DAYS 1-5 (APRIL 11-15)
When my forecast works out, as my self-expectation is that it should daily, my practice is not to point that out, but I do like to point out things that I missed in a forecast. Yesterday, I was torn on whether or not to put the risk of a pop-up shower from the “heat of the day” (in a relative sense) and ahead of an approaching back-door front. I saw that 2 fairly reliable pieces of short range guidance had forecast these pop ups across central Maine and parts of NH, and I thought about adding a pop up possibility to at least southern NH, but opted to leave it out of the written forecast thinking it was the longest of long shots there. Alas, a decent cluster of moderate to even briefly heavy showers popped up over south central NH and made their way into northeastern MA during the late afternoon and evening Saturday. Certainly not a huge forecast buster, but I’m shore that a few folks’ had a surprise on their evening walks, but at least may have been treated to a rainbow after getting unexpectedly wet. Sometimes a forecaster can worry about putting too much in a day’s forecast, but yesterday when doing a regional forecast it would have been accurate to talk about South Coast low clouds and fog, clouds giving way to sun in the major metro areas, a lot of areas getting well into the 70s, a sea breeze still making an appearance for a while along the eastern shore before giving up again late in the day, and the above-mentioned pop up shower cluster. I didn’t have the last 2 on that list in my forecast, but I should have. Ah well – time to move on! During the early morning hours, the aforementioned back-door cold front did slide across the region and while it was not accompanied by a lot of wind or any precipitation, it did introduce a deck of stratus clouds from the northeast, and a notable temperature drop (Logan Airport, for example, from 58 at 3 a.m. to 49 at 4 a.m., now down a bit more to 48 as of 7 a.m.). The temperature drop was a bit more subtle over inland areas as the front got there a little bit later (some areas are still in the middle to upper 50s as of this blog writing). But by late morning all of the region will be in the marine air mass, generally covered in stratus clouds. There was already a deck of stratus and areas of fog back along the South Coast where the wind was still from the southwest before the front’s arrival since last evening, so they had their marine layer there, just from a different direction, now to mix with the new marine layer from the northeast. While this is going on down here at the surface, another arm of moisture from decaying low pressure to our west is moving into the region from the southwest, and its rain area has struggled to make any significant progress. And while still a decent area of rain, it sits still southwest of New York City early this morning, but will make progress toward and into New England from southwest to northeast, so that by the time it gets into the WHW forecast area during the afternoon and evening it will be in the form of patches of mainly light rain. That’s a shame, honestly, because we could really use a decent rainfall. And even though this low pressure area is going to take 2 1/2 days to pass by our area (center passing to the south of here) and we will be in its circulation, it’s really not going to manage to produce any beneficial rainfall, just lots of clouds, cool temperatures, and some damp weather. We may get a sneaky milder day in about Wednesday as we find ourselves with a small ridge of high pressure sliding across the region and offshore between departing low pressure and the approach of another low from the southwest. By Thursday, we may already be back in the envelope of clouds from this approaching low along with a southeasterly air flow.
TODAY: Cloudy. Areas of fog South Coast mainly during this morning. Areas of fog and drizzle developing East Coast mainly during this afternoon. Chance of light rain mid to late afternoon, favoring areas south and west of Boston. Coastal temperatures fall slightly to 45-52. Inland temperatures 50-57 early fall to 45-52 during the day. Wind NE to E 5-15 MPH.
TONIGHT: Cloudy. Periods of rain possible. Areas of fog and drizzle. Lows 42-49. Wind NE to E 5-15 MPH.
MONDAY: Cloudy. Areas of fog and drizzle. Periods of rain possible. Highs 47-54, coolest coastal areas. Wind E to NE 5-15 MPH.
MONDAY NIGHT: Cloudy. Lows 41-48. Wind NE up to 10 MPH.
TUESDAY: Mostly cloudy. Areas of fog and drizzle possible near the East Coast. Highs 47-54. Wind NE to N 5-15 MPH.
TUESDAY NIGHT: Mostly cloudy. Lows 39-46. Wind N up to 10 MPH.
WEDNESDAY: Partly sunny. Highs 55-62, coolest coastal areas. Wind variable to S up to 10 MPH.
WEDNESDAY NIGHT: Variably cloudy. Patchy fog. Lows 45-52. Wind S to SE up to 10 MPH.
THURSDAY: Mostly cloudy. Highs 52-59, coolest coast. Wind SE 5-15 MPH.
DAYS 6-10 (APRIL 16-20)
Slow eastward progression of large scale pattern. While guidance can lead one astray beyond a few days, the current expectation based on a combo of guidance and pattern anticipation leads to a forecast of cloudy/damp/cool weather for April 16 with and east to northeast wind as low pressure passes to the south, but it remains to be seen if we’ll have any significant rainfall. It may even be cold enough for some mixed precipitation and or snowflakes in parts of the region. This low should exit with a drier/cool northerly air flow by April 17. As high pressure ridging nudges eastward we should end up milder/dry for April 18-19 before the next low from the west brings at least clouds back by the end of the period.
DAYS 11-15 (APRIL 21-25)
Still not putting much faith in guidance beyond general pattern ideas out this far into the future. Early idea: Dry start, then some wet weather chances. No temperature extremes.