Cape Elizabeth ME to Merrimack River MA Marine Forecast
|This Afternoon...Sw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft.|
|Tonight...W Winds 15 To 25 Kt, Becoming Nw 20 To 25 Kt After Midnight. Gusts Up To 35 Kt. Seas 4 To 6 Ft.|
|Sat...N Winds 15 To 25 Kt With Gusts Up To 35 Kt. Seas 4 To 6 Ft.|
|Sat Night...Ne Winds 10 To 20 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft.|
|Sun...Ne Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft.|
|Sun Night...Ne Winds 15 To 25 Kt, Becoming 20 To 25 Kt After Midnight. Gusts Up To 35 Kt. Seas 4 To 7 Ft, Building To 6 To 9 Ft After Midnight. A Chance Of Rain After Midnight.|
|Mon...Ne Winds 20 To 30 Kt With Gusts Up To 40 Kt. Seas 9 To 12 Ft. Rain Likely. Vsby 1 To 3 Nm.|
|Mon Night...N Winds 15 To 25 Kt With Gusts Up To 35 Kt. Seas 9 To 12 Ft. Rain Likely. Vsby 1 To 3 Nm.|
|Tue...W Winds 5 To 15 Kt With Gusts Up To 20 Kt. Seas 6 To 9 Ft. A Chance Of Rain. Vsby 1 To 3 Nm.|
|Tue Night...Nw Winds 5 To 10 Kt. Seas 4 To 6 Ft.|
Area Forecast Discussion|
...UPDATED National Weather Service Gray ME
1037am EST Fri Nov 15 2019
Today will be warmer than recent days, but a strong cold front sweeps across the region this evening and tonight with a dramatic drop temperatures to follow. Snow showers and squalls are expected with the cold frontal, mainly in the mountains. Below normal temperatures stick around through the weekend with a warming trend and a return to active weather early next week with mixed precipitation possible Monday into Tuesday.
Near Term - Until 6pm This Evening
Update...Minor changes to reflect latest observational trends. Forecast to Arctic front and snow squalls looks on track. Timing on hi-res model guidance is consistent with satellite observations and time of arrival tools. That would place first squalls in Nrn zones around 7 pm.
Previously... Warm southwesterly flow this morning allows temperatures to warm to values not seen around these parts for several days. Look for highs to reach into the 30s across the north, 40s south. The NH seacoast could make a run at 50 degrees this afternoon with a dry slot leading to mostly sunny skies over the coastal plain.
The warmth comes in response to increasing southwest flow ahead of an approaching trough aloft, positioned over ON/QC this morning. Increasing mass/pressure gradient today will lead to steadier flow on the order of 10-15 kts over the lowlands with gusts 20-25 kts. The cold front steadily crosses the Great Lakes region this morning as a neutral-tilt upper level trough crosses west to east. Late this afternoon, as the front crosses into the St Lawrence basin, snow showers start to cross over from Quebec. Should precipitation arrive sooner some of the snow may land as rain over the northern valleys.
Short Term - 6pm This Evening Through 6pm Saturday
This evening, a jet stream rounds the base of the trough aloft, amplifying the wave as it does so, and quickly pushing the cold front at the surface through the forecast area. At this time, hires model guidance places the cold front at the Whites/higher terrain by about 7 PM, moving entirely offshore by midnight. While the front itself will be by and large moisture starved, strong cold advection in the mid-levels offers a much more favorable environment for snow showers/squalls and gusty winds in an autoconvective environment. As has been stressed in previous forecast discussions, the ingredients for dangerous snow squalls are there in the post frontal environment - a bit of CAPE, lingering low level moisture, and steep lapse rates aloft.
For frontal timing, chose to rely primarily on NAMnest, although not exclusively. In general, shower/squall coverage behind the front dramatically declines after crossing the mountains. But, a period of strong upslope winds will tend to eke out all available moisture for an additional couple hours after frontal passage across the mountains and areas north. Expect a cool, breezy, and mostly sunny Saturday morning with only scattered clouds remaining over the north. Stuck close to raw model guidance for temperature trends with frontal passage and overnight cold advection, yielding lows in the single digits north and in the teens south.
Strong high pressure quickly builds in from the West Saturday with mostly clear skies and decreasing winds. In spite of plenty of sun, continued cold advection will limit temperatures to the teens north, and within a few degrees of 30 south.
Long Term - Saturday Night Through Thursday
Active pattern in the cards during the long term period as a parade of rather high amplitude short wave troughs eject out of the western states and move eastward. The first of which appears to affect our weather Monday into Tuesday as one or two southern stream troughs move northward after making a turn in the southeastern states. The models are in loose agreement with the eventual overall picture with chances for mixed precipitation, but details like timing and ptype are going to be hard to pin down for awhile as the amplitude, track, and interaction of the approaching short wave troughs gets better resolved.
Took an ensemble approach with temps at the SFC and aloft, with most weight given to the 00z ECMWF (European Centre for Medium-Range Weather Forecasts) as it has shown good run to run consistency. The upshot is that the main chance of steady precipitation should be late Monday into Tuesday with a mixed bag quite possible. However, this is certainly subject to change as ensemble members offer very different takes on timing which isn't all that surprising given the rather complex short wave trough configuration. With the aforementioned blend in mind, with most weight on the ECMWF, weather grids show a mixed bag of precipitation, with freezing rain, sleet, some snow, and rain all possible between Monday and Tuesday. The forecast will certainly have to be refined to be more specific with with time.
Thereafter, most members of the 00z model suite continue the parade of short wave troughs, which means a potentially stormy pattern upcoming with colder than normal temperatures expected.
Upgraded the Gale Watch and SCAs (Small Craft Advisories) to a Gale Warning over the waters and Penobscot Bay with gusty NW winds expected in the wake of a crossing cold front later this evening and tonight. Only exception is Casco Bay where SCAs (Small Craft Advisories) for wind was maintained for the same time period tonight. Tomorrow, high pressure quickly builds in with winds decreasing and taking on a more northerly clip.
Long Term...Gales will be possible Monday into Monday night in association with coastal low pressure.
NOAA Gray/Portland ME Office - Watches - Warnings - Advisories
Small Craft Advisory from 10pm this evening to 7am EST Saturday for ANZ153. Gale Warning from 10pm this evening to 7am EST Saturday for ANZ150>152-154.