Written by Sig Silber
Updated at 4:50 pm EDT July 20 to reflect the updated Week 3 – 4 Forecast
The report this week shows a generally stable situation with some improvement in the hardest hit areas but with somewhat expanded areas impacted by drought. The newly released precipitation and temperature forecasts which we will report on fully on Saturday but we preview in this report strongly suggests the drought will get worse in the areas of most concern. But in the short term, there may be some improvement. In anticipation of that improvement being short term and being followed by the newly issued forecasts for August and the three-month period August through October, we have included a history of drought in Texas in the science section of this report.
New Seasonal Outlook through October | Prior Outlook for the month of July Only |
Precipitation Forecasts (temperature is also important but we will show that Saturday). Generally it is warmer than climatology for most of CONUS not a big surprise.
NOAA Early forecast for August 2018 | NOAA forecast for next three months |
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Information sources: Although not limited to the following, most of the material in this report comes from:
- The U.S. Drought Monitor (full report can be accessed here)
- Selected parts of our Weekly Weather and Climate Report (Monday’s full report can be accessed here) which has forecasts for the next 25 days and which auto-updates
- Selections from the Tuesday USDA Weather and Crop Bulletin (full report can be accessed here). Other useful sources of information that I regularly utilize are the National Integrated Drought Information System (NIDIS) which can be accessed here and the USDA NRCS Weekly and Weather Climate Update which can be accessed here.
Remember if you leave this page to go to links or if you have clicked to enlarge a graphic, in order to get back you need to hit the return arrow usually located on the left of your URL box on the upper left of the screen. Also most of the small graphics are designed to become full size when you click on them. If that does not work, an alternative way to view the larger graphics is to right click and then hit “view image”. That should always work.
Drought is complicated so there is much information that relates to drought which as made this Thursday Report start to become both length and not as well organized as I would like. So tonight I am attempting to do a better job of organizing the Report. This report is now organized as follows:
- Present Drought Conditions
- Last Week’s Weather
- 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
- U.S. Crop Information
- International Crop Information and related weather
- Prior month’s weather and month-to-date weather excluding the prior week when I have that information. Drought is based on cumulative deficits.
- A science theme if we have one: This week we provide a detailed history of drought in Texas. Texas makes a good case study because it is drought prone and not managed by the Federal Government as is the case for the water resources of most Western States. They are on their own and they have a population that is growing rapidly. See Section 7.
- 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.
Not much change |
Deterioration |
Some deterioration but weather forecast is favorable. |
You can see where Texas improved. See Section 7 of this report where we provide information on the history of drought in Texas. Three month forecast very unfavorable for this area. |
Slight deterioration but weather forecast favorable. |
Small improvement in Arizona and New Mexico which should improve more soon. Northwest deteriorated a bit. |
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.
Over the last week, relatively warm weather was common over much of the country, particularly in Kansas, Missouri, Arkansas, Wisconsin, Washington, Oregon, and California. Widespread rainfall fell over parts of Pennsylvania and New York, Illinois, and from southwest Nebraska to the Michigan Upper Peninsula. Elsewhere across the central and eastern United States, rainfall, some moderate to heavy, was generally hit or miss. In the western United States, monsoonal rains fell over Arizona and New Mexico and parts of southern Utah and Nevada, keeping temperatures in the areas receiving rain near or cooler than normal. Most other areas, with the exceptions of eastern Wyoming, the Montana high plains, and parts of Colorado, stayed mostly dry.
Northeast
Relatively warm temperatures continued in parts of the Northeast this past week, while heavier precipitation fell over parts of West Virginia, Pennsylvania, and New York. As short-term dryness persisted in parts of New England, moderate drought and abnormal dryness continued to expand. Precipitation that fell in northern New York this week prevented further degradation of conditions near the Canadian border. Moderate drought was also introduced north of the Interstate 90 corridor in western New York near Buffalo and Rochester. From central Maryland eastward to southern New Jersey, a very wet May and early June abruptly gave way to a dry and warm weather pattern that led to the abnormal dryness. Parts of this area received heavy rain on Tuesday morning, which will be taken into account for next week’s map.
Southeast
Aside from cooler conditions along the spine of the Appalachians and mild conditions in most of North Carolina, warmer than normal weather occurred in much of the Southeast over the past week. Heavier rainfall over Alabama allowed abnormally dry conditions near Mobile and in northeast Alabama to improve. Meanwhile, little to no rain fell over parts of North Carolina east of the Appalachians. The ongoing short- and long-term dryness here combined with lowering streamflows led to the expansion of abnormal dryness in central North Carolina. Short-term dryness also led to the expansion of abnormal dryness in parts of coastal South Carolina.
Midwest
Warmer than normal temperatures occurred over most of the Midwest region over the past week. Heavy rain impacted much of Minnesota and Illinois, while heavy rain was spottier in parts of Missouri, Iowa, Indiana, and Ohio. In several areas that missed out on heavier rainfall, conditions degraded. Extreme drought conditions expanded in northern Missouri into a small part of southeast Iowa, where long-term precipitation deficits and warm conditions led to degrading conditions. Short-term precipitation deficits caused moderate drought to expand in the Michigan Upper Peninsula. Short-term dryness also led to abnormal dryness developing in west-central Missouri. Precipitation deficits and high temperatures led to the development of abnormal dryness over parts of northern Ohio and the southern Michigan Lower Peninsula. Short-term dryness also was noted over localized areas of central and eastern Wisconsin, the latter of which saw conditions degrade to abnormally dry. Short-term dryness ended in most of western Minnesota after a heavy rain event.
High Plains
Warm conditions over the last week took place in eastern Nebraska, eastern South Dakota, and eastern Kansas. Warm temperatures also occurred over much of western Wyoming and the high plains of Montana. Moderate to heavy rain fell over roughly the eastern half of Wyoming, much of Nebraska (excluding the Omaha and Lincoln areas), and parts of South Dakota and central Kansas. Heavy rainfall Monday night prevented the introduction of abnormal dryness in south-central Nebraska and north-central Kansas, where some long-term precipitation deficits and groundwater shortages are present. Heavy rain this week in parts of central Kansas led to small areal improvements where severe and extreme drought conditions were present. Meanwhile, in areas that mostly missed the rain, short- and long-term deficits caused degradation of conditions. Exceptional drought was introduced in a small area of east-central Kansas, and extreme drought was introduced in the Kansas side of the Kansas City Metropolitan Area and in far southeast Kansas. Conditions remained mostly status quo in Montana and the Dakotas, with a minor improvement from moderate drought to abnormal dryness southwest of Denver, Colorado, due to heavy rain.
South
Generally warm conditions were found across the South during the last week. Scattered, generally disorganized areas of moderate to heavy rain fell over parts of Oklahoma, Texas (excluding central and south Texas), Louisiana, Arkansas, Tennessee, and Mississippi. Improvements in drought conditions occurred in parts of the Texas and Oklahoma panhandles, while drought expanded in other parts of the panhandles. Extreme drought developed over a small area of northeast Oklahoma as a result of short- and long-term precipitation deficits. Scattered heavy rain over north Texas led to changing drought conditions as many areas that received heavy rain saw improvements to their conditions. Heavy rain in southwest Texas also partially alleviated drought conditions. The hit-and-miss rains in Arkansas, Louisiana, and Mississippi led to small changes in areas of mostly moderate drought and abnormal dryness that were caused by short-term precipitation deficits. In western Tennessee, which mostly missed this week’s heavier rains, conditions continued to dry out in the short term, which may soon lead to abnormal dryness.
West
Very warm and generally dry weather occurred over the last week in California, Oregon, and Washington. Meanwhile, in southern Nevada, southeastern California, and parts of Utah and Arizona and New Mexico, scattered monsoonal rains continued, leading to localized heavy rains. Because of the short- and long-term precipitation deficits present in much of the region coming into this past week, large amounts of rainfall were needed for drought conditions to improve. Improvements in extreme and exceptional drought conditions occurred over parts of Arizona where enough rain fell to substantially reduce the ongoing deficits. Conditions in Washington continued to dry out in the short term. Combined with warm temperatures, this led to the development of moderate drought in the Olympic Peninsula and the expansion of abnormal dryness in parts of eastern Washington. Abnormally dry conditions also developed in parts of the Idaho Panhandle because of precipitation deficits and low streamflow.
Alaska, Hawaii, and Puerto Rico
In Puerto Rico, recent rainfall led to abnormally dry conditions improving on the southwest part of the island. In Hawaii, continued drier conditions on the Big Island led to the introduction of moderate drought. In Alaska, longer-term deficits built up enough over southeastern Alaska to degrade conditions to moderate drought there.
Looking Ahead
Over the next 5-7 days, the southern Plains and the Northwest are forecast to remain mostly dry. Rain chances will likely continue over the Southwest, though the focus of the heaviest precipitation will likely be from the mountains in Colorado and New Mexico northeastward into the southern and central High Plains. Rain is also forecast in the northern Plains and Upper Midwest. The best chances for heavy rain amounts during the next week will generally be east of the Mississippi River. The highest chances for warmer than normal temperatures over the next week will be in Alaska, New England, the Florida Peninsula, the Intermountain West, the Desert Southwest, and the Pacific Northwest. In between these areas, the greatest chances for cooler than normal temperatures will occur in the central and northern Plains and in the Upper Midwest.
Wildfires are happening.
And we do not want to ignore floods.
2. Last Week’s Weather
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.
Soil Moisture is a very important part of understanding drought.
3. Current Forecast for Precipitation.
And here is the drought forecast issued on July 19, 2018. it will be updated on July 31, 2018. It can be accessed here and here. It is confusing that there are two places to look one being a monthly update the other being a seasonal update but that is the way it is. But we are posting the latest version in our report each week. It is only updated twice a month.
The question is does that drought forecast fit with the weather forecast?
And now the forecasts. Here I provide the weather forecasts for different periods of time in July into 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 when it was updated today Friday July 20). This was important as the current Day 6 – 14 forecasts and the week old week 3 – 4 forecast overlap to some extent.
Here is another useful graphic from my weekly report.
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.
Worse than last year and or 5-Yr average | Better than last year or 5-Yr average | In line with recent conditions for this time of year or 5 – Yr Average |
Winter Wheat, Sorghum, Cotton, Pasture and Range Conditions | Corn, Barley, Oats, Soybeans, Spring Wheat, | Rice, Sunflowers, Peanuts, |
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 can be helpful to make text come alive.
I am now routinely including the precipitation report for Mexico since storms do not respect borders.
6. Prior Month and when available the Current Month-to date Weather (excluding prior week)
First here is the recent history:
First precipitation
And then temperature: and notice for temperature I am showing the temperature anomaly which is different than the above graphic where I show the actual.
You can generate a wide variety of different graphics here.
Last week we showed a lot of full-month June maps. We are not showing most of them this week but they can be found in last week’s article which can be accessed here. They tend to be issued in the second week of the following month so we provided them in the Drought and Agriculture Report that we issue when those graphics are first available. If we feel they are very useful, we carrying them for some number of weeks.
We believe that looking at how temperature and precipitation for a given month fits in the 124 year history can be very informative so we are showing this graphic again this week.
7. Science Theme When we Have One.
Texas is in drought and has a history of drought.
The following is a history of drought in Texas and actions taken to deal with drought.
Some selected dates on droughts and extreme weather from the TWRI timeline: |
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