textproduct: Gray - Portland

WHAT HAS CHANGED

No major changes to the going forecast at this time other than to lower min temps tonight and Wednesday night closer to statistical guidance.

KEY MESSAGES

1. Fair weather with warming temperatures through Thursday. Some valley fog possible in the CT River Valley tonight.

2. Temperatures remain well above normal Friday, while southern and coastal locations could see the heat linger into Saturday. A cold front looks to bring relief into the second half of the weekend, along with some scattered showers and thunderstorms. Temperatures early next week return closer to normal for early June.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Upper level ridging builds in tonight through Thursday. The result through the period will be dry weather, warming days, and somewhat chilly nights at the better radiators. The only caveat will be an isold shower on the Midcoast until around sunset this evening. Some patchy valley fog possible again tonight in the CT river valley. In addition, lowered min temps tonight closer to statistical guidance. This yielded mid to upper 30s in the mountain valleys so there may some some patchy frost.

Otherwise we'll continue to warm up through the period with relatively light winds and afternoon seabreezes. By Thursday highs should be in the mid to upper 80s.

KEY MESSAGE 2 DESCRIPTION...

Heat spell continues Friday and perhaps into Saturday ahead of a cold front that looks to cross the forecast area this weekend. Impinging front Thursday night NW of New England will begin to collapse an otherwise dominant ridging pattern in northern New England. Recent trends have delayed this passage, with any meaningful impact on temperatures not taking hold until Saturday night.

Current forecast keeps Friday dry and hot, with NBM temps reaching the mid to upper 80s across the interior and coast. Record highs could be attainable at Portland should winds remain westerly/offshore, but some guidance suggests winds over the coastal waters becoming southerly into the afternoon. This could have more an impact to the peninsulas of the Midcoast than much of the southern coast. Thus it will depend on background winds being strong enough to offset the potential for a seabreeze, which could be strong given the land/sea temp gradient.

Front attempts to sink further into the forecast area Saturday, and this is reflected in forecast highs. It could be another warm day for southern NH into far southern ME where mid 80s will be attainable, but highs top out in the 70s and lower 80s for much of the northern half of the CWA. This front will also bring the chance of showers and some embedded thunder to the area. There is enough of a signal for CAPE to keep thunder in the forecast for Sat afternoon, but still a wide spread to determine if more organized storms are possible.

The front looks to make its full transit Saturday night into Sunday, which will bring temps back towards normal Sunday and into early next week. High pressure to the north should usher precip associated with the front south, but there is some variance on timing. With the moisture stream squeezed between highs to the north and south, IVT likely eclipses 250 kg/m/s as it advects from the Great Lakes. This would lead to increased precip rates Sat night - Sun, but not currently concerning for flood potential.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Through Thursday...VFR conditions prevail through Thursday with afternoon seabreezes. Some valley fog possible tonight in the CT River Valley.

Outlook:

Wednesday/Wednesday night: VFR with light winds.

Friday: High pressure is favored with VFR conditions. However, a sagging cold front may bring a few showers and storms to the western ME mountains late Friday. These could create TEMPO IFR restrictions should they pass over any terminal.

Saturday: Local MVFR to IFR conditions possible in sct showers and storms, mainly for northern NH and far western ME. This pushes south overnight.

Sunday: Showers and storms may linger and continue to bring the possibility of TEMPO IFR TO MVFR restrictions, particularly in more persistent RA.

MARINE

Conditions will remain below SCA levels through Thursday with warming temperatures as high pressure dominates the weathermap.

A cold front will attempt to cross the waters this weekend, but timing is variable between Saturday and Sunday.

GYX WATCHES/WARNINGS/ADVISORIES

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