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No winner this week. Here is my weekly weather quiz question for the last time. There are six different kinds of radar images. What are they? (Name as many as you can.)

There are six different types of images currently available for the RIDGE radar display: Base Reflectivity, Composite Reflectivity, Base Velocity, Storm Relative Motion, One-hour Precipitation and Storm Total Precipitation.

Base Reflectivity

This is a display of echo intensity (reflectivity) measured in dBZ (decibels of Z, where Z represents the energy reflected back to the radar). “Reflectivity” is the amount of transmitted power returned to the radar receiver. Base Reflectivity images are available at several different elevation angles (tilts) of the antenna and are used to detect precipitation, evaluate storm structure, locate atmospheric boundaries and determine hail potential.The base reflectivity image is from the lowest “tilt” angle (0.5°). This means the radar’s antenna is tilted 0.5° above the horizon. Learn more about Base Reflectivity.

Composite Reflectivity

This display is of maximum echo intensity (reflectivity) from any elevation angle at every range from the radar. This product is used to reveal the highest reflectivity in all echoes. When compared with Base Reflectivity, the Composite Reflectivity can reveal important storm structure features and intensity trends of storms. Learn more about composite reflectivity.

Base Velocity

This display of radial velocity represents the overall wind field. Green colors indicate wind moving toward the radar with red colors indicating wind moving away from the radar. The maximum range of this product is 124 nm (about 143 miles) from the radar location. Learn more about Base Velocity images.

Storm Relative Motion

This display is of radial velocity of the wind relative to the storm’s motion. The result is a picture of the wind as if the storms were stationary. This often unmasks storms that rotate (supercells) which can be a precursor to the formation of tornadoes. Green colors indicate wind moving toward the radar with red colors indicating wind moving away from the radar. The maximum range of this product is 124 nm (about 143 miles) from the radar location. Learn more about Storm Relative Motion images.

One-hour Precipitation

This is an image of estimated one-hour precipitation accumulation. This product is used to assess rainfall intensities for flash flood warnings, urban flood statements and special weather statements. The maximum range of this product is 124 nm (about 143 miles) from the radar location. This image will not display accumulated precipitation more distant than 124 nm, even though precipitation may be occurring at greater distances. To determine accumulated precipitation at greater distances you should link to an adjacent radar. Learn more about the one-hour precipitation image.

Storm Total Precipitation

This image is of estimated accumulated rainfall, continuously updated, since the last one-hour break in precipitation. This image is used to locate flood potential over urban or rural areas, estimate total basin runoff and provide rainfall accumulations for the duration of the event.The maximum range of this product is 124 nm (about 143 miles) from the radar location. This product will not display accumulated precipitation more distant than 124 nm, even though precipitation may be occurring at greater distances. To determine accumulated precipitation at greater distances link to an adjacent radar.

I’ll have a new weekly weather quiz question for you Monday. Please remember to post your answer as a comment by clicking on “no comments /comments” in the upper right hand portion of this page under the caption, then add your comment. The first person to post the correct answer will win a week of free personalized weather forecasts tailored to your needs. The answer has to be a comment to win. An email answer will not count.

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Advisories: A FREEZE WATCH IS IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR THE KLAMATH BASIN, NORTHERN AND EASTERN KLAMATH COUNTY, WESTERN, CENTRAL, AND EASTERN LAKE COUNTY.

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An upper level trough of low pressure (“U” shape in blue arrows and shaded) is moving through the Pacific Northwest and will, with the help of a cold front , bring a chance of us getting wet tonight and Monday. A high pressure ridge (“Arch shape shaded grey and with blue arrows ” will bring back the sunshine and warm us up a bit.

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Forecast for the Umpqua Basin including Roseburg: Partly cloudy this evening, cloudy with patchy fog and a slight (20%) chance of showers tonight, mostly cloudy with patchy fog and a slight (20%) chance of rain Monday AM, a slight (20%) chance of showers in the afternoon, partly cloudy in the evening, mostly clear by late Monday night, sunny Tuesday and Wednesday with clear skies at night lows 52-44 warming to 52 Wednesday night highs 74-85. Sunny Thursday and Friday with clear nights, mostly clear Friday night, then mostly sunny Saturday and Sunday with mostly clear nights highs 92-80 lows 52-48. (seasonal averages high 81 low 53)

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Forecast for the South Oregon Coast including Coos Bay and North Bend: Mostly cloudy with patchy coastal fog and a slight (20%) chance of showers tonight, mostly cloudy with patchy AM fog and a slight (20%) chance of rain, a slight (20%) chance of showers Monday afternoon, mostly cloudy in the evening, partly cloudy Monday night and Tuesday AM, sunny in the afternoon, mostly clear inland Tuesday night, mostly clear in the evening and partly cloudy late Tuesday night at the shore  lows 52-45 warming to 48 Wednesday night highs 64-60 warming to 65 Wednesday. Mostly sunny Thursday through Saturday with clear nights, then partly cloudy Saturday night and Sunday highs 62-60 warming to 63 Sunday lows near 48. (seasonal averages high 65 low 51).

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Forecast for the Cascades of Lane County: Partly cloudy this evening, mostly cloudy late tonight, cloudy and cooler with a good (50%) chance of showers Monday AM, a slight (20%) chance of showers in the afternoon, partly cloudy and colder Monday night, a mix of clouds and sun and warmer Tuesday, clear Tuesday night, sunny Wednesday, then clear Wednesday night free air freezing level 13,000 ft. tonight, snow level above 8,000 ft. Monday, free air freezing level 13,000 ft. Monday night, 12,000 ft. rising to 13,000 ft. Tuesday afternoon, then 14,000 ft. Wednesday and Wednesday night lows 39-35 rising to 42 Wednesday highs 52-75. Sunny and warmer Thursday and mostly clear at night, mostly sunny Friday through Sunday with mostly clear skies at night free air freezing level 13,000 ft. Wednesday, then 14,000 ft. Wednesday night through Sunday highs 79-68 lows 42-48 cooling to near 40 Saturday night.

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**Because weather forecasting is a combination of science, intuition, and timing there can be no absolute guarantees that individual forecasts will be 100% accurate. Nature is in a constant state of flux and sudden unexpected weather events can happen.

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Get your local Eugene-Springfield news on-line at Eugene Daily News.com

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