Cloud Stalker: June 2020

Tuesday, June 2, 2020

Tropical Storm Cristobel

TD Three has strengthened to Tropical Storm Cristobal. Cristobal
is centered near 19.3N 92.7W at 02/1515 UTC or 130 nm WSW of
Campeche Mexico moving SW at 3 kt. Estimated minimum central
pressure is 1004 mb. Maximum sustained wind speed is 35 kt with
gusts to 45 kt. Numerous moderate scattered strong convection is
within 270 nm of the center in the east semicircle and 90 nm
west semicircle, including the Yucatan Peninsula and portions of
southern Mexico. Cristobal is forecast to meander over the
southern Bay of Campeche through Thursday. Additional heavy
rainfall is expected over southern Mexico and northern Central
America, potentially leading to life-threatening flash floods
and mudslides during the next few days. See the latest NHC
forecast advisory at hurricanes.gov for more information.Forecaster Hagen

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.