textproduct: Caribou

WHAT HAS CHANGED

Adjusted winds for tonight through Monday, along with temperatures. Added light snow showers this morning to the entire area.

KEY MESSAGES

1) Cold Arctic air and gusty winds will result in frigid wind chills tonight into Sunday morning.

2) Pattern turns seasonable and becomes favorable for a storm system late week nearby but a lot of uncertainty in operational and ensemble members.

DISCUSSION

KEY MESSAGE 1...Cold Arctic air and gusty winds will result in frigid wind chills tonight into Sunday morning.

KEY MESSAGE 1 DESCRIPTION... Cold Arctic air will be across the area tonight into Sunday morning. This will combine with gusty northwesterly winds as a result of the pressure gradient between high pressure building in from the west and low pressure well to our southeast. The result will be bitter cold wind chills tonight into Sunday morning with the lowest winds chills in the Western Highlands. The frigid wind chills will result in the risk of hypothermia and frostbite. Anyone venturing outside is advised to dress very warmly and cover any exposed skin.

KEY MESSAGE 2...Pattern turns seasonable and becomes favorable for a storm system late week nearby but a lot of uncertainty in operational and ensemble members.

KEY MESSAGE 2 DESCRIPTION... The latest ensemble forecasts for the AO are turning positive as the PNA goes negative and NAO turns neutral. This is a strong signal that the pattern turns more seasonable across the area with positive 500mb height anomalies developing. High temperatures in the 20s to 30s and many locations getting above 32F during the day with overnight lows in the teens. Under weak La Nina conditions the transitional period of the subseasonal teleconnections typically brews a storm system. Given the AO going positive this favors the northern stream jet and southern jet shifting north over the CONUS into a more favorable position to develop a storm system in the Northeast. We are still seeing some signs of this in the operational models, ensemble members and AI models. However, not looking like a large system and being a more progressive northern stream system. Since we are looking at a Wednesday to Friday timeframe there is a wide range of possibilities. The energy associated with this possibility is currently in the North Pacific south of Alaska. Operationally much of the models whether it is GFS, ECMWF or Canadian and their AI models continue to keep the northern and southern jet separated with phasing issues. Will continue to monitor the trend...NBM POPs did increase a little bit due to operational modeling showing a system riding through the area on the northern stream in the form of a 500mb shortwave. We are looking at chance POPs during this timeframe and could not find a reason to change that for now.

AVIATION /13Z SATURDAY THROUGH WEDNESDAY/

Today...VFR to occasionally MVFR conditions are expected across the area today. Some patchy light snow showers may lower the vsby to 5 to 7 miles at times, mainly through midday. Winds north 5 to 10 kt.

Tonight...MVFR To occasionally VFR north and VFR south. N winds increasing to 10 to 15 kt with gusts to 20 kt.

Sunday...VFR except occasionally MVFR in the far north. NW winds around 15 kt with gusts to 25 kt.

Monday...VFR. NW winds 10-15kt with gusts up to 25kt.

Tuesday...VFR. NW winds 5-15kt.

Wednesday...VFR. Possible lower due to cigs/vsby. -SN/-SHSN possible. E winds 5-10kt.

MARINE

North winds will increase to gale this afternoon and remain gale through Sunday morning. A freezing spray advisory will be up from early Sunday morning through the day on Sunday for the combination of gale force north winds will bitter cold Arctic air. Seas around 2 to 3 ft today build up to 6 ft tonight into Sunday.

Small Craft Advisory level wind gusts expected Sunday night through Tuesday morning gusting up to 30kt. Moderate freezing spray expected through late Monday AM and the Freezing Spray Advisory will continue till 10AM EST Monday. Light freezing spray is expected through midday Tuesday. Seas 2-5ft on Monday then 1-3ft on Tuesday. Winds/seas expected to be below SCA conditions on Wednesday. Beyond that there is possible SCA conditions again heavily dependent on if a storm system develops near the waters.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Cold Weather Advisory from 7 PM this evening to 10 AM EST Sunday for MEZ003-004-010. MARINE...Gale Warning from 4 PM this afternoon to 1 PM EST Sunday for ANZ050>052. Freezing Spray Advisory from 4 AM Sunday to 10 AM EST Monday for ANZ050>052.