Technical Discussion

Synopsis: 

Scattered showers and thunderstorms will continue to develop over parts of the state until night falls.  Expect a mix of sun and clouds tomorrow and Tuesday before a cold front passes through the region late Tuesday into Wednesday.  This frontal passage will bring the opportunity for some rain showers through Thursday.

Short- Term:

We forecasted the chance of scattered thunderstorms over the region for the remainder of the day, mainly until night falls and the day time heating diminishes and thus much of the potential for instability decreases. The 1500 UTC SREF runs show the probability of CAPE exceeding 500 J/kg and even over 1000 J/kg to be moderately to quite high for the next few hours, particularly over the southeastern and south-central portions of the state. Most importantly, some convection has already initiated over portions of the state over the past few hours, demonstrating that atmospheric conditions are already favorable.  The 1200 UTC run of the WRF-NAM model shows the most significant rain or thunderstorm activity moving out of the southeast region and thus the state by the middle of the night, and only spotty showers at best tomorrow across the state.  Both the 1200 UTC runs of WRF and GFS suggest, in the relative humidity fields, that there will still be some moisture at most levels and thus some clouds over the state tomorrow.

Long-Term:

Both the WRF and GFS runs project that the associated cold front from a low pressure system currently hovering in the upper Midwest/Canadian region will pass through the state as Tuesday progresses, bringing another opportunity for scattered showers.  The 900 UTC run of the SREF precipitation ensemble shows precipitation moving into the state by Tuesday night.  The SREF plumes, as would be expected, project similar, and are not forecasting a vast amount of precipitation through Thursday, so we are not expecting a significant rain event. Behind the passage of the cold front, cooler conditions will build in for the latter half of our forecasting period.