UPDATE: Summary of Southwest Heat Event through July 2nd
On Tuesday, July 2nd Redding, California measured 116°, just 2° short of their all-time record. Death Valley had a low of 104° on July 2nd, its second hottest night on record since 1920 (hottest was just last summer!). It has been an amazing past six days (June 27-July 2) heat-wise in the West. Many significant heat records have been broken. This is a daily update (July 3rd) on the latest with also some new information about earlier events.JUNE 27, 2013
The heat wave began to evolve on June 27th with a dome of upper air high pressure centered over northern New Mexico. That day brought an all-time heat record for any location in Santa Fe
of 102° at the airport (and a near record 98° to the downtown area). Albuquerque
registered 105°, tying their 2nd highest temperature on record (following 107° set on June 26, 1994). See my previous log about the Santa Fe temperature extreme.Maps of 500 mb contours at 7 a.m. June 27th (top) and temperatures observed on June 27th bottom. Although the caption for the temperatures say “June 28” that is because the map was published at 7 a.m. June 28th but it actually reflects the max/min temperatures for the previous day (June 27th). This, of course holds true all the following maps as well.
NOAA/NCDC Daily Weather Maps.JUNE 28, 2013
By June 28th, last Friday, the dome had slid to the west and become centered over southern Utah. Salt Lake City
hit 105° on June 28th, the hottest June temperature on record (previous 104° June 21, 1961). Red Bluff, California
reached 110° (not a record) and a site called Iron Mountain in southern California reached 127° (their warmest temperature on record-POR back to 1935) smashing their all-time previous record of 122° set on July 17, 1998 and July 19, 2005 according to the COOP site information received just today (July 1st). The official Death Valley site at Furnace Creek reached 125°, a daily record (note that earlier this month Death Valley measured a record early-season temperature of 126° on June 8th! Zion National Park
in Utah measured 114°, their warmest June temp on record and only 1° short of their all-time record of 115 set on July 1, 1950. Temperature records go back to 1904 at Zion.Maps of 500 mb contours at 7 a.m. June 28th (top) and temperatures observed on June 28th (bottom).
NOAA/NCDC Daily Weather Maps.JUNE 29, 2013
On Saturday, June 29th, the dome of high pressure had migrated slightly to the south and centered over northern Arizona. The following all-time June monthly records were set:
100° Ely, Nevada
(previous 99° June 22, 1954)
101° Eureka, Nevada
(previous 98° on two occasions)
105° Salt Lake City, Utah
(again, see June 28)
122° Palm Springs, California
(tied June 28, 1994) and 1° short of all-time record of 123° set on August 1, 1993
128° Death Valley, California
(tied previous 128° set on June 29, 1994)
It was 119° in Phoenix, Arizona
their 4th warmest reading on record.Maps of 500 mb contours at 7 a.m. June 29th (top) and temperatures observed on June 29th (bottom).
NOAA/NCDC Daily Weather Maps.JUNE 30, 2013
On Sunday June 30th the high pressure dome became centered over the southern tip of Nevada. Amazing temperatures resulted. All-time records for heat were set at Lancaster, California:
115° (previous record 114° on July 18 and 19, 1960) and tied at Las Vegas, Nevada
with a 117° reading (also on July 19, 2005 and July 24, 1942). Overton, Nevada hit 122°, the warmest reading in Nevada for the heat wave. It was 123° in Bullhead City for Arizona's hottest for the entire event.
All-time June monthly records were set or tied at:
104° Elko, Nevada
(previous 104° June 24, 1981)
103° Tonopah, Nevada
(previous 102° on two occasions), this was also just 1° short of their all-time record of 104° set on July 18, 1960).
106° Winnemucca, Nevada
(previous 106° on June 24, 1988)Maps of 500 mb contours at 7 a.m. June 30th (top) and temperatures for June 30th (bottom).
NOAA/NCDC Daily Weather Maps.
But the grand daddy of all was the official 129° at Furnace Creek, the official weather site for Death Valley. In fact the temperature actually reached 129.2°, which is the hottest reliably measured temperature on earth for the month of June.A photograph of the official Furnace Creek, Death Valley maximum recording thermometer at time of observation on Monday morning July 1st (which was for the maximum temperature measured on June 30th). Observations at the site are made only at 4 p.m. and 7 a.m. daily. The shelter door is not opened at any other time in order to not affect the ambient air temperature inside the shelter. You may have seen a different image of this same thermometer on the NWS-Las Vegas web site posted today (July 1st) that shows the temperature just shy of 129°. That is because THAT photograph was taken after the thermometer had been removed from its shelter and turned vertically, which caused the mercury to slip down the tube about 0.3°F. This photograph was taken prior to the thermometer being removed from the shelter.
Photo courtesy of Death Valley National Park and NWS-Las Vegas.An analysis of the above photograph illustrates that the maximum temperature recorded at the official Furnace Creek, Death Valley site on June 30th was, in fact, 129.2° by calculating the horizontal and vertical placements by pixel length (using an enlargement of the original photo). Officially, the temperature in Death Valley is rounded off to the nearest full degree Fahrenheit, so the official daily maximum on June 30th was 129°. However, we can see that in reality it reached 129.2°, by our best calculation, and thus would be the hottest reliably measured temperature for the month of June on earth.
Pixel analysis by Nick Wiltgen of The Weather Channel.JULY 1, 2013500 mb chart for July 1st. The heat dome has drifted northward to northern Nevada. Temperatures have eased over the far Southwest but ramped up over Idaho and the interior Northwest. Temperature map for July 1st not yet available.
NOAA/NCDC Daily Weather Maps.
On July 1st the temperature again reached record territory in Death Valley with a reading of 127°. However, the worst of the heat has migrated northwards and Boise, Idaho
reported 110°, tying its 2nd hottest temperature on record (set on three previous occasions, last time being July 13, 2002) following a 111° reading on July 19, 1960 and also on July 12, 1898. St. George, Utah reached 113° for their warmest reading of the heat wave.
JULY 2, 2013Redding, California
reached 116°. This site is at the north end of the Sacramento Valley and Tuesday' 116° was just 2° short of their all-time heat record of 118° last set on July 20, 1988. In Oregon, the town of Rome hit 108° (a daily record) with the RAWS site of Beverly 5 E peaking at 111°. Missoula, Montana
reached 100° and St. Regis (at 2,692' elevation) reached 105°. Butte, Montana
set a daily record high of 95° (previous 93° in 1996). The triple-digit heat worked its way up into British Columbia, Canada where Penticton hit 101°. Death Valley
had another day at 127° but this followed its warmest night yet so far during the prolonged heat wave with a minimum of 104° (on the official mechanical thermometer! Death Valley's warmest night on record was set just last summer when the temperature failed to drop below 107° on July 12th. Las Vegas hit 115°, tying the daily record high with 1937 and 1950.All-time warmest June on record for several sites
Meanwhile, this past June was the warmest such on record for Tucson, Arizona
with an average of 89.5°, (previous 89.2° in June 1994). For the first time on record every single day in June reached 100° or greater. Phoenix and Las Vegas
also reported their warmest June on record with 94.8° at Phoenix (previous 94.6° in June 2006) and 91.5° at Las Vegas (previous 90.5° also in June 2006). It was also Death Valley's warmest June on record with an average of 101.3° and also for Needles, California with 95.8°.Hot nights as well
Salt Lake City had a calendar day minimum of 80° on Sunday, June 30th, tying for its warmest such with July 16, 2003. Likewise, Las Vegas had a minimum of 95° on July 1st, tied with its other hottest night on record July 19, 2005.
I just mentioned Death Valley's 104° minimum on July 2nd. This would rank as its 2nd hottest night on record (after last summer's 107° on July 12th) if one discounts some dubious readings from the 1917-1920 era: those were 110° on July 5, 1918, 106° on August 1, 1920, and 105° on July 11, 1920 and July 22, 1917.
Of course, there have been many other all-time, monthly, and daily records set throughout the region the past five day, these are just the highlights. The ore of the heat is moving north and on Wednesday July 3rd we may see more records in the Montana, Oregon, and Washington area.
Christopher C. Burt