April 26, 2011: Strong Storms On Thursday

As a much warmer air mass moved into the region, temperatures today were warmer than yesterday, reaching the lower to mid 80s across northern New Jersey, however an onshore wind kept coastal locations with colder temperatures, with 70s and 60s observed in Long Island. This afternoon, severe thunderstorms affected western and central Pennsylvania and New York with strong winds, hail, and a tornado warned storm. Since then, the storms have formed a line but are expected to weaken as they move towards the area. A couple of thunderstorms may be possible tonight, especially west of NYC, however these storms are not expected to be severe by the time that they reach the area, if they do so at all.

A widespread severe weather outbreak is currently ongoing in the southern US, where a High Risk has been issued by the SPC. This is associated with a storm expected to form tomorrow and intensify while moving towards the Great Lakes, pushing the cold front east and finally starting to bring an end to the consistent severe weather in the central and southern US. This cold front will reach the area on Thursday, bringing a risk of strong to severe thunderstorms and heavy rainfall in the evening hours, followed by dry and mainly sunny conditions lasting through next weekend.


Tomorrow's Outlook:

As the storm continues to organize in the southern US while moving north, yet another widespread severe thunderstorm outbreak is expected in the southern US. Unlike today, which brought partly to mostly cloudy skies to the area with dry conditions, tomorrow will bring mostly cloudy skies and scattered showers and thunderstorms, with the best chance of storms in the afternoon and evening hours from NYC and further west, where some storms could be strong, producing heavy rain and gusty winds.

A SSE wind is expected tomorrow, which combined with cloud cover, will bring colder temperatures for the area. Temperautres from NYC and further west are expected to be in the mid to upper 70s, with colder temperatures in coastal sections of NYC. Long Island and southern Connecticut are expected to see highs in the 60s and 50s.


Thursday: Strong/Severe Storms Reach NYC Area

As previously mentioned, the storm in the central US will continue to intensify while moving north, bringing the cold front further east. Timing is expected to be supportive for storms, with thge main line reaching the western and central parts of the area from 2-5 PM. Parameters according to the models are also supportive of some severe weather, with bulk shear up to 60-70 knots and LI up to -4. Cloud cover may be an issue that would limit the severe weather risk from becoming much higher, though there is enough support for strong to potentially severe thunderstorms to affect the region in the late afternoon hours, therefore I placed a 15% risk of severe weather for the western and central parts of the area.

Ahead of the storm, temperatures are expected to warm up into the lower to mid 70s from NYC and further west with mostly cloudy to cloudy skies in place. A squall line is then expected to move into the western and central parts of the area between 2 and 5 PM, with the main risks being heavy rainfall, with up to 1 inch of rain possible in the heavier storms, and gusty winds, with gusts up to 50 mph possible in the stronger storms. As the storms move east of NYC, they are expected to weaken, dropping below severe levels, though they may still be capable of producing heavy rainfall and gusty winds. The storms will end from west to east in the evening hours, with clearing skies overnight.


Friday and Weekend: Dry, Comfortable Weather To Return

This cold front will bring a temporary end to the active weather pattern we have seen for the last several weeks. With mostly cloudy skies and a chance of showers, Friday will bring colder temperatures, only reaching the lower to mid 60s from NYC and further west with even cooler temperatures further east. After a cold Friday night, with low temperatures expected to reach the upper 30s in NW NJ/Orange County, NY, Saturday will bring warmer temperatures, returning into the upper 60s to lower 70s from NYC and further west, along with a WNW wind and mostly sunny skies. A warmer air mass will then return into the area, with Sunday bringing high temperatures in the lower to mid 70s from NYC and further west.

The models are currently split on the longer range, with solutions ranging from simply a cold front moving through to a coastal low developing. Stay tuned for more information as details become clearer.