Good news to report regarding Hurricane Joaquin – since yesterday, forecast models have arrived at a much clearer consensus regarding the track of Joaquin once it leaves the Bahamas – and the resulting forecast track takes it well east of the US East Coast.
This means we will luckily miss any severe impacts from a landfalling tropical cyclone. However, with Joaquin to the south and a ridge of high pressure to the north, continuous onshore northeasterly winds will still present moderate coastal flooding issues. Temperatures will likewise remain cool under the clouds and onshore flow, with rain expected to continue from today until Saturday. Lingering showers may persists on Sunday.
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.
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.
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.
This is going to be an uneventful week in terms of weather. High pressure dominates through out the period, leading to dry, sunny conditions every day, with the only variation being a warming trend after Tuesday.
Rest of today – gorgeous, fall-like day with high temperatures only topping out in the low-mid 70s. A breezy west wind will make it feel even more like autumn.
Tuesday – warmer, with high temperatures in the low-80s under sunny skies.
Wednesday – warmer still with high temperatures in the mid-80s.
Thursday – another picture perfect day with plenty of sun and high temperatures in the low-mid 80s.
Some much needed rain is falling today, with another round of rain coming this weekend. Friday and Saturday look to be the best days out of the stretch, while Sunday has the best chances for rain. The tradeoff for this wet weather will be noticeably less humid, cooler, and more seasonable conditions to start off next week.
Rest of today – we are currently in a dry pocket which should last through the late afternoon hours. The cold front that is initiating these showers and scattered thunderstorms will be slow to move through. A low pressure center that is riding along the frontal boundary is currently parked over us, and as this low continues to move off to the northeast, additional rain is expected develop and wrap around the backside of the low. With this low and the front lingering, we will likely get another round of widespread showers with some heavy downpours possible again later this evening and into the overnight hours. With the rain and cloud cover, highs will only reach the upper-70s before dropping back down.
Friday – once the low pressure and cold front have passed, conditions should begin to improve quickly. There’s a lingering chance for showers in the morning, but by the afternoon hours skies should be clearing with high temperatures around 80.
Saturday – another cold front and low pressure will follow on the heels of today’s system. The timing of precipitation with this system appears to be trending towards late Saturday evening, and primarily overnight into Sunday. This should allow for a mostly sunny day with temperatures again around 80.
Sunday – showers appear to be likely on Sunday, with an isolated thunderstorm possible as well. High temperatures will be in the upper-70s with the clouds and rain.
Monday – once the storm system passes on Sunday, high pressure building to our southwest will allow cool, dry air from Canada to flow into the area, resulting in temperatures again in the upper-70s, but with mostly clear skies.
Another steamy beginning to week is following on the heels of Labor Day. Today and Wednesday are both days when the temperature could top 90ºF. By Thursday, a strong cold front moves through, bringing the potential for much needed rain and cooling things off considerably for the end of the week.
Rest of today – sunny, hot and humid, high temperatures in the low-mid 90s in the city. Humidity remains just low enough to obviate the need for any excessive heat watches/warnings.
Wednesday – increasing clouds from west to east on Wednesday ahead of an approaching cold front. Temperatures remain warm ahead of the front, generally in the upper-80s with maybe a couple spots topping 90. There could be a few pop up showers and thunderstorms later in the afternoon, perhaps along a sea breeze front in Brooklyn/Queens.
Thursday – widespread showers and thunderstorms will be the order of the day, with cooler temperatures in the low-80s and cloudy conditions. Periods of showers and thunderstorms could persist for extended periods of time, bringing the potential for flash flooding in some locations. Rain ends from west to east gradually during the overnight hours.
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.
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.
We have a simply splendid weekend on tap. Temperatures will be on the upward trend through the end of this week and into the weekend. The warm trend will continue into the beginning of next week, along with a return of more humid, dog days of summer type weather. Keeping an eye on the tropics, a great deal of uncertainty surrounds the future of Tropical Storm Erika, which could effect the U.S. East Coast in the long term.
Rest of today – beautiful, sunny skies with high temperatures in the low-80s. High pressure to the west is firmly in control, delivering this pleasant, seasonable weather.
Friday – almost a carbon copy of today, high temperatures in the low-80s with even fewer clouds as the high pressure center will be parked right over us.
Saturday – as the high pressure from the end of the week moves offshore and weakens, a subtropical high pressure center begins to take to control. This setup favors a warmer, more humid regime. Winds will shift to the southwest and temperatures will begin to climb into the mid-upper 80s.
Sunday – a longer term trend of warm and humid weather, typical of late summer, will continue Sunday. Temperatures will again be in the upper-80s. This trend looks to continue well into next week.
Tropical Storm Erika
A tropical wave that moved offshore of West Africa late last week has tracked across the Atlantic, strengthening along the way to become the fifth named storm of the 2015 Atlantic Hurricane season. Tropical Storm Erika, like its predecessor Danny, is having trouble maintaining its strength due to the influence of dry air and hostile northwesterly wind shear. Due to this shear, Erika’s center of circulation is actually still somewhat exposed (see below), and displaced away from its area of heaviest thunderstorms, which is concentrated in the southeastern quadrant of the storm.
The long term prospects for the storm are highly uncertain due to a number of factors. Erika looks to be tracking over Puerto Rico and may interact with Hispaniola (bringing much needed rain), which would significantly weaken the already feeble storm. This could lead to it dissipating entirely. However, should the storm make it past this area of high wind shear and possible land interaction, it’ll end up in the very warm waters around the Bahamas. This would provide the fuel for it to intensify quickly into a hurricane which could then threaten Florida and the East Coast. Definitely worth keeping an eye on.
Satellite image of Erika, with exposed center of circulation circled in red
A slow moving cold front brings an unsettled start to the week. Ahead of this cold front, temperatures will rise along with humidity, leading to a late-summer feel. Once this frontal boundary passes, high pressure to the west will allow for a cooler, drier Canadian airmass to enter the region, leading to more seasonable temperatures along with sunny skies.
Rest of today – a mix of sun and clouds continues with a small chance of some rain, with temperatures topping out around average in the low-80s.
Monday – as a cold front approaches from the west, humidity and temperatures will rise along with a south wind. There is some small chance for thunderstorms, especially west of the Hudson. Otherwise, expect a mix of sun and clouds with temperatures in the mid-80s.
Tuesday – with the cold front lingering in our vicinity, a small chance for showers and thunderstorms continues, along with warm and humid temperatures in the mid-upper 80s.
Wednesday – the cold front finally pushes through Tuesday, and gives way to high pressure building in from the west on Wednesday. This will lead to comfortable temperatures in the low-80s with sunny skies.
Thursday – similar conditions to Wednesday, with sunny skies and a pleasant, comfortable high in the low-80s.
A Note on the Tropics
We’re about to enter the most active period of the Atlantic hurricane season, and things have definitely picked up in the tropics. A series of monsoonal tropical waves are moving off of the cost of West Africa, giving rise to the potential for a couple of Cape Verde type tropical cyclones. This conveyor belt of tropical waves has already spawned this season’s first hurricane, Danny, which peaked as a major hurricane with winds of 115mph (Category 3) at the end of last week. Danny has weakened considerably, but could still bring some much needed rain to Hispaniola and Puerto Rico in the next couple days. Meanwhile, another tropical wave following on Danny’s footsteps could become Tropical Storm Erika in the coming days. Neither of these storms poses any immediate threat to the United States for the time being.
A heatwave over the weekend breaks Tuesday, as we enter an extended period of unsettled weather for the mid-week period. Temperatures cool off somewhat into the mid-80s, slightly above average for this time of year. Each day, except Tuesday perhaps will carry some small but non-zero chance of rain.
Rest of today – the possibility exists for some isolated thunderstorms to form over portions of the region this afternoon. The setup would be similar to yesterday when the temperature differential resulting from a sea breeze served as the trigger for some slow-moving storms. Plenty of instability from the heat and humidity and very little convective inhibition will mean that storms could form rapidly. However, the exact location of where these storms form is difficult to pinpoint. Areas that experience storms could expect heavy rain, otherwise expect mostly sunny skies with high temperatures that could touch record levels in the mid-90s.
High resolution rapid refresh model simulated radar for 2PM EDT today
Tuesday – a bit cooler with temperatures in the upper-80s and sunny skies to start, clouds increasing towards the evening.
Wednesday – high temperatures will cool off further into the mid-80s under cloud cover, and there will be a chance for rain throughout the day. This precipitation is associated with a slow-moving cold front approaching from the west.
Thursday – a similar day to Wednesday, perhaps with a bit more sun, but highs again in the mid-80s and a chance of rain through the day
The pleasant weather we’ve had the past two days gives way to a hotter, more humid feel appropriate for August. High pressure that has been giving us this wonderful weather will be steadily moving east. Temperatures will warm and the air will moisten as winds shift to the south and southwest. We’ll likely see temperatures at or above 90ºF for the weekend.
Rest of today – clear skies with comfortable high temperatures in the low 80s.
Friday – warmer, with high temperatures rising into the mid-80s. Humidity will begin to increase.
Saturday – probably will be the warmest day of the weekend with highs at or slightly above 90ºF. Afternoon thunderstorms are possible especially inland, though unlikely at the coast.
Sunday – just a tad less hot as a weak cold front pushes through, but still sunny with high temperatures in the upper-80s.
