Monday, January 27, 2020

Near average January weather ahead, with a bit of a drying trend?

Here is some welcome news on a Monday in late January:

(View tweet here if it's not visible above.)

The month has been wet so far, continuing a trend from, well, the last 2 years... Total rainfall has topped six inches for the month with barely more than a couple of dry days between each new bout of rain. We've got one more of those systems to deal with early this week, then it appears we may get a chance to dry out for a minute. (Though that doesn't necessarily mean days of sunshine and rainbows... it is January after all!)

Today and Tuesday

Weak high pressure ridging into the area is bringing us one of the warmer days we've had lately as sunshine this afternoon allows temperatures to climb into the the upper 50s. Should be a nice evening for a walk as long as you grab a jacket! The next low pressure system moving along the southern U.S. atmospheric railroad track arrives Tuesday night, and it'll be moving slowly. Tuesday will be back to mostly cloudy, though most of the daylight hours should be dry with highs again in the mid 50s.

Another rain-maker

Light rain arrives around the time of the homeward-bound rush hour. Look for highs in the mid 50s. Steadier (though light) rain continues Tuesday night as the mercury drops to near 40. Or, "not quite cold enough," and another opportunity wasted, according to snow-lovers. Lingering light rain or drizzle continues Wednesday on the back side of the departing system. It'll be a chilly, wet day as wind shifts to the north and temperatures remain in the 40s. Warm rain coats and waterproof gloves might be in order.

The high-res NAM3 model shows the next rain-maker moving through the Mid-South Tuesday night and Wednesday (loop from 6am Tuesday to 6pm Wednesday). Precipitation should not be heavy, but it stays just warm enough near the TN/MS line to keep the wintry precipitation to our north. (Graphic: WeatherBell)

The European model ensemble (basically, 51 slightly different runs of the Euro model) gives the Memphis area an average of about 0.20" of rain through Wednesday. No downpours, deluges, or washouts expected! (WeatherBell)

Week's end into the weekend

Thursday remains cool (mid 30s for lows to mid 40s for highs) with some high clouds still streaming overhead, but we start a new dry streak that day. How long does it last? Models are not unified in their "dryness index" as we head into the weekend, so updates to this forecast are possible, but it appears that we could have very low, maybe no, rain chances right into early next week as temperatures begin to warm a bit. By Sunday and Monday, I expect we'll see numbers closer to 60 degrees than 50 for highs as we roll into February and Groundhog's Day!


Recapping, and a longer look ahead

So to recap - a nice afternoon today, cooling trend with more wetness Tuesday night into Wednesday, then warming slowly back up with meh rain chances Friday/Saturday. No thunder, or snow. The 8-14 day outlook for next week calls for slightly above average temperatures and near average precipitation. NOAA's outlook for the month of February leans a bit cooler than average though. Winter is not over yet!


The Climate Prediction Center temperature outlook for next week indicates slightly above average temperatures.  (Graphic: Pivotal Weather)

The Climate Prediction Center precipitation outlook for next week indicates near average rainfall.  (Graphic: Pivotal Weather)


The Climate Prediction Center temperature outlook for Breviary shows areas from Memphis north in a cooler than average pattern. (Graphic: Pivotal Weather)

Erik Proseus
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Sunday, January 19, 2020

Memphis, TN Annual Climate Summary for 2019

2019 Annual Recap

Memphis weather in the year 2019 will be remembered for some very wet months that led to one of the rainiest years on record, as well as fairly large temperatures swings month-to-month. Overall the year ended in the upper echelon of warm years with a 0.4 degree departure from average. Precipitation-wise, eight of the twelve months of 2019 were above average, three by more than four inches and one of those (October) setting a new monthly record. In sum, the year ended fourth wettest on record.


Month-by-month recap

The precipitation anomaly for the year started in month #1 as January recorded about 3/4" of rain above average. Temperatures also averaged a bit above normal. January also featured the only measurable snowfall for 2019, 0.2" on the 19th. The trend was more pronounced in February with warm and wet weather continuing. In fact, it was the eighth wettest February on record and featured three days with more than an inch of rain, one of those greater than two inches. The warmth early in the month, with multiple 70+ degree days was broken up by a couple of cold spells, but overall warmth. Heading into meteorological spring, the weather turned much cooler and drier relative to average. March averaged less than two degrees warmer than the preceding month with two-thirds of the days below average. Four inches of rain fell, but that is more than an inch below normal.

Heading into April, temperatures rebounded to near average while precipitation returned to above average status with almost eight inches falling for the month over eleven rain days. Heading into May, temperatures rose above average, including one record - a 73 degree low temperature on the 21st. In fact, for the second half of the month, not a single day had below normal temperatures. Precipitation was about where it is expected climatologically.

Summer was wet with the three months of June, July and August recording a total of over 21.5 inches of rain, or almost 10.5 inches above normal. June finished 5th wettest on record and July 11th wettest, while August was also above normal. Because of all the precipitation, summer was also, on average, cooler than normal. In fact, a record morning low of 62 degrees was set on July 25 - a rarity when summer mornings usually start at or above 70. August temperatures started to warm more as expected, but couldn't make up for the relative cool conditions in June and July.

Typically temperatures relax heading into September, particularly the latter half of the month, but 2019 was an anomaly as the month was the warmest on record. September typically is about seven degrees cooler than August. Not in 2019, as it actually ended 1.3 degrees warmer than the usual hottest month of the year! All but one day in September recorded a high at or above 89 degrees and there were 13 days with highs of 95 or higher, including the hottest day of the year - 100 on the 16th! Not a single day recorded below average temperatures. Part of the reason for the heat was a temporary drought that lasted throughout the month, with only 0.12" of rain for September, third driest on record.

The heat continued into the first week of October as the month started with three consecutive daily high temperature records (96, 97, and 98 degrees) before a very wet system moved through on the 6th and 7th, dropping nearly 4.5" of rain. Nearly the entire rest of the month featured below average temperatures and many more rain events. October set a record for wettest in history with almost 13" of rain, including another six and one-half inches in the last week of the month. Two daily rainfall records were broken during the month, putting the city more than 20 inches of rain above normal with two months left to go in the year.

Once the script flipped cold in mid-October, it continued into November with no days above average through the first 18. In fact, the cold was reinforced mid-month with two days featuring record lows (20 degrees on the 12th and 17 on the 13th) and a record cold high temperature of 30 degrees also on the 12th. In fact, snow flurries also occurred on both the 11th and 12th. Temperatures warmed the second half of the month, including a high of 70 on Thanksgiving Day. A decent amount of precipitation in the final third of the month brought the total closer to average, though still finishing more than an inch below a typical November.

Finally, December didn't cool off at all, with a monthly average temperature that was just shy of November's average and a mix of above and below normal days. Precipitation again finished below average with just over 4 inches recorded. Snow flurries also fell twice during the month.

A month-by-month summary of average temperatures and precipitation can be found below.


Severe weather

In 2019, the Memphis office of the National Weather Service issued 294 combined Severe Thunderstorm and Tornado Warnings in their service area (161 Severe Thunderstorm and 43 Tornado). It is notable that the combined warning number is the fewest issued by NWS-Memphis in the past 20 years (at least). The previous lowest was 250 in 2013. With respect to Severe Thunderstorm Warnings, the 161 issued were also the lowest in the past 2 decades, lower than the previous record of 213 in 2013. The 43 Tornado Warnings ranked eighth fewest in the past 20 years. Also in 2019, there were 13 Tornado Watches and 9 Severe Thunderstorm Watches issued by the Storm Prediction Center that included some portion of the Memphis service area.

The Mid-South recorded 26 tornadoes, most weak, during 2019. There were four EF-2 tornadoes, all in northeast MS, with the rest rated EF-0 or EF-1. Within the eight-county Memphis metropolitan area, there were four tornado touchdowns. Most notable was an EF-1 twister that hit southeast Memphis on October 21st. In addition, EF-0 tornadoes touched down in western Tipton County, northwest Marshall County, and southeast Tunica County. For the year, the NWS-Memphis office received 268 severe weather reports (convective) within their service area.




The following represents a statistical recap of the weather for 2019 in Memphis. Another recap of  weather across the Mid-South for 2019, produced by the National Weather Service in Memphis, will be published soon.

Memphis International Airport, Memphis, TN


Temperature
Average temperature: 63.5 degrees (0.4 degrees above average)
Average high temperature: 72.7 degrees (0.7 degrees below average)
Average low temperature: 54.3 degrees (0.4 degrees above average)
Warmest temperature: 100 degrees (September 16)
Coolest temperature: 17 degrees (November 13)

Heating degree days: 2899 (66 below average)
Cooling degree days: 2479 (221 above average)
Days at or above 90 degrees: 90 (25.7 days above average)
Days at or below 32 degrees: 46 (3.2 days above average)
Last freeze/first freeze: March 24-November 12 (233 day growing season)

Records set or tied: There was only one monthly average temperatures that placed in the top ten warmest or coldest on record. September was the warmest on record, averaging 83.5° and featuring three daily record high temperatures and an all-time record high temperature for the month. In all, seven daily warm weather records and four daily cold weather records were set in 2019. These included:
  • May 21 (73°, record high minimum)
  • July 25 (62°, tied record low)
  • September 17 (99°, record high)
  • September 18 (99°, record high)
  • September 27 (95°, tied high record)
  • October 1 (96°, record high)
  • October 2 (97°, record high)
  • October 3 (98°, record high and all-time October max. temperature)
  • November 12 (30°, record low maximum and 20°, record low)
  • November 13 (17°, record low)

Comments: After 2018 ended just a bit warmer than the 30-year climate average for temperature, 2019 ranked in the top 17% warmest (tied for 24th) in the 146-year historical record at Memphis. 90 days saw high temperatures at or above 90 degrees (tied for 11th most on record). 46 days experienced freezing or sub-freezing temperatures.

Temperatures for the year (lows/highs) are plotted in dark blue against the normals (brown), record highs (red) and record lows (light blue).  Where the dark blue extends above or below the brown indicates temperatures above or below normal, respectively.

Precipitation
Annual total: 73.65" (19.97" above average)
Days with measurable precipitation: 120 (12.3 days above average)
Days with 1"+ precipitation: 27 (9.6 days above average)
Wettest day: 3.39" (October 6)

Total Snowfall: 0.2" (3.6" below average)
Days with a trace or more snowfall: 8 (5.2 above average)
Days with 1" or more snowfall: 0 (1.2 below average)
Greatest snow depth (6am CST): 0

Records set or tied: The total precipitation for the year (73.65") ranks 2019 fourth wettest on record. The month of February (8.78") was the eighth wettest on record. The month of June (9.51") was the fifth wettest on record. The month of September (0.12") was the third driest on record. The month of October (12.95") was the wettest on record. Daily records included:
  • June 7 (2.80")
  • July 16 (2.28")
  • October 6 (3.39")
  • October 26 (3.01")

Comments: Overall, 2019 ended as the wettest year in the 148-year record in Memphis. 27 days recorded an inch or more of liquid precipitation; six days had more than 2" and two days recorded more than 3".


Precipitation accumulation for 2019 is plotted as the dark green line, compared with a normal year in brown. Precipitation climbed above normal early in the year (by mid-February) and remained well above average the remainder of the year. A wet summer and record wet October pushed the anomaly even higher as the year went on, ending 20" above average.

Miscellaneous

Peak wind gust: West / 67 mph (June 19)
Average wind: 7.6 mph
Average relative humidity: 70%
Average sky cover: 60%

Click here for monthly/daily statistical recaps for Memphis International Airport.

Cirrus Weather Solutions / MemphisWeather.net, Bartlett, TN


Temperature (data not available Sep 24-Oct 5)
Average temperature: 61.6 degrees
Average high temperature: 72.5 degrees
Average low temperature: 51.5 degrees
Warmest temperature: 100.1 degrees (September 16)
Coolest temperature: 14.6 degrees (November 13)

Heating degree days: 3329
Cooling degree days: 2131

Precipitation
Annual total: 61.31" (automated rain gauge), 68.05" (manual CoCoRaHS rain gauge)
Wettest date: 3.33" (April 13) (automated gauge)

Total Snowfall: 0.2"
Days with a trace or more snowfall: 5
Greatest snow depth: 0.2" (January 20)

Miscellaneous
Peak wind: South-southwest / 35 mph (March 9)
Average relative humidity: 78%
Average barometric pressure: 30.05" Hg

Click here for monthly/daily statistical recaps for Bartlett, TN.

MWN Forecast Accuracy


Number of MWN forecasts produced and verified in 2019: 542
MWN average temperature error: 2.23 degrees
MWN forecast temperatures within 2 degrees of actual: 71.1%
MWN average dewpoint error: 2.04 degrees
MWN forecast dewpoints within 2 degrees of actual: 66.1%

MWN's forecasts extend out five periods (2.5 days, or roughly 60 hours) and the numbers above represent the error/accuracy of the entire 2.5 day period. Historical accuracy statistics can be found here.

Erik Proseus
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!
MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder