textproduct: Caribou

SYNOPSIS

An occluded front passing tonight. Low pressure then tracks across southern Quebec Thursday and Thursday night, then into the northeastern Maritimes Friday and Friday night. High pressure builds in from the west Saturday and Saturday night. Low pressure approaches from the west on Sunday. High pressure moves in on Monday.

NEAR TERM /THROUGH THURSDAY NIGHT/

6:20 p.m. Updated aviation discussion to reflect brief period of lifting ceilings tonight. Otherwise no updates to the forecast.

Key Messages -Rain, drizzle, and patchy fog will continue tonight -Mostly clear and breezy Thanksgiving day with isolated snow showers in the afternoon

The triple point of the occlusion will continue to move through the region this evening and tonight. For this evening, Upper air model soundings indicate an area of dry air at the mid levels moving in after sunset. The lower levels will remain moist, creating drizzle and patchy fog. Later tonight, rain returns as the frontal boundary move through the region. The North Woods will see more snow than rain due to the cooler airmass moving in. By Thursday, the precip will exit to the north, which will clear out some clouds. As the occlusion starts to wrap back towards New England, pressure gradients will tighten making for a breezy day. Some moisture and instability on the wrap around will bring isolated showers in the afternoon. The precip type will depend on the temps, so mainly isolated rain showers in the south and isolated snow showers in the north. For Thursday night, these isolated showers will continue in the north. Around midnight is when the showers will end with the decreasing of instability. Winds will shift to the SW and decrease slightly with temps cooling into the 20s.

SHORT TERM /FRIDAY THROUGH SATURDAY/

Key Message... -Potential for locally heavy snow showers Friday afternoon that could briefly impact travel in the north.

Friday...As a potent upper level closed low pressure moves in from the west, snow showers are likely during the day Friday, mainly in the afternoon and in the north primarily north of Lincoln. While there could be some decent snow showers around that could briefly whiten roads mainly in the north, don't anticipate enough activity for snow squall warnings. This is because there isn't quite enough wind and the atmosphere isn't quite unstable enough for showers to be heavy enough to create gusts to squall criteria. Any snow accumulations during the day Friday should be under an inch.

Friday Night and Saturday...While we can't totally rule out a few snow showers, most places should be dry Fri night/Sat. Wind gradually shifting from SW to W and remaining breezy as colder air moves in as the upper level low pressure exits to the east. Highs Saturday should be 5-10F cooler than Friday, with highs ranging from the upper 20s far north to mid to upper 30s Downeast.

Models are in good agreement through Saturday.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Key Messages... -Light snow accumulation likely Sunday afternoon/night -Possibility of a stronger storm late Tuesday

High pressure builds in Saturday night and exits to the east Sunday as the next system moves in. This system will come as a surface low passing from west to east well to our north, but we could see a weak triple point low develop over our area. Models are coming into better agreement on this system, though there is still some uncertainty on how much precipitation falls and how far north the snow is able to change to rain toward the tail end. The start time of the event has moved up some, meaning those with travel interests Sunday afternoon/evening could be impacted. Precipitation appears to develop roughly 1-5pm Sunday from west to east. Bangor looks close to the rain/snow line at first, while most areas north of Lincoln should favor snow at the onset. As we head into Sunday evening, the snow should change to rain from south to north, with the rain/snow line perhaps making it north to somewhere between Houlton and Fort Kent by the time it ends in the pre-dawn hours Monday. This system looks like a quick hitter, and best estimate at this point is 1-3 inches of snow in the north Sunday afternoon/evening, with a small chance of some spots reaching 3-5 inches if some of the colder/wetter model solutions pan out.

Very chilly air moves in behind the system, with lows Monday night dropping to 0-10F in the north and in the teens Downeast. Think there will be enough of a break between the precipitation ending and the really cold temps that flash freezing of roads is unlikely.

Next focus turns toward a possible storm late Tue/Tue night. Lots of model disagreement on this system, with some solutions bringing fairly heavy 6 inch plus snow to our area, some having the system passing just south of us with Downeast on the north edge getting a few inches of snow, and others further south with no precipitation. Definitely too early to tell, but it is something to watch. If we do get any precipitation, the airmass should be cold enough that it would fall in the frozen form, even down to the coast.

AVIATION /00Z THURSDAY THROUGH MONDAY/

NEAR TERM: Some slight improvements to MVFR at northern sites, but conditions are expected to drop back down to IFR/LIFR later this evening. Cigs and vsby are expected to remain IFR/LIFR for all terminals the rest of tonight as a brief period of precip moves through. RA may be mixed with SN in the north early tomorrow morning. By later Thursday morning, conditions will improve to MVFR, then to VFR by the afternoon. VFR conditions will remain through through Thursday night. Tonight, light and variable winds. Thursday, W winds 5-15 kts. Thursday night, SSW winds 5-10 kts.

SHORT TERM: Friday...MVFR or lower possible in any stronger snow showers at mainly northern terminals, otherwise VFR. SW winds around 10 kts with gusts 15-25 kts.

Friday night-Saturday night...VFR, with a small chance of intermittent MVFR ceilings in the north Friday night and Saturday. W wind 10 kts gusting 15-20 kts Friday night, then W 10-15 kts gusting 20-30 kts Saturday. Winds ease Saturday night.

Sunday...MVFR or lower possible in the afternoon as snow develops, with rain or snow BGR/BHB. S/SE wind increasing to 10-15 kts. LLWS possible late.

Sunday Night...IFR with mainly rain BHB/BGR, and rain or snow MLT north to PQI and FVE. S wind 10 kts with gusts to 20 kts. LLWS likely.

MARINE

NEAR TERM: A small Craft Advisory has been issued for late tonight through Thursday night.

SHORT TERM: Moved back the start of the gale watch to 12z Fri. Low end W/SW gales still possible Friday into Friday night and possibly Saturday except for the intracoastal waters. Winds then diminish dramatically Saturday night, but S gales appear likely for all waters Sunday night. Seas 5-8 ft through Saturday, then diminishing Saturday night into early Sunday, then quickly rising again close to 10 ft Sunday night.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory from 4 AM Thursday to 6 AM EST Friday for ANZ050>052. Gale Watch from Friday morning through Saturday morning for ANZ050-051.