DEPARTMENT OF GEOSCIENCES                                                                Spring 2009

San Francisco State University                                      NAME________________________

 

Synoptic Metr Quiz #2

100 pts.

(Test will be collected at 10:40 AM)

 

1.    Definitions.  Choose two of the terms below.  Provide a one sentence definition (if the term is an abbreviation, first “unabbreviate” it and then define it).  (5 pts each for a total of 10 pts).

 

(a) CAPE

 

 

(b) Equilibrium Level

 

 

 

(e) Lifted Index

 

 

 

(d) Convective Temperature

 

 

 

2.  Units.  Provide the units (metric) used conventionally for the following (8 pts)

        

         horizontal winds    meters per sec or m s-1 (or km h-1)    

 

        

         pressure gradient            __________________________________

 

         lifted index                     __________________________________

 

         CAPE                                    __________________________________

 

         CIN                              __________________________________

 

 

 

 

 


 

Map Questions  (82 pts) (Use back of sheets if necessary.  Answer in complete sentences.  )

3.       The sounding for Fort Worth, TX (KFWD) for 0000 UTC 4 May 1999 is shown in Fig 1.  (30 pts total)

 

(a)           Determine the elevation (mb)  of the LCL, LFC, and EL and the value of LI for the sounding. (Show the ascent curve, and make sure to plot the positions of the levels on the ascent curve) (28 pts)

(b)           Shade in the portion of the modified sounding that has positive buoyancy (CAPE) in red. (2 pts)

 

 

4.       The sealevel pressure map for 2200 3 May 1999 is given as Fig. 2.  Note the lines indicated as Lines A, B and C.  The area experiencing dew point temperatures exceeding 60oF is shaded green.(22 pts total)

    (a)  Identify (4 pts each for 12 pts here):

 

Line A _____________________

 

Line B _____________________

 

Line C _____________________

 

(b)  The low pressure area shown on the chart is known as a “wave cyclone”.  Why is the low a “cyclone”? (5 pts here)

 

 

 

 

 

 

 

 

(c)  The low pressure area shown on the chart is known as a “wave cyclone”.  What does the adjective “wave” refer to in this term?  (5 pts here)

 

 

 

 

 

 

 

 

5.       The CAPE/CIN field for 2200 UTC 3 May 1999 is given in Fig. 3.  Compare the pattern shown with the dew point field depicted in Fig. 2.

        

(a)  Briefly explain why the CAPE field is consistent with the dew point field (15 pts);

 

 

 

 

 

 

 

 

 

(b)  Describe why the fact that thunderstorms were erupting over a broad area of southern Kansas, Oklahoma and north Texas would be expected given the information depicted in both Figs. 1 and 3.  (Careful, it’s not just that CAPE is present) (15 pts)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



 

 

 

Figure 1:  KFWD Sounding, 0000 UTC 4 May 1999

 

Figure 2: Sealevel pressure map, 2200 UTC 3 May 1999.  Boundaries are indicated as Lines 1, 2 and 3, and area of surface dew point exceeding 60oF is shaded in green.

 

 

Figure 3:  Distribution of CAPE (red) and CIN (blue), 2200 UTC 3 May 1999.