Weather and Forecasting: Recent submissions

Now showing items 1421-1440 of 3043

    • Effective Storm-Relative Helicity and Bulk Shear in Supercell Thunderstorm Environments 

      Thompson, Richard L.; Mead, Corey M.; Edwards, Roger (American Meteorological Society, 2007)
      A sample of 1185 Rapid Update Cycle (RUC) model analysis (0 h) proximity soundings, within 40 km and 30 min of radar-identified discrete storms, was categorized by several storm types: significantly tornadic supercells (F2 ...

    • COAMPS Real-Time Dust Storm Forecasting during Operation Iraqi Freedom 

      Liu, Ming; Westphal, Douglas L.; Walker, Annette L.; Holt, Teddy R.; Richardson, Kim A.; Miller, Steven D. (American Meteorological Society, 2007)
      Dust storms are a significant weather phenomenon in the Iraq region in winter and spring. Real-time dust forecasting using the U.S. Navy?s Coupled Ocean?Atmospheric Mesoscale Prediction System (COAMPS) with an in-line dust ...

    • Scoring Probabilistic Forecasts: The Importance of Being Proper 

      Bröcker, Jochen; Smith, Leonard A. (American Meteorological Society, 2007)
      Questions remain regarding how the skill of operational probabilistic forecasts is most usefully evaluated or compared, even though probability forecasts have been a long-standing aim in meteorological forecasting. This ...

    • Tornadoes with Cold Core 500-mb Lows 

      Davies, Jonathan M. (American Meteorological Society, 2006)
      Tornadoes that occur in close proximity to midlevel closed lows with a core of cold temperatures aloft are not uncommon, particularly in the central United States. Although several informal studies have shown that severe ...

    • Reexamination of Tropical Cyclone Wind–Pressure Relationships 

      Knaff, John A.; Zehr, Raymond M. (American Meteorological Society, 2007)
      Tropical cyclone wind?pressure relationships are reexamined using 15 yr of minimum sea level pressure estimates, numerical analysis fields, and best-track intensities. Minimum sea level pressure is estimated from aircraft ...

    • A Pacific Moisture Conveyor Belt and Its Relationship to a Significant Precipitation Event in the Semiarid Southwestern United States 

      Knippertz, Peter; Martin, Jonathan E. (American Meteorological Society, 2007)
      In this study the term moisture conveyor belt (MCB) is defined as an elongated band of enhanced poleward water vapor fluxes (WVFs) above the PBL that is rooted in the Tropics. This new terminology is illustrated through ...

    • Using Wind Anomalies to Forecast East Coast Winter Storms 

      Stuart, Neil A.; Grumm, Richard H. (American Meteorological Society, 2006)
      Forecasting major winter storms is a critical function for all weather services. Conventional model-derived fields from numerical weather prediction models most frequently utilized by operational forecasters, such as ...

    • A Simple and Flexible Method for Ranking Severe Weather Events 

      Doswell, C. A.; Edwards, R.; Thompson, R. L.; Hart, J. A.; Crosbie, K. C. (American Meteorological Society, 2006)
      The notion of an ?outbreak? of severe weather has been used for decades, but has never been formally defined. There are many different criteria by which outbreaks can be defined based on severe weather occurrence data, and ...

    • Comparing Local Analysis and Prediction System (LAPS) Assimilations with Independent Observations 

      Hiemstra, Christopher A.; Liston, Glen E.; Pielke, Roger A.; Birkenheuer, Daniel L.; Albers, Steven C. (American Meteorological Society, 2006)
      Meteorological forcing data are necessary to drive many of the spatial models used to simulate atmospheric, biological, and hydrological processes. Unfortunately, many domains lack sufficient meteorological data and available ...

    • A Preliminary Survey of Rear-Flank Descending Reflectivity Cores in Supercell Storms 

      Rasmussen, Erik N.; Straka, Jerry M.; Gilmore, Matthew S.; Davies-Jones, Robert (American Meteorological Society, 2006)
      This paper develops a definition of a supercell reflectivity feature called the descending reflectivity core (DRC). This is a reflectivity maximum pendant from the rear side of an echo overhang above a supercell weak-echo ...

    • MM5 Ensemble Mean Forecasts in the Taiwan Area for the 2003 Mei-Yu Season 

      Chien, Fang-Ching; Liu, Yi-Chin; Jou, Ben Jong-Dao (American Meteorological Society, 2006)
      This paper presents an evaluation study of a real-time fifth-generation Pennsylvania State University?NCAR Mesoscale Model (MM5) mesoscale ensemble prediction system in the Taiwan area during the 2003 mei-yu season. The ...

    • A Statistical Procedure to Forecast Warm Season Lightning over Portions of the Florida Peninsula 

      Shafer, Phillip E.; Fuelberg, Henry E. (American Meteorological Society, 2006)
      Sixteen years of cloud-to-ground lightning data from the National Lightning Detection Network and morning radiosonde-derived parameters are used to develop a statistical scheme to provide improved forecast guidance for ...

    • Validation of Polarimetric Hail Detection 

      Heinselman, Pamela L.; Ryzhkov, Alexander V. (American Meteorological Society, 2006)
      This study describes, illustrates, and validates hail detection by a simplified version of the National Severe Storms Laboratory?s fuzzy logic polarimetric hydrometeor classification algorithm (HCA). The HCA uses four radar ...

    • Supercell Tornadogenesis over Complex Terrain: The Great Barrington, Massachusetts, Tornado on 29 May 1995 

      Bosart, Lance F.; Seimon, Anton; LaPenta, Kenneth D.; Dickinson, Michael J. (American Meteorological Society, 2006)
      The process of tornadogenesis in complex terrain environments has received relatively little research attention to date. Here, an analysis is presented of a long-lived supercell that became tornadic over complex terrain ...

    • Synoptic and Mesoscale Analysis of a High-Latitude Derecho–Severe Thunderstorm Outbreak in Finland on 5 July 2002 

      Punkka, Ari-Juhani; Teittinen, Jenni; Johns, Robert H. (American Meteorological Society, 2006)
      On 5 July 2002, a rapidly propagating bow echo formed over eastern Finland causing severe wind damage in an exceptionally large area. The Ministry of the Interior?s Emergency Response Centers received nearly 400 ...

    • Objective Estimation of Tropical Cyclone Wind Structure from Infrared Satellite Data 

      Mueller, Kimberly J.; DeMaria, Mark; Knaff, John; Kossin, James P.; Vonder Haar, Thomas H. (American Meteorological Society, 2006)
      Geostationary infrared (IR) satellite data are used to provide estimates of the symmetric and total low-level wind fields in tropical cyclones, constructed from estimations of an azimuthally averaged radius of maximum wind ...

    • A Dynamic Decision Model Applied to Hurricane Landfall 

      Regnier, Eva; Harr, Patrick A. (American Meteorological Society, 2006)
      The decision to prepare for an oncoming hurricane is typically framed as a static cost:loss problem, based on a strike-probability forecast. The value of waiting for updated forecasts is therefore neglected. In this paper, ...

    • A Preliminary Study of Severe Wind-Producing MCSs in Environments of Limited Moisture 

      Corfidi, Stephen F.; Corfidi, Sarah J.; Imy, David A.; Logan, Allen L. (American Meteorological Society, 2006)
      An examination of severe wind-producing mesoscale convective systems that occur in environments of very limited moisture is presented. Such systems, herein referred to as low-dewpoint derechos (LDDs), are difficult to ...

    • Cluster Analysis for Verification of Precipitation Fields 

      Marzban, Caren; Sandgathe, Scott (American Meteorological Society, 2006)
      A statistical method referred to as cluster analysis is employed to identify features in forecast and observation fields. These features qualify as natural candidates for events or objects in terms of which verification ...

    • An Observational Examination of Long-Lived Supercells. Part I: Characteristics, Evolution, and Demise 

      Bunkers, Matthew J.; Hjelmfelt, Mark R.; Smith, Paul L. (American Meteorological Society, 2006)
      Observations of supercells and their longevity across the central and eastern United States are examined, with the primary focus on understanding the properties of long-lived supercells (defined as supercells lasting ≥4 ...