textproduct: Caribou

WHAT HAS CHANGED

- Updates to the Aviation section below for the issuance of the 00z TAFs

KEY MESSAGES

1) Scattered to isolated afternoon showers, along with possibly a rumble of thunder this afternoon across the North, through Tuesday afternoon. The showers/storms this afternoon will be over Northern Maine, and Tuesday afternoon will be Downeast.

2) Much warmer Wednesday through Friday, with two dry days in a row area wide Wednesday and Thursday.

DISCUSSION

KEY MESSAGE 1... Scattered to isolated afternoon showers, along with possibly a rumble of thunder this afternoon across the North, through Tuesday afternoon. The showers/storms this afternoon will be over Northern Maine, and Tuesday afternoon will be Downeast.

KEY MESSAGE 1 DESCRIPTION... Shortwaves continue to push through on the west side of a closed low over the eastern Maritimes into Tuesday. This evolves into a full latitude trough by Tuesday afternoon, with the trough axis passing offshore by Tuesday evening.

This afternoon/early this evening, the main forcing associated with this system is over the North, where isolated showers are forecast. With only a few hundred J/kg of CAPE, Showalter Indices around 2, and only 20-25 kt of bulk shear, so not expect any strong, yet alone severe, storms this afternoon. Also would expect any showers to not linger too long after sunset, with the loss of solar heating.

The main axis of the developing upper level trough passes through on Tuesday, and offshore by late Tuesday afternoon/early Tuesday evening. With yet again only a few hundred J/kg of CAPE available and this time 50-60KT of shear, could have a case where the shear is to great for any thunderstorms. Showalters generally greater than 4 bear that idea out. So just have isolated to scattered showers in the forecast Tuesday afternoon over mainly Downeast Maine.

KEY MESSAGE 2... Much warmer Wednesday through Friday, with two dry days in a row area wide Wednesday and Thursday.

KEY MESSAGE 2 DESCRIPTION... On Wednesday, ridging builds in from the west as a high pressure system settles over the Great Lakes region. Warmer air mass with warmer temperatures expected for the end of the week. Daytime high temperatures in the low-to-mid 70s on Wednesday, upper-70s to mid-80s on Thursday, and mid-70s to low-80s on Friday. Overnight lows generally in the 50s. Not anticipating precipitation Wednesday or Thursday. Cold front begins to approach on Friday, bringing a chance for some rain showers in the afternoon into Saturday. Very slight potential for isolated thunderstorms.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Tonight: VFR across all terminals. Winds becoming light and variable. Area showers thunderstorms around KPQI and north will quickly dissipate this evening.

Tuesday: VFR across all terminals. Increasing N to NW winds becoming 5 to 10 kts with gusts 15 to 20 kts in the afternoon. KBHB and other immediate coast terminals may be the exception should they remain within the marine layer, with SW winds and possibly a sea breeze if the cold front does not arrive first. Light rain showers possible at Downeast terminals, and most likely with cold front and sea breeze boundary interactions.

Tuesday night: VFR across all terminals. Winds light and variable.

Wednesday - Thursday night: VFR. Winds shift W by Wednesday evening, and then WSW by Thursday.

Friday: VFR, with a very low chance of brief MVFR conditions at KFVE/KCAR/KPQI/KHUL in the afternoon to evening period. WNW winds around 5-10 kts.

Friday night - Saturday: MVFR in rain showers. Very slight potential for thunderstorms at KHUL/KBGR/KBHB, but too early to tell. Winds variable overnight Friday, shifting N/NE by Saturday.

MARINE

A light pressure gradient over the waters out to 60nm through Tuesday night will limit winds to around 15 kt or less and seas to 3 ft or less.

Winds and seas generally stay below Small Craft criteria Wednesday into Friday. Potential for some rain showers on Saturday into Sunday. Winds SE, that shift to the SW, Wednesday evening into Thursday. Winds SW Thursday into the weekend.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...None.