Marine and Coastal Impacts from Imelda; Unsettled Weather in the West

Swells and high surf from both Imelda and Humberto are expected to bring dangerous marine conditions and rip currents to much of the East Coast over the next several days. A series of Pacific frontal systems will bring waves of showers and thunderstorms to portions of northern California and the Pacific Northwest through midweek. Read More >

Overview

In the wake of a cold front resulting from the remnants of Hurricane Beryl, a convective severe weather threat existed for North-Central, Central, and South-Central PA.

Straight-line wind gusts were the primary impact, though radar-indicated tornadoes/circulations were present over North-Central PA. A mid-level cap (milder air aloft), despite all other severe weather parameters being in place, kept the storms shorter and storms weaker.

Courtesy: NWS SPC

SPC Mesoscale Convective Discussions

MCD #1569

Courtesy: NWS SPC

MCD #1571

Courtesy: NWS SPC

MCD #1573

Courtesy: NWS SPC

Radar
Storm Reports
Environment

Radar


The first line of convection initiated around 11:00 AM EDT (15:00 UTC) roughly 100 miles East of the cold front.	Peak tornadic activity took place around 2:30 PM EDT (18:30 UTC), though most of this occurred in upstate NY.	Near Landisburg, KCCX imagery showed a MARC (Mid-Altitude Reflectivity Convergence) signature indicative of strong downbursts.

Storm Reports

Environment

Figure 1: The strong cold front associated with post-tropical storm Beryl is seen in the 18z surface analysis. The line of convection is indicated as a squall line in this analysis.

Courtesy NWS WPC

Figure 2: The cold front moved Eastward.

Courtesy NWS WPC

Near-storm environment summary.