textproduct: Caribou

WHAT HAS CHANGED

Increased confidence in above normal temperatures this week, including at least around 10-15 degrees above normal from Tuesday into the upcoming weekend.

KEY MESSAGES

1) Above normal temperatures through the end of this week, along with multiple rounds of rainfall, will lead to continued, if not complete, ice break up on all northern rivers.

DISCUSSION

KEY MESSAGE 1... Above normal temperatures through the end of this week, along with multiple rounds of rainfall, will lead to continued, if not complete, ice break up on all northern rivers, as well as the melting of any remaining snowcover not in forests. This could lead to some isolated hydrologic issues across portions of the North.

KEY MESSAGE 1 DESCRIPTION... The region will remain under the northern periphery of a deep layered ridge centered over the Gulf of America Monday night through Saturday, with multiple northern stream shortwaves progged to be embedded in the mean westerly flow passing through the region during this time frame.

The result will be a continued warming of temperatures through the week, as well as multiple rounds of rain across the region. The combination of the increasing temperatures (with most areas likely will see temperatures remain above freezing during this time frame), along with the periods of rainfall, result in the flushing out of ice across most, if not all northern rivers, with thawing degree hours well above 1,000 and possibly exceeding 2,000. In addition the unseasonably mild temperatures and rainfall also should melt the remaining snow cover across the North, except for that not inside forests/well covered by trees. The combined result of the snow and ice melt, along with the aforementioned precipitation could cause the minor flooding of known poor drainage areas/low spots, especially at those locations highly prone to ice jam flooding.

The first of the northern stream shortwaves exits to the east Monday night, with some isolated to scattered showers and lows around 15-20 degrees above normal.

The next northern stream shortwave approaches Tuesday afternoon then crosses the area Tuesday night. This could produce from around 1/10th to 1/3rd of an inch of rainfall. Highs on Tuesday should be around 5 to 15 degrees above normal, with the largest departure across interior Downeast Maine, the Bangor/Penobscot Region and the southern Central Highlands.

The next shortwaves approaches Wednesday night, passes to the north Thursday and Thursday night, followed by the passage of a stronger northern stream shortwave trough Friday. Models differ on the timing and strength of these shortwaves, but all indicate the potential for at least 1/4" of rainfall. Temperatures continue to be well above normal, with lows mainly in the 40s and highs on Friday from around 60 to the mid 60s across the interior, but still quite a bit cooler near the immediate coast. Saturday should be as warm, if not a few degrees milder than Friday as deep layered ridging builds over the region, bringing dry conditions with minimal cloud cover.

AVIATION /06Z SUNDAY THROUGH THURSDAY/

Today...VFR. NW 5-10kts.

Tonight...VFR early, diminishing to MVFR by 06z and IFR after that time from south to north. S 5-15kts gusts to 20kts. LLWS likely after 06z.

Monday...IFR all terminals in rain. S 5-15kts gusts to 20kts, becoming SW late. LLWS continues.

Monday night...MVFR or lower possible to start, becoming VFR late. NW winds G15-20KT possible. LLWS possible Monday evening.

Tuesday...VFR, with a low chance of MVFR late.

Tuesday night: MVFR or lower possible. LLWS possible.

Wednesday: VFR.

Wednesday night-Thursday...IFR or lower possible. LLWS possible Thursday.

MARINE

SW winds look to increase above small craft levels after 06z Monday and continue through Monday night. Ocean waters may see a few gusts to 35kts but expect these will be few and far between given stable airmass, thus have issued a Small Craft Advisory for all waters. Seas increase by Monday morning and will remain elevated into Tuesday morning.

Gales are possible on the coastal ocean waters with SCA conditions likely on the intra-coastal waters Monday night. SCA conditions are then probable on the coastal ocean waters Tuesday, with sub-SCA conditions elsewhere. All waters should then see sub-SCA conditions from Tuesday night-Thursday night.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory from 2 AM Monday to 8 AM EDT Tuesday for ANZ050-051. Small Craft Advisory from 2 AM Monday to 2 AM EDT Tuesday for ANZ052.