Too Much, Too Little, Too Late: Drought Precipitation Conundrum! A Presentation to the RMSAWWA/RMWEA Joint Annual Conference Steamboat Springs, Colorado Tuesday, September 17, 2002 John F. Henz Senior Project Meteorologist HDR Hydro-Meteorological Services

Hydro-meteorology: Providing solutions to weather conundrums John Henz, Certified Consulting Meteorologist or C.C.M. HDR H ydro- M eteorological S ervices El Nino and La Nina confusing the drought What will Winter hold? Drought? Average Or Excess Precipitation? Fire, Mud, Floods: what to do Precipitation questions

Way too much plus mud after fire!!!!!

“Too much” again!

“Too Little” / “Too Late” for Agriculture!

Frederic Remington knew the value of water in the West “The Fight for the Waterhole” 1903

So did Stanley Kubrick in 2001: Space Odyssey the more things change the more they stay the same!

Colorado’s Water wars have Started! August 12, Rocky Mountain News headline Golden “at war” with downstream users; loses Continued “drought-like” conditions: will they persist or is a change developing? What will Winter hold? Drought? Average Or Excess Precipitation? How far could we look ahead if we wanted?

“conundrum”: a puzzle or mystery usually solved by a riddle.

Three men agree to share a cab from the airport into town. When they arrive, the meter reads $25. Each man gives the driver a $10 bill. She hands them five $1 bills as change. Each man takes one of the $1 bills. They give the driver the remaining two $1 bills as a tip. Each man has now spent nine dollars and the driver has two dollars for a total of $29. Where is the other dollar? Your challenge is to explain this paradox

Three water suppliers face a severe drought. They each ask a meteorologist how much snow will fall in the mountains. One meteorologist says 70% of normal; the drought is in control and shows no signs of departing. The next meteorologist says 100% of normal: the drought is waning, El Nino is coming, but it’ll take two winters to catch up. The final meteorologist says 120% of normal; El Nino will chase the drought away. Your challenge is to who to believe The Water Supplier Conundrum

What’s ahead for the WY02/03?

Where we are now! Very, very dry!

Here’s what NWS expects: is where we’ve been?

El Nino/La Nina Storm Tracks El Nino tends to be wet during winter La Nina tends to be dry during winter La Na Da: Neutral tends to flip/flop depending on cycle

Why has it been so dry and warm? La Na Da’s Split storm track around Colorado.

The El Nino/La Nina Cycle is a dynamic

Summed number of years per decade the basin average precip is +/- 2” of normal. Notice the in-sync(’90-’50) and out of sync(’60-’90} cycles

Is Colorado Decadal Precipitation Cyclic with El Nino and La Nina?

So how have El Nino and La Nina’s impacted Colorado winter precipitation? La Nina’s tend to produce below normal snow packs and meager summer rains. Favor development of multiple dry year sequences or droughts El Nino’s tend to support average to above average winter snow packs and above average spring general storm rain/snow and summer monsoon rains for 6-18 months La Na Da’s can go either way! (The key?)

All La Nina’s are not created equal!

La Na Da or neutral periods are very different!

Current 01/02 El Nino in dashed black : Can you spot a trend?

82/83, 91/92, 95/95 and 97/98 El Nino’s Can you see the differences?

00/02 El Nino’s development. Compares closest to 86/87 El Nino

Three El Nino’s: three different patterns!

00/02 El Nino’s development. Compares closest to 86/88 El Nino

Is the 86/87 El Nino an analog” for 01/? It would be nice but differences exist.

Denver El vs La: on average only El Nino on top “looks wetter” and is esp. Spring La Nina on bot. “looks drier” and is esp. Oct-Mar What about La Na Da’s?

Grand Jct. El vs. La On average only El Nino on top “looks wetter” and is esp. Fall and Spring La Nina on bot. “looks drier” and is esp. Mar-May What about La Na Da’s?

New Mexico: El Nino Avg Jan-Mar Precip El Nino = Much wetter than normal 129% of normal in the Northwest 200% of normal in the SE plains

Colorado: El Nino Avg. Jan-Mar Precip. El Nino = Moist, i.e., +/- 15% of normal Colorado West of CD: 88% of normal East of the CD South Platte, San Luis, and Arkansas: 109% to 117% of normal Far east Plains: 140%

Wyoming: El Nino Avg Jan-Mar Precip El Nino = Dry side of normal Plains: 74%(NE) to 93% (SE) of normal Mountains: 80% to 94% of normal “West Slope: 80-87%

El Nino Wet in NM or Dry in Mt

El Nino Wet in NM or Dry in Mt: Hmmmm

What’s ahead for the WY02/03? Work in progress

What will Winter hold? Drought? Average Or Excess Precipitation? A moderate El Nino is developing. West of the Continental Divide snow-pack should reach 80% in Colorado River basin and up to 120% normal in Southwest basins East of the Continental Divide not sure yet. NO strong signal yet! Averages support 110% of normal but range is 60% to 130% Work in progress

What will Winter hold? Strong El Nino? La Na Da? Or La Nina? Key to drought recovery of our reservoir storage will be two or more normal to wet winters in a row. One wet winter will not be enough especially if we go into another “dry period” in parts of the state. East of the Divide soil moisture values are very low and we need the return of winter and spring general snow and rain storms. It has been 9 years since we had both significant winter and spring plains snow. Will they both return? La Na Da research is the key! Work in progress

How far could we look ahead if we wanted? Extended trend analyses of tree ring data Eigenvector analyses of precipitation extreme where basin average precipitation is > 2” above or below normal Physical cause/effect data base partitioning of storm tracks, jet streams and La Na Da’s Next a “50-year” experimental trend outlook for Colorado precipitation. Note this outlook is a work in progress! Not ready for prime time only discussion

Summed number of years per decade the state river basin average precip is +/- 2” of normal. Work in progress

If this trend analysis is correct, more dry than wet decades lie ahead : early drought tempered by wet mid- decade 2010’s: Significant drought possible 2020’s give a “moist breather” early Mid-2020’s to early 2050’s a 30-year period of very dry conditions across Colorado and the western US. Work in progress

Three men agree to share a cab from the airport into town. When they arrive, the meter reads $25. Each man gives the driver a $10 bill. She hands them five $1 bills as change. Each man takes one of the $1 bills. They give the driver the remaining two $1 bills as a tip. Each man has now spent nine dollars and the driver has two dollars for a total of $29. Where is the other dollar? No money has been lost only the meaning and interpretation of the words!

The storm.. Is El Nino coming?

Yes. The end!