textproduct: Caribou

WHAT HAS CHANGED

-Issued Heat Advisory for Bangor and surrounding areas for Friday afternoon.

-Chance for showers early next week.

KEY MESSAGES

1) Hot and muggy Friday approaching heat advisory levels over Downeast and the Bangor Region.

2) Scattered showers and thunderstorms late this week. Some severe storms are possible.

3) Scattered rain showers and thunderstorms early next week.

DISCUSSION

KEY MESSAGE 1...Hot and muggy Friday approaching heat advisory levels over Downeast and the Bangor Region.

KEY MESSAGE 1 DESCRIPTION... Hot and muggy temperatures expected again tomorrow with highs climbing near to possibly above 90. Dewpoints will also climb to around 70 south and east of State Route 6. This will produce heat indices or feels like temps in the mid 90s for several hours tomorrow afternoon. This will mostly likely affect lower elevations in southern Piscataquis and central Penobscot counties, as well as the Bangor Region over toward Calais and down into MDI. The record high temp at Caribou on Friday is in jeopardy with a forecast temp of 88. The record is 89 degrees from 2022. All other temps are forecast to fall about 3-5 degrees short of their records.

Ultimately, the heat indices will depend on how warm it is able to get tomorrow. The potential of a storm or two developing on a weak surface trof in that area during the afternoon may limit heating though not all of the guidance is showing development.

Over the weekend, temperatures will be not quite as hot mainly due to increased clouds. That said, it will still easily be warmer than average, with nighttime temperatures staying especially mild. And it will still be muggy over the weekend. Uncertainty in temperatures over the weekend is just how warm it gets and that will depend on the amount of clouds and showers/storms.

KEY MESSAGE 2...Scattered showers and thunderstorms late this week. Some severe storms are possible.

KEY MESSAGE 2 DESCRIPTION... Low pressure system slowly moves northeast through Canada. Associated cold front swings through on Friday night, through Maine by Sunday. There is some instability ahead of this cold front, with the best instability and moisture on Saturday. Models continue to align with 1,500 2,000 J/kg of CAPE, good low level lapse rates (roughly 8C/km), and plenty of precipitation. Soundings are moist, with classic long and skinny CAPE throughout most of northern and eastern Maine. PWAT values around 1.8 2.0, which is well above the Saturday daily record of 1.7". Continuing to keep the threat of thunder inland on Saturday, as a seabreeze off of the cold Gulf of Maine waters should stabilize and keep daytime high temperatures on the lower side along Downeast Maine coastline through the weekend. Storm motions based on Corfidi vectors seem to have trended a bit slower, but still not anticipating flash flood concerns. Three hour flash flood guidance is roughly 1.5 - 2 in the north, and 2-3 Downeast. Currently, looking at maybe 0.5-1 of rain, but areas with convection could produce higher totals.

Currently, models are under predicting the strength of Atlantic Bermuda High, which could impact the timing and track of the impending system. Models seem to agree that the high should weaken by the weekend, but if not, this could impact rainfall totals. Will have to monitor as CAMs pick up on low pressure system.

KEY MESSAGE 3...Scattered rain showers and thunderstorms early next week.

KEY MESSAGE 3 DESCRIPTION... Rounds of shortwaves move through the north early next week, bringing a chance for rain showers and some thunderstorms. Thunder possible in the north on Monday, and areawide Tuesday. Environment does not look too impressive for strong thunderstorms, so could just be some brief isolated storms below severe criteria.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Tonight...Mainly VFR. Another round of MVFR/IFR river valley fog. BHB likely to be impacted by fog late after midnight. Light W winds.

Friday...VFR. Cannot rule out an isolated storm at BGR in the afternoon. W winds 5kts.

Friday night...VFR early, with MVFR in showers/low cigs late. Light winds.

Saturday...MVFR/IFR in showers with possible thunderstorms in the afternoon to evening. S winds 5-10kts possible Saturday afternoon.

Saturday night-Sunday...MVFR/IFR in showers early Saturday night and again Sunday afternoon. Chance for fog early Sunday morning. W winds 5-10KT.

Sunday night-Monday...VFR at night, and MVFR possible in storms Monday. W winds, gusting to 15-20KT possible Monday.

Monday night-Tuesday...MVFR possible in showers Monday night and potential storms Tuesday afternoon. W winds at 5-10kts.

MARINE

Winds and seas below small craft levels for all waters through the weekend. Seas will generally range between 2 and 4ft throughout the period. Fog possible over the waters tonight. Chance for rain and thunderstorms Saturday evening.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Heat Advisory from 1 PM to 6 PM EDT Friday for MEZ011-015>017- 029-031. MARINE...None.