Department of Earth & Climate Sciences Name San Francisco State University Fall 2018 ERTH 360 Homework #1 Answer Sheet (Graphics Online) 100 points (Due Beginning of Class, Thursday 20 September 2018) Note: When written answers are required, please respond with a complete sentence or sentences, each with a subject, verb and object. You may respond on this sheet or on back. You do not need to print the graphics, though you will need to look at them. 1. Examine the chart below, which shows the climate normals for San Francisco Downtown. Answer the questions below the chart in the space provided or on separate sheet. (11 points each for a total of 22 points) a. A major theme in this class is that what the public perceives as an unusual event must be evaluated against what expectations one might have that that event is typical or atypical in a given climate. Using the information given in the chart above, describe why a monthly rainfall total of 1.35" recorded at the Downtown San Francisco rain gage would be extremely unusual in July, but not so in December. (11 pts)
b. Another major theme in this class will be the impact of increasing global temperatures on California weather patterns. Current projections are that through the early part of the 21st century, average annual precipitation in this part of California should increase slightly. The normal annual rainfall for the Downtown San Francisco rain gage is currently 23.73:, as discussed in class. Using this link, http://wrcc.dri.edu/cgi-bin/climain.pl?ca7772 determine the normal annual rainfall for the 1971-2000 and 1961-1990 periods. Are these figures consistent or inconsistent with the notion that precipitation should be slightly increasing in this part of California. (11 pts)
2. Examine the visible and infrared satellite images below (1615 UTC 31 Aug 2016) centered over Hurricane Lester. Note the locations lettered A, B and C. These locations are exactly the same on both images and refer to specific cloud areas at those locations on each image. (16 pts total) (a) At which of the three locations is precipitation likely to be the heaviest? (3 pts) Describe how you used the information shown on the two images to answer this question. Answer the question in complete sentences in the space provided or on separate sheet. (5 points) (b) At which of the three locations is the cloud type MOST likely to be cumulonimbus? (3 points) Describe how you used the information shown on the two images to answer this question. Answer the question in complete sentences in the space provided or on separate sheet. (5 points)
3. The figure below is the 6:53 PM EDT (3:53 PM PDT) 1 September 2016 radar image centering on Hurricane Hermine.. On this day, flash flooding was observed in the areas around the Panhandle and northwestern sections of Florida (11 points in this section) (a) Distinguish what a radar chart GENERALLY shows meteorologists from what a satellite image generally shows? Answer the question in the space provided or on separate sheet. (3 points) (b) How does this image indicate to meteorologists that heavy to very heavy precipitation was occurring in portions of the area depicted at the time of the chart? Answer the question in the space provided or on separate sheet. (5 points) (c) 6:53 PM EDT (3:53 PM PDT) 1 September 2016 corresponds to what date and time UTC? (3 points)
4. The chart below is the US Navy past and forecast track chart issued at 06 UTC 11 September 2018 for Hurricane Florence. (11 pts) (a) The hurricane symbols plotted on the chart are linked with either a dotted blue line or a solid blue line. Explain the difference in interpretation of the dotted and solid blue lines. (3 points) (b) What are the maximum sustained wind and gust wind speeds forecast for Florence on 18 UTC September 12, 2018. (4 points) (c) How close to Cape Hatteras, North Carolina was Florence expected ever to get in its life cycle and track? (Answer in miles or nautical miles) (4 points)
5. Examine the weather information given below. Fill in the table with the appropriate information. Be sure to indicate units. (1 point each for a total of 30 points). Please remember that you are DECODING the information. Hence, please include the units (as in 46 0 F) Station Temp Dew Point Temp Brownsville (BRO) Houston (HOU) San Francisco (SFO) Oklahoma City (OKC) St. James (VIH) Pressure Wind Dir Wind Spd Present Weather None None
6. Examine the information ONLY for VIH (St. James) and BRO (Brownsville). (10 points) (a) Which of the two places is experiencing the GREATEST relative humidity? (2 points) How Did You Tell? ( 3 points) (b) Which of the two is experiencing the LEAST amount of water vapor? (2 points) How Did You Tell? (3 points)