Alan Crone's Weather Blog: Heavy Rain Headed To Oklahoma

Wednesday, June 17th 2015, 4:16 am
By: Alan Crone

Tropical depression Bill is located this morning (3am) across part of central Texas near Waco.  This tropical system is moving northwest and will move into part of north TX later this afternoon and into south-central or southern OK late tonight.    The remnant low pressure area will move across portions of eastern OK Thursday and should exit the area either late Thursday night or very early Friday morning. 

A few bands of tropical downpours are noted well north and northeast of the circulation and should develop across part of northeastern OK early this morning.   As the remnant low draws closer to the Red River Valley this afternoon, additional bands of showers and storms will also develop and move into south-central, southern, and eastern OK.    As the low pressure center enters southern or south-central OK by early afternoon, moderate to heavy rainfall will be encompassing a large area of southern and eastern OK.   This period from early late afternoon through Thursday will represent the highest time period for the heaviest rainfall to occur.   Flash flood watches are posted through Friday.   Model output precipitation forecasts in the range of 4 to 7 inches of rainfall seem likely with some localized totals nearing 8 to 10 inches possible.  The exact track and path of the remnant low may still change and impact where the heaviest rainfall occurs.   High water levels are likely to occur again across a number of lakes, creeks, and streams across southern and eastern OK during this event.   Major rivers are also expected to flood during and after the tropical system exits the state.  

The low-level wind field is supportive of some tornado potential near and northeast of the circulation center later today into the evening hours as the low enters southern OK.  Tropical tornadoes are usually weak and short-lived and the chance for this type of weather will remain low.

Most data support the main circulation exiting the state by early Friday morning.  If the system slows, we'll add some additional probabilities for early Friday morning across eastern OK, along and east of highway 69.   At this point, the probabilities for Friday will remain near 20%.

The remainder of the 7 day period feature very warm and humid conditions with temperatures this weekend in the lower 90s.   Heat index values Saturday could approach 100.     A weak boundary may briefly approach northern OK and southeastern Kansas late Sunday night or early Monday morning with a slight chance of showers or storms, but this chance will remain near or less than 10%.   We have elected to keep this low chance off the 7 day planner.

Temperatures today will stay in the upper 70s and lower 80s along with increasing southeast winds at 10 to 20 mph as the tropical system nears the region.   Wind speeds are expected to increase later tonight in the 20 to 35 mph range.   These speeds should remain into Thursday but winds will change direction from the southeast to the northeast and eventually northwest later Thursday as the circulation moves across the region.  

Residents located in the flash flood watch areas should remain alert to rapidly increasing water levels and seek high ground in the event flooding occurs or is likely.   

Thanks for reading the Wednesday morning weather discussion and blog.

Have a safe day.

Alan Crone