Northern Blue Mountains of Oregon

 Public Information Statement  Statement as of 7:11 PM EDT on August 4, 2015

410 PM PDT Tue August 4 2015

... Month in review for northeast Oregon and southeast Washington for
the month of July 2015...

... Warmer and drier than average once again for most locations...

I. Temperature and precipitation overview

July average temperatures were above normal across the region for the
calendar month ranging from approximately 2 to 6 degrees above normal.
Both maximum and minimum temperatures averaged above normal for the
month, with maximum temperatures mainly between 2 to 7 degrees above
average, and minimum temperatures between 1 to 6 degree(s) above
average. Total precipitation was below normal for most locations,
ranging from less than 5 to about 75 percent of normal. A few locations
in the Oregon mountains did have above normal precipitation due to
thunderstorm activity in the area. To summarize conditions were hot and
generally dry across much of the area during the month of July. Several
daily and monthly records were broken throughout the month.

July 2015 data and departure from normal for selected cities:

                   Max dep min dep Ave dep pcpn dep
                   temp norm temp norm temp norm totl norm

La Grande 87.6 +2.2 55.0 +1.2 71.3 +1.7 0.05 -0.63
Pendleton Airport 91.6 +3.6 60.6 +3.4 76.1 +3.5 T -0.32
Redmond 87.0 +1.4 47.9 +1.7 67.5 +1.6 0.44 -0.09
The Dalles 92.7 +5.2 64.8 +4.4 78.7 +4.7 T -0.16
Walla Walla 93.0 +3.8 66.7 +5.8 79.9 +4.9 0.04 -0.55
Kennewick 94.6 +4.3 66.3 +4.6 80.4 +4.4 0.00 -0.22
Yakima 94.8 +6.9 59.4 +6.1 77.1 +6.5 0.06 -0.16


ii. Selected records

The first week of July saw a continuation of the hot weather that was
experienced throughout most of the previous month. High temperatures in
many of the lower elevations ranged from 98 to 108 during this time
period, which is about 8 to 15 degrees above average. Near and just
after the 4th of July there was also some shower and thunderstorm
activity, especially over central Oregon and the mountains of northeast
Oregon. The middle ten days of the month saw temperatures cooling back
to near average levels with mainly dry conditions. The only exception
to this was across central Oregon where a few rounds of showers and
embedded thunderstorms again occurred from the 10th through 14th of the
month. From the 21st through the 28th temperatures went on another
cooling trend, with temperatures averaging about 3 to 10 degrees below
normal. During this time it was mostly dry across the region, except
for some isolated shower activity. The final 3 days or so of the month
saw a quick warming trend, with high temperatures again reaching into
the upper 90s and lower 100s in the valleys and basins.

The following table lists the weather station, rank of the 1-day record
warmest maximum temperature for July, the record temperature with date
of occurrence, the current all-time record temperature for July, or the
previous record in cases where 2015 is the new record.

City rank July 2015 Max T July Max T record

Yakima, WA #3(t) 107 on 7/03 & 7/31 109 on 7/23/2006
The Dalles, or #4 109 on 7/31 111 on 7/26/1998
Ellensburg, WA #5(t) 105 on 7/31 107 on 7/08/2012
Moxee City, WA #5(t) 103 on 7/31 105 on 7/12/2002
Meacham, or #6 96 on 7/31 103 on 7/08/1960
Satus Pass, WA #7(t) 100 on 7/03 & 7/4 103 on 7/23/2006

Thus far in 2015 (through August 3rd) many locations around the region
have experienced the top 3 number of 100+ degree days. A few locations
have even set a new record for the number of 100+ degrees days through
August 3rd. It remains to be seen if any records will stand after the
Summer is over. It is not uncommon to see additional 100 degree days
through much of August, although looking at the climatic record it
becomes exceedingly rare to reach 100 degrees after the first week of
September. The weather pattern for at least the next 8-14 days is not
particularly favorable for additional 100+ degree days in our area.

City rank number of 100 degree previous or current
                     days through Aug 3rd 2015 record number and year

Pendleton, or #1(t) 10 days 10 in 1971
Moro, or #1 07 days 05 in 1938
Yakima, WA #1 22 days 09 in 1971
Hermiston, or #1 17 days 13 in 1971
Ellensburg, WA #1 13 days 06 in 2014
The Dalles, or #1 13 days 10 in 1985
Dayton, WA #1(t) 07 days 07 in 1968
Walla Walla,WA #2 13 days 14 in 1985
Goldendale, WA #2(t) 07 days 08 in 1971
Kennewick, WA #3 16 days 18 in 1906

The mean synoptic pattern for the month of July 2015 was characterized
by an anomalous ridge of high pressure just off Pacific northwest
coast. There was a stronger ridge up over the Arctic Ocean with an
undercutting trough out in the off the Southern California coast
extending across the intermountain west and plains states. Below is a
list of the stations that set an all-time record warm daily minimum
temperature in the month of July, also listed is the ranks, July 2015
warm minimum temperatures and the previous warmest July minimum temperature.

City rank July 2015 min T previous or current
                                                    warmest July min T

Ellensburg, WA #1 74 on 7/03 & 7/04 73 on 7/14/2014
Moxee City, WA #1 78 on 7/05 74 on 7/10/2007
Yakima, WA #1(t) 76 on 7/03 76 on 7/13/2002
Hermiston, or #2 74 on 7/07 & 7/20 75 on 7/13/2002
Prosser, WA #4(t) 75 on 7/05 85 on 7/27/1925
Walla Walla, WA #9 76 on 7/04 80 on 7/13/2002


Numerous locations set top 5 warmest average minimum temperatures in
July 2015. The following table lists the location, the rank, the
average July low temperature, and the record warmest average July low
temperature, or the previous record when July 2015 is the new record.


City rank July 2015 previous or current warmest
                             avg min T July avg min T

Walla Walla, WA #1 66.7 66.3 in 2007
Ellensburg, WA #1 60.3 60.1 in 2007
Moxee City, WA #1 58.8 58.5 in 2014
Prineville, or #1 53.1 52.1 in 1926
The Dalles, or #2 64.8 66.3 in 1985
Condon, or #2 55.2 56.9 in 2014
Heppner, or #2 58.3 61.8 in 1906
Hermiston, or #3 61.0 61.6 in 1998
Kennewick, WA #3 66.3 70.7 in 1906
Richland, WA #3 63.9 65.8 in 1958
Pelton dam, or #3 56.3 57.0 in 2007
Yakima, WA #4 59.4 60.6 in 2014
Goldendale, WA #4 54.0 55.0 in 1998
Moro, or #4 58.0 58.6 in 1976
Madras, or #5 49.3 53.9 in 2007
Long Creek, or #5 48.8 51.0 in 2003

Through a combination of the hot start to the month, mild conditions
mid-month and the fast warm up at the end of the month several
locations were able to record their warmest average Max temperature for
the month of July. Listed in The Table below is the location, rank,
average Max temperature for July 2015 and either the record warmest
average Max temperature for the month of July, or the previous record
in cases where July 2015 is the new record.

City rank July 2015 previous or current warmest
                               avg Max T July avg Max T

The Dalles, or #3 90.0 96.8 in 1985
Ellensburg, WA #3 91.5 92.0 in 2013
Satus Pass, WA #3 88.2 90.2 in 2003
Yakima, WA #3 94.8 95.4 in 2013
Hermiston, or #8 94.2 96.6 in 2014
Whitman mission, WA #8 93.2 97.4 in 1985
Moxee City, WA #9 90.8 92.8 in 2014
Cle Elum, WA #10 85.6 91.8 in 1958

through a combination of the hot start to the month, mild conditions
mid-month and the fast warm up at the end of the month several
locations were able to record their warmest average temperature for the
month of July. Listed in The Table below is the location, rank, average
temperature for July 2015 and either the record warmest average
temperature for the month of July, or the previous record in cases
where July 2015 is the new record.

City rank July 2015 warmest July
                                  avg T avg T

The Dalles, or #2 78.7 81.6 in 1985
Ellensburg, WA #2 75.9 76.2 in 2014
Moxee City, WA #2 74.8 75.7 in 2014
Condon, or #3 71.3 73.1 in 2014
Yakima, WA #3 77.1 77.8 in 2014
Walla Walla, WA #3(t) 79.9 82.3 in 1985
Hermiston, or #4 77.6 78.5 in 2014
Kennewick, WA #4 80.4 86.3 in 1906
Cle Elum, WA #5 70.5 72.4 in 1958
Arlington, or #5 80.0 82.8 in 1985
Moro, or #5 72.7 73.5 in 1985
Satus Pass, WA #5 68.9 69.8 in 1998

Precipitation totals were well below normal in many locations which
lead to several top 10 lowest precipitation records and a few locations
tied for their driest July on record. Listed below are the locations,
rank, July 2015 precipitation and the lowest recorded precipitation for
July. A (t) means that the record tied with other previous dates/years.
The combination of the hot and dry weather also lead to several days of
fire weather concerns throughout the month.


City rank July 2015 precip lowest July precip

Arlington, or #1(t) 0.00 inches 0.00 inches in 2013*
Cle Elum, WA #1(t) 0.00 inches 0.00 inches in 1984*
Dayton, WA #1(t) 0.00 inches 0.00 inches in 1984*
Kennewick, WA #1(t) 0.00 inches 0.00 inches in 2013*
Moxee City, WA #1(t) 0.00 inches 0.00 inches in 2006*
Pendleton, or #3(t) trace 0.00 inches in 1931*
Whitman mission #3 trace 0.00 inches in 2013*
Ellensburg, WA #4(t) 0.01 inches 0.00 inches in 2003*
The Dalles, or #6(t) trace 0.00 inches in 2003*

* indicates that this record occurred in other previous years

Iii. Significant weather

There were two periods with showers and thunderstorms across parts of
the region during the month of July. The first active period was from
July 5th though the 6th and affected mainly central Oregon and the
mountains of northeast Oregon. A weak weather system initiated
scattered thunderstorms over central Oregon during the afternoon hours of
July 6th. During the next active period from July 10-14th a stronger
weather system with ample mid-level moisture and instability helped to
develop scattered thunderstorms over much of the area during the
afternoon/evening hours on July 10-14th . A few of these storms produced
brief heavy downpours and frequent cloud to ground lightning.

Listed below are Sample rainfall reports from the July 5-6th event:

2sw Redmond, or 1.15 inches
Tumalo, or 0.92 inches
10s Maupin, or 0.35 inches
Redmond, or 0.20 inches
Bend, or 0.20 inches
3e Sisters, or 0.10 inches

Listed below are 5 day Sample rainfall reports from the July 10-14th event:

6e Paulina, or 1.34 inches
Redmond, or 0.23 inches
7ne Bend, or 0.21 inches
2w Bend, or 0.18 inches
Yakima, WA 0.06 inches
Walla Walla, WA trace
3ne Prineville, or 1.39 inches
Meacham, or 1.21 inches
Pendleton, or trace
Joseph, or 0.48 inches
5s Mount Vernon,or 0.80 inches

During the July 25-28th period there was also a rather significant cool
down over the area. High temperatures fell back into the 70s and lower
80s for the valleys and basins of the area with 60s in the mountains.
This was about 3 to 8 degrees below the seasonal average. The cool down
was caused by a pattern reversal as an upper level trough developed
over much of western North America. The trough axis extended from
Alaska down into the Pacific northwest. In general conditions stayed
dry over much of our area, but temperatures cooled up to 20 degrees
from where they were earlier in the month.

During the last two days of the month and continuing into the first few
days of August a ridge of high pressure redeveloped over the area
allowing temperatures to warm to above average levels once again.


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