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Aircraft measurement of the probability distribution of precipitation rate and liquid water content in the hurricane. R. A. Black J. Hallett AOML, Miami, FL DRI Reno, NV. Typical WP-3D Flight Tracks. From Marks_et_all_1992. High RR Storms. Storm A has almost all convective precip
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Aircraft measurement of the probability distribution of precipitation rate and liquid water content in the hurricane R. A. Black J. Hallett AOML, Miami, FL DRI Reno, NV
Typical WP-3D Flight Tracks From Marks_et_all_1992
High RR Storms • Storm A has almost all convective precip • All others used standard flight pattern • Storm B was SS Cat-4 during observation
Low RR Storms • These storms had little high RR • Storms were sampled normally • 90% RR < 20 mm hr-1 • Long tail shows high RR eyewall was penetrated.
Recent Storms • 90% RR < 20 • Tail at large RR nearly flat, smaller range. • Strong Eyewall reflectivity avoided
HotPlate Raingauge • Max RR 70mm hr-1 • Exposure: • 10 m elevation • 300 m from sea • Clear toward SE - N • Shielded N-E by building • Max Power 1000 W
Hotplate Raingauge • Data from Aug. 11 - Oct. 14, 2008 • Winds normally off the sea • Looks similar to small RR hurricane
Raingauge PDF - Cont. • Humid Tropical Coastal Air • Includes 1 torrential rain event
A Torrential Rain event • This is the extreme event of the period. • Note the rapid increase in accumulation when RR > 50 mm hr-1. • Total 24-hr rain: 161 mm
Reflectivity - High RR • Mean high reflectivity 35 - 45 dBZ • Shallow slope on low reflectivity side • Cum. Dist. Doesn’t reach 100% because data < 0 dBZ are included
Low RR storms • Mean reflectivity 30 - 35 dBZ • Peak reflectivity < ~50 dBZ • Storms mostly steady - state
Recent Storms • Median reflectivity < 30 dBZ • Peak reflectivity < 50 dBZ • High reflectivity area avoided
Conclusions • Choice of flight path impacts data • Low RR Hurricane rainfall is similar to Coastal Miami, FL summer rain • PDF can be used to compare model result to observations • Changing rainfall climatology should be detectable