textproduct: Caribou

SYNOPSIS

Low pressure slowly exits through the Maritimes as high pressure builds in from the west tonight through Monday night, with the high also exiting to the east on Tuesday. An area of low pressure passes to the north Tuesday night into Wednesday night, followed by high pressure on Thursday, then a second low passing to the north Thursday night though Friday night. High pressure builds in on Saturday.

NEAR TERM /THROUGH TUESDAY/

*Key Messages 1) Cold and Windy Today 2) Warming Trend Begins Tuesday

Discussion...

Today will feature a surface low pressure system deepening in the Maritimes as a high pressure system over the Southeastern United States strengthens over the East Coast. Maine will be on the northern fringe of this ridge with strengthening pressure gradient overhead. Hi-Res modeled soundings showing a well mixed boundary layer up to 3kft today. Good agreement evident in NBM 5.0 QMD Max Wind Gusts reaching 25-35kt across the CWA. This matches well with GFS, ECMWF, ECMWF AIFS, NAM3km and HRRR plots of the top of the mix layer at 25-35kt winds. Given this strong agreement have opted to blend winds today with the NBM90th to increase speeds and then peak gusts this afternoon closer to the NBM5.0 QMD Max Gusts. This results in widespread NW wind gusts of 30-35mph with some gusts across the higher terrain of 40-45mph possible. Most breaks of sunshine this morning especially in the southern half of the CWA will quickly fill with diurnally driven cloud cover thanks to cold air aloft. This is compounded with our low peak sun angles across the state, peak sun angle CAR is 19.9deg and 21.9 deg at BGR today. Highs top out in the middle teens across the Central Highlands, North Woods and the entire Crown. Bangor Region along the Airline to Calais looking at highs in the upper teens and low to mid 20s for the Downeast coast. Wind Chills today, what it feels like to bare skin, will be around 0F across the North, single digits below zero Moosehead Region, 3-8F for Bangor to Downeast Coast.

Tonight a weak 500mb open shortwave will pivot through and relax the winds and help weaken the surface gradient. Expecting a trend to partly cloudy skies and temperatures falling back into the 0-5F range for the northern 2/3rd of the CWA and 5-10F for the southern 1/3rd. Any locations with 5-15mph winds tonight will see wind chills fall back into the 5-10 degrees below zero.

Tuesday the 500mb flow turns zonal and surface ridging along the US East Coast takes hold in Maine. Winds will shift SW through the morning hours at 5-10mph. 925mb temps warm and with partly to mostly sunny skies expecting highs to top out in the low 20s north and mid to upper 20s for the Highlands to Bangor region and 32-36F for the Downeast coast. This will be the start of a warming trend which will be described in more details below...

SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/

|Key Messages 1) Temperatures rise Tuesday night

Ridge axis, both at the sfc and aloft will be in control of areas/s wx Tuesday evening. Surface low will be crossing James Bay late Tuesday night with warm front lifting through the region. This results in temps rising overnight with temps in the upr teens/lwr 20s rising into the lwr/mid 20s by 12z Wednesday. At the same time southerly winds will increase with gusts up to 15-20kts by morning acrs the area.

Warm advection snow showers expected to move into wrn zones Wednesday afternoon with upr trof moving acrs the area overnight. Fropa occurs late Wednesday evening with colder air moving in after midnight Wednesday night, with low temps dropping into the single digits and low teens over the north.

LONG TERM /THURSDAY THROUGH SUNDAY/

Key Messages 1) Strong synoptic winds Thursday night 2) Gusty winds expected Friday with cold front passage 3) Potential for flash freeze late Friday afternoon

High pressure will build in from the west on Thursday before next system winds up over the upr Midwest. Upr low will be digging south out of the Prairie Provinces Thursday morning with sfc low intensifying in RRQ of upr jet. By 12z Thursday low will likely be in the vicinity of Lk Superior with warm front draped toward the Mid-Atlantic with cold front dropping thru the MS River Vly.

High pressure will build east Thursday night with increasing southerly flow ahead of the system. Temps will begin to rise Thursday morning with LLJ strengthening twd 50kts 00z Friday, possibly as high as 60-75kts by 12z Friday. Have started to increase southerly winds Thursday night into Friday with LLJ but will likely need to be increased more through the coming week. Bulk of the precipitation likely to fall as rain overnight with patchy fog expect in warm and humid airmass falling over cold snowpack. Current snowpack temp around 15F looks to rise to around 20F over the next two days. Assuming that the snowpack temp remains in the 20s when rain falls Thursday night and Friday, expect that snow should be able to absorb the rainfall. As of this time, model guidance indicates a quick 0.50-0.75 inches falling by the end of the week.

Latest guidance brings cold frontal passage at some point on Friday afternoon. Cannot rule out convective showers passing thru the CWA in the afternoon, and depending on timing, potential exists for mixing down high winds with fropa. Cold air follows rapidly with air temps dropping below frzg in a very short period of time. Too early yet to talk about the potential for a flash freeze but it appears all cards are on the table at this point. Precip looks to end as snow showers in wrap-around Friday afternoon into the evening hours.

After this system exits into the Maritimes next system will be following quickly on it/s heels with the next chc for precip moving in on Saturday evening.

AVIATION /06Z MONDAY THROUGH FRIDAY/

NEAR TERM: Northern Terms...This morning seeing VFR/MVFR cigs and -SHSN at the terms. Expecting low end VFR to high end MVFR cigs, confidence is low but expecting varying cigs BKN-OVC 025-035 at most sites. Today winds will increase W-NW 10-20kt with gusts up to 30kt. Tonight winds will relax and shift W-WSW 5-15kt. Expecting VFR cigs tonight and then SKC to BKN high cigs on Tuesday with W-SW winds 5-10kt.

Southern Terms...VFR cigs and VCSH/-SHSN this morning expecting VFR cigs today. Today winds will increase W-NW 10-20kt with gusts up to 30kt. Tonight winds will relax and shift W-WSW 5-15kt. Expecting VFR cigs tonight and then SKC to BKN high cigs on Tuesday with W-SW winds 5-10kt.

SHORT TERM: Tuesday night...Mainly VFR, though may see MVFR cigs north late. S 5- 10kts, gusts 15-20kts late.

Wednesday...VFR Downeast terminals, MVFR/IFR in light snow northern terminals. SSW 5-15kts gusts to 20kts.

Wednesday night...Improving to VFR north. WSW 5-15kts.

Thursday...VFR. S 5-15kts, gust 20-25kts. LLWS possible.

Thursday night-Friday...IFR in rain, possibly lower. LLWS Thursday night and Friday morning. S 10-20kts gusting to 25-30kts Thursday night, with gusts 30-35kts Friday afternoon.

MARINE

NEAR TERM: Gale Warning remains in effect until 7PM EST this evening for the Coastal Waters. NW winds 20-30kt with gusts up to 40kt and seas 5-8ft. On the Intra-Coastal Waters a Small Craft Advisory is in effect until 7PM EST this evening. NW winds 15-25kt with gusts up to 30kt and seas 2-4ft. Light freezing spray is expect today into tonight on all the waters. Winds/seas will fall below SCA criteria by daybreak Tuesday. Winds/seas below SCA criteria for the day Tuesday but winds shifting SW will begin to ramp back up late day. Sea surface water temperatures range from 44-47F from the Downeast coast out 25nm including Penobscot and Passamaquoddy Bays.

SHORT TERM: SW winds increase toward gale force again over the waters late Tuesday evening, continuing into Wednesday. Winds diminish aob sca levels Thursday morning before increasing back to gale force from the south Thursday evening before shifting from the west late Friday afternoon. Seas increase above 5ft late Tuesday night to as high as 12ft over the outer waters Wednesday afternoon. Seas diminish slightly before ramping up again toward 14ft Friday afternoon.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Gale Warning until 7 PM EST this evening for ANZ050-051. Small Craft Advisory until 7 PM EST this evening for ANZ052.