A Chance of Storms

Monday, June 11th 2012, 5:43 am
By: Alan Crone

Expect a humid morning and a warm afternoon with a chance of storms today.  Some may be severe.  Highs in the upper 80s to near 90s will be expected.

A cold front is slowly advancing southward from the southern Kansas area this morning while the western portion of the boundary as already entered northwestern OK.  This boundary will slowly slide southeast during the day bringing a chance of storms to the region.  If storms form or move into your area they could be strong to severe with large hail the main threat.  The models have varied solutions regarding the timing and onset of precipitation.  There is a chance of storms forming this morning across southeastern Kansas moving into far Northeastern OK by 10AM.  Other models bring the front across the area later this afternoon before stalling across southern OK this evening.  A layer of warm air aloft was noted in last night's upper air sounding data.  This CAP may be sufficiently strong to limit storm coverage to the far eastern part of the state but we'll keep a decent mention of showers and storms in the forecast for most of the area.  Specific model output from the HRRR and NSSL 4K do not develop a large amount of thunderstorm activity with this system but does hint at some convection across extreme NE OK, SE Kansas, and NW Ark during the mid-morning hours.  Some of the operational models do hint at a wider spread of storm development.  I'm leaning toward a 30 to near 40% chance of storms for today and this evening.

Tuesday through Wednesday is as clear as mud in the data.  The EURO is the dryer of the model suites with the NAM on the wet side.  I have taken a blended approach with the pops for Tuesday and Wednesday meaning about a 30% chance of Tuesday storms, with an increase to near 40% for the Wednesday period as the frontal boundary begins a northward retreat across the state. 

Thursday through the weekend will be characterized with a typical June atmosphere including a stout low level moisture field but with relatively weak wind fields aloft over the state.  These conditions will promote isolated late afternoon to early evening storms across eastern OK and west Arkansas almost every day through the extended.  The coverage will be very low and we'll not include a specific percentage of pops on the 7 day planner past the Thursday morning time period.