textproduct: Caribou

WHAT HAS CHANGED

- 745 PM Update: Increased PoPs further south and in time a few more hours based on visible outflow boundary interaction as seen on current radar and satellite imagery. Updates to aviation section below with the 00z TAFs.

- Confidence has increased in thunderstorms Sunday afternoon and evening.

KEY MESSAGES

1) Cold front passes Sunday into Monday, bringing widespread rain and thunderstorm chances. Some storms could become severe.

DISCUSSION

KEY MESSAGE 1...Cold front passes Sunday into Monday, bringing widespread rain and thunderstorm chances. Some storms could become severe.

KEY MESSAGE 1 DESCRIPTION... A large occlusion centered over the Hudson Bay will swing the triple point towards the region Saturday night into Sunday. By Sunday morning, the warm front should stretch across the north, bringing warm, moist onshore flow. By Sunday afternoon, the triple point begins to intensify, which increases rain potential and instability. The cold front should move through the area in last afternoon to early evening. As of this update, the CAMs models have capture much higher instability than previously forecast, mainly across the north. The MUCAPE and MLCAPE have increase to +1000 J/kg with lapse rate steepening throughout the afternoon. Bulk wind shear has also increased with the front. Parameters look more severe with some parameters triggering towards gusty winds with a low chance of tornado development. More updates will be needed to build confidence.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Tonight...BHB and FVE drops to IFR in low stratus and fog through morning. BGR and HUL will see hints of low clouds with potential for very brief IFR conditions (<10%). Fog may develop near other terminals, but less likely to decrease visibility (10-15% chance for vis dropping to IFR/LIFR).

Sunday...VFR for Aroostook terminals early dropping to MVFR/IFR in locally heavy rainfall and tsra in the afternoon and evening. Downeast terminals improving to VFR in the morning. S winds 5-15kts gusting to 20-25kts in the afternoon.

Sunday night...MVFR/IFR in showers Aroostook terminals. MVFR/IFR in low clouds and fog Downeast terminals. SSE winds 5-15kt. LLWS possible at BGR and coastal terminals.

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. S winds 10-15 kts.

MARINE

Winds and seas will remain small craft levels over all waters through Sunday. Fog will reduce visibilities this evening and overnight. South winds gust above 25 kts Sunday night into Monday morning out to 60NM with seas exceeding 5ft over ocean and outer waters.

Conditions drop below small craft levels on Monday afternoon and remain that way into the middle of next week. Showers and thunderstorms will pass through the waters Sunday night into Monday. Fog will reduce visibilities over the waters tonight and tomorrow night.

CAR WATCHES/WARNINGS/ADVISORIES

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