textproduct: Caribou

WHAT HAS CHANGED

- 8:00PM UPDATE...Cold front continues to work across the CWA with the front passing over Bangor noted by the FAA webcams. Last few images of GOES-E shows the front very nicely. The front is pushing through eastern Aroostook County now. Remaining lightning activity is across far Eastern Aroostook and moving into New Brunswick. Severe threat has ended across the CWA. Fog remains across Bar Harbor and coastal Washington county and this will break/lift as the cold front crosses. Aviation section update below. - Additionally, have allowed the High Surf Advisory to expire at 8PM. Have extended the Small Craft Advisory on the Intra- Coastal Waters till 11AM Thursday and Coastal Waters out to 25nm till 8PM Thursday. Seas 4-7ft on the Intra-Coastal Waters and 5-8ft on the Coastal Waters.

KEY MESSAGES

1) Isolated severe thunderstorms are possible through the remainder of the afternoon into the evening, mostly across northern/central portions of the forecast area. Locally heavy rainfall is possible which could lead to minor urban flooding.

2) Dangerous rip currents and high surf along the Downeast coast into this evening.

3) Potential for a system moving in early next week, bringing another round of wetting rainfall.

DISCUSSION

KEY MESSAGE 1...Isolated severe thunderstorms are possible through the remainder of the afternoon into the evening, mostly across northern/central portions of the forecast area. Locally heavy rainfall is possible which could lead to minor urban flooding.

KEY MESSAGE 1 DESCRIPTION... A Slight Risk of severe thunderstorms across northern/central portions of the forecast area this afternoon and evening, with a Marginal Risk across Downeast areas. Thunderstorms have developed in advance of a cold front currently approaching western portions of the forecast area. A strong mid/upper level jet is helping provide support for the thunderstorms. Additional support is being provided from a disturbance in advance of an approaching upper trof. The strength of afternoon thunderstorms will largely depend on the amount of heating and de-stabilization which occurs with greater sun leading to increased instability. CAPE values of 1000-1500 J/kg, with Downdraft CAPE values of 1000-1500 J/KG are expected in advance of the cold front. Strong to possibly severe thunderstorms will persist through the afternoon into the evening in advance of the cold front, ending in the wake of the front. Strong/damaging wind gusts will be the primary threat with the stronger storms, though large hail could also occur with the more organized storms. In addition, heavy downpours could accompany any thunderstorms. This could lead to localized urban/poor-drainage flooding.

KEY MESSAGE 2...Dangerous rip currents and high surf along the Downeast coast into this evening.

KEY MESSAGE 2 DESCRIPTION... A High Surf Advisory remains in effect through 8 PM. Unusually rough seas by late July standards are expected to peak today. This is usually the quietest time of year on the waters, but seas in the neighborhood of 6-9 feet are expected up to the coastline, with a 9- 10 second period swell from the south. People along the coast should exercise caution if recreating. Water temperatures in the 50s.

KEY MESSAGE 3...Potential for a system moving in early next week, bringing another round of wetting rainfall.

KEY MESSAGE 3 DESCRIPTION... A ridge of high pressure will cross the forecast area this weekend, and during this time temperatures could build to slightly above seasonal averages with highs in the low to mid 80s. By Monday next week, another shortwave may approach from the west, bringing the next round of moisture into the area that could bring a chance of showers/thunderstorms. A more organized system is possible Tuesday into Wednesday though details are still uncertain.

AVIATION /00Z THURSDAY THROUGH MONDAY/

00z TAF UPDATE...

Tonight...remaining -SHRA/VCTS ending soon with conditions becoming VFR. Low end VFR north. LIFR at BHB for a few more hours till FROPA. Then improving. BCFG/BR possible all terms late tonight into early AM. Southwest/west winds 10 to 15 knots becoming 5-15kt.

Thursday...Variable conditions with any patchy fog early. Otherwise, VFR/MVFR early then VFR. Isolated afternoon showers possible north. West winds 10 to 15 knots with gusts up to around 20 knots.

Thursday night...Variable conditions with any patchy fog late. Otherwise, VFR. West/southwest winds 5 to 10 knots.

Friday through Monday...Variable conditions in any patchy late night fog. Otherwise, generally VFR. Southwest/west winds 10 to 15 knots Friday. Variable winds 5 to 10 knots Friday night. South/southwest winds 5 to 10 knots Saturday through Monday.

MARINE

Small Craft Advisory conditions persist for the intra-coastal and coastal waters through tonight, which will likely need extending into Thursday. Isolated showers/thunderstorms this evening. Patchy fog through early morning. Winds and seas decrease below small craft advisory conditions across all waters Friday through the weekend.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 8 PM EDT Thursday for ANZ050-051. Small Craft Advisory until 11 AM EDT Thursday for ANZ052.