Search Results

You are looking at 11 - 17 of 17 items for :

  • Predictability and Dynamics of Weather Systems in the Atlantic-European Sector (PANDOWAE) x
  • Monthly Weather Review x
  • All content x
Clear All
Christian M. Grams and Heather M. Archambault

enhanced poleward moisture transport that occurs often on the eastern side of a transitioning TC. When this moisture impinges on a midlatitude baroclinic zone in a region of upper-level forcing for ascent [e.g., near the equatorward entrance region of an upper-level jet streak; Uccellini and Johnson (1979) ] several days prior to ET, heavy precipitation and flooding may occur as a result of quasi-stationary convection in that region (e.g., Wang et al. 2009 ; Galarneau et al. 2010 ; Byun and Lee

Full access
Hilke S. Lentink, Christian M. Grams, Michael Riemer, and Sarah C. Jones

Research and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T-PARC). Measurements from three aircrafts provide a unique dataset for detailed analysis of structural development during ET. Between 0100 and 0600 UTC 19 September and between 0500 and 0900 UTC 20 September, the research aircrafts Naval Research Laboratory P-3 and the U.S. Air Force WC-130 flew through the central region to obtain measurements of the eyewall. The DLR-Falcon was operating in the environment northeast of

Full access
Volkmar Wirth, Michael Riemer, Edmund K. M. Chang, and Olivia Martius

and E have been created during that time. c. Different types of RWPs and their propagation There are different types of RWPs associated with different temporal and spatial scales, different types of forcing, and specific properties of the background flow. Sometimes an RWP is little more than an individual trough or ridge ( Sanders 1988 ); sometimes an RWP may span a substantial part of the globe ( Branstator 2002 ). Some RWPs propagate along great circles, while others are ducted in the zonal

Open access
Julia H. Keller, Christian M. Grams, Michael Riemer, Heather M. Archambault, Lance Bosart, James D. Doyle, Jenni L. Evans, Thomas J. Galarneau Jr., Kyle Griffin, Patrick A. Harr, Naoko Kitabatake, Ron McTaggart-Cowan, Florian Pantillon, Julian F. Quinting, Carolyn A. Reynolds, Elizabeth A. Ritchie, Ryan D. Torn, and Fuqing Zhang

cyclone constitutes an external forcing with persistent structure to the midlatitude wave. This idea is in marked contrast to traditional initial-value studies of baroclinic development, in which the initial perturbations are embedded in the midlatitude flow and are thus not an external forcing (e.g., Simmons and Hoskins 1979 ; Hakim 2000 ). 2) Evolution of the upstream trough ET may also influence the upstream trough, which may experience modifications of its shape, meridional extension, and

Open access
Gabriel Wolf and Volkmar Wirth

.g., Dritschel and McIntyre 2008 ). A strong gradient of potential vorticity, in turn, represents a strong restoring force for parcels away from its unperturbed trajectory, which guarantees close to linear wave behavior. The jet in this context is considered to be part of the background flow, and to the extent that the jet makes some gentle excursions in the meridional direction, the RWP follows these excursions on its otherwise zonal and eastward trajectory. Anomalies due to the RWPs are measured with

Full access
Julia H. Keller, Sarah C. Jones, and Patrick A. Harr

extratropical cyclone, veering away from Choi-Wan and the inherent generation of K e due to baroclinic processes. In these cases, Choi-Wan has only a minor impact on the amplification of the wave train w a . Furthermore, converging energy fluxes from upstream regions suggest a midlatitude forcing in scenario III. If Choi-Wan merges with the frontal wave (scenario II, Fig. 8b ), wave train w a is strongly amplified, due to the downstream dispersion of K e , emanating from the storm, and propagates

Full access
Marlene Baumgart, Michael Riemer, Volkmar Wirth, Franziska Teubler, and Simon T. K. Lang

-0315.1 Moncrieff , M. W. , D. E. Waliser , and J. Caughey , 2012 : Progress and direction in tropical convection research: YOTC International Science Symposium . Bull. Amer. Meteor. Soc. , 93 , ES65 – ES69 , https://doi.org/10.1175/BAMS-D-11-00253.1 . 10.1175/BAMS-D-11-00253.1 Nie , Y. , Y. Zhang , G. Chen , and X.-Q. Yang , 2016 : Delineating the barotropic and baroclinic mechanisms in the midlatitude eddy-driven jet response to lower-tropospheric thermal forcing . J. Atmos. Sci

Open access