Premium Weekly Outlook 5/9 – 5/14: More sunshine and warmer temperatures
The omega block pattern that supported that the cool, cloudy wet weather for most of last week, is breaking down. More days with sunshine and warmer temperatures are likely this week, with high pressure or confluence underneath an upper-level low over Southeast Canada, keeping frontal boundary mostly south of the region. But an -EPO block developing this week may eventually lead some wet weather to return at the end of this week and the start of next weekend. More technical details on the weather will be discussed below.
First off, today will be a beautiful day. High pressure and confluence from the upper-level low over Southeast Canada will keep a frontal boundary to the south of our region. More high to mid-level clouds over Central and Southern New Jersey are expected to remain closer to the frontal boundary, while sunshine dominates farther north over Northern NJ and NYC. West-southwest winds and deep mixing between 750mb and 800mb will cause temperatures to rise into the lower to middle 70s this afternoon. Breezy conditions also likely this afternoon with wind gusts to near 35mph possible. These winds will also likely hold off any sea-breeze to later in the afternoon, so many coastal locations will see warm temperatures as well.
The NAM showing lower 70s with west-southwest winds on Monday in the region
Tonight, a weak cold front or boundary will push south through the region. This will cause temperatures to drop back into the 40s and possibly even the 30s over the Lower Hudson Valley tomorrow night. No rain is expected from this front. Skies are likely to remain partly cloudy for the rest of the night.
Tuesday’s weather is likely to be more variable, especially throughout our area. A weak wave of low pressure moving along the frontal boundary to our south will cause clouds to push farther north than they did on Monday. Some light showers are possible over Central and Southern New Jersey. Further north, high pressure and the aforementioned confluence zone, which was also present on Monday, will lock in drier conditions. This will cause a wide range in temperatures tomorrow, depending on sky conditions. Cloud cover and showers will keep temperatures in the 50’s across Central NJ while temperatures warming into the 60’s under full sun will produce warmer and more pleasant weather farther north.
The NAM showing showers over Central and Southern NJ Tuesday afternoon with frontal boundary to the south. Temperatures range from 50s south to 60s further north
On Wednesday, clouds will break up for sunshine as high pressure will builds back into region. Temperatures will reach the upper 60s to lower 70s. Thursday could be even warmer with temperatures in the lower to middle 70s. Sea-breezes or light onshore winds with a high pressure east of region could keep coastal locations somewhat cooler during the afternoon and early evening hours. But both days will feature more dry, pleasant weather for the entire region.
GEFS showing an -EPO block over Alaska causing a trough to dig into the Upper Midwest/Great Lakes region later this week. Heights build over Northeast has as the upper-level low moves out of Southeast Canada.
An EPO ridge and block, developing in the Pacific Northwest and British Columbia, will then cause a trough to close off and amplify in the Great Lakes later this week. This will cause height rises over the Northeast and Mid-Atlantic region on Friday. At the surface, a cold front will move across the region on Friday with a good chance at some showers. Some thunderstorms are possible with some instability (lapse rates and CAPE) ahead of this front, but organized severe weather is not anticipated at this time, with model guidance currently showing a notable lack of deep-layer shear for storm organization. Temperatures on Friday will reach into the upper 60s and lower 70s depending on amount of clouds before showers arrive.
GFS showing showers and possible thunderstorms with a cold front and shortwave trough approaching the region on Friday
At this point, this upcoming weekend looks warmer to start. Mid-level heights will lower on Saturday as the upper-level low starts to head east out of Great Lakes. Another cold front could move through the region on Saturday evening with more showers and thunderstorms later in the day. However, a southwest flow and some sunshine ahead of this front may help temperatures rise into the 70s again.
Behind this cold front is another airmass with slightly cooler than normal temperatures arrives on Sunday. Temperatures might drop into lower to middle 60s for highs and lower to middle 40s for lows, butt dry conditions and more sunshine will likely return with high pressure building into region as the weekend comes to a close.