Looking At The Week Ahead: Changes Begin…
Our Saturday morning is dawning with pleasant conditions- filtered sunshine and temperatures in the mid and upper 60s for most. We’ll notice a couple of items today: 1.) increasing humidity as the day progresses and 2.) increasing storm chances later this evening. While most of the daytime hours should remain dry across central Indiana, that begins to change tonight. A cold front lies off to our northwest this morning and this front will slowly push southeast between now and Monday, passing the region Monday evening. Until the front passes, a more unsettled pattern can be expected. While it won’t storm the entire time over the next (3) days, a couple of rounds of hefty shower and thunderstorm activity can be expected. With a tropical air mass in place (PWATs flirting with 2″), locally heavy rain will accompany the storms.
The big story through the daytime today will be the heat. Most central Indiana neighborhoods will top out in the lower to middle 90s with heat indices approaching 105° at times. Take the heat seriously this afternoon and evening and ensure you have means to take frequent breaks if planning any time outdoors.
We’ll notice thunderstorms becoming more numerous for our friends in Illinois through the afternoon and evening, but central Indiana should remain mostly dry until tonight. Forecast radar products want to bring these storms into the state after the 7p to 8p time frame. We’ll keep close tabs on radar trends this afternoon.
(Again, with high moisture content, any thunderstorm that passes through your neighborhood will be capable of producing torrential rainfall). For that matter, the same story can be said with storms that develop Sunday and Monday, as precipitable water values will remain around 2″ until the front sweeps through the state.
Finally, the aforementioned cold front will sweep the state Monday evening. This will put an end to rain chances through midweek and allow for a refreshing air mass to blow into the region. How do highs in the upper 70s to lower 80s sound with low humidity? Overnight lows will be allowed to fall into the 50s during this time frame.
Overall, dry conditions should prevail until late next weekend when a secondary, even stronger, front will make a run at the region. We’ll ramp storm chances back up ahead of this expected front and the air mass behind the boundary in the Week 2 time period will be even cooler than we we’ll enjoy the middle part of the upcoming week.
Speaking of cool, the pattern continues to look vastly different as we put a wrap on the month than what we’ve grown accustomed to over the past couple of weeks. Note the dominant trough the models show setting up shop over the Mid West…
More specific to central Indiana, daily highs in the lower to middle 90s and overnight lows in the lower to middle 70s will continue into late next week. For the most part, this is a dry pattern, as well, BUT there will be a few exceptions.
Thereafter, additional isolated to widely scattered storm coverage is possible- primarily during the afternoon and evening hours, but more than not will remain rain-free. 7-day precipitation totals check in this morning in the 0.25″ to 0.75″ range.
Not only will this likely lead to a cooler second half of July, but should also offer up an increasingly active and wetter northwesterly flow for our immediate region.
Sunshine will increase for the second half of the weekend and highs will respond- mid 80s after a refreshing start Sunday morning.
While it’ll certainly turn more humid through midweek, the rain and storms will keep temperatures at seasonable levels. All of that changes once to Thursday and Friday as a building ridge of high pressure expands across the Ohio Valley.
This will limit rain chances and potentially offer up the hottest air of the summer. We expect 5-6 days of low-mid 90s for highs and oppressive overnight lows in the lower to middle 70s.
Thankfully, the hot dome will retrograde west and lead to “less hot” and increasingly stormy conditions after the first week of July. An active northwest flow pattern will take hold and provide an active time of things during this period.
An early look at next weekend shows general agreement with the GFS and European forecast models: drier air returning along with slightly cooler air. We’ll keep you updated!
By the time all is said and done late Monday night and early Tuesday, expect widespread rainfall totals between 0.50″ and 1″ with locally heavier amounts where the stronger storms track.
High pressure will build into the region through the midweek stretch and result in increasingly sunny and pleasant conditions. With a drier air mass in place, overnight lows will fall into the 50s through the midweek period.