TULSA, Oklahoma - Active weather will soon unfold across the plains.  A powerful upper level trough currently across the western U.S. will influence eastern Oklahoma weather Saturday with thunderstorm chances and severe weather threats. 

This first system will eject out of the area late Saturday evening with another strong system approaching the state early next week resulting in severe weather and heavy rainfall threats both Monday and Tuesday.  Already saturated soils and water basins will be impacted with additional heavy rainfall that may lead to some flash flooding potential during the Monday and Tuesday event followed by a few days of additional river and stream flooding issues across eastern Oklahoma. 

The pattern both today and Friday will feature warm and dry conditions for the eastern half of the state along with increasing south winds and highs in the upper 80s. 

Storm chances will first begin Friday across extreme western Oklahoma and the high plains of Texas.  As the main upper level system draws closer to the desert southwest, pressure falls across the Rockies will result in a surface low developing across southeastern Colorado or far southwestern Kansas.  A dry line will become established south of this surface low separating moist and unstable air to the east and dry stable air to the west. 

The dry line is expected to be positioned just east of Amarillo by Friday afternoon as the strong winds aloft move across this region Friday afternoon and evening.  A few scattered storms will attempt to develop through the capping inversion.  Any storms that form will be severe with very large hail and damaging winds along with a tornado threat.  These initial storms should be supercells, but a few additional storms could develop into a few small clusters that would move east-northeast by late evening into central Oklahoma.  A few of these may persist pre-dawn into eastern Oklahoma Saturday morning with some severe weather threats. 

Sometime early Saturday morning additional storms are likely to develop across Texas as stronger winds aloft round the base of the main upper trough as it draws closer to the plains.  Some of these storms may develop or move into southeastern to eastern OK Saturday morning with a severe weather threat despite the early morning period.  A complicating factor may be the southward expansion of storms into central and east Texas acting to slightly disrupt the flow of moisture across eastern Oklahoma. 

Basically, the impact of morning storms near or southeast of the Tulsa metro may have an impact on the severe weather potential for Saturday afternoon and evening.  

Regardless of the different scenarios, the threats for all modes of severe weather will remain for the Saturday system with at least two windows for some development, including the morning hours and the latter half of the afternoon through evening.  This system should be exiting pre-dawn Sunday with improving and dry conditions Sunday. 

This one-day respite will quickly end with another strong system nearing early next week.

The Monday and Tuesday system will also have the potential for some severe weather threats and should also increase the potential for heavy rainfall across northeastern Oklahoma.  The exact timing will continue to change many times before early next week, but most data support increasing storm chances Monday morning to midday across southwestern and western Oklahoma spreading north and east into Monday afternoon and evening. 

The main system will be ejecting across the state Tuesday with additional storm chances before ending late Tuesday night or early Wednesday morning.  Both medium to long range models depict deep and persistent moisture across the state.  Neither output is particularly good news for our saturated soils and overflowing lakes, but the EURO data would produce higher amounts.  Flash flood watches and river flood watches may be required.  

Severe weather threats will also be of concern with all modes of severe weather being possible. 

The pattern may bring a few days of relative dryness late next week.

Timeline and specific severe weather potential will more than likely undergo some changes between now and Saturday.  

Thanks for reading the Thursday morning weather discussion and blog.

Have a great day!

Alan Crone

KOTV