پاورپوینت Snow to Liquid Ratio Climatology and Forecast Methodologies

پاورپوینت Snow to Liquid Ratio Climatology and Forecast Methodologies

پاورپوینت Snow to Liquid Ratio Climatology and Forecast Methodologies

 

 

 

 

 

 

 

نوع فایل power point

 

قابل ویرایش 49 اسلاید

 

قسمتی از اسلایدها

Forecasting Winter Precipitation is a Two-Step Process

First, the current dynamic and thermodynamic forcings of the storm must be assessed.

Numerical model forecasts must be studied, especially the model quantitative precipitation forecast (QPF).

Second, the evolution of the hydrometeors from their origin to the surface must be predicted.

This evolution will be determined by the vertical profile of temperature and moisture.

This profile will elucidate the type of precipitation- rain, snow, freezing rain, ice pellets, or any combination.

If the precipitation is expected to fall as snow, a snow to liquid equivalent ratio must be determined to forecast the actual snow amount.

Why is liquid ratio important to forecasters?

After forecasting liquid equivalent (QPF), the snow-liquid equivalent ratio must be estimated.

Significant variations in snow to liquid equivalent ratio can occur even within a single storm system

A more clear understanding of the processes that act to vary snow density will enable the forecaster to employ a more scientific process oriented method toward forecasting snowfall, versus commonly used empirical techniques.

 A challenge exists to determine the extent of interaction between the dynamical forcing and the microphysical processes that determine snow density (i.e., how efficient is the forcing in producing snowfall from a given amount of liquid equivalent?).

SLR determines the wintertime precipitation efficiency

 

فهرست مطالب و اسلایدها

Forecasting Winter Precipitation is a Two-Step Process

Why is liquid ratio important to forecasters?

Description of Dataset and Methods

Station distribution of the 30 year climatology

Histogram for the Entire Dataset of SLR

Sample SLR Climatological Distributions

Variability of Mean SLR within LSX

Ratio typically varies with storm track

Ice Crystal Habits

Crystal habit depends on temperature and degree of saturation

Ice Crystal Riming

Billings, MT ACARS Sounding

A Physically-Based Method Using Climatology

Why must we use Climatology?

How do I find the 850 mb Temp Anomalies?

Other Methods for Forecasting SLR – Neural Network

Most Important Factors in Forecasting SLR

Verification of the Roebber Algorithm

Other Methods for Forecasting SLR – Cobb Method

The Cobb Method

The Cobb Method – Sample Calculation

Verification of the Cobb Method

One More Method – Dube Method (MSC)

Sample Case - Roebber Method

Verification – 24 hr Snowfall Totals

Snow to Liquid Ratio Overview