textproduct: Caribou

WHAT HAS CHANGED

- Updates to the aviation section for the 12z TAFs

- Expanded the dense fog advisory through most of the Bangor and Downeast region based on current observations and trends

KEY MESSAGES

1) Chance for afternoon showers and thunderstorms from Bangor north today. Areas of dense fog could develop again tonight, most likely in areas which receive rain from the showers and storms of the day.

2) Thunderstorms are possible Friday afternoon and evening, some of which may be strong with gusty winds and small hail.

DISCUSSION

KEY MESSAGE 1...Chance for afternoon showers and thunderstorms from Bangor north today. Areas of dense fog could develop again tonight, most likely in areas which receive rain from the showers and storms of the day.

KEY MESSAGE 1 DESCRIPTION... Unsettled weather continues through the day today as a weak front drops through the forecast area this afternoon. Combined with peak heating hours and lingering moisture, isolated to scattered showers with a few thunderstorms will be possible, and most likely across the Central Highlands up through the north... all areas which will could see the FROPA aligning with peak heating. As the boundary approaches the coast, the sun will begin to set, and a weak sea breeze could lead to a more stable marine layer Downeast, though additional storms may develop along any interaction between the weak front and the sea breeze boundary within the Interior Downeast region through the Bangor area early this evening. To support thunderstorms, CAPE seems to be forecast in good amounts, with upwards of 1000 J/kg available from various CAMs. This forecast left the NBM for forecast shower coverage, but it can be noted that the RRFS includes a solution with much more isolated shower coverage than other CAMs guidances and blends, and if the front is weaker or the area dries out more quickly than forecast, this could be the solution with far less rain.

Wherever rain falls, increased surface moisture combined with dropping temperatures behind the front could lead to the return of areas of dense fog tonight.

KEY MESSAGE 2...Thunderstorms are possible Friday afternoon and evening, some of which may be strong with gusty winds and small hail.

KEY MESSAGE 2 DESCRIPTION... A cold front crosses the area Friday on the leading edge of a full latitude trough pushing into the region, with the added support of a northern stream shortwave pushing through the trough around that time. With the potential for 500-1500 J/kg of instability and 25-35KT of bulk shear, there is a risk of some locally strong thunderstorms ahead of the front late Thursday into Friday afternoon, with the main threat expected to be strong gusty winds. The greatest chance for storms is likely to be concentrated over northern and central areas while more southern areas are likely to remain too stable due to southerly flow.

AVIATION /09Z TUESDAY THROUGH SATURDAY/

Today...IFR/LIFR may continue for another 1 to 2 hours at any terminals which remain in low cigs and FG. Quick improvement to VFR mid morning into the afternoon. MVFR or lower possible in brief rain showers and storms from KBGR northwards late this afternoon. Not confident enough to include any PROB30 for any thunder. S winds 5 to 10 kts, shifting NW late.

Tonight...VFR early, possibly becoming IFR/LIFR in fog and low clouds at any terminals which see rainfall this afternoon. Winds light and variable.

Wednesday night...VFR. Light and variable winds.

Thursday...VFR. S winds 5-15kt with gusts up to 25kt. LLWS possible late afternoon.

Thursday night...VFR, becoming MVFR/IFR with -SHRA and fog developing. S winds 5-10kt. LLWS possible.

Friday: MVFR/IFR in showers and thunderstorms. S winds 5-10kt with gusts up to 20kt possible.

Friday night: Improving to VFR. Light and variable winds.

Saturday: VFR. NW winds 5-10kt with gusts to 20kt possible.

MARINE

Winds and seas below SCA criteria through Friday. Seas 2 to 4 ft with S/SW winds. Fog likely through tonight. Thunderstorms possible Friday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Dense Fog Advisory until 9 AM EDT this morning for MEZ015>017- 029-030-032. MARINE...None.