Tag Archives: thunderstorms

NYC Weekend Weather – Aug 21, 2020

A week of refreshing, mostly dry, and seasonable weather gives way to a warming trend this weekend. There will be chances of isolated, diurnally driven thunderstorms both weekend days. By the end of the period, temperatures will be climbing into the upper-80s and low-90s across the region, and the warmer temps look set to carry over into the first half of next week.

Rest of today – mostly sunny with high temperatures in the mid-80s. Overnight lows in the low-70s.

Weather Prediction Center surface forecast for 8AM Saturday. The warm front and weak surface low pictured over the Delmarva is forecast to move north during the day.

Saturday – a weak warm front pushes north during the day. As a result, low clouds should be on the increase. Slight chance of showers and thunderstorms in the afternoon, coverage is likely to not be widespread. Overnight lows in the mid-70s with rain chances continuing.

Sunday – warm and more humid with high temperatures in the upper-80s. Another day where there will be chances for scattered showers and thunderstorms in the afternoon. Overnight lows in the low-70s.

Monday the warm temperatures continue with high temperatures again in the upper-80s, approaching 90ºF under mostly sunny skies. Overnight lows in the low-70s.

GFS 850 mb temperature anomalies valid at 2PM Monday. The deeper the red hues, the more warmer the anomaly. This shows us on the northern side of an 850 mb high, with slightly above normal temperatures at this level as a result. 850 mb temperatures are often a good proxy for surface temperatures.

NYC Weather Update – Aug 17, 2020

After a rainy, cool weekend, temperatures will rebound into the low-80s as high pressure takes over. This will bring about a week of pleasant, mostly dry weather, with plenty of sun all the way through end of the week. Further afield, we’re watching the tropics for 2 possible tropical storms brewing.

Rest of today – sunny with high temperatures in the low-80s. Overnight lows in the upper-60s with some potential for a scattered showers and thunderstorms as a cold front pushes through the region later this evening. Timing of these storms hitting the area appears to be around 8-10PM.

Tuesday – behind this cold front, westerly downsloping winds will actually help temperatures rebound into the mid-80s under mostly sunny skies. Overnight lows in the mid-60s.

Wednesday – mostly sunny with highs in the low-80s. Overnight lows continue in the upper-60s.

Thursday another great day with lots of sun and highs in the low-80s. Overnight lows in the upper-60s.

Watching the tropics

Way out in the tropical Atlantic, we have two tropical waves that the National Hurricane Center is keeping tabs on. These two waves could develop into the 12th and 13th named storms of the 2020 Atlantic Hurricane season, which thus far has been breaking records for the fastest forming named storms, beating out the horrific 2005 season that produced Katrina, Wilma, and some storms that had Greek alphabet names.

National Hurricane Center 5 day graphical tropical weather outlook.

NYC Weather Update – Jul 27, 2020

Possibly record-breaking heat to start off the week with highs in the upper-90s Monday. Tuesday will have slightly cooler temps but similar heat index due to high humidity. This could allow for some strong thunderstorms with the weak cold front passage. This frontal boundary stalls out and becomes stationary. Cooler, drier air finally arrives later this week past.

Rest of today – sunny and hot with high temperatures in the upper-90s. Record breaking highs are possible across the region with strong 850 mb temperature anomalies above the surface. Overnight lows in the upper-70s could break some records for highest minimum temperatures.

Tuesday – although temperatures are overall expected to be cooler in the low-90s with more clouds, an increase in humidity will result in a heat index similar to Monday at or above 100ºF. A weak cold front moves through the region Tuesday evening and this could bring about a few strong to severe thunderstorms. Widespread severe weather is not expected at this time. Overnight lows in the mid-70s.

Wednesday – a bit cooler with high temperatures around 90ºF. Overnight lows continue to be uncomfortable in the mid-70s.

Thursday high temperatures remain warm in the low-90s and mostly sunny skies. Overnight lows in the mid-70s. Looking ahead, above average warmth is still possible next week, even though we are expecting a break from the heat during the weekend.

National Hurricane Center 5 day graphical tropical weather outlook.

NYC Weekend, Tropical Storm Fay Weather – Jul 10, 2020

Tropical Storm Fay will bring heavy rain, strong winds, flash flooding to start the weekend. A Tropical Storm Warning is in effect for all of NYC as well as coastal New Jersey and Connecticut, including all of Long Island. Conditions should start to improve Saturday as Fay continues tracking north and inland. We may even see some sun by Sunday. Temperatures start in the low-80s with the rain and clouds from Fay, but should be warming up upper-80s later on this weekend.

Rest of today – cooler with high temperatures in the low-80s. Windy and rain, with bouts of heavy, tropical downpours. 2-4″ of rain are possible with this storm. Sustained winds could approach tropical storm force (30-40 mph) near Fay’s core if it tracks over us. Otherwise, gusts up to 50 mph are possible. The main threat from Fay is from the heavy rains that could produce flash flooding. Overnight lows in the low-70s with tropical storm conditions still possible as Fay lifts north.

Saturday – as Fay lifts north and inland, it will weaken rapidly. Conditions should improve with a spell of dry weather possible before another non-tropical frontal system impacts the area with thunderstorms possible. Temperatures should be warm, in the upper-80s. Overnight lows in the mid-70s with rain chances diminishing behind the passage of this cold front.

Sunday – we may start off dry with some sun, which could allow temperatures to climb to the low-90s. However, scattered thunderstorms are possible later in the day. Overnight lows in the mid-70s.

Monday similar day to Sunday, with high temperatures in the upper-80s. Partly sunny skies to start and isolated thunderstorms possible later in the day. Overnight lows in the mid-70s.

Weather Prediction Center surface forecast for 8AM Sunday

NYC Weather Update – Jul 5, 2020

A hot, humid, and stormy start to the week with highs in the low-90s. A backdoor cold front moves through, granting a reprieve from heat mid-week with highs cooling off to the mid-80s Tuesday. The heat comes back after this. Later this week, and into the weekend, a storm with possible tropical characteristics could bring heavy rain to the region.

Rest of today – sunny to start with highs quickly climbing into the low-90s. Clouds increase later this afternoon. A shortwave trough will spark the potential for some showers and thunderstorms later this afternoon, around 4PM. These storms could bring heavy rain and gusty winds. Overnight lows in the low-70s with rain chances quickly dying off.

Weather Prediction Center surface forecast for 8PM Monday.

Tuesday – a backdoor cold front will push through overnight. The onshore flow from the northeast behind this front should result in mostly cloudy skies and cooler temperatures in the mid-80s. Showers and thunderstorms could still impact the area in the afternoon. Overnight lows in the low-70s.

Wednesday – the backdoor cold front will return north as a warm front Wednesday. Temperatures will remain stable with high temperatures in the mid-80s with mostly cloudy skies. Isolated showers and thunderstorms will again be possible in the afternoon hours. Overnight lows in the mid-70s.

Thursday high temperatures rebound into the upper-80s and low-90s possibly with fewer clouds as high pressure briefly builds in. Overnight lows in the mid-70s. Looking towards the end of the week, we’ll be monitoring the progress of a low pressure center that the National Hurricane Center has identified as having the potential to develop tropical characteristics. This storm could bring some heavy rain this weekend.

National Hurricane Center 5 day graphical tropical weather outlook.

NYC Weather Update – Jun 29, 2020

An upper low lingering over the Northeast results in unsettled weather to start this week. With the dynamics brought on by this upper low, there will be chances for isolated showers and thunderstorms each day esp. in the afternoon. High temperatures during this period should be generally in the low-80s. Luckily, this pattern should break in time for the Independence Day holiday weekend.

Rest of today – sunny with highs in the upper-80s to start. Chance for isolated showers and thunderstorms in the afternoon. Some of these thunderstorms could approach severe limits though we aren’t anticipating widespread severe weather today. Overnight lows around 70ºF.

Weather Prediction Center surface forecast for 8PM Monday.

Tuesday – more clouds resulting in cooler highs in the low-80s. Closed upper and surface lows over the northeast will provide for ongoing chances of showers and thunderstorms through the day. Coverage should again be scattered in nature. Overnight lows in the upper-60s.

Wednesday – similar day to Tuesday with highs in the low-80s, mostly cloudy with chances for showers and thunderstorms yet again. The closed upper low referenced above and visible in the graphic below will provide for a cold pool that should enhance lapse rates and increase chances for isolated severe thunderstorms. Overnight lows around 70ºF.

GFS model 500 mb temperature, height, and winds, valid for 2PM Wednesday.

Thursday the nagging upper and surface lows will finally move off to the east. This should result in better conditions with sunny skies and no tangible risk for rain and thunderstorms. High temperatures should rebound into the upper-80s. Overnight lows in the low-70s.

NYC Weekend Weather – Jun 26, 2020

A warm and potentially stormy start to the weekend on tap with Storm Prediction Center placing the area under slight risk for severe weather Saturday. Temperatures during this period in the upper-80s. Weather improves on Sunday behind a cold front. Next week, a lingering upper low may bring daily chances for rain in the afternoons.

This afternoon – mostly sunny with a high in the mid-80s. Overnight lows in the low-70s with increasing clouds towards daybreak.

Saturday – a warm front pushes through early in the morning and some showers could accompany this. Mostly cloudy with high temperatures in the upper-80s. A cold front is forecast to push through later, with a prefrontal trough ahead of it. These will serve as the loci for more organized convective activity. Thunderstorms forming in the warm sector behind the early warm front passage may be able to attain severe limits. The main threat is from damaging winds. Overnight lows in the mid-70s with rain chances diminishing early.

Sunday – despite the cold front passage, temperatures stay largely similar to Saturday in the upper-80s due to downsloping winds from the west. With an upper low lingering, isolated, diurnally driven thunderstorms may pop up in the late afternoon, mostly sunny otherwise. Overnight lows in the low-70s.

Monday mostly sunny though a chance for afternoon pop up showers or thunderstorms persists. High temperatures remain warm in the upper-80s. Overnight lows in the low-70s. Below, you’ll see GFS forecasts for this upper low continuing to influence our weather going into next week. The tangible impacts for this will be continued chances of scattered showers and thunderstorms for much of the week until this upper low finally gets picked back up by primary westerly steering currents and moves offshore.

GFS model 500 mb height and wind. You can see evidence of a persistent upper low that drifts south, then gets cutoff from main steering currents, and remains largely stationary, even retrograding west during next week over the Northeast.

NYC Weather Update – Jun 22, 2020

The first official week of summer brings us warm temperatures in the upper-80s (low-90s interior). Early in the week, there will be chances each day for scattered showers and thunderstorms, particularly over inland areas. South facing shorelines should enjoy cooler temperatures with the possibility of sea breezes developign. A cold front passes Wednesday, bringing chances for more organized precipitation. Behind this, skies should clear up but temps remain warm.

Rest of today – mostly sunny with high temperatures around 90ºF. Chance for scattered showers and thunderstorms in the afternoon. Coverage would be spotty at best but with plenty of moisture available, any storms could produce heavy rain. Overnight lows around 70ºF.

Weather Prediction Center surface forecast for 8PM Tuesday.

Tuesday – similar to today, with high temperatures peaking near 90ºF and mostly sunny skies to start, then more clouds and some scattered showers and thunderstorms possible later in the afternoon. Overnight lows in the low-70s.

Wednesday – a cold front approaches from the west and brings us a better chance for organized showers and thunderstorms later in the day. These storms may be weakening as they hit the area if they arrive late in the day with sunlight diminishing. High temperatures again around 90ºF. Overnight lows in the low-70s.

GFS model 500 mb height, relative velocity, valid for 2PM Thursday.

Thursday behind the cold front, skies should clear up as high pressure builds. However, temperatures will remain warm in the mid-80s with downsloping westerly winds. Overnight lows around 70ºF.

NYC Father’s Day Weekend Weather – Jun 19, 2020

A slow moving low pressure and upper level low will result in the potential for isolated thunderstorms through the weekend with temperatures in the low-80s. Best chances for these diurnally driven thunderstorms would be in the afternoon hours. There’s a good amount of moisture in the air this weekend with steady southerly flow, so these storms could produce heavy rain, though severe weather is not anticipated. Past this weekend, a warmup to the mid-upper-80s (90s in interior) is forecast as upper level ridging and high pressure builds next week.

Saturday – fog early with cooler, marine flow. Temperatures warm into the low-80s with chances for scattered showers and thunderstorms particularly north and west of the city. Overnight lows in the upper-60s.

Weather Prediction Center surface forecast for 8AM Sunday

Sunday – Similar pattern to Saturday with partly sunny skies, isolated showers and thunderstorms developing later in the day particularly west of the city. Overnight lows in the upper-60s.

Monday – this pattern persists with partly sunny skies, highs in the low-80s and chances for isolated PM thunderstorms. Overnight lows in the low-70s.

GFS model 500 mb temperature, height, and wind forecast for 8PM Tuesday

Tuesday high pressure builds offshore, with upper level ridging and 500 mb temperatures increasing, we should see sunny skies and very warm temperatures nearing 90ºF. Overnight lows in the mid-70s.

NYC Weather Update – Jun 8, 2020

High pressure will be the main story this week, providing plenty of sun and summery weather. A chance for rain comes later with the extratropical remnants of Tropical Depression Cristobal. The timing of this is rain not entirely certain, but it looks like this will be Thursday for now. Temperatures this week should be ranging slightly above normal with high temperatures in the low-mid 80s.

Rest of today – mostly sunny with high temperatures around 80ºF. Just a beautiful day with comfortable temperatures and low humidity. Overnight lows in the mid-60s.

Weather Prediction Center surface forecast for 8AM Tuesday.

Tuesday – temperatures warm up into the mid-80s with lots of sun as the high pressure center shifts gradually off to the southeast and we see southerly flow take hold. Humidity still overall not that bad, so it shouldn’t feel muggy. Overnight lows in the upper-60s.

Wednesday – high temperatures back down into the low-80s though clouds could be on the increase. Overnight lows in the upper-60s with rain chances possibly increasing.

GOES visible satellite loop of Tropical Depression Cristobal the morning of June 8, 2020, after it made landfall as a tropical storm this weekend over Louisiana

Thursday a cold front associated with the extratropical remnants of Tropical Depression Cristobal could bring some rain and thunderstorms to the area. Otherwise, mostly cloudy with high temperatures in the low-80s. Overnight lows in the upper-60s.