Weather

cumulonimbus pileus
September 4

Crazy Extremes Facing Denver – Did Harsh NWS Language Save Lives with “Laura”?

  Moderately Cool Third Week of September. Temperatures over the northern tier of the USA will be cooler than average 2 weeks out, if you buy the GFS solution above. We’ll see more warm fronts, more 70s and 80s into late September, but while much of the south and west sizzles Minnesotans will be reaching for sweatshirts much of the next 2 weeks. Definition of a Cold Front. I’m sure this has happened before, but I can’t remember anything quite this drastic in recent years; a nearly 65 degree drop in the span of 2-3 days? ECMWF (above) for Denver...

Hurricane Laura ISS
September 3

Dangerous Hurricane Laura Approaches Gulf Coast – Higher Resolution Tornado Simulations

Hurricane Laura Threatens Gulf Coast “The first rule of hurricane coverage is that every broadcast must begin with palm trees bending in the wind” wrote author Carl Hiaasen. True. And frantic TV reporters hunkered down on the beach. Hurricane Laura is forecast to come ashore late tonight, perilously close to Houston. The storm is passing over warm water, jet fuel for hurricanes. It may roar ashore with 115 mph winds and a basketball-hoop-high storm surge of over 10 feet. You can’t blame Houstonians for being paranoid. 3 years ago “Harvey” dropped 60 inches of rain, leaving behind $125 billion in...

hurricane Humberto
September 3

Tracking “Omar” and “Nana” – Will We Run Out of Hurricane Names in 2020?

Like climate change, coronavirus often doesn’t hit home until it…hits home. One of my nieces at a big eastern university caught Covid-19 (she’s fine). My 91 year old mother-in-law, Josephine, also caught the virus and recovered. Her grandkids call her “Nana”, which is ironic. So far this year in the Atlantic we’ve had a Tropical Storm Josephine and a Tropical Storm Nana. 65-70 percent of hurricane season is ahead of us, with only 6 names remaining on the list. At this rate we may have to start over with the Greek alphabet. The last time that happened was 2005, the...

aerisweather-globe-hurricane
August 26

Tropical Storm Isaias Threatens Florida and Carolinas – Baghdad Hits a Record 125F

Tracking “Isaias” “Nature has a myriad of weapons to combat human arrogance” wrote film director Wayne Gerard Trotman. Tell me about it. From Texas-size hurricanes to invisible, microscopic viruses. We delude ourselves into thinking we’re in charge – but nature always bats last. “Isaias” is forecast to remain a tropical storm as it churns up the east coast of Florida; hurricane-force gusts are possible Saturday, with moderate coastal erosion and inland flooding from Florida to the Carolinas. Isaias is the earliest 9th storm on record. This may be an intense hurricane season, made much worse by the pandemic. August: Nearly...

mosquito biting human
August 25

Tropical Trouble Brewing for Florida and the Carolinas

Extended Outlook Calls for More Mosquitoes. “When the facts change, I change my mind. What do you do sir?” economist John Maynard Keynes dryly observed. We have the freedom to change our minds. I have more respect for people who change their minds based on new evidence, rather than digging in their heels and cherry-picking data to support an opinion. Based on a wealth of evidence, the climate is warming, and new research shows mosquito season at MSP has grown from 114 days in the 1980s to 120 days in the 2010s. If anyone asks (doubtful) mosquitoes survive best between...

August 25

Dangerous Hurricane Laura Threatens Coastal Texas and Louisiana – Tracking Smoke from Western Wildfires

Briefing: Issued Monday morning, August 24th, 2020: A long week of weather is ahead along the northern/northwestern Gulf Coast as both Tropical Storm Laura (located south of central Cuba this morning) and Tropical Storm Marco (in the northern Gulf of Mexico) threaten the region. Marco is expected to either scrape or make landfall across southern Louisiana today into Tuesday, weakening while it does so. However, it will still bring the threat of damaging winds, storm surge, and flooding rains along with it to the northern Gulf Coast. Laura will continue to move near/across Cuba today and tonight. By early Tuesday...

hurricane Florence from space
August 24

Tropical System Threatens Florida – Pandemic Complicates Hurricane Evacuation Plans

Hurricane Evacuations During a Pandemic? How on Earth do you safely evacuate tens or even hundreds of thousands of people inland, during the Age of Covid-19? Great question. We may soon find out. “Hanna” was a dry run in south Texas and “Douglas” narrowly missed Hawaii. Now there’s a new tropical system which may, in theory, impact Florida this weekend. Giving people more time to prepare, opening up hotels, in addition to schools, to evacuees, and encouraging people who’s homes are up to code to stay put may help, but during a chaotic rush inland, social distancing and mask hygiene...

storm-July-8-2018-Mark-Anderson_storm
August 13

Difficulties of Predicting Severe Thunderstorms – “Josephine” Forms – La Nina Brewing

Severe Storm Specifics In Advance? Good Luck Cue the theme from “Mission Impossible”. One of the few challenges greater than predicting how many inches of snow will pile up in YOUR yard is when and where severe storms may bubble up. Once they’ve formed we can track dangerous storms, leveraging a network of 160 “NEXRAD” Doppler radar sites operated by The National Weather Service. New high-resolution models, including NOAA’s HRRR (High-Resolution Rapid Refresh) update every hour at 3km resolution. Meteorologists can give a few hours lead-time, but predicting which towns will be hit hard vs. other towns that experience a...

August 13

USA Heat Wave Lingers Into Late August – Tornado Alley No-Show in 2020

  Extended Outlook: Simmering Heat Into Late August. GFS guidance continues to plant a giant heat-pump high pressure bubble over much of the USA the last week of August, meaning more 90s and excessive heat indices. That should mean 80s, even a shot at a few 90s, for Minnesota and the Upper Midwest. What is a Derecho? Dr. Marshall Shepherd has a good explainer at Forbes; here’s an excerpt: “…NOAA defines a derecho as, “(pronounced similar to “deh-REY-cho” in English, or pronounced phonetically as “”) a widespread, long-lived wind storm.” They are typically associated with organized bands of rapidly moving...

storm-derecho_plains
August 12

August 11: Derecho Climatology – Growing Risk of “Josephine”?

What Exactly Is a Derecho, Paul? Tracking CBs on WSR-88D Doppler? ECMWF, AWIPS, now derecho? Meteorologists LOVE to toss around funky terms. The derecho that blasted Iowa with 115 mph wind gusts Monday tracked 750 miles, from North Dakota to Indiana. This sprawling boomerang-shaped line of fast moving storms produced extensive straight-line wind damage, comparable to an EF-1 tornado. Derechos are rare, but climatology from SPC (sorry, the Storm Prediction Center) suggests parts of central Minnesota see a derecho every year. Hurricane-force winds, but only lasting for 30 to to 45 minutes. Yikes. What is a Derecho? Dr. Marshall Shepherd...