The Weather Wire July 2018 Volume 25 Number 7 Contents: Wildfires Burning Across Colorado Drought Monitor June Summary/Statistics July Preview Rainfall Totals Wildfires Burning Across Colorado Following a drier than average winter and spring across most of Colorado, especially southern and western parts of the state, it comes as little surprise that fire season is off to an active start. Several large fires have been burning across Colorado over the past month, with a more noticeable uptick occurring over the last week of June as hot and dry conditions prevailed. Below is a map showing the current locations of large active wildfires in Colorado as of July 2 nd. There are currently 7 major fires burning, ranging in size from 1,400 acres to 95,000 acres.
Here is a current summary of a few of the major ongoing fires in Colorado, as of July 5 th. 416 Fire (San Juan Mountains, north of Durango) The 416 Fire started on June 1, and has been burning for over a month now and is 45% contained. The cause of the fire remains unknown. The fire is located about 13 miles north of Durango and has burned 53,260 acres so far. The popular Durango-Silverton Scenic Railroad was forced to close due to the fire earlier in June, but has since opened back up with limited operations. Much of the San Juan Mountains have been impacted significantly by smoke from this fire. Spring Creek Fire (Sangre de Christo area, near Ft. Garland) The Spring Creek Fire started on June 27, and has rapidly grown to 95,739 acres in just over a week with only 5% containment. This is currently the largest fire burning in Colorado, and at this time is the 3 rd largest fire in Colorado s history. Unfortunately, this fire was human-caused and a suspect has been arrested and charged with arson. Extreme fire behavior in recent days has fueled rapid growth, with hot, dry, unstable, and windy conditions present. Gusty and erratic outflow winds from dry thunderstorms have impacted the area recently, and continue to be a concern during the first few days of July. Weston Pass Fire (Park County, north of Buena Vista) The Weston Pass Fire was started by lightning on June 28, and has grown to 10,727 acres with 15% containment. The fire is located between Buena Vista and Fairplay in area of mixed conifer forest, aspen forest, brushy vegetation, and grass/sagebrush. Dry, breezy conditions continue to impact this area into early July, resulting in moderate to high fire behavior. Lake Christine (near Basalt in the Roaring Fork Valley) The Lake Christine Fire just recently started on July 3 rd and has already grown to 2,373 acres with 0% containment. Warm and dry weather along with breezy conditions have resulted in extreme fire behavior, and has also forced evacuations. The cause of this fire is currently under investigation.
Badger Creek Fire (Wyoming/Colorado border in the Medicine Bow Mountains) The Badger Creek Fire is located near the Colorado/Wyoming border in the Medicine Bow Mountains, and currently stands at 21,196 acres with all of this remaining on the Wyoming side of the border at this time. The fire started on June 10, but is now 80% contained. The cause of the fire remains unknown. Periodic hot, dry, and breezy conditions have continued to result in challenging fire behavior at times. Potential for moisture will gradually increase as monsoon season arrives As monsoon season approaches, there is some hope that portions of Colorado could begin to see some beneficial moisture. At this time, longer range models are projecting an increase in moisture across Western Colorado during the second week of July, with a more active monsoon likely over the second half of the month. Still, breaking out of a persistently dry pattern can take some time, often longer than models project, so it remains to be seen how the rest of the summer plays out. NOAA is projecting a wetter than normal July-September period for the western two-thirds of Colorado, as seen in the image below.
The National Interagency Fire Center is also predicting Near Normal fire potential during the month of July (see image below), as opposed to the above normal activity that was correctly predicted during the month of June. This likely takes into account the prediction for an active monsoon to develop this month. As challenging fire weather concerns continue through the first week of July, it may take a little while for improvement to occur, but hopefully Colorado will begin to see improvements with regards to moisture by later in the month. Drought Update Colorado has seen little change with regards to drought conditions over the past month. The southern two-thirds and western-third of Colorado remain under drought, with extreme to exceptional drought conditions persisting across the southern third of the state. Northeast Colorado, including Denver and Boulder, remains drought-free, as does north central Colorado, although abnormally dry conditions are present from Summit County north to the Wyoming border along the Continental Divide. Extreme drought conditions continue across much of the Four Corners region as well with pockets of moderate to severe drought over the far western states.
The map below shows forecasted temperature deviances for July 2018. There is a slight bias toward above normal temperatures across southern and eastern Colorado, with equal chances for above or below normal temperatures across northwestern Colorado.
The map below shows forecasted precipitation deviances for July 2018. There is a slight to moderate bias toward above normal precipitation across the western half of Colorado, with equal chances for above or below normal precipitation across the eastern half of Colorado. Drought conditions are expected to persist across most of Colorado this month, while North Central and Northeast Colorado is expected to remain drought-free. Improvement in drought conditions is expected across Arizona and the southern half of Utah, where an active monsoonal pattern is predicted this month.
June Summary June 2018 was much hotter and drier than average across the Front Range and Northeast Colorado. The average high for the month at DIA was 88.8, which is 6.4 degrees above normal, and the average low for the month was 56.0, which is 3.7 degrees above normal. The overall average temperature for the month was 5.0 degrees above normal, making it the 7 th warmest June on record in Denver. During the last week of June, an impressive heat wave occurred across Eastern Colorado, with DIA recording highs of 101 and 105 on the 27 th and 28 th, respectively. The high of 105 on the 28 th was a daily record high, and also tied the all-time record for Denver, which was originally set in 1878 and tied in 2005 and 2012. However, should be noted that records were moved from Stapleton to DIA in the mid-2000 s, and on June 28 th the high temperature at Stapleton was 104, which is just shy of the original all-time record set prior to the move to DIA. Regardless, this was an extreme heat wave by local standards. For the month, there were a total of 16 days at DIA in which the high temperature reached 90 or higher, which is double the average for the month. There were only 8 days during the month with below average temperatures. The low for the month of 44 occurred on the 2 nd. Precipitation for the month was below average across the entire region. DIA only recorded 0.43 of rainfall during the entire month, which is well below the average value of 1.98. From Ft. Collins to Colorado Springs, rainfall amounts generally ranged from 0.50-1.50 during June. Downtown Denver recorded 1.00 of rain for the month. Although conditions were drier than normal overall, there were several active days featuring severe thunderstorms across the region, including large hail events on the 18 th and 19 th, especially in Boulder County and to a somewhat lesser extent in the Denver metro area. Colorado experienced an active month for wildfires in June as
hot and dry conditions prevailed statewide, with new fires starting in the mountains west and south of Colorado Springs during the final week of the month. June Stats TEMPERATURE (IN DEGREES F) AVERAGE MAX 88.8 NORMAL 82.4 DEPARTURE 6.4 AVERAGE MIN 56.0 NORMAL 52.3 DEPARTURE 3.7 MONTHLY MEAN 72.4 NORMAL 67.4 DEPARTURE 5.0 HIGHEST 105 on 6/28 LOWEST 44 on 6/2 DAYS WITH MAX 90 OR ABOVE 16 NORMAL 7.9 DAYS WITH MAX 32 OR BELOW 0 NORMAL 0.0 DAYS WITH MIN 32 OR BELOW 0 NORMAL 0.0 DAYS WITH MIN ZERO OR BELOW 0 NORMAL 0.0 TEMPERATURE RECORDS 6/5 Daily record high of 95 tied 6/9 Daily record high of 95 tied 6/28 Daily record high of 105 set, monthly record tied HEATING DEGREE DAYS MONTHLY TOTAL 9 NORMAL 62 DEPARTURE -53 SEASONAL TOTAL 5410 NORMAL 6058 DEPARTURE -648 COOLING DEGREE DAYS MONTHLY TOTAL 241 NORMAL 133 DEPARTURE 108 YEARLY TOTAL 289 NORMAL 155 DEPARTURE 134 PRECIPITATION (IN INCHES) MONTHLY TOTAL 0.43 NORMAL 1.98 DEPARTURE -1.55 YEARLY TOTAL 5.02 NORMAL 7.51 DEPARTURE -2.49 GREATEST IN 24 HOURS 0.25 on 6/17 DAYS WITH MEASURABLE PRECIP. 5 SNOWFALL (IN INCHES)
MONTHLY TOTAL 0.0 NORMAL 0.0 DEPARTURE 0.0 SEASONAL TOTAL 25.7 NORMAL 53.8 DEPARTURE -28.1 GREATEST IN 24 HOURS NA GREATEST DEPTH 0 WIND (IN MILES PER HOUR) AVERAGE SPEED 10.5 mph PEAK WIND GUST 57 mph from the S on 6/27 MISCELLANEOUS WEATHER NUMBER OF DAYS WITH THUNDERSTORM 12 NORMAL 10 NUMBER OF DAYS WITH HEAVY FOG 1 NORMAL <1 NUMBER OF DAYS WITH HAIL 0 NUMBER OF SUNNY DAYS 11 NUMBER OF PARTLY CLOUDY DAYS 16 NUMBER OF CLOUDY DAYS 3 AVERAGE RELATIVE HUMIDITY 42% July Preview July is the hottest month on average in Denver, but also the second wettest on average due to the high frequency of thunderstorms that occur. The average high temperature for the month of July is 89.4 degrees, and the high exceeds 90 degrees an average of 16 days during the month. The record high for the month is 105, which occurred in 2005, and this is also tied for the hottest temperature on record in Denver. The average low for the month is 58.9 degrees and the coolest temperature on record is 42, which occurred way back in 1873 and again in 1903. Average rainfall during the month of July is 2.10, with an average of 11 thunderstorm days occurring during the month. The North American Monsoon typically ramps up and peaks during the second half of July, which supplies the moisture necessary for frequent thunderstorms to occur in the Denver metro area, and sometimes heavy rainfall can occur from these thunderstorms. Severe weather is common during July as well, even though the peak is typically in June. However, the biggest threats from thunderstorms gradually shift from severe weather to heavy rain and flash flooding as the month progresses. This is typically due to the fact that upper level winds gradually weaken as the summer wears on, resulting in slower-moving thunderstorms, which can produce heavier rainfall during active monsoonal periods. Some of the Front Range s more notable flash flooding events have occurred in July, such as the Big Thompson Flood in 1976 and the Ft. Collins flood in 1997. For July of 2018, we are expecting slightly above average temperatures and near average rainfall. The first half of the month is likely to feature hotter temperatures and below average rainfall as high pressure dominates the pattern, while significant monsoonal moisture has not yet become established over Colorado as of the
first week of July. The middle to latter portion of the month should feature better chances for meaningful rains and an overall moderation in temperatures, as an active monsoonal pattern is projected to develop. TEMPERATURE DENVER'S JULY CLIMATOLOGICALLY NORMAL (NORMAL PERIOD 1981-2010 DIA Data) AVERAGE HIGH 89.4 AVERAGE LOW 58.9 MONTHLY MEAN 74.2 DAYS WITH HIGH 90 OR ABOVE 16 DAYS WITH HIGH 32 OR BELOW 0 DAYS WITH LOW 32 OR BELOW 0 DAYS WITH LOWS ZERO OR BELOW 0 PRECIPITATION MONTHLY MEAN 2.10 DAYS WITH MEASURABLE PRECIPITATION 8 AVERAGE SNOWFALL IN INCHES 0.0 DAYS WITH 1.0 INCH OF SNOW OR MORE 0 MISCELLANEOUS AVERAGES HEATING DEGREE DAYS 6 COOLING DEGREE DAYS 289 WIND SPEED (MPH) 8.3mph WIND DIRECTION South DAYS WITH THUNDERSTORMS 11 DAYS WITH DENSE FOG 0 PERCENT OF SUNSHINE POSSIBLE 71% EXTREMES RECORD HIGH 105 on 7/20/2005 RECORD LOW 42 on 7/4/1903, 7/31/1873 WARMEST 78.9 in 2012 COLDEST 67.4 in 1895 WETTEST 6.41 in 1965 DRIEST 0.01 in 1901 SNOWIEST 0.0 LEAST SNOWIEST 0.0 Rainfall
May 2016 to October 2016 City May Jun Jul Aug Sep Oct Total Aurora (Central) 2.05 1.55 3.60 Boulder 4.75 1.69 6.44 Brighton 1.35 1.77 1.35 Broomfield 2.50 0.80 3.30 Castle Rock 2.26 0.70 2.96 Colo Sprgs Airport 1.46 1.43 2.89 Denver DIA 1.86 0.43 2.29 Denver Downtown 2.96 1.00 3.96 Golden 2.54 1.11 3.65 Fort Collins 4.98 1.45 6.43 Highlands Ranch 2.25 1.17 3.42 Lakewood 3.66 0.91 4.57 Littleton 2.40 0.69 3.09 Parker 2.29 1.64 3.93 Sedalia - Hwy 67 2.33 0.45 2.78 Thornton 1.74 1.08 2.82 Westminster 2.10 0.72 2.82 Wheat Ridge 2.66 1.07 3.73 Skyview Weather 2350 N Rocky View Rd Castle Rock, CO 80108 Phone: (303) 688-9175 Fax: (303) 380-3338 E-mail: Tim@SkyviewWeather.com On the web at www.skyviewweather.com Copyright 2018 Skyview Weather