Metr 302 Spring 2004 Homework 1

Department of Geosciences
Name _______________________________

San Francisco State University
Spring 2004

Meteorology 302

Homework #1 Solution

(Section 1: Due Beginning of Class, Friday 20 February 2004)
(Section 4: Due Beginning of Class, Thursday 19 February 2004)

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.

Attached find the following for 2000Z 15 Feb 2001:

(a) Plot of surface weather data for southern Great Plains;

and on class website (approximately 2000 UTC)

(b) Convective Outlook Day 1, IR Satellite Image, Visible Satellite Image, centering on southern Great Plains

1. Examine (a), the plot of surface weather data. Note the weather stations indicated by their three letter designators. Fill in the following table (24 points).

Station	Temp	Dew Point Temp	Pressure	Wind Dir	Wind Spd	Present Weather
Brownsville (BRO)	82F	70F	1008.2 mb	SE	25 mph	None Observed
Houston (HOU)	75F	66F	1009.4 mb	SE	15 mph	None Observed
Dallas (DFW)	39F	39F	1013.4 mb	NW	10 mph	Heavy continuous rain
Oklahoma City (OKC)	28F	27F	1017.0 mb	N	15 mph	Haze
St. James (VIH)	32F	32F	1015.7 mb	Calm	Calm	Moderate fog

2. Examine the Convective Outlook. In one or two sentences, describe what it is showing in the southern Great Plains. (15 pts)

The convective out look indicates that general thunderstorms will be over portions of southern new Mexico, the southern two thirds of Texas, Arkansas and portions of Kentuckey, Tennesee, Mississippi and Louisanna. Within that area of general thunderstorms, there is a portion of south-central and eastern Texas and the western half of Louisanna within which a few of the thunderstorms are likely to be severe.

3. Examine the information for VIH and BRO.

(a) Which of the two places is experiencing the highest relative humidity? (8 pts)

St James (VIH) is experiencing the highest relative humidity, in this case, 100%

How Did You Tell (5 pts)? There is no difference between the temperature and dew point temperature at St. James, while there is a 12 degree difference at Brownsville.

(b) Which of the two is experiencing the greatest amount of water vapor? (8 pts)

Brownsville is experiencing the greatest amount of water vapor.

How Did You Tell? (5 pts) The dew point temperature at Brownsville is 38F higher than that at St. James.

4. Examine the visible and infrared satellite images.

Explain the differences in the two images over the state of Texas. (15 pts)
The visible image shows cloudiness covering almost all of the eastern 3/4 of Texas and Oklahoma. However, the infrared image shows that the coldest tops extended in a much narrower area from southwestern Texas across Oklahoma. These cold tops represent our first guess as to what proportion of the clouds shown on the visible image might be associated with precipitation.
Explain how the two images are consistent with the information indicated on the surface chart. (15 pts)
The surface chart shows that although most stations are cloudy at the time of observation (consistent with the surface chart) only a few of the stations were reporting precipitation, and these seem to correspond to the areas of coldest cloud tops on the infrared image.

5. What is the date and time of the surface chart in:

(a) Pacific Standard Time? (2 pts)

1200 PST (Noon PST) 15 February 2001

(b) Central Standard Time? (2 pts)

1400 CST (2 PM CST) 15 February 2001

Department of Geosciences	Name _______________________________
San Francisco State University	Spring 2004