NATIONAL STORM SUMMARY

SEPTEMBER 2021

Aug. 29-Sep. 4: Hurricane Ida cut a destructive swath from the central Gulf Coast region into the Northeast, spending parts of 5 days (August 29 – September 2) inland. Initially, primary hurricane impacts included high winds and a coastal storm surge, which resulted in extensive damage and power outages across southeastern Louisiana. Once inland, the focus turned to freshwater flooding and heavy rain, which totaled 4 inches or more in eastern Louisiana and parts of Alabama, Mississippi, and western Florida. Despite significant weakening (to a tropical depression after spending a little more than 24 hours inland), Ida sparked catastrophic mid-Atlantic flooding on September 1-2, as the remnant circulation merged with a cold front. Totals of 4 to 8 inches or more fell from southeastern Pennsylvania into southern New York, accompanied by locally severe thunderstorms and isolated tornadoes.

 

Heavy rain also fell across portions of the Plains, Southwest, and western Corn Belt, due to the interaction between the monsoon circulation and a cold front. Some of the heaviest rain, locally 4 inches or more, fell in eastern Kansas and environs.

 

As Hurricane Ida roared ashore near Port Fourchon, LA, on August 29, a ship in port recorded a gust to 172 mph. Several other coastal Louisiana wind gusts exceeded 120 mph, including a report of 122 mph at a University of Florida meso-network tower installed near Galliano, LA. Farther inland, wind gusts were clocked to 90 mph in New Orleans, LA, and 68 mph in Gulfport, MS. On Lake Borgne, LA, at Chef Menteur Pass, the peak water level on August 29 rose to within 2.37 feet of the record set during Hurricane Betsy on September 10, 1965. On Breton Sound at Black Bay, near Stone Island, LA, there was a 10.39-foot water level rise reported in just over 12 hours, ending at 10:30 am CDT on August 29. Water pushing inland from the Gulf of Mexico led to the sixth-highest crest on record along the Mississippi River at Venice, LA. Ida’s August 29 crest in Venice was 2.75 feet lower than the record associated with Hurricane Camille on August 17, 1969—and was also lower than water levels observed with Georges (1998), Betsy (1965), Ida (2009), and Gustav (2008). Farther inland, the Biloxi River near Lyman, MS, crested 5.24 feet above flood stage on August 31, marking the highest level in that location since April 28, 2016. In Mobile, AL, the last 3 days of August featured 9.37 inches of rain. Record-setting rainfall totals for August 31 included 2.21 inches in Frankfort, KY, and 2.18 inches in Chattanooga, TN. Separately, a cold front crossing the Midwest contributed to a daily-record sum (2.56 inches on August 31) in Moline, IL. Ida’s most impressive rain occurred in early September across the Northeast. In fact, September 1 was the wettest day on record in Newark, NJ (8.41 inches), and New York’s LaGuardia Airport (6.80 inches). Previous records had been 6.73 inches on November 8, 1977, and 6.69 inches on April 15, 2007, respectively. September 1 was the third-wettest day on record in Harrisburg, PA (6.64 inches), and Poughkeepsie, NY (5.57 inches). With 7.13 inches on the 1st, New York’s Central Park experienced its wettest day since April 15, 2007, when 7.57 inches fell—and wettest September day since 1882, when 8.28 inches fell on the 23rd. Daily-record totals in the 4- to 6- inch range on September 1 occurred in Bridgeport, CT (5.77 inches); Trenton, NJ (5.60 inches); Mount Pocono, PA (5.56 inches); Scranton, PA (5.09 inches); Reading, PA (4.95 inches); Allentown, PA (4.15 inches); Baltimore, MD (4.13 inches); and Hartford, CT (4.07 inches). In the wake of Northeastern downpours, record flooding engulfed several river basins across Pennsylvania and New Jersey on September 1-2; for more details, see the flood summary on page 8. In addition, the remnants of Ida spawned more than a dozen Northeastern tornadoes, mainly on September 1. On that date, a thunderstorm in Montgomery County, PA, resulted in the nation’s first tornado-related fatality since April 10. Meanwhile, locally heavy showers stretched from the Southwest to the Midwest, with some rain falling as far west as southern California. Record-setting amounts for August 31 included 1.34 inches in Norfolk, NE, and 0.32 inch in Alpine, CA. On September 1 in Arizona, record-setting rainfall amounts reached 1.12 inches in Safford and 0.44 inches in Nogales. With 2.30 inches, Alliance, NE, also netted a daily-record sum for the 1st. On September 2 in South Dakota, Sisseton (1.92 inches), Huron (1.84 inches), and Watertown (1.57 inches) set daily rainfall records. At week’s end, a cold front sparked additional Midwestern rainfall; in Illinois, Carbondale (3.00 inches) and Springfield (2.36 inches) collected record-breaking amounts for September 4.

5-11: Rain was observed, however, in several regions, including much of the East. Some of the heaviest rain (locally 4 inches or more) fell in northern New England, chipping away at lingering, long-term drought. Locally heavy showers also dotted the lower Southeast, including Florida’s peninsula. Elsewhere, late-week rain briefly dampened some of the driest areas of the West, temporarily aiding wildfire containment efforts. On September 10, the heaviest rain in months—up to an inch—fell in parts of northern California and the interior Northwest. 

 

late in the week, scattered to widespread showers were mostly limited to the South, East, and lower Midwest. Daily record totals were set in a few locations, including Houghton Lake, MI (1.62 inches on September 7), and Louisville, KY (1.10 inches). Heavier rain fell in northern New England, where Bangor, ME, measured 3.34 inches on September 9-10. Meanwhile, rainfall across the lower Southeast was enhanced by the arrival of minimal Tropical Storm Mindy, which officially made landfall on St. Vincent Island, FL, on September 8 at 8:15 pm CDT. Mindy’s sustained winds were briefly near 45 mph, followed by weakening the following day as the remnant circulation moved northeastward across northern Florida and southeastern Georgia. On September 8, Tallahassee, FL, received 2.80 inches of rain and clocked a peak gust to 40 mph. Elsewhere in Florida on the 8th, Apalachicola noted 2.10 inches of rain and had a gust to 42 mph. Toward week’s end, beneficial rain overspread northern California and the Northwest. With 0.37 inch on September 10, Redding, CA, experienced its wettest day since April 25, when 0.39 inch fell. Record-setting rainfall totals for September 10 included 0.63 inch in Ephrata, WA; 0.61 inch in Redmond, OR; and 0.26 inch in Red Bluff, CA.

12-18: Hurricane Nicholas made landfall in Texas on the Matagorda Peninsula. Nicholas, only briefly a hurricane, moved ashore around 12:30 am CDT on September 14, with sustained winds near 75 mph. Shortly before landfall, an observation site at Matagorda Bay, TX, clocked a wind gust to 95 mph. The remnants of Nicholas continued to produce locally heavy showers for the remainder of the week, even after the circulation center decayed over Louisiana on September 17.  

September 12-14 rainfall in Texas associated with Hurricane Nicholas totaled 7.91 inches in League City; 5.70 inches in Pearland; 4.33 inches in Galveston; and 3.95 inches at Houston’s Hobby Airport. On September 13, easterly wind gusts were clocked to 77 mph in Palacios, 62 mph in Galveston, and 60 mph in Bay City. Early the following day, Texas gusts reached 60 mph in Pearland and 58 mph at Hobby Airport. Record-setting rainfall amounts for September 14 included 5.20 inches in Beaumont-Port Arthur, TX, and 4.03 inches in Lafayette, LA. September 12-15 totals in those locations were 7.07 and 5.53 inches, respectively. Unofficially, Bunkie, LA, received 10.60 inches in a 24-hour period on September 14-15. Meanwhile, a separate area of rain crossing the lower Midwest and interior Southeast resulted in a daily-record sum (2.59 inches on September 15) in Bowling Green, KY. Parts of the Southeast also continued to receive heavy showers, with Hattiesburg, MS (3.02 inches), and Augusta, GA (2.77 inches), netting daily-record totals for September 16. Additional Southeastern rain on the 17th led to daily-record amounts in Montgomery, AL (1.90 inches), and Crossville, TN (1.15 inches). Late in the week, highly beneficial precipitation overspread the Northwest. In Oregon, record-setting totals for September 18 reached 1.31 inches in Portland and 1.13 inches in Salem. With a 0.42-inch sum, Spokane, WA, also collected a record-setting total for September 18. Portland’s 3-day (September 17-19) rainfall reached 2.52 inches.

19-25: Locally heavy showers lingered in the Southeast, even after the remnants of Hurricane Nicholas decayed on September 17 over northern Louisiana. Eventually, the tropical moisture was swept away by a cold front, which was also responsible for heavy rain from the lower Great Lakes region into the Northeast. 

 

Lingering Northwestern showers ended on September 19; following a daily-record sum of 1.14 inches in Portland, OR, on that date, Portland’s September 17-19 rainfall totaled 2.52 inches. Meanwhile, locally heavy showers dotted the South and East. Sanford, FL, was deluged with 5.17 inches of rain on September 19, marking the wettest day in that location since September 10, 2017. Daily-record rainfall amounts for the 19th included 3.31 inches in Huntsville, AL, and 2.26 inches in Chattanooga, TN. On the 20th, a 6.66-inch total in Savannah, GA, represented the wettest September day in that city since September 4, 1979, when 6.79 inches fell. Meanwhile, showers and thunderstorms developed across the upper Midwest, where International Falls, MN (2.02 inches on September 20), reported its first day with a least 2 inches of rain since July 17, 2019. Even with the rain, International Falls’ January 1 – September 25 precipitation stood at 14.39 inches, just 71 percent of normal. As the week progressed, rain spread into other areas of the Midwest. On September 21, Carbondale, IL, collected a daily-record sum of 2.89 inches. The following day in Indiana, record-setting amounts for September 22 included 2.11 inches in Fort Wayne and 2.07 inches in Indianapolis. In the lower Great Lakes region, 4-day (September 20-23) rainfall totals included 4.83 inches in Toledo, OH, and 4.47 inches in Detroit, MI. Meanwhile, heavy rain also overspread the middle and northern Atlantic States. Blacksburg, VA, measured 3.00 inches on September 21, a record for the date. Elsewhere in the midAtlantic, record-setting rainfall totals for the 22nd reached 4.31 inches in Wilmington, NC, and 2.11 inches in Roanoke, VA. Wilmington’s 4-day (September 20-23) rainfall climbed to 9.43 inches. Rain swept into the Northeast by September 23, when daily-record totals included 2.83 inches in Williamsport, PA, and 1.69 inches in Rochester, NY. Elsewhere in New York, recordsetting amounts for the 24th reached 1.52 inches in Glens Falls and 1.46 inches in Plattsburgh. Bangor, ME, received 4.19 inches of rain from September 24-26. In contrast, the 8-week (56- day) period from August 1 – September 25 featured rainfall totaling just 0.88 inch (13 percent of normal) in Tulsa, OK. Similarly, Wichita Falls, TX, received no measurable rain in the 37-day period from August 20 – September 25.

26-30: In western Washington, record-setting rainfall totals for September 26 reached 2.14 inches in Quillayute and 1.67 inches in Hoquiam. Crescent City, CA, netted a daily-record total of 1.68 inches on September 27. Some heavy rain also persisted in Maine, where Bangor’s 2.28-inch sum on the 26th boosted its September 24-26 total to 4.19 inches. Meanwhile, the arrival of heavy showers in the western Gulf Coast region led to a record-setting amount for September 28 in Lake Charles, LA, where 3.51 inches fell. During the mid- to late-week period, rain developed across portions of the Plains and Rockies, although amounts were variable. On September 29, daily-record totals included 1.22 inches in North Platte, NE, and 0.50 inch in Casper, WY. However, even with the late-September rainfall, monthly totals were less than one-half inch in Oklahoma City, OK (0.46 inch, or 12 percent of normal); Wichita Falls, TX (0.34 inch, or 11 percent); Havre, MT (0.05 inch, or 5 percent); and Glasgow, MT (0.03 inch, or 3 percent). For Havre, it was the second-driest September on record, behind only 0.04 inch in 1990. For Glasgow, it was the driest September since 2012, when 0.02 inch fell. Elsewhere, late-week precipitation was particularly heavy from the western Gulf Coast region into the mid-South. In North Little Rock, AR, where records have been kept for more than 45 years, the 2nd was the wettest October day on record. North Little Rock’s October 2 total of 5.25 inches clipped the mark of 5.23 inches, originally set on October 29, 2009. It was also North Little Rock’s wettest day since November 18, 1988, when 7.01 inches fell. Meanwhile, Deep South Texas was inundated by heavy rain on October 1, when totals reached 8.09 inches in Brownsville and 6.11 inches in Harlingen. For Brownsville, it was the wettest day since October 4, 1996, when 9.09 inches fell. Brownsville’s 2-day (September 30 – October 1) rainfall totaled 10.42 inches. In contrast, parts of California completed their driest water year on record. For example, precipitation from October 1, 2020 – September 30, 2021, totaled just 6.61 inches (36 percent of normal) in Sacramento and 14.24 inches (42 percent) in Redding. Previous records had been 6.62 inches (in 1976-77) in Sacramento and 19.38 inches (in 1990- 91) in Redding.

Jim G. Munley, jr.
http://www.jimmunleywx.com