Severe Weather Potential for Long Island and Also New Images For Laura
Isolated thunderstorms tomorrow afternoon will have the potential to contain damaging wind gusts of 55 to 65 mph. You can see in the 1st and 2nd images that the greater chance is to the southwest of Long Island. The 3rd image is the simulated radar from the NAM model for 5 PM tomorrow just to give a general idea of the timing of the line of storms.
The following is from the Storm Prediction Center:
...SUMMARY... Thunderstorms capable of isolated severe gusts (55-65 mph) resulting in scattered wind damage are probable for portions of the Mid-Atlantic states. ...The Northeast... A strong cold front is forecast to shift across the U.S./Canada border and move quickly eastward across New England, while progressing more slowly southeastward across the Mid Atlantic region and southward across the central Appalachians. Isolated general thunderstorms may be ongoing Tuesday morning and lending some uncertainty regarding destabilization across lower elevations near the coast ahead of this activity. However, west-northwesterly flow in the mid levels is forecast to strengthen during the day across the region and support relatively fast multicell storms. It appears the greatest risk for severe gusts and associated tree/wind damage will occur farther south across parts of eastern PA/NJ into the Chesapeake Bay vicinity. Strong heating and mean mixing ratios in the 15-16 g/kg range, will result in a moderately to very unstable boundary layer by mid afternoon (2000-3000 J/kg MLCAPE). Effective shear 20-30 kt will favor a multicell convective mode supportive of clusters and line segments potentially capable of isolated 55-65 mph gusts and accompanying scattered wind damage.
The 4th image is the new 12Z GFS ensembles (upgraded version) for Laura, and the 5th image is the new 12Z run of the HWRF. The potential continues to exist for a major hurricane to make landfall along the upper coast of Texas or western Louisiana. Uncertainty still exists in both the track and intensity at landfall.