Have We Seen the Coldest Of Winter?

January 27, 2016

11pm Wednesday…

Whew, a busy day for the news folks.  That means not much focus on the weather despite record highs at Salem and Roseburg.

PLOT_Highs_ORWA

Here in Portland there was just enough easterly flow to keep us “cool” at 54 degrees…two degrees below the record for the date.  Note that the 47 degree low “today” (calendar day) is the warmest low temperature since early January.  We haven’t seen frost in almost 3 weeks here in the city either.  A very mild 2nd half of January for sure after a nice and chilly start!

That brings up the question people often ask me this time of year (when temps start to warm).  “Has the coldest weather of winter passed on by?“.  I think that’s quite possible this year.  First, we’ve dropped to 24 at PDX twice in late November.  Then and again in early January the colder suburbs dropped into the upper teens.  Compare that with the past few years:

MarkColdestNightLows_Yearly

If we only have a low of 24 that’ll be a bit on the warm side, although not too unusual.  Look at the low temperatures over the past 20 years.  The title refers to last winter, although it may end up being correct for this winter too.

MarkWinter_ColdestDay

Take a look at a neat graphic from Climate Matters, showing the average date of the coldest winter temperature

2016ColdestDays_CONUS

We already know our coldest winter temperatures are often in late December, but you can see here it tends to be later in the winter in the Eastern USA, especially in the northern areas.  That’s because widespread mid/late winter snow cover reflects the sunlight well over there.  A wide open path for arctic airmasses to move south over the snow-covered terrain doesn’t hurt either.

The last two big El Ninos featured mild January/February weather so I think it’s UNLIKELY we have anything colder than 24 in the next 5-6 weeks.  Of course we know it’s POSSIBLE this late, but it seems unlikely this year.

Chief Meteorologist Mark Nelsen