7/01/2009

Day 1 Severe Weather Outlook for July 1, 2009

D1 Outlook for Wednesday is complete. Slight Risk will once again be in play for large hail and damaging winds over a good amount of the area. Slight Risk includes the following counties…

New York: Albany, Bronx, Columbia, Delaware, Dutchess, Greene, Kings, Nassau, New York, Orange, Putnam, Queens, Renssalaer, Richmond, Rockland, Schoharie, Suffolk, Sullivan, Ulster, West Chester.

Pennsylvania: Berks, Bucks, Carbon, Chester, Delaware, Lackawanna, Lehigh, Monroe, Montgomery, Northampton, Philadelphia, Pike, Wayne.

New Jersey: Atlantic, Bergen, Burlington, Camden, Cape May, Cumberland, Essex, Gloucester, Hudson, Hunterdon, Mercer, Middlesex, Monmouth, Morris, Ocean, Passaic, Salem, Somerset, Sussex, Union, Warren.

Connecticut: Fairfield, Hartford, Litchfield, Middlesex, New Haven, New London, Tolland, Windham.

Massachusetts: Berkshire, Franklin, Hampden, Hampshire.

Delaware: Kent, New Castle, Sussex.

Maryland: Caroline, Cecil, Dorchester, Kent, Queen Anne's, Somerset, Talbot, Wicomico, Worcester.

Discussion...

Some uncertainty surrounds the amount of instability that will be in play for tomorrow afternoon/evening. Trends will need to be monitored Wednesday Morning to see how well atmosphere rebounds following overnight convective remnants that are rotating about much of the region. Risk areas will likely need to be tweaked in Late Morning update once amount of destabilization is better discerned. Also may need to expand a bit further south into Delmarva/Eastern Va area.

Current thinking is that MLCAPE values will likely range from 1250-2000 J/KG over much of the risk area. This area of moderate destabilization will be accompanied by fairly modest Lift and low level Bulk shear, generally in the -3 to -6 and 30-45 kts range, respectively. This will support the initiation of showers and storms over most of the area by Early Afternoon, some of which will likely become severe with large hail/damaging winds along with excessive rainfall and frequent lightning.

Low-level Helicity is once again not strong, but present enough so that tornado threat will once again be non-zero. Therefore, a low 2% probability will also accompany Slight Risk area.

..EGAN..




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