textproduct: Caribou

WHAT HAS CHANGED

- Updated aviation discussion. - Beach Hazards Statement allowed to expire.

KEY MESSAGES

1) Mild, mainly dry and breezy conditions into Monday may lead to some fire weather concerns.

2) Thunderstorms and very warm temperatures possible Tuesday and Wednesday.

DISCUSSION

KEY MESSAGE 1...Mild, mainly dry and breezy conditions into Monday may lead to some fire weather concerns.

KEY MESSAGE 1 DESCRIPTION... High pressure well southeast of the Gulf of Maine allows for a a weak shortwave and cold front to cross the region tonight with isolated to scattered rain showers. Much of the region will remain dry but cannot rule out up to a tenth of an inch across the North Woods and St. John Valley. Temperatures tonight remain mild in the low to mid 50s. Sunday will feature high pressure building down from Ontario/Quebec as the flow turns NW across the area. This will result in the warmest temperatures downslope of the Longfellow Mtns and traditionally leads to much lower dew points. Green up is occurring across the CWA with 60-70 percent green up in the Downeast with 20-40 percent green up in Northern Maine. Factoring this in still expecting lower than guidance dew points in much of the area and opted to mix dew points closer to the NBM 25th percentile. This will result in afternoon relative humidities down to 30-37 percent across much of the area except the upslope areas of Moosehead and into Northern Somerset/Piscataquis counties (40-47 percent).

Tomorrow, hi-res soundings showing a well mixed boundary layer up to 850mb to 825mb, noticeable inverted V signature with increasing winds aloft that will be tapped into. Expect wind gusts 20-30mph with isolated gusts up to 35mph. Combination of dry fine fuels, gusty winds and low RHs may result in some fire weather concerns. Partly to mostly sunny skies and temperatures in the low to mid 60s in the North Woods, Moosehead Region...Upper 60s for the rest of Northern Maine with low to mid 70s for the Bangor Region, Upper Penobscot Valley to Downeast Coast.

Dry conditions into Sunday night will lead to some areas of frost especially across Northern Maine. The frost/freeze program is not active in these areas so do not expect headlines.

Inverted V is not quite as pronounced in soundings Monday as it was on Sunday. Did lower dewpoints, especially across the North, by blending in CONSMOS with the NBM. Still looks afternoon minimum RHs in the 20s across most of the area, except for around 30 across southern portions of the Central Highlands, the Bangor Region and coastal Downeast Maine. Wind gusts should peak around 10 mph across the North, but could be in the lower 20 mph across the Bangor region. So the fire concerns seem reduced on Monday when compared to Sunday.

KEY MESSAGE 2...Thunderstorms and very warm temperatures possible Tuesday and Wednesday.

KEY MESSAGE 2 DESCRIPTION... Deep layered ridging crosses the area Tuesday and Tuesday night, followed by southwest flow aloft on Wednesday with shortwaves embedded in the flow impacting the area. At the surface, the models have trended northward with the frontal boundary, now suggesting it could stall out across northern Maine, if not just north of the border Tuesday and Tuesday night, then a cold front approaches on Wednesday, possibly reaching far western Maine by late Wednesday afternoon.

Based on this, only have slight chance pops across Downeast Maine on Tuesday and limit likely pops to North of Bangor. Do have a swath of categorical pops across most of Northern Maine,except near the northern border with Canada, where restrict to likely due to uncertainty in the frontal placement.

With 1000-2000 J/kg of CAPE, highest from the Central Highlands into S Aroostook, do have slight chance/chance of thunder as well. The CAPE coupled with 30-40KT of bulk shear should allow for strong to possibly severe storms across most of Northern and Central Maine Tuesday afternoon. With the main threat strong gusty winds and large hail. The high res NAM and CMC-Reg both show bullseyes of 1-1.5" of rainfall potentially tracking across the southern tier of N Aroostook County late Tuesday afternoon/early Tuesday evening. So did bump up NBM pops with CONSRaw. It should be noted that the QPF is basin average and is not meant to capture isolated bullseye's like that suggested by the CMC-Reg and NAM. The QPF bullseye does suggest the potential for locally heavy rainfall with any stronger convection, which could result in the ponding of water on roadways with the resulting chance of hydroplaning.

For highs on Tuesday, blended in CONSMOS with the NBM to temper highs a bit, given the high bias to NBM highs in the current pattern.

Thunderstorms could linger into Tuesday evening, especially across portions of the North, before tapering off overnight.

Another round of showers and thunderstorms is likely ahead of the cold front on Wednesday. With better surface forcing, the region in the right rear quadrant of a 140+ kt upper jet, 40-50 kt of bulk shear, along with 500-1000 J/kg of CAPE, could once again see another round of strong to possibly severe thunderstorms ahead of the front. The main threat would be from strong gusty winds. Once again, there is the threat for locally heavy rainfall, with more ponding of water on roadways and the resultant potential for hydroplaning. Also, if locally heavy rainfall on Wednesday occurs over a location that received locally heavy rainfall on Tuesday, minor flooding in that area cannot be completely ruled out.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Tonight...Occasional MVFR possible late north. Otherwise, VFR. Isolated/scattered showers. South/southwest winds 5 to 10 knots, becoming southwest/west 10 to 15 knots. Westerly low level wind shear.

Sunday...VFR. West/northwest winds 10 to 15 knots with gusts up to 25 to 30 knots.

Sunday Night-Monday: VFR. SW winds G15-20KT possible Monday afternoon.

Monday night: VFR with a very small chance of a brief period of MVFR in any convection at KFVE. LLWS possible.

Tuesday/Tuesday evening: MVFR or lower possible in any stronger thunderstorm, with the best chance in the afternoon/early evening at KCAR/KPQI/KHUL. WSW winds G15-20KT possible Tuesday afternoon.

Late Tuesday night: MVFR or lower possible.

Wednesday: MVFR or lower possible in any stronger thunderstorm. WSW winds G15-20KT possible; becoming NW in the afternoon.

Wednesday night-Thursday: VFR. NW winds G15-20KT possible.

MARINE

Small Craft Advisory remains in effect til 8AM Sunday for the Coastal Waters out to 25nm. SW winds 15-20kt with gusts up to 30kt and seas 4-7ft. Winds/seas below SCA on the Intra-Coastal Waters. Winds are gusting up to 30kt across the 25-60nm waters tonight into Sunday, expecting to remain below Gales with seas 6-8ft. Tomorrow as winds shift W expecting winds/seas to fall below SCA conditions on the Coastal Waters but cannot rule out a need to extend the out to 25nm waters due to waves. Will need to monitor the trends. Intra-coastal waters 2-4ft seas and 4-5ft seas for the rest of the waters except 5-6ft over the outer most 25-60nm waters.

Sub-SCA conditions are forecast on the intra-coastal waters Monday-Thursday. The coastal ocean waters should see sub-SCA conditions Monday and Monday night, then have SCA conditions possible from Tuesday into Wednesday night. Sub-SCA conditions should then return there on Thursday. For the outer waters, winds should be below 25 kt and seas 5 ft or less Monday and Monday night. From Tuesday through Wednesday night, the outer waters could see gusts of 25-30KT and seas up to 6 ft. Thursday should see a return to winds under 25 kt and seas of 5 ft or less to the outer waters.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 8 AM EDT Sunday for ANZ050-051.