NYC Area Forecast: Improving Weather Today, More Unsettled for the Weekend
Good morning! A wave of low pressure that brought some rainfall to region overnight will move further offshore this morning. This will cause any lingering showers to end and skies to clear for sunshine as the morning goes on. This afternoon and early this evening, mostly sunny skies are expected as high pressure over Southeast Canada begins to build south into the region. High temperatures will be very warm with northerly downsloping winds this afternoon–in the mid-upper 80s.
Early tonight, a weak cold front from the north will pass through the region (mostly dry). However, winds will be turning more northeasterly behind this front. This may result in a marine layer with low clouds developing later tonight along some coastal areas. Otherwise, mostly clear skies are expected through tonight. Overnight low temperatures will range from the middle 50s over the Interior areas to middle 60s over NYC and urban areas.
Friday and the Weekend
A closed upper-level low over the Midwest will track through the Ohio River Valley and Great Lakes region this weekend. This low will open up and weaken into a broader trough as it runs into additional confluence over the Northeast US. As a result, we aren’t expecting a washout with widespread or heavy rainfall for either day of the weekend. But this storm system will certainly cause some unsettled weather at times.
On Friday, partly sunny skies are expected, as high clouds begin moving ahead of this next storm system. Onshore easterly winds will also support a maritime airmass over the region, keeping high temperatures in the mid-upper 70s – a few degrees below average for this time of year.
Friday night and Saturday morning, a warm front from this storm system will be lifting slowly northward. Mostly cloudy skies are expected and some scattered showers and thunderstorms are likely, as isentropic lift and elevated instability increases ahead of this front. Sub-tropical moisture streaming along this front with precipitable water values around 1.50″ and higher may support some locally heavy rainfall totals.
3km NAM showing showers and thunderstorms moving Saturday morning over parts of the Northeast
If this warm front moves through, there is a possibly that skies may clear for sunshine during the afternoon or early evening hours, allowing temperatures to rise into the 70s and 80s. However, a weak of wave of low pressure may also develop along this front – acting to keep this front south of NYC metro with clouds and onshore winds remaining in place. As a result, a wide range of temperatures between the 60s and 80s is possible north to south across the region on Saturday.
We will also have to monitor potential for some isolated strong to severe thunderstorms in the warm sector, particularly over parts of the Mid-Atlantic region, later Saturday afternoon and evening. Although weak mid-level lapse rates may mitigate this threat, shortwave energy associated with the storm will interact with at least some moderate levels of instability and shear.
On Sunday, latest model guidance suggests the warm front will continue moving through much of Northeast. This will cause skies to clear for sunshine during the midday hours, with increasing southwest flow. Temperatures are likely to rise into the mid-upper 80s, with humidity increasing as well. A cold front associated with another shortwave trough coming from the Great Lakes will be approaching again during later in the day. As some instability builds from the warmer and more humid airmass, scattered showers and thunderstorms are possible during the late afternoon and evening hours
ECMWF showing high temperatures in the middle 80s over the urban corridor in the Northeast on Sunday
Next Week and Beyond
Some unsettled weather may continue into the middle of next week. A couple more disturbances or frontal systems may move through the Northeast with more showers or thunderstorms. Otherwise, it will be a little cooler and less humid overall once again, as Canadian high pressure settles in. High temperatures will be likely be closer to average, in the upper 70s to lower 80s each day.
Later next week there are signs that troughiness over the Western US may result in the expansion of ridging over the Central and Eastern US. This will support heat and humidity to returning to the Ohio River Valley and the Northeast US by the end of month and into the beginning of July. This is also supported by model and ensemble guidance forecasts for the MJO to propagate into the phases 2/3 during this time frame. More updates come to soon!