
MESOSCALE DISCUSSION 1434
NWS STORM PREDICTION CENTER NORMAN OK
0436 PM CDT FRI JUL 23 2010
AREAS AFFECTED...LOWER HUDSON VALLEY / NYC METRO
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 521...
VALID 232136Z - 232230Z
SEVERE POTENTIAL IS INCREASING ACROSS THE LOWER HUDSON RIVER VALLEY
AND INTO THE NYC MEGALOPOLIS. MAIN THREATS WILL LIKELY BE DMGG
WINDS BUT AN ISOLD TORNADO IS POSSIBLE...A WW WILL LIKELY BE NEEDED
WITHIN THE HOUR.
RECENT SURFACE ANALYSIS PLACES A WARM FRONTAL ZONE EXTENDING FROM
LONG ISLAND WNWWD TOWARDS NERN PA. THE AIRMASS S OF THIS BOUNDARY
IS CHARACTERIZED AS VERY MOIST/UNSTABLE. RADAR MOSAIC IMAGERY OVER
THE PAST 30 MINUTES SHOWS A DEVELOPING SUPERCELL OVER SUSQUEHANNA
COUNTY PA AND THIS WILL LIKELY MOVE SEWD ALONG THE INSTABILITY
GRADIENT. RELATIVELY BACKED SLY LOW LEVEL FLOW VEERING TO STRONG
WNWLY MID LEVEL FLOW IS CONTRIBUTING TO SUBSTANTIAL LOW LEVEL SHEAR
/IN EXCESS OF 300 M2/S2 0-1 KM SRH/. AS SUCH...A WW WILL LIKELY BE
NEEDED WITHIN THE HOUR TO ACCOUNT FOR A DMGG WIND THREAT AND
INCREASING TORNADO POTENTIAL.
..SMITH.. 07/23/2010
Sign In
Create Account

Back to top










