The Northeast of the US has seen above normal precipitation over the last couple of weeks and it is expected to continue to see rain for the 4th of July holiday weekend and into next week. This rain will affect your outdoor plans over the coming days but it is alleviating drought conditions for several areas. Let’s take a look at why so much rain has fallen and what the forecast looks like this weekend.

This graphic was created using the High Plains Regional Climate Center Climate Maps. 

Several areas are above 1 inch over the average (green to blue) over the past 14 days. Some areas are still below the average (yellow) because several of the storm systems have brought thunderstorms, which can create heavy rain in some areas but little in others.

Why has there been above normal rain?

There has been above normal rain over the past 2 weeks because of a dip in the jet stream, that has tracked storm systems over the Northeast. Storm systems often follow the jet stream, therefore have brought what feels like continuous rain to the Northeast. 

The map below indicates departure from normal "heights" in the upper atmosphere at approximately 18,000 feet above sea level. Positive (+) anomalies indicate higher heights and stronger "ridging" than normal, and negative (-) anomalies indicate lower heights and more "troughing" than normal.

This troughing in the upper levels of the atmosphere is associated with the jet stream and is bringing the above average rainfall to many areas in the Northeast. While the rain might be dampening some of your early Summer outdoor adventures, it is providing beneficial rain to areas in a drought. 

The beneficial rain is a tale of two stories because it has caused some flooding over the past week due to strong thunderstorms bringing heavy rain. The National Weather Service issued several Flood Watches throughout New England earlier this week.  

New England's tallest point Mount Washington has even broken the record amount of precipitation in June with a total so far as of June 28th of 17.28 inches. The previous record is from 1973 of 16.00 inches with records dating back to 1933. More rain is expected over the coming days that will continue to break this record on Mount Washington. 

It has been a month of extremes for the tallest point in the Northeast as they broke the June record snow earlier this month of 8.4 inches, beating the record of 8.1 inches from 1959. 

More Rain for the Holiday Weekend

More rain is in the forecast throughout the Northeast this upcoming weekend and early next week. The jet stream and upper level trough will remain over the region and cause the storm track to continue through the start of July. Here is a quick highlight of each day moving forward for the Northeast altogether:

Thursday, June 29th 

• Scattered light showers and a possible thunderstorm in New England
• Clear with wildfire smoke and haze to the south and west

Friday, June 30th

• A few afternoon showers and thunderstorms will develop in the western half of the Northeast and the mountains in New England
• Lingering wildfire smoke and haze throughout the region
• Best day to get outside in this forecast

Saturday - Sunday, July 1st & 2nd

• Scattered rain showers throughout the region with thunderstorms possible
• Wildfire smoke and haze clear

Monday - Tuesday, July 3rd & 4th 

• Scattered rain showers throughout the region with thunderstorms possible
• Wildfire smoke and haze could return

Here is a look at the ECMWF (Euro) model’s depiction of precipitation type and intensity from 11 am Friday, June 30th to 2 pm Tuesday, July 4th. 

The theme of this forecast is the word ‘scattered’. The coming days will not be a washout but rather have consistent scattered showers and thunderstorms throughout the region. There will be pockets of sunshine over the coming days in between the rounds of showers and storms. 

Both the ECMWF (Euro - left) and GFS (right) give most of the Northeast at least an inch of rain with several areas approaching 3 inches. The models show the locations of thunderstorms differently, which will have a big impact on who sees the most rain this weekend and early next week. 

Temperatures look fairly average over the coming days with 60s/70s in the north, 70s/80s through the central Northeast, and 80s/90s further south. Humidity will be a factor with dewpoints in the 60s and 70s. 

An additional factor this weekend will be wildfire smoke transport from Canada which we highlighted in an article from Tuesday here. The track of the storm systems bringing the rain will also bring smoke transport into the US. If rain is continuous enough, it should help alleviate the haze and poor air quality by diluting the atmosphere. 

OpenSnow surface smoke map forecast on Saturday morning, July 1st.

The OpenSnow maps will be your best friend this holiday weekend to keep a current eye on the sky. I would recommend booking the Radar, Forecast Radar, and Smoke map. Have a great weekend!

Zach Butler