Quarterly climate impacts and outlook for the Gulf of Maine Region: September 2019

Gulf of Maine region significant events – June to August 2019

Long description

The image shows the map of the Gulf of Maine region. It highlights significant weather and climate events that occurred in the summer months of June to August 2019.

There were a few heat waves and frequent thunderstorms in July.

In August, heavy rain from Post-Tropical Cyclone Erin helped ease dry conditions in the Maritimes.


From June 20 to 22, a slow-moving storm brought up to 125 mm (4.90 in.) of rain to the region, with the greatest totals in Nova Scotia. Two homes in Annapolis County, N.S, were evacuated due to land shifting as a result of the heavy rain. Minor flooding occurred in P.E.I. Strong winds behind the system caused two ferry crossings to be cancelled.


July 2019 was the all-time hottest month on record for Boston, MA, and Portland, ME. This July was among the 10 hottest Julys on record for several other sites across the region. Boston had 17 days in July with a minimum (min) temperature of 21°C (70°F) or higher, 10 more than average and its greatest number for any month on record (since 1872). Boston also had its highest average min temperature for any month. The number of days in July with a high of at least 32°C (90°F) ranked among the 10 all-time greatest for any month on record at a couple of sites.

The region experienced a few heat waves during July, with high temperatures reaching 37°C (99°F). During one heat wave, Boston tied its all-time highest min temperature on record, while Portland had its second warmest. Severe thunderstorms often accompanied the heat. See Impacts section for details.

There were also a few instances of flash flooding during the month. For example, up to 178 mm (7 in.) of rain fell in parts of New England from July 11 to 12, flooding streets and basements in southeastern Massachusetts and destroying roads and bridges in central New Hampshire. Cockermouth River in Groton, NH, rose almost 2.4 m (8 ft.) in just over an hour.

On July 23, three EF-1 tornadoes touched down on Cape Cod, MA, uprooting and snapping over 150 trees, damaging buildings, and leaving more than 30,000 customers without power. There have only been three other tornadoes on Cape Cod since 1950.


There were many days in August with thunderstorms and heavy rain. Thunderstorms downed trees and produced ping pong ball-sized hail on August 3 and 4. Flash flooding from up to 102 mm (4 in.) of rain left some roads impassable in parts of New England on August 7 and 8. On August 10, ping pong ball-sized hail pelted Maine and New Brunswick. In that province, up to 90 mm (3.50 in.) of rain fell in under 3 hours in Shediac and more than 27,000 customers lost power. On August 12, an EF-1 tornado damaged over 100 trees in Washington County, ME. Severe storms on August 21 produced funnel clouds in New England.

From August 29 to 30, a cold front and moisture from post-tropical cyclone Erin brought up to 160 mm (6 in.) of rain to the region, with the greatest totals in Nova Scotia. Rainfall rates exceeded 30 mm/h (1 in./hr) in a few locations. Several sites set single-day rainfall records. Flash flooding washed out roads and impacted buildings, including 60 single-family dwellings, in Nova Scotia. Around 15,000 customers lost power in that province. Some shellfish harvesting areas were shut down in parts of the Maritimes.

Regional climate overview- June to August 2019

Precipitation: summer percent of normal

Long description

The map of total precipitation as a percentage of normal precipitation shows that northwestern sections of New Brunswick, Maine, and parts of New Hampshire was drier than normal.

It shows that sections of New Brunswick and Nova Scotia bordering on the Bay of Fundy were wetter than normal, as were coastal sections of the New England states. Parts of coastal Maine received 150 to 175% above the normal amount of precipitation.

Summer precipitation (accumulated from June to August) ranged from 25% of normal to 175% of normal. It was the fifth driest summer on record for Caribou, ME.

June precipitation ranged from 50% of normal in parts of New Brunswick to more than 200% of normal in parts of Nova Scotia. This June ranked among the five wettest on record for several Maritimes sites.

July precipitation ranged from 25% of normal to near normal for most areas. July 2019 was among the 10 driest on record for a few Maritimes locations. However, eastern Massachusetts, Downeast Maine, and parts of Nova Scotia saw up to 200% of normal.

August precipitation ranged from 50% of normal in northern New Brunswick and southeastern Massachusetts to more than 200% of normal in Downeast Maine.

U.S. precipitation normals based on 1981–2010 data; Canadian precipitation normals based on 2002–2018 data.

Accumulated precipitation compared to normal during summer. Green areas indicate a surplus, while brown areas denote a deficit. Credit: U.S. National Oceanic and Atmospheric Administration (NOAA)’s Climate Prediction Center (CPC).
Long description

The time series graph of the accumulated precipitation over the months of June to August 2019 compared to normal for Fredericton, N.B., shows that the accumulated precipitation was above normal from mid-June to the end of July. The accumulated precipitation was below normal through August.

Accumulated observed: thick line. Accumulated normal: thin line. Green-shaded areas show where the observed accumulated amount was above normal. Brown-shaded areas show where the observed amount was below normal.

The scale on the left is in inches, from 0 to 10 in. The scale on the right is in mm, from 0 to 250 mm.

Temperature: summer departure from normal

Long description

The map of summer temperature departure from normal, averaged over June to August 2019, shows that Nova Scotia and much of Maine had near-normal temperatures.  Warm anomalies were most evident over New Brunswick (up to 1° C above normal) and eastern Massachusetts (up to 2° C above normal).

The scale to the right defines the map colours. Shades of red represent positive anomalies (above normal), to +5 degrees Celsius and above. Shades of blue represent negative anomalies (below normal), to negative 5 degrees Celsius and below (shades of blue). White indicates near-normal conditions (+0.5 Celsius to -0.5 Celsius).

Summer temperatures (averaged over June, July, and August) were up to 2°C (4°F) above normal for most of the region. It was the fourth warmest summer on record for Boston, MA.

June was a cool month, with temperatures as much as 2°C (4°F) below normal for most areas.

July was a hot month for most areas. Temperatures were up to 3°C (5°F) above normal, with the warmest areas in New England.

August temperatures were up to 2°C (4°F) warmer than normal.

Temperature normals are based on 1981 to 2010 data.

Sea surface temperatures: summer departure from normal

Long description

The map of sea surface temperature departure from normal, averaged over June to August 2019 shows colder-than-normal conditions in shades of blue, warmer-than-normal conditions in shades of pink, and near-normal as white. The main text describes details.

The scale to the right defines the map colours. Shades of red represent positive anomalies (above normal), to +3 degrees Celsius. Shades of blue represent negative anomalies (below normal), to -3 degrees Celsius. White indicates near-normal conditions (departures near 0 degrees Celsius).

Cold sea surface temperature anomalies from spring continued only in specific regions associated with the outer edges of the Maine Coastal Currents, the coastal area southwest of Nova Scotia and along the New Brunswick shore of the Bay of Fundy. Elsewhere, warm temperature anomalies dominated, weak [less than 0.5°C (1°F)] along the New England coast but reaching 1°C (2°F) over the central Gulf of Maine and 1.5°C (3°F) along the Atlantic coast of Nova Scotia. Sea surface temperature normals are based on 1985 to 2014 data.

Regional impacts - June to August 2019

July heat and severe weather

The region experienced a few heat waves and several days with severe thunderstorms during July. From July 4 to 6, maximum (max) temperatures were as high as 35°C (95°F), with the humidity making it feel as hot as 41°C (106°F). Severe thunderstorms occurred with the passage of a cold front on July 6. Trees and wires were downed in Maine and New Hampshire. Torrential rain also occurred, with a report of 25 mm (1 in.) of rain in 15 minutes in western Maine.

Another heat wave from July 19 to 22 had max temperatures of up to 37°C (99°F), but it felt as hot as 44°C (111°F). Humidity levels were unusually high. For instance, at 11 PM on July 20, Boston, MA, had a dew point of 25°C (77°F), which ranks among some of the highest dew points on record for the site. Low temperatures were record setting in some locations. On July 21, Boston tied its all-time highest minimum temperature on record (since 1872) with a low of 28°C (83°F), while the low of 24°C (76°F) in Portland, ME, ranked as its second all-time hottest on record (since 1874). A cold front brought relief from the heat but also helped spark severe storms in Maine, southern New Brunswick, and Nova Scotia on July 21. Strong wind gusts knocked down trees, branches, and wires. NS Power reported more than 44,000 customers lost power, with most outages in the Halifax area. Downpours led to localized flooding in southern New Brunswick and northern Nova Scotia, while ping pong ball-sized hail damaged vehicles in central Maine.

Uprooted tree in Halifax, N.S., caused by a severe thunderstorm on July 21, 2019. Image courtesy of Canadian Broadcasting Corporation (CBC)/Craig Paisley.
Long description

The photo shows an uprooted deciduous tree lying across a sidewalk. The concrete road edge is broken and raised. Branches of the fallen tree partially obscure the houses behind.

From July 28 to 31, max temperatures reached 36°C (96°F), setting several high temperature records. With the humidity, it felt as hot as 41°C (106°F). Salmon pools on sections of the Nepisiguit and Miramichi rivers in New Brunswick were closed for fishing due to higher-than-normal water temperatures, which are stressful to fish. Severe thunderstorms in Nova Scotia on July 29 produced very heavy rainfall for localized areas. A private road near Antigonish, N.S., washed out in the downpours, with a nearby weather station reporting 66.3 mm (2.60 in.) of rain in three hours. On July 31, severe storms knocked down trees and wires and caused power outages in New England. A microburst with winds of up to 129 km/h (80 mph) caused a ground stop at Boston's Logan Airport, delaying hundreds of flights, and capsized several sailboats in nearby Winthrop. Golf ball-sized hail was reported in New Hampshire.

Daily temperature range (blue bars) during July 2019 in Boston, MA, compared to normal temperature range (tan area), record max temperature (red line), and record min temperature (blue line). Credit: U.S. Northeast Regional Climate Center.
Long description

The time series graph of temperatures is for the Boston Area of Massachusetts, for July 2019. It shows how daily temperatures compared to the normal (long-term average) and to the historical extreme values. Temperatures were generally warmer than normal this month. The daily maximum temperatures approached record values on several days. The minimum temperatures even reached or exceeded the normal maximum temperatures on July 20 and 21.

The blue bars represent the daily temperature range (between the daily maximum and minimum temperatures). The tan-shaded area represents the normal temperature range. The red and blue lines represent the record daily maximum and minimum temperatures. The pink-shaded area shows the top of the normal range (i.e. the average maximum temperature) and the record maximum temperatures. The blue-shaded area shows the bottom of the normal range (i.e. the average minimum temperature) and the record minimum temperature.

The scale on the left ranges from 40 to 110 degrees Fahrenheit. The scale on the right ranges from 4.4 to 43.3 degrees Celsius.

Summer conditions

The cool, wet June delayed the planting of crops and hampered farming activities in the region. However, the conditions helped apple orchards in P.E.I. and kept cranberry growers in Massachusetts from having to irrigate. Bursts of heavy rain in early summer and warm temperatures in July contributed to harmful algal blooms. Several bodies of water in New England were closed, as were some shellfish farms along the coastline. An algae advisory was issued for a portion of the St. John River in New Brunswick, and officials in Nova Scotia advised the public to avoid the water in Lake Ainslie, parts of the Margaree River, Sandy Lake, and Lake Micmac due to harmful algae blooms. The wet conditions also contributed to an abundant mosquito population, increasing the risk of contracting mosquito-borne viruses.

Warmer, drier weather in July and August stressed crops and delayed harvest in the Maritimes and caused some New England farmers to irrigate. In Nova Scotia, Halifax Water asked residents in Dartmouth and nearby areas to conserve water and some wells ran dry along the Eastern Shore. Hot weather led to increased water use, which caused discolored water in Moncton, N.B. During July and August, abnormal dryness was introduced in northern New Brunswick, parts of mainland Nova Scotia, southern Maine, and New Hampshire. Rain at the end of August from post-tropical cyclone Erin improved dry conditions in Nova Scotia and parts of New England.

Very dry conditions caused reduced potato crop yields in P.E.I. Image courtesy of Laura Meader/Canadian Broadcasting Corporation (CBC).
Long description

The photo shows harvesting operations in a dry potato field in Bellevue, P.E.I., with a truck raising dust as it drives, while a harvester vehicle in the background is almost completely obscured by dust.

Right Whales

From June through July, eight North Atlantic Right Whales were found dead, mainly in the Gulf of St. Lawrence. Increased numbers of the whales in the Gulf are thought to be linked to warming ocean temperatures and shifting of the location of the whales’ food sources.

Regional outlook - autumn 2019

Temperature and precipitation

U.S. National Oceanic and Atmospheric Administration (NOAA)’s Climate Prediction Center (CPC) temperature outlook produced August 15 (left); Environment and Climate Change Canada (ECCC) temperature outlook produced August 31 (right).
Long description

The map of the temperature outlook for September to November for New England issued in mid-August (left) shows much of the area with a 60 to 70% probability of above-normal temperatures.

The map of the temperature outlook for September to November for the Maritimes issued at the end of August (right) shows that Nova Scotia has the highest chance of above-normal conditions, with probabilities of 50 to 60%. Southern New Brunswick and Prince Edward Island also have an increased chance of above-normal conditions. There is no signal for either above or below normal conditions over the rest of New Brunswick.

For September to November, NOAA's Climate Prediction Center (CPC) and Environment and Climate Change Canada (ECCC) favor an increased chance of above-normal temperatures for New England, Nova Scotia, southern New Brunswick, and central and eastern P.E.I. Equal chances of below-, near-, or above-normal temperatures were forecast for western P.E.I. and central and northern New Brunswick.

For precipitation, both groups call for equal chances in the region for September to November.

Atlantic hurricane season

NOAA's updated 2019 Atlantic hurricane season outlook indicates an above-normal season is most likely, with 10 to 17 named storms (winds of 63+ km/h), of which 5 to 9 will become hurricanes (winds of 119+ km/h), including 2 to 4 major hurricanes (Category 3, 4, or 5; winds of 178+ km/h). The increase is due to ENSO-neutral and other favorable conditions. The season runs from June 1 to November 30, peaking from mid-August to late October.

Quantity 2019 season outlook Average Season
Number of named storms 10 to 17 12
Number of hurricanes 5 to 9 6
Number of major hurricanes 2 to 4 3

El Niño/Southern Oscillation (ENSO)

Long description

Early-September 2019 official probabilistic El Niño Southern Oscillation (EÑSO) forecast, issued by the U.S. Climate Prediction Center (CPC) and the International Research Institute (IRI) for Climate and Society.  

The forecast period in the graph covers about a year. Each interval represents probabilities over 3 months. Each interval overlaps by 2 months. The first 3-month interval is August-September-October (2019). The months of December-January-February are in the middle of the graph. The last 3-month interval is April-May-June (2020).

The graph of forecast probabilities (plotted as vertical bars) shows that the neutral condition is the most probable condition for the entire period. Forecast probabilities of the neutral condition start high at 80% and then decrease slowly but they remain between 50% and 60% for the latter half of the period.

The forecast probability of an El Niño starts low and increases gradually to just under 30% by winter and remains at that level into spring.

The forecast probability of La Niña remains low throughout.

The climatological probabilities (plotted as lines) indicate that the neutral EÑSO condition (grey line) is climatologically more probable for the fall and spring periods. The climatological probability starts at about 50% in the late summer/fall then slowly drops in the winter to about 30% then increases in the spring to about 60%. The climatological probabilities of the El Niño (red line) and La Niño (blue line) conditions are similar to each other, starting at around 30%, increasing to about 35% over the winter, then gradually decreasing to about 20% by spring.

The EÑSO state is based on NINO3.4 Sea surface temperature (SST) Anomaly. The neutral EÑSO is defined as -0.5 °C to 0.5 °C.

During August, ENSO-neutral conditions were observed in the equatorial Pacific Ocean. NOAA's Climate Prediction Center indicates there is around a 75% chance that ENSO-neutral conditions will continue through winter 2019–2020 and a 55%–60% chance that these conditions will continue through spring 2020.


Environment and Climate Change Canada
Email: ec.enviroinfo.ec@canada.ca

National Oceanic and Atmospheric Administration (NOAA)

Northeast Regional Climate Center
Name: Ellen Mecray
Email: Ellen.L.Mecray@noaa.gov

Name: Samantha Borisoff
Email: sgh58@cornell.edu

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