Marine Weather and Tide Forecast for North Eastham, MA

NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/
Key Messages...

* A brief spot snow shower possible across western MA/CT into this evening * Blustery and very cold tonight with lows between 5 and 15 above zero * Wind chills dropping to between 0 to 10 below zero

A powerful low pressure will move through the Maritimes tonight, and farther from southern New England. This will gradually weaken the pressure gradient, and allow winds to diminish some.
It will still be gusty, so despite a mainly clear sky, not expecting temperatures to bottom out as much as would be possible on a strong radiational cooling night. Should winds slacken faster than current forecast, low temperatures would need to be adjusted even lower due to a relatively fresh snowpack away from the immediate coasts.

Enough wind present to result in wind chills dropping to between 0 and 10 below zero overnight, but should remain above the thresholds for any additional Cold Weather Advisories.

SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/
Key Messages...

* Plenty of sunshine Wed, but with much less wind

Pressure gradient continues to relax Wednesday into Wednesday night. Still gusty but more typical for our region than the high gusts we've seen the past couple of days. Expecting temperatures to tick up a notch during the day, but better radiational cooling conditions should make it even colder Wednesday night.
Below normal temperatures by some 10-15 degrees continue. Still not think we'll need any Cold Weather Advisories, but this will be monitored with later forecasts.

LONG TERM /THURSDAY THROUGH TUESDAY/
Key Messages:

* Thursday's coastal low likely bringing snow to the south coast, Cape, and Islands.

* Calmer weather inbound for the weekend, including a slight warm up for daytime temps.

* High uncertainty surrounding precip for the start of next week.

Thursday Night and Friday...

Models continue to narrow in on the track of the coastal low passing to our south Thursday night into Friday. NAM12km remains the outlier and the furthest northwest; however, most ensembles have ticked slightly further west and north with each subsequent run. With the slight shift in track, the probability of seeing >3" of snow in 24 hours across the far eastern portion of the Cape and Nantucket has increased to 50 to 60 percent, with 30 to 40 percent for the south coast of Rhode Island. The probability for >1" of snow in 24 hours along the I-95 corridor between Providence and Boston remains near 30 to 40 percent. Confidence remains high that the high to our north should keep enough lingering cold air for any precip to remain as snow.

Once the low lifts out Friday, a quick blast of colder air will bring another rounds of gusty northwest winds with overnight temperatures falling into the mid-teens.

Saturday and Sunday...

A weak mid-level ridge and associated surface high pressure on Saturday will allow for a respite from the winter weather. WAA under the ridge looks to allow some warming of surface temperatures, bringing them closer to the climatological norm of upper-30s to low- 40s for the weekend. The relaxed pressure gradient under the ridge should also bring relief from the gusty northwest winds.

Early Next Week...

The start of next week remains very uncertain. Guidance is hinting at a trough sweeping through southern New England, possibly bringing a wintry mix of precipitation sometime Monday into Tuesday; however, model spreads and run-to-run differences are too vast to make any determinations at this time. Stay tuned for more details.

AVIATION /23Z TUESDAY THROUGH SUNDAY/
Forecast Confidence Levels:

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

00Z TAF Update...

Tonight...High Confidence.

VFR. W wind gusts diminish but still expect gusts to persist in the 15 to 30 knot range.

Wednesday and Wednesday Night...High Confidence.

VFR. NW winds diminishing throughout the day, gusts earlier on 20 to 25 kts, but subside to less than 15 kts late afternoon.

KBOS TAF...High Confidence in TAF.

KBDL TAF...High confidence in TAF.

Outlook /Thursday through Sunday/...

Thursday: Mainly VFR, with local MVFR possible. Slight chance SN.

Thursday Night: Mainly VFR, with local MVFR possible. Breezy.
Chance SN.

Friday: VFR. Windy with local gusts up to 30 kt.

Friday Night: VFR. Breezy.

Saturday through Sunday: VFR.

MARINE
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

High Confidence...

* Gale Warnings continue through tonight * Freezing Spray Advisories continue into mid morning Wed

Through Wednesday Night...High Confidence.

Strong low pressure lifting north of the Canadian Maritimes will continue to result in strong cold advection with W wind gusts of 35 to 45 knots into tonight. The pressure gradient should drop enough later tonight into Wednesday so that Small Craft Advisories will be able to gradually replace the Gale Warnings.
Expecting winds and seas to subside enough where no marine headlines should be needed Wednesday Night.

In addition, given the very cold airmass moving across the waters, expect areas of moderate freezing spray into mid morning Wed. Freezing Spray Advisories remain in effect.

Outlook /Thursday through Sunday/...

Thursday: Winds less than 25 kt. Chance of snow. Local visibility 1 nm or less.

Thursday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Chance of snow, chance of freezing spray. Areas of visibility 1 nm or less.

Friday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of freezing spray.

Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Chance of freezing spray.

Saturday through Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Gale Warning until 10 PM EST this evening for ANZ230-236.
Freezing Spray Advisory until 10 AM EST Wednesday for ANZ230>237-250-251-254>256.
Gale Warning until 5 AM EST Wednesday for ANZ231>235-237-250- 251-254.
Gale Warning until 7 AM EST Wednesday for ANZ255-256.