textproduct: Caribou

WHAT HAS CHANGED

- Lowered QPF amounts for the system Sunday to Monday.

KEY MESSAGES

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

2) Patchy/areas of frost possible across northern areas Monday night.

DISCUSSION

KEY MESSAGE 1...Moderate rain showers expected Sunday afternoon into Monday morning but should have minimal impact on drought.

KEY MESSAGE 1 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 into 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 120+ kt upper jet. While surface based CAPE below 200 J/kg is expected across this area serves as a limiting factor, mid-level lapse rates of 6.5-7 C/km are forecast. So some elevated convection, possibly even a rumble of thunder in the afternoon/early evening hours is possible. The best chance for any (elevated) thunder is across the North Woods and just offshore.

Precipitable water values should range from 1.25 to 1.5 inches across the North and 1.5 to 1.75 inches elsewhere. Around a third of an inch of rain is likely along the coast and the St. John Valley, with lower amounts 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.

KEY MESSAGE 2...Patchy/areas of frost possible across northern areas Monday night.

KEY MESSAGE 2 DESCRIPTION... High pressure will build across the region behind the cold front Monday, bringing 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. Patchy/areas of frost are possible Monday night in the normally colder low lying locations.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

High confidence in VFR at KFVE/KCAR through the TAF period. High confidence in VFR through at least 00z tonight at KBGR/KBHB, then there is a chance for MVFR or lower conditions by around midnight. For KHUL/KPQI is there is a chance for MVFR or lower conditions through around sunrise this morning, then high confidence in VFR from 12z-00z. There is then a low chance for MVFR or lower at those two locations for the remainder of the TAF period. This chance is to low to reflect in the TAFs at this time.

Light and variable winds become S-SSW at around 10kt this afternoon. There is also a small chance for isolated wind gusts of 15-20kt this afternoon as well. The confidence in this occurring is to low to place in the TAFs at this time. Winds become light and variable again this evening KHUL/KBGR/KBHB.

Late tonight/early Sunday morning: VFR at northern terminals, MVFR or lower possible KBHB/KBGR. LLWS possible.

Mid Sunday morning-Sunday afternoon: MVFR or lower possible. Thunder possible at far NW terminals late in the afternoon. LLWS possible. S winds G15-20KT possible.

Sunday night: MVFR or lower in rain showers. Some river valley fog is possible near KPQI and KHUL. S/SW winds 5-10 kt gusting to 20 kt.

Monday: MVFR early, improving to VFR. NW winds 10-15 kt gusting to 25 kt.

Monday night-Wednesday...VFR.

MARINE

All waters should experience sustained winds less than 15 kt, gusts less than 20 kt and seas 4 ft or less through Wednesday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Frost Advisory until 8 AM EDT this morning for MEZ001>006. MARINE...None.