LONG RANGE FORECAST THROUGH THE END OF APRIL - 4/21/2018
April is the first full month of spring. April typically is when we see the heavy rains and snows of the wet season wind down. Early April in Southern Oregon can be still be very chilly to even cold. The Pear Blossom Festival during the second weekend of April in Medford is usually plagued with colder temps and showers if not rain. Snow can still fall to low elevations. Typically April will have highs in the 60s and 70s at the beginning of the month which becomes mostly 70s with some 80s by the end of the month for highs. Overnight lows can be quite chilly through mid month. Most locations in the region will still have the risk of frosts. April on average is typically going to give us about one and a third inches of rain in Medford. April will generate about 2 -3 inches of rain along the Coast in a normal year. Snow levels in the mountains usually are going up, but snowfalls up to 3 feet above 4500 feet have occurred in April.
April so far has been dominated by colder than normal conditions. It has also see above average rain and snow for Northern California. In Southern Oregon we have been much drier. But, we are now seeing a dramatic pattern shift that is going to stay from all indications of the model and data. We are going to be seeing warmer then normal temps with drier than averavge conditions. That looks to persist into the middle of May for sure at this time. This means that highs will be mostly in the 70s and 80s for the valleys west of the Cascades, with 60s and 70s for areas east of the Cascades. In the mountains warmer than normal temps are going to lead to snowmelt commencing and then sustaining. What snowpack we do have looks to deplete quickly with conditions as they are expected to be. Overnight temps will support frosts for sure and likely freezing conditions east of the Cascades and down in interior Northern California. The valleys of Southwestern Oregon are more likely to see frost in outlying areas. Not seeing anything that looks like it will be causing wide spread freezes west of the Cascades.
Rain looks as though it will be very spotty and due to shower and thunderstorm activity now. That is typical for this time of the year here. I do not see big well organized winter type storms with sustained rains and mountain snow hitting anywhere in our area now. That activity will be well to our north as the storm track has shifted that way. April in Medford typically will see about 1.40 inches for rainfall. It is possible we can hit that mark or go higher before the end of the month with what potential we do have. But, as is the nature with showers and thunderstorms....going to need direct hits of heavier showers and storms to get us there. The current models and data have snow levels very high in the mountains now. It looks like Crater Lake National Park has the best chance to see more snow of any single location in our area that people frequent. It does not look like there will be any real addition to the snow pack even there. So, expect the snow melt off to occur there at a vigorous rate now due to the temperature change.