Search Results

You are looking at 51 - 60 of 1,535 items for :

  • Weather and Forecasting x
  • Refine by Access: All Content x
Clear All
Christopher Davis, Wei Wang, Jimy Dudhia, and Ryan Torn

in the 12-km forecasts. These may include some cases where the 34-kt wind radius extended beyond what would reasonably be considered the tropical cyclone circulation due to anomalously strong synoptic-scale surface winds favoring a particular quadrant. It is also likely that these large wind radii would be more consistent with those derived from H*Wind given the results from Moyer et al. (2007) . For the extent of hurricane-force winds ( Fig. 10b ), there is a clear discrepancy at smaller radii

Full access
Ryan E. Lyman, Thomas A. Schroeder, and Gary M. Barnes

Resource Research Center Tech. Rep. 119, University of Hawaii at Manoa, 69 pp . Smolarkiewicz, P K. , Rasmussen R M. , and Clark T L. , 1988 : On the dynamics of Hawaiian cloud bands: Island forcing. J. Atmos. Sci. , 45 , 1872 – 1903 . 10.1175/1520-0469(1988)045<1872:OTDOHC>2.0.CO;2 Szoke, E J. , and Zipser E J. , 1986 : A radar study of convective cells in mesoscale systems in GATE. Part II: Life cycles of convective cells. J. Atmos. Sci. , 25 , 199 – 218 . Tokay, A. , and Short

Full access
Steven E. Koch, Randolph Ware, Hongli Jiang, and Yuanfu Xie

( Thompson et al. 2003 ). b. Mesoscale environmental forcing of convection The vLAPS analyses produced every 15 min on a 1-km grid were used for diagnostic examination of the near- and prestorm environment over the domain shown in Fig. 1a . The context for this discussion begins at the 300-hPa level, as a strong (>50 m s −1 ) upper-level jet (ULJ) streak approached the Windsor CI region ( Fig. 1a ) from the south. With the approach of the ULJ streak, and just before deep convection broke out, winds

Full access
Boniface J. Mils and John E. Walsh

moderate to heavy snow with gale force winds (&gt; 18 m s-i), lightning, and thunder along a narrowtrack approximately ! 500 km in length. The mesoscale vortex resembled the so.called "polar lows" that formover the subpolar seas. The similarities include development on the cyclonic-shear side of a long-wave trough,strong positive vorticity advecfion associated with a 500 mb short-wave trough, upstream tilt of the geopotentialheights, conditional instability in the lower troposphere, a southeastward

Full access
B. W. Buckley and L. M. Leslie

operational numerical model output, investigates the potential for suitably configured high-resolution models to provide the necessary detail, and examines the sensitivity of a high-resolution numerical model’s explosive cyclogenesis predictions to variations in the treatment of meteorological parameterizations. The effects of model resolution are also illustrated. This storm led to the rapid onset of storm force winds and high seas over eastern Bass Strait and the adjacent Tasman Sea. The storm struck

Full access
Ji-Young Han, Song-You Hong, and Young Cheol Kwon

moist convective-scale downdraft. It employs a bulk mass-flux approach that parameterizes an ensemble of cumulus clouds with different properties as a single bulk entraining/detraining plume in terms of the cloud mass flux under the assumption that it is in quasi-equilibrium with the large-scale forcing. The SAS scheme became an operational CPS in the NCEP Medium-Range Forecast Model in 1993 ( Pan and Wu 1995 ). Since then, many subsequent modifications have been made, for example, to make the

Free access
Yung Y. Chao and Hendrik L. Tolman

optimally uses the higher resolution of the hurricane wind model, suggesting that the spatial resolution of the hurricane wave model needs to be increased to be comparable to that of the hurricane wind model. Note that, generally, better validation of hurricane wave models is greatly hampered by the lack of wave observations with suitable spatial coverage. The NAH and WNA, as is the case with many other existing third-generation (3G) models, are essentially developed and validated on extratropical wind-forcing

Full access
Patrick S. Market, Ronald W. Przybylinski, and Scott M. Rochette

depression of 17°C. Yet, sublimation does permit greater cooling, and it will be accounted for as needed. This paper will demonstrate the importance of both frontogenesis in forcing ascent with this event and the dry lower-tropospheric air for allowing sublimation of snow and the creation of a subfreezing layer all the way to the surface in a late-season event; it is the latter issue that led to widespread error in the forecasting community with this event. Section 2 provides a brief synoptic overview

Full access
Bing Fu, Tim Li, Melinda S. Peng, and Fuzhong Weng

and Chang (1988) . All three of the precyclogenesis disturbances discussed are most prominent in low-level atmospheric circulations. Thus, one may take advantage of Quick Scatterometer (QuikSCAT) satellite products to explore their structures and the characteristics of their evolutions prior to tropical cyclogenesis. In addition, other satellite products and reanalysis fields will also be used to examine convection and other possible upper-tropospheric forcings. This paper is organized as follows

Full access
Robert R. Hoffman

workstation environment to support theactivities ofoperational forecasters and research meteorologists. AMP system research and development projectsare underway at laboratories of the National Weather Service, the U.S. Air Force, and a number of universitiesand private corporations. AMP systems will integrate artificial intelligence techniques with forecasting procedures,and will support the interpretation and integration ofdata from new remote sensing satellites and new groundbased radars. This article

Full access