Category Archives: Drought

NYC Weekend Weather – Sept 25, 2015

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Missed a couple updates the last week or so. The weather has been fairly uneventful during this stretch, with the second week of September featuring much above temperatures, while this past week has been more seasonable with respect to temperatures. This weekend, the pleasant, fall-like weather continues, with Saturday being the better half of the weekend.

Rest of today – high clouds have decreased in coverage somewhat since earlier this morning, but with an area of low pressure off the Southeastern US edging northward, cloud coverage may increase again later today. There’s also an onshore flow pattern with wind coming from the northeast, which will keep high temperatures suppressed in the low-70s.

Saturday – Canadian high pressure builds north of us, keeping the area of disturbed weather that’s moving northward from the Southeast at bay. This should result in a mostly sunny day. However, with the high pressure center to the north, onshore winds will continue from the northeast, leading to high temperatures again only in the low-70s.

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Sunday – the high pressure above will move southeast offshore of New England by the end of the day Sunday. With the high out of the way, the low pressure to its south will be able to develop again. This should yield a mostly cloudy day with the possibility for rain later in the evening hours. High temperatures remain on the cool side in the low-70s.

Monday – the chance for rain increases Monday with the high pressure completely out of the picture and low pressure moving in. This rain is much needed as a moderate drought persists in the NYC region (in particular Long Island). High temperatures will be warmer with winds from the southwest, temperatures may approach 80.gfs_namer_066_1000_850_thick

Regional Drought Worsens

The tradeoff for the long stretch of dry and pleasant weather is that moderate drought conditions have returned to areas which had been close to being drought-free last month. Moderate drought has redeveloped over much of the NYC metro area, while a persistent drought has continued to affect eastern Long Island. In fact, since August, the percentage of New York State affected by moderate drought has more than doubled.

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NYC Weather Update – Aug 31, 2015

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A heat wave is on for the end of August, and will persist into the beginning of September. A hot, humid tropical airmass will be firmly in control through out the early and mid-week period before we get some heat relief late in the week. The hot temperatures and a lack of widespread precipitation may allow drought to redevelop in some parts of the region, and worsen over Long Island.

Rest of today – possibly the hottest day of the week, with temperatures in the low-mid 90s inland despite some cloud cover and uncomfortable humidity levels.

USA_East

Tuesday – a weak backdoor cold front pushes through overnight, although no precipitation is anticipated due to insufficient instability. Tomorrow should see high temperatures in the lower 90s again under sunnier skies.

Wednesday – the heat wave continues with temperatures yet again expected to top out in the low-mid 90s with sunny skies. There could be a few isolated pop-up showers/thunderstorms late in the day with very limited coverage.

Thursday – expected to be the last day of the heat wave, sunny with high temperatures at or above 90.

NYC Weather Update

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The weather story for the first part of this week will be a prolonged heavy rain event occurring Tuesday, delivering parts of the region some much needed precipitation. Temperatures will remain slightly below normal through Thursday, first because of the rain and clouds and then due to the influence of high pressure to our west.

Rest of today – NYC remains under mostly sunny skies, however, cloud cover is building to our west, so we could end up with more clouds later this afternoon. It will be a noticeably more humid day, although temperatures will still only top out in the low-80s.

Tuesday – rain should begin falling in the early overnight hours, and looks to persist through the morning and into the early afternoon hours. The heaviest rain seems likely to fall during the morning hours. Thunderstorms cannot be ruled out, and while the atmospheric conditions will not be very favorable (timing of the strongest lift will occur early in the day before any substantial daytime heating, which will be diminished due to cloud cover anyway), a few strong storms could still pop up in the morning. Some areas could see some isolated flash flooding if storm cells end up training over the same spots. Under the cloud cover and rain, high temperatures should be limited again to the low-80s.

North American Model High Resolution simulated radar for 11AM EDT Tuesday
North American Model High Resolution simulated radar for 11AM EDT Tuesday

Wednesday – rain will have cleared out after the passage of the cold front responsible for Tuesday’s storms. Behind this cold front, high pressure will set up over the Ohio Valley, bringing in cool, dry air. Temperatures will be quite comfortable in the low-mid 80s with low humidity.

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Thursday – the pattern of cool, dry weather continues with another day of sunny skies and high temperatures slightly below normal in the low-80s.

Drought Relief

A slight/moderate drought continues to cling to areas of Long Island and costal Connecticut, as you can see from the map below. It does appear that this upcoming Tuesday storm will bring some much needed rain to these particular areas. As you’ll also note from the map of forecast precipitation totals for Tuesday, some of the highest totals are expected precisely in the areas that need them the most.

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Weather Prediction Center's Quantitative Precipitation Forecast for total precipitation between 8AM EDT Tuesday and 8AM EDT Wednesday
Weather Prediction Center’s Quantitative Precipitation Forecast for total precipitation between 8AM EDT Tuesday and 8AM EDT Wednesday

NYC Weekend Weather – Jul 23, 2015

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The end of this week and weekend will be characterized by comfortable conditions and seasonably warm temperatures. A cold front from Canada will be approaching from the west by Sunday, however, this frontal boundary looks to weaken as it nears the area. There should be a small chance for showers and thunderstorms, but it is likely most areas stay dry through the weekend.

Rest of today – high pressure over the Ohio Valley will yield sunny skies, with a high in the mid-80s. Dry air moving from the west will make for a pleasant feel today.

Friday – high pressure remains in control tomorrow, providing for conditions almost identical to today, with highs again in the mid-80s under sunny skies with low humidity.

Saturday – although the high pressure center will weaken somewhat as it moves east on Saturday, it will still dominate our sensible weather, leading to yet another day of basically the same weather conditions with highs in the mid-80s and plenty of sun.

Sunday – with the high continuing to weaken and move to the southeast, we get a chance for some afternoon showers and thunderstorms associated with a frontal boundary originating in Canada moving into the region. Rain chances aren’t all that high, though, so it’s likely most areas stay dry. Highs again in the mid-80s with increasing cloud cover.

Global Forecast System model output for Sunday at 11AM EDT
Global Forecast System model output for Sunday at 11AM EDT

Drought Update

Drought conditions over New York state have drastically abated since the beginning of the month, especially in upstate regions. However, moderate drought persists over parts of Long Island.

Drought index for New York State, areas in yellow indicate slight drought, while areas shaded in tan indicate moderate drought.
Drought index for New York State, areas in yellow indicate slight drought, while areas shaded in tan indicate moderate drought.

NYC Independence Day Weather – Jul 3, 2015

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Pleasant weather today will give way to more unsettled weather for Independence Day. Showers are likely during the day Saturday, however, it appears that rain should move out before the fireworks start. Sunday sees a return to sunny weather, with the beginning of next week starting off dry.

Rest of today – sunny skies should yield comfortable high temperatures in the low-mid 80s.

Saturday (Independence Day) – an area of low pressure is forecast to pass to the south of Long Island Saturday. Rain showers are possible during the day along a nearly stationary frontal along this low pressure center. With the low pressure to our south, we will be experiencing southeasterly, easterly, then northeasterly winds associated with the counterclockwise rotation around the low. These winds and mostly cloudy skies will serve to suppress high temperatures to well below normal in the mid-70s range.

Now, the all-important question: will it rain during the fireworks displays? As of now, it appears that the bulk of any rain is expected to have moved offshore or east of the area by 8PM Saturday, which should allow for dry conditions during fireworks displays.

 

North American Model high resolution simulated radar for 8PM EDT Saturday
North American Model high resolution simulated radar for 8PM EDT Saturday

Sunday – conditions improve rapidly during the overnight hours Saturday into Sunday. Sunday will feature sunny skies, and highs in the low-80s.

Monday – an increase in cloud cover will herald the next week, with high temperatures remaining in the low-80s.

 

Drought Update

Drought conditions continue to abate in the region with multiple rounds of significant precipitation events. However, moderate drought persists in Eastern Long Island, as depicted in the beige shaded areas below.

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NYC Weekend Weather | Jun 25, 2015

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The first half of this first full week of the summer felt very much like mid-summer, with hot, humid conditions and even some severe thunderstorms. The second half of this week, along with the weekend will feel a lot more like late spring, with Saturday afternoon into Sunday morning shaping up to be a washout.

Rest of today – pleasant, sunny skies, with a wind from the northwest, will yield comfortable high temperatures in the mid-80s.

Friday – an area of low pressure will be tracking eastward from the Midwest along a nearly stationary frontal boundary that will be positioned over southern New Jersey. The timing of this wave of low pressure will be overnight Thursday into Friday morning. Rain should end by noon Friday. With mostly cloudy skies, high temperatures will only top out in the mid-70s.

North American Model high resolution simulated radar image for Friday at 8AM EDT
North American Model high resolution simulated radar image for Friday at 8AM EDT

Saturday – the respite from the rain will be short-lived. Saturday morning into the early afternoon should remain rain-free, though temperatures will again be suppressed in the low-mid 70s. Another, more potent area of low pressure will make its approach from the west during the day Saturday. The precipitation shield associated with this low should begin to fill in over the area beginning in the mid-afternoon hours. Periods of showers will continue falling, with moderate to heavy rain at times, throughout the remainder of the day and overnight Saturday.

North American Model high resolution simulated radar for Saturday at 2PM EDT
North American Model high resolution simulated radar for Saturday at 2PM EDT

Sunday – rain begins to taper off on Sunday from south to north as the center of the low pressure responsible for this storm moves to our northeast. Rain should end in the early afternoon hours. Mostly cloudy skies are expected with temperatures in the mid-70s. Rain from last week has put a dent in drought conditions across New York state, but areas of Central upstate New York and eastern Long Island could still use this rain. The downside is that it will put a damper on many outdoor plans for the first full weekend of the summer, and the first weekend after school ends here.

Monday – conditions improve on Monday as the low pressure continues to pull away. High temperatures should remain in the mid-70s with cloud cover decreasingly steadily.

 

NYC Weekend Weather – Jun 19, 2015

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In contrast to last weekend, where Sunday was the better half, the reverse will be true this weekend. Remnants of Tropical Depression Bill will be moving over us on Sunday, bringing the potential for extended periods of showers and heavy rain. It is hoped that this much needed rain will put a dent in the persistent moderate drought conditions in the region.

Rest of today – there is a small chance for thunderstorms up until around lunchtime today, after which skies should gradually clear. High temperatures are expected to top out in the upper-80s to near 90.

Saturday – high pressure will be shifting to the east, bringing in an onshore flow, keeping temperatures cooler in the upper-70s under partly sunny skies. Chances for rain will be increasing steadily through the evening such that by the overnight hours, periods of steady rain should be the norm.

Sunday – As referenced above, remnants of Tropical Depression Bill, still carrying tropical moisture, will be moving over the region. There is still some uncertainty as to whether the areas of heaviest rain will move further south and over the ocean, however, at this point it seems likely that Sunday will feature periods of steady rain, heavy at times. Rainfall probability and rainfall totals will drop precipitously from south to north, since the storm center is expected to track to our south. We could pick up as much as 1″-1.5″ of rain over Long Island, which would be a blessing since this area is still in the grip of moderate drought conditions. With clouds and rain, high temperatures should top out around 80.

Quantitative Precipitation Forecast for Sunday
Quantitative Precipitation Forecast for Sunday
North American Model high resolution output for Sunday at 11AM EDT
North American Model high resolution output for Sunday at 11AM EDT 
Drought coverage in New York as of this week
Drought coverage in New York as of this week

Monday – conditions improve following the passage of the storm on Sunday, with high temperatures rebounding into the mid-upper 80s under mostly sunny skies.

NYC Weekend Weather – Jun 4, 2015

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We have struggled to reach normal temperatures this week, with plenty of rain and Wednesday as the only sunny break. We end this week with more cool, damp weather, before transitioning to warmer, drier conditions this weekend. Portions of the area received anywhere between 2-4″ of rain between Sunday night and Tuesday night, which will help improve drought conditions, however, these rainfall totals also led to flash flooding across large portions of the area.

Rest of today – cloudy, with a small chance for isolated light showers, cool with temperatures topping out only in the low-mid 60s, about 10ºF below normal for this time of year.

Atmospheric setup favoring the cool, cloudy, damp weather
Atmospheric setup favoring the cool, cloudy, damp weather

Friday – more clouds and cool weather, with this easterly onshore flow regime sticking around for one more day. High temperatures will again be only in the mid-60s, much below normal. There is a slightly higher chance Friday for scattered showers, but nothing like the soaking we got earlier this week.

Saturday – some improvement in conditions will take place Saturday as high pressure starts building from the west. Partly sunny skies may give way to more sun, with high temperatures warmer near 80.

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Sunday – high pressure moves to our east, allowing us to enjoy another pleasant, dry day, with high temperatures in the mid-70s.

Monday – a frontal system approaches the area. Ahead of the front, warmer air will flow in from the southwest, giving us temperatures at or above normal near 80ºF. As the front nears, thunderstorms and showers are possible across the region.

 

Arctic Jet Stream Slowing Leading to Increased Incidence and Duration of Extreme Weather? 

The massive quantities of snow that fell over the Northeast this past winter, the flooding rains over Texas last month, the enduring drought over California, and the asphalt-melting heatwave in India have all raised the question of what is causing this apparently increased incidence of long-duration extreme weather events. One possible explanation offered by researchers at Rutgers University is that the polar jet stream circling the Arctic has been slowing.

Jet streams are generated by two factors: the rotational energy of the Earth spinning on its axis, and the pressure gradient between two airmasses of varying temperatures. In the case of the polar jet circling the Arctic, rapid warming of the Arctic over the last couple decades has led to a decreased thermal and pressure gradient between air over the Arctic and air directly to the south. Researchers posit that this effect has led to a slowing of the polar jet stream. Since the jet stream is responsible for moving large (synoptic) scale weather patterns, any affect on its speed and orientation can have dramatic impacts for widespread regions of the world. In this case, the slowing polar jet stream is theorized as the mechanism behind the prolonged effects of the weather events mentioned above.

NYC Weather Update – May 26, 2015

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It certainly does feel as though Memorial Day 2015 has been the unofficial start of summer, given the warm and humid temperatures we’ve had from Sunday onwards. The warm, late-June like temperature trend continues through mid-week, with some chance for thunderstorms. Rain in any form would be most welcome, given that the region has been placed in a region of moderate drought as of this week.

Rest of today – the Bermuda high, more typical of mid-summer, brings us very warm and humid high temperatures in the mid-upper 80s, more than 15ºF above average for this time of year. If you like the heat, go out and enjoy it because we might see showers and thunderstorms both Wednesday and Thursday afternoons.

Wednesday – a weak cold front approaches from the west, bringing with it a chance for showers and thunderstorms. The critical question for NYC will be how long organized storms can stay together as they enter into influence of cooler, maritime air nearer to the coast. Temperatures will remain warm in the low-mid 80s with clouds and some breaks of sun. As is generally the case in these setups, the more sun we can get in the afternoon ahead of the frontal bou

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North American Model high resolution simulated radar image for 8PM EST Wednesday

Thursday – we get another shot at thunderstorms Thursday afternoon and evening, with highs likely topping out around 80 under mostly cloudy skies.

 

Moderate Drought for the Region Forecast to Persist

We’ve had an remarkable run of sunny, rain-free days, and above average temperatures for much of May (and indeed even going back a couple of months), and while that’s translated to pleasant weather for outdoor activities, it also has meant that we’ve entered into a stretch of moderate drought. We had a stretch of no rain for 23 consecutive days, earlier this month, which definitely didn’t help things. According to the USDA Drought Monitor, Central Park recorded 7.12″ of rain from March 1st through May 19th, which is only about 63% of average for this time of year.

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While we are only in the lowest tier of drought and were just added to this category this week, these drought conditions bear watching. We hope to get some rain out of this week, and it looks like more storms are on the way this weekend, however, the drought forecast for our region looks to have the drought persist through this summer.

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NYC Weekend Weather & West Coast Storm – Dec 2, 2014

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It’s been a up and down week for weather in NYC, with Monday starting out in the mid-60s, then a colder mid-week that featured some mixed precipitation and rain. The end of this week will feature rain and slightly warmer temperatures by Saturday, then a return to colder conditions Sunday into next week. I’m also going to point out some of the spectacular weather brought on by a huge Pacific storm that hit California this week.

Thursday – the remainder of today will be pleasant and sunny, though cold with high temps only in the low 40s.

Friday – clouds will begin to build overnight tonight ahead of the a storm system moving in from the Southern Plains to the Ohio Valley. There is a small chance for scattered showers, otherwise expecting a cloudy day with highs in the mid-40s.

Saturday – rain should overspread the area by Friday night into Saturday. This storm system will be drawing on energy and moisture from the Pacific storm that slammed California earlier this week (discussed below). Combined with influx of Gulf moisture, this setup favors a moderate to at times heavy rain event for Saturday. Temperatures will rise steadily ahead of this storm system as it pushes warm air up. High temperatures Saturday should reach into the mid-50s despite rain and clouds.

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GFS model output for overnight Friday into Saturday

Sunday – rain should end overnight Saturday, and high pressure from Canada should quickly build in behind this storm system. The positioning of this high pressure, along with the exiting low, will make for a tight pressure gradient, which should allow for stiff northwest winds perhaps in the 15-25mph range. Temperatures will drop back into the low 40s with the arrival the colder Canadian air.

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GFS model output for Sunday night

Monday – the storm system from Saturday will move offshore, but it appears from model runs that there’s some chance the storm lingers. As the high pressure from Sunday moves off to the northeast, the clockwise flow behind it may draw this offshore area of low pressure back into the area. This could lead to some rain on Monday. It’ll be a mostly cloudy day otherwise with highs in the low 40s.

Pacific Storm Slams California

Earlier this week, California got slammed by a very strong Pacific low. This storm brought on furious rains that dropped 1″+ in many areas of Northern California, with totals as high as 3-4″ in spots near the Coast Range and Sierra, as well as further south in the mountains east of San Diego. These totals represent more rainfall than had fallen in many of these areas all of last year.

You can see from the map below which overlays drought conditions (the deeper the red, the more extreme the drought, with the darkest red representing extreme/record-breaking drought) with rainfall totals from yesterday. You’ll see that much of the heaviest rain did fall over regions worst affected by drought. Sadly, though this is a case of too much of a good thing, as much of this desperately needed rainfall occurred so quickly, it will simply runoff back into the ocean.

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Map of California with drought condition layer (reds/oranges), and rainfall totals from yesterday