Cloud Stalker: Arthur- First storm of the Season

Sunday, May 17, 2020

Arthur- First storm of the Season

Tropical Storm Arthur is near 30.0N 77.6W at 0900 UTC, or about 
303 nm SSW of Cape Hatteras, North Carolina, moving NNE at 8 kt.

Minimum central pressure is 1006 mb and maximum sustained winds 
are 35 kt with gusts to 45 kt. Numerous moderate to strong 
convection is N of 23N between 74W and 78W. On the forecast 
track, Arthur will remain well offshore the east coast of Florida,
Georgia, and South Carolina today, and then move near or just 
east of the coast of North Carolina on Monday. Some strengthening
is forecast during the next 48 hours. Arthur is likely to lose 
its tropical characteristics on Tuesday.

 -Ramos-

No comments:

Post a Comment

HAIL (3/4 inch or greater)

Hail can cause significant damage to your vehicle, break windows and damage roofs of homes and businesses.
Hail can cause significant bodily injuries such as broken bones and even blindness if wind blown.
Softball (4.5 inches) sized hail was reported in Lake Wales, Florida on March 30, 1996.
Haildrifts, up to four feet deep of dime to nickel sized hail, occurred in low-lying areas near Zephyrhills, Florida on January 29, 1997.
Hailstones the size of softballs can fall at speeds faster than 100 mph

supercell

Supercells derive their rotation through tilting of horizontal vorticity (an invisible horizontal vortex) caused by wind shear. Strong updrafts lift the air turning about a horizontal axis and cause this air to turn about a vertical axis. This forms the deep rotating updraft, the mesocyclone.
A cap or capping inversion is usually required to form a downdraft of sufficient strength. The cap puts an inverted (warm-above-cold) layer above a normal (cold-above-warm) boundary layer, and by preventing warm surface air from sinking too far, allows one or both of the following:
Air below the cap warms and/or becomes more moist
Air above the cap cools
This creates a warmer, moister layer below a cooler layer, which is increasingly unstable (because warm air is less dense and tends to rise). When the cap weakens or moves, explosive development follows.
In North America, supercells usually show up on Doppler radar as starting at a point or hook shape on the southwestern side, fanning out to the northeast. The heaviest precipitation is usually on the southwest side, ending abruptly short of the rain-free updraft base or main updraft (not visible to radar). The rear flank downdraft, or RFD, carries precipitation counterclockwise around the north and northwest side of the updraft base, producing a "hook echo" that indicates the presence of a mesocyclone.