Computation of Hail Size

 Web www.tpub.com

Home

Information Categories
Aerographer
Automotive
Aviation
Combat
Construction
Diving
Draftsman
Engineering
Electronics
Food and Cooking
Math
Medical
Music
Nuclear Fundamentals
Photography
Religion
USMC

Products
Educational CD-ROM's
Printed Manuals

Back ] Home ] Up ] Next ]

Computation of Hail Size

This method of computing hail size is based on the estimates of updraft and downdraft velocities in thunderstorms and the resulting probabilities of hail produced in a thunderstorm

Figure 6-2-18.-Surface hail prediction diagram.

reaching the surface. This technique is called the Fawbush-Miller Hail Forecast method. The procedure to calculate hail size is as follows:

1. From the temperature curve at –5°C, extend a dry adiabat downward until it intersects the pressure level of  and read the temperature T2 at this intersection. We will call this temperature in our example, figure 6-2-19, view A.

2. Calculate the difference between this temperature (T2) and –5°C. Call this value A. The difference is or simply

Figure 6-2-19.-Surface-hail-size calculation: (A) Calculation example, (B) hail size graph.

3. From the intersection with the temperature curve, draw a saturation adiabat up-ward to intersect the pressure level where the air temperature is –5°C, and read the temperature at this intersection. We will call this temperature T3 in our example.

4. Calculate the difference between this temperature T3 and –5°C. Call this value B. This difference is or simply

5. Enter figure 6-2-19, view B, with values A and B to find the hail size on the Fawbush-Miller Hail Graph.

6. If your WBZ is above 10,500 feet, enter figure 6-2-20 with the hail size from step 5 and your WBZ height to determine a corrected hail size.

Learning Objective: Describe the computa-tion procedure for contrail formation analysis on the Skew T.

Back ] Home ] Up ] Next ]