Still in drought? But is has rained!

As I look out my office window this morning, I can finally start to see the impacts of the recent precipitation in the green grass coming up through last year's dead crop on the hills south of campus. Green up is here and the precipitation over the past week has really given things a boost. 

I've been fielding quite a few questions over the past few days with respect to the moisture and the upcoming summer fire season. Will the moisture help diminish the fire activity this summer? What has the precipitation done to the drought? Will it be a dry summer? A hot summer? So here we go, a little blog to help answer some of these questions. 

Yes, western SD has gotten a decent amount of precipitation over the past 2 weeks (below top). Note also how central and eastern SD have missed out on a lot of that precipitation. And if we look at it from the standpoint of percent of average, you can see that western SD has been anomalously wet while eastern SD is anomalously dry. (below bottom). 

But let's stretch it back 60 days. Similar graphs as above but now for the last two months. 

A different picture starts to emerge. April was exceptionally dry statewide (and April is generally a wet month for the state). Much of western SD has gotten below average precipitation during the period, one reason you may still see lingering drought issues. 

Let's stretch it back to 120 days. Again, similar graphs as above. 

The dryness across the state really starts to emerge. The Black Hills has been one area of the state that actually has seen some decent moisture but the good precipitation there has been limited to the central and southern Black Hills--this is a result of more southerly storm tracks for the major precipitation systems this winter. Look at southeastern WY and CO east of the Rockies: it's been super wet down there. 

So where do we sit today with respect to drought? The most recent US Drought Monitor is below.

We remain in drought across much of the state. The good winter precipitation over much of the Black Hills has lifted those areas out of Abnormally Dry conditions and parts of SD in the Watertown area have been fairing well also. But look at the rest of the state: it remains pretty darn dry. And this is critically important as we are dead in the middle of the wettest time of year for the state! The precipitation we get now "carries" us through the rest of the year. So how do things look in the near future?

First, let's take a look at the short term. Below is the 7-day precipitation forecast from the Weather Prediction Center (WPC).

Alright, SD does have some green in it. That's good, right? Well... not really. We should be getting on the order of 0.75 - 1.0" of precipitation per week this time of year, depending on location in the state. Eastern SD may see that but western SD looks like we'll have a relatively dry week. So what's the two-week forecast look like? The Climate Prediction Center (CPC) has a forecast for that: top is temperature probabilities and bottom is precipitation probabilities. 

Note how conditions across the state are favoring warmer than average conditions while western SD also is likely to see drier than average conditions. Warm temperatures will increase evaporative demand which will pull the moisture out of the soil and transpiration will increase pulling water out of the plants. And if western SD is drier than average, we will start to see conditions deteriorate further during the month of June (again, another generally wet month for the state). 

Is there any relief in sight? Not really, if you trust the CPC. The 3-month outlook is below (June/July/August). Temperature outlook on top, precipitation on bottom. 

But can we trust the CPC? Well they base some of their forecasts from information obtained from the North American Multi-model Ensemble (NMME) projections. I'll leave it to you to look at it but, by and large, these projections are largely showing dry/hot conditions for SD. There is much more confidence in the temperature forecast than the precipitation forecast but still, not a rosy outlook. 

Think back to our last "bad" fire season across SD: 2012. What did it look like precipitation-wise then? Here is the monthly precipitation for the year from both 2012 and for 2021 (from Rapid City). 

Rapid City is actually drier than 2012 at this point in the year. The reason 2012 was so bad fire-wise was that July - August was ridiculously dry and hot (spring moisture was half-way decent that year).

To summarize, I still have major concerns regarding the summer fire potential (and the impacts to statewide agriculture). We've been dry, many areas of the state are current dry, and we are expected a hot/dry summer. I hope I'm wrong but the current data suggests we are in for a rough summer. 

Recent conditions across SD

In terms of temperature and precipitation, it's been an odd start to the spring. We've seen some ample precipitation across some areas of the state while other areas remain remarkably dry. The figure below is accumulated precipitation since April 1. 

Northeastern SD and the Black Hills really have been the primary benefactors of the recent precipitation. But when looking at departures from average during the same timeframe, the picture isn't quite as rosy. 

Let's stretch it back to the start of the year over western SD. The next three figures represent year-to-date precipitation in Buffalo, Rapid City, and Custer. Custer had been doing pretty good precipitation wise up through the middle of April, but they are starting to see the effects of the recent dryness over the past few weeks. 

Buffalo is pretty much bone dry. They did get some beneficial rainfall last week but definitely not enough to break the D3 Extreme Drought situation that they currently are in. It was probably enough to green things up a bit but that is about all. 

My concern is starting to become laser-focused on the temperatures forecasts for the next 1 to 2 months. We are running deficits in precipitation but if we get some serious heat in June to early July, that will push us over the edge and dramatically increase wildfire potential across the region. We don't have the moisture in the soils right now and if we increase the evaporative demand with warmer temperatures, it will tap out the moisture completely--bad news for wildfires and agriculture across the state. If we do get some heat, we'll likely see much expansion in the USDM. The forecasts for temperature in June and July (top and bottom, respectively) from the National Multi-Model Ensembles are below. 

That is a forecast that does not bring much hope to the region. Oh and by the way, the same models are showing drier than average conditions for the same time period. 

My current thinking hasn't changed much from my outlooks: I fully expect us to have a busy fire season in SD.