A relative rarity in Maine; Portland got to 90 F yesterday with almost no sunshine. Sure it cleared out eventually, but the high temperature had already been hit despite the mid level cloud cover. Usually you need every ingredient to click to hit 90 F in this northern ocean influenced town, but the air mass was SO hot that sun was just an added bonus, we were going to roast either way. (I spent yesterday afternoon watching Matlock in my air conditioned living room. I wish I could play the "it's trendy because he just died" card, but I can't...I've loved me some Matlock for years. I blame my grandmother)
Today: Hot but not as brutal as Saturday. Mostly sunny skies will dominate the entire state until around 1 PM. At that point some clouds will stream into southern and western Maine in response to a weak upper level disturbance. That disturbance won't move through until tonight so just look for isolated showers near the ME/NH border and across the higher terrain. The rest of us stay clear and warm. Highs will end up in the mid 80s along the coastline with the southeast wind being the cooling factor. Upper 80s to low 90s are still likely away from the coast however, especially near Sanford and into Fryeburg.
Tonight: That disturbance drags through Maine, bringing more widespread showers and storms. This disturbance isn't all that strong so I think just moderate thunderstorms are likely to result. A line of storms is being projected to move through around midnight, however, so that might not be great for sleeping. Otherwise it's mild and muggy with most of the night spent in the 70s.
Monday: A few showers may still be leftover tomorrow morning, especially over Downeast Maine. After that, clearing will occur by mid morning allowing for a good deal of sunshine. Temperatures will respond, reaching the mid to upper 80s in most spots. There is an ISOLATED chance for a pop up thunderstorm in the afternoon but I'm putting the chances at around 15%.
Tuesday: Hot again. Mostly sunny skies will provide the spark to push much of Maine back into the 90 F range. Also, the coastline should be able to warm up a good amount before a late day sea breeze takes over.
Wednesday: The heat part is OVA. A cold front drags through with much cooler and drier air. The computer models differ quite a bit on the timing of the front: some have it in the morning while others push it through during the afternoon. That will make a HUGE difference in our forecast as an early passage means weak showers and a later passage will likely spell severe weather due to daytime heating instability. Right now I'm going to lean on the earlier solution because my favorite models are locked into it.
Cooler, drier and beautiful for Thursday/Friday/Saturday. I call this Chamber of Commerce weather. Upper 70s to low 80s with tons of sun.
By the way, the "it's trendy because he just died" is an established phenomenon. Just check out the iTunes bestsellers list after the death of MJ. It's even worse in rap, you actually HAVE to get shot to be in the top 5 all time it seems. Not just shot in the foot or something either, that doesn't count.