textproduct: Caribou

WHAT HAS CHANGED

- Slowed the progression of rain Sunday night and Monday.

KEY MESSAGES

1) A chance for patches to areas of frost across portions of Aroostook County late tonight. This may lead to damage to sensitive vegetation.

2) Widespread soaking rain from Sunday night into Memorial Day. This could help aid in mitigating on going drought conditions across portions of the region.

3) Continued unsettled weather through the week with multiple systems coming into the area.

DISCUSSION

KEY MESSAGE 1... A chance for patches to areas of frost across portions of Aroostook County late tonight. This may lead to damage to sensitive vegetation.

KEY MESSAGE 1 DESCRIPTION... Deep layered ridging continues to build over the area tonight, as surface high pressure slides offshore allowing a light return flow over the area. The main question is how quickly opaque cirrus builds into Aroostook County overnight. NBM appears to fast in bringing in opaque high clouds, so have slowed progression more in line with NAM. As a result lowered lows with NBM/NBM10/ConsMOS blend, with main change across Aroostook County. Even with that, case for more than patchy frost is marginal. Therefore will not be issuing any frost headlines for tonight with the early morning forecast issuance.

KEY MESSAGE 2... Widespread soaking rain from Sunday night into Memorial Day. This could help aid in mitigating on going drought conditions across portions of the region.

KEY MESSAGE 2 DESCRIPTION... The exiting of the deep layered ridge axis to the east late Sunday, allows for strong low level warm advection to set up Sunday night and to continue into Memorial Day. At the surface, high pressure slowly exits to the east, with a cold air damming signature over the region, that is reinforced by a surface low tracking across the Gulf of Maine on Memorial Day.

Model trends have shown a later start for the rain moving from W to E. In addition, model trends show the shortwave slowing down on Monday. Thus, rain develops late Sunday night and ends Monday evening.

This system should bring widespread wetting rain to the region with the potential for up to 0.75 inch of rainfall along the coast. Around 0.25 inches for the rest of the area. The rainfall coupled with the cold air damming should result in Monday being cooler than Sunday, with highs mainly in the mid to upper 50s.

KEY MESSAGE 3... Continued unsettled weather through the week with multiple systems coming into the area.

KEY MESSAGE 3 DESCRIPTION... Per previous discussion: A strong upper level ridge over the center of the country will throw multiple shortwaves into our area over the next week. The ridge will reach all the way into northern Canada, while our area will be on the trough side of this pattern. This will bring multiple rounds of rain through the week. Models differ on the exact timing of each of these rounds, which will depend on the strength and position of this pattern.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

Today...VFR. NW winds 5-10kts at northern terminals. At southern terminals, a seabreeze of around 10KT develops by mid- late afternoon. Winds become light and variable again at all locations late this afternoon/early this evening.

Late tonight-Sunday...VFR, except for a very low chance of MVFR at KBHB/KBGR late Sunday afternoon.

Sunday night...IFR or lower conditions likely develop by late Sunday night as rain moves in. Fog possible at southern terminals. LLWS possible. SSE winds 5-10 kts gusting to 20 kt.

Monday...MVFR/IFR due to rain. Winds SE at 5-10 kt becoming light and variable in the afternoon.

Monday night-Tuesday...VFR, except for a brief period of MVFR possible Tuesday afternoon in any stronger showers at northern terminals . W winds 5-10 kts.

Tuesday night-Wednesday...MVFR as rain spreads into BGR/BHB. Light S winds Tue night, then NW winds 5-10 kts Wed.

MARINE

A light pressure gradient over the waters through Sunday will limit the sustained winds to 10 kt or less and the seas to 2 ft or less over all waters. There is a chance for gusts to around 20 kt over the outer waters Sunday afternoon.

SCA conditions are possible over the coastal ocean waters Sunday night into Monday night, with sub-SCA conditions over the intra-coastal waters. On the outer waters Sunday night and Monday, there should be wind gusts up to 25-30KT and seas up to 8 ft. While winds subside Monday night on the outer waters, seas could remain up to 6 ft. A relaxed pressure gradient returns to the waters on Tuesday, with winds 15 kt or less and seas 4 ft or less on the coastal ocean waters and 5 ft or less on the outer waters. Winds and waves remain below SCA conditions Wednesday.

Sea surface temperatures remain in the middle 40s and are conducive to hypothermia to anyone immersed in the waters.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Beach Hazards Statement through this evening for MEZ029-030. MARINE...None.