Severe Storm Discernment - to consider
the utility of TLI in the proper discernment of severe vs non-severe
thunderstorms.
Local intentions will be centered around:
a) Pulse Storms...(warm season/weak vertical shear)
b) Storms within Tropical Cyclone Rainbands...(TC tornadic threat)
ACTION:
For Pulse Severe vs non-Severe Storms - AMU meteorologist
will monitor select thunderstorms within MLB's county warning area which
have the potential to become severe (pulse severe - large hail and/or damaging
wind) during the warm/wet season. TLI flash rates (as viewed on LISDAD)
will be assessed through pop-up boxes to make application of a pre-defined
flash rate threshold. Thunderstorms with associated flash rates which exceed
(in particular...those which well-exceed) 120 LDAR flashes per minute
should be regarded suspect as "severe" (current NWS definition...expect
large hail & damaging wind), especially if the flash rate has experienced
a recent significant trend increase. Information will be passed along to
the warning meteorologist to be factored into the warning decision (thus
contrasted against traditional radar signatures for pulse-severe thunderstorm
identification).
Remember, the refresh rate for LDAR data is every "one" minute where
as the WSR-88D data refresh rate is every "five" minutes.
(Be sure to make the proper flash rate determination...check the
multiplication factor to the left of the scale/y-axis (FPM/xx)
on the pop-up box. See example.)
For Tropical Cyclone Rainband Tornadic vs non-Tornadic Storms -
AMU meteorologist will monitor convective rainbands (both inner-band/eyewall
& outer-band) which are in proximity of central Florida for the existance
of electrical activity.
-
Inner-bands / eyewall...when any electrical activity (TLI) is
observed within these bands, the tropical cyclone should be examined for
signs of strengthening. Information should be passed along to the Tropical
Prediction Center.
-
Outer-bands...when any electrical activity (TLI) is observed
within these bands, individual convective cells should be closely monitored
on radar for signs of tornadogenesis.