Special (1/14/2016) Alex became a hurricane on Thursday Jan 14, 2016 Update [Wednesday January 13, 2016 at 5 pm AST] Sub-Tropical Storm Alex has formed in the East Atlantic. As discussed below, Alex is only the second-known storm to form during the month of January in the 174-year database (1842-present). ➡︎ See also: Forecast #1 … Read more
December 2015 was unseasonably warm for Atlanta, Georgia. The temperature fell below freezing only one time, on December 19th when the low temperature was 29ºF. The day prior, on December 18th, the low was only 32ºF. In 2015, the average temperature (combined high and low) was 57.5ºF, which breaks the record previously set 126 years … Read more
2015 was Atlanta’s Warmest Christmas on Record Results of My Forecast Posted on December 23rd On December 23rd, I predicted that records would be tied or broken each day from Christmas Eve through December 27th (4 days in a row). As of 5 am, Sunday 12/27, the forecast has been a success. My median forecast … Read more
Christmas Week Forecast Page ➡︎ Heavy Rain Event & Possible Flooding: ● Forecast #1 Thu 12/24 ● Forecast #2 Fri 12/25 ➡︎ All Christmas Week Updates: ● #1 Sun 12/13 ● #2 Tues 12/15 ● #3 Sat 12/19 ● #4 Thurs 12/24 ● #5 Fri 12/25 First forecast is at the … Read more
Rainfall Records for DFW (Since Records Began) [year]: Rainfall so far this year DFW Records Summary: 2015 is the wettest year on record (rainfall in 2015) Wettest November on record The most rain ever recorded on any day in November (11/27/15) The greatest 2-day total ever recorded within the 215 days between September 23 and … Read more
Outcome Update #2 Posted Sunday 11/29/15 at Noon The rainfall configuration and amounts lined up very well with my forecasts leading up to this event (documented further down this page). Records were set, as predicted, and 2015 will go down as the wettest year on record. Check out our real-time rainfall tally to see how … Read more
How does the first freeze of 2015 compare with normal (climatology)? ❄️ The average first freeze at DFW is November 22. Therefore, this year’s freeze was right on schedule, based on the current 30-year average (1981-2010). Other Freeze Statistics for DFW: Average first freeze: November 22 Average last freeze: March 13 Earliest freeze on record: … Read more
The fluid dynamics associated with atmospheric disturbances cause the downstream air (ahead of the disturbance, before it arrives at a location) to rise, and the upstream air (behind the disturbance, i.e., after the disturbance has passed) to sink. If there is sufficient moisture in the area of rising air, clouds and precipitation may form. Necessary … Read more
This was a lot of fun for me. The Weather Channel featured me on their “Weather Geeks” show, which is hosted by my friend and colleague, Dr. Marshall Shepherd. My Favorite Photo I have over 30,000 photos in my library, and the first photo shown in the segment is my favorite. This was a historic … Read more
Imagine yourself as a cloud, happily floating over the surface of the Earth without a care in the world. As you drift across the sky, the millions of tiny water droplets and ice crystals that you are composed of brush against each other, causing a buildup of electric charges in your cloud body. The negative … Read more
Final Rainfall Amounts [Posted Saturday 10/31 at 1:25 pm] The NWS in Fort Worth prepared this graphic depicting storm total rainfall amounts. Using the legend, I drew the 2-inch line. Clearly, most of the area saw 2 to 4 inches, but there was an area of 4 to 7 inches in Tarrant, Dallas, Johnson, and … Read more
➡︎ Update History: Initial Forecast (Sunday 10/18) & Updates 2 through 5 | Update #6 | Update #7 Forecast Verification and Records Tied or Broken ◙ Record #1 [Broken] 2.58 inches of rain at DFW on Thursday 10/22 shattered the previous record for the date (2.19″) set in 1908. ◙ Record #2 [Broken] 3.55 inches … Read more
➡︎ Update History: Initial Forecast (Sunday 10/18) | Update #2 | Update #3 | Update #4 | Results/Records Broken Latest Forecasts (Starting at Update #6 on Friday 10/23) Continued Here Forecast Verification and Records Tied or Broken ◙ Record #1 [Broken] 2.58 inches of rain at DFW on Thursday 10/22 shattered the previous record … Read more
Atlanta’s biggest snowfall events of all time are listed in the table below. The most snow ever recorded on a single day in Atlanta was on January 23, 1940 when 8.3 inches fell. The top 10 snowstorms in Atlanta have a median accumulation of 4.2 inches. View the full list We often hear the cliche: … Read more
I love this animation. After spending years trying to explain these concepts, along comes high-resolution satellite images sewn together from a Lagrangian perspective to create a fast animation that actually shows the seasons changing as Earth tilts on its axis from equinox to solistice to equinox and so on. Credit: Simon Proud, researcher in the … Read more
The autumnal equinox occurs Sunday, September 22, 2024 at 7:43 AM, but the days and nights are not considered equal until Saturday, September 26th. This is because of the atmospheric refraction of sunlight. When a wave encounters a medium whose density differs from that through which the wave has been propagating, conservation of momentum and energy … Read more
A hurricane is the exact same meteorological phenomenon as a typhoon. The difference is simply a function of the storm’s location relative to the International Date Line (180ºW). A “hurricane” west of the International Date Line (IDL) is called a typhoon. The term is believed to have its origins in Sinitic, one of the Chinese … Read more
On August 29, 2015, for the first time on record, three *major* hurricanes were active simultaneously in the central/eastern Pacific (east of the International Date Line, 180ºW). A major hurricane is defined as a category 3 or higher. Yet another record was set at 10 pm CDT. 8 pm CDT 8/29: Three Major Hurricanes Set … Read more
On this, the -year anniversary of Hurricane Katrina’s final landfall east of New Orleans, I wanted to share some graphics and the very rare, dire warning issued the National Weather Service in Slidell, Louisiana that likely saved many, many lives. Radar Loop at Landfall Satellite Loop at Landfall Location of the NWS Brief … Read more
Prior to the advent of weather satellites and aircraft reconnaissance of tropical cyclones during the mid-20th century, the loss of life due to unexpected, landfalling hurricanes was tremendous. In 2015, hurricane forecasting continues to improve thanks to ongoing upgrades in observational technology (aircraft, dropsondes, tail radar, etc.), computational resources, improved numerical prediction models (model resolution, … Read more
Summary & Forecast Verification [Thursday 8/20/15 8 pm] ***Today Among Our Coldest August Days on Record*** A few days ago, I predicted that our strongest cold front in 3 months would move through North Texas (below). The forecast worked out perfectly (and to the contrary of the armchair meteorologists who declared otherwise on the day … Read more
Trends In The Ratio Of Damage To Deaths Caused By United States Land-Falling Hurricanes 24th AMS Conference on Hurricanes and Tropical Meteorology (2000) Chris C. Robbins and James Gross National Hurricane Center, Miami, Florida We have estimated that, if the pre-reconnaissance trend continued at the time of Hurricane Andrew, approximately 4,354 deaths may have … Read more
A Climatology Of Rapidly Intensifying Tropical Cyclones In The North Atlantic Basin, 1975-2000 25th AMS Conference on Hurricanes and Tropical Meteorology (2002) Chris C. Robbins and Stacy R. Stewart National Hurricane Center, Miami, Florida 1. Introduction Rapidly intensifying tropical cyclones pose a significant forecast problem for operational meteorologists. Unfortunately, the climatological nature of such … Read more
I want to kick off this piece with a discussion of Tropical Depression Bill’s intensification over Missouri, hundreds of miles inland. ➡ Click here to skip to the North Texas impacts to see how much rain fell at DFW and what the peak winds were as Bill passed across the area. At 4 p.m. CDT Friday, … Read more
This post is a carryover from the previous post that contained three days worth of forecast updates leading up to the formation of Tropical Storm Bill. In an effort to improve readability, I thought it would be best to create a new post given that T. S. Bill will soon make landfall and subsequently move … Read more
Mesocyclone-Induced Downbursts Associated With The Landfall Of Hurricane Irene (1999) Over S. FL 24th AMS Conference on Hurricanes and Tropical Meteorology Stacy R. Stewart and Chris C. Robbins Tropical Prediction Center, Miami, Florida 1. Introduction This paper examines the occurrence of multiple damaging downbursts or “miniswirls” with the passage of Hurricane Irene across South … Read more
May 2015 was the wettest month ever recorded in the United States since record keeping began 121 years ago according to the National Climatic Data Center (NCDC). The main contributing factor to the nation’s “wettest-May” was the incredible rainfall totals across the Central United States. Meteorologist Chris Robbins posted that May 2015 was the wettest … Read more
Latest Forecast ➡ A new post about Tropical Storm Bill was started to help improve readability. All previous forecast updates in the three days leading up to Bill’s formation are archived below, in the order that they were written. ➡ Final Event Recap: As predicted, peak wind gusts of 50 mph and greater, and record … Read more
A follower asked, “if the water cycle is real, how can there be water shortages?” In light of the recent drought in Texas, which ultimately ended with the historic rainfall during the month of May 2015, and the ongoing devastating drought in California, I thought I would make this brief post. What is the Water … Read more
May 2015 was an exhausting month for forecasters in Oklahoma and Texas. One storm system after another brought enormous rainfall and significant flooding to many areas. I will try to post some dynamics/thermodynamics analyses or a general recap of each individual storm system in a future addendum to this post. For now, I wanted to … Read more