textproduct: Caribou

WHAT HAS CHANGED

- Updated aviation discussion for 12z TAFs.

- Fewer showers today than previously thought with coverage being only isolated.

- Slowed the POPs for Wednesday night & realigned the west to east progression to follow global model trends.

KEY MESSAGES

1) Several mostly dry days in a row from Monday to Wednesday, with the potential for frost Monday night and Tuesday night.

2) Another unsettled stretch with a soaking rainfall expected Wednesday night into Friday AM especially from the Central Highlands to Downeast coast to help continue improving drought conditions.

DISCUSSION

KEY MESSAGE 1...Several mostly dry days in a row from Monday to Wednesday, with the potential for frost Monday night and Tuesday night.

KEY MESSAGE 1 DESCRIPTION... We are finally getting three dry days in a row, outside of isolated showers this afternoon. This will be longest dry stretch we've had in about two weeks, as the weather pattern has been quite active and wet. Instability is not looking as good this afternoon previously though, so we have decreased the shower chance to around 20 percent for most areas. Although we can't 100 percent rule out a shower Tuesday, the overwhelming majority of the area will be dry Tuesday into Wednesday. There will be some daytime cumulus both Monday and Tuesday with partly to mostly cloudy skies.

We are also watching for potential frost Monday night and Tuesday night. The airmass over the region is fairly cool for this time of the year. High pressure will still be moving in Monday night, while it will be centered over the area Tuesday night. Feel that Tuesday night is the better frost risk, but the risk is still there for Monday night, mainly in the north, depending on how much clouds persist and the degree of decoupling. More confidence in the decoupling Tuesday night, with temperatures generally 2-6F cooler Tuesday night than Monday night.

The frost/freeze program begins today for zones 15-17 (Bangor Region, Northern Hancock and Central Washington) and zones 29-30 (coastal Downeast Maine). So, while frost may occur further north, the climatological growing season has not begun yet there, so impacts there will not be discussed. Tuesday night into Wednesday AM has a higher probability of needing frost headlines in these active growing season zones.

KEY MESSAGE 2...Another unsettled stretch with a soaking rainfall expected Wednesday night into Friday AM especially from the Central Highlands to Downeast coast to help continue improving drought conditions.

KEY MESSAGE 2 DESCRIPTION... Wednesday night the 500mb ridge overhead shifts east into the Maritimes as a mostly vertically stacked system tracks from the Eastern Great Lakes into Western New England. A mid level warm front lifts northeast over the area increasing PWATs to 130-150 percent of normal allowing for light rain to develop from SW to NE, with far Downeast areas being last to see the rain. Rain is likely across the area and is a complete washout on the day Thursday with a good soaking rainfall. Model uncertainty exists Thursday night into Friday as the 500mb low tracks south of the state and slows significantly down with North Atlantic blocking. The rain will taper to widespread showers into Friday with continued unsettled weather into next weekend. Probabilities for 1 inch or greater of rainfall have significantly increased over the last 3 cycles of global models in the Wed Night - Fri timeframe. Looking at 50-70 percent now for the Central Highlands, Bangor Region and into the Downeast. These areas currently have D0-D2 drought conditions with the worst D1-D2 in Southern Penobscot and Southern Piscataquis counties. Moderate-High probabilities of 1 inch or greater rainfall is a great sign as green up is underway in these locations which naturally taxes the groundwater system. Additionally, no flooding is expected but the current normal to above normal streamflows will likely rise into much higher percentiles for this time of year. Those planning to head out for activities along area rivers and streams should expect much faster higher/faster flows.

AVIATION /09Z MONDAY THROUGH FRIDAY/

Today... VFR areawide, except LIFR before 14z near the coast east of BHB. Also can't rule out very brief MVFR with any isolated showers. SCT-BKN deck around 6000 ft AGL developing 14-16z. W/NW wind increasing to around 10 kts.

Tonight... VFR areawide with light winds.

Tuesday... VFR areawide with NW wind 5-10 kts.

Wednesday - Wednesday night...VFR during the day. MVFR overnight as -RA begin to move in, south to north. W/SW winds 5-15kt. Shift S/SE overnight.

Thursday-Thursday night...MVFR/IFR likely with -RA. S/SE winds 10 to 15 kts today becoming E/NE around 5 kts overnight

Friday...MVFR/VFR with numerous rain showers. N wind 5 to 10 kts.

MARINE

Small craft seas around 5 ft persist today, then decrease below 5 ft tonight and Tuesday. Winds easily below small craft levels through Tuesday. Below SCA conditions through Wednesday. SCA conditions for winds/seas on the coastal waters possible Wednesday night into early Thursday night and on the intracoastal waters into Thursday. Will need to monitor the trend of the storm system south of the waters for potential prolonged swells >5ft into next weekend. The outer waters 25 to 60nm will likely see gusts up to 30kt Wed night into Thu Eve but SCAs for wind/waves are not issued there by policy.

Sea surface water temperatures are ranging from 40-44F from the Downeast coast out 60nm and east to the Hague Line, including Penobscot and Passamaquoddy Bays.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ050- 051.