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.
GFS 850 mb temperature anomalies for 2PM Monday
Weather Prediction Center surface forecast for 8PM Tuesday.
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.
While it looked earlier this weekend that this would be a rainy week, it now appears that strong high pressure will keep two storm systems largely at bay. One of these will be the post-tropical remnants of Tropical Storm Arthur that formed this weekend. The tradeoff is that this high of Canadian origin will bring cooler than normal temperatures in the 60s. This pattern breaks up by late this week, yielding warmer temperatures in the 70s by this weekend.
Rest of today – mostly cloudy though no rain expected with high temperatures around 70ºF. Clouds from the two storm systems below will remain throughout the day. Overnight lows in the mid-50s as skies gradually clear.
In this GOES geocolor visible satellite loop, you can clearly see two centers of circulation – one over the Midwest associated with a maturing mid-latitude cyclone, and one over the Atlantic – Tropical Storm Arthur.Weather Prediction Center surface forecast for 8AM Tuesday.
Tuesday – high pressure continues building, and blocks the northward and northeastward progress of both storms. Temperatures cool into the mid-60s despite more sun with northeasterly onshore winds. Tropical Storm Arthur is expected to have undergone extratropical transition by this point, and potentially strengthened due to baroclinic forcing. The proximity of this storm to the high pressure will produce a tight pressure gradient resulting in stronger winds during the day Tuesday. Overnight around 50ºF.
Wednesday – high pressure remains in place, producing sunny skies. High temperatures still cooler than normal in the mid-60s. Overnight lows in the mid-40s.
Climate Prediction Center temperature outlook for May 23-27: temperatures appear ready to rebound going into this weekend to above normal levels.
Thursday– sunny with high temperatures in the mid-60s still. Overnight lows in the low-50s.
Record setting cold this weekend that led to rare May snows will feel like another life time by the end of this week when temperatures will soar to near or above 80ºF. A general warming trend will take place until then, bookended by rain chances today and Friday due to a couple passing storms.
Rest of today – mostly cloudy with hig temperatures in the upper-50s. A fast moving storm could bring scattered showers and thunderstorms later this afternoon. Overnight lows in the low-40s as skies clear.
Weather Prediction Center surface forecast for 8AM Tuesday.
Tuesday – sunny high pressure building, high temperatures in the upper-50s. Overnight lows in the low-40s.
Wednesday – high pressure steadily moves east, bringing another day of sunny skies and high temperatures in the low-60s. Overnight lows in the mid-40s.
Climate Prediction Center temperature outlook for May 16-20, finally, it looks like we get a break from below normal temperatures!
Thursday– high temperatures warm into the mid-60s with high pressure still in control giving us mostly sunny skies. Overnight lows in the mid-50s.
April ended with another stormy week with plenty of rain. May starts of grey Friday, followed by a spectacular day Saturday. Rain enters the picture again Sunday. Behind this next storm system, things will cool off again. This will lead temperatures to continue their cool trend throughout most of next week. During this period high temperatures will range at least 5ºF below the upper-60s that are normal for this time of the year.
Rest of today – the slow moving storm that began impacting us yesterday continues to influence weather today. Scattered showers wrapping around the backside of the low responsible for this storm could still occur. Temperatures should generally be in the low-60s with mostly cloudy skies otherwise. Overnight lows in the low-50s as the storm finally exits.
Weather Prediction Center surface forecast for 8AM Saturday
Saturday – high pressure builds in behind this storm, bringing the best day of the frorecast period with high temperatures expected to top out around 70ºF under sunny skies. Overnight lows in the mid-50s.
Sunday – just like last weekend, the sunny, dry weather barely lasts before the next storm moves in. This will be a weaker, and faster moving storm so rain should be on the lighter side. Currently expecting most of the day Sunday to be dry with clouds building and high temperatures still warm in the low-70s. Overnight lows in the mid-50s.
Monday– once this low clears our region, winds shift to the north and a cooler air mass works its way in. Skies clear with temperatures falling back the low-60s. Overnight lows only in the upper-40s. This cool trend looks set to continue for the duration of next week. Though after a week with high temperatures in the 50s, the low-60s looks pretty good.
Climate Prediction Center temperature outlook for May 6-10. Below average temperatures are indicated as very likely for much of the Eastern US
This temperature trend is borne out in the GFS models 2-meter above ground level temperature anomalies. This chart is valid for 8AM Tuesday
An active weather pattern brings yet another week of cool, rainy weather. Tuesday will be the only day with sunny skies and near normal temperatures with high pressure briefly building in. Otherwise, a couple slow moving storms will bring clouds and rain the rest of the week. This will result in temperatures largely running below seasonal averages. I suppose that’s some incentive for people to stay safe and quarantine at home?
Rest of today – early rain chances should diminish steadily. High temperatures cool, only around 50ºF under the influence of northerly flow as the slow moving coastal storm that impacted us yesterday and today moves off to the northeast. Clouds should start to diminish later in the day. Overnight lows in the low-40s.
NAM output forecast cloud cover for 11AM Tuesday
Tuesday – we should see a brief window of sunny skies and dry weather as high pressure builds and passes over for the day. This break in rainy weather should allow temperatures to climb into the low-60s. Overnight lows in the mid-40s.
Wednesday – the reprieve from dreary conditions barely lasts a day as yet another storm system takes aim at the area. With the high pressure Tuesday slow to move east, this next storm will be similarly as slow moving as this past weekend’s storm. The result for Wednesday, even if we don’t get too much in the way of rain, will be cloudy conditions and cool, southeasterly onshore flow ahead of an advancing warm front. This will cause temperatures to cool into the mid-50s. Overnight lows barely budge, and hover around 50ºF.
Weather Prediction Center surface forecast for 8AM Thursday
Thursday– the second storm of the week hits with steady rain and southeasterly onshore breezes. Warm advection could help temperatures stay slightly above 60ºF, with overnight lows in the low-50s.
A couple storm systems will impact NYC this week. The first of these could bring some thunderstorms and gusty conditions tomorrow afternoon. Later this week on Thursday, a second storm bringing steadier rain will move through. Temperatures throughout this period will be generally 5ºF below normal. Tuesday and Wednesday overnight lows could bottom out in the upper-30s.
Rest of today – mostly cloudy, with clouds diminishing later, high temperatures in the upper-50s. Overnight lows in the mid-40s.
Weather Prediction Center surface forecast for 8AM Tuesday
Tuesday – quick moving storm will push a warm front and then a strong cold front through Tuesday afternoon. Showers should begin in the afternoon and a line of thunderstorms is possible with the cold front. High temperatures around 60ºF with southwesterly flow ahead of the cold front. Overnight lows in the mid-30s.
Wednesday – the low bringing the rain and thunderstorms on Tuesday continues to strengthen. The pressure gradient will tighten around this low and bring windy conditions but with sunny skies. High temperatures cool off into the low-50s. Overnight lows in the upper-30s.
GFS 2-meter above ground level temperature anomalies for 2AM Thursday. A cold night in store for many parts of the Northeast!
Thursday– partly sunny skies with high temperatures climbing into the upper-50s. Overnight lows around 50ºF with rain developing.
The groundhogs were unanimous in their proclamation of an early spring, but do their predictions jive with climate forecasts? Either way, the first week of February will be an active one with multiple storms impacting the area. Temperatures are forecast to start much above normal in the mid-50s, then taper down to being a touch above normal in the low-40s. Most of the precipitation that falls should be in the form of rain, though overnight periods could produce mixed precipitation.
Rest of today – Early clouds should give way to more sunny skies later in the day. High temperatures will be mild, in the mid-50s as a stationary front slowly lifts north as a warm front into the overnight hours. Overnight lows in the low-40s.
Tuesday – High temperatures in the low-50s. The warm front mentioned above stalls out, then returns as a cold front. This pattern brings the potential for some light rain showers. Overnight lows in the low-40s.
Wednesday – high pressure builds in briefly, and should give us some reprieve from rain, however, north winds will cool things off with highs in the low-40s. Overnight lows drop into the low-30s as a second, stronger storm system takes aim at the area. This one could start off as wintry mix and sleet overnight for NYC.
Thursday– any accumulation of wintry mix should get washed away as this second storm system lingers and produces rain during the course of the day Thursday. Mostly cloudy otherwise as highs climb into the low-40s. Temperatures currently forecast to remain steady for the most part overnight with onshore flow.
Are the Groundhogs Right? Climate Prediction Center’s temperature outlooks for the second half of February and the entire month suggest that the groundhogs might be on to something – at least for the eastern part of the US (especially the southeast), where above normal temperatures are being forecast. That isn’t as much the case for the western US, as you can see below.
Climate Prediction Center temperature outlook for Feb 8-12
Climate Prediction Center temperature outlook for Feb 10-16
Climate Prediction Center temperature outlook for the whole month of February
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 February.
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 northwest (14.25%), same as with January.
Directions that are most and least common: Other most common wind directions include west-northwest (11.25%), due northeast (10.5%), and north-northeast (9.5%). Least common wind directions are east-southeast (0.5%), due east (1%), and south-southeast (1.25%).
Direction(s) most likely to produce the fastest winds: As is the case with other cold weather months, winds in excess of 21.4 knots (~25 mph) are most frequently found coming from due northwest. West-northwest, north-northwest, and due northeast winds can also produce winds over 21.4 knots though less frequently.
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: February wind patterns are remarkably similar to January. Winds from the northwestern quadrant remain prominent. These directions also continue to produce the strongest winds. Interestingly, due northeast winds pick up in frequency in February compared to January.
Northwesterly winds bring cooler, drier Canadian air into the region following cold fronts. Winds from this direction also occur on the backside of departing coastal lows. Winds from these directions downslope coming off the higher terrain of the Catskills, and Poconos outside of the city. This can sometimes lead to warmer temperatures than would normally be expected for this wind direction as well as faster wind speeds. As with other months, northeasterly winds are usually related to backdoor cold fronts sweeping from the Canadian Maritimes, the onshore flow ahead of an advancing warm front, or a passing coastal storm to the south.
Maximum observed two-minute wind speed for the month: 39 knots (46 mph).
Temperature and Precipitation Averages/Records
Temperature units are in Fahrenheit and precipitation is in inches.
Worth noting: February average high and low temperatures start the a slow upward trend that will carry through to the spring and summer. Amazingly, record high temperatures in February can top 70°F, even nearing 80°F.
Lunar New Year day in New York city will see the passage of a relatively robust storm system. Ahead of this storm, persistently easterly onshore winds could result in some minor coastal flooding. A band of moderate to heavy rain looks like it will sweep through in the afternoon hours. Rain should clear up quickly by the early evening. Temperatures should be above normal with some warm air advection.
My Forecast High: 49°F | Low: 38°F | Max sustained winds: 26 mph | Total precipitation: 0.85″ – verification will come from METAR data for the period between 1AM Saturday and 1AM Sunday (06Z Saturday to 06Z Sunday) at LGA (LaGuardia Airport), and the KLGA Daily Climate Report.
Verification High: 52°F | Low: 38°F | Max sustained winds: 30 mph | Total precipitation: 0.78″ – all around this wasn’t too bad of a forecast. Wind speeds were slightly higher, and coming from the southeast. This could help explain why temperatures broke into the low-50s as this set up would have produced better warm air advection. Got the low temperature spot on. As for precipitation, at first I thought this was going to be a bust because the storm seemed to be moving faster than model data suggested. However, even with rain stopping by around 4pm, enough moderate to heavy rain fell that we went above 0.75″, though not too much over. I’m glad I didn’t buy into a higher precipitation total than 0.85″!
Weather Prediction Center surface forecast for 7AM Saturday
Synoptic Set Up A primary occluded low tracking over the Great Lakes will spawn a secondary coastal low at the triple point between its occluded, warm and cold fronts. The primary low should weaken as it becomes vertically stacked with a 500 mb closed low (depicted below) and slowly consolidate with the secondary low. During the day, the secondary low is forecast to track northeast with the triple point tracking almost directly over NYC by around 7PM.
Ahead of this, we could see some light rain due to isentropic lift north of the surface warm front. Strong lift is expected as the low/triple point tracks closer, and lift will be enhanced by favorable conditions at 300 mb and 500 mb levels. At the 500 mb level, the aforementioned closed low is forecast to cause ample downstream positive vorticity resulting in increased divergence. Further up at the 300 mb level, it appears the left exit region of a powerful jet streak over the Southeastern US will lie south of us, and we’ll be under the right entrance region of a smaller, weaker jet streak. Both these regions will produce increased divergence and enhance lift. SREF probabilities for moderate to strong omega > -6 mb/sec were in the 50%-70% range.
High resolution models suggest a narrow band of moderate to heavy rain during the afternoon hours. A significant low-level jet at 850 mb with winds 45-55 knots and will aid with transporting subtropical moisture northwards. A dry slot works in quickly behind the primary slug of moisture by 7PM – this should cut off precipitation for the most part.
NAM 500 mb heights and vorticity valid 4PM Saturday
NAM forecast 300 mb heights and wind valid 1PM Saturday
High Temperatures Statistical models were in decent agreement, with NAM being the coolest coming in at 46°F. GFS was closer to 50°F and EKDMOS 50th percnetile was 49°F. Erring on the side of being cautious about going warmer than 50°F because of of the proximity of the triple point. If that tracks offshore more, we’d see a switch to westerly winds sooner and would end up being in a cooler airmass. Rain and clouds will also keep things in check. There’s some warm air advection indicated, but also need to keep in mind that sea surface temperatures are only in low-40s offshore around NYC. For these reasons, went the EKDMOS 50th percentile at 49°F.
Low Temperatures The surface and near surface layer start off pretty dry. Evaporational cooling as the column saturates could have potential to keep temps on the cool side. EKDMOS 50th percentile was steady across two runs at 39°F. Statistical models had a spread from NBM at 36°F to GFS with 42°F. I’m going with 38°F because I think evaporational cooling will be a factor overnight.
NAM MOS forecast for KLGA
GFS MOS forecast for KLGA
Max Sustained Winds Seems like winds will mostly driven by synoptic factors, since I don’t see signs of a well-mixed surface layer. However, downard momentum transfer with heavy rains could help bring some of the very fast 850 mb winds to the surface. It’s not hard to imagine sustained winds in excess of 20 knots. Winds coming from the east-northeast and east will be off the water towards LGA, with decent fetch over open water, so edging towards a higher max wind of 26 mph. This matches EKDMOS 50th percentile and is higher than GFS and NAM statistical guidance of 16 and 19 knots respectively.
NAM forecast sounding for KLGA valid 1PM Saturday. The atmospheric column is saturated throughout by this point (dew point temperature in green and environmental temperature in red overlap), meaning precipitation is ongoing. Also note how strong winds are throughout the column.
Total Precipitation Strong lift will accompany the triple point as stated above. A low-level jet is also forecast to set up, creating conditions conducive for heavy rain. However, development of a dry slot is apparent in the early evening – this would put the brakes on precipitation. If that dry slot moves through earlier, bust potential for higher end total precipitation amounts is there. Statistical guidance ranges 0.60″-0.75″ on the low end, up to 1.23″-1.48″ (which would be record-breaking) on the high end. Various ensemble means range from 0.77″-0.94″, which is on the low end of the statistical guidance. Ensembles also showed a fairly tight spread, indicating decent confidence. The ensemble plume mean is close to the average mean of statistical guidance around 0.85″. This seems reasonable as it allows for possibility of heavy rain while still falling squarely within predicted ranges for both statistical and ensemble guidance. SREF probabilities for > 1.00″ of total precipitation aren’t a lock (10%-50%) with a very tight gradient southeast.
The weather story for this weekend in NYC will be the near record-breaking warmth we’ll have with temps at or above 60°F Saturday and Sunday. A storm system sweeps through overnight going into Sunday, and should clear by Sunday afternoon. Behind this, temperatures will drop back to the upper-40s, which is still almost 10ºF above normal for this time of the year! Enjoy this rare occurrence of near record warmth that isn’t accompanied by a washout.
Rest of today – mostly cloudy with high temperatures in the low-50s. A strong area of high pressure offshore southeast of our area will be steadily pumping warm, moist air into the region. Looking at the chart below, you’ll see southerly winds blowing at large angles across temperature contours that increase going south – this is an ideal set up for persistent warm air advection and will set the stage for the warmth we see this weekend. Overnight lows in the mid-40s. With moisture advecting into the area, we could see areas of fog develop overnight.
GFS 2-meter temperature with contours and 10-meter wind barbs.
Saturday – very mild with temperatures in the low-60s. Mostly cloudy with a southerly breeze and some fog possible. Overnight lows in the mid-50s. Rain chances increase particularly late overnight going into Sunday morning.
Sunday – elevated convection could bring a rumble of thunder Sunday morning, with rain chances peaking in the early morning hours. High temperatures should remain quite mild, in the mid-60s (and possibly higher with downsloping westerly winds for a period with clearing skies, following the passage of a prefrontal trough and before a cold front closes in). Overnight lows dropping into the low-40s – which is actually still above normal for what a daytime high temperature should be this time of year.
NAM high resolution model output of 1000-500 mb thickness, surface pressure, and precipitation valid for 5AM Sunday
Monday– high temperatures similar to Friday near 50ºF, partly sunny skies. Overnight lows in the low-30s.
