Near record warmth to start the week in the upper-60s to low-70s. A summer-like pattern with a strong high pressure center over the western Atlantic will keep warm, southerly winds coming our way. A cold front will approach Tuesday bringing chances for rain. Temperatures remain above normal in the 50s for the remainder of the week.
Rest of today – very warm with mostly sunny skies and highs in the upper-60s to low-70s. The record high for today at LGA is 75°F so this is definitely abnormally warm. Strong ridging over the western Atlantic is leading to very warm southerly flow coming our way. Overnight lows in the upper-40s.
Tuesday – an approaching cold front will bring clouds and some chances for rain especially later in the day. High temperatures will still be quite mild in the low-60s with continuing southerly flow ahead of the frontal passage. Overnight lows should be in the mid-40s.
Wednesday – behind the cold front, temperatures will dip into into the mid-50s, but that’s still 7-10ºF above normal for this time of year. Skies should also clear up. Overnight lows will drop into the low-40s.
Climate Prediction Center temperature outlook for Mar 14-18, showing the above average temperature trend continuing in many parts of the Eastern US while below normal temperatures are likely out west.
Thursday– similar day to Wednesday with high temperatures in the mid-50s, but with potentially more clouds as the next storm system approaches. Overnight lows in the low-40s.
First half of this week features much above average temps in the upper-50s slowly dropping to the low-50s after mid-week. A passing storm system could bring showers and isolated thunderstorms overnight tonight. Temperatures remain mild until later in the week. Another chance for rain/snow is possible overnight Friday into Saturday as another storm system passes by.
Rest of today – very mild, high temperatures in the upper-50s with the area in the warm sector of a low pressure system centered over northern Quebec. A secondary low will bring another reinforcing warm front through before the trailing cold front finally swings through. Rain chances increase towards the afternoon with a batch of rain possible around 3PM. A second, stronger round of rain is possible around 10PM. Overnight lows in the mid-40s.
Weather Prediction Center Surface forecast for 1AM Wednesday
Wednesday – despite the passage of a cold front, the air mass behind the front won’t be that much colder than today’s. Furthermore, downsloping westerly flow should keep things on the mild side with high temperatures expected in the mid-50s under mostly sunny skies. Overnight lows will dip into the upper-30s.
Thursday – another nice day with high temperatures still above normal in the low-50s, with mostly sunny skies. Overnight lows in the upper-30s.
Climate Prediction Center temperature outlook for Mar 8-12, showing a warm up yet again next week.
Friday– clouds build as a couple storm systems start making their way towards our area. Cloud cover and chances for rain during the day will keep temperatures closer to normal in the mid-40s. Overnight lows in the low-30s could allow for some rain to mix with snow before the storms clear our area.
Mild temperatures from this weekend carry over into the beginning of this week. High temperatures will remain in the 50s, well above normal, until the second half of the week. A couple storm systems will impact the area bringing rain, as well as a cool down in temperatures to end the week. The upcoming weekend will see temperatures drop to below normal levels with highs only in the 30s.
Rest of today – very mild, high temperatures in the upper-50s with persistent southerly flow. Increasing clouds towards the overnight hours. Rain chances increase towards day break with overnight lows in the low-40s.
Weather Prediction Center surface forecast for 7AM Tuesday
Tuesday – rain chances continue to increase as the storm above moves closer. High temperatures top out in the low-50s with mostly cloudy skies and rain chances throughout the day. Overnight lows in the low-40s with rain chances continuing.
Wednesday – rain starts to diminish but is still possible with this storm system being fairly slow to clear the area. High temperatures remain in the low-50s. Overnight lows in the mid-40s with one more slug of rain moving through.
GFS mean sea level pressure, and 10 meter above ground winds for 11PM Thursday
Thursday– clouds start to break and the rain finally clears the region. Winds will pick up as high pressure builds to the west with low pressure exiting east, creating the right pressure gradient depicted above. High temperatures dropping into the upper-40s. Overnight lows in the low-30s with cooler northwesterly winds.
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.
This weekend coming up will see a dramatic contrast from last weekend’s record-breaking warmth. Temperatures during the next few days will be average to below normal. Overnight lows in the low-20s for this period. A “warm up” will happen as we enter the warm sector of a passing storm Saturday going into Sunday, but reinforcing cold air arrives to start next week.
Rest of today – partly sunny with strong northwesterly winds. Temperatures will drop from around 50ºF into the low in the mid-20s overnight. A trough extending west from a departing area of low pressure that’s bringing the strong winds may touch off some rain.
Friday – a cold, sunny day with high temperatures starting off in the low-20s and only expected to reach 30ºF under the continuing influence of northwesterly winds .
Saturday – a large storm system will move through. Temperatures starting off in the low-20s will warm into the upper-30s with southerly flow ahead of the main cold front associated with this low. Thermal profiles will support snow to start, with a light accumulation possible before temperatures warm enough at the coast to transition to all rain overnight. Overnight lows aren’t expected to move much, dropping into the mid-30s.
GFS model 500 mb height anomalies for 7AM Monday
GFS model 300 mb heights and winds for 7AM Monday – the orientation of the jets stream mirrors the position of 500 mb height anomalies
Sunday– improving conditions with high temperatures in the upper-30s and partly cloudy skies. Overnight lows in the low-20s as a second and stronger blast of Arctic air flows in behind Saturday’s storm.
A quiet, though colder than normal week lies ahead after the departure of Monday’s storm. This storm ended up not bringing the city much of any accumulating snow, though the story was quite different further north. High pressure settles in briefly before a weaker disturbance affects the area later in the week. An arctic front passes Friday, bringing a reinforcing shot of cold. Temperatures during this time will range in the low-40s.
Rest of today – mostly sunny with high temperatures in the low-40s. Winds diminishing as the low that hit us yesterday continues to pull away to the northeast. Overnight lows around the freezing mark.
Weather Prediction Center surface forecast for 7PM Wednesday
Wednesday – partly sunny with high temperatures in the low-40s. Overnight lows in the mid-30s.
Thursday – mostly sunny with high temperatures in the low-40s, and overnight lows in the low-30s.
Climate Prediction Center temperature outlook for next week. A warm up is coming after this week of below normal cold.
Friday – mostly sunny with high temperatures in the low-40s and overnight lows in the mid-20s behind the passage of a dry Arctic front.
Thanksgiving week starts off with warmer than average temperatures largely in the mid-50s ahead of an approaching storm that should impact the area Wednesday. Behind this storm, temperatures are forecast to drop back into the 40s. Thanksgiving Day will be dry, however, the low responsible for the mid-week storm will deepen as it exits the region, resulting in winds possibly strong enough to ground the Macy’s Thanksgiving Day Parade balloons.
Rest of today – partly sunny with high temperatures in the low-50s. Overnight lows heading down into the low-40s with mostly clear skies overnight.
GFS model 500 mb height anomalies, showing positive anomalies over much of the Northeast on Tuesday
Tuesday – southwesterly flow ahead of an approaching cold front/storm system should allow temperatures to warm into the mid-50s. Overnight lows in the mid-40s.
Wednesday – cloudy with high temperatures in the mid-50s. Chance of showers during the day and into the early overnight hours. Decreasing clouds overnight, with lows in the mid-40s and increasing winds.
GFS model output for 1000-500 mb heights, surface pressure, and precipitation
Thursday – mostly sunny with high temperatures around 50°F, winds should be quite breezy with a tight pressure gradient forming around the deepening and exiting low pressure center. Overnight lows in the mid-30s.
Thursday will probably end up being the best day of the week. High pressure will be in control from most of the period allowing for a sunny day with seasonable temperatures. Winds may be stiff overnight as well as late Thursday night into Friday. Rain associated with a low pressure system moving in will hold off until Friday.
My Forecast High: 50°F | Low: 38°F | Max sustained winds: 20 mph | Total precipitation: 0.00″ – verification will come from METAR data for the period between 1AM Thursday and 1AM Friday (06Z Thursday to 06Z Friday) at LGA (LaGuardia Airport), and the KLGA Daily Climate Report.
Verification High: 53°F | Low: 39°F | Max sustained winds: 14 mph | Total precipitation: 0.00″ – high temperatures ended up being a bit warmer than expected, more towards the EKDMOS 90th percentile range. I think this had to do with the fact that overnight lows were warmer (did a good job edging up on that), and because northwesterly winds backing to the west introduced an element of downsloping. Compressional warming from this was not offset by any other temperature advection, and allowed for temperatures to hit exactly the average high for this time of year. The other aspect I missed on was max wind speed. Here, looking at surface analyses from yesterday compared to the forecast models, there was a larger distance between the center of high pressure and the departing coastal low, leading to a weaker than expected pressure gradient early. The fastest winds ended up being clocked from the southwest as a result, ahead of the approaching cold front.
Weather Prediction Surface forecast for 7AM Thursday
Synoptic Set Up The forecast period starts with a north-south elongated high pressure over much of the Eastern US, centered over the Ohio Valley. The coastal low that impacted the area Monday is still forecast to linger southeast of Nova Scotia. A decent pressure gradient will be in place at the beginning of the forecast period as a result (high pressure measuring ~1025 mb, low ~998 mb). An approaching low pressure center will travel northeast from the Midwest across the Great Lakes into Southwestern Quebec during the forecast period. The low will continue intensifying and will erode the northern part of the high pressure center. Precipitation associated with this low won’t reach NYC until Friday, though. The primary influence of this low for the forecast period will be in shifting winds from the northwest to the southwest.
Above the surface, at 850 mb winds are forecast to start off northerly, between 20-25 knots. Wind speeds ease as they continue backing from north to west, then pick up in intensity to 30 knots from the southwest. Dry air, though moistening, will prevail at the 850 mb level throughout the forecast period. At 500 mb, slight ridging takes place during the day, then increased vorticity starts to pivot through ahead of the primary shortwave axis associated with the maturing surface low over the Great Lakes. Finally, at 300 mb we’ll start in the entrance region of a jet streak, then followed by a period of calm before the exit region of another jet streak approaches from the west.
GFS 2-meter (surface temperatures) in contours, and 10-meter wind barbs, valid 1AM Thursday. This shows a decent environment for cold air advection with winds at almost perpendicular angles to the temperature contours, pointing from colder to warmer temperatures. However, wind speeds are modest so the strength of an CAA would not be strong.
By 1AM Friday, GFS 850 mb height, moisture, and winds show depict winds shifting to the southwest, but the air above the surface will still be quite dry.
High Temperatures Statistical models (GFS, NAM, NBM) are good agreement, within a degree or two of 50°F. EKDMOS at 12Z similarly showed a tight band around 50°F, though this widened a bit at 18Z. 50°F is just a touch below climatological norms. I’m not seeing too many surprises here. Moisture is lacking for clouds to form until late in the period after the sun goes down. As winds shift to the southwest later in the day, they will largely parallel local isotherms so there won’t be appreciable warm air advection to look at either. I think 50°F is a good bet here.
Low Temperatures Stiff winds from the northwest will offset relatively clear conditions in terms of radiational cooling. Cold air advection (CAA) is looking modest. While the wind direction is looking to cut at almost perpendicularly across temperature contours from cold to warmer temperatures, wind speeds aren’t going to be sustained at strong speeds for too long. I think 38°F is reasonable because statistical guidance is only a degree cooler or so, with EKDMOS showing this temperature at about the 50th percentile.
GFS MOS forecast
NAM MOS forecast
Max Sustained Winds 850 mb winds have two peaks and so do surface winds in EKDMOS: one early, then one late in the forecast period. I tend to concur the fastest winds will come early in the forecast period, since northwest winds are climatologically favored to produce fast high speeds. However, I also don’t see evidence to support mixing of strong winds aloft down to the surface. One wrinkle is if the pressure gradient ends up being tighter between the lows and the high pressure, as that would drive stronger than anticipated winds. 20 mph is above statistical guidance, but not that much higher.
NAM forecast sounding for KLGA valid 7PM Thursday. Distinct moistening of the mid and upper levels is evident with the dew points (green line) nearly overlapping the environmental temperature (red line). Lower levels are still markedly drier.
Total Precipitation This is the easiest part of the forecast as strong high pressure and dry air throughout most of the atmospheric column for most of the day makes it nearly impossible for precipitation to materialize.
Spells of rain will bookend what should otherwise be a pleasant week of mostly dry weather. Temperatures will trend slightly below normal for this time of year, however, we will avoid any dramatic swings in temperature. Record cold will not be on the table either. All in all, it should shape up to be a fairly typical mid-November week.
Rest of today – windy, mostly cloudy, with chances for scattered rain showers as a slow moving coastal low continues spinning off of the coast of New England. High temperatures should only hit the mid-40s with the cooling influence of clouds and persistently northeasterly flow. Chances for rain continue overnight with lows dropping into the upper-30s.
Weather Prediction Center surface forecast for 7PM Monday
Tuesday – rain chances should finally end as the coastal low affecting us finally pulls away to the northeast. Clouds should break up leading to a decent day with high temperatures in the low-50s. Overnight lows should be around 40°F.
Wednesday – partly sunny with highs around 50°F. Overnight lows in the mid-30s.
GFS 500 mb height, relative vorticity for 1PM Friday. We can see a distinct shortwave trough approaching from the west. Enhanced vorticity around the base of this trough should help touch of some precipitation at the surface as a cold front sweeps through.
Thursday – best day of the week with high pressure briefly building in. High temperatures again around 50°F, with overnight lows in the mid-40s.
Record setting cold is on the way mid-week. Overnight lows in the mid-20s and daytime highs hovering around freezing Wednesday will make this week feel more like January than mid-November. Luckily, this bitter cold snap will be short-lived, with temperatures rebounding back into the 50s by the end of the week.
Rest of today – temperatures will be falling through the 40s during the day. Precipitation should end as an Arctic front pushes through. Temperatures will continue dropping into the 30s throughout the evening and bottoming out in the mid-20s. Precipitation should end before it gets cold enough to produce snow. Winds will become stiff with the parent low strengthening and a tight pressure gradient forming between that and an incoming high pressure center.
Weather Prediction Center surface forecast for 7AM Wednesday
Wednesday – sunny with record low high temperatures in the low-30s as a frigid Arctic air mass takes hold. Overnight lows continue to be cold, in the upper-20s.
Thursday – temperatures start to rebound into the upper-40s as a warm front approaches and we enter the warm sector of the next storm. Return flow around the western edge of the high pressure exiting east will also assist in helping move some warmer air in. Overnight lows in the mid-30s.
GFS model 500 mb temperature, height and wind at 1AM Wednesday, note the closed 500 mb low and the strong troughing over much of the Northeastern US
By 7PM Friday, the 500 mb trough is forecast to have flattened out considerably, allowing for temperatures at this level and at the surface to rebound
Friday – the warm-up continues, with temperatures reaching back into seasonable levels in the low-50s. A moisture starved cold front passes through late bringing overnight lows back down to the low-30s
