Forecast Highlights: A strong mid-level shortwave trough accompanied by a surface low pressure is expected to track through the region this evening, bringing the potential for strong to severe thunderstorms mainly west of NYC late …
2:15 PM: Storm Risk Continues Today, Tomorrow Upton, NY radar imagery from 1911 UTC (3:11 PM EDT), from the College of DuPage. As of this afternoon, a weak cold front is progressing east through the …
Forecast Highlights: A short range shift in the forecast is increasing the likelihood of a wet and chilly 4th of July in NYC, as a wave of low pressure develops farther north than previously forecast …
A strong mid-level shortwave trough accompanied by a surface low pressure is expected to track through the region this evening, bringing the potential for strong to severe thunderstorms mainly west of NYC late today, capable of producing strong to damaging wind gusts. A weak high pressure will return for Friday through Monday, providing sunshine but gradually warming temperatures ahead of the next frontal passage by the middle of next week.
2:15 PM: Storm Risk Continues Today, Tomorrow
Upton, NY radar imagery from 1911 UTC (3:11 PM EDT), from the College of DuPage.
As of this afternoon, a weak cold front is progressing east through the tri-state area, and is currently positioned over northeast NJ. The environment ahead of this cold front is modestly unstable with CAPE values above 1500 J/kg, supporting the persistence of scattered thunderstorms along the cold front generally tracking towards the ESE. There is a line of heavy thunderstorms currently extending from Clifton, NJ through Paramus, NJ and Rockland county in NY, tracking ESE towards northern Manhattan, Bronx and southern Westchester counties towards 2:30 PM. Another area of scattered thunderstorms is concentrated near Stamford, CT (Fairfield) as well as just west of New Haven, CT. The current environment is not conducive for severe thunderstorms with a lack of strong vertical wind shear, with heavy rainfall up to 1/2 inch the primary risk given a very moist environment with precipitable water values near 2 inches. Most of the storms are likely to end towards 4-5 PM as the front continues to slowly progress east.
A slightly higher risk of strong to locally severe thunderstorms is possible on Thursday as a stronger mid-level shortwave trough and accompanying surface low pressure track through the area during the evening hours. While a very moist environment will persist with precipitable water values well over 2 inches, once again contributing to a heavy rain risk, stronger vertical wind shear is anticipated given the mid-level wind maximum accompanying the shortwave trough, up to 45-50 knots at 700 hPa, along with a low-level directional shear component, favoring the potential for strong wind gusts over 40-50 mph primarily west and south of NYC. More information will be posted later tonight or on Thursday morning.
A short range shift in the forecast is increasing the likelihood of a wet and chilly 4th of July in NYC, as a wave of low pressure develops farther north than previously forecast with rain spreading through the tri-state area on Saturday. A brief period of drier and warmer conditions is expected for Sunday and Monday before the potential for thunderstorms increases again towards the mid and late week period.
Severe thunderstorms occurred yesterday in eastern Pennsylvania, concluding with a squall line that progressed through the tri-state area early today with heavy rain and wind gusts over 40 mph. With the upper level trough departing this morning, drier conditions will return through the late week and weekend, with temperatures gradually rebounding into the mid to upper 80s into early next week before the next potential for thunderstorms.
After an unseasonably strong low pressure system produced a widespread 1 to 2 inches of rain across the region on Saturday, an upper level trough persists over the eastern half of the US but with a gradual warming trend continuing as temperatures return into the 80s for the majority of the upcoming week.
A strong shortwave trough will progress through the region today, resulting in strong to severe thunderstorms over western NJ into Pennsylvania, with additional rain possible on Wednesday before a drier ending to the week.
Heat and humidity made a brief return to the region ahead of a strong cold front on Tuesday, producing severe thunderstorms in New Jersey, Long Island and New England but largely bypassing western parts of the tri-state area. Warm temperatures will not last for long, however, as an anomalously strong ridge becomes stationed over the western US placing the region under a cooler than average pattern with frequent rain events over the next week.
A strong cold front will progress through the region today, accompanied by a strong mid-level jet streak and a warm and unstable air mass to produce scattered strong to severe thunderstorms, capable of producing strong to damaging wind gusts and an isolated tornado risk later this afternoon. This will be the last summer-like outbreak for a while, as a trend towards an anomalously strong northeast US trough may result in a much colder and wetter ending to the week more typical of spring than late June.
The remnants of Tropical Storm Bill, the second named storm of this year’s hurricane season, passed through the tri-state area last night with substantially less impact than anticipated, with rain totals generally remaining below an inch. Additional isolated storms are possible tonight, but with an otherwise warm and humid air mass lingering through Tuesday, when a cold front may produce severe thunderstorms followed by a cooling trend into the longer range.