Marine Weather Net

Casco Bay Marine Forecast


THIS AFTERNOON

NE
WINDS
5 KNOTS

TONIGHT

SW
WINDS
5 - 10
KNOTS

FRI

NE
WINDS
5 KNOTS

FRI NIGHT

S
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
ANZ153 Forecast Issued: 925 AM EDT Thu Jul 19 2018

This Afternoon...Ne Winds Around 5 Kt, Becoming S With Gusts Up To 20 Kt. Seas 1 To 2 Ft.
Tonight...Sw Winds 5 To 10 Kt, Becoming W After Midnight. Seas 1 To 2 Ft.
Fri...Ne Winds Around 5 Kt, Becoming S In The Afternoon. Seas 1 To 2 Ft.
Fri Night...S Winds 5 To 10 Kt, Diminishing To Around 5 Kt After Midnight. Seas 1 To 2 Ft.
Sat...Se Winds 5 To 10 Kt. Seas 1 To 2 Ft.
Sat Night...E Winds 5 To 10 Kt. Seas 2 To 3 Ft. A Chance Of Showers In The Evening, Then Rain Likely After Midnight. Areas Of Fog. Vsby 1 To 3 Nm.
Sun...E Winds 5 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft. Rain With Tstms Likely. Areas Of Fog. Vsby 1 To 3 Nm.
Sun Night...S Winds 5 To 10 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft. Showers Likely With A Chance Of Tstms.
Mon...S Winds 5 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft. Showers Likely With A Chance Of Tstms.
Mon Night...S Winds Around 10 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft. A Chance Of Showers. Winds And Seas Higher In And Near Tstms.
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Area Forecast Discussion
National Weather Service Gray ME
930am EDT Thu July 19 2018

Synopsis: High pressure will crest over the region today and will shift offshore overnight. High pressure will hold offshore Friday through Saturday. A warm front will approach from the south Saturday night and will lift north into the region on Sunday. A warm and humid air mass will prevail behind the front early next week.

Near Term - Until 6pm This Evening
930 am Update: Very quiet day under the large ridge of high pres. No changes needed attm.

700 Am Update... Quick update to mainly adjust area temps/tds. Patchy valley fog is quickly dissipating and skies are crystal clear across the region. No majors planned to current forecast.

Prev Disc... Another fine mid summer day on tap as high pressure gradually crests over the region by late in the day. Will see a chilly start to the day in valleys in the mountains and foothills where temperatures are already in the 40s. Highs today will top out near normal ranging from the mid 70s north to the lower 80s south

Short Term - 6pm This Evening Through 6pm Friday
High pressure will slide offshore overnight and will hold there through Friday as quiet weather continues across the northeast. Looking for clear skies Thursday night with lows from the mid 40s to mid 50s. Return flow will bring slightly warmer temperatures on Friday with most areas reaching the lower to mid 80s under mostly sunny skies

Long Term - Friday Night Through Wednesday
Not much change to the forecast as latest 00z deterministic guidance and latest forecast ensembles continue to be in general agreement with the upcoming pattern change. Dry weather will be replaced by a tropical airmass by Sunday and should continue in place through much of next week. This will mean we stand a good chance at beneficial rainfall.

High pressure ridging in place across the northeast should provide fair weather Friday night into Saturday. However, with tropical air mass looming to our south, low clouds and some fog may begin to roll in late Saturday along the coast as winds turn more onshore.

A short wave trough originating from off the southeast US coast will swing northward Saturday night into Sunday along with varying degrees of strength of attendant SFC low pressure seen the latest model guidance. This short wave trough will bring north a tropical airmass. In fact precipitable water values should go from around 50% of normal to nearly 200% of normal in roughly 12-18 hours ending midday Sunday. That is a serious air mass change and one that will support occasionally heavy rain on later Saturday night and Sunday along with a few thunderstorms. Confidence in rainfall totals not overly high at this time as degree and placement of forcing for ascent is still in question. There may even be some mesoscale enhancement as some guidance shows coastal front development.

Confidence is high enough in the occurrence of rainfall that we can go with Probability of Precipitation around 80 percent on Sunday.

Thereafter, Bermuda high pattern remains in place allowing for a very moist airmass to persist through midweek. Pegging down forcing mechanisms for rainfall timing is difficult this far out in time. However, there will be substantial chances for showers and thunderstorms Monday through Wednesday - mainly during the afternoon hours with peak heating and quite possibly mainly in the interior zones where less subsidence may be found. Will have to watch out for localized flash flooding during this period with very high PWATS in place.

Marine Discussion
Short Term: No flags as high pressure keeps winds light.

Long Term: Small Craft Advisory conditions, especially 5+ foot seas, possibly develop Saturday night and may last into early next week

NOAA Gray/Portland ME Office - Watches - Warnings - Advisories
ME...None. NH...None. MARINE...None

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