textproduct: Gray - Portland

WHAT HAS CHANGED

Rainfall is limited across the area and have cancelled the Flood Watch. Aviation section has been updated for the 12Z TAFs.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

An unseasonably strong synoptic system continues to work its way thru the Northeast today. A deep upper trof and strong surface low for this time of year will spin thru the Gulf of Maine into the evening before finally drifting east.

Latest radar trends show limited rainfall across the area this morning and the threat for flooding has diminished. CAMs have largely struggled with handling rainfall overnight and show variability in showers redeveloping today. Models generally suggest showers and perhaps some thunder blossoms across SE NH and the coastal plain of Maine from late morning into the afternoon that could bring localized heavy rainfall. Low pressure moving east and the loss of daytime heating will see showers and storms really diminish quickly this evening.

KEY MESSAGE 2 DESCRIPTION...

By Fri conditions will have improve, but the region will remain beneath lower heights aloft. That will generally mean clearer skies early in the day followed by diurnal increase in cloud cover and the chance for scattered showers and storms. The same will be true of Sat, with any shower activity more widely scattered.

By Sun the next trof will be approaching. Upper flow will be southwesterly, more or less parallel to the frontal boundary. So I do not expect it to be moving very fast. As such I have no issue with NBM PoP being spread out over two days, into Mon. It is also possible that this front will be a play in two acts. Act one being convection forming Sun and falling apart over western zones, and act two with convection developing again Mon slightly east and departing the area by late in the day.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Through tonight: Periods of SHRA, low CIGs will lead to MVFR to IFR/LIFR through morning. Winds will be out of the northeast at 5-10kts with some potential for northeasterly wind gusts exceeding 20kts during the day. A trend towards MVFR is likely going into the afternoon while scattered SHRA/TSRA may bring lower restrictions. Dry northerly flow may allow for some VFR tonight while areas that don't scatter could see IFR/LIFR cigs.

Outlook:

Friday-Saturday: Largely VFR conditions expected. Local MVFR or lower possible in scattered showers/thunderstorms.

Sunday-Monday: Increasing chances for showers and thunderstorms may lead to areas of MVFR/IFR developing later in the day Sun thru Mon.

MARINE

Fresh east to southeast winds continue thru today, gradually becoming more northerly by the evening. SCA conditions are expected for all waters for much of the day, with winds diminishing more quickly than seas around mid afternoon. There may also be patchy marine fog thru midday.

Winds and seas are generally expected to remain below SCA thresholds thru the remainder of the forecast period. However another round of fresh onshore winds are possible Sun, and gusts may approach 25 kt outside of the bays.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ150- 152>154.