10/25 – The Chief’s “Severe Potential” Tuesday Morning Forecast
While isolated showers are streaming north across the local area, the activity will ramp up through midday. The upper disturbance is becoming somewhat negatively tilted early this morning, and is expected to lift quickly northeast to between St. Louis and Memphis by this evening, before moving through the Ohio River Valley overnight and Wednesday into the eastern Great Lakes. The trailing cold front should be approaching our area around sunrise, moving across the area during the morning and early afternoon hours today.
There will be a 2 hour window for the potential for severity. Stability of the atmosphere will be conducive for at least some strong thunderstorm development, mainly over southwest MS and areas to the north. Points further south are somewhat less favorable, but the threat is definitely not zero. While most convection allowing models show areal coverage of storms diminishing as the front approaches and moves east of Interstate 55, the latest runs show potential for an increase in coverage again as the boundary crosses the Pearl River early this afternoon. Main threats in any case will be damaging winds, with instability values more supportive of tornadoes mainly north of our area. Timing hasn’t really changed much, with thunderstorm line somewhere between Interstate 55 and the Pearl River by 12 PM. Dry weather on tap for tonight and Wednesday with cooler temperatures.
Wednesday night and Thursday should be fairly quiet, with brief high pressure moving across the area. Moisture will initially be limited with low level winds not turning onshore until during the day Friday. There looks to be about an 18 hour period beginning Friday for the best opportunities for showers/storms. This system will likely be the best opportunity we’ve had for significant precipitation in the last 6 weeks or so.