textproduct: Caribou

WHAT HAS CHANGED

- Confidence is increasing in significant rainfall Thursday and Friday.

KEY MESSAGES

1) Warmer and dry conditions continue through Tuesday, winds increase on Tuesday for a fire weather concerns.

2) Significant rainfall is possible Thursday into Friday, which should be beneficial for the ongoing groundwater drought.

DISCUSSION

KEY MESSAGE 1...Warmer and dry conditions continue through Tuesday, winds increase on Tuesday for a fire weather concerns.

KEY MESSAGE 1 DESCRIPTION... Warm temperatures are expected again on Tuesday as the 500mb ridge axis just west of the area shifts overhead. 850mb temperatures around 3 to 5C will yield surface temperatures well into the 60s to near 70F. Winds shift south on Tuesday leading to more marine induced cooling across Downeast Maine where some locations closer to the coast may struggle to get out of the 50s despite ample sunshine. South winds around 10 to 15 mph, combined with decreasing relative humidity in the 20 to 30 percent range and recent dry weather, could lead to fire danger concerns. If considering burning please consult the Maine Forest Service website or listen to NOAA Weather Radio where fire danger ratings are broadcast each morning.

KEY MESSAGE 2...Significant rainfall is possible Thursday into Friday, which should be beneficial for the ongoing groundwater drought.

KEY MESSAGE 2 DESCRIPTION... High confidence in a cooler, wetter weather pattern setting up beginning Wednesday. Potential rain on Wednesday looks fairly minor, likely a quarter inch or less and limited mostly to areas south of Millinocket. The more widespread, heavier rain appears to arrive Thursday afternoon in western portions of the area, and Thursday night/Friday everywhere. The rain will be ahead of a relatively strong, and strengthening, surface low pressure system approaching from the southwest. This surface low moves through either Downeast Maine or the Northern Gulf on Friday, then into New Brunswick Friday night. There is still some uncertainty on the timing of the start/end of the rainfall. For example, far eastern Maine could stay dry all day Thursday or could be wet. Also, the rain could linger into Saturday or taper off Friday afternoon. Too early to say for both. Bottom line is some pretty healthy rain totals through this whole period. The chances of total rain exceeding one inch are around 40 percent in the north and 80 percent Downeast. The chance of exceeding two inches is around 10 percent in the north and around 40 percent Downeast. We don't anticipate the rain to be enough for anything other than very minor nuisance flooding, and if any of this occurs, it would most likely be over southern portions of the area. There will be a decent breeze from the east/southeast as the low pressure approaches, peaking late Thursday into Friday. Gusts 20-30 mph over land are possible, with gusts 30-40 mph over water. This likely won't be enough for any impacts to trees. Temperatures during the rain will be seasonably cool and generally in the 40s to low 50s. We can't rule out a secondary low pressure system for Sunday/Sunday night bringing more rain, but confidence in this is low. There's about a 30 percent chance of at least another quarter inch of rain in the Sunday/Sunday night period. In this wetter, cooler pattern, fog could be an issue from time to time, especially Downeast.

AVIATION /18Z MONDAY THROUGH SATURDAY/

Rest of Today...FEW-SCT VFR with high cigs north and mid level cigs south. Light and variable winds except S-SE at BHB and BGR due to seabreeze 5-10kt.

Tonight...High VFR or SKC. Light and variable winds.

Tuesday...FEW-SCT high cig VFR. S-SE winds 5-15kt gusting up to 20kt at times possible.

Wednesday: MVFR north and IFR south. Possible -RA. SE wind 5-10 kts.

Wednesday night: IFR south and MVFR/IFR north. Possible -RA. SE wind 5-10 kts.

Thursday: IFR south and MVFR/IFR north. RA developing. ESE wind 10-15 kts. LLWS possible.

Thursday night: Likely IFR in RA across most terminals. E winds 10-15 kt. LLWS possible.

Friday: MVFR/IFR in rain. Some uncertainty in how quickly rain moves out which will determine how long IFR conditions hold on. E wind 10-15 kt.

Friday Night and Saturday: Variable wind around 10 mph become W on Saturday. IFR/MVFR generally improving to MVFR/VFR, but low confidence.

MARINE

Winds around 10 kts or less are expected through Tuesday with seas gradually building to 2 to 4 feet beyond 10NM offshore as a SE swell develops with a period of 7 to 8 seconds. Sea surface water temperatures range from 38-42F from the Downeast coast out 60NM and east to the Hague Line including Penobscot and Passamaquoddy Bays.

Seas increase to small craft conditions Tuesday night and winds increase to above SCA criteria by Thursday morning on the coastal waters. A 30% chance of gales over the coastal and outer waters late Thursday through Friday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...None.