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.
Unsettled weather will be a trend for the end of this week and into the weekend as a cold front pushes through the region. Friday is shaping up to be the worst day with heavy rain with a risk for flash flooding. Conditions improve somewhat Saturday and Sunday, although a chance for showers and thunderstorms cannot be ruled out either day.
Rest of today – slight chance of showers or thunderstorms persists through this afternoon, though the best chances remain west of the Hudson, as was the case yesterday. We’ve hit a humid highin the mid-80s with a mix of sun and clouds above.
Friday – a cold front will be pushing through during the course of the day Friday. As the frontal boundary approaches overnight and into the early morning hours Friday, a slow moving band of heavy rain is expected to form and track from north to south across the area. It appears likely that the heaviest rain will fall in a narrow band during the early morning hours, and that things may already be drying out by the AM rush. High temperatures will be cooler than average with the cloud cover and rain, near 80.
Satellite image of the storm that will be bringing us some heavy rain FridayHigh resolution rapid refresh simulated radar for 3AM EDT Friday
A chance for showers and thunderstorms continues through Friday. By the end of the day, some areas could pick up between 1-2″ of rain, raising the risk of some flash flooding.
Saturday – although high pressure will be building once the cold front passes on Friday, a chance of showers and thunderstorms continues on the backside of this front. Temperatures will again be below normal with mostly cloudy skies and a high in the low-80s.
Sunday – showers and thunderstorms cannot be ruled out for Sunday, which will end up being nearly identical to Saturday in sensible weather with high temperatures in the low-80s and mostly cloudy skies.
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.
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
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.
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.
Weather Prediction Center’s Quantitative Precipitation Forecast for total precipitation between 8AM EDT Tuesday and 8AM EDT Wednesday
