Monthly Archives: March 2019

NYC (KLGA) Climatology for March

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. As such, I’ve decided to post some critical components of climatology for the closest station to me, LaGuardia Airport (KLGA). Below, I’ve posted some general climate data, and also specific data for the month of March.

Other Month’s Climatologies

January
February
April
May
June
July
August
September
October
November
December

Station Basic Information

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.

Topographical map of New York State

Per the Local Climatological Data report from the National Weather Service:

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.

March wind rose for KLGA, source: National Resource Conservation Service

Frequency (percentage) of the single most common wind direction: Due northwest occuring about 14% of the time.

Directions that are most and least common: Most common wind directions following due northwest are due northeast (11.75%), west-northwest (10.25%), north-northwest (8.5%). Least common wind directions are east-southeast (1%), due southeast (2%), and due east (2.25%).

Direction(s) most likely to produce the fastest winds: The most common wind directions are also the ones most likely to produce the fastest winds.

Direction(s) least likely to produce the fastest winds: Again, the least common wind directions are also least likely to produce the fastest winds.

Impacts of wind direction on local weather: Prevalent northwesterly winds during this month generally follow in the wake of cold fronts and coastal storms. These winds can lead to substantial cold air advection (transport of cold, dry continental polar air mass from interior Canada), often because of subsidence in the wake cold fronts mixing down very fast winds to the surface. These winds will downslope and warm slightly as they approach the coast though. A secondary maximum of winds from the northeast can be attributed to backdoor cold fronts arriving from the Canadian Maritimes, bringing a moist, cool maritime polar air mass, or in conjunction with the advance of coastal Nor’easter type storms. During March, sea surface temperatures in the vicinity of NYC are above freezing, but by no means warm. If a warmer air mass is in place prior to winds shifting to the northeast, cooler, more moist conditions will result. If a colder, below freezing air mass is present, northeasterly winds can exert moderating influence on temperatures. Persistent northeasterly winds can also lead to the potential for coastal flooding given the shape of local coastline.

Maximum observed two-minute wind speed for the month in knots: 40 knots (46 mph).

Temperature and Precipitation Averages/Records

Temperature units are in Fahrenheit and precipitation is in inches.

Worth Noting: Average temperatures in March rise above 50°F for the first month since November. However, March can certainly still produce cold days – many of the record lowest max temperatures are below freezing, with record lows still in the teens and single digits. It is a month indicative of spring when large temperature swings are possible.

DateNormal HighNormal LowRecord HighRecord LowRecord Lowest MaxRecord Highest MinNormal PrecipRecord Precip
1453171825530.122.23
24631671325500.112.44
34631651025490.122.26
4463169725460.111.53
5463272925480.120.72
64732641424480.122.47
74732691425490.131.90
84732741428540.121.20
94733751426490.122.18
104833781227620.121.52
114833701530490.121.40
124833691528490.121.83
134934831933530.123.15
144934751834500.121.41
154934741429480.131.61
165034771932510.131.12
175035741526540.131.39
185035751319510.142.05
195135721026530.131.38
205136821931530.141.18
215136701834530.142.00
225236761933540.133.15
235237741926560.141.44
245237741730500.141.63
255337771832500.131.55
265338722034510.141.26
275438832336540.141.20
285438832336580.132.83
295439862534590.141.90
305539792334590.132.65
315539822436590.142.10
Range45-5531-3964-867-2519-3645-620.11-0.140.72-3.15





NYC Weekend Weather – Mar 1, 2019

Although the calendar has flipped to March and we’re less than 3 weeks from the official start of spring, the weather has taken a decidedly winter-like turn as of late. This pattern will continue over the weekend and into next week. Initially, we’ll contend with 2 coastal storms that will bring chances for snow, and then enter next week with temperatures well below normal for this time of year. Sadly, this colder than normal pattern looks locked in for the next week or more

Rest of today – overcast conditions with temperatures hovering in the mid-30s. Precipitation will move back into the area by later this evening. Thermal profiles overnight point to a mix of snow/sleet at the coast with lows just around freezing. The local forecast office calls for an accumulation of 1-2″ of this wintry mess.

Weather Prediction Center surface forecast for 7AM Saturday

Saturday – the wintry precipitation continues the first half of the day as the first of two coastal storms continues to impact the region. High temperatures should warm up to around 40ºF with mostly cloudy skies, and precipitation should die off later in the day. Overnight lows should be around freezing.

Sunday – starts off as a decent enough day, but a second storm will be brewing and moving offshore, impacting the area overnight into Monday. High temperatures should be similar to Saturday in the low-40s with partly sunny skies. At this point, the primary precipitation modes at the coast appears to be a rain/snow mix. Thermal profiles don’t appear cold enough to support all snow with overnight lows expected to be above freezing around 35ºF.

Global Forecast System 1000 mb – 500 mb height, pressure, thickness foreast for 6AM Monday

Monday – precipitation tapering off early in the morning as this storm is a fast-mover. Temperatures topping out in the upper-30s with mostly cloudy skies.

Colder than Normal Temperatures Ahead

Climate Prediction Center has a 6-10 day temperature outlook suggesting a colder than normal pattern for much of the country, including our area. During this time, the polar jet stream is expected to dip further south allowing colder air to penetrate into the Continental US.