textproduct: Caribou

WHAT HAS CHANGED

- Updated aviation section to reflect upcoming 12Z TAFs

- Increased confidence in timing of isolated rain showers Sunday morning

KEY MESSAGES

1) Warm and dry this weekend through early next week.

2) Scattered thunderstorms possible Tuesday and Wednesday afternoons.

DISCUSSION

KEY MESSAGE 1...Warm and dry this weekend through early next week.

KEY MESSAGE 1 DESCRIPTION... The upper level trough will finally exit to the east this weekend. A broad ridge of high pressure will settle in its place. This will lead to a southwest dominant flow across our forecast area, advecting warm air into the region. The particular airmass that is entering the region will contain abnormally warm temperatures across the eastern half of the CONUS. For our area, at the northern end of the ridge, temperatures will rise above average by around 5 degrees or so. This may lead to temperatures into the low 70s across the region this weekend. If the departing upper level trough takes longer to shift east or the center of the incoming high pressure sets up further south, these temperatures may not warm as much. If the ridge that develops is stronger than currently projected, it may have a more dominant influence over our forecast area and temperatures could trend warmer than currently projected.

Skies will be mostly clear during the subsidence pattern into this weekend, with limited available atmospheric moisture as PWATs are forecast to be less than 1 inch, falling to less than a half inch by Sunday night into Monday. Some fair weather cumulus may develop during Saturday afternoon. On Sunday, a weak trough will move through the area which could bring isolated light rain showers early Sunday morning before conditions dry out once more into Sunday afternoon, along with continued wind gusts up to 30 mph. Heading into Monday, there exists the potential for rapidly dropping dewpoints resulting in relative humidity that could plummet below 30 percent, as forecast soundings show steep lapse rates and a deep pocket of dry air in the mid levels.

KEY MESSAGE 2...Scattered thunderstorms possible Tuesday and Wednesday afternoons.

KEY MESSAGE 2 DESCRIPTION... Southwest winds return the warm, more moist air advection to the area Tuesday into Wednesday, re-energizing the atmosphere with fuel that could support isolated thunderstorm development. Early global guidance suggests CAPE values could approach 1000 J/kg with around 40 kts of bulk shear, and these ingredients could help with not only thunderstorm development but sustaining thunderstorms for a longer duration. Thunderstorms could be possible across the forecast area, but forcing and available moisture will be greatest in the north closer to the lingering warm front.

AVIATION /09Z FRIDAY THROUGH TUESDAY/

Today...VFR north, MVFR for KBGR/KBHB in scattered showers. E to NE wind 5 to 10 kt.

Tonight...VFR. S to SW wind 5 to 10 kt.

Saturday...VFR. W to SW wind 10 to 15 kt.

Saturday night - Sunday...Generally VFR across all terminals. Isolated -SHRA possible early Sunday morning. W to NW winds 10 to 15 kts gusting 20 to 25 kts.

Sunday night - Monday night...VFR. NW winds 5 to 10 kts, shifting S by Monday night.

Tuesday...Overall VFR, with MVFR/IFR possible in any rain showers. Low cigs most likely at northern terminals. Scattered thunderstorms in the afternoon. SW winds 5 to 10 kts.

MARINE

Small Craft Advisory remains up into Saturday with seas ranging from 5 to 7 ft.

Seas 4 to 7 ft Saturday night into the day on Sunday will begin to gradually decrease late Sunday into the beginning of next week. Winds gusting 20 to 30 kts will also decrease through the day on Sunday, remaining below small craft advisory criteria through the first half of the upcoming work week.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 8 AM EDT Saturday for ANZ050-051.