As attention turns to the 4th of July holiday, there aren’t any changes to the ongoing idea of a significant heat wave gripping the region.
A strong ridge of high pressure will anchor itself over the Ohio Valley during this time frame and help power a big time period of hot and mostly dry weather. It’s the type of pattern that has legs to promote multiple days of highs in the middle to upper 90s across central Indiana. With tropical dew points in place, overnight lows won’t be allowed to fall much below the middle 70s during the height of the heat wave. Heat indices will rise into the lower 100s to near 110° at times.
Take this period of heat seriously. With many area festivals, firework shows, and events going on during the holiday week, it’ll be important to have a means of keeping cool. Simply put, this kind of heat wave doesn’t come around every year (and thank heavens for that).
With the hot dome centered over the Ohio Valley, it’ll really help to limit shower and thunderstorm chances. That’s not to say isolated coverage of cooling thunderstorms won’t occur on occasion during the afternoon and evening, but widespread rain of significance won’t be around during the period. Thankfully, the recent wet pattern and additional storm complexes coming in Tuesday into Wednesday have and will help surface moisture levels. Had we not seen the recent wet shift over the past couple weeks, you could easily tack on an additional 3° to 5°…
For those longing for the cool, crisp days of fall, hang in there. Heck, it’s only 69 days until my beloved Auburn Tigers tee it up and kick it off against the University of Washington… I am one that says “bring it on!”
Despite cooler (still mighty humid) temperatures arriving, the overall pattern won’t change significantly into late week and this weekend. With the frontal boundary draped across the Ohio Valley, periods of showers and thunderstorms will remain in the forecast. At times, disturbances will track along the boundary and lead to increased coverage of storms. Perhaps Thursday and Friday will serve up the greatest coverage of thunderstorms as a surface wave moves out of the central Plains into the Great Lakes.
The combination of a juicy air mass and a stationary boundary draped overhead spells a flash flood risk. The lack of any sort of overall steering current suggests the potential of thunderstorms that may train over the same communities at times. As mentioned earlier, precipitable water values (PWATS) will approach and exceed 2″ and this will support torrential downpours at times.
Officially, we think the upcoming 7-day period will deal out widespread 2″ to 3″ rainfall totals across central Indiana, but there will be locally heavier amounts where thunderstorms train.
A cold front will drop south early next week and help increase overall coverage of showers and thunderstorms late Monday into Tuesday along with provide relief (at least temporary) from the hot, humid conditions. Temperatures will settle back closer to average by the middle of next week.
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!
Eventually these storms should pick up momentum and head off to the southeast later tonight.
An increasingly muggy air mass will take hold of the region as we close the work week, with dew points approaching 70° at times. The term “air you can wear” comes to mind. As impulses of energy interact with this tropical air mass, thunderstorms will blossom- particularly in the afternoon and evening hours.
Looking down the road, a “sticky” summer feel will remain intact through next week, but changes are brewing in the longer range. These changes would support a cooler regime developing just past mid-June (in the 10 to 15 day time frame). While the duration is up for debate, it’ll be nice for at least a few days of cooler air…
