All posts by Lei Zhao

NYC Weather Update – Dec 7, 2020

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A week of contrasts is in store for us with colder than average temps in the low-40s to start things off. However, a warming trend will take hold as a more zonal flow evolves at the upper levels, moderating heights and temperatures. This will result in milder conditions later on in the low-50s.High pressure and dry northerly flow should keep things rain-free until closer to the weekend.

Rest of today – below normal high temperatures around 40ºF with increasing clouds as a low pressure center passes well off to our southeast over the Atlantic. The presence of this storm offshore will result in persistent northerly winds, though less potent than over the weekend. Overnight lows in the low-30s.

Weather Prediction Center surface forecast for 7PM Monday. Note the presence of a low pressure center east of North Carolina.

Tuesday – high pressure briefly builds in and provides a mostly sunny day but with temperatures still only peaking around 40ºF. Overnight lows again in the low-30s.

Wednesday – high temperature start to rebound towards normal in the mid-40s with partly sunny skies as a storm passes well to our north, and we end up in the storm’s warm sector. Overnight lows drop into the upper-30s.

GFS model 500 mb temperature, height and winds forecast for 1PM Thursday. Flow at this level is forecast to become more zonal (flatter) than earlier this week.

Thursday – temperatures jump into the low-50s with sunny skies as high pressure briefly moves in again and upper level flow starts to flatten out resulting in the colder air mass in place to start the week getting pushed north. Overnight lows in upper-30s.

NYC Weekend Weather – Dec 4, 2020

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A strong nor’easter/coastal low will impact NYC tonight into Saturday. Conditions will deteriorate with the worst weather overnight into tomorrow morning. Gusty winds, soaking rains will accompany this storm. Temperatures will also drop as the storm moves off northeast and winds turn to the north and northwest, however, cold air wrapping around the low will not arrive in time to set the stage for accumulating snow here. Storm clears out by later Saturday. Afterwards, calm, seasonably cool temperatures (low-40s) are in store for next week.

Rest of today – temperatures topping out in the upper-40s with warm air advection/warm front moving up ahead of the main storm. Cloudy, with chances for rain increasing through the day, mostly on the lighter side. Overnight lows largely holding steady in the mid-40s again due to the influence of the incoming warm front. Rain expected to increase in intensity overnight going into Saturday morning.

  • ECMWF hi-res model surface precipitation/precipitation type valid 7AM Saturday
  • ECMWF hi-res model surface precipitation/precipitation type valid 1PM Saturday
  • GFS model surface precipitation/precipitation type valid 7AM Saturday
  • GFS model surface precipitation/precipitation type valid 1PM Saturday

Saturday – models are in pretty good agreement (see above images from GFS and ECMWF models depicting evolution of this storm during the day Saturday) that this coastal storm will evolve quickly and intensify as it tracks offshore southeast of the region. This will result in periods of rain throughout the first half of Saturday, along with increasingly strong winds as the pressure gradient tightens around the deepening low. As the low tracks northeast, winds will be turning from the south to the north and northwest. This will bring in much cooler air, although not cold enough to support accumulating snow at the coast. As a result, temperatures will be dropping during the day Saturday into the low-40s. Precipitation should end rather quickly in the afternoon. Overnight lows will be in the low-30s wit winds easing.

Weather Prediction Center’s forecast storm track based on recent ensemble model runs.

Sunday – sunny with high temperatures in the low-40s. Overnight lows around 30ºF.

Monday – similar day to Sunday with sunny weather and high temperatures in the low-40s. Overnight lows again around 30ºF.

NYC Weekend Weather – Nov 20, 2020

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We’ll see warmer than average temperatures around 60ºF to start the weekend before a cool off into the 50s Sunday. Temperatures rise again Monday into the upper-50s with a warm front approaching, then cold front bringing a chance of rain. Looking ahead at Thanksgiving temperatures seem like they should be mild we may see some rain in NYC.

Rest of today – sunny with highs generally in the upper-50s to near 60ºF. High pressure south of the region will lead to southwesterly flow that will bring us these mild temperatures. Overnight lows in the upper-50s.

Saturday – a cold front is forecast to move through during the day, however, this front should be deprived of any significant moisture. Temperatures should remain mild in the upper-50s to around 60ºF once again. It won’t be until the overnight hours when temperatures start to drop in response to the cold front passage, with winds turning towards the north and lows falling into the low-40s.

Weather Prediction Center surface forecast for 7AM Saturday, showing a cold front approaching from the northwest.

Sunday – mostly cloudy with high temperatures cooling off to around 50ºF. A warm front approaching from the southwest should stabilize temperatures and prevent much of a change overnight with lows barely budging in the upper-40s. The warm front, then a cold front following on its heels should bring us a round of showers.

Monday – rain diminishing early on. High temperatures in the upper-50s occurring early in the day prior to the cold front passage. Temperatures dropping steadily during the day after this into the 40s. Overnight lows in the upper-30s.

Looking ahead at Thanksgiving, there could be some rain coming our way though temperatures appear like they should be on the mild side.

GFS model 500 mb vorticity and height forecast for 7AM Thursday. A closed upper low over the Ohio valley is evident with lots of accompanying vorticity. Should this scenario actualize, we would expect to see some showers in our area during the day Thursday.

NYC Weather Update – Nov 16, 2020

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What a big contrast in sensible weather this week vs. last! We were looking at record-breaking warmth in the upper-70s this time last week. Now, in the wake of a strong cold front and severe storms yesterday, temperatures cool off into the low-50s to start the week. A reinforcing cold front and high pressure brings much below normal highs only in the low-40s mid-week. A round of quick snow showers is possible going into Tuesday morning!

Rest of today – seasonably cool with westerly winds starting to die down. Sunny with high temperatures around 50ºF. Overnight lows in the upper-40s.

Weather Prediction Center surface forecast for 7AM Tuesday

Tuesday – clouds increasing as a cold front moves in from the northwest. High temperatures steady in the upper-40s. Chance of rain then rain and snow overnight. Overnight lows below average in the low-30s.

Wednesday – due to a cold start, and high pressure to the southwest, northwesterly winds will keep things cold on Wednesday with highs only around 40ºF despite sunny skies. Overnight lows drop into the low-30s.

Thursday – temperatures increase to the upper-40s with sunny skies. Overnight lows warming into the low-40s.

Hurricane Iota – A Major Disaster for Central America

A catastrophic disaster could be unfolding for Nicaragua and Honduras, in the same regions that were pummeled by Hurricane Eta barely two weeks ago. Hurricane Iota appears to be on its way to becoming a rare November Category 5 storm, and is looking very impressive on satellite images this morning. The torrential rain this storm brings could result in landslides, and inland flooding, exacerbated by soil that’s still quite damp from Eta’s onslaught. With recovery efforts ongoing, and people still without permanent shelter, Iota could be a major, life-threatening storm for this area.

GFS model 850 mb relative humidity and winds at 1AM Thursday, depicting some decently fast winds and ample moisture accompanying the cold front.

NYC Weekend Weather – Nov 13, 2020

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The record breaking warmth of last weekend and this past week will feel a world away this weekend with temperatures dropping to seasonable levels mostly in the 50s. Rain Friday will keep a damper on temperatures. Otherwise sunny conditions will be punctuated by a passing cold front Sunday bringing another round of rain. Temperatures will be mild ahead of the front around 60ºF before falling back into the low-50s. Colder air is in store next week with temperatures in the 40s.

Rest of today – cloudy with light rain possible as a wave of low pressure moves along a frontal boundary offshore. Highs in the low-50s. Overnight lows in the low-40s with skies clearing as high pressure builds in.

Saturday – with high pressure in control, expect sunny skies and seasonable temperatures in the low-50s. Overnight lows again in the low-40s.

Weather Prediction Center surface forecast for 7AM Sunday, showing a robust storm over the Great Lakes that will bring a cold front through our region later Sunday.

Sunday – a vigorous frontal system moves in from the west bringing rain chances later in the day and into the overnight hours. Southerly flow ahead of the front will bring temperatures up to around 60ºF. Overnight lows in the mid-40s with rain clearing out.

Climate Prediction Center 6-10 day temperature outlook for November 18-22, showing a decent chance for below average temperatures over the Northeast.

Monday – mostly sunny with high temperatures in the low-50s. Overnight lows around 40ºF.

NYC Weather Update – Nov 9, 2020

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The week starts with possible record breaking warmth carrying over from the weekend. Record high temperatures in the mid-upper 70s were set at several locations in the region yesterday. More records could fall today with highs in the mid-70s again. A general cooling trend takes place this week with highs eventually dropping back to seasonable levels in the upper-50s. A cold front mid-week with good moisture will bring a drenching rain Wednesday into Thursday.

Rest of today – very warm with possibly record breaking temperatures in the mid-70s once again under sunny skies. Overnight lows in the upper-50s with patchy fog possible.

Weather Prediction Center surface forecast for 7AM Tuesday

Tuesday – temperatures cool off a bit but still quite warm in the upper-60s to near 70ºF with more clouds. Overnight lows quite mild in the low-60s.

Wednesday (Veteran’s Day) – increasing clouds but still warm with high temperatures approaching 70ºF. A vigorous cold front will be moving in from the west. Rain chances increase through the afternoon. Most of the rain should occur overnight with good moisture content accompanying this front. Overnight lows in only dropping into the mid-60s with warm, southerly flow ahead of the frontal passage.

GFS model 850 mb relative humidity and winds at 1AM Thursday, depicting some decently fast winds and ample moisture accompanying the cold front.

Thursday – high temperatures occur early in the day prior to the passage of the cold front. Rain should subside as soon as the front passes. Behind the front, winds turn to the west and bring in a cooler, drier air mass. Temperatures should drop through the day with overnight lows bottoming out around 50ºF.

NYC Weekend Weather – Nov 6, 2020

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The warm weather we’ve seen this week carries right into the weekend with highs in the upper-60s to 70ºF, which is about 10ºF+ above average for this time of year. Slow moving high pressure dominates our sensible weather this weekend and into next week. Temperatures 8-10ºF above normal are forecast into mid-week next week. No significant rain chances either with this high pressure locked in through the weekend.

Rest of today – early low clouds and fog have been dissipating. Mostly sunny skies expected with high temperatures responding, climbing into the upper-60s and possibly topping 70ºF. Overnight lows drop back to the low-50s with a chance of fog developing.

Weather Prediction Center surface forecast for 7AM Sunday, showing high pressure southwest of NYC. This will be responsible for bringing us some spectacular weather this weekend.

Saturday – excellent weather continues with temperatures once again warming into the upper-60s and low-70s with plenty of sun. Overnight lows again in the low-50s.

Sunday – basically a repeat of Saturday, more sun, more warm temperatures in the upper-60s and low-70s. Overnight lows likewise low-50s.

Weather Prediction Center surface forecast for 8AM Sunday, showing high pressure anchored over the Northeast.

Monday – mostly sunny with high temperatures in the mid to upper-60s. Overnight lows in the mid-50s.

NYC Weather Update – Nov 2, 2020

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A cold, windy start to the week will give way to a marked warming trend. Today and tomorrow, strong winds are likely, and the west-northwest direction of these winds will promote below normal temperatures in the mid-40s and low-50s. Beginning mid-week, warm, southwesterly return flow developing around a couple high pressure centers will induce temperatures to rise into the 60s, closing in possibly on 70ºF by this weekend. This 10-15ºF above normal warmth looks set to continue into the weekend and possibly early next week.

Rest of today – mostly cloudy with clouds diminishing towards the evening. Highs much colder than normal in the mid-40s with cold air advection still influencing our sensible weather due to strong west-northwesterly winds sustained at 25-30 mph gusting to possibly 40-50 mph early. This is all due to the tight pressure gradient between a deepening low tracking over the Canadian Maritimes and a high pressure center further south. Overnight lows in the upper-30s.

Weather Prediction Center surface forecast for 8AM Wednesday

Tuesday – a secondary cold front pushes through early, possibly touching off a few showers in the morning. Winds still breezy, but not as strong as today. Mostly sunny skies with highs around 50ºF. Overnight lows around 40ºF.

Wednesday – sunny skies with southwesterly winds developing as high pressure builds northeast of us. This will allow for a much warmer day with highs around normal, near 60ºF. Overnight lows in the upper-40s.

Thursday – high temperatures continue trending up into the mid-60s with southerly winds and plenty of sun. Overnight lows in the low-50s. The warming trend continues into the weekend where we could see mid to upper-60s.

  • GFS model 850 mb temperature anomalies for 1PM Saturday. Very warm air will be in place over the region.
  • Climate Prediction Center’s 6-10 outlook for temperature trends suggests a high probability warmer than average temperatures continue into early next week.

NYC Weekend Weather – Oct 16, 2020

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A slow-moving cold front will bring rain to start the weekend from today into Saturday morning as several waves of low pressure move along this frontal boundary. Much colder air sweeps in behind this cold front with highs around 60ºF Saturday as high pressure builds with skies clearing. Overnight lows in outlying suburbs may be close to freezing, with frost developing. High pressure remains in place into early next week, maintaining dry weather. With the position of the high moving to the northeast, some warmer southerly return flow should help temperatures rebound into the mid-60s.

Rest of today – cloudy, with periods of rain, moderate at times. High temperatures peaking early in the day in the low-60s, dropping through the day. Overnight lows cooling off into the mid-40s as rain continues until perhaps 1-2am.

GOES geocolor visible satellite imagery of the Northeast this morning. Extensive cloudiness and some vertical development is apparent along a cold front that will impact the region Friday into Saturday.

Saturday – rain ending early. Gradual clearing with high temperatures cooler, around 60ºF. Overnight lows again on the cool side, in the mid-40s under mostly clear skies.

Sunday – high temperatures rebound a little into the mid-60s under mostly sunny skies with warmer southerly return flow developing as high pressure moves to the northeast. Overnight lows likewise warming into the mid-50s.

Weather Prediction Center surface forecast for 8AM Sunday, showing high pressure anchored over the Northeast.

Monday – partly sunny with high temperatures in the mid to upper-60s. Overnight lows in the mid-50s.

NYC Weather Update – Oct 13, 2020

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Rainy, cloudy conditions early today start giving way to high pressure as the low pressure offshore, remnant moisture from remnants of Delta, continues moving off to the east. High pressure takes hold mid-week with above-normal temperatures rising into the low-70s. Additional rain chances come towards the end of the week with another cold front forecast to pass Friday, leading to cooler low-60s over the weekend.

Rest of today – rain ending this morning with clouds sticking around and high temperatures in the mid-60s. Clouds diminish towards the overnight hours. Overnight lows in the low-50s with skies clearing.

Weather Prediction Center surface forecast for 8AM Wednesday

Wednesday – high pressure in place with warmer temperatures around 70ºF under sunny skies. Overnight lows in the mid-50s.

Thursday – similar day to Wednesday, high temperatures a touch warmer in the low-70s, with sunny skies. Overnight lows in the upper-50s with increasing clouds.

GFS model 2-meter above ground temperature anomalies for 8AM Friday

Friday – rain moves in especially later in the day and overnight. High temperatures still quite mild in the upper-60s with warm southerly flow ahead of the frontal passage. Overnight lows cool to around 50ºF following the frontal passage bringing rain.