textproduct: Caribou

WHAT HAS CHANGED

- Added gusty winds enhanced wording to the thunderstorms across the St. John Valley and far Northern Aroostook County this late afternoon and early evening to be in line with the Storm Prediction Center D1 outlook.

- Rain chances have increased for Friday night and Saturday, especially for the Bangor region and Downeast.

KEY MESSAGES

1) Showers with possible thunderstorms late this afternoon and early this evening over Northern Maine may bring gusty winds, brief heavy rainfall and cloud to ground lightning.

2) Below normal temperatures are expected from Thursday through early next week.

DISCUSSION

KEY MESSAGE 1...Showers with possible thunderstorms late this afternoon and early this evening over Northern Maine may bring gusty winds, brief heavy rainfall and cloud to ground lightning.

KEY MESSAGE 1 DESCRIPTION... Instability increases ahead of the low pressure, enough for the risk of some storms in the far north/northwest late afternoon. One problem is that the system arrives just a bit late to tap into the maximum daytime heating. The best dynamics occur near or just after sunset. This means that while there may be some storms in the north, most likely they will not be severe as we will be losing our daytime heating as the bulk of the shower/storm activity moves through Northern Maine. Cannot rule out a couple hours around sunset with some storms getting some gusty winds. LLJ is increasing to 40-50kt and shear begins to peak. This low CAPE and high shear environment may produce some a little more robust storms. Hi-Res CAMs showing helicity >100 m2s2 which suggest some stronger updrafts possible. However, due to the timing with sunset not expecting widespread severe. The latest D1 Storm Prediction Center outlook does have Northern Maine in a Marginal for severe weather. Good confidence that the far north will get some decent rain totals this evening, with some places from Caribou north topping one half inch to three quarters of an inch. Further south, little if any rain is expected this evening, as the low pressure center and best upper level dynamics will be tracking from NW to SE over far Northern Maine.

KEY MESSAGE 2...Below normal temperatures are expected from Thursday through early next week.

KEY MESSAGE 2 DESCRIPTION... An upper level trough is expected to dominate across northern New England through early next week. This will result in unseasonably cool high temperatures from Thursday right through the upcoming weekend, and into early next week. Along with the cooler temperatures will come the chance for showers Thursday through Friday. There is even the chance for some higher elevation snow showers.

An area of upper level low pressure is expected to dive southward from Quebec Province during Friday and then across New England Friday night through Saturday. This system is expected to pass to the southwest of the region. There is some guidance and ensemble data that brings to the rainfall associated this feature farther east into the forecast area. Thus, there is now a higher likelihood of some rain moving into the region, especially for the Bangor and Downeast region. Some guidance is indicating the potential for over an inch of rain for some portions of the area Friday night through Saturday.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Rest of this afternoon...VFR conditions. SHRA approach from the NW at FVE, CAR, PQI and HUL. PROB30s added to those sites for potential TSRA lowering cigs/vsby this evening. Winds light and variable until the showers/storms arrive.

Tonight...FVE, CAR, PQI and HUL will see BR/FG develop overnight with SHRAs becoming VCSH. Overall VFR becoming MVFR/IFR cigs. TEMPO groups added for vsby/cig reductions with FG. Confidence is low-moderate at most of the sites because it will heavily depend on rain occurring. BGR and BHB will be VFR tonight. LLWS this evening at all sites except BHB and BGR LLWS expected much of the night.

Wednesday...Aroostook terms IFR/MVFR becoming MVFR then VFR by afternoon due to cigs. VCSH/-SHRA possible at those sites. BGR and BHB will be VFR. NW winds 5-15kt and gusting up to 20kt.

Thursday through Friday...Mainly VFR BGR/BHB and MVFR or VFR HUL/PQI/CAR/FVE. Showers possible. N wind 5 to 15 kts with higher gusts during the day.

Friday night through Saturday...MVFR or lower is possible in rain, especially BGR/BHB.

Sunday...VFR/MVFR. Sct showers.

MARINE

Winds/seas below SCA on the Intra-Coastal Waters through Wednesday night. Small Craft Advisory has been extended until 5AM EDT for the Coastal Waters out 25nm. SW winds 10-20kt with gusts up to 25kt and seas 4-6ft. SW winds gusting up to 25kt on the Waters 25-60nm offshore tonight will become W and drop to less than 15kt on Wednesday. All waters will see seas subside to 2-4ft by Wednesday.

Winds/seas are expected to be below SCA levels Thursday and Friday. Winds and seas could approach SCA levels Saturday and Saturday night.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 5 AM EDT Wednesday for ANZ050-051.