Here is my weekly weather quiz question. “What is the “Showalter Index?”
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An Upper Level Low is moving away from us but still producing sunshine with high temperatures in the 90s. The graphics for days 1-3 show a frontal system sliding into Oregon Friday. The graphics for days 3-7 Sunday through Thursday show a cold frontal system approaching from the west Sunday, then the cold front slides into the Pacific Northwest between Monday and Tuesday.
ADVISORIES:
- AN EXCESSIVE HEAT WATCH IS IN EFFECT FROM SATURDAY AFTERNOON THROUGH TUESDAY EVENING FOR THE OREGON LOWER TREASURE VALLEY.
- AN EXCESSIVE HEAT WARNING IS IN EFFECT UNTIL NOON MDT SATURDAY FOR THE OREGON LOWER TREASURE VALLEY.
- A HEAT ADVISORY IS IN EFFECT UNTIL 10 PM TONIGHT FOR THE LOWER COLUMBIA BASIN OF OREGON.
- AN EXCESSIVE HEAT WATCH IS IN EFFECT FROM SATURDAY AFTERNOON THROUGH TUESDAY EVENING FOR MALHEUR COUNTY.
- AN EXCESSIVE HEAT WATCH IS IN EFFECT FROM SATURDAY MORNING THROUGH TUESDAY EVENING FOR BAKER COUNTY.
- AN AIR QUALITY ADVISORY IS IN EFFECT UNTIL 2 PM FRIDAY FOR HARNEY AND MALHEUR COUNTIES.
HEALTH ADVISORIES:
- A PERMANENT HEALTH ADVISORY REMAINS IN EFFECT FOR THE SOUTH UMPQUA RIVER BAR. POOLS IN THE BEDROCK ALONG THE RIVERS EDGE ARE KNOWN TO DEVELOP BLUE-GREEN ALGAE (CYANOBACTERIAL) BLOOMS THAT CAN BE HARMFUL TO PETS AND PEOPLE IF ACCIDENTAL INGESTION OCCURS. SIGNS HAVE BEEN POSTED ALONG SEVERAL ACCESS AREAS ALONG THE RIVER.
Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis:
- Mostly clear with patchy fog tonight,
- Patchy AM fog, sunny and a bit warmer Friday, clear Friday night,
- Sunny and a bit warmer Saturday, mostly clear in the evening, partly cloudy late at night,
- Mostly sunny and a bit cooler Sunday, then mostly clear Sunday night.
- lows 52-58 cooling to 54 Sunday night highs 92-95 cooling to 86 Sunday.
- Mostly sunny and a bit cooler Monday, mostly clear Monday night,
- Then sunny and a bit warmer Tuesday, Wednesday, and Thursday, clear at night,
- highs 85-89 lows near 50 (seasonal averages high 85 low 52)
Forecast for the Umpqua Valley including Roseburg:
- Mostly clear with patchy fog late tonight,
- Areas of AM clouds with patchy fog, sunny and a bit cooler Friday afternoon, clear with patchy fog late Friday night,
- Patchy AM fog, sunny Saturday afternoon, partly cloudy with a slight (20%) chance of evening thunderstorms, mostly cloudy with a slight (20%) chance of thunderstorms late at night,
- Mostly cloudy with patchy AM fog and a slight (20%) chance of thunderstorms, partly cloudy and a bit cooler Sunday afternoon, mostly clear in the evening, then partly cloudy Sunday night.
- lows 56-62 cooling to 58 Sunday night highs 93-84.
- Some AM clouds, sunny and a bit warmer Monday afternoon, mostly clear Monday night,
- Mostly sunny and a bit warmer Tuesday, clear at night,
- Sunny Wednesday, clear Wednesday night,
- Then sunny and a bit warmer Thursday.
- highs 86-88 lows 54-56 (seasonal averages high 87 low 58)
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Forecast for The South Oregon Coast Including Coos Bay and North Bend:
- Mostly clear with patchy evening coastal fog and partly cloudy with areas of coastal fog late tonight while mostly clear with patchy evening inland fog and partly clear partly cloudy with patchy inland fog late tonight,
- Patchy AM fog, sunny Friday afternoon, clear with patchy evening coastal fog and mostly cloudy with patchy coastal fog late at night while becoming mostly cloudy with patchy inland fog late Friday night,
- AM clouds with patchy fog, sunny and a bit warmer Saturday afternoon, mostly cloudy with a slight (20%) chance of thunderstorms at night and patchy coastal fog late at night,
- Mostly cloudy with patchy fog and a slight (20%) chance of AM thunderstorms, just mostly cloudy and a bit cooler Sunday afternoon, mostly cloudy Sunday night.
- lows 56-54 highs 67-72 cooling to 69 Sunday.
- Mostly cloudy start, sunny and a bit warmer Monday, mostly clear Monday night,
- Mostly sunny and a bit warmer Tuesday, mostly clear at night,
- Sunny Wednesday, mostly clear at night,
- Then mostly sunny Thursday.
- highs 70-72 lows near 50. (seasonal average high 66 low 54)
Forecast for the Northern Oregon Cascades including the Cascades in Lane County:
- Clear tonight,
- Sunny and a bit warmer Friday, clear Friday night,
- Sunny and a bit warmer Saturday, mostly clear in the evening, partly cloudy late at night,
- Sunny and a bit cooler Sunday, then mostly clear Sunday night.
- free air freezing level 15,000 ft. tonight, 15,000 ft. rising to 16,000 ft. Friday afternoon, above 16,000 ft. Saturday and Saturday night, then 16,000 ft. Sunday and Sunday night.
- lows 49-56 cooling to 52 Sunday night highs 80-92 cooling to 83 Sunday.
- Sunny and a bit cooler Monday, mostly clear Monday night,
- Sunny and a bit cooler Tuesday, clear at night,
- Sunny Wednesday, clear Wednesday night,
- Then sunny and a bit cooler Thursday.
- free air freezing level 16,000 ft. Monday, above 16,000 ft. Monday night, 16,000 ft. Tuesday , above 16,000 ft. Tuesday night through Wednesday night, then 16,000 ft. Thursday.
- highs 79-77 lows 45-47.