COMMENTARY
Horrible forecast yesterday. No excuse, but the reason for me (and according to NWS discussion, others as well), extremely poor performance by short range guidance in picking up conditions that produce more widespread and persistent rainfall than they were indicating. A forecaster from NWS Boston noted that even the “best performing” piece of guidance was inadequate and far under-forecast the scope of the rainfall. Ouch. I gave a couple of forecasts to people for outdoor events that were less than accurate, to put it nicely, though the events worked out fairly well anyway. Still, not a good feeling when that happens! But, we move forward…
DAYS 1-5 (MAY 19-23)
Since the synoptic conditions haven’t changed all that much today from yesterday, today’s short term forecast is a little less optimistic than I indicated just 24 hours ago. No I don’t think we’re in for a repeat of the rainfall, but an overcast morning with drizzle patches and areas of fog may only improve very slightly, and I can’t rule out pop up showers at any time, as low pressure sits to the south and a fresh feed of Atlantic moisture remains in place. Finally, this begins its exit this evening as high pressure starts to shift in from the southwest and overtake our weather. While some lingering cloudiness is likely to be around Monday, expect a much nicer day overall with fair weather and it turning considerably warmer than the weekend was. This trend will continue for Tuesday and Wednesday as high pressure sits just to our south and puts us in a warm southwesterly air flow. This will give us a preview of summertime with many areas going over 80 for high temps. This, of course, will be a lot harder to achieve closer to the South Coast and over Cape Cod where a southwest wind is a direct ocean wind and the cooler water will have a significant modifying influence. Thursday, the temperature forecast will depend on the speed of an incoming cold front, which will bring the chance of showers and thunderstorms, along with associated cloudiness. Details TBD.
TODAY: Cloudy. Areas of drizzle/fog. Chance of a shower. Highs 56-63, coolest coast. Wind E to SE 5-15 MPH.
TONIGHT: Breaking clouds. Patchy fog. Lows 49-56. Wind SE to S up to 10 MPH.
MONDAY: Variably cloudy South Coast to MA South Shore / more sun elsewhere. Highs 62-69 South Coast to MA South Shore, 70-77 elsewhere. Wind S to SW 5-15 MPH.
MONDAY NIGHT: Partly cloudy. Lows 51-58. Wind S to SW up to 10 MPH.
TUESDAY: Sunny. Highs ranging from near 60 Cape Cod to 81-88 Merrimack Valley, interior MA, southern NH. Wind SW 5-15 MPH.
TUESDAY NIGHT: Clear. Lows 52-59. Wind SW 5-15 MPH.
WEDNESDAY: Sunny. Highs ranging from near 60 Cape Cod to 81-88 Merrimack Valley, east central to central MA, southern NH. Wind SW 10-20 MPH.
WEDNESDAY NIGHT: Partly cloudy. Lows 53-60. Wind SW 5-15 MPH.
THURSDAY: Variably cloudy. Chance of showers and thunderstorms. Highs 68-75, cooler South Coast. Wind SW 10-20 MPH.
DAYS 6-10 (MAY 24-28)
Models may not yet see what turns out to be a rain threat from passing low pressure on May 24, followed by fair weather to at least start and get into the Memorial Day Weekend, with the potential for the next shower threat around Memorial Day itself, unless a slower pattern holds it off til the end of the period. Will monitor the trends. Temps will be typically spring variable.
DAYS 11-15 (MAY 29 – JUNE 2)
Last few days of May look fair, early part of June maybe a shower threat. Progressive pattern – variable temperatures not straying too extremely.