The Drought Discussion Podcast

Episode 3. Seasonal Climate Outlooks and Grass-Cast - July 29, 2022

August 05, 2022 Drought Learning Network Season 1 Episode 3
The Drought Discussion Podcast
Episode 3. Seasonal Climate Outlooks and Grass-Cast - July 29, 2022
Show Notes Transcript

We bring you this podcast with the intention of helping you figure out how much rain to expect this season and - if you’re managing rangelands - how much forage you might get. During the growing season we share seasonal precipitation outlooks from NOAA’s National Weather Service Climate Prediction Center and grassland productivity forecasts from Grass-Cast. Grass-Cast gives you a heads-up in late-spring and early summer for how well your rangeland grasses could grow during the upcoming summer season, depending on whether precipitation in your area ends up being above, near, or below-normal.

Please visit
https://bit.ly/droughtpod to view the maps discussed in this episode. Or click here to load a PDF.

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[00:00:00] Caiti Steele: Thank you for joining us to listen to the Drought Discussion Podcast. We will be sharing the latest drought, precipitation and forage outlooks for Arizona, New Mexico and the Southern Plains. The information in this podcast is best used in combination with local knowledge of soils and topography, plant communities, grazing history and other conditions.

[00:00:21] It should never be used as the sole basis for decisions or to replace local observations of the land you manage. 

[00:00:30] I'm Caiti Steele, Southwest Climate Hub Coordinator, and Director of the ARID project at New Mexico State University.

[00:00:36] Tonya Bernadt: And I'm Tonya Bernadt, the Education and Outreach Specialist for the National Drought Mitigation Center or the NDMC. Thanks for joining us today. 

[00:00:45] Caiti Steele: Welcome to the third edition of the Drought Discussion Podcast. So once again, we're delighted to welcome Julie Elliott who joins us to talk about the latest Grass-Cast maps for the Southwest and the Southern High Plains. And Julie is a rangeland management specialist with the Natural Resources Conservation Service and liaison to the Northern Plains Climate Hub.

[00:01:05] Tonya Bernadt: And we also have Curtis Riganti with us. Curtis is a Climatologist and United States Drought Monitor author with the National Drought Mitigation Center. In these podcasts, he helps us to understand the seasonal precipitation and temperature outlooks from the National Weather Services Climate Prediction Center.

[00:01:23] We take a look at these outlooks because knowing how much precipitation to expect helps us to interpret the Grass-Cast predictions. Just a reminder for images of the maps that Curtis and Julie are discussing, please go to bit.ly/droughtpod, all one word, or you can Google drought discussion podcast. Over to you, Curtis.

[00:01:49] Curtis Riganti: Thanks again for having me on Tonya and Caiti.. So quick update, we're recording this on the morning of July the 29th. So we still have some long-term drought conditions going on in most of New Mexico right now, a smattering of anything from moderate to exceptional drought, with most of the worst conditions still being located in the High Plains portion of New Mexico.

[00:02:14] So the Eastern part of the state, and we do still have some drought conditions occurring across most of Arizona as well. Over the last week or so we have seen some more improvements to the drought situation, particularly in the Sangre de Cristo mountains of Northern New Mexico and then scattered areas across Arizona.

[00:02:33] So looking forward, we're gonna take a look at a couple of the climate prediction centers maps here. Looking out to three months, this is a forecast for the August through October period now again issued July 21st. The forecast leans towards below normal precipitation for roughly the Eastern half to two thirds of New Mexico, all of the Texas panhandle and in Southwest Kansas and most of Eastern Colorado.

[00:03:00] The highest chances for below normal precipitation during this period extend from roughly Amarillo, Texas, and Western Kansas, Southwest Nebraska, Central Colorado, and into Wyoming and Southern Idaho. Meanwhile, we see equal chances for below or above normal precipitation during this period covering the Western, roughly third, of New Mexico and all of Arizona.

[00:03:27] So looking ahead now for the drought outlook, for the seasonal drought outlook, we see that drought removal is actually likely in parts of far Western New Mexico into central and Southeast Arizona. While some improvement to the drought situation is likely to occur in the Southwest portion of New Mexico.

[00:03:49] Most of Arizona, and even south central parts of Utah. Drought is expected to remain in South Central Utah and Northern Arizona, but it is expected to improve. Again, this forecast is as of July 21st valid through Halloween and issued by the Climate Prediction Center. So that's all I've got for the forecast, back to you guys.

[00:04:12] Caiti Steele: So Curtis, we are seeing that only Arizona has a fairly optimistic outlook for precipitation and those equal chances really over our entire Southwest and Southern Plains region. But if we look at the temperature, that seems quite a solid prediction. What does that mean? If we are looking at storage growth, what does the higher temperatures mean with normal precipitation?

[00:04:41] Curtis Riganti: Yeah, that's a good question. So with near normal precipitation, if your temperatures are above normal, generally speaking, all else held equal, that's going to lead towards more rapid loss of near surface moisture. Exactly how that impacts forage growth. I'm not a phenologist, so I'm not an expert on that, but I can say with some confidence that if the temperatures are consistently above normal, you're likely to lose at least high level soil moisture more quickly than you otherwise would. 

[00:05:16] Caiti Steele: So thanks Curtis, for that explanation. That makes sense to me. I'm guessing if we lose that soil moisture, that's not going to be terribly good for forage growth. 

[00:05:24] Curtis Riganti: Yeah, I would imagine not. 

[00:05:26] Caiti Steele: No. We'll pass over to Julie now, who is our NRCS specialist and she has the information about Grass-Cast outlooks that've just been published today. So Julie, take it away. 

[00:05:41] Julie Elliott: Thanks Caiti. I thought I would share some precipitation information as part of my Grass-Cast map discussion. It just helps to make sense of what the maps are saying. And it, now this will be a look back information on precipitation, not a look forward as Curtis was talking about.

[00:05:58] So I'm gonna focus on the worst case scenario maps for Grass-Cast or the below average precipitation scenarios. We're still gonna peak at the other. But I really want to encourage people to plan for the worst and hope for the best today. I'm gonna start on the west end of the Grass-Cast forecast area and go east.

[00:06:17] So we'll start in Arizona. Just before I dive in that, I want to remind listeners that Arizona and New Mexico have two distinct growing seasons. They have a spring season that ended in May, and then a summer season that runs from June 1st through August. The summer growing season runs on summer precipitation.

[00:06:36] There wasn't any moisture this year to carry over from the spring, anyway. The precipitation discussion's gonna be focusing on what's fallen since June 1st. So I'm talking about average or normal precipitation here. I'm referring to the average of the precipitation for the past 30 or so years. I'll compare how our current year looks to that 30 year average for the summer growing season.

[00:06:58] So again from June through July 25th, because that was information that was plugged in to create the Grass-Cast maps, then the average or that normal forage production that I'll be comparing Grass-Cast to is that historical data based on the weather and vegetation growth for the past 30 or so years.

[00:07:17] So now let's dive into Arizona. There's quite a patchwork of precipitation in Arizona from less than 50% of the normal to more than a hundred percent of normal. The extremes are in the Northwest quarter of Arizona and Pima county in the south, which have seen 25 to 50% less than the average precipitation so far this summer. While the Southwest counties and parts of Maricopa have seen a hundred percent or more precipitation in average so far this summer. At least again, as of July 25. So how these precipitation extremes influence the Grass-Cast production forecast maps. Now recall Grass-Cast gives us three forage forecasts, one based on below normal precipitation, one based on a normal precipitation scenario, and then one for above normal precipitation scenario.

[00:08:08] So in the Grass-Cast production forecast for Arizona under the below normal precipitation scenario has changed in these last couple weeks to show more areas predicted to actually get near average production or even above average production and less of the areas predicted to get below average production.

[00:08:29] So, overall, that sounds pretty good. But that worst case scenario for Arizona as a whole really isn't too bad except, that center of Pima county and Northwest Yavapai that have missed the rains, and if that continues, they could see total grass production losses of 30% or more. There's 15 to 30% reductions show for the majority of the rest of Yavapai county, as well as Southwest Coconino and most of Mohave county. 

[00:08:58] Caiti Steele: This all sounds quite promising for Arizona forage production, Julie, but what if rain stops tomorrow? I do have my fingers crossed by the way, so I don't invite fate. 

[00:09:08] Julie Elliott: Even if the rainfall spigot shuts off tomorrow, Grass-Cast predicts that Mojave and La Paz county along the California border to see anywhere from five to 30% increase in above ground production to the end of the growing season and this great outlook extends east across most of those two counties even catching the Northwest corner of Yuma county, the very Northeast corner and west corner of Pima, the south two thirds of Maricopa and the west two thirds of Penal county.

[00:09:38] Caiti Steele: If we take a look at Arizona as a whole, where do you think it's gonna be hardest to figure out the end of season forage production? Like who's gonna have to do the most work in figuring that out. 

[00:09:48] Julie Elliott: Right? Well, there's a couple Mojave and Pima county are those counties right around surrounding those areas.

[00:09:54] If you're looking at those three maps, you might notice that there's a bit of a head scratcher because you've got the extremes. There is the full range of possibility from the very worst to the very best, and everything in between. So if you take a closer look at those Grass-Cast maps, assuming that we have a normal or average precipitation, Arizona really does turn around with only the Northwest part of Yavapai expecting 15 to 30% loss and five to 15% production losses in counties in that Northwest quarter, Central Pima county, and North central Maricopa. Pretty much the rest of the state is forecasted to at least hit an average, if not above average production with near normal precipitation. And listeners can already anticipate the trend. If we're near normal precipitation is good, above is better, and it is. Most of Arizona turns blue, which in Grass-Cast is a good sign, indicating five to 15% above average production.

[00:10:49] There's still some isolated six mile by six mile grid cells with less than average production forecast. So I encourage people to go check out the zoomable maps at grasscast.Unl.edu to see if that grid cell sits above you, especially if you're sitting in Mojave or Pima counties where that whole range of possibilities is squarely above you. 

[00:11:13] Tonya Bernadt: Julie, before you cover New Mexico, can you remind us of the differences between the Great Plains forecast and the Southwest forecast and what that means for ranchers in Eastern New Mexico? 

[00:11:23] Julie Elliott: Yes. Eastern New Mexico falls into both the Southwest forecast map and the Great Plains map, and it's really important for users to decide which map they need to look at.

[00:11:32] So again, the Southwest forecast maps reflects that two season growth pattern that I described at the beginning of my discussion here, where we have a spring and a summer growing season. Obviously the current Southwest maps are looking at summer production based on precipitation received since June 1st, the Great Plains maps use one continuous growing season from March and April through fall. So Eastern New Mexico listeners, you need to decide if you have two distinct growing seasons, spring and summer and if so, you need to pay attention to the Southwest forecast. But if you feel you have one continuous growing season, starting in the spring and running clear to the fall, then the great planes forecast applies to you.

[00:12:14] So let's just peek at the precipitation numbers. Precipitation from June 1st to July 25. Remember we're looking at the Southwest forecast. It was more than 50% below average in far Eastern Quay, Curry, and Roosevelt counties. Similar shortfall extended to a bunch of counties in that Eastern quarter of New Mexico ranging from Union in the north clear down to Lea in the south.

[00:12:39] There are also a couple spots in Luna and Dona Ana counties with five to 50% less precipitation than average. All these below normal precipitation areas have expanded since July 11th. 

[00:12:53] Caiti Steele: So Julie, I'm pretty sure that there's one of those spots in the valley, north of Las Cruces, where I live the creosote on the college ranch next to I-25 is still looking brown and my little acreage certainly not showing its usual swath of weeds either.

[00:13:08] Julie Elliott: Yeah, the monsoon rains can be so variable depending on where you are. We often hear folks talking about the rain stopped at the fence line, or stopped on the highway or the county road, whatever it is. If you're depending on rangeland forage, I just can't emphasize enough how important it is to be measuring the rainfall at your location and to be monitoring your grass production.

[00:13:29] These Grass-Cast maps are helpful to see trends and to look into the future that we can't do, but all these have to be taken in with it, your local information in mind. So clipping and weighing grass samples is the best way to know how much grass is growing, but even just using a ruler, a yard stick can help tune your eyes to see what's really happening or not happening with grass growth and not being duped into thinking things are really rocking and rolling because the grass is green. And it's not even green, although Caiti, that doesn't sound like that's a problem in your corner of the world yet. So I'll keep my fingers crossed for you that, that you can have the struggle of being deciding if green grass is growing or not.

[00:14:14] Caiti Steele: Thanks, Julie. 

[00:14:15] Julie Elliott: Yeah, let's take a closer look at the Southwest model predictions for New Mexico, assuming below normal precipitation. So Grass-Cast is a little more optimistic for grant county and the center of union county for above average production. Even with below average precipitation, Grass-Cast is slightly less optimistic for some of the counties in Central New Mexico, including parts of the three counties, Catron, Socorro and Cebolla, though those areas are still sitting with near 15 to 30% more production than average.

[00:14:49] There is less optimism than two weeks ago for the rest of the state with expansion of severe losses more than 30% in most of the counties on the east border, and in the Southwest corner. Losses of five to 30% reach across the Southern counties surrounding those areas that are hardest hit. In contrast, the Southeast corner of Lea county still looks good with five to 15% more production than the long-term average, under a less than average precipitation forecast for the future. 

[00:15:22] Not surprisingly using a near average precipitation scenario, the Grass-Cast forecast maps shrink the below average production areas and expand the areas with above average production though that east border counties from Quay south to mid-Lea and Eddy still suffer 15 to 30% production losses.

[00:15:41] If moisture conditions were to suddenly become above average, the worst locations in Curry and Roosevelt counties reduce their losses to mostly five to 15% below the long term average, while the majority of the rest of the state is forecasted to enjoy above average total production. So take home message here for Eastern New Mexico, right there those border counties is that even with great precipitation, Grass-Cast just does not see you crawling out of this debt. 

[00:16:09] Tonya Bernadt: So what you're saying is that even if we get above average precipitation in some of those Eastern counties in New Mexico, that moisture is maybe not likely to help forage growth this year. Does the great Plains map look anymore promising? 

[00:16:24] Julie Elliott: You're exactly right with your first statement, Tonya. Right, more moisture's not likely to help forage growth this year for some of those Eastern counties. And I'm afraid that the Great Plains map does not look any more promising. Those Eastern New Mexico residents are not gonna be surprised to hear that they're way behind on precipitation for the whole water year, October 1st to July 25th, except that small area in the center of Union county. Even Southern Lea county is behind on precipitation for the water year. The rest of New Mexico is at least five to 25% behind, but most of the Eastern state is 25% or more behind precipitation for the water year.

[00:17:05] So listeners are gonna be able to guess by now that looking at continued below normal precipitation scenario in the Grass-Cast maps that spring through fall growing season in Eastern New Mexico yields forecasts of deep losses, more than 30% of most of the area. And those who aren't in the worst category are in the next lowest of 15 to 30% losses in production.

[00:17:29] The only exception is the center of union county, which may slip by with near normal production. Even moving to near normal precipitation scenarios for the rest of the growing season still leaves grass-Cast showing most of the area 15 to 30% less production than average, with some expansion in the Union county and a few six mile by six mile grids in Colfax and Lea county looking at near average production. Overall, the July 26th maps are a tad bit more pessimistic than the July 12th grass-Cast maps for New Mexico for the Great Plains forecast. 

[00:18:06] Caiti Steele: So how about the rest of the Southern Plains area? We're seeing some really devastating pictures of Western Oklahoma that the Oklahoma Conservation Commission have been sharing on their Facebook page.

[00:18:17] Julie Elliott: Yeah, the outlook just is not very bright for the Plains this year, Caiti. Most of West Texas and Oklahoma are just very dry. For the Texas portion, if we compare the July 26 Grass-Cast maps, July 12th for continued below normal precipitation, we can see the expansion of moderate losses, 15 to 30% on the East border, the panhandle. There is also some expansion of the near normal production though, in Throckmorton, Young and Jack county. So there's a small area of hope, but for the most part, it's just looking tough. It is surprising how optimistic the Grass-Cast forecast is for the, a couple spots. The north central Hemphill county ranging from five to 30% more production, even with below normal precipitation through the rest of the growing season.

[00:19:07] The counties that have seen less precipitation shortfall managed to look like they may hold onto near normal production in the face of continued precipitation for shortfalls. The rest of the forecast area in Texas though, as I mentioned is at least 15 to 30% lost with most areas, just falling into the greater than 30% loss projection.

[00:19:28] Even moving to a near normal precipitation scenario, Grass-Cast just expands the areas of above normal forage production only a little and reduces the areas that could see that greater than 30% loss of forage. However, even if precipitation just really turns around on its head to the end of the year and becomes above normal.

[00:19:48] Only a few isolated areas managed to reach that near normal production, though, the good areas do expand a bit and even manage to keep into positive territory. Moving to our easternmost state, Oklahoma listeners will not be surprised, especially based on what Caiti was just saying. And, and the residents already know that they are not exempt from these dry conditions.

[00:20:10] Pretty much all the counties covered by the Grass-Cast maps have seen 25 to 50% below average precipitation. The only exceptions of the Eastern most counties only expect to see losses of five to 25% below average. Comparing July 12th to July 26 Grass-Cast maps we see an expansion of forecasted losses in the west, not surprisingly. The production forecast under a continued below normal precipitation from July 26 has deep losses of more than 30%. And we can see a patchwork of six mile by six mile grid cells in several Western counties with those same losses. Most of the counties in the panhandle are also projected to have more than 30% production lost. 

[00:20:53] More optimistic forecasts of near normal productions sit in Canadian, Grady, Cado, and north Comanche county area. The rest of the state has between five and 30% less production than average. If we switch to a near normal precipitation scenario, it really doesn't change the maps much. Just reducing the extent of those more than 30% losses. Even using an above average precipitation scenario, we do see some more counties into the near or even slightly above production categories.

[00:21:25] But at this point in the year, I would not put my money on that scenario playing out. Diverting north to the Southwest corner of Kansas and the Southeast corner of Colorado. The precipitation story really isn't any different, and you all already know that. The Grass-Cast maps for below average precipitation reflect this except for the Northwest corner of Baca and the Northeast corner of Los Animas county in Colorado, which are actually forecasted to have near normal or even 15% more production than the long term average.

[00:21:57] This is all very hard to follow, I know. So go to the Grass-Cast maps and check out the zoomable maps to see where your location falls and to get more specific information about the precipitation amount grass-Cast assumes you've received to date, the long term average to date, and how much more precipitation is being plugged into the model to create the maps.

[00:22:19] Keep in mind always that Grass-Cast cannot know what kind of grasses are actually on any particular acre nor how healthy the plants are, and it cannot reflect the impacts of past droughts or management on production. 

[00:22:33] Tonya Bernadt: So generally speaking with the exception of a handful of counties, Grass-Cast is giving us a pretty bleak outlook for forage production over the Southern Plains.

[00:22:43] Caiti Steele: Yes, Tonya, it does seem pretty bleak. The precipitation and temperature outlooks that Curtis described don't really give us much reason to be optimistic for conditions to improve in those areas, either. It does seem that this is the time to be cautiously pessimistic. 

[00:22:58] Julie Elliott: Just so listeners know, back in April the USDA did designate 33 New Mexico counties as primary natural disaster areas.

[00:23:07] This means the Farm Service Agency can extend emergency credit to producers in those counties, as well as contiguous counties in Arizona, Colorado, Oklahoma, and Texas. So definitely reach out to Farm Service Agency for advice and more information about this. And if there's other USDA programs out there that may help.

[00:23:25] Caiti Steele: Thanks, Julie, for your really thorough discussion of the Grass-Cast maps, it's been really helpful to have those interpreted for us. And thanks too, for telling us about the USDA programs that folks might be eligible for. I can't emphasize that enough, Julie makes a really good point. Please reach out to Farm Service Agency for advice about this drought and how you might be able to gain some kind of support in any of the difficulties you might be experiencing as a result of forage loss.

[00:23:55] Tonya Bernadt: Thank you again to Curtis and Julie for helping us interpret seasonal outlooks from the Weather Service and Grass-Cast. We'll be back in a couple of weeks to see how the seasonal outlooks may have changed and to check out what Grass-Cast maps are showing us. 

[00:24:08] Caiti Steele: Thanks to our listeners, too. If you have any questions, comments, or requests, please feel free to reach out to us via the podcast page, we'd be very happy to hear from you. And as always, fingers crossed we'll get some rain between now and next time. 

[00:24:22] Tonya Bernadt: This podcast is brought to you by the Southwest Drought Learning Network, National Drought Mitigation Center, Agro Ecosystem Resilience in times of Drought, the Sustainable Southwest Beef Project, the Southwest Climate Hub and the Northern Plains Climate Hub. Thanks for listening.