First off, for tonight, one more relatively pleasant night, before the torch begins. Surface humidities are low, so temperatures should be able to fall quickly after sunset. There should be a wide range of low temperatures tonight, especially for late July. In the normally cooler areas, such as sheltered valleys and the Northern portions of the state away from Hartford, temperatures will be in the mid to upper 50s. In the warmer locations, such as in and near the larger cities, and southern locations, lows will stay in the upper 60s.
For tomorrow, temperatures and humidity will begin to creep up. Tomorrow will still not be all that bad, as the real heat begins Saturday, but it will be noticeably more uncomfortable in the afternoon tomorrow than the past two days. High temperatures tomorrow should be generally in the upper 80s statewide, except for mid 80s in the Northwest hills.
For tomorrow night and Friday, temperatures continue to creep slowly upward. However, a backdoor cold front nearby will keep temperatures at bay a bit and likely also kick off a round of thunderstorms. Tomorrow night's lows will be similar to those of tonight in the warmer locations, but significantly warmer in the cooler locations, as they become more uniform. Friday's high temperatures will be similar to those of Thursday, but there could be a small corridor of 90-degree temperatures, away from the immediate south coast, and not too far north. Maybe a 10-mile wide corridor, beginning around the Merritt Parkway, then north for ten miles or so. The next issue will be thunderstorms along this frontal boundary. The Storm Prediction Center has placed most of the state in a Slight Risk of Severe Thunderstorms. Expect the potential for strong gusty winds and possibly even hail. The best chance of thunderstorms appears to be within a few hours of midnight.
In the longer term, temperatures will be rather tricky, as it appears that Connecticut will be right on the edge of very hot (100 degree) type weather, and coastal influence with normal temperatures. At times, the heat ridge will flex its muscle, and send at least a tempered from of that heat into Connecticut. At other times, the maritime air will win out. In between, there should be rounds of thunderstorms. Timing these features will be difficult. In addition, there will be times when a slight difference in the position and strength of these features could mean a significant difference in temperatures. For now, the two very hot days appear to be Saturday and Monday. This is my best interpretation at the moment of a rather difficult extended period.
Saturday: Sunny and hot. Highs 90-95.
Sunday: Sunny and not quite as hot. Highs approaching 90. Warmest areas should be similar to the areas I outlined in Friday's forecast.
Monday: Cooler with increasing cloudiness. Highs 80-85. The next frontal system brings a chance of thunderstorms at night.
Tuesday: Clearing and hot. Highs around 90.
Wednesday: Sunny and not quite as hot, with highs in the mid 80s.
In the longer range, there doesn't look to be too much of a change from the pattern outlined through much of this forecast, as the Western Atlantic Ridge dominates the pattern. The overall themes will once again be when the WAR dominates the pattern and when a more maritime high pressure system sets up. Of course, along the boundary between the two, there will be areas of thunderstorms.
Here is a map, outlining the potential thunderstorms for Friday night.
Next, let's look at the possible thunderstorms for Monday night.
Anyway, that's all for now! Have a great rest of your week!