Pre-Lab: Building a Streamline Analysis » Basic Approach and Tips

Here are some general guidelines to keep in mind during the streamlining process. Refer to these guidelines when attempting the practice exercises on the next page and during lab.

• Draw streamlines freehand, keeping them parallel to the overall flow
• Streamlines never cross, except at a neutral point
• Draw streamlines at a roughly regular interval, keeping them frequent enough for another user to easily gauge the overall flow in all regions
• Where winds are slow, it may be difficult or impossible to match all observed wind directions
• A neutral point must exist between two like systems (e.g., two anticyclones), large regimes of opposing flow, and where flow within an indraft or outdraft meets the opposing background flow
• A starting point for drawing streamlines is based on the analyst's judgment. It is commonly easiest to begin with centers of circulation, flow transitions (neutral points), and main flow lines
• When beginning any streamline analysis, first look for the overall flow pattern and main features - this is akin to examining the entire area of the map for maxima, minima and troughs before drawing the first isobar when contouring pressure
• Situational awareness: it is most instructive to examine previous streamline analysis from recent hours. Additionally, satellite and radar loops, where available, can help fill in gaps where observations are sparse.
• And last, but not least: for hand analysis, USE A PENCIL FOR INITIAL SKETCHING!