Heavy Rain In Far Western Mass This Afternoon Will Spread Across The Entire Area Late Tonight & Mon.

Heavy rain with embedded thunderstorms are currently pushing due north into the Berkshires as of the time of this writing. This heavy rain is likely to be occurring across all of far Western Mass (areas west of I-91) by about 1:30-2 pm. Rainfall totals this afternoon across far Western Mass are likely to amount to at least 1 to 2 inches.

Those of you that either live in far Western Mass or are traveling that way, be aware that flooding of highways, roads and areas of poor drainage is likely this afternoon. Also, poor visibility in heavy rain will make travel very challenging.

Further East, the coverage of the showers and thunderstorms are expected to be very scattered this afternoon and during the first half of tonight across the rest of Western Mass and all of Central Mass. That said, any heavy showers or thunderstorms will be capable of producing torrential downpours that will lead to the potential for flooding of streets, highways and poor drainage areas.

Extremely heavy rain is still expected across the entire area beginning well after midnight tonight and continuing through all of Monday. Flash flooding is likely across the entire area and is something that's going to have to be monitored very closely.

In addition, scattered embedded thunderstorms are expected during Monday across the entire area and some of these storms may be on the strong side. Main threat will be very gusty winds and frequent lightning. That said, the low-level wind shear is likely to be quite robust during Monday due to a surface low pressure system lifting across the region. Because of this, a very isolated tornado or two is a very slight possibility. I want to emphasize though that the tornado threat is extremely low, but the environment will be somewhat favorable for thunderstorms to rotate. So this is something else that will be monitored very closely.

Rainfall totals through Monday evening are expected to range from 1.50 inches to 2.50 inches with locally higher amounts across Central Mass to 2.50 inches to 4 inches with locally higher amounts across Western Mass. Upwards of 6 inches of rain is quite possible across the Berkshires and this is the area I'm extremely concerned about in terms of flash flooding.

Periods Of Heavy Rain Sunday Night & Monday Will Lead To A Flash Flood Threat

For The Rest Of This Afternoon: Widely scattered showers and thunderstorms are expected to continue throughout the rest of this afternoon across mainly Western Mass. In fact, the greatest coverage of showers and thunderstorms is expected to be across the Berkshires where local rainfall amounts of between one half of an inch and one inch is possible. Other than this, it will be very warm and very humid throughout the rest of this afternoon with temperatures between 85 and 90 Degrees. Tonight: Any leftover showers and thunderstorms will weaken and dissipate shortly after sunset this evening. Other than that, low clouds and areas of fog will develop across the region by after midnight in the very humid air mass. Low temperatures will be between 65 and 70 Degrees. Sunday: Another warm and very humid day is expected on Sunday. In addition, a frontal boundary now located over the Ohio Valley will slowly make its way eastward towards our area. Most of the energy with this front will remain to our west during Sunday. This all means that some widely scattered showers and thunderstorms can be expected during Sunday afternoon. Any heavy showers or thunderstorms will be capable of producing some torrential downpours, but the really heavy rain is expected to hold off until Sunday night and Monday. High temperatures will be between 80 and 85 Degrees. Heavy Rain Late Sunday Night Through Monday Will Result In The Threat For Flash Flooding: That frontal boundary will push its way into southern New England during Sunday night and Monday. At the same time this is happening, an area of low pressure will slowly move along this front. The combination of a very humid air mass, as well as energy and forcing from both the front and the low pressure system will help to produce the very real threat for heavy rain across Western and Central Mass during Sunday night and Monday. This heavy rain will fall on a very saturated region leading to the threat for flash flooding. In addition to the flash flood threat, latest forecast guidance continues to point to some of the rivers and streams across the region to flood during the first half of next week. This flood threat is something that I’m watching extremely closely. For Sunday night, I think that we’ll see scattered showers and thunderstorms during the evening that will become widespread late at night. Heavy downpours are likely with any thunderstorms late at night Sunday night. Low temperatures Sunday night will be between 65 and 70 Degrees. Monday looks very wet with widespread showers and thunderstorms throughout the day. Frequent rounds of heavy rain is likely during the day on Monday which could lead to flash flooding across the region. If that wasn’t enough, there’s also expected to be the possibility for some strong thunderstorms from late morning through the afternoon hours on Monday. Primary threat from any strong storms look to be very gusty winds. High temperatures Monday will be between 75 and 80 Degrees. Total rainfall amounts from Sunday night through Monday are expected to range from 1.50 inches to 2.50 inches with locally higher amounts across Central Mass to 2.50 to 4 inches with locally higher amounts across Western Mass. Upwards of 5 inches of total rainfall is possible across the Berkshires. Tuesday: The coverage of shower and thunderstorm activity should be much less for Tuesday with generally partly sunny skies expected. At this point, I think that some scattered hit or miss shower and thunderstorm activity is possible for Tuesday afternoon. High temperatures will be between 80 and 85 Degrees. Wednesday Through Friday: The rain forest type weather is likely to continue through all of next week across the area with no reprieve from the very humid conditions. Wednesday looks like it’ll feature partly sunny skies with high temperatures between 85 and 90 Degrees. Thursday is expected to be partly sunny with high temperatures between 85 and 90 Degrees. Yet another frontal system is expected to push across the region with a wave of low pressure moving along this front late Thursday night and Friday. This means another round of heavy showers and thunderstorms with heavy downpours and a threat for more flash flooding could be in the offing for the period from late Thursday night through Friday.

Heavy Downpours Sunday Night & Monday Could Lead To The Threat For Flash Flooding

Tonight: Any leftover showers and thunderstorms over far Western Mass should dissipate shortly after sunset. Other than this, dry weather is expected for tonight with areas of low clouds and fog developing after midnight. Low temperatures will be between 65 and 70 Degrees. Winds will be Southwest at 5 to 10 mph. Saturday: The atmosphere should be a little more unstable during Saturday and because of this, I think we’ll probably see a few very isolated thunderstorms during the afternoon. Since there will be limited amounts of forcing, I think most areas should remain dry and any thunderstorms will be extremely hit or miss. High temperatures Saturday will be between 85 and 90 Degrees. Winds will be South at 5 to 10 mph. Sunday Through Monday: An upper level trough of low pressure is expected to be positioned just to our west. The southerly wind flow on the eastern side of this trough will push very humid air northward into our area during Sunday, Sunday night and Monday. At the same time this is occurring, an area of low pressure is forecast to head northward from the Mid-Atlantic states and pass either near or right over Southern New England on Sunday night and Monday. I think that there is an increasing threat for a heavy rain and potential flash flood situation across Western and Central Mass on Sunday night and Monday due to slow moving heavy showers and thunderstorms that produce copious amounts of rainfall. In addition, forecast guidance of the rivers and streams across the region point to the possibility that at least a few of them could approach flood stage by Monday night and Tuesday and this is something that’ll need to be watched. For now, I think that Sunday will be quite humid with some scattered showers and thunderstorms during the afternoon, especially over Western Mass. High temperatures will be between 80 and 85 Degrees. Widespread showers and scattered thunderstorms with heavy downpours are expected on Sunday night across the entire area. Low temperatures will be between 65 and 70 Degrees. Widespread showers and scattered thunderstorms with heavy downpours is likely to continue through Monday across the entire area. High temperatures Monday will be between 75 and 80 Degrees. Total rainfall amounts from Sunday afternoon through Sunday night and Monday may range from 1 to 2 inches with locally higher amounts across Central Mass to 2 to 3 inches with locally higher amounts across Western Mass. Upwards of 4 or more inches of total rainfall is possible across the Berkshires. Tuesday: The coverage of shower and thunderstorm activity should be much less for Tuesday with generally partly sunny skies expected. At this point, I think that some scattered hit or miss shower and thunderstorm activity is possible for Tuesday afternoon. High temperatures will be between 80 and 85 Degrees. Wednesday Through Friday: The rain forest type weather is likely to continue through all of next week across the area with no reprieve from the very humid conditions. Wednesday looks like it’ll feature partly sunny skies with high temperatures between 85 and 90 Degrees. Yet another frontal system may pass across the region with a wave of low pressure moving along the front late Thursday night and Friday. This means another round of heavy showers and thunderstorms with heavy downpours and a threat for more flash flooding could be in the offing for late Thursday night, Friday and Friday night.