A cold front is slowly sinking south and will feature a weak wave of low pressure that will track along the boundary Tuesday. The end result spells for increased chances of showers and thunderstorms across central Indiana over the upcoming 24-36 hours.
Initially, we expect an area of thunderstorms to push south and potentially impact north-central portions of the state later tonight. The latest high resolution NAM forecast radar gives us an idea what the radar may look like late tonight- just after midnight.
Some of the storms across the northern third of the state may “pulse” to severe levels this evening, including the potential of large hail and damaging winds. (This complex will weaken as it surges south later tonight).
As we turn our attention to Tuesday, scattered to numerous showers and thunderstorms are expected, especially during the afternoon and evening hours. A few strong storms are possible, including locally heavy rain.
Eventually, drier times will return by mid-week. Beforehand, most central Indiana rain gauges should receive somewhere between 0.50″ to 1″ of rain. With a rich, tropical airmass in place, there will be some locally heavier totals.
Image courtesy of weathermodels.com
Image courtesy of weathermodels.com
As the cold front moves south during the midweek stretch, drier times will return Wednesday and Thursday. With that said, the drier regime won’t last long, as a cut off upper low “mucks” things up over the weekend. While it certainly won’t rain the entire time, daily rain chances will return late Friday, continuing throughout the weekend. There’s no need to cancel any outdoor plans, but have the rain gear handy, as you’ll likely need it at times throughout the weekend.
A “cut off” upper low will impact the region this weekend. Image courtesy of tropicaltidbits.com.
Speaking of rain and overall unsettled times, the pattern sure looks active around these parts into the mid and longer range. More on that in future updates…
Longer range data suggests wetter than normal times throughout the Ohio Valley mid and late August. Image courtesy of Tropicaltidbits.com.
As we look ahead, our weekend weather will continue to be dominated by a “cut off” area of low pressure. As it meanders around the region, shower and thunderstorm chances will remain. Aerial coverage of rain will reach greatest heights during the afternoon and evening hours today and Sunday. With the colder air aloft, don’t be surprised if a few of the stronger showers produce hail.
Additionally, highs today will run close to 10° below the average high of the mid-80s.
Longer term, the NEW JMA Weeklies suggest the worst of the summer heat is now behind us as they keeps the Weeks 3-4 time period unseasonably refreshing…
Part of the reason behind today’s severe weather has to do with an overall pattern shift. An intense short wave trough (especially for this time of year) will dig into the Great Lakes and Ohio Valley. At the surface, an area of low pressure will track from southern WI (this morning) before “cutting off” over the Ohio Valley this weekend. Additionally, a couple of frontal boundaries will swing through the state- the most potent being the boundary that surges east this afternoon and evening. The combination of ingredients spell trouble across at least a portion of the region- especially from Indianapolis and points south and east this afternoon and evening.
The Storm Prediction Center currently has a ‘Marginal’ risk of severe weather for portions of the state. It wouldn’t surprise us if a portion of this risk area is upgraded to a ‘Slight’ risk with future updates. The primary concerns? Stronger storms may include damaging winds and large hail.
Storm coverage will diminish during the day Friday with a drier air mass taking hold by evening. We’ll really notice a reduction in humidity Friday night and that more refreshing feel will remain intact through the weekend. Dew points may even fall into the 40s by Saturday morning! Many central Indiana neighborhoods can expect to settle into the mid and upper 50s for overnight lows Saturday and Sunday mornings.
Dry weather will be with us as high pressure remains in control of the period this weekend into early next week.