August 23, 2018 Drought and Agriculture Report – Temporarily Better

Written by Sig Silber

There was not that much change this week overall, but a few states had significant improvement. Unfortunately, the short-term forecast is not favorable. But drought or not, the crop results this year are sensational. Go figure!

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New Forecast which covers the end of August and Fall.

 Information sources: Although not limited to the following, most of the material in this report comes from:

This report is now organized as follows:

1. Present Drought Conditions
2. Last Week’s Weather
3. Information from our Weekly Weather Column (the forecast maps auto-update) and combined with brief commentary from me provides a forecast which I attempt to interpret re the likely change in drought conditions
4. U.S. Crop Information
5. International Crop Information and related weather
6. Prior month’s weather and month-to-date weather excluding the prior week when I have that information. Drought is based on cumulative deficits.
7. A science theme if we have one.
8. Reference Information.

1. Present Drought Conditions

The U.S. Drought Monitor is a comprehensive way of understanding the drought situation for the U.S. It is issued every Thursday and reflects the conditions as of the prior Tuesday. Drought is defined as a moisture deficit bad enough to have social, environmental or economic effects. Thus, more factors than recent precipitation are considered and more information on how it is done is found at the end of this report.

Below is the same map but just CONUS and with statistics and below that map I have provided a cut-out of the statistics which I think you can click on to enlarge.

The graphic below shows the one-week change in drought intensity. Yellow is bad. Green is good.

This pair of maps might make it easier to get a general idea of what is happening in the worst part of the drought area.

Last Week	This Week

Now we show the same information by region. The yellow is where the drought has been upgraded.

Slight deterioration on balance

Mostly improvement on balance.

Improvement

Substantial improvement north, deterioration along Gulf Coast

Deterioration in small area to the west

Mixed but New Mexico fared well

Some may find this way of looking at things useful and I hope these graphics are not too small to read. I did not make them so you could click on them individually but you can click on the whole graphic and it may enlarge. But I think you get the picture. It has been a rapid onset and hopefully it’s demise will also be fairly rapid.

Some might find this animation of twelve weeks of change useful;

Here is the discussion which was issued with the Drought Monitor today.

This Week’s Drought Summary

Areas of low pressure brought heavy to excessive rainfall to many parts of the U.S. during this past drought week (August 14-21). Some storms brought more rainfall to already inundated areas such as the Northeast, but some activity occurred over drought regions badly in need of moisture, including the Central and Southern Plains, the Midwest, and the South. Other areas, especially along the northern tier of the country, continued to dry out amid a combined lack of rainfall and anomalously high temperatures. Some areas of northern Michigan and Wisconsin averaged daily maximum temperatures 6-8 degrees F above their typical average for this time of year.

Northeast

Rainfall was above normal across most of the region, allowing for some small improvements in western New York, where the moderate drought (D1) footprint was reduced. This week’s rainfall led to the return of normal conditions in the same general region, along with southern Vermont, southern New Hampshire, and central Maine. The remainder of the region is drought free, and in some instances extremely wet. Pennsylvania has received its record highest year-to-date (January-July) precipitation in its 124 year record, according to NOAA NCEI.

Southeast

Most of the Southeast has received adequate to above-normal rainfall this summer. At this time, no areas of the Southeast are experiencing any drought conditions, although there are a few pockets of short-term abnormal dryness (D0) in Alabama, most notably leading to some low stream flows. These conditions expanded a bit in the western part of the state this week, but improved to normal in the east compared with the previous week.

South

Drought has plagued this region, but heavy, and in some instances, extremely heavy rainfalls, (ranging from 1 to 6 inches or more) brought much needed relief as most areas saw vast improvements or, at the very least, no degradation. In extreme northeastern Arkansas, several counties experiencing D2 conditions received 6 or more inches of rain over the past week. In facet, enough rain fell over the state that widespread 1-category improvements were made. Many stations received record rainfall for the month of August, including Long Pool (12.35 inches), Clinton (12.41 inches), and Murfreesboro (12.11 inches), leading to much improved conditions across the state, with no primarily drought and only lingering long-term dry conditions. Similarly, Oklahoma saw drought conditions fade as heavy rains fell, bringing normal conditions back to a large swath of the state stretching from the northwest to the southeast. Conditions also improved in Louisiana, northern, and western Texas, while dryness spread in southeastern Texas.

Midwest

Some regions of the Midwest received excess rainfall this week from heavy downpours, while other areas mostly missed out on the events, leading to some improved drought areas and some degraded drought areas. Along the U.S./Canadian border of Minnesota, several areas reported precipitation accumulations among their lowest 20 percent (since April 1), leading to expanded abnormal dryness (D0) and moderate drought (D1). Likewise, Michigan’s northern lower peninsula has continued to experience below-average rainfall, leading to reported dying foliage (ferns). Here, an area of moderate drought (D1) expanded and severe drought (D2) was introduced. Rainfall was deficient in central to southern Iowa, where D0, D1, D2, and a bit of D3 (extreme drought) expanded. Parts of northern Illinois also remained dry over the past month or so, leading an expanded area of abnormal dryness (D0), while northern Indiana and northern Ohio saw some improvement. Missouri saw more than 5 inches of rain fall in places. Conditions in this state improved considerably in many areas, although rainfall, even more than an inch or two, wasn’t enough to overcome the lingering longer-term dryness in other areas.

High Plains

Similar to the Midwest, the northern tier of the High Plains saw conditions continue to dry out over this past week, exacerbated by high temperatures in some areas. Mercer County, North Dakota, for example, saw temperatures reach 104 degrees F on two days and 10 consecutive days of upper 90s. Crops have been impacted as soil moisture is depleted, with very dry topsoil and subsoil. There are reports of corn burning and severely stressed soybeans, among other impacts. As such, areas of abnormal dryness (D0), moderate drought (D1), and severe drought (D2) were expanded in various parts of the state. Eastern Montana saw an expansion of D0, including along the North Dakota border. Nebraska and Kansas, on the other hand, were the recipients of heavy rainfall events, which led to improvements across their drought regions. Although rainfall was 2-6 inches in several inches in places, long-term dryness persists across parts of the regions and thus was not adequate to erase all drought. However, two category improvements (D3 to D1) were made in southeastern Kansas, for example, as the rain did vastly improve conditions there. In Colorado, D1 was reduced in El Paso and Douglas Counties, which received 1 to 4 inches of rain over the past few weeks, improving conditions there.

West

Most of the West continues to experience dry conditions and drought, with dozens of wildfires burning record acreage; however, while conditions remain poor, no areas required further degradation this week. The only change made this week occurred in far eastern New Mexico, where rainfall was 1 inch or more above average for the week. This allowed for 1-category drought improvements of extreme drought (D3), severe drought (D2), and moderate drought (D1).

Alaska, Hawaii, and Puerto Rico

No changes were made to the depiction in Puerto Rico this week. The upper panhandle of Alaska recently received rainfalls in excess of 13 inches over an 8-day period (August 6-13) and thus the area of abnormal dryness (D0) from Yakutat through most of Glacier Bay National Park to around the coastal region of Silka improved to normal on the drought scale. Conditions were dry in Hawaii, where severe drought (D2) replaced the existing moderate drought (D1) area over southwest Maui and Molokai, and D1 expanded eastward over south Maui, where dry conditions were reported over leeward areas of Maui County. There are federal reports that pasture conditions are poor over the lower leeward slopes of Maui and Molokai. A small area of D0 was also introduced on the lower slopes of south

Looking Ahead

Over the next week, beginning Tuesday August 28, up to 2 inches of rain is forecast for western Colorado and western New Mexico, where extreme (D3) and exceptional (D4) drought conditions prevail. No rain to less than half an inch are forecast for most of the remainder of the West. Between 0.1 and 2 inches are forecast for most of the rest of the U.S. at this time. Looking further ahead at NOAA’s Climate Prediction Center (CPC) 6-10 day Outlook (August 26-30), the probability of dry conditions are highest in the Plains, with a bullseye over western Oklahoma, while wet conditions may occur along the northern tier of the U.S., the Pacific Northwest, and Alaska. During this period, below-average temperatures are expected in the West while above-average temperatures are forecast for the eastern two-thirds of the country, particularly stretching from the Midwest to the Northeast. Looking two weeks out (August 28 – September 3), above-average temperatures are expected across the eastern two-thirds of the U.S. and stretching across the southwestern U.S./Mexico border. Below-average temperatures are expected over most of the West. The probability of above-average precipitation is highest over the North and Northwest with the highest probability of dryness expected over western Oklahoma.

Wildfires are happening.

And we do not want to ignore floods.

Here is what happened with precipitation during the most recent week.  The maps are in sync with the crop reports.

It is useful to look at temperature in a few different ways.

First let’s look at the Minimum Temperature.

And now the weekly maximum temperature

And for many purposes the average deviation from Normal or Climatology is very useful.

And here is a graphic that pulls a lot of information together. Image provided by the NOAA/ESRL Physical Sciences Division, Boulder, Colorado see website. It shows the demands of the atmosphere for moisture from the ground and is based on temperature, wind, relative humidity and solar radiation. It tells you nothing about how much precipitation you will get but how much you need to retain the same level of soil moisture.

And here is one impact – vegetation

Soil Moisture is a very important part of understanding drought. 

Surface	Subsurface
The numbers in parentheses show the changes by state. The number of states with Topsoil (near-surface) deficiencies has decreased by 5 from last week and the number of states with Subsoil (deeper) deficiencies has decreased by 3.
The number of states with Topsoil (near surface) surpluses has increased by 2 from last week and the number of states with Subsoil (subsurface) surpluses has increased by 1. It is not always easy to know how to relate to a moisture surplus. Is it a positive moisture reserve or is it too wet to work the ground?

3. Current Forecast for Precipitation.

First we show the Seasonal Forecast through November which was issued on August 16 with the full Seasonal Outlook and then the Month of August Drought Forecast Issued on July 31. These two forecasts are issued by the same agency but to obtain them you need to access two different links here and here. We either show the latest or both in this report. Sometimes we show them in more than one place in this report for the convenience of the reader. 

And now the prior one month forecast for August.

And now the current precipitation forecasts so that we can make our own assessment of the drought forecast. Here I provide the weather forecasts for different periods of time in August which should allow the reader to assess the likelihood of this forecast working out as shown over the next three to four weeks. (Since we publish this week on Thursday, we have updated the discussion for the Week 3 – 4 forecast which was updated on Friday August 24). This is important as the current Day 6 – 14 forecasts and the week-old week 3 – 4 forecast overlap to some extent.

For reference purposes here is the precipitation information for the prior seven days.

Now let’s look at the forecasts. Because temperature is so important right now re this drought I have switched over to the same format we use on Mondays.

First Temperature

This shows magnitude rather than probability of  being higher or lower than Normal and shows the middle day of the five day period.	Fairly stagnant pattern but warm in some of the most seriously impacted drought areas.		↑ ←  The Week 3 – 4 forecast is not favorable for the Gulf Coast part of Texas and Louisiana nor the Northern Tier.

And then Precipitation

The five day QPF is shown above. The units are different than the other maps i.e. in units of precipitation (inches) not probabilities of exceeding or being less than climatology.	Fairly stagnant pattern. But it is not favorable for either the Southwest or Southern Plains drought areas. Part of the Southwest will get some Monsoon relief from the Week-2 forecast.		↑ ←  The current Week 3 – 4 forecast is favorable for the Southwest drought area but not for the Southern Plains drought area as the updated forecast calls for drier than normal.

Here is another useful graphic from my weekly report which also updates automatically.

And one more.

4. U.S. Crop  Information

Below are more details and there is more information this week as the planting season advances.

This summarizes the situation which is not very much different than the report last week. In some cases there is slight improvement and this is best seen in the detailed tables below. It is getting to be difficult preparing this table separate from the information above and below. The reason for that is that in general there are at this point in time three parameters reported:

1. percent planted

2. percent that has developed to a key point

3. crop condition

Plus there are two reference points: last year and the five year average. So it is harder to assess the six measurements and arrive at a single conclusion for a crop but I have taken my best shot at it. For those with a more serious interest I suggest you review the tables below and the text summary above which is what I have done to populated this table which has not changed since last week.

* These two situations are not as bad now as they were as more states enter the picture.

The information in the table below is summarized in the above discussion but in the table below, it is broken down by State. 

5. International Crop and Weather Related Information

Sometimes a map is useful. It was not published last week.

I am now routinely including the precipitation report for Mexico since storms do not respect borders.

Here is the four-month result of these dry weeks.

6. Prior Month and when available the Current Month-to date Weather (excluding prior week)

State Rankings. We showed these last week but I am showing them again as it is a very useful graphic.

Temperature	Precipitation

Here is the recent history shown in this report as the month of August month to date average anomalies.

First precipitation

And then temperature:

You can generate a wide variety of different graphics here.

7. Science Theme When we Have One.

No Science Theme this week.

8. Additional Reference Information

A more complete description of

Sequence of drought occurrence and impacts for commonly accepted drought types. All droughts originate from a deficiency of precipitation or meteorological drought but other types of drought and impacts cascade from this deficiency. (Source: NDMC)

Source:  National Drought Mitigation Center, University of Nebraska-Lincoln, U