82 Degrees Monday: Warmest This Year

April 27, 2015

Quite an April “scorcher” out there today:

PLOT_Highs_Metro

The 82 degree high at PDX was above our forecast of 80 degrees.  Not quite a record (86 in 1987), but 18 degrees above average!  The Salem sounding at 5pm showed an 850mb temp of +14.6 degrees.  In non-meteorological jargon: The temperature around 5,000′ elevation over Salem was about 58 degrees.  It could have been even warmer;  my chart for April shows easterly flow, solid sunshine, and a +14 has seen a Portland high temp as high as 85!  Models had shown +12 or +13, thus the forecast of 80.

Maybe more amazing is the jump from yesterday.  The high temp jumped 21 degrees in one day, which I haven’t seen happen in the spring.  Of course we’ve seen it drop 20 degrees in one day (tomorrow?) due to a major marine push and/or a cold front passage.

The easterly pressure gradient has increased this afternoon and evening, giving a peak gust over 50 mph at Crown Point and 40 mph at Corbett.  It’ll back off dramatically by sunrise as low marine clouds flood into the valley.

We’ve got a weak cold front moving inland tomorrow so expect some showers but not a big soaking.  In fact I don’t see any other decent chance for rain in the next 7-8 days.  This might be a year in which we start watering in May unless a trough materializes the middle of next week with a nice soaking (.50″ or more).  Both the 18z GFS meteogram and 12z ECMWF meteogram showed less than 1/2″ in the next 7-10 days.

ecm_meteo

gfs_meteo

It does looks like a very mild and “settled” weather pattern over the next week.  By that I mean that after tomorrow’s disturbance moves past we see the action lift north.  This is typically what we see later in May and June.  So temperatures warm to above average over the next week.  This may be a re-emergence of the ridging we’ve seen so often over the past year or so.  Take a look at last night’s ECMWF monthly run.  One map representing the average height anomalies for each week.

500za_week1_bg_NA

500za_week2_bg_NA

500za_week3_bg_NA

500za_week4_bg_NA

Same sort of splitty pattern we’ve seen recently with lower than normal heights to our south and higher than normal to our north and northwest.

Chief Meteorologist Mark Nelsen