While cooler and wetter conditions dominate now, thoughts are shifting ahead to the all-important 4th of July time period.
Models are in relative agreement that a sprawling upper level ridge will park itself over the Ohio Valley, leading to a higher than normal confidence for a medium to longer term forecast period.
The end result would be anomalous heat and a drier pattern, as a whole, as we transition through the early stages of July. Heat to the magnitude of what we experienced last weekend isn’t off the table with such a similar pattern.
Looking ahead, thankfully, one of our more trusted longer range computer models (JMA Weeklies), shows the pattern relaxing as we move into mid-July. The model shows the heat backing west and a more active northwest flow (wetter pattern) returning here…
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.