A couple stormy nights in the city the last couple days will give way to a superb weekend of mostly sunny skies and warm, but comfortable temperatures. High pressure will remain in control over the region’s weather going into next week. The next chance for significant precipitation won’t enter the picture until mid-week next week.
Rest of today – mostly sunny with high temperatures ranging 84-87°F. There is a slight chance for an isolated shower or thunderstorm later this afternoon with a weak disturbance pivoting through at the upper-levels. Forecasters cite the lack of any significant convective inhibition so storms could pretty easily get going, however, moisture content isn’t all that great. Overnight lows should be mild in upper-60s.
HRRR model simulated radar for 4:45PM today
Saturday – with a cold front passing today, we’ll have cooler temperatures tomorrow, high temperatures reaching only into the low-80s under mostly sunny skies. Overnight lows cooling into the mid-60s.
Weather Prediction Center surface forecast for 8PM Saturday
Sunday – just another beautiful day with mostly sunny skies and high temperatures in the low-80s. Overnight lows starting to warm back up into the upper-60s.
Monday – temperatures will warm back up as the high pressure center shifts east, and we get the warmer southerly, and westerly return flow. We should see high temperatures in upper-80s and overnight lows in the low-70s.
During my time taking classes as part of Penn State University’s Undergraduate Certificate in Weather Forecasting, we were taught that understanding the climatology of the location you are interested in is an important prerequisite for making accurate forecasts. This post continues on this theme, adding a climatology for August.
City Name / Station ID: New York, NY (LaGuardia Airport – KLGA)
Local Geography and Topography
Station Elevation: 10 feet above sea level.
Station Location: LaGuardia Airport (KLGA) is situated on the north shore of Queens along the East River, approximately 6 miles east-northeast of Midtown Manhattan.
KLGA’s location within the broader NYC area, as seen in a Google Maps terrain view
Important Topographical Features: New York City is located in the extreme southeastern corner of New York State, bordering suburban New Jersey and Connecticut. These suburban regions combined with those in Long Island comprise the Greater New York City Metropolitan Area, which is the most populous urban agglomeration in the United States and one of the populous urbanized areas in the world with an estimated population of 18 million. New York City itself sprawls across the coastal plain around the Hudson River estuary. The terminal moraine formed by glaciers of the last Ice Age result in a ridge of higher terrain that cuts a swath from southwest to northeast across the boroughs from northern Staten Island, northern Brooklyn, southwestern through central and northeastern Queens. Otherwise, the city itself is low lying. This ridge varies in height between 200-400 feet, rising sharply from south to north, but tapering more gently north. North and west of the city (about 30-50 miles away), lie significant elevations of the Catskills (north), Poconos (west), Taconics that are part of the broader Appalachian Mountain Range. The elevations of the lower foothills can range from 1000-1500 feet. Some of the elevations in the Poconos and Catskills, west and north of KLGA respectively, peak between 2000-3000 feet. The open expanse of the Atlantic Ocean lies south of KLGA and New York City. Long Island Sound also lies east-northeast. The vast urbanized area of the NYC metropolitan region has significant effects on local microclimates via differential heating (urban heat island effect). KLGA is in a low-lying area sensitive to UHI effects and marine influences.
On winter mornings, ocean temperatures which are warm relative to the land reinforce the effect of the city heat island and low temperatures are often 10-20 degrees lower in the inland suburbs than in the central city. The relatively warm water temperatures also delay the advent of winter snows. Conversely, the lag in warming of water temperatures keeps spring temperatures relatively cool. One year-round measure of the ocean influence is the small average daily variation in temperature.
National Weather Service – NYC Office
Wind Patterns
Below is a wind rose – you can read more about how to interpret this chart here.
Frequency (percentage) of the single most common wind direction: Due south (12.25%).
Directions that are most and least common: Most common wind directions include due southwest (10%), due northeast (9.75%), and south-southwest (8.75%). Least common wind directions are east-southeast (1%), due southeast (2.5%), and due east (2%).
Direction(s) most likely to produce the fastest winds: Winds of 16.5-21.4 knots are most frequently found coming from due northeast, and due south. It appears that due northeast also has some probability of exceeding 21.4 knots.
Direction(s) least likely to produce the fastest winds: As is the case with several other months, the least common wind directions of due east, east-southeast, and due southeast also rarely seen winds in excess of 16.4 knots.
Impacts of wind direction on local weather: August winds continue to exhibit a distinctive summer pattern, and share many of the characteristics of the wind profiles for June and July. Southerly and southwesterly winds are a touch less common in August versus July, while northwesterly winds increase in frequency slightly. Like in July, heat waves can accompany the clockwise return flow from the southwest when subtropical Bermuda highs set up southeast of the area. A slight down tick in the frequency of southerly winds may point to a decline in sea breezes, with sea surface temperatures continuing to warm and narrowing the gap with average air temperatures. Increases in northwesterly winds could be an indication of a stronger influence from Canadian high pressure.
Maximum observed two-minute wind speed for the month: 45 (52 mph)
Temperature and Precipitation Averages/Records
Temperature units are in Fahrenheit and precipitation is in inches.
Unsettled weather takes hold during the mid-week period as a couple prefrontal disturbances affect the area. The focus for heavier rain will be later Wednesday as a cold front approaches. Behind this cold front, conditions should improve and result in a pleasant, dry weekend.
Rest of today – mostly cloudy with a chance of isolated showers and thunderstorms later in the day as a shortwave trough lingers around the area. Temperatures in the mid-80s. Overnight lows in the low-70s.
Weather Prediction Center surface forecast for 8PM Wednesday
Wednesday – mostly cloudy with high temperatures in the mid-80s. Heavy rain possible especially later in the day with a cold front approaching. With a moist air mass in place, some thunderstorms that pop up could produce heavy downpours and localized flooding. Rain could continue overnight in more isolated form. Lows in the low-70s.
Thursday – brief subsidence behind the cold front that passes through Thursday should result in calmer weather and warmer temperatures with high temperatures in the upper-80s. Before that happens though, rain and thunderstorms can still pop up. Overnight lows in the low-70s.
Climate Prediction Center 6-10 temperature outlook valid Aug 11 – Aug 15 (this Sunday into next week)
Friday – cooler, sunny, with high temperatures in the low-80s. Overnight lows cooling into the upper-60s as Canadian high pressure begins to build.
After last night’s rains, we’ll see high pressure builds over there weekend. This will lead to mostly sunny and warm weather for the forecast period. A dry cool front passing Sunday won’t do much to cool things off. Instead, temperatures will continue an upwards trend into next week. It remains to be seen what sensible impacts the remnants of Tropical Storm Barry could have for us late next week.
Rest of today – warm, with mostly sunny skies. High temperatures in the upper-80s despite the cold front passing due to warning influence of downsloping westerly winds. Overnight lows in the low-70s.
Weather Prediction Center surface forecast for 8AM Sunday
Saturday – could see some high temperatures and sunny skies in the low-90s in denser urban areas away from the coast. Otherwise most areas in the upper-80s except at the immediate coast where a sea breeze should develop. Overnight lows in the mid-70s.
Sunday – mostly sunny with highs similar to Saturday in the upper-80s. Overnight lows in the mid-70s.
Looking ahead into the medium range, 6-10 day Climate Prediction Center temperature outlook for 7/17-7/27. Much of the country including our area looks set to see above average warmth.
Monday – yet another day of mostly sunny skies and high temperatures in the mid-upoer 80s. Overnight lows in the mid-70s.
This weekend starts off with warm temperatures, and then will get punctuated by the passage of a cold front bringing showers and thunderstorms later tomorrow afternoon into the evening hours. Behind this front, a cooler, drier Canadian air mass moves in with high pressure building to start next week.
Rest of today – warm, with mostly cloudy skies and high temperatures in the upper-80s. Overnight lows in the mid-70s. Slight chance for showers and thunderstorms going into Saturday.
Weather Prediction Center surface forecast for 8PM Saturday
Saturday – mostly cloudy with chances for showers and thunderstorms peaking in the late afternoon and early evening hours. High temperatures in the upper-80s. Shower and thunderstorm chances will peak late with instability and lift maximized from daytime heating and an approaching. Some of these storms could be strong in nature and with plenty of moisture available, these could bring heavy downpours. Overnight lows in the mid-70s.
Sunday – generally improving conditions with decreasing clouds and high temperatures in the mid-80s. Some showers still possible early. Overnight lows into Monday in the low-70s.
GFS Model for 1000-500 mb thickness, surface pressure, and precipitation at 2AM Monday
Monday – a nice day with high temperatures in the low-mid 80s and sunny skies as high pressure takes control. Overnight lows in the upper-60s.
During my time taking classes as part of Penn State University’s Undergraduate Certificate in Weather Forecasting, we were taught that understanding the climatology of the location you are interested in is an important prerequisite for making accurate forecasts. This post continues on this theme, adding a climatology for July.
City Name / Station ID: New York, NY (LaGuardia Airport – KLGA)
Local Geography and Topography
Station Elevation: 10 feet above sea level.
Station Location: LaGuardia Airport (KLGA) is situated on the north shore of Queens along the East River, approximately 6 miles east-northeast of Midtown Manhattan.
KLGA’s location within the broader NYC area, as seen in a Google Maps terrain view
Important Topographical Features: New York City is located in the extreme southeastern corner of New York State, bordering suburban New Jersey and Connecticut. These suburban regions combined with those in Long Island comprise the Greater New York City Metropolitan Area, which is the most populous urban agglomeration in the United States and one of the populous urbanized areas in the world with an estimated population of 18 million. New York City itself sprawls across the coastal plain around the Hudson River estuary. The terminal moraine formed by glaciers of the last Ice Age result in a ridge of higher terrain that cuts a swath from southwest to northeast across the boroughs from northern Staten Island, northern Brooklyn, southwestern through central and northeastern Queens. Otherwise, the city itself is low lying. This ridge varies in height between 200-400 feet, rising sharply from south to north, but tapering more gently north. North and west of the city (about 30-50 miles away), lie significant elevations of the Catskills (north), Poconos (west), Taconics that are part of the broader Appalachian Mountain Range. The elevations of the lower foothills can range from 1000-1500 feet. Some of the elevations in the Poconos and Catskills, west and north of KLGA respectively, peak between 2000-3000 feet. The open expanse of the Atlantic Ocean lies south of KLGA and New York City. Long Island Sound also lies east-northeast. The vast urbanized area of the NYC metropolitan region has significant effects on local microclimates via differential heating (urban heat island effect). KLGA is in a low-lying area sensitive to UHI effects and marine influences.
On winter mornings, ocean temperatures which are warm relative to the land reinforce the effect of the city heat island and low temperatures are often 10-20 degrees lower in the inland suburbs than in the central city. The relatively warm water temperatures also delay the advent of winter snows. Conversely, the lag in warming of water temperatures keeps spring temperatures relatively cool. One year-round measure of the ocean influence is the small average daily variation in temperature.
National Weather Service – NYC Office
Wind Patterns
Below is a wind rose – you can read more about how to interpret this chart here.
Frequency (percentage) of the single most common wind direction: Due south (13.5%).
Directions that are most and least common: Most common wind directions include due southwest (9.5%), due northeast (9.25%), and due northwest (8.5%). Least common wind directions are east-southeast (1%), due east (2%), and due southeast (2.5%).
Direction(s) most likely to produce the fastest winds: Winds of 16.5-21.4 knots are most frequently found coming from due northwest, and due south.
Direction(s) least likely to produce the fastest winds: As is the case with several other months, the least common wind directions of due east, east-southeast, and due southeast also rarely seen winds in excess of 16.4 knots.
Impacts of wind direction on local weather: July winds are remarkably similar to June. Southerly and southwesterly winds are a bit more common in July than in June, and northwesterly winds a little less so. This pattern of winds continues to suggest the influence of mid-latitude lows tracking inland north of the area, bringing more southerly warm sector flow. As with June, persistent, subtropical high pressures continue to be a factor at times in July over the western North Atlantic. The clockwise flow around these high pressure centers would result in more southerly and southwesterly winds, which can lead to the onset and maintenance of heat waves. Southerly winds (along with easterly and some northeasterly winds) would bring cooler, and more stable marine air, sometimes in the form of sea breezes. Sea breezes can become commonplace during this month whenever there’s light synoptic winds. At this point in the year, the average max temperatures well exceed the threshold of 5-7°F warmer than sea surface temperatures (which are slowly climbing through the mid-60s) required for sea breezes.
Maximum observed two-minute wind speed for the month: 46 (53 mph)
Temperature and Precipitation Averages/Records
Temperature units are in Fahrenheit and precipitation is in inches.
Worth Noting
July is the month when average temperatures peak at 86ºF. However, sweltering heat is possible well beyond this point, and record highs in this month are frequently in the upper-90s. Meanwhile, record highest low temperatures can easily be in the upper-70s and low-80s – making for very uncomfortable nights. July is also on average the wettest month of the year, which makes sense given the possibility for thunderstorms and a connection to tropical moisture.
Weather this week will mostly be governed by the presence of high pressure, with the exception of a cold front sweeping through Tuesday night into Wednesday that could bring some showers and thunderstorms. Temperatures will remain warm in the upper-80s and low-90s during this time. July 4th festivities look to be safe from any rain at this time.
Rest of today – sunny skies with high temperatures in the mid-80s. Overnight lows in the low-70s.
Weather Prediction Center surface forecast for 8PM Tuesday
Tuesday – mostly sunny with high temperatures in the upper-80s, close to 90°F. Chance of showers and thunderstorms later in the day as a cold front approaches from the north. Overnight lows in the low-70s.
Wednesday – high pressure starts building again with mostly sunny skies expected. High temperatures in the upper-80s with overnight lows in the low-70s.
Climate Prediction Center forecast for temperature trends between Jul 6-10, showing possibility for above average warmth to continue into the weekend.
Thursday (Independence Day) – another day of slightly above average warmth with high temperatures forecast in the upper-80s. Increasing clouds due to the approach of a weakening warm front from the southwest. Overnight lows in the low-70s, rain should hold off for fireworks viewing.
We start the weekend with hot temperatures but some showers and thunderstorms Saturday and Sunday should cool things off back to near-normal warmth. In general, there’s going to be enough sun this weekend to enjoy some outdoor activities. Just be prepared for a quick moving afternoon thunderstorm. Saturday’s storms could edge into the severe range.
Rest of today – hot, sunny, with high temperatures ranging in the upper-80s to low-90s. Overnight lows in the low-70s.
Storm Prediction Center convective outlook for Saturday, showing slight risk for severe thunderstorms in NYC
Weather Prediction Center surface forecast for 8PM Saturday
Saturday – partly sunny with increasing clouds later in the day. Showers and thunderstorms possible especially in the afternoon and early evening hours when solar heating is maximized and a cold front/shortwave trough moves through the area. There is some potential for the storms to reach severe limits, with the primary threat being damaging winds. High temperatures near 90°F, with overnight lows in the low-70s.
Sunday – cooler, with high temperatures in the mid-80s but mostly sunny skies. There’s also a chance for showers and thunderstorms with a second cold front pushing through during the day, but coverage will be more scattered and storms are expected to be weaker if they form due to lack of upper-air support and less favorable conditions for instability. Overnight lows noticeably cooler, in the mid-60s.
GFS model output for 1000-500 mb thickness, surface pressure, precipitation for 8AM Monday
Monday – a gem of a day with mostly sunny skies and temperatures in the low-80s. Overnight lows back into the upper-60s.
Lingering showers and cloudiness should clear the area later today. Summer officially starts today and a welcome pattern change will coincide with this, giving us excellent weather this weekend. A break from the rain with lots of sunshine is in store. Upper level ridging should block any inclement weather from hitting until a weak storm system passing late Monday into Tuesday.
Rest of today – skies gradually clearing by late afternoon. High temperatures moderated by cloud cover, rising to the upper-70s. Overnight lows in the low-60s. Air mass will be drying out behind a cold front passing today.
Weather Prediction Center surface forecast for 8AM Saturday
Saturday – sunny with highs in the low-80s. High pressure building over Ontario and Canada should keep things nice and calm. Overnight lows in the mid-60s.
Sunday – another sunny day with highs in the low-80s. Overnight lows in the mid-60s.
GFS model output of 500 mb heights and vertical vorticity valid for 8PM Monday
Monday – mostly sunny with increasing clouds late and high temperatures in the low-80s. Overnight lows in the upper-60s with chances for rain.
A cold front that pushed through overnight leaves us with some cool, crisp air to start the weekend. The first half of the weekend will be characterized by plenty of sun before a slow moving frontal system approaches later in the weekend. This will bring back chances for showers and thunderstorms going into next week when it appears an active weather pattern could take root.
Rest of today – mostly sunny with high temperatures in the mid-70s. A post-frontal trough may touch off a few isolated storms later in the afternoon. Overnight lows in the low-60s.
Weather Prediction Center surface forecast for 8AM Saturday, showing high pressure off the coast of NC
Saturday – mostly sunny with highs in the low-80s. High pressure takes hold off the Southeast US coast, with clockwise return flow bringing some warmer air this way. Overnight lows in the low-60s.
Sunday – with a frontal boundary approaching from the northwest, clouds increase and chances for showers and thunderstorms do also. High temperatures should still be mild in the low-80s. As the Overnight lows in the mid-60s with rain chances continuing.
NAM output of 1000-500 mb thickness, surface pressure and precipitation for 8PM Sunday.
Monday – the frontal boundary that approaches from the northwest weakens and stalls out. This is partly due to flow at the upper levels flattening out/becoming somewhat parallel to the front’s orientation, and partly due to the high pressure that by this time will become anchored over Bermuda. Multiple waves of low pressure are forecast to move along this stalled front bringing another day that holds chances for showers and thunderstorms. Prolonged southwest/westerly flow ahead of the cold front which really slows down should allow temperatures to reach the mid-80s despite more cloud cover and precipitation. Overnight lows in the upper-60s with yet more rain possible.
