. "Appendix A: A Rationale for Choosing the Spatial Density and Temporal Frequency of Observations for Various Atmospheric Phenomena." Observing Weather and Climate from the Ground Up: A Nationwide Network of Networks. Washington, DC: The National Academies Press, 2009.
The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
Observing Weather and Climate from the Ground Up: A Nationwide Network of Networks
A Rationale for Choosing the Spatial Density and Temporal Frequency of Observations for Various Atmospheric Phenomena
The question is perennial: “How many observations do I need, and how dense and how frequent?” The honest answer is “It depends upon the application.” This appendix deals with a single but very important application: observational support of the national infrastructure for weather and climate monitoring and numerical weather prediction. Even for this single application area, the answer to the question depends upon the phenomenon: its size and longevity, which governs its predictability, and whether it has any embedded features that cause localized damage. Consideration of the phenomena is roughly in the order of size/longevity. The list is neither definitive nor exhaustive, but it does cover events that cause the greatest disruption, damage, and loss of life.
FLOODING FROM LARGE-SCALE STORMS
Definition: Steady soaking rains, sometimes with embedded showers and thunderstorms, cause flooding of small streams and larger rivers. Rain falling on melting snow exacerbates the flooding.
Size: Typically 300-2000 km across.
Duration: half a day to several days
Geographic preference: West Coast, Southern Plains, Lower Midwest, Appalachians. Rapid melting of a heavy snow cover, especially when accompanied by rainfall, sometimes causes floods in the northern United States,