textproduct: Caribou

WHAT HAS CHANGED

- 8 AM Update to Aviation section with issuance of 12z TAFs

- Reduced shower/storm chances during the day Saturday.

KEY MESSAGES

1) Hot and muggy Friday. Heat Advisory criteria is expected to be met in the Bangor/Penobscot Region, southern Central Highlands, and portions of Downeast Maine.

2) Scattered showers and thunderstorms through the weekend. A few severe storms are possible, with the best chance being Sunday. Very heavy downpours with any storms could lead to localized flooding.

3) Scattered rain showers and thunderstorms early next week.

DISCUSSION

KEY MESSAGE 1...Hot and muggy Friday. Heat Advisory criteria is expected to be met in the Bangor/Penobscot Region, southern Central Highlands, and portions of Downeast Maine.

KEY MESSAGE 1 DESCRIPTION... Hot and muggy today with highs climbing near to possibly above 90. Dewpoints will also climb to around 70 south and east of State Route 6, with these dewpoints being a few degrees higher than yesterday. This will produce heat indices or feels like temperatures in the mid 90s for several hours. 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 to Ellsworth. The record high temp at Caribou on Friday is in jeopardy with a forecast temp of 89. The record is 89 degrees from 2022. Millinocket could also threaten a daily record, with 91 forecast and the record being 92 in 2022.

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, but it is very likely neither Saturday nor Sunday will be as warm as Friday.

KEY MESSAGE 2...Scattered showers and thunderstorms through the weekend. A few severe storms are possible, with the best chance being Sunday. Very heavy downpours with any storms could lead to localized flooding.

KEY MESSAGE 2 DESCRIPTION... Juicy airmass will be in place today through Sunday with plenty of moisture and potential instabilty/CAPE. However, finding the trigger to initiate the storms will be a bit tricky. Also, wind shear is generally quite weak. The most likely trigger comes Sunday afternoon with a weak cold front and subtle shortwave trough. Sunday also looks like our best shot at a severe storm or two of the next few days.

First off, for today (Friday), we could see isolated to potentially scattered storms primarily over interior Downeast and into the Bangor region. It's also possible no storms form at all, and confidence is low. If any storms do form, they will be slow-moving and could produce a quick inch or two of rain. Don't anticipate any severe storms today.

For Saturday, models have generally trended less for shower coverage, and adjusted forecast accordingly. Do still have a chance of showers/storms in the forecast, with the potential existing for really anywhere except the immediate coast. However, the timing of a subtle shortwave is a bit too fast to maximize the daytime heating, with our area generally being on the back side/stable side of the shortwave by midday. This is likely the reason a lot of models backed off on shower/storm coverage. That said, if any storms do form, they could be very generous rain producers, and could be locally strong to possibly severe.

Sunday overall looks like the best day for showers/storms thanks to a weak cold front and upper level shortwave trough approaching, with a small potential of a few severe storms. The higher risk appears to be in the north and in the afternoon. Localized flash flooding is possible with any storms, as the airmass remains extremely moist.

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 /12Z FRIDAY THROUGH TUESDAY/

Today: High confidence in VFR through the TAF period at KFVE/KCAR/KPQI/KHUL/KBHB. High confidence in VFR at KBGR, except for low (20-30 percent) chance of MVFR or lower in any isolated to scattered thunderstorms midday to early afternoon. Light winds except S 10 kts at BHB after 17z.

Friday Night: Mainly VFR, with a 25 percent chance of MVFR, except a 40 percent chance of MVFR/IFR at BHB late night. Light winds.

Saturday: MVFR or lower possible early in the morning, then MVFR/IFR possible in any showers with possible thunderstorms in the afternoon to evening. Otherwise VFR. Light S winds.

Saturday night-Sunday: MVFR/IFR possible in showers early Saturday night and again Sunday afternoon. MVFR or lower possible in fog early Sunday morning. Otherwise VFR.

Sunday night: VFR.

Monday: MVFR possible in any storms, otherwise VFR. SW-W winds G15-20KT possible.

Monday night-Tuesday: MVFR possible in any showers Monday night and any storms Tuesday afternoon, otherwise VFR.

MARINE

Sustained winds 15 kt or less and seas 4 ft or less through Tuesday.

Fog possible over the waters through Sunday.

CAR WATCHES/WARNINGS/ADVISORIES

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