September 1: Go Away, Harvey

The National Weather Service office in Nashville has confirmed TWO tornadoes from yesterday and last night – one in the Bordeaux area, another near Mt. Pleasant in Maury county.  No word yet on the Fujita-scale rating on the Maury county twister, but the Bordeaux tornado has been rated EF-1, with winds estimated at 95mph and a track length of 0.7 miles — it was on the ground for only two minutes.  NWS is hoping to release the official statement for the Mt. Pleasant tornado later today, but it takes time to put those reports together.  Also, it’s still possible that more damage could be found, so the number of confirmed tornadoes could still climb.

The remnants of Harvey are still producing light to moderate showers, which will continue much of the night and gradually shift eastward.  The HRRR model’s radar simulation through 7:00am has a good handle on that trend:

No additional flooding problems are anticipated, but there are plenty of rivers and creeks that are still near or above flood stage, most notably the Red, Cumberland, Duck and Harpeth Rivers:

PLEASE NOTE — those images are current as of 3:40pm Friday.  Updated river information can always be found on the National Weather Service’s web site.

Temperatures will gradually drop to the upper 50s by early Saturday morning:

At that point, the best chance of showers will be east of I-65, and the showers will continue creeping farther east throughout the day — we should even see some sunshine along and west of I-65 by Saturday afternoon!  That sunshine will push high temperatures up to the mid to upper 70s…except in the northeastern corner of the Midstate, where the lingering clouds will keep you in the 60s:

Nice weather for the rest of Labor Day weekend — partly cloudy and warm, with highs in the low to mid 80s Sunday, and the mid to upper 80s Monday.  Another chance of rain heads our way Tuesday, but it won’t be nearly as heavy and it won’t last nearly as long as what we just went through:

We’re still keeping an eye on Hurricane Irma in the Atlantic Ocean as well:

Yesterday I was concerned that Irma’s path would help to “clog up” our weather pattern in the Midstate, forcing Tuesday’s rain to linger Wednesday and Thursday.  I’m not as concerned about that today, which is why I’ve left the forecast dry for Thursday and Friday.  The National Hurricane Center’s forecast path carries Irma toward the island chain (The Leeward and Windward Islands) that marks the entrance to the Caribbean Sea:

Beyond that, both the European and American long-range forecast models bend the storm toward the East Coast of the United States late next week and the following weekend — they of course disagree on the details of how fast that bend occurs and if Irma will touch the mainland U.S.  It’s WAAAAAAAY too soon for me to post those forecast images yet, because so much can change — but it’s something to keep in mind if you have post-Labor Day travel plans.

About paulheggen33

Morning meteorologist for WNCN-TV in Raleigh.
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1 Response to September 1: Go Away, Harvey

  1. Fred says:

    As Daphne expressed it: What a night (and a month), indeed. With the record-breaking 2.91 inches of rain on the 31st (former maximum rainfall for the date was 2.27″, set back in 1944) August 2017 became the 3rd-wettest month of its name, and the total of 8.32 ” is the most since 1923, when Nashville had its wettest August ever (9.60″). Between 1976 and 2017 no August even reached the 7″ mark, the longest such streak for any month. The epic Hot streak, finally, came to an end, as Nashville had its first month of below average temperature since January 2016. At 77.7 degrees, exactly 1 degree below the norm, it was the 56th coolest August and, also, the month with the greatest temperature deficit since August 2015, which averaged 77.2.
    Most months of above-average temperature

    18: February 2016 – July 2017
    12: May 1881 – April 1882
    11: May 2007 – March 2008
    10: May 1998 – February 1999
    9: November 2011 – July 2012

    It’s worth noting that the top 5 is comprised of fairly recent years, with the exception of the previous record-holder. Does this mean that the law of averages kicks in and there’ll be a year-long stretch of below-average temps? Most likely, no, because we’re dealing with an unbalanced system (i.e. global warming, the term the media’s flogged to near death). Two other streaks were snapped as well. For the first time since 2003, Nashville’s NWS office issued tornado warnings in the month of August, the longest for any month. Furthermore, their total (10) was just one shy of the combined total from the previous 5 (!) Augusts (1992, 1997, 1999, 2001, 2003) that had some tornadic activity.

    Here’s a chart to illustrate this:

    https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=171&_l=on&opt=wfo&station=OHX&state=TN&phenomena=TO&significance=W&dpi=100&_fmt=png

    We had the first August tornadoes in the vicinity of Nashville since 1999, and the first ever tornado in Davidson county (near Bordeaux area) during the month of August, as it occurred shortly before midnight. Fortunately, there were neither injuries nor fatalities, and the reported damage was not great. August and July are the only two months in Middle TN when no tornado-related fatalities have ever been reported, and the current month has the fewest number of documented tornadoes (9), which represents slightly over 1.2% of the Middle TN’s recorded total. The only September twister with known casualties occurred in 1939, on the 4th, in White county, that resulted in 1 fatality and 6 injuries.
    The preceding month was, also, unusually cloudy, its sunrise-sunset sky cover value of 194 (out of the maximum possible 310, translating to an average of 63% of the sky being covered), surpassing that of August 2013 (192) for the cloudiest month of its name in 21st century. It may well be the cloudiest August since 1992, the all-time leader in that category (218), which had a single fair day hopelessly outnumbered by 15 cloudy ones. August is, typically, the month when the overcast conditions are at the minimum in Nashville, but there was way more than the fair share of gray. Additionally, on the morning of the 5th, when the temperature fell to 58, Nashville tied the lowest temperature for the date, previously observed in 1912 and 1974. At 78.5 degrees the climatological summer of 2017 was tied with 1978 and 1986 as the 52nd-warmest and 10th-wettest (16.58″) on record. Finally, here are two more charts indicating the “summer misery indices”, which measure the total number of hours of temperatures >=90 and dew point values at or above 70 degrees:

    https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=159&_l=on&network=TN_ASOS&zstation=BNA&var=tmpf&dir=aoa&thres=90&month=summer&year=2017&dpi=100&_fmt=png

    https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=159&_l=on&network=TN_ASOS&zstation=BNA&var=dwpf&dir=aoa&thres=70&month=summer&year=2017&dpi=100&_fmt=png

    So, in conclusion, it was a pretty hot and humid summer, overall.

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