______________

An upper level low pressure trough (the  “U” shaped dip in the yellow jet stream line) is moving in behind the high pressure ridge (“Arch” shape) that heated us up.  The trough combined with some cool Canadian air will return our temperatures back to the 80s. A weak cold front should drop down and push through the Pacific Northwest Wednesday keeping our temperatures pretty steady.

_______________

Advisories:   A HEAT ADVISORY IS IN EFFECT UNTIL 9 PM  TONIGHT FOR THE I-5 CORRIDOR FROM PORTLAND THROUGH EUGENE AND FOR THE CASCADES FOOTHILLS OF LANE COUNTY, AND THE WESTERN COLUMBIA RIVER GORGE.

________________

The updated Pollen Count Forecast for the Eugene-Springfield area : Trees LOW, Grass HIGH, and weeds LOW. (as of 7/22/10) Data from Allergy and Asthma Research Group.

__________________

Here are your detailed forecasts. **

_________________

Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis: Clear tonight, mostly sunny and a bit cooler Monday, mostly clear at night with some patchy low clouds late lows 56-50 high 89. A mix of clouds and sun and cooler Tuesday and Wednesday, partly cloudy Tuesday night and Wednesday evening then mostly cloudy Wednesday night and Thursday AM, and partly cloudy at night highs 85-81 lows 53-50. A mix of clouds and sun Friday through Sunday, and partly cloudy each night highs 82-84 lows near 50. (seasonal averages high 83 low 51)

_________________

Forecast for the Umpqua Basin including, Roseburg:  Mostly clear this evening, partly cloudy tonight and Monday with a slight (20%) chance of isolated afternoon and evening thunderstorms lows 62-60 high 87. Partly cloudy Tuesday through Sunday, mostly clear to partly cloudy skies at night highs 85-88  lows 59-55. (seasonal averages high 87 low 55)

_________________

Forecast for the South Oregon Coast including Coos Bay and North Bend: Partly cloudy  this evening and mostly cloudy at night, and Monday AM, then partly cloudy Monday afternoon and evening, and mostly cloudy Monday night and Tuesday lows 55-50 highs 62-65. Mostly cloudy Tuesday evening, and partly cloudy Tuesday night and Wednesday low 54 high 64. Mostly cloudy Wednesday night and Thursday, then partly cloudy Thursday night through Sunday lows near 50 highs near 63. (seasonal averages high 67 low 53).

_________________

Forecast for the Cascades of Lane County:  Clear tonight, a mix of clouds and sun Monday with a slight (40%) chance of scattered  afternoon and evening thunderstorms, partly cloudy Monday night free air freezing level 15,000 ft. lows near 50 high 82. A mix of clouds and sun Tuesday and Wednesday  with a (30%) chance of afternoon and evening thunderstorms, mostly sunny  Thursday AM then partly cloudy with  a slight (20%) chance of afternoon thunderstorms, and mostly clear Thursday night night free air freezing level 14,000 ft. falling to 13,000 ft. Wednesday night through Thursday night highs 78-73 lows near 48-44. Mostly sunny Friday through Sunday, and mostly clear each night free air freezing level 13,000 ft. then rising to 14,000 ft. Saturday highs 76-78 lows 45.

_________________

**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.