Significant Weather Blog: Thursday, May 28, 2026 5 PM

Rain and Chilly Late Friday and Saturday Followed by a Round of Showers Monday and Tuesday

The weather for this weekend and even into early next week looks significant enough to warrant an update. Rain/showers and a period of gusty winds are two items worthy of a closer look. Have retained the hurricane season outlook issued earlier in the week following this week’s weather update. Before looking ahead, let’s take a quick look at what has happened this afternoon (Thursday afternoon). This afternoon has been a good example of convective showers induced by cold temperatures aloft with some assistance from a passing upper trough. Those cold temperatures aloft result in a steepening lapse rate (rate of temperature change with height) as sunshine warms the ground and adjacent lower atmosphere. This causes the air mass to become unstable and enables rising pockets of air to keep rising high enough to condense moisture in the air and ultimately shafts of precipitation. Next Monday and Tuesday afternoons will probably demonstrate more examples of this type of instability and associated convective showers. Rain and Chilly Late Friday Night and Saturday An anomalously (for this time of year) closed upper low (or cutoff trough as meteorologists will often say) will swing south from a broader upper trough centered over the Canadian Maritimes and cross southern New England late Friday night and Saturday. This closed upper low will help generate a significant surface low pressure center just off our coast by Saturday morning. It will also bring another exceptionally cold pool of air aloft across southern New England as well on Saturday. The surface low pressure area will likely generate rain bands across central and eastern sections, possibly enhanced over a portion of eastern MA due to a coastal front. A coastal front typically forms as ENE winds over the ocean encounter greater friction over land and cause both a decrease in speed and shift in direction to be more from the N (versus ENE). This results in both speed and directional convergence of moist air, which in turn induces a band of stronger uplift and heavier precipitation. We tend to witness this phenomenon more often during the winter in connection with coastal nor’easters. In addition, the cold pool of air aloft (even colder than this afternoon) will likely induce scattered convectively driven showers further west (western MA and CT), where possibly a little surface heating may occur, although the timing of the coldest air aloft is in the morning and timed before maximum heating of the lower atmosphere. It’s possible one or two of the heavier showers over the Berkshires and northwest CT could contain small hail given low freezing levels. It will be unusually chilly for late May on Saturday with temperatures struggling to get above the mid to upper 40s across the higher terrain and low 50s across the coastal plain. It is even not out of the realm of possibility that some wet snowflakes may mix with the rain over the higher elevations of the Worcester Hills and northern Berkshires given the anomalously cold air mass and low freezing levels. Potential for Strong Winds Late Friday Night and Saturday Perhaps of greater significance is the potential for a period of gusty north winds over land and northeast gale gusts over the coastal waters late Friday night and Saturday. Wind gusts of 45 to 50 mph along coastal areas and 40 to 45 mph further inland may down branches and weakened trees. The fact that trees are now fully leafed out increases the risk for damage and scattered power outages. It looks as though the strongest winds may occur Saturday morning. Over the coastal waters, NE 35 to 40 knot gusts may occur and cause very hazardous conditions for small craft. Waves up to around 15 feet are possible during Saturday across the eastern exposed coastal waters (including Massachusetts Bay). Boaters should carefully monitor the latest forecasts from the National Weather Service for Saturday. This is of greater concern as we are now starting to head into the recreational boating season. Early Next Week Still another sharp upper trough that may close off will likely pass southward across or very near southern New England on Monday and linger at least until Tuesday of next week. Although not as much of a surface low pressure development is expected at this time, this trough will likely produce another pool of unusually cold air aloft on Monday. This time there could be more in way of surface heating and greater instability to produce numerous showers and possibly even a few thunderstorms. A few of the heavier showers and thunderstorms Monday afternoon could produce small hail (i.e., pea size). Since the cold pool aloft may linger into/through Tuesday, we could see a repeat performance on Tuesday. Hurricane Season Outlook The hurricane season for the Atlantic Basin begins June 1, although most hurricane activity usually occurs August through early October. NOAA’s Climate Prediction Center (with input from other NOAA offices) issued its 2026 hurricane season outlook on May 21. More or less in concert with the hurricane seasonal outlooks from other entities, the NOAA prediction indicates hurricane activity this coming season to likely be below normal. This is in large part a consequence of an expected El Nino condition that will be strengthening during the period of the 2026 hurricane season. In fact, there are indications that the coming El Nino could be significantly stronger than average. An El Nino event typically results in warmer than average water temperatures in the equatorial eastern Pacific Ocean and in turn greater convection (i.e., showers and thunderstorms) in that region. The convection further acts to strengthen the subtropical jet aloft, which in turn results in relatively high vertical wind shear in the main development region for hurricanes in the tropical Atlantic and Caribbean Sea. That high vertical wind shear tends to disrupt hurricane formation by shearing incipient storms apart. There are other factors that help determine hurricane development in the tropical Atlantic. These include sea surface temperatures. Warmer than average sea surface temperatures may counteract to some extent the inhibiting influence of hurricane development by El Nino. We have seen this play out in prior years. Another factor can be the strength and positioning of the West African monsoon. The 2026 West African monsoon may be displaced further north and inland than average. This could result in disturbances passing off the African west coast to entrain dry air, which would tend to inhibit development. Still another factor could be the phase of the Madden Julian Oscillation (or MJO) and as to whether it’s inducing broad upward motion or broad downward motion. This is something that’s fairly hard to predict far in advance. We have also seen in some years the prevalence of Saharian dust acting to suppress hurricane formation, but this, too, is difficult to predict much ahead of time. And then, there’s still the possibility of tropical cyclones forming along the periphery or outside of the main development region of the tropical Atlantic and Caribbean Sea in regions of less vertical wind shear. Given all of these factors, it looks like a below normal level of hurricane activity is favored this year for the Atlantic basin. The NOAA outlook calls for a 55% chance of a below normal season, a 35% chance of a near normal season, and only a 10% chance of an above normal season. This equates to a forecast of 8 to 14 named storms (winds 39 mph or higher), 3 to 6 hurricanes (winds 74 mph or higher), and 1 to 3 major hurricanes (category 3 or greater or winds of 111 mph or higher). Average storm totals for a hurricane season are 14 named storms, 7 hurricanes, and 3 major hurricanes. Yet, there remains some degree of uncertainty (e.g. influence of warmer than average sea surface temperatures, the specific characteristics of this year’s west African monsoon, the shorter-term weather pattern when a tropical disturbance may be trying to develop, etc.). Keep in mind that just one landfalling major hurricane along a vulnerable portion of the U.S. coastline could result in a very high impact event and result in this season being remembered as high impact even if the overall level of hurricane activity is low. Hurricane Andrew, a devastating category 5 storm that hit south Forida in 1992, is such an example. Andrew was one of only ten named storms and the only major hurricane in that season. Also, the impact of a tropical cyclone is not necessarily correlated to wind intensity. For example, Hurricane Sandy was a category 1 hurricane undergoing extratropical transition but had a very significant impact from its storm surge given its size and trajectory. There have also been very high impacts from tropical storms (winds below hurricane force) due to excessive rainfall rates and fresh water flooding. For example, Tropical Storm Dianne in 1955 caused devastating stream and river flooding throughout much of southern New England. Thus, all people who live in an area that could be impacted by the storm surge, wind, and/or freshwater flooding from a hurricane should make sure they have a preparedness plan in place. The cliché of “all it takes is one” applies. Will continue to monitor the development of the expected El Nino. Although other factors often mask the influence of El Nino on New England weather, El Nino has often had major impacts for other parts of this country as well as other locations throughout the world. Will take a closer look at El Nino and its potential impact on the 2026-2027 winter in a future blog. Next Message The next message will probably be the weekly significant weather outlook to be issued Monday June 1. About this Blog and Disclaimer The National Weather Service monitors the weather 24/7 and updates forecasts, watches, and warnings as necessary. For most of southern New England, refer to your local Weather Forecast Office for the latest forecast/warning information at weather.gov/box. For information from other Weather Forecast Offices, go to weather.gov and click on the location of interest on the map. The frequency of this blog will depend upon the nature of the weather threat and availability of the author. Thus, for the latest information on weather forecasts and warnings, refer to the National Weather Service, which monitors and forecasts the weather 24/7. Blue Hill Observatory and Science Center (BHOSC) The BHOSC maintains a continuous daily observation record that dates from February 1, 1885 without interruption and provides educational information on weather and climate to area students and the community at large. Your support of BHOSC is much appreciated and enables this nonprofit organization to maintain the long-term climate record at the Blue Hill Observatory (longest continuous record in North America) and provide valuable educational resources on weather and climate via outreach to schools, site visits/tours, webinars, and conferences. For more information on the Blue Hill Observatory and Science Center, explore bluehill.org. Message issued May 28, 2026 by: Bob Thompson Retired National Weather Service Meteorologist Blue Hill Observatory and Science Center Board member