Today, on the three year anniversary of Hurricane Katrina, preparations are underway along the Gulf Coast for the possibility that Tropical Storm Gustav will strike the region next week. At 3:00am MDT Friday Gustav had tropical storm strength sustained winds of 65mph extending out 140 miles however it is fully expected to become a hurricane today. It possibly could increase in intensity to a category four storm with 130mph winds by the time it makes landfall toward the beginng of next week.
Gustav's current predicted track as of Friday morning.
It goes without saying that the storm presents a serious threat to life and property with landfall expected late Monday or early Tuesday. The greatest danger lies between Houston, TX and Mobile, AL but anywhere along the Gulf Coast remains at risk for a hit from the storm. State, federal and local officials are preparing for the worst as they should. Disaster declarations have been issued by Louisiana Governor Bobby Jindal and Texas Governor Rick Perry. Mississippi Governor Haley Barbour has declared a state of emergency. New Orleans Mayor Ray Nagin is expected to issue an evacuation order for the city, but it likely would not go into effect until Saturday.
Hanna's current predicted track as of Friday morning.
Tropical Storm Hanna, while less of a threat for the United States, also bears watching. Hanna currently has winds of 50mph and should remain near those levels today but it is expected to become a hurricane in the coming days. The storm this morning was located about 245 miles north-northeast of the northern Leeward Islands. Hanna’s track at this point is uncertain. A system currently over the Great Lakes could force Hanna to turn to the northeast thus missing any major land features.
As temperatures start to drop, September reminds us that summer is at an end and fall is now here. Sunshine is predominant though as the month actually has the highest percentage of sun out of any month. Sunny days and clear, cool nights are the standard weather pattern for the month.
Photo of the tornado near Parker. Image courtesy Jeff Smith and 9News.
Three tornadoes and multiple funnel clouds were reported in Elbert and Douglas counties Sunday evening. At 5:31pm the Centennial Airport tower reported a tornado on the ground five miles southwest of Parker. This was followed by a second tornado reported at 5:47pm six miles northeast of Parker. Lastly, a third twister was spotted three miles west of Castle Rock reported by trained spotters at 6:03pm.
News video showed the tornadoes weaving through relatively unpopulated areas interspersed wtih some houses. Authorities currently report no major damage.
Tornado warnings were issued but have now expired. As always, please be aware of the weather situation around you and when a danger presents itself, take appropriate action.
Update, 8/25/08, 7:50am – Reports are varying on the actual number of tornadoes that touched down. We have seen reports as low as two twisters to as many as a dozen. Chances are the actual number is toward the lower end of that range as oftentimes the same tornado is reported by multiple spotters with different descriptions of their locations. The National Weather Service investigates these and at some point in the future will determine the true number of tornadoes.
Park County tornado near Eleven Mile Reservoir. Image courtesy 7News and Jerry Bivens.
In a truly unusual weather occurence, a tornado struck near Eleven Mile Reservoir in Park County Saturday afternoon. Certainly we are all used to hearing about twisters along the Front Range and on the plains but mountain tornadoes are quite rare – the rugged terrain usually disrupts the weather patterns necessary to product tornadoes. Authorities estimate five vehicles were damaged including a motorhome and pickup truck camper that were overturned, a trailer was destroyed. Beyond cuts and scrapes, thankfully no one was injured.
Colorado is ranked ninth in the country with an average of 40 tornadoes a year. It is interesting to note that every state in the union – including Alaska and Hawaii – have had tornadoes.
Doing some research at the TornadoProject.com yields an interesting fact as well. This was Park County’s first tornado ever. That leaves 12 of Colorado’s 64 counties that have never had a tornado including:
Clear Creek
Dolores
Garfield
Gilpin
Gunnison
Hinsdale
Lake
Montrose
Ouray
San Juan
San Miguel
Summit
It does serve as a reminder that while the unofficial severe weather season is behind us, Colorado’s weather is anything but boring and everyone should be aware of all the types of weather hazards that are possible.
Storm Chasers on the Discovery Channel - the new season starts in October.
I was recently on the Discovery Channel’s website wondering when the next season of Storm Chasers was going to air. In looking around I found one of the show’s chasers, the operator of TornadoVideos.net, had compiled his own top 10 tornado videos. These are absolutely incredible!
For those that have never seen Storm Chasers, be sure to keep an eye out for it on Discovery when the next season starts in October. The upcoming season will feature lots of video from the record setting tornado season that just finished as well as the team’s new and improved Tornado Intercept Vehicle – a highly modified truck that they drive straight into tornadoes!
If August 2008’s weather thus far had to be summed up in one word it would be WET! Last Thursday a low pressure system began moving into the region from Saskatchewan, Canada. Ahead of the system a cold front moved into northeastern Colorado and by Friday that low pressure had settled over Colorado.
Over a three day period through Sunday morning, this produced lots of rain and record cool temperatures. As it stands today in fact, August 2008 has climbed to # 3 on the all-time wettest August’s on record – and we still have 12 days left in the month.
Denver’s top 5 wettest Augusts
5.85″ 1979
4.47 ” 1951
4.03″ 2008 (4.76″ recorded in Thornton)
3.87″ 1923
3.69″ 1991
While our August moisture has been great, it has not erased the deficit in precipitation overall for 2008. Up until this month, we had nine straight months with below average precipitation. Through the end of August, Denver historically averages 12.07 inches of precipitation. As of today, even with our record setting August, we only have recorded 7.31 inches in 2008. Certainly the recent storm highlights that we could easily catch up with one or two wet systems moving through but it does also serve as a reminder that we are still quite dry.
Record temperatures too! With the wet cold front came record setting cool temperatures too. Friday, August 15th, Denver reached 59 degrees which demolished the previous record low maximum temperature of 68 degrees set in 1880. Saturday, August 16th we reached 58 degrees which again broke the previous record low maximum for the date of 63 degrees set in 1890. ThorntonWeather.com recorded 58 and 57.2 on August 15th and 16th respectively.
Will Barrack Obama accept the nomination in rain or shine?
The last time one of the major political parties held a major part of their political convention outdoors was 48 years ago. On July 15, 1960 John F. Kennedy accepted his party’s nomination in the Los Angeles Coliseum before 50,000 people. Denver isn’t Los Angeles though and our weather is a lot more volatile than sunny southern California. As locals all know, the one thing consistent about Colorado weather is the inconsistency and that is true in the month of August.
As the end of the month comes, we start to notice our daylight hours getting fewer and even a bit of a chill in the early morning air. Historical temperature extremes for August are somewhat interesting. First, the highest temperature ever reached in Denver was actually recorded in August – 105 degrees on August 8, 1878 (also tied on July 20, 2005). Second, while there has never been snow in Denver in August, twice the mercury has dropped to 40 degrees to serve as a reminder the white stuff isn’t too far off – those occurrences were on August 22, 1904 and August 24, 1910.
On August 28th, the day Barrack Obama will accept the nomination, the normal high temperature is 83 degrees. Extremes? Our record high temperature for that day, set multiple times – most recently in 1969 – was 94 degrees. The lowest high temperature ever recorded on the 28th is 66 degrees in 1898.
Generally the chance for severe storms decreases in August but precipitation is not unusual at all. Cooler air near the surface helps to create a stable atmosphere thus keeping thunderstorms from usually becoming too intense. After the middle of August, tornadoes and damaging hail are pretty rare. The slow movement of storms this time of year are more likely to produce potentially heavy rain.
From midnight to noon convention visitors can usually expect clear conditions but it is the afternoon and evenings when things could get interesting. Those are the times when thunderstorms roll across the Front Range – typically 8 days a month have them, 9 with measurable precipitation.
Will weather be a factor for the DNC in 2008? We won’t know that until it gets closer but it could be interesting.
Updated Saturday, 8/16/08 @ 5:19am – Denver officially reached a high temperature of 59 degrees on Friday (Thornton reached 58). This crushed the old record low maximum temperature of 68 degrees set in 1880. Saturday has the potential to do the same with a forecast high of 56.
From a record setting heatwave just a couple of weeks ago to cool and wet and possibly record setting temperatures at the other end of the spectrum too! Colorado is nothing if not inconsistent! 🙂
A closed low has developed over much of Colorado and temperatures have dropped considerably and rain has fallen over much of the Front Range. Rain showers and isolated thunderstorms will dominate the weather Friday as will cool temperatures. Friday’s forecast high of 62 degrees is in fact 24 degrees below normal for this date. If that forecast holds true, we could set a record for the lowest high temperature for the date as well – the previous record is 69 degrees set in 1933! The same holds true for Saturday as well with a forecast high the same as Friday and the lowest high temperature on record of 68 degrees set way back in 1874.
The rain brings much needed moisture to the Front Range but it will be slow in falling and shouldn’t pose much in the way of flooding problems. As of this writing, the Rocky Mountain Weather Network is showing pretty consistent precipitation across the metro area with 0.29″ having fallen at ThorntonWeather.com so far. The moisture will be on and off through Saturday night and then begin decreasing Sunday and into Monday.
It looks like the first part of next week we will return to more seasonal weather and temperatures into the 80’s.
August is usually one of nicer weather months as summer winds down and temperatures cool. The Democratic National Convention will be in Denver August 25th to August 28th and chances are the weather will be just fine. A look back at historical weather events on those days though shows some interesting things have occurred in Denver weather history.
Some of the highlights in Denver weather history include:
August 1875 saw grasshopper swarms in Denver.
August 25
In 1875 in the period from August 19th to the 20th grasshoppers appeared in great numbers in Denver. Weather records say the “streets were literally covered with them” and swarms were seen on each day. All gardens in the city were ruined as were many rural crops. News stories say that on the 30th the grasshoppers were so numbers as to “almost darken the sun.”
In 1910, the lowest temperatures every recorded in August – 40 degrees – was recorded on August 24, 25 and 26.
In 1951 a microburst produced a 50 mph gust of wind at Stapleton International Airport. In 1964 thunderstorm winds gusted to 59 mph.
More recently, in 1994, lightning struck a power pole in Louisville causing a two hour power outage.
August 26
The aforementioned grasshopper plague and low temperatures occurred on this date.
In 1944 one of the most destructive hail storms in the city caused nearly one million dollars in damage as it struck between 2:00 and 3:00pm. Hail from very small to 1 ½ inches was reported and covered the ground to depths up to six inches in some areas. Downtown Denver recorded 0.95 inch of rain and heavy hail. News reports of the day report people being cut by broken glass, people being stranded by flooded cars, sewers backing up as they were unable to handle the deluge, buildings being flooded, trees stripped, telephone poles downed and more. The next day the American Red Cross was designated by the War Department to grant any and all priorities needed to repair the damage.
In 1961 two workmen suffered a broken foot and bruises when severe winds blew in the walls of a warehouse under construction.
On the 26th and 27th in 1980, two thunderstorms hit Arvada and Westminster dumping 1.5 inches of rain in an hour. Streets were washed out and homes and cars sustained damage. Three homes in Arvada sustained damage from lightning.
August 27
The 1875 grasshopper invasion continued.
Lightning is always a danger in Colorado.
In 1967 a young woman that was horseback riding in west Denver was killed when she was struck by lightning; the horse died soon thereafter. Another woman and young man riding with her were injured when they were thrown from their horses. Lightning also did damage to houses in Arvada in 2003 and Parker in 2005.
1996 saw some excitement in the Fort Lupton area when 2 – 3 inches of rain fell in a 45 minute span. A local college suffered damage when its roof leaked. A weak F0 tornado was also reported in the area.
Not so long ago in 2002 large hail struck the metro area on this date. Hail as large as 2 inches was reported in Jefferson County as well as 1.5 inches in Golden and Lakewood, 1 ¼ inches in Nederland, and 1 inch hail in Elizabeth, Louviers, Rollinsville and Blackhawk.
2004 saw a cold spell hit the Denver area. That year on the 27th the high temperature only reached 55 degrees setting a record low maximum for the date. The low temperature of 48 tied the record low as well.
August 28
Yes, the grasshopper swarm in 1875 continued.
The cold spell in 2004 yielded a low temperature on this date of 42 degrees setting a record.
1968, lightning again reared its ugly head. One man was seriously injured while riding a roller coaster at Denver Amusement Park. An airline employee was injured by lightning while working on a plane at Stapleton International Airport. Also, lightning caused serious damage to a Denver house and minor damage to several others.
Also on this date…. In 2002 a thunderstorm produced ¾ inch hail in Parker and in 2005 lightning sparked a small fire near Jamestown.
NOAA says there is a greater chance for hurricanes in the coming months.
In their August update to hurricane season forecasts, experts at the National Oceanic and Atmospheric Administration (NOAA) have changed their predictions for the season and now expect a greater chance of hurricanes this season. They are now predicting an “above normal” season with 14 to 18 named storms – up from the 12 to 16 they predicted in May.
The forecasters now believe there is an 85 percent chance that this above normal trend will take place (up from 65 percent in May).
“Leading indicators for an above-normal season during 2008 include the continuing multi-decadal signal – atmospheric and oceanic conditions that have spawned increased hurricane activity since 1995 – and the lingering effects of La Niña,” said Gerry Bell, Ph.D. of NOAA’s Climate Prediction Center. “Some of these conditions include reduced wind shear, weaker trade winds, an active West African monsoon system, the winds coming off of Africa and warmer-than-average water in the Atlantic Ocean.”
The updated 2008 hurricane outlook.
Thus far in 2008 there have been five named storms and the most active hurricane period – August to October – is just now beginning. Will this prediction hold true? Unfortunateley forecasters have struggled in recent years with their predictions. Last year NOAA predicted 10 hurricanes and only six formed. The year prior, 2006, nine hurricanes were forecasted by NOAA but only five formed. In 2005, the year Hurricane Katrina devastated New Orleans in the worst U.S. natural disaster, the forecasts underestimated storm activity.
Weather, natural disasters & climate news and information.
It looks like the first part of next week we will return to more seasonal weather and temperatures into the 80’s.
