Thunderstorms, A Few Of Which May Be Strong To Severe, Are Expected This Afternoon Into This Evening

For This Afternoon & This Evening: Partly sunny, but with hazy smoky skies are expected throughout this afternoon. The combination of the very humid conditions, temperatures around 85 Degrees, moderate amounts of unstable air and forcing and energy from an approaching frontal system will lead to the development of scattered thunderstorms by early afternoon across Western Mass with these thunderstorms spreading into Central Mass by mid to late afternoon. There is the possibility that a few of the thunderstorms could be on the strong to severe side with wind gusts of 50-60 mph and penny to quarter size hail. I want to emphasize though that I’m not expecting a widespread severe weather event, but instead a couple to a few of the thunderstorms being on the strong to perhaps severe side. In addition to this, the very humid environment will help to wring out a lot of water from the thunderstorms. Because of this, heavy downpours are likely with thunderstorms with at least 1 to 2 inch per hour rainfall rates. Given that rivers and streams are running very high already, any additional rainfall will lead to a flood threat. Also, flash flooding of highways, streets, underpasses and poor drainage areas is likely given the extremely saturated ground conditions. Finally, frequent lightning is likely with any thunderstorms this afternoon and this evening. Thunderstorms, a few of which will be strong to severe, will persist through this evening before ending by midnight. Wednesday: Hazy, smoky skies are expected for Wednesday. There’s the possibility for a couple of showers and thunderstorms around late afternoon across areas south of the Mass Pike. At this point, it appears that areas near and north of the Mass Pike should remain dry during Wednesday. High temperatures will be near 85 Degrees. Winds will be West at 5 to 10 mph. Thursday: Partly sunny skies are expected for Thursday. While a majority of the region should stay dry on Thursday, there’s the possibility for a stray hit or miss shower or thunderstorm during the late afternoon hours. High temperatures will be North at 5 to 10 mph in the morning and Southeast at 5 to 10 mph in the afternoon. Friday: Warm and very humid conditions are expected on Friday. In addition, yet another frontal system will make its way across the region leading to another round of showers and thunderstorms during the day on Friday. Heavy downpours with yet another flash flood threat looks to be the main threat with any thunderstorms. That said, a couple of the storms could be on the strong side with gusty winds and small hail possible. High temperatures will be near 80 Degrees. This Weekend: Saturday looks to feature partly sunny skies and there could be an isolated shower or thunderstorm during the afternoon. I do think that most areas should stay dry though on Saturday. High temperatures will be near 85 Degrees. Sunday looks to be the nicer of the two days this coming weekend with partly sunny skies expected along with somewhat less humid conditions. High temperatures will be near 85 Degrees.

Extremely High & Extremely Serious Flood Threat Today Across Western & Central Mass

The first batch of heavy showers with embedded thunderstorms is now pushing northward into the region. This will be the first of many waves of extremely heavy showers with scattered thunderstorms that are expected today.

I cannot emphasize this enough - the FLASH FLOOD THREAT today is EXTREMELY HIGH. Rain totals of 2 to 3 inches are likely across all of Western and Central Mass.

In addition, rain totals of 4 to 6 inches likely in an area from the lower Pioneer Valley of Western Mass eastward to the Worcester Metro. This includes areas near and south of the Mass Pike from Springfield to Auburn and also includes areas in the western Worcester Hills and across the I-84 corridor, including Sturbridge, Brimfield, Brookfield, Ware, Spencer and Rutland.

These extremely heavy rainfall amounts, which will include hourly rainfall rates of 2 to 3 inches will lead to the potential for very significant amounts of flash flooding of streets, highways, underpasses and areas of poor drainage. Basement flooding is also quite possible for many given the additional rainfall on already extremely saturated ground.

If that wasn't enough, some of the thunderstorms today will likely rotate given the moderate amounts of low-level wind shear that's available. This means there is the potential for a couple of tornadoes across the region, mainly from mid-morning into the early afternoon hours.

Again, I cannot stress enough that the flash flood threat is extremely high today and widespread very significant flooding is likely across the entire area.

Many more updates will be sent out as needed.

There Is A Very Significant Flood Potential On Sunday Across Western & Central Mass

For The Rest Of This Afternoon: A mixture of sunshine and clouds is expected throughout the rest of this afternoon with very warm and humid conditions. In addition, some scattered thunderstorms will be a possible with most of this activity occurring over the Berkshires, the Hilltowns of Western Mass and across the Worcester Hills, especially west of I-190. Temperatures the rest of this afternoon will be near 85 Degrees. Winds will be South at 5 to 10 mph. Late Tonight Through Sunday: I am very concerned that we are looking at a very significant flood event during Sunday across the entire area due to extremely heavy downpours that’ll produce very high rainfall rates. Also, I have some concerns that a few of the thunderstorms may be on the strong to severe side with gusty winds and a couple of tornadoes possible. A frontal boundary is expected to stall over the region by late tonight and during the day on Sunday. This front will interact with a very humid air mass that’ll really be able to wring out the rain from heavy showers and thunderstorms. To make things even worse is that this front will hang over our area for about 18 to 24 hours, which means that there will be a prolonged period of on and off heavy showers and thunderstorms that begin late tonight and continue through the day on Sunday. Current guidance indicates that it’ll only take 1.50 to 2.50 inches of rain in one hour to produce widespread flash flooding across the region. Given that these heavy downpours will be able to easily produce 1 to 3 inches of rain in one hour, I think that flash flood threat across the entire region is extremely high. If that wasn’t enough, there is also the possibility that a few of the thunderstorms could be on the strong to severe side. Very gusty winds look to be the main threat which could lead to isolated tree damage and isolated power outages due to trees easily being pushed over due to the extremely wet ground conditions. Also, a couple of tornadoes are possible are possible as the very humid air mass interacts with moderate amounts of low-level wind shear. To summarize things a little more – Heavy showers with scattered thunderstorms are expected to overspread the entire area around dawn Sunday morning. Widespread heavy showers with scattered thunderstorms are then expected to continue throughout the day on Sunday. The worst part of the heavy showers and thunderstorms look to occur from about 9-10 am until about 3 pm Sunday when extremely heavy downpours will be producing 1 to 3 inches of rain per hour leading to localized flash flooding of streets, highways, underpasses, urban areas and areas of poor drainage.. In addition, a few strong to severe thunderstorms are possible during this time frame, which could produce gusty winds and perhaps a couple of tornadoes. The shower and thunderstorm activity should gradually diminish and end during Sunday evening. All-in-all, Sunday looks like an extremely active day in terms of weather and you should keep checking back for updates. Given the expected flooding, my recommendation is to perhaps cancel or reschedule any plans you may have. If you are planning to be on the roads on Sunday, you may want to reconsider as extremely heavy rainfall rates will lead to flooded roads and extremely poor visibility.