The mesoscale measurement challenge can best be met by an integrated approach that considers an end-to-end solution. Background. The development and delivery of accurate, reliable, and useful mesoscale atmospheric forecasts present special needs, challenges, and opportunities that currently are not being met in a consistent and uniform way. As the resolution of atmospheric forecast models has increased, there has been a corresponding, but smaller, increase in forecast skill and utility to end users. The full benefit of enhanced forecast model resolution has not been and will not

A series of rhodium complexes, [Rh(cod)(NHC-F(x))(OH(2))] (cod = 1,5-cyclooctadiene; NHC = N-heterocyclic carbene), incorporating anionic N-heterocyclic carbenes with 2-tert-butylmalonyl backbones and 2,6-dimethylphenyl (x = 0), 2,6-difluorophenyl (x = 4), 2,4,6-trifluorophenyl (x = 6), and pentafluorophenyl (x = 10) N,N'-substituents, respectively, has been prepared by deprotonation of the corresponding zwitterionic precursors with potassium hexamethyldisilazide, followed by immediate reaction of the resulting potassium salts with [{RhCl(cod)}(2)]. These complexes could be converted to the related carbonyl derivatives [Rh(CO)(2)(NHC-F(x))(OH(2))] by displacement of the COD ligand with CO. IR and NMR spectroscopy demonstrated that the degree of fluorination of the N-aryl substituents has a considerable influence on the σ-donating and π-accepting properties of the carbene ligands and could be effectively used to tune the electronic properties of the metal center. The carbonyl groups on the carbene ligand backbone provided a particularly sensitive probe for the assessment of the metal-to-ligand π donation. The ortho-fluorine substituents on the N-aryl groups in the carbene ligands interacted with the other ligands on rhodium, determining the conformation of the complexes and creating a pocket suitable for the coordination of water to the metal center. Computational studies were used to explain the influence of the fluorinated N-substituents on the electronic properties of the ligand and evaluate the relative contribution of the σ- and π-interactions to the ligand-metal interaction.

A complete yearly record (1988) of surface measurements is used to examine the atmospheric diurnal secondary circulations over the entire area of Hong Kong in conjunction with spatial and temporal variations of surface temperature, wind speed and rainfall. Evidence of atmospheric diurnal secondary circulations is found at 10 sites. The occurrence of a summer morning rainfall maximum over the coast results from the interaction ofthe large-scale summer monsoon and local mesoscale secondary circulations. The afternoon onshore secondary circulation accelerates the advection of warm, humid unstable air and, coupled with the upward orographic lifting, produces enhanced rainfall along windward mountain ridges.Dynamical and scaling considerations suggest that the blocking effect is negligible and the primary forcing mechanism is land-sea temperature difference, but terrain effects are also important. Although the secondary circulation system's strength and timing vary the circulation behaves like a classic sea-land breeze circulation, complicated by superimposed mountain-valley breezes.

The 22-23 February 1998 central Florida tornado outbreak was one of the deadliest and costliest in Florida's history; a number of long-track tornadoes moved across the Florida peninsula after 0000 UTC 23 February 1998. In the 12-24 h prior to 0000 UTC 23 February, a vigorous upper-level synoptic system was tracking across the southeast United States, and a north-south-oriented convective band located ahead of the cold front was moving eastward across the Gulf of Mexico. Strong vertical wind shear was present in the lowest 1 km, due to a ϳ25 m s Ϫ1 low-level jet at 925 hPa and south-southeasterly surface flow over the Florida peninsula. Further, CAPE values across the central Florida peninsula exceeded 2500 J kg Ϫ1 . Upon making landfall on the Florida peninsula, the convective band rapidly intensified and developed into a line of tornadic supercells. This paper examines the relationship between a diabatically induced front across the central Florida peninsula and the rapid development of tornadic supercells in the convective band after 0000 UTC 23 February. Results suggest that persistent strong frontogenesis helped to maintain the front and enhanced ascent in the warm, moist unstable air to the south of the east-west-oriented front on the Florida peninsula, thus allowing the updrafts to rapidly intensify as they made landfall. Further, surface observations from three key locations along the surface front suggest that a mesolow moved eastward along the front just prior to the time when supercells developed. It is hypothesized that the eastward-moving mesolow may have caused the winds in the warm air to the south of the surface front to back to southeasterly and create a favorable low-level wind profile in which supercells could rapidly develop.

This paper discusses the application of Micropower Ultrawideband Impulse Radar (MUIR) technology to the detection and monitoring of intracranial hemorrhage. MUIR is ideally suited for medical diagnostic and monitoring applications because the emitted electromagnetic radiation is non-ionizing and has both peak and average power levels that are orders of magnitude lower than those of a hand-held cell phone. Furthermore, MUIR can be readily packaged into handheld, battery operated form factors. There are numerous applications for such a device: rural settings with limited CT access; field use where excessive hemodynamic instability may preclude patient transport; natural disaster or conflict events that require on-site triage; and for hospital bedside monitoring. In experimental phantoms and in a small human subjects study, MUIR technology successfully detects reflected signals from near-surface hematomas. These investigations suggest the feasibility of developing MUIR-based systems for pre-hospital or bedside diagnostic applications to assist with early diagnosis, triage, and treatment planning.