textproduct: Caribou

WHAT HAS CHANGED

- Increased confidence in severe storm potential for today, given continued trends of elevated instability in CAM models.

KEY MESSAGES

1) Cold front passes today into Monday, bringing widespread rain, winds, and potential severe thunderstorms.

DISCUSSION

KEY MESSAGE 1...Cold front passes today into Monday, bringing widespread rain, winds, and potential severe thunderstorms.

KEY MESSAGE 1 DESCRIPTION... Occluding low pressure system moves in from the west. By this morning, warm front moves across the region, bringing in plenty of moisture. Pre-frontal troughing could help produce some morning showers across the northern areas, which could use up some of the instability in the northern region before the primary severe threat later in the afternoon. Anticipating partially to mostly cloudy skies during the day today, but frontal passage will provide enough lift for storm development.

In terms of the severe threat, there is a plethora of favorable parameters to hint at severe storm development. During the afternoon period, elevated levels of CAPE >1000-1500 J/kg, low- level lapse rates 8-9 C/km, PWATs roughly 1.25 - 1.50 inches and a couple hundred J of DCAPE point towards the chance for severe thunderstorms that could produce heavy rain and gusty winds. There is a chance for some small hail to develop with these storms. There is a non-zero chance for tornado development as well, with low LCL heights, and plenty of shear. Highest areas of concern are the Central Highlands and Upper Penobscot Valley. Additionally, periods of heavy rainfall on already moist soil could cause some hydro concerns, leading to some potential flooding in localized areas. For reference, 1-1.5 inches of rainfall within 1 hour, in regions north of Bangor, could cause flooding. Make sure to have multiple ways to get warning information, and stay weather aware!

AVIATION /06Z SUNDAY THROUGH THURSDAY/

Today and tonight...Generally MVFR/IFR today, in periods of rain showers and thunderstorms at KFVE/KCAR/KPQI/KHUL. KBHB could drop below IFR in fog development. Otherwise, generally VFR at KBGR and KBHB. Thunderstorms at northern terminals could bring periods of heavy rain, gusty winds, and lightning. LLWS starts late tonight at KCAR/KPQI/KHUL/KBGR/KBHB. Ran showers continue into tonight, but thunderstorm potential decreases past midnight.

Monday...MVFR or lower possible Monday morning, with some morning fog. Also isolated thunderstorms possible at Downeast terminals Monday morning. Potential for isolated thunder at KFVE and KCAR Monday evening. S winds 5-10KT shifting to W winds, with gusts 15-20KT.

Monday night-Wednesday...VFR. WSW G15-20KT possible Tuesday afternoon.

Thursday...MVFR/IFR in rain showers and possible TS. SE winds 10-15 kts.

MARINE

Winds and seas ramp up to Small Craft criteria tonight, over all waters. Fog is expected to develop overnight, reducing visibility. Rain showers possible Monday. Winds from the S today into Monday.

Conditions drop below small craft levels on Monday afternoon and remain that way into the middle of next week.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory from 8 PM this evening to 8 AM EDT Monday for ANZ050>052.