textproduct: Caribou

WHAT HAS CHANGED

720 am...updated for 12z aviation discussion

- Added in some fog along the coast early Sunday morning, with more details in both the marine and aviation discussion as a result.

KEY MESSAGES

1) Showers and storms will return late this afternoon/evening into Sunday, with locally heavy rain possible tonight.

2) Wildfire smoke plume to our south will lift back north into Maine today leading to reduced visibility and poor air quality due to particle pollution.

3) A wetting rain likely Tuesday night through Wednesday to help with the recent dry conditions.

DISCUSSION

KEY MESSAGE 1...Showers and storms will return late this afternoon/evening into Sunday, with locally heavy rain possible tonight.

KEY MESSAGE 1 DESCRIPTION... A strengthening low pressure system over the Great Lakes will spread showers into the area by this afternoon in warm advection. As the surface low approaches northern Maine, expect rain to get heavier as a surge of moisture moves north. PWATs will approach or exceed the 90th percentile with southern areas seeing 1.50+ inches. Elevated instability may bring isolated thunder to portions of the area and this could produce locally heavy rainfall. It appears that lift associated with the low pressure across the north may be robbed of moisture with rain further to the south which will be associated with the RFQ of the upr level jet. Most areas will see between a quarter and half an inch of rainfall from this event before it moves out of the area into Sunday morning.

As the system departs, a brief surge of coastal fog is possible, though as flow quickly turns WNW that should quickly push offshore by mid-morning at the latest. At any rate, something to be mindful of early Sunday morning if you have plans to be out driving in that area.

KEY MESSAGE 2...Wildfire smoke plume to our south will lift back north into Maine later today leading to reduced visibility and poor air quality due to particle pollution.

KEY MESSAGE 2 DESCRIPTION... Large wildfires continue to burn in Ontario near the Great Lakes and additional fires in Manitoba are adding to the smoke plume. With the approaching storm system later today, a warm front lifting north will bring this smoke north into the region later this morning or early in the afternoon, especially south. Latest HRRR, RAP and RRFS smoke models shows patchy smoke reaching the Downeast coast around Noon-2PM then towards evening expecting patchy smoke across the north. Shower activity should help to dissipate the smoke before it becomes too thick, though there could be a brief period of reduced visibility and thicker smoke towards the coast before rain begins. The latest Air Quality Forecast from the Maine Department of Environmental Protection shows Unhealthy for Sensitive Groups due to particle pollution areawide today. An Air Quality Alert from Maine DEP is in effect from 10AM this morning till Midnight tonight. See the AQA for more details.

KEY MESSAGE 3...A wetting rain likely Tuesday night through Wednesday to help with the recent dry conditions.

KEY MESSAGE 3 DESCRIPTION... A seasonably strong low pressure system approaches late Tuesday from the west and passes to our north with a cold front crossing the area sometime Wednesday. A steady, wetting rain is likely with the system. Current ensemble guidance shows a 50-70% chance of at least 0.5 inches of rainfall with the storm which should help provide relief for some of recent dry conditions. 30 day precip departures are running 60-80 percent of normal in the Bangor Region, Central Highlands, Interior Downeast and across Northern Maine. Near surface soil conditions are generally below normal indicating the recent dry spell. Lastly the recent dry spell is noticeable by streamflows across the CWA in the below normal to low end normal conditions for the St. John and Penobscot basins. Across the Downeast and St. Croix basin generally in the below normal to normal conditions.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

Today...VFR through 20z north of BGR and BHB. Smoke may make it to BGR and BHB before the onset of showers, so that could reduce VSBYs below VFR for a couple of hours after 18z. VFR/MVFR mid to late afternoon with rain developing, an isolated thunderstorm possible, though confidence is too low to include a PROB30 group for -TSRA at this time. South/southwest winds 10 to 15 knots with gusts up to around 20 knots, becoming variable 5 to 10 knots. Southwesterly low level wind shear possible Downeast late afternoon.

Tonight...MVFR/IFR in locally heavy rainfall and storms. S winds 10-20kts. LLWS values around 30-40 knots at 2kft. As rain departs, some coastal fog could impact BHB and BGR prior to sunrise.

Sunday-Sunday night...Early morning fog at BHB and BGR should quickly push offshore as winds turn out of the W to NW. VFR, MVFR north in afternoon showers/storms. NW winds 10-20kts gusting to 30kts, then becoming W 5-10kts overnight.

Monday-Tuesday...Mainly VFR. W winds 5-10kts, becoming S Tuesday morning 5-15ts gusting to 25kts.

Tuesday night-Wednesday...Decreasing to MVFR early Tuesday night and possibly reaching IFR Wednesday in rain. S/SE winds 10 to 15 kts.

MARINE

Winds remain below SCA criteria with seas around 2-4 feet through this afternoon. Winds pick up out of the south later this evening and seas rise to 5-8 feet by early Sunday morning. Have issued a Small Craft Advisory from 19z Sat-18z Sun for winds and seas. Intracoastal zone may be able to be dropped Sunday morning. Gale force winds likely over the waters from 25-60NM Saturday afternoon/evening and have issued a Gale Warning for this time. Some dense fog <1 SM is possible near the overnight Saturday into Sunday morning as the rain ends.

Seas remain elevated Sunday above small craft criteria, then winds and seas below SCA criteria Sunday night through Tuesday. Winds and seas above SCA criteria Tuesday night through Wednesday with gales possible on the outer waters.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Air Quality Alert until midnight EDT tonight for MEZ001>006- 010-011-015>017-029>032. MARINE...Small Craft Advisory from 3 PM this afternoon to 2 PM EDT Sunday for ANZ050>052. Gale Warning from 4 PM this afternoon to 4 AM EDT Sunday for ANZ080-081.