textproduct: Caribou

WHAT HAS CHANGED

- Issued a Frost Advisory for northern areas from 2 AM to 8 AM Saturday.

KEY MESSAGES

1) Patchy/areas of frost possible across northern areas later tonight.

2) Moderate rain showers expected Sunday afternoon into Monday morning but should have minimal impact on drought expected.

DISCUSSION

KEY MESSAGE 1...Patchy/areas of frost possible across northern areas later tonight.

KEY MESSAGE 1 DESCRIPTION... High pressure will build across the region overnight with clear skies and light winds. This will result in favorable conditions for radiational cooling. Low temperatures will range from the mid to upper 30s across much of northern Maine where a Frost Advisory has been issued. Patchy/areas of frost are possible late tonight in the normally colder low lying locations. Patchy river valley fog is also possible late tonight.

KEY MESSAGE 2... Moderate rain showers expected Sunday afternoon into Monday morning but should have minimal impact on drought expected.

KEY MESSAGE 2 DESCRIPTION... A northern stream trough tracks across southeastern Canada from Sunday afternoon into late Sunday night, then crosses Maine from early Monday morning into early Monday evening. At the surface a cold front will approach Sunday, then cross the area Sunday night and Monday morning. This should bring some scattered to possibly numerous showers to the region from late Sunday afternoon into Monday morning. The strongest forcing will be across the North, with that area in the left rear quadrant of a developing 110+ kt upper jet. Instability below 200 J/kg is expected across this area with mid-level lapse rates of 6.5-7 C/km. So some elevated convection, possibly even a rumble of thunder (best chance for the latter is across the North Woods, with the best forcing) is possible.

Precipitable water values should range from 1.25 to 1.5 inches across the North and 1.5 to 1.75 inches elsewhere. Given the very dry antecedent conditions, other than possibly some ponding of water on roadways, no significant impacts are expected. As of now, this is not expected to have any appreciable impact on ongoing drought across the region.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

Rest of this afternoon...VFR. Northwest winds 10 to 15 knots with gusts up to 25 to 30 knots.

Tonight...Variable conditions with any patchy fog late. Otherwise, VFR. Northwest winds 5 to 10 knots, becoming light and variable.

Saturday...VFR. Variable winds 5 to 10 knots, becoming south 10 to 15 knots.

Saturday night...VFR early, then VFR/MVFR occasional IFR. South winds 10 to 15 knots.

Sunday to Monday morning...MVFR or lower likely, becoming VFR by late Monday morning. LLWS possible Sunday afternoon/evening. S winds 10-15kts gusting to 25kts turning NW diminishing to 5-10kts overnight.

Monday afternoon to Tuesday morning...VFR. NW winds 10-15kts gusting up to 25kts Monday afternoon becoming light overnight.

Tuesday afternoon into Wednesday... VFR. NW winds turning S 05-10kts.

MARINE

Winds/seas below small craft advisory levels tonight through Saturday night. Sustained S winds of 15 kt or less with gusts of 20 kt or less turning NW Monday morning and persisting through Wednesday. Seas of 4 ft or less are forecast for all waters Sunday through Wednesday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Frost Advisory from 2 AM to 8 AM EDT Saturday for MEZ001>006. MARINE...None.