The dog days of summer arrive in full force this week before we close out the month of August. With a strong Bermuda high in place well southeast and secondary high pressure in the area, we will see a heat wave take place from today into Thursday. Several days of hot, humid weather are on tap until a cold front moves through Thursday, bringing the potential for strong thunderstorms and much cooler air in its wake.
Rest of today – hot, though not quite as humid as it will be later this week. High temperatures in the low-90s with mostly sunny skies expected.
Tuesday – even hotter, and more humid than today with high temperatures in the mid-90s with sunny skies.
Wednesday – yet another hot, oppressively humid day with high temperatures in the mid-90s. Both Tuesday and Wednesday should see heat index values above 100°F due to high dew point values as well.
Thursday – a cold front is forecast to push through the area Thursday. Along and ahead of this front, we are expecting the chance for some scattered strong to severe thunderstorms given the ample moisture available and hot temperatures. Temperatures will still be hot, in the low-90s, before this frontal boundary passes through. Behind this cold front, temperatures will be 10-15°F cooler Friday into the weekend.
This week starts off hot and humid before we get a break from the humidity as a cold front rolls through late Tuesday. This will be a relatively strong front, and with plenty of moisture in place prior to its passage, bouts of heavy rain are possible with the thunderstorms accompany it. Although high temperatures won’t dip too much following the cold front, dew points will, and this will bring a much drier and more comfortable feel.
Rest of today – hot, humid, with high temperatures in the low-90s. A heat advisory is in effect due to the combination of hot temperatures and high dew points making for an oppressive, muggy day.
Tuesday – increasing clouds, high temperatures in the upper-80s prior to the onset of showers and thunderstorms later in the afternoon, going into the evening hours and overnight. The set up of the atmosphere tomorrow could allow for some marginally severe storms to develop. The primary threat will be from heavy rain and some strong wind gusts given the moisture in place and somewhat favorable shear.
Wednesday – mostly sunny with highs in the mid-80s but more comfortable with dew points significantly lower behind the cold front. Refreshing northerly winds should make for a nice day.
Thursday – another great day with sunny skies and with highs in the mid-80s.
A mostly dry, and pleasant week is in store for us. We will see a steady warming trend, with the only real chance for wet weather happening Wednesday accompanying the passage of a warm front and cold front. Great weather lasts right into the weekend.
Rest of today – cool and sunny with high temperatures below normal in the low-70s due to the influence of easterly onshore winds.
Wednesday – a warm front will approach from the southwest. Ahead of that frontal boundary, we could see chances for mainly stratiform showery rain during the late morning hours. Behind this warm front, expect a humid feeling high in the low-80s with mostly cloudy skies until the arrival of the trailing cold front. This second frontal boundary has a better chance to fire off a few thunderstorms, which could be locally strong, late in the evening and into the overnight hours.
Thursday – high pressure returns and gives us a nice sunny day of high temperatures in the low-80s with westerly winds bringing in warmer air from the interior.
Friday – slightly cooler in the upper-70s to around 80ºF but lots of sun again with high pressure staying in control but shifting east.
The gray, gloomy, and wet weather trend that’s been semi-persistent for much of the last week continues into the weekend. Unfortunately, rain chances will exist both Saturday and Sunday. Cool temperatures to start the weekend will give way to warmer air. Things finally dry out going into the start of next week.
Rest of today – cloudy and cool with temperatures in the mid-60s. Slight chance for showers, though a strong area of high pressure well to our north in Quebec should help hold the line against rain associated with a stationary front draped west-east across Virginia and the Delmarva. Rain chances increase later into the overnight hours as this area of high pressure starts to lift to the northeast.
Saturday – the aforementioned stationary front will start to lift north as a warm front during the day Saturday. Ahead of this warm front, elevated instability could spark a few thunderstorms late in the day with an assist from vorticity maxima moving through in the mid-levels of the atmosphere. Temperatures will be cool, with clouds and rain showers throughout the day, maxing out in the low-60s. These temperatures will actually rise overnight once the warm front pushes through and allows for much warmer air to surge northward.
Sunday – warmer with high temperatures around 80°F, mostly cloudy with chances for showers and a thunderstorm particularly in the afternoon with the passage of cold front.
Monday – weather finally begins to dry up behind this cold front. High pressure will build once again and should give us a nice day with mostly sunny skies and temperatures in the mid-70s.
The story of this week will be the continuation of an unsettled weather pattern from this past weekend. Today, we will see a chance for some severe thunderstorms, and more rain chances lurk for us during the rest of this week, even extending into the weekend. Temperatures during this time will vary between normal and below normal depending on the extent of cloud cover and rain.
Rest of today – warm, humid, with a high in the mid-80s. Chances for severe thunderstorms increasing late in the afternoon. The Storm Prediction Center has placed our area in an enhanced risk for severe thunderstorms, with primary threats being damaging “hurricane force” wind gusts, as well as heavy rain. Some large hail and an isolated tornado are not out of the question. High resolution rapid refresh model simulated radar suggests the best timing of when the storms hit NYC will be around 6PM during the evening rush hour. This will make for a messy road home.
As you can feel already, the air is quite saturated (fog earlier this morning confirms this), this moisture-laden air will be one ingredient fueling storm growth later especially as temperatures warm with cloud-free skies allowing solar heating to quickly destabilize this air mass. At the surface, a cold front slowly approaching from the north and west will serve as the trigger that provides the lift necessary for storms to initiate late this afternoon. Aloft, the presence of a mid-level shortwave trough upstream of us will help prime the atmosphere, increasing lapse rates and instability aloft, while providing some additional divergence and lifting for storms. Lastly, late in the day, we will be in the right entrance region of a 300 mb jet streak, another favorable ingredient for divergence and synoptic lift. Winds at all levels above the surface will be fairly strong, producing a shear profile that favors strong winds. However, any discrete storms that form ahead of the main squall line could contain strong rotating updrafts favoring large hail and tornadoes. As usually, best chances for severe weather exist north and west of the city, away from the stabilizing influence of the marine layer near the coast. Storms will likely weaken as they hit NYC precisely due to this.
Wednesday – will be significantly cooler behind the cold front with high temperatures only in the mid-60s. Rain chances continue as the frontal boundary stalls and becomes stationary just to our south, in a similar arrangement to what took place over the weekend. This pattern looks to lock in for the rest of the week, bringing multiple chances for rain with it.
Thursday – a drier day mostly, with some slight chance for showers in the morning, then mostly cloudy with high temperatures rebounding into the upper-70s. Rain moves back in again overnight going into Friday.
Friday – cooler again with temperatures dipping into the mid-60s. Mostly cloudy with more chances for rain during the day as the stationary front mentioned above pushes back north as a warm front.
The National Hurricane Center announced that Tropical Depression Eighteen has formed over the northwestern Caribbean Sea just south of Isla de Juventud in Cuba. The formation of TD Eighteen has implications on the forecast for Sunday’s storm as a complex scenario is set to unfold.
Impacts: forecasters are anticipating a high wind, and heavy rain event coming up. Storm total rainfall of 2-4″ and possibly higher could lead to urban and small stream flooding. The amount of rainfall over a short period of time has led our local forecast office to issue flash flood watches for much of the region. Winds will pick up as well, backing from the south to southeast, east, and eventually to north and northwest. Wind gusts could become a problem for local airports and for poor travel conditions in general. Thunderstorms are a possibility as well.
Timing: Winds are already increase today, and cloud cover will do so as well as the day progresses. Chances for rain will increase in the overnight hours, probably after 2-3AM. The strongest wind gusts will actually come on the back side of the storm going into Monday as it intensifies and the pressure gradient increases.
Discussion: a complicated set up is unfolding with a longwave trough (on the left) draping from the Great Lakes into the Gulf of Meixco interacting with a developing closed low over the Tennessee Valley, and TD Eighteen. TD Eighteen is likely to strengthen into a tropical storm, which would be named Phillippe if it did form. The effect of this will be to provide a conveyor of warm and moist air from the tropics up to our area. This will help feed the developing non-tropical low forming over the southeast. This low will become the primary rainmaker, and the tropical system (whether a depression or storm) will eventually merge with it. Plenty of instability to fuel a growing storm! The pressure gradient will tighten as this storm strengthens and departs eastward, and that will be the reason for a gusty start to the work week.
The unofficial end of summer does indeed bring us a last gasp of summery weather. A cold front passing through mid-week brings rain and signals a return to more fall-like conditions. Later in the week, we will see high temperatures 5°F below normal. Turning towards the tropics, the risk Irma poses to our region is diminishing, but it now appears Irma will be a threat to Florida.
Rest of today – clear, with ideal conditions for outdoor activities of all kinds. High temperatures in the low-80s.
Tuesday – highs in the low-mid 80s as warm air surges ahead of an advancing cold front. Mostly sunny with increasing clouds late in the day. Some possibility for a spot shower or thunderstorm in the afternoon.
Wednesday – thunderstorms are possible overnight Tuesday as the leading edge of the cold front advances through the area. More rain is expected to ride along the frontal boundary after it passes through, bringing periods of showers throughout the day. High temperatures will be much cooler in the mid-70s with the clouds and rain.
Thursday – mostly cloudy to start with a chance for lingering rain. High temperatures will be cool again in the low-70s.
Friday – mostly sunny skies, much improved conditions as high pressure takes hold. Cool, with high temperatures in the low-70s.
Hurricane Irma an Increasing Threat to Florida
Over the weekend, Irma has been fluctuating in strengthen as it has negotiated marginal conditions for strengthening (mostly the influence of some dry air at upper levels). The National Hurricane Center still forecasts Irma to attain Category 4 strength at some point later this week (130 mph sustained winds or higher) as it encounters more favorable conditions for strengthening, and maintain at least Category 3 strengthen (sustained winds > 115 mph) throughout the forecast period.
The track forecast for Irma has continuously shifted west and south over the weekend due to the influence of an area of high pressure over the Atlantic now, and a faster forecast for the passage of the cold front mentioned above. This frontal boundary lifting out of the East Coast at a faster rate than in prior forecasts would mean that it does not influence Irma to make a turn to the north-northwest and threaten the East Coast. This has two consequences: 1) The chance for Irma to make landfall up the East Coast is diminishing, 2) On the other hand, the risk to Florida is increasing.
This run of the GFS forecast model suggests Irma making landfall on South Florida as a powerful Category 3 hurricane in one week’s time.A “spaghetti” plot of multiple model runs of GEFS, one of the forecast models that forecasters are using to analyze Irma.
It is important to note that with a week to go before Irma nears the US mainland, there could still be room for changes to the track and intensity forecasts. The National Hurricane Center specifically cautions against drawing premature conclusions about the storm’s impact on the rest of the US, while singling out Florida as an area of concern. More updates to come as we continue to watch the development of what could be a very dangerous storm.
We’re well on pace to hit the low-90s again today, which would officially mark the first heat wave of 2017. The Bermuda high that led to these sultry conditions allowed us to heat up even more than official National Weather Service forecasts called for. Temperatures ranged 20ºF above normal in many places away from south facing shorelines. The weekend sees a drastic change in airmasses and a return to more seasonable conditions before the next chance for rain Monday.
Rest of today – hot, humid, high temperatures reaching the low-90s for most areas again except the south-facing shorelines of Long Island. Air quality has improved today so no alert is active. A cold front passes through the area later this evening, with a chance for isolated thunderstorms.
Saturday – the passage of the cold front late Friday sets the stage for a dramatic shift in airmasses. Behind the cold front, a high pressure center over Canada will bring much cooler air riding winds from the north and northeast. Temperatures Saturday are expected to cool off into the upper-60s, with much drier conditions and mostly sunny skies.
Sunday – another cool day with temperatures in the mid-60s and clouds building ahead of a warm front that will move through Monday.
Monday – a warm front, followed quickly by a cold front pushes through Monday. The result will be mostly cloudy skies and an extended period of showers through the day. Temperatures will be slightly warmer, in the low-70s.
Enjoy the spring like temperatures while they last. A strong cold front is set to pass through the area late Saturday. Behind this front, temperatures will return to the low-50s, and perhaps colder. Looking ahead for the next week or so, it appears we will see a cyclical pattern of warm weather ahead of storm systems followed by a rush of colder air.
Rest of today – mild, clear skies, high temperatures have already hit nearly 70°F. Overnight, temperatures drop into the low-50s.
Saturday – still quite warm, near 60°F, but with overcast skies and chances for precipitation ramping up through the afternoon hours. A line of moderate to heavy rain is expected to pass through sometime in the early evening hours. Some thunderstorms may be possible with this line of storms.
Sunday – behind this cold front Saturday, temperatures crash back to normal in the mid-40s wtih sunny skies.
Monday – slightly warmer, mostly sunny, with high pressure in control. High around 50°F.
We’ve been able to enjoy a very comfortable week of summer weather. High temperatures have been largely held in check in the low-mid 80s this week. This weekend, there will be a chance for some rain Saturday, but Sunday will be another nice day with mostly sunny skies and high temperatures in the mid-80s.
Rest of today – mostly sunny, high around 85ºF.
Saturday – watching for the risk of scattered strong to severe thunderstorms tomorrow. The degree of severity will hinge upon how much cloud cover there is during the first half of the day, and whether any storms pop up early. If there are more clouds early, and some storms show up early, the available energy for storms in the afternoon associated with a cold front will be limited. Ahead of this cold front, warm, humid air will flow in, and temperatures should peak near 90ºF.
Sunday – skies will clear quickly following the passage of the aforementioned cold front. High pressure begins to take over and will give us a nice, sunny day, with highs in the mid-80s.
Monday – almost a clone of Sunday with mostly sunny skies and highs in the mid-80s.
Tuesday – with high pressure still almost directly overhead, we will get another nice day with highs in the mid-80s.
Slight Improvement in Drought Conditions
With recent rounds of heavy rain and thunderstorms that have impacted the area, we’ve seen a slight improvement in drought conditions, but the situation is still far from desirable.
