9/30 – Rob’s “Changing Pattern” Friday-Eve Morning Forecast
The airmass remains very moist, with climatologically above the 90th percentile for this time of year. No real indications of any significant drying through Saturday, as even then, moisture levels remain elevated. A disturbance coming out of the base of the western US will use the moist airmass to develop scattered convection during the daytime hours each day. Friday’s convection may be a little later developing than today’s or Saturday’s, as it appears the disturbance will arrive later in the day, and convective temperatures will be a little higher. As instability wanes with the loss of heating each day, most of the overnight hours should be dry each night. There’s at least a minor concern for very heavy rainfall across about the western half of the area today, considering how high the moisture values are.
Another disturbance will move through the southern plains on Sunday as the SE flow will bring gulf moisture ahead of the disturbance on Sunday leaving the chance for scattered showers and storms to continue through the end of the weekend. Monday is expected to continue to be unsettled as a frontal boundary slides into the area with the potential for strong to severe thunderstorms with a pre-frontal trough potentially bringing a large area of convection. Temperatures expected to eventually return to near or possibly below normal with drier air and subsidence expected as a low-pressure tracks to the east of the forecast zones.