Blackstone Valley Weather Service: Heavy Rain Likely Tomorrow....For Some

Like a good snowstorm the cutoff between beneficial rain and nah will be a matter of miles tomorrow. The National Weather Service has issued a flood watch for SE MA, RI and CT. That doesn't include Worcester County has the bulk of the moisture will be closer to the South Coast.

NWS Boston Headlines

Here is the current radar for the entire Northeast.

NWS Northeast Regional Radar Loop

The activity in Northern New England is from an approaching cold front. A surface low has formed in the Mid Atlantic. This will track Northeast and link up with the northern front that will stall near the South Coast.

WPC Surface Analysis 2 PM

Now extremely tropical moisture will be in place. Our wind is out the Southwest. On this water vapor satellite loop (which tracks the amount of moisture in the atmosphere) track the flow from the Atlantic and Gulf of Mexico into the Eastern United States.

NOAA GOES_East Water Vapor Satellite Loop

Showers will break out ahead of the cold front later this evening in Western MA/CT and work east after midnight. By daybreak areas south of the Pike will be raining. Now does the rain make it all the way to the Mass Pike? That is questionable. Sometimes these systems blow up in the Mid Atlantic and the stronger low pulls the available moisture from Southern New England into itself. Some models show this. Here is the forecast surface chart for tomorrow at 8 AM

WPC Surface Forecast 8 AM Friday

Here is one simulated radar image (there are many that all show slightly different outcomes)

19z HRRR Parallel Simulated Radar 9 AM (Image Weatherbell)

Notice the brighter colors over Long Island? There could be some stronger thunderstorms near the center of this low. Severe weather parameters are quite high for the South Coast/Cape and Islands. A brief tornado or waterspout is possible. We really need this rain. According to the Whitinsville Water Company we are now nearly 13" below normal dating back to January 2015. June and July have been bone dry as well with less than 4" of rain combined. That has lead to a Drought Watch.

Drought Watch Issued
A drought watch has been issued for out region as of July 1. Most towns around us already had issued water bans but until today Sutton and Northbridge had not.

MWRA Drought Status

As a result the Whitinsville Water Company has issued a Stage 1 Water Restriction. From the press release
The water restrictions will be effective Friday July 29th. A Stage 1 Water Restriction entails a voluntary restriction on all non-essential outdoor water to odd/even days. This means that if your house number is an even number (ends in 0,2,4,6,or 8) , we would ask that you only water on even dates either before 9am or after 5pm on that day. And if you house number is an odd number (ends in 1,3,5,7 or 9), we would ask that you only water on odd dates either before 9am or after 5pm on that day. If you have a shared irrigation system, we ask that you set the timer to run only on even days either before 9am or after 5pm.

Examples of “Nonessential” outdoor water uses include:

irrigation of lawns via sprinklers or automatic irrigation systems;
washing of vehicles, except in a commercial car wash or as necessary for operator safety; and
washing of exterior building surfaces, parking lots, driveways or sidewalks, except as necessary to apply surface treatments such as paint, preservatives, stucco, pavement or cement.

Examples of water uses that may be allowed:

irrigation to establish a new lawn and new plantings during the months of May and September;
irrigation of public parks and recreational fields by means of automatic sprinklers outside the hours of 9 a.m. to 5 p.m.; and
irrigation of lawns, gardens, flowers and ornamental plants by means of a hand-held hose.

Examples of water uses NOT subject to mandatory restrictions:

for health and safety reasons;
by regulation;
for the production of food and fiber;
for the maintenance of livestock; or
to meet the core functions of a business (for example, irrigation by golf courses as necessary to maintain tees, greens, and limited fairway watering, or irrigation by plant nurseries as necessary to maintain stock).

The reason for watering before 9 AM and after 5 PM is simply because the process of evaporation in the peak heating hours does more damage to whatever it is one is trying to water by adding extra energy. So please follow these guidelines. Here is the updated drought monitor.