Heavy Rain through Tonight, Dry and Breezy Tomorrow

Casey's Saturday Evening Forecast
Published: May. 20, 2023 at 7:20 PM EDT
Email This Link
Share on Pinterest
Share on LinkedIn

SPRINGFIELD, Mass. (WGGB/WSHM) - Well, friends…are you ready for it!? …The Midnight Rain, that is. We needed a good soaking, and now we’re getting one! The only negative—the timing! If you’re heading east tonight to Gillette Stadium, you will NEED that umbrella, and the poncho! With those two handy tools in mind, you should be able to just shake it off! You should also plan on taking extra time getting to and from the stadium. No “look what (the rain) made me do” moments for us tonight, right?

Here’s the story: we’re tracking a complicated setup with an area of Gulf-low pressure moving northeastwards up the coast, while a cold front associated with another low moves in from the northwest. The result: heavy, significant rain with a chance for some street and low-lying area flooding and ponding.

As these two systems move towards our area, they’re going to try to do something we meteorologists call “phasing”. This is a fancy term for merging—but, the key is, when two storm systems phase, the combined system gains energy in the process. Think of it like a violin player who is joined by a bassist and a drummer. The result of them playing together is more than the sum of their individual contributions, right?

So—the takeaway is, these storm systems merge over us, and we end up with a much-needed rainy evening. The exact timing of the phase will be the determining factor in how much rain we get. Right now, it looks like the phase starts to occur just as the storms cross through our region. As a result, most of our rain comes from our coastal low—which gets enhanced by its interaction with the cold front. The rain has already arrived, and it will continue tonight through the overnight hours, heavy at times—particularly between 8PM & 1AM, when downpours and a rumble of thunder are possible. For our enchanted Taylor Swift fans, you might need to bring the cardigan with that chilly rain lasting longer for you. Your heaviest rain will occur between 4-6PM, and again from 9PM-3AM. Bring the rain gear, and you’ll be gorgeous, but don’t blame ME! If you forget. At that point, you’ll be on your own, kid. I’m not the anti-hero in this story. Winds will also be breezy, particularly in the east at Gillette Stadium with gusts up to 25 MPH. The stadium should help block some of that wind, though.

Our cold front moves through overnight, but its moisture will pull further north—the southern moist sector falls apart, so the front will instead put an end to our rain, from northwest to southeast, as it crosses through between 12AM and 4AM through our state.

We’ve been well below average so far this month in terms of rainfall, and all our plants really need the moisture. Models suggest the system should give many of us around 1-2″ of rain, the higher totals being wherever the heavier shower and storm bands try to set up. Further east, our Rhode Island friends might see a few pockets of 3-4″ of rain—wow! I believe we’ll end up being on the higher side of these numbers ourselves. Phasing storm systems tend to be tricky to get right for weather models. A few models try to keep the heaviest rain just to the Southeast of our area, others suggest a second “axis” right over us. I’m leaning towards the latter idea and think some of us are actually going to be seeing totals closer to 2.5″+ this evening. With rainfall amounts that significant, street and pond flooding does become a concern. So, whether heading back from the concert late tonight, coming back home from the city or just a friends’ house, take extra time on the roadways! Slow down. Pay extra attention to low lying areas—the bottoms of hills, and on sharp turns. Keep your reputation intact and avoid needing a getaway car after you do something bad.

We’ll drop down into the mid-50s this evening behind the front, which crosses us between 2AM and 3AM, and winds will turn out of the northwest (remember: northwest wind, in general = chilly!). That flow will dry us out and our dewpoints take a dive. We’ll warm back into the mid-70s Sunday with plenty of sunshine. Winds will start off light, but pick up during the afternoon and we’ll end up on the breezy side, with some gusts up to 25mph. There’s an interesting reason for that too: winds above us…say around 3,000 to 4,000 feet up, will still be breezy after that cold front departs. Overnight, we won’t have any way to get those winds down to the surface, but with the sunshine on Sunday, we’ll get a cool phenomenon called “mixing”—the air at the ground will heat up, rise, and cool. When it does so, it will “grab” that wind, and then that cool air sinks back down to the surface, bringing the wind with it! Isn’t that cool?!

Looking ahead, we return to a dry and pleasant pattern with plenty of sunshine, highs in the mid to upper 70s—just slightly above average for us for this time of the year. Thursday looks a touch unsettled, with some models hinting at a sprinkle as a cold front tries to approach, but most models keep us dry. We’ll keep an eye on it, either way, not a big deal for us. By Memorial Day weekend, temperatures climb the stairs into the middle 80s!

Looking well ahead… into June, large scale patterns are suggesting a return to more “average” weather—we’ll be wetter, and temperatures for the month look to trend closer to climatological averages. The Climate Prediction Center’s latest summer forecast places us squarely in a “warmer than average” and slightly in the “wetter than average” camp. This is being shown on our long-range climate models rather well, and is associated with an expected development of an El Niño later this summer. All of that is to say: enjoy all of this nice spring-like dry weather, because we’ll be seeing more (average) rain on the distant horizon as the pattern changes. That’s a good thing though, because we’ve been rather dry.

Have a great Saturday evening!