Welcome relief from the heat today with high temperatures below normal in the 60s as cool, onshore flow sets up. The warmth returns by mid-week with highs again touching 90ºF by Wednesday. A strong thunderstorm is possible with a cold front passing through that day. Afterwards, temperatures cool but still reach above average highs in the low-80s on Thursday.
Rest of today – partly sunny with gradually increasing sun, high temperatures in the mid-60s with easterly and northeasterly winds shifting towards the southeast. Overnight lows in the mid-50s.
Weather Prediction Center surface analysis for valid 5AM Monday. Overnight, a cold front pushed southwest of the area, allowing for a much cooler air mass to take hold, with easterly onshore flow off the still as yet cold waters of the Atlantic.
Tuesday – warmer with high temperatures in the low-70s and partly sunny skies. Overnight lows in the mid-60s.
Wednesday – a warm front will pass through and put us in the warm sector of a strong low centered well to our north over Canada. Temperatures are expected to reach around the 90ºF in the city. Later in the day, as a cold front approaches, scattered but possibly strong thunderstorms could roll through. Overnight lows in the upper-60s.
GFS 850 mb temperature anomalies for Wednesday at 5PM. We are forecast to see +7ºC anomalies at this level of the atmosphere, corresponding to much above normal temperatures at the surface.
Thursday– skies clear out with high temperatures in the low-80s. Overnight lows around 60ºF.
Subtropical Storm Ana
Over the weekend, the first named storm of the 2021 Atlantic hurricane season, Subtropical Storm Ana, formed over the open waters of the Atlantic northeast of Bermuda. While the storm itself was never a threat to land, it does mark the seventh year in a row that a named storm formed ahead of the formal start of the hurricane season.
GOES satellite imagery showing the circulation of Subtropical Storm Ana
We can’t draw any conclusions from a single storm, but it is worth noting that nearly all major forecast sources including NOAA are calling for a season of above average hurricane activity.
Late April jumps into June with temperatures soaring into the 80s by midweek before a storm system approaches. This could bring us chances for rain on Thursday, while also cooling temps back to normal levels (mid-60s) by the end of the week.
Rest of today – sunny with breezy northwest winds around 20 mph. High temperatures in the low-60s. Overnight lows in mid-40s with winds diminishing as a low pressure center moves off into the Atlantic, relaxing the pressure gradient.
Weather Prediction Center surface forecast for 8AM Tuesday. A warm front will be approaching from the south. Behind this, much warmer air will be flowing clockwise around the high pressure centered off the Southeast coast of the US.
Tuesday – much warmer with high temperatures near 70ºF with sunny skies. Overnight lows in the mid-50s.
Wednesday – we will be firmly within the warm sector of the next approaching storm, and as a result, we should see temperatures rise well into the low-80s (potentially 15-20ºF above normal). This is in part due to an anomalously warm mid-upper level ridge (see below). Clouds will be on the increase as the next frontal boundary approaches. Overnight lows in the low-60s.
GFS 850 mb temperature anomalies for Wednesday at 2PM. We are forecast to see +8ºC anomalies at this level of the atmosphere, corresponding to much above normal temperatures at the surface.
Thursday– the slow moving cold front will start to impact the region with increasing chances for rain. With clouds and rain, temperatures are expected to drop back to the mid-70s. Overnight lows around 60ºF with rain chances continuining.
The week after we set our clocks back for the fall will see a shift to the coldest temperatures we’ve yet seen this season. High temperatures will trend from normal levels to slightly below normal (upper-50s to low-50s) before plummeting into the 40s following the passage of a low pressure center and cold front. The chilly air following this system will begin a longer term trend of below average temperatures going into the middle of the month at least.
Rest of today – mostly cloudy with a chance of showers as a cold front passes through later in the day. High temperatures on the mild side in the low-60s as we’ll be in the warm sector of the parent low bringing the cold front through. Overnight lows in the low-40s.
Weather Prediction center surface forecast for 7AM Wednesday
Wednesday – sunny with cooler high temperatures in the low-50s. High pressure depicted above will keep things nice and dry. Overnight lows in the low-40s.
Thursday – starting off mostly sunny with high temperatures in the mid-50s. A storm system will approach later in the day and bring the chance for rain at first, with rain and snow mixing possible overnight as lows drop into the mid-30s.
Climate Prediction Center temperature anomaly forecast for November 10-14
An anomalously low area of 500 mb heights will produce cold temperatures at the surface
Friday – the real cold sets in with high temperatures only in the low-40s. Rain/snow should taper off early giving way to sunny conditions, with winds picking up due to the low bringing this weather strengthening as it continues moving off to the northeast. Overnight lows are shaping up to be below freezing, near 30°F with winds forecast to die down and skies clearing allowing for some good radiational cooling.
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.
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 June.
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 northwest (9.5%), due northeast (9.25%), and due southwest (just below 9%). Least common wind directions are east-southeast (1%), due east (1.5%), 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, north-northwest, and due south.
Direction(s) least likely to produce the fastest winds: As is the case with several other spring 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: Wind patterns in June present a similar pattern to those in May, but with a notable increase in the frequency of winds from the southwestern quadrant, and a decrease in winds from the northeastern quadrant. This could be a reflection of shifting storm patterns, with coastal storms and backdoor cold fronts from the northeast becoming less common while more mid-latitude lows track inland north of the area, bringing more southerly warm sector flow. Persistent Bermuda highs can sometimes also develop in June over the western North Atlantic. The clockwise flow around these high pressure centers would result in more southerly and southwesterly winds. During this time of year, southwesterly winds should generally advect warmer, more humid air from the Southeastern US into the region. When this pattern becomes persistent, it can cause oppressive heat waves. Meanwhile, southerly winds (along with easterly and some northeasterly winds) would bring cooler, and more stable marine air, sometimes in the form of sea breezes. In the wake of passing cold fronts associated with mid-latitude storms, northwesterly and northerly winds, though decreasing in frequency compared to May, should still be effective at transporting cooler, drier Canadian (continential Arctic) airmasses into the area.
Maximum observed two-minute wind speed for the month: 36 (41 mph)
Temperature and Precipitation Averages/Records
Temperature units are in Fahrenheit and precipitation is in inches.
Worth Noting June is the first month of summer, and not surprisingly is also the first month of the season where record highs have exceeded 100ºF.
I’m at my college for reunion weekend, and offered to do a detailed forecast for one of the days I’m here. Saturday is shaping up to be a bit of a mixed bag. Temperatures should be summer-like in the mid to upper-80s, but the downside is a risk for possibly strong to severe thunderstorms especially in the early evening hours. These thunderstorm chances are far from being certain though, and there’s a chance we may miss out entirely on any precipitation. In other words, it’s another good day for a precipitation forecast bust!
My Forecast High: 87°F | Low: 62°F | Max sustained winds: 21 mph | Total precipitation: 0.28″ – verification will come from METAR data for the period between 2AM Saturday and 2AM Sunday (06Z Saturday to 06Z Sunday) at LPR (Lorain County Regional Airport).
Verification High: 90°F | Low: 61°F | Max sustained winds: 25 mph | Total precipitation: 0.00″ – on high temperatures, hedging up towards the higher end of guidance turned out to be a good idea. It’s yet more evidence that MOS guidance tends to be too cool for breezy warm sectors. If anything, I could have been a touch more aggressive on the high here. Did well on the low temperature, and from what I could see, did decently on max winds too. Like I’d mentioned in the forecast, the bust potential for precipitation on this day was significant. That ended up being the case – KLPR and Oberlin missed out on the heaviest rain and more serious convective activity, leading to barely a trace of measurable precipitation. In retrospect, I probably could have gone even drier with my forecast, but I would still have not felt comfortable going with zeros.
Weather Prediction Center surface forecast for 2PM Saturday
Synoptic Set Up A stationary front eventually lifts through Ohio overnight as a warm front. We’ll spend the day in the warm sector of a surface low centered over central Ontario. At the 850 mb level, winds will not be strong enough to qualify as a low-level jet and relative humidity values likewise do not appear particularly high. At 500 mb, a robust shortwave trough is forecast to push through later in the day, bringing some decent vorticity and upper-level lift. Further up at the 300 mb level, there’s not much evidence of enhanced divergence and lift since we’ll be south of a 300 mb jet streak.
GFS model output for 500 mb vorticity and winds valid at 8PM Saturday. Note the strong cyclonic vorticity values over Northeastern Ohio at this time (bright oranges). This will provide some synoptic scale lift for initiating storms via upper-level divergence.
High Temperatures GFS and NAM MOS and NBM all show Saturday to be a warm day. GFS is the warmest with 87ºF while NBM is coolest with 83ºF. EKDMOS (ensemble MOS) 50th percentile matches comes close to GFS MOS at 86ºF. Because forecast soundings show we’ll be in a well-mixed warm sector with decent though not ideal conditions for warm advection, I am tending towards thinking that a high of 87ºF is in fact possible. We could be even warmer if enough sun breaks out between possible earlier showers and rain later in the day.
GFS 2-meter temperature contours and winds at 2PM Saturday showing decent, though not ideal conditions for warm advection (southwesterly winds of 15 knots at a somewhat sharp angle across closely packed temperature contours). If surface winds were forecast to be stronger, we’d be looking at better chances for robust warm advection and hence warmer temperatures.
Low Temperatures NAM and GFS MOS are again in close agreement with 61ºF and 63ºF lows respectively. NBM is a touch cooler at 59ºF. Although both NAM and GFS show evidence of a nocturnal inversion forming, and calm winds at the surface, both models also show extensive cloudiness or even precipitation ongoing overnight. Because the boundary layer starts out with plenty of moisture, there shouldn’t be much in the way of evaporational cooling. Thus, clouds will actually serve to stave off any radiational cooling, which leads me to believe overnight lows will be on the warmer side of guidance. I’ll go with 62ºF here.
NAM MOS guidance for KLPR
GFS MOS guidance for KLPR
Max Sustained Winds NAM, GFS MOS have maximum synoptic winds averaging about 16 knots. I see no clear reasons to go much higher than 18 knots for a max sustained wind tomorrow, unless we happen have a thunderstorm roll through with sustained winds that are much higher. EKDMOS’ 50th percentile lies right around this figure. Even with well-mixed boundary layer forecast to form tomorrow afternoon, winds above the surface up to 850 mb do not appear to be that strong, only around 20-25 knots. Layer mean wind analysis of the NAM sounding only showed winds of about 16 knots.
GFS forecast sounding for 5PM Saturday
NAM forecast sounding for 5PM Saturday
Total Precipitation There’s a large spread between NAM and GFS on forecast totals tomorrow. This will be the trickiest part of the forecast because there’s clear signs that convective precipitation, with a couple rounds of possibly strong to severe thunderstorms could materialize. Any strong thunderstorm passing overhead could quickly dump a few tenths of an inch of rain. However, if we miss out on any significant thunderstorm action, we could see just a trace of rain instead. It’s still too early to tell the finer details of where storms will initiate at this point. Based on forecast soundings above, the best chance for thunderstorms to roll through would be during the late afternoon and early evening, maybe 5-8PM when moisture is best and instability is maximized from daytime heating. Strong, mostly unidirectional shear profiles with westerly winds increasing from 10 knots at the surface to 50 knots at 500 mb suggest the potential for damaging winds as the biggest severe weather threat.
NAM forecast for 850 mb winds and relative humidity at 2PM Saturday
GFS forecast for 850 mb winds and relative humidity at 2PM Saturday
Going against the potential for significant precipitation, neither GFS nor NAM really show strong signals of low-level jet support. Winds at the 850 mb level don’t look to be particularly strong, and moisture support isn’t looking great either. What’s more, while there’s mention in the local forecast office discussion of a right entrance region of an upper-level jet that would provide some dynamic lift, I’m not seeing that myself. They did also mention that a trough would pass through and provide a focus for some lift. This would be a necessary trigger since there’s no clear frontal boundaries that would provide the convergence and lift necessary to generate showers and thunderstorms. Given the hit or miss nature of thunderstorms, less than ideal conditions for heavy precipitation, and disagreement between GFS and NAM MOS at this time, I find it prudent to hedge down with a forecast for 0.28″ of total precipitation despite MOS guidance averages at 0.48″.
The long holiday weekend appears to be mainly dry, and even features a day that could make for a good beach getaway. We do have a chance for rain overnight Saturday into Sunday but this shouldn’t be a damper on anyone’s plans. Sunday’s shaping up to be the warmest day of the weekend although Memorial Day itself may end up being the nicest all around day.
Rest of today – breezy and sunny with high temperatures in the mid-70s. The strong pressure gradient between a departing surface low and a high pressure center moving east from the Great Lakes is what’s causing these breezy conditions. Winds should die down overnight as the high moves overhead and the pressure gradient relaxes. Overnight lows in the upper-50s.
Weather Prediction Center surface forecast for 8PM Friday
Saturday – as the high pressure continues moving east, clouds will increase due to the influence of an advancing warm front. This frontal boundary may serve as the focus for some showers and thunderstorms overnight Saturday into Sunday. High temperatures Saturday expected to be in the low-70s due to increasing cloud cover. Overnight lows in low-60s.
GFS model output for surface pressure, precipitation, 500 mb thickness valid 4PM Sunday
Sunday – we’ll be in the warm sector this day. Clouds and rain are expected to subside early and allow for temperatures to warm into the mid-80s and possibly higher. This will be the best day of the weekend to hit the beach though it’s not a lock for sunny weather all day. Overnight lows in the mid-60s.
Monday (Memorial Day) – anticipating this will be the best day of the weekend with sunny skies and mild temperatures in the upper-70s. Overnight lows in the low-60s.
This weekend is shaping up to be similar to last weekend in some respects, with Saturday being a nearly ideal day with plenty of sun, while Sunday is cloudier with some chance for rain. The big difference is unlike last weekend, we’re not anticipating a coastal storm or record-breaking cold! In fact, we should see our first 80°F+ day in some time by Monday before a chance for showers and thunderstorms cools things off.
Rest of today – current visible satellite observations show clouds moving in from the west, so the sunny start to the day will give way to mostly cloudy conditions later. Temperatures will be mild with the influence of warm southwesterly winds, topping out in the mid-70s. Later in the evening, a cold front will push through, bringing a chance for scattered showers and possibly a thunderstorm or two. Overnight lows expected in the mid-50s.
Weather Prediction Center surface forecast for 2PM today
Saturday – even though we’ll have a cold front push through, sinking air behind the cold front and downsloping winds from higher terrain in the north should keep things around average for this time of year in the low-70s with mostly sunny skies. Overnight lows continue to be in the mid-50s.
NAM output for 500 mb height and vorticity, valid for 8AM Saturday. A noticeable reversal of the upper air pattern from earlier this week is visible with a deep longwave trough over the Western US, and ridging over the Eastern US. This will result in great weather for us tomorrow, while areas of the Plains downstream of the trough picture above see the potential for severe weather.
Sunday – warm front approaching from the south during the day Sunday will result in more clouds than sun, and perhaps a scattered rain shower. High temperatures still around average for this time of year in the low-70s. Overnight lows warm up into the low-60s as we enter the warm sector of the storm system approaching us from the west that’s expected to bring severe weather to parts of the Central US this weekend.
Monday – with the region forecast to be in the warm sector of the parent low shown below, and a prolonged period of southwesterly surface winds bringing warm air into the area, temperatures are expected to warm up into the low-80s. This day will have a summery feel, with some humidity to the air and a chance for showers and thunderstorms later in the day as a cold front approaches from the west. Overnight lows should remain mild around 60°F.
Weather Prediction Center surface forecast for 8AM Monday
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 May.
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: The most common wind direction for this month by frequency of occurrence is due south (~13%).
Directions that are most and least common: Due northeast (11.5%) winds present a second maximum of most frequent winds. The least common wind direction is east-southeast (~2%), followed by due east (~2.25%).
Direction(s) most likely to produce the fastest winds: Due northwest winds have a slim possibility of generating winds over 21.5 knots. No other wind direction seems to have a measurable occurrence of winds exceeding this speed. This is a marked difference from the previous two months when wind speeds of this magnitude were much more common. Winds of 16.5-21.4 knots are most frequently found coming from the west-northwest, due northwest, north-northwest, and due south.
Direction(s) least likely to produce the fastest winds: Due east, east-southeast, and due southeast winds rarely exceed 16.4 knots.
Impacts of wind direction on local weather: The most common wind directions in May differ from the previous two months, with northwesterly winds becoming less frequent, while southerly and northeasterly winds become more prominent. In fact, winds from the southern semicircle are generally more common than previous months. Cold air advection from northwest winds continue to influence temperatures in the wake of cold fronts approaching from the west, however, the effect should be dramatic than in prior spring months. Winds from the northeast can be associated to backdoor cold fronts arriving from the Canadian Maritimes, bringing a moist, cool maritime polar air mass; the advance of coastal Nor’easter type storms; or a warm front approaching from the south. The difference between sea surface temperatures and temperatures over land widens during May as daily normal highs increase. This increases the chances for sea breezes during periods of overall weak synoptic winds, though generally, southerly winds would allow for advection of warmer, more moist airmasses into the area. This would often be the case when the NYC region is in the warm sector of mid-latitude lows, preceding the passage of a typical cold front attached such lows.
Maximum observed two-minute wind speed for the month: 36 (41 mph)
Temperature and Precipitation Averages/Records
Temperature units are in Fahrenheit and precipitation is in inches.
Worth Noting: Average temperatures climb above 70ºF in May for the first time during the spring months. In 2019, new record lows were set for the 13th and 14th of May, at 42ºF and 44ºF respectively. In 2020, an all-time monthly record low of 36ºF was set on May 9th. In 2021, record lowest max temperatures were set for the 29th and 30th (52ºF, brrr), and record lows were set for the 29th-31st (48ºF, 48ºF, and 50ºF respectively)!
This weekend will see a warm start but then a cool down into the below normal range going into next week. A rumble of thunder and showers will precede this cool down. Weather looks pleasant for St. Patrick’s Day festivities and the NYC Half Marathon this weekend.
Rest of today – mostly cloudy with some breaks of sun after a warm front passes over shortly and we sit in the warm sector of the same storm that tore through the central US earlier this week. As the trailing cold front pulls through this evening, it could provide enough lift for some additional showers and possibly a couple thunderstorms. High temperatures will be above average in the low-60s, mid-60s if some sun breaks through while we’re in the warm sector. Overnight lows behind the cold front should be in the low-40s.
Weather Prediction Center surface forecast for 8PM Friday
Saturday – bright, sunny day with high pressure building behind the cold front. Temperatures cooler, around 50°F. Overnight lows much cooler in the low-30s.
Sunday – cold start to the NYC Half Marathon in the low-30s but high temperatures will end up in the mid-40s with lots of sun. Overnight lows again around the freezing mark
Monday – increasing clouds with a possibility for some precipitation but chances are too low now to call. Highs in the mid-40s and overnight lows back down in the low-30s again.
