Weather Anxiety: Why Does the Forecast Change?
By Paul Douglas
It looks like meteorological bait-and-switch. On a Wednesday you check the paper or web site (or favorite app) and the weekend forecast looks great. Look at all those sun symbols! Cue Jimmy Buffet tunes in your head. But by Friday those smiling sun symbols mutate into ominous raindrops and lightning bolts. Say what?
Here's the deal: the forecast changes as new data comes in. Observations from satellites, weather balloons and airports fuel weather models that allow us to look out a week. Junk-in, junk-out. The closer you get to the event the more reliable the data that fuels the models we look at.
Global ECMWF (European) and GFS models run twice a day; NOAA's NAM model updates 4 times daily - and we make changes to the 7-Day.
We dry out today but models bring more T-showers into Minnesota Wednesday into Sunday. It won't be a continuous rain, but unusually chilly air aloft keeps the atmosphere in a showery mood later this week. Enjoy a run of comfortable 70s because I see more 80s and a few steamy 90s returning later this month. Do NOT write off the summer of '17 just yet.
Extended Twin Cities Forecast
MONDAY: Lukewarm sun, perfect. High 80. Low 60. Chance of precipitation 10%. Wind N 3-8 mph.
TUESDAY: Blue sky, as good as it gets. High 81. Low 62. Chance of precipitation 10%. Wind SW 7-12 mph.
WEDNESDAY: Sunny start, late PM T-storm. High 80. Low 63. Chance of precipitation 40%. Wind S 7-12 mph.
THURSDAY: Humid, more showers & T-storms. High 76. Low 62. Chance of precipitation 60%. Wind S 5-10 mph.
FRIDAY: Sunny breaks. Drying out a bit. High 78. Low 61. Chance of precipitation 10%. Wind NE 7-12 mph.
SATURDAY: AM sun, few PM storms possible. High 76. Low 60. Chance of precipitation 50%. Wind E 7-12 mph.
SUNDAY: Have a Plan B. Showers in the area. High 72. Low 61. Chance of precipitation 60%. Wind E 10-15 mph.
This Day in Weather History
1968: 7.09 inches of rain falls at Mankato. 1,200 homes are damaged. Highways 169 and 22 are blocked by mudslides.
1955: The climate record of George W. Richards of Maple Plain ends. He recorded weather data with lively notations on phenology and weather events. He began taking observations when he was eleven in 1883. He continued to take observations for 72 years, with 66 years as a National Weather Service Cooperator.
1896: The final day of a massive heat wave brings highs of 104 to Le Sueur and Mazeppa.
1863: A Forest City observer sees what he calls a 'perfect tornado.' He noted that it 'drove principally from west to east and lasted about one half hour.'
Average Temperatures & Precipitation for Minneapolis
Average High: 82F (Record: 98F set in 2001)
Average Low: 63F (Record: 45F set in 1972)
Average Precipitation: 0.15" (Record: 2.29" set in 1984)
Sunrise/Sunset Times for Minneapolis
Sunrise: 6:05 AM
Sunset: 8:31 PM
*Length Of Day: 14 hours, 25 minutes and 12 seconds
*Daylight Lost Since Yesterday: ~2 minute and 35 seconds
*Next Sunrise At/After 6:30 PM: August 28th (6:30 AM)
*Next Sunset At/Before 8:30 PM: August 8th (8:29 PM)
Minnesota Weather Outlook
National Weather Outlook
Many Rain Delays At SunTrust Park - Why?
Another Wet, Warm Month Across The U.S. In July
Global Warming and Monsoon Season
The Top Coal-Producing State Is Turning To Wind Energy
Super-Colossal Wind Turbines?
Ready for even bigger wind turbines? They may be coming soon. More from NBC News: "When it comes to building things, Eric Loth has his head in the clouds. This engineering professor at the University of Virginia wants to construct a wind turbine standing more than five times higher than the Statue of Liberty, with rotor blades longer than the Washington Monument is tall. Not only that, the 1,650-foot-high mega-turbine would change along with the weather, bending its blades gracefully to cope with hurricane-strength winds. And all of this would happen dozens of miles out at sea."
Thanks for checking in and have a great Monday! Don't forget to follow me on Twitter (@dkayserwx) and like me on Facebook (Meteorologist D.J. Kayser)!
- D.J. Kayser