textproduct: Caribou

WHAT HAS CHANGED

- Low thunderstorm chances for this evening.

- Increased fog coverage for tonight, especially for Downeast.

- Raised precipitation chances Sunday to around 80 percent for central and Interior Downeast areas.

KEY MESSAGES

1) Showers will taper off this evening, giving way to areas of dense fog overnight. This fog will significantly reduce visibility and result in hazardous travel conditions. After the fog dissipates tomorrow morning, expect another round of scattered showers and thunderstorms.

2) A chance of showers and storms nearly every afternoon from Sunday through Friday. However, all-day rainfalls are not expected.

3) Very warm temperatures Monday through Friday and increasingly muggy. Hazardous heat is possible Wednesday through Friday.

DISCUSSION

KEY MESSAGE 1...Showers will taper off this evening, giving way to areas of dense fog overnight. This fog will significantly reduce visibility and result in hazardous travel conditions. After the fog dissipates tomorrow morning, expect another round of scattered showers and thunderstorms.

KEY MESSAGE 1 DESCRIPTION... A 500mb upper level shortwave pivots into New Brunswick this evening bringing an end to showers. Cannot rule out a few isolated thunderstorms before sunset across the Moosehead Region to Bangor Region. Showers taper off by midnight with significant moisture remaining in the lowest part of the boundary layer. As winds go calm tonight and the temperatures cool to the elevated dew point expecting areas of fog to develop. After midnight that fog may become dense to a quarter mile or less. Will message that travel will be hazardous in areas that see the low visibilities tonight. Will monitor the trend this evening for a potential Dense Fog Advisory. Fog will lift with the sun angle increasing tomorrow and clouds gradually lift leading to breaks in the afternoon. The 500mb low near James Bay will continue to pivot weak shortwave energy over the area. As daytime heating occurs expect some bubble up cu that will lead to scattered showers and a few thunderstorms. Best chance of storms will be across the Moosehead Region to Baxter Region that may impact outdoor activities. It will be warmer tomorrow with more sunshine in the low to mid 70s.

KEY MESSAGE 2...A chance of showers and storms nearly every afternoon from Sunday through Friday. However, all-day rainfalls are not expected.

KEY MESSAGE 2 DESCRIPTION... Shower and thunderstorm Sunday afternoon looks fairly numerous, especially for central/southern portions of the area. We will be under NW flow aloft, with a weak system moving through which should help spark thunderstorm development. Shear and instability is enough that a few storms could be on the stronger side. Didn't include any enhanced word such as hail or wind gusts into the forecast for now, but it's something to watch. CAMs do differ some on how much instability there will be.

Monday looks a bit quieter for convection, with probably just an isolated shower Downeast. However, as airmass moistens from Tuesday on, the chance of afternoon showers/storms increases. Also, the center of the upper level ridge axis will remain to our west and we will be under fairly unstable NW flow aloft, and with very warm temperatures and a muggy airmass, this is a very good pattern for severe weather at some point Tuesday to Friday. Hard to tell which day will have the best chance for severe storms, but this is definitely a pattern to watch out for.

KEY MESSAGE 3...Very warm temperatures Monday through Friday and increasingly muggy. Hazardous heat is possible Wednesday through Friday.

KEY MESSAGE 3 DESCRIPTION... In addition to the afternoon showers and storms, the heat is another thing to watch out for. There is still some uncertainty just how warm it will get, but at the least we will be looking at low to mid 80s for highs and upper 50s to mid 60s for low. The greatest risk for the warmest temperatures is Wednesday through Friday, as on Monday and Tuesday the heat will still be building. Can't rule out some places getting up to around 90 degrees Wednesday to Friday. In addition, it will be quite muggy and if we get air temperatures up close to 90, heat indices will likely begin to reach heat advisory criteria which is 95. Right now, for each day Wednesday through Friday, the chance of reaching heat advisory criteria (95 heat index) is 10-20 percent, highest in the area from Bangor to Dover-Foxcroft. The chance of reaching heat advisory at any point Wednesday to Friday is 25-50 percent. In addition, nighttime low temperatures will be quite mild and those without air conditioning will really start feeling the effects later in the week.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

Tonight...Aroostook County Terms MVFR/IFR cigs. Areas of IFR FG. Winds becoming light and variable to near calm.

KBGR...Deteriorating to IFR after 03z with cigs dropping to 500 feet and vsby down to 2SM in BR by 6z. TEMPO 07-11z for LIFR FG. Winds variable around 5 kt or less. At KBHB IFR/LIFR cigs with vsby dropping to 1SM. TEMPO for FG 07-11z that may be down to 1/4mi. Winds light and variable.

Tomorrow...Aroostook County Terminals IFR/MVFR conditions in AM due to FG/BR improving to widespread MVFR by 12z. Conditions improve to VFR after 15z to 17z with cigs lifting. Winds light and variable. KBGR AM low cigs and BR improving to MVFR by 13z. VFR conditions expected after 17z. Winds light and variable. At KBHB LIFR/IFR conditions due to FG improving to MVFR after 13z as cigs lift. VFR expected by late morning to early afternoon. Winds light and variable.

Saturday night-Wednesday: Areas of MVFR/IFR in the overnight and early morning hours from fog. Best chance of overnight and early morning MVFR/IFR is closer to the coast, but the possibility will exist anywhere. Generally VFR midday to evening hours except for in heavy showers, with the potential for thunderstorms. There will be a chance of afternoon showers and storms every day except Monday. Winds will be less than 10 kts.

MARINE

Through midweek, expecting winds less than 15kt over the waters 25-60nm and seas 2-3ft. Winds/seas below SCA conditions on the Intra-Coastal and Coastal Waters. Fog will reduce vsby less than 1nm at times through midweek on all the waters.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...None.