NYC Severe Weather Threat for 26 June 2009

Well after what seems like an eternal wait, New York City is in the middle of a nice big SLGT by the SPC. The beginning of this week was plagued by a pesky upper-level cut-off low parked near Cape Cod, bringing rain showers and below-climo temps to our region. Finally, we have a nice set up for hot summer days and good convection.

The SPC Day 2 outlook right now has NYC under a SLGT, with a 15% categorical outlook. A series of shortwave troughs are expected to help amplify the weak zonal pattern we've had for weeks. SBCAPE should build throughout the day to over 3000 J/kg after 1800 UTC.



This is the NAM's forecast precipitation/pressure/isotherms for 00UTC 27 June 2009. Other more high-resolution models show much more precip, and PWATs are progged to be at least 1.5 inches. Here is the SPC forecast:





Upper level jet dynamics are decent, with a 60-kt jet streak at 250-hPa with NYC being placed in the right entrance region. Strong cyclonic vorticity advection at 500-hPa is present and the GFS is most aggressive with the negative tilting of the trough. Mixing rations of 12+ g/kg are present, so our atmosphere will be nice and moist.

More updates will follow as I try to stay awake.

Severe Weather Just Around The Corner

The next couple of days are looking somewhat favorable for severe weather in NY. At the moment, it does not look like there will be much. Most of the action will depend on the placement of the fronts, which favors western and southern portions of NY at this time. Further north, expect showers and thunderstorms as well, but these storms will be elevated. Strong winds and small hail will be possible with these storms. The GFS has more favorable severe weather conditions further north than the NAM does, but the GFS is bringing the line further and further south as we approach game time.

At any rate, some of NY could get a nice light show from these storms. My camera will be ready.

Also, sorry for only 1 update again this week... been having problems with my computer (I have completely reformatted and reinstalled stuff over the weekend).