Unit 4 Weather about Doppler Radar

weather basics the uneven heating of the Earth’s surface Where does the energy for weather originate? the uneven heating of the Earth’s surface

Heat Transfer in 3 ways:

In the US, the general direction that weather systems weather basics In the US, the general direction that weather systems move is toward the North and East FROM the SW

RUNOFF INFILTRATION PRECIPITATION CONDENSATION EVAPORATION ABSORPTION TRANSPIRATION RUNOFF ABSORPTION INFILTRATION

dewpoint are measured in Station Models Please go to page 13 of the ESRTs Temperature and dewpoint are measured in degrees _______ 0F

.. 76 138 -30\ 55 Cloud Cover Temperature Wind Direction & Speed Present Weather 55 Dewpoint Barometric Trend Barometric Pressure

Barometric Pressure 138 ADD a 9 if the number is above “500” or a 10 if the number is below “500” in front to fit on the scale (ranges from 950.0 to 1050.0) 10138 Add a decimal between the last two digits 1013.8 mb

Trend (last 3 hours) The decimal has been omitted (left out) 30 = 3.0 + means rising - means falling

Present weather is light rain Station models info. Temp Dew cloud Press (mb) Trend Wind Speed 760 F 550 F 100% 1013.8 Falling 3.0 mb NE 15 knots Present weather is light rain

Station Model Practice Wkst 1 and 2

MOISTURE page 5

Evaporation Rates a- Temperature c- Relative Humidity b- Surface Area

as temperature increases, the rate of evaporation Direct Relationship as temperature increases, the rate of evaporation increases

as surface area increases, the rate of evaporation Direct Relationship as surface area increases, the rate of evaporation increases

as the air becomes more saturated, the rate of evaporation Relative Humidity The % of moisture in the air Inverse Relationship as the air becomes more saturated, the rate of evaporation decreases

What natural process cleans the atmosphere? Rain precipitation Snow Hail

Cloud Formation

dewpoint = condensation Cools to the dewpoint = condensation Expands & cools Warm Air Rises

Clouds are likely to form when: The air is SATURATED and RISING The temperature is at the DEWPOINT Condensation NUCLEI are available

As air temperature increases the air can "hold" more water

lower due to evaporation Sling Psychrometer Dry bulb measures air temperature Wet bulb temp is lower due to evaporation

Using the charts on page 12 of the ESRTs, calculate the relative humidity and dew point using the following information. Dry Bulb Wet Bulb Difference Dew Point Relative Humidity (%) 14 10 4 20 5 30 19 18 56 6 60 15 12 58 23 7 55 13 5 9 Dewpoint Chart RH Chart

Relative Humidity vs Air Temperature Inverse Relationship as temp. decreases RH increases

As dew point increases, the amount of moisture in the air

dewpoint get closer together, the probability of precipitation As temperature and dewpoint get closer together, the probability of precipitation INCREASES

Circle the precip. probability

probability of precipitation? Which has the greatest probability of precipitation?