Significant Weather Blog: Wednesday, March 4, 2026 7 PM
Wintry Mix Thursday Evening/Night into Friday Morning
Low level cold air intruding southward from Canada and northern New England will set the stage for precipitation to change from rain to freezing rain/sleet and then possibly to snow Thursday night into Friday morning for a large part of southern New England. This scenario could cause especially hazardous travel conditions.
One usually needs to be wary of strong surface high pressure areas over Quebec during the cool season as we experienced Tuesday afternoon/evening and will likely experience Thursday night into Friday morning. A quasi-stationary front will lie near the New England south coast Thursday and Friday. A wave of low pressure, relatively weak but containing at least a moderate amount of moisture, will cause precipitation to spread across southern New England Thursday afternoon as warm, moist air overrides colder air near the surface. Initially, the precipitation should be in the form of rain but colder low-level air intruding south from strong high pressure over Quebec is expected to cause rain to change to freezing rain and then sleet and then possibly snow as that layer of cold air deepens and moves south. This is mainly a concern in MA northwest of I-95, across northern RI (especially north of I-29), and northern CT. Along the coastal plain south of Boston and the CT and RI south coasts, the precipitation will probably stay mostly in the form of rain with perhaps some sleet or wet snow mixed in early to mid-Friday morning. The precipitation should end Friday mid to late morning, although there is a risk of some drizzle or freezing drizzle lingering into the afternoon.
Timing: There is considerable uncertainty in timing and amounts. Rain may change to freezing rain or sleet across northern MA as early as late afternoon and impact the Thursday evening rush hour. There is uncertainty how quickly the mixed precipitation spreads south Thursday evening and just how far south it travels. Based on prior experience with this type of synoptic weather pattern, am inclined to err on the side of those model projections that take the subfreezing air further south. Travel may become very slippery as far south as the Mass Pike (I-90) corridor during Thursday evening.
Amounts: As far as amounts, anticipate the potential for .1 to .2 inches of ice accretion along and north of the Mass Pike (I-90) in eastern/central MA and along/north of I-84 in CT and throughout western MA. There may be pockets of .2 to .3 inches of ice accretion over the higher terrain of central/western MA and northern CT. Lesser ice accretion is expected further south. As far as snow, 1 to 2 inches may fall along and north of the Mass Pike except possibly 2 to 4 inches over north central and northeast MA near the NH border. There is much uncertainty, however, in snowfall accumulations for an event that is only about 24 hours away! Some model projections depict very little snow anywhere in southern New England and others (such as the GFS) show as much as 4 to 6 inches falling in northeast MA.
Impacts: The primary impact is expected to be hazardous travel. The anticipated scenario of rain to freezing rain to sleet to snow can be especially hazardous for travel even on roads that are typically well-treated. Thus, extra caution is advised for any travel Thursday evening through Friday morning. A secondary impact could be some scattered tree/powerline damage from ice accretion with the greatest risk being over the higher terrain of central and western MA and northern CT. We usually start to see some tree damage and powerline outages once ice accretion exceeds a quarter of an inch (with more widespread tree/powerline damage when ice accretion reaches a half inch).
Next Message
Will review this situation Thursday morning and update this message if necessary.
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A blog is issued when there is a potential risk of hazardous weather to southern New England and serves to provide background information regarding the significant weather with somewhat of an educational slant. In the case of hurricanes, the author will attempt to issue a message when any portion of the United States coastline may be seriously impacted. It’s intended to complement and not serve as an alternative to official forecasts issued by the National Weather Service. Readers are urged to check National Weather Service forecasts and warnings for the most timely and updated weather information. This weather message is solely produced by the listed author and does not constitute an official product of the Blue Hill Observatory and Science Center (BHOSC).
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Message issued March 4, 2026 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Board member
