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Massive Heat Wave; Severe Storms and Heavy Rain

A massive heat wave is consuming much of the Midwest into the Southern tier of the U.S. with hazy, hot and humid conditions. These dangerous conditions will likely persist through Thursday as widespread excessive heat warnings and heat advisories are in effect. North and east of the heat and area of high pressure, thunderstorms with damaging and severe winds, large hail and heavy rain are likely. Read More >

Public Information Statement
National Weather Service Baltimore MD/Washington DC
601 PM EDT Thu May 30 2019


Staff from the National Weather Service Baltimore/Washington
Weather Forecast Office completed storm surveys in portions of
the northern Baltimore Metropolitan Area on Wednesday afternoon,
May 29, 2019.

The Fallston and Baldwin area of west-central Harford County was
impacted by a macroburst, which produced damaging wind gusts
estimated at 80-90 MPH. A macroburst is defined by Fujita
(University of Chicago, 1985) as a large downburst with winds
extending in excess of 2.5 miles long. A concentrated area of
damage was observed starting at Moores Road in Baldwin, extending
discontinuously for approximately 3.25 miles to the east, ending
at Pleasantville Road in Fallston. In this area, numerous
observations of tree damage were observed. The tree damage
included mainly large limbs of hardwood trees and snaps of about a
dozen pine trees. Several single family homes were impacted with
limbs falling onto rooftops. All tree damage fell in an easterly
direction, with eyewitness time estimates of occurrence between
600-615 PM. An image circulating among residents showed what
appears to be a roll cloud, representing the leading edge of the
gusty winds. Frequently, roll clouds are mistakingly identified as
a funnel cloud or a tornado, but they lack the laminar,
streamlined condensation cloud of a funnel cloud which would be
attached to the cumulus cloud base. Storm Relative Velocity at the
0.5 degree elevation angle from the FAA`s Terminal Doppler
Weather Radar at BWI Thurgood International Airport clearly shows
a divergent pattern at 610 PM across the region, indicative of a
downburst windfield, which coincides with time estimates by

The other region of the northern Baltimore Metropolitan area that
was adversely impacted by Wednesday afternoon`s severe storms was
the White Marsh region of eastern Baltimore County. This area was
also impacted with a macroburst, which caused straight-line wind
damage. Two wooden telephone poles were snapped along Silver
Spring Road, and numerous trees and branches were downed along
Saxon Circle. All observed tree damage fell to the northeast.
Additionally, the Baltimore County Office of Homeland Security and
Emergency Management reported the easternmost wind damage in
Middle River, near the intersection of Ebenezer and Bird River
Roads. The western most damage reported was near the intersection
of Yvonne Ave and Silver Spring Rd in Nottingham. There were
approximately 18 instances of tree damage between these two
locations, with the horizontal distance of about 4 miles. The
FAA`s Terminal Doppler Weather Radar at BWI Thurgood International
Airport clearly shows a 0.5 degree elevation angle radial
velocity downburst/divergent wind pattern at 555 PM. The snapping
of the telephone poles and nature of the reported and observed
tree damage produces an estimate of 80-90 MPH wind.

The National Weather Service Baltimore/Washington Weather Forecast
Office would like to thank the Harford County Department of
Emergency Services and the Baltimore County Office of Homeland
Security and Emergency Management for their assistance in the
storm surveys.