Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
744 FXUS61 KBOX 010522 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 122 AM EDT Wed May 1 2024 .SYNOPSIS... An approaching cold front will bring another round of showers to the region tonight with a few embedded thunderstorms possible across interior Massachusetts and Connecticut. Considerable cloudiness persists on Wednesday, but peeks of sunshine too, especially in the afternoon. Unsettled mid to late this week due to a backdoor cold front nearby. This could bring spotty showers and keep us a bit cooler, but there is a significant amount of uncertainty with the fronts location. Better shot for more widespread showers late Saturday into Sunday as a frontal system slides through. && .NEAR TERM /THROUGH TODAY/... 11PM Update Forecast remains on track at this hour and no changes are needed to the near-term forecast. See previous discussion for more details. Previous Discussion... An approaching shortwave/cold front coupled with diurnal heating was allowing showers and embedded thunderstorms to develop this afternoon across NY State & PA. As this shortwave/cold front moves east, expect showers to enter western MA & CT after 7-8 pm this evening. The environment across our region is not as favorable though given the marine layer in place. So while we may still a rumble or two of thunder across interior MA & CT with a few brief downpours, expect a weakening trend. So will just stick with showers across eastern MA/RI where the activity will not enter the region after 10-11 pm. The bulk of the showers should come to an end toward morning, but a few showers may linger through daybreak especially towards the southeast New England coast. Overnight low temps should mainly be in the 40s to near 50 with some patchy fog possible. && .SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/... Key Points... * Considerable cloudiness Wed but a few peeks of sunshine too * Highs Wed...50s coast, 60s inland & near 70 in parts of CT Details... Wednesday... A few lingering showers possible early Wednesday morning across southeast New England, but departing shortwave/front will bring a quick end to this activity by mid to late morning. Otherwise, a wave of low pressure passing to our south coupled with high pressure across eastern Canada will generate a continued moist NE low level flow. We expect a fair amount of cloudiness around but a few peeks of sunshine especially in the afternoon. Generally dry weather will prevail for most of Wednesday with the lack of synoptic scale forcing, but a few spot showers can not be ruled out. Given the onshore flow, temperatures will vary considerably. Highs should be held in the 50s along the immediate coast, to 60s further inland, while areas near the lower CT River Valley will top off around 70. These temperatures may need to be fine tuned depending on the amount of solar insolation and onshore flow. Wednesday night... A northern stream shortwave will be dropping southward from Quebec into northern New England Wed night. The better dynamics/forcing will remain to our north where we expect most of the precipitation. However, we may see a few showers develop mainly across our northern zones toward daybreak Thu. Overnight low temps should mainly be in the 40s. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Highlights: * Good amount of uncertainty during this portion of the forecast with timing and exact location of showers. * Backdoor cold front on Friday. This could bring spotty showers and keep us a bit cooler, but there is a significant amount of uncertainty with the fronts location. * Unsettled with rain chances continuing late this weekend as a front moves across the region. Have the greatest confidence in the forecast into the first part of this weekend. Then there are significant difference in the larger synoptic pattern features into the middle of next week. Expecting a fairly active pattern through most of next week. This is leading to uncertainty, especially with the timing and location of these showers. That is not unusual for this time of year. Some signs that a high pressure ridge off the east coast of MA. How strong this high pressure will be is a factor to monitor. Should this ridge be stronger, then we may get through most of this weekend dry. More likely to see showers some time late Saturday into Sunday. Trending drier early next week, but again uncertainty regarding the timing details. Thinking temperatures should be near to slightly below normal into this weekend. Odds favor a switch to above normal temperatures early next week. && .AVIATION /05Z WEDNESDAY THROUGH SUNDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z TAF Update Through 12Z...Moderate Confidence -SHRA/-RA gradually tapers off from the terminals at and west of ORH by 07-08Z. MVFR/borderline IFR ceilings persist through 12Z across southern New England. Showers continue through about 10-11Z for th eastern terminals with a few stray showers possible thereafter. Light east/northeast winds. Today...Moderate Confidence. Any remaining showers depart the eastern terminals by 12-13Z. We should see cloud bases slowly lift into the early afternoon hours with VFR ceilings likely by 21Z or perhaps earlier. NE winds 5 to 10 knots. Wednesday night...High Confidence. MVFR/IFR conditions return overnight with a spot shower possible, but mainly dry weather expected. Easterly winds gradually become southeasterly and eventually southerly overnight with light speeds around 5 knots. Tomorrow...High confidence in trends, moderate confidence in timing. IFR/MVFR ceilings early will gradually lift to VFR levels by about noon time. Winds look to be steady out of the south/southwest for the first half of the day, but winds may shift counter-clockwise by later afternoon as a low-pressure circulation may be traversing over the region with a few showers. KBOS TAF...Moderate Confidence in TAF. Showers should taper off from the terminal by 09-10Z but could possibly linger as late as 12-13Z. KBDL TAF...Moderate Confidence in TAF. Outlook /Thursday Night through Sunday/... Thursday: Mainly VFR, with local MVFR possible. Breezy. Slight chance SHRA. Thursday Night: Mainly VFR, with local IFR possible. Friday: Mainly VFR, with areas MVFR possible. Friday Night: Mainly VFR, with local MVFR possible. Saturday through Saturday Night: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Sunday: Mainly VFR, with local MVFR possible. Chance SHRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Wednesday night...High Confidence. A weak pressure gradient will keep winds/seas below Small Craft Advisory thresholds through Wed night. E winds shift to the NE at 5 to 15 knots tonight and Wed, but then will become light S tonight. Outlook /Thursday Night through Sunday/... Thursday: Winds less than 25 kt. Chance of rain showers. Thursday Night: Winds less than 25 kt. Slight chance of rain showers. Friday through Friday Night: Winds less than 25 kt. Saturday through Saturday Night: Winds less than 25 kt. Slight chance of rain showers. Sunday: Winds less than 25 kt. Chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Belk/Frank NEAR TERM...Belk/RM SHORT TERM...Frank LONG TERM...Belk AVIATION...RM/JWD MARINE...Belk/Frank