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Milder air will give way to rain, storm threat

A relentlessly active pattern continues as we make our way into the latter half of February. Despite warmer air moving into the area on Thursday and Friday, a significant storm system in the Central United States will move northeastward towards the Great Lakes and drag a cold front through the area later on Friday. The weather on Thursday, in sensible terms, will be much milder than usual with temperatures both aloft and at the surface increasing and plenty of sun expected. We’ll consider it a bit of a consolation prize for the volatility of the pattern over the last several weeks. High temperatures are expected to reach close to 50 degrees in many locations (although cooler near the shore, as usual for this time of year) which will feel almost balmy compared to what we’ve become accustomed to.

Friday, however, looks to be another active weather day in the area with multiple hazards. First and foremost, the Storm Prediction Center has placed parts of Central and Southern NJ in a Slight Risk for severe thunderstorms. As mentioned above, a cold front will move through the area later on Friday. Increased forcing/lift along this front will act as an impressive trigger for storms — and southerly flow ahead of the front will likely provide adequate instability for at least elevated thunderstorms in those areas. A very impressive mid and low level jet just above our heads provides the potential for strong winds to mix down to the surface in any thunderstorms. Although widespread strong/damaging winds aren’t expected, a few severe gusts seem likely but will remain isolated. The threat drops off farther north where instability is less, although rumbles of thunder and heavy rain are still likely along the front.

Hazards overview for Friday, February 21 2014.

Hazards overview for Friday, February 21 2014.

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PM Update: Scattered storms, unsettled Monday

After a weekend of heat (temperatures over 90 degrees since last Thursday in many locations), scattered showers and thunderstorms have developed this evening throughout the area. The main organized severe weather threat remained to our north, over New England, where better shear allowed for more widespread organized severe thunderstorms. Despite plenty of sun and instability in our area, storms have had trouble developing and becoming organized. Forecast models, however, are insistent that storms — and areas of steady rain — will develop from Sunday evening through Monday as the front slows near the area.

The unsettled weather, with showers and clouds, is expected to continue into Monday as the warm and humid airmass gets washed away. The news is not all bad, however — after the front passes Monday evening, a seasonal airmass will move into the area. This will bring with it the return of highs in the mid 70’s and lower humidity with pleasant weather in the forecast through the upcoming work week.

Things will gradually warm up again by the end of the week, with warm air advection bringing a chance of some showers into the forecast as well. Stay tuned for more updates and details as the week moves along. Have a great Sunday evening!

Update: Slight Risk of severe storms from SPC

The Storm Prediction Center has placed parts of Northern New Jersey, Southeast New York ,Connecticut, and the New York City Metro Area in a “Slight Risk” for severe thunderstorms Wednesday afternoon and evening. The “Slight Risk” category is triggered by probabilities of severe weather within 25 miles of a point — and in this case the SPC indicates a 15%-30% chance of severe storms within 25 miles of any point in that area.

Scattered thunderstorms are expected to develop over Pennsylvania and New York later this afternoon before moving into Western New England and Southeast New York. The storms may then eventually drop south and east towards Northern NJ and New York City. However, confidence is higher in the potential for storms to the north of our area. Here, better shear and instability parameters are juxtaposed to support organized severe thunderstorm potential. One forecast model, run for the Storm Prediction Center, suggests the storms may move farther south — into Northern NJ and NYC ( see below ).

SPC-WRF model, forecasting strong thunderstorms impacting the NYC Area Wednesday evening.

SPC-WRF model, forecasting strong thunderstorms impacting the NYC Area Wednesday evening.

After a warm front passed the area this morning, southwesterly winds ushered in a much warmer and more humid airmass. So, the potential exists for the strong storms to move into the NYC Area later this evening despite the fact that the better support for severe weather remains to the north.

Stay tuned for updates on potential watches and warnings from the National Weather Service through the afternoon (this post will be updated).

Severe storms an isolated possibility on Friday

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