to a normal summer diurnal rhythm. The dry air is moving in from the western periphery of the Bermuda ridge and is currently located over south Florida. This is very evident in moisture fields. When the mid-level dry air moves in, it should push most activity north and NW. But where this air meets the deeper moist air is where the strongest downbursts could occur. This happens again as the deep moist air replaces the dry air Sunday.
An area of low pressure will rapidly move across the southern gulf over the weekend while a stalled upper trough remains over the central CONUS. The gulf coast will be caught in between these two systems with the interaction between the two causing a subsiding drying pattern at least temporarily. As the low pressure moves to the western gulf, this upper subsiding profile weakens and moisture is able to take its place for the start of the week bringing the daily chances of showers/t-storms back to where they have been for several weeks now.
A low to mid level weakness develops along the gulf coast and is oriented east- west by Monday. This remains through at least mid-week and could become a focus for some fairly heavy precip each day, especially where convergent flow develops into this boundary. There are some indications of an T-STORM COMPLEX or two developing and moving in the easterlies back toward the NW gulf by the end of the week.