Estimates of Thunderstorm Precipitation Efficiency from Field Measurements in CCOPE

Fankhauser, J. C.

doi:10.1175/1520-0493(1988)116<0663:eotpef>2.0.co;2

Cited by 65 publications

(60 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unfortunately, prior observational studies have struggled with identifying whether a relationship between PE and CAPE exists in the real atmosphere. Marwitz (1972) and Fankhauser (1988) found no clear relationships between CAPE and PE of isolated storms. Statistically insignificant linear correlations between CAPE and PE have also been found in studies of warmseason mesoscale convective systems (Market et al 2003) and squall lines (Takemi 2007).…”

Section: Implications For Precipitationmentioning

confidence: 98%

“…However, maximum rainfall rates at the surface do not necessarily exhibit the same linear trends as CAPE increases, either in simulated storms (e.g., Fig. 6 of McCaul et al 2005) or their observed counterparts (e.g., Marwitz 1972;Fankhauser 1988). It is also not clear how the strength of a storm's lowlevel rotation is influenced by deep-layer CAPE, although there is evidence suggesting that CAPE in the 0-3-km AGL layer may be related a storm's ability to produce tornadoes (Rasmussen 2003).…”

Section: Introductionmentioning

confidence: 94%

“…14). It would have been impossible for Fankhauser (1988) to diagnose this relationship at similar values of CAPE, as only 2 of the 7 cases in his study involved storms in environments with CAPE above 1800 J kg 21 .…”

Section: Implications For Precipitationmentioning

confidence: 99%

See 2 more Smart Citations

Sensitivities of Simulated Convective Storms to Environmental CAPE

Kirkpatrick

McCaul

Cohen

2011

Monthly Weather Review

View full text Add to dashboard Cite

A set of 225 idealized three-dimensional cloud-resolving simulations is used to explore convective storm behavior in environments with various values of CAPE (450, 800, 2000, and 3200 J kg 21 ). The simulations show that when CAPE 5 2000 J kg 21 or greater, numerous combinations of other environmental parameters can support updrafts of at least 10 m s 21 throughout an entire 2-h simulation. At CAPE 5 450 J kg 21 , it is very difficult to obtain strong storms, although one case featuring a supercell is found. For CAPE 5 800 J kg 21 , mature storm updraft speeds correlate positively with strong low-level lapse rates and reduced precipitable water. In some cases, updrafts at this CAPE value can reach speeds that rival predictions of parcel theory, but such efficient conversion of CAPE to kinetic energy does not extend to all storms at CAPE 5 800 J kg 21 , nor to any storms in simulations at lower or higher CAPE. In simulations with CAPE 5 2000 or 3200 J kg 21 , the strongest time-averaged mature updrafts, while supercellular in character, feature generally less than 60% of the speeds expected from parcel theory, and even the strongest updraft found at CAPE 5 450 J kg 21 fails to reach that relative strength. When CAPE 5 2000 J kg 21 or more, updrafts benefit from enhanced shear, higher levels of free convection, and reduced precipitable water.Strong low-level shear and a reduced height of the level of free convection correlate closely with low-level storm vertical vorticity when CAPE is at least 2000 J kg 21 , consistent with previous findings. However, at CAPE 5 800 J kg 21 , low-level vorticity shares the same correlations with the environment as updraft strength. With respect to storm precipitation, in simulations initiated with only 30 mm of precipitable water (PW), all of the storms that last for an entire 2-h simulation tend to produce liquid precipitation at roughly similar rates, regardless of their CAPE. In environments where PW is increased to 60 mm, storms tend to produce the most rainfall at CAPE 5 2000 J kg 21 , with somewhat lesser rainfall rates at lower and higher CAPE. Nevertheless, over the simulation domain, the ground area that receives at least 10 mm of rainfall tends to increase as CAPE increases, owing to a greater number and size of precipitating updrafts in the domain.

show abstract

Section: Implications For Precipitationmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 94%

See 1 more Smart Citation

Sensitivities of Simulated Convective Storms to Environmental CAPE

Kirkpatrick

McCaul

Cohen

2011

Monthly Weather Review

View full text Add to dashboard Cite

show abstract

“…So how can we possibly get more than an inch of rainfall? The efficiency of rainfall mechanisms is not that great, perhaps 30% (Fankhauser 1988;Ferrier et al 1996), as not all storm-ingested water vapor is converted to precipitation and it is not possible to dry out the air completely. Instead, the relative humidity of the air left behind is typically about 70% overall as there are dry downdrafts but also moist cloud debris that remain.…”

Section: Factors Involved In the Charac-teristics Of Precipitation Mmentioning

confidence: 99%

The Changing Character of Precipitation

Trenberth¹,

Dai²,

Rasmussen³

et al. 2003

Bulletin of the American Meteorological Society

2,527

1,803

View full text Add to dashboard Cite

As climate changes, the main changes in precipitation will likely be in the intensity, frequency, and duration of events, but these characteristics are seldom analyzed in observations or models. Why does it rain? If a parcel of air rises, it expands in the lower pressure, cools, and therefore condenses moisture in the parcel, producing cloud and, ultimately, rainfall-or perhaps snowfall. So a key ingredient is certainly the many and varied mechanisms for causing air to rise. These range from orographic uplifting as air flows over mountain ranges, to a host of instabilities in the atmosphere that arise from unequal heating of the atmosphere, to potential vorticity dynamics. The instabilities include those that result directly in vertical mixing, such as convective instabilities, to those associated with the meridional heating disparities that give rise to baroclinic instabilities and the ubiquitous fronts and low and high pressure weather systems. Thus cold air AFFILIATIONS: TRENBERTH, DAI, RASMUSSEN, AND PARSONS-The

show abstract

“…The precipitation efficiency (defined as the ratio of water vapor mass that enters a storm to the condensed water mass that exits the bottom of the storm averaged over the storm's lifetime) can range from ∼ 20-90%, with values of 40-60% being typical for thunderstorm complexes and squall lines (e.g., Hobbs et al, 1980;Gamache and Houze, 1983;Fankhauser, 1988;Chong and Hauser, 1989;Ferrier et al, 1996). On Jupiter, condensates coagulate rapidly into large droplets (Rossow, 1978;Carlson et al, 1988;Yair et al, 1995), and the large diameter of jovian storms would help to inhibit detrainment of condensate out the sides of the storm, which would lead to larger precipitation efficiencies than typically occur on Earth.…”

Section: Semiquantitative Modelmentioning

confidence: 99%