September 13, 2018 Drought and Agriculture Report – Looking Much Better

Written by Sig Silber

Updated at 3:30 PM EDT September 14, 2018 to reflect the Update Week 3 – 4 Forecast

If the goal is for drought to impact only about 1/4 of CONUS at any point in time, we are making some progress. At the end of January of this year, 2/3 of CONUS was classified with some level of drought and this is now down to 50%. With significant improvement in the Great Plains, the main areas of concern now are the Northwest, Southwest and Far West. El Nino may cut the area of concern in half. We will see how that evolves. Since drought is to some extent defined relative to climatology, it is not realistic to be drought free all of the time. What is normal for vegetation adapts to climatology so deviations from climatology are recorded as being more or less favorable. With two low-frequency cycles, the PDO and AMO impacting CONUS weather, periods of a drought tendency are inherent in the climate of CONUS.

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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

This map which covers only a part of  this area may be useful also.

The following graphics are easier to interpret because the week to week changes are shown but are less attractive and do not show the drought classification but rather the change in the classification..

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

Deterioration in North Dakota

Mostly general improvement; especially Missouri.

Mostly Improvement in the Northeast

Substantial Improvement

Not much change overall

Mixed with some improvement in Arizona and New Mexico and some deterioration in the Northwest and Southern California

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

A stalled cold front draped across the southern Plains, middle Mississippi and Ohio Valleys, and mid-Atlantic, plus ample Gulf moisture from Tropical Storm Gordon, was the focal point for moderate to heavy showers and thunderstorms. Widespread amounts of 2-4 inches, with locally 6-12 inches, were common in the southern and central Great Plains, along the Gulf Coast (Gordon), in the lower and middle Mississippi, Tennessee, and Ohio Valleys, western Great Lakes region, and the mid-Atlantic. Similar to last week, additional improvements were made in the Midwest, but this week, major modifications (improvements) were also done in the southern Plains (especially Texas) and lower Mississippi Valley. Elsewhere, little or no precipitation fell across the western third of the Nation, although some light showers finally dampened western Washington. In addition, the northern Plains, parts of the Southeast (Georgia and Carolinas), and extreme northern New England saw little or no rain. Temperatures averaged below-normal across the middle third of the Nation and in New England, and above-normal in most of the West, Southeast, and mid-Atlantic.

Northeast

After the first 6 days of the period saw little or no precipitation across most of New England and degradation looked probable, Day7 brought widespread light to moderate rains (1-2.5 inches) to the drought and abnormally dry areas of upstate New York, Vermont, New Hampshire, and coastal Maine. Decent rains (1-2 inches) also fell on far western New York (near Buffalo) during Day6. As a result, short-term deficits were reduced enough to allow for some 1-category improvements in western New York, the southern sections of the drought area in upstate NY, Vermont, and New Hampshire, and along coastal Maine, with the latter area’s recently introduced D2 improved to D1, and the former D1 area shrunk. USGS 1- and 7-day averaged stream flows responded to the rains, rising into the near normal category except for far northern locations that received lower amounts and stayed in the 10th (much below) to 24th (below normal) percentile. In contrast, little or no rain was reported in far eastern Maine (Aroostook county) where 30- and 60-day precipitation was below normal along with low 7-day averaged stream flows, thus the two separate D0 areas in eastern Maine were merged. The D0 in eastern Massachusetts remained unchanged as enough rain fell (~1 inch) to prevent deterioration, but not enough for D0 removal with shortages remaining at 30-, 60-, and 90-days.

Southeast

Except for localized heavy rains from Tropical Storm Gordon (which made landfall near the MS-AL border), much of the Southeast saw little or no precipitation through Day6. On Day7 however, scattered showers and thunderstorms (0.5-2 inches) developed over parts of the central Carolinas and eastern Georgia, dropping enough rain to keep conditions status-quo in the Carolinas (still 2-5 inch deficits at 60-days), but erasing shortages in eastern Georgia, thus D0 was removed there. In east-central Georgia, however, little or no rain fell, and D0 was slightly expanded to depict the growing 60-day departures of 1-3 inches. Farther west, Gordon dropped a narrow band of 4-12 inches of rain from the extreme western Florida Panhandle northwestward into east-central Mississippi and west-central Alabama, erasing D0 in the latter two areas, and in Baldwin County in southern Alabama. Just to the east, however, scattered, lighter precipitation occurred, producing 60-day deficits of 2-5 inches that resulted in some D0 expansion and new D1 areas in northern Alabama, northern Mississippi, and southwestern Tennessee.

South

Moist inflow from the western Gulf and a stalled cold front across the south-central Plains triggered widespread, numerous showers and thunderstorms across much of Texas into central Oklahoma, along with bands of heavy showers across most of Louisiana. The remnants of Gordon also dropped spotty but heavy amounts of rain on parts of Arkansas, Mississippi, and western Tennessee (see Southeast). About the only area in the South that missed out on decent rains were eastern Oklahoma, western Arkansas, and the northern Texas and western Oklahoma Panhandles. With widespread weekly totals of 4-8 inches and locally more, much of southern, central, western, and southeastern Texas saw 1-2 category improvements as most station SPIs were normal or wet at 2-, 3-, and 6-months, and even 12-month SPIs were improved. Average 1-, 7-, and 14-day USGS stream flows responded into the 76th (above normal) or 90th (much above) percentiles where the improvements occurred. In Oklahoma, 1.5-6 inches of rain allowed for a 1-cat improvement in parts of southwestern, south-central, and northeastern Oklahoma. In Louisiana, scattered showers and thunderstorms (1.5-4 inches) continued this week as a wetter pattern has gradually improved conditions, although a few dry pockets of D2-D3 remained in the northwest. In Arkansas, rain across the southern, northern, and eastern portions of the state eroded some of the previous week’s D0 and D1. 1-cat improvements were also made in parts of northwestern Mississippi and western Tennessee as Gordon rains dropped 2-5 inches.

Midwest

For the third consecutive week, large portions of the Midwest were inundated with heavy rainfall (2-8 inches), although this week the greatest rains fell along the Ohio River Valley after missing out the previous 2 weeks. Due to these rains, a 1-cat improvement was made in parts of the Missouri Bootheel, western Kentucky, southern Illinois, southwestern Indiana, and northern Ohio. Moderate to heavy rains also fell on portions of the middle Mississippi and lower Missouri Valleys, although it was more scattered in nature, producing bands of improvement where the greatest totals (2-6 inches) fell. A band of moderate to heavy rain (2-6 inches) also fell from southeastern Minnesota northeastward into the UP of Michigan, erasing a few small D0 areas in central Wisconsin and Michigan’s Luce and western Chippewa Counties. Lighter totals (0.5-2 inches) were reported in lower Michigan, but with last week’s rainfall, 30- and 60-day deficiencies were vanquished, leaving only smaller 90-day deficits. Thus, some 1-cat improvements were made to the D0 and D1 areas where the 1- and 2-month shortages were erased. The rains have steadily improved growing conditions as the Aug. 12 USDA/NASS report of pasture conditions for IA and MO were 28 and 76% poor or very poor; by Sep. 9, those values had dropped to 17 and 44%, respectively. In contrast, D0 was expanded in northern Minnesota (Cass and Hubbard Counties) in areas that missed out on the decent rains the past 30 days and USGS stream flows dropped below into the 10-24th percentile, while D1 was added to Lake of the Woods and western Koochiching Counties with 90-days deficits of 2-4 inches and very low stream flows.

High Plains

Generally little or no precipitation fell across the western High Plains while light rains (0.5-1 inch) fell on parts of North Dakota, southeastern South Dakota, eastern Nebraska, most of Kansas, and central Colorado. Scattered locations in extreme southeastern SD, northeastern NE, and eastern KS received more (1.5-3 inches, locally to 7 inches in southeastern KS), but most of this rain fell on non-drought areas. An exception to this was north-central and southeastern Kansas where a 1-cat improvement was made, but unfortunately missed most of the core D2-D4 area in northeastern Kansas (again). Kansas pastures and ranges have also improved, with a NASS/USDA Aug. 12 value of 35% poor or very poor versus a Sep. 9 value of 20%. Subnormal weekly temperatures (anomalies of -2 to -6 degF) in the central Plains also eased evaporative demands. In contrast, drier and warmer weather in the Dakotas have steadily lowered moisture and growing conditions. Under half of normal 30- and 60-day precipitation has fallen on parts of North and South Dakota, and field reports are indicating declining farming, ranching (no forages to graze), and hydrologic (shallow wells and small ponds drying up) conditions. The NASS/USDA poor and very poor pasture conditions for ND and SD have slowly climbed from 7 and 10%, respectively, on July 29, to both at 25% on Sep. 9. Accordingly, D0-D2 was expanded into the driest areas, and a D3 was added in McHenry County, ND, where the field reports and drought tools lined up.

West

Warmer weather returned to the Northwest after two consecutive weeks of near or subnormal temperatures. Deteriorations in this week’s dry areas were limited to an expansion of D1 into central Washington’s Chelan and Kittitas Counties (2, 3, and 4-month SPEIs -1 to -1.5); a slight increase in D3 in Oregon’s northern Harney and Malheur Counties (soil moisture models, EDDI > 6 weeks, Vegetation Health, VegDRI, low stream flows); reassessment of northern California (D0-D2 shifted eastward into Siskiyou and Modoc Counties); D2 expanded into southern Idaho (Oneida County) with similar conditions in bordering northern Utah (Box Elder County); D3 expanded in southeastern CA due to the weak to non-existent summer monsoon rains. In contrast, improvements were made in central Arizona (courtesy of the Flagstaff WFO) that noted the past 8 weeks have seen well above-normal monsoon rains (in some areas 40-70% of average ANNUAL rainfall) in central Yavapai County and the Mogollon Rim region; and in eastern New Mexico that received significant rains (but less than neighboring west Texas) – with some improvements to Colfax and Mora Counties [D3 to D2], San Miguel and Guadalupe Counties [D2 to D1], DeBaca and Chavez Counties [D3 to D2], and Roosevelt County [D1 to D0]. Conversely, some D2 was added into eastern Otero County, NM, and northeastern Hudspeth County, TX, after a reassessment of conditions. The rest of the West was left untouched as the Pacific Northwest awaits the start of its wet (Fall) season.

Alaska, Hawaii, and Puerto Rico

Based upon the full set of August rainfall and FSA input, adjustments were made to the Big Island and Maui depictions. In the Big Island, the districts of Kau and South Kona improved from D1 to D0, and sufficient rainfall occurred on the slopes of the North Kona and South Kohala districts for a D2 to D1 change; however, lower elevations received much less rain, and were left unchanged. In Maui, the area from Maalaea to Kihei measured surplus monthly amounts and improved from D2 to D1, but the lower leeward slopes of the West Maui Mountains received far less rain and remained at D2. The rest of the islands were status-quo.

In Puerto Rico, heavy showers (2-8 inches) fell across the northwestern interior quarter of the island, with lesser totals (1-2.5 inches) measured in the northeast and southeast. Little or no rain fell along most of the immediate southern and northern coasts, and in the east-central interior. Based upon the past 7-, 60- and 180-day departures, the D0 area was removed in the north-central region, and expanded slightly into southeastern sections.

In the southeastern Alaskan Panhandle, the areas of D0 and D1 were left unchanged as light to moderate weekly totals (1-3 inches) were not large enough to remove longer-term deficits (where the SPI for climate division 12 was in the moderately dry or worse category for most periods from 2-36 months), but not small enough for deterioration. This area is moving into its wet season, which says how much precipitation this part of Alaska typically gets. Some locations have WYTD (since Oct. 1, 2017) deficits of more than 30 inches, and stream flows are below normal as many salmon return this time of year.

Looking Ahead

For the ensuing 5 days (September 13-17), the focus will be on Hurricane Florence’s landfall and where it tracks thereafter. As of Wednesday afternoon, the most likely scenario is landfall near the NC-SC border, with the hurricane slowing down and dropping catastrophic amounts of rain (over 20 inches near landfall), with possible devastating floods in parts of the Southeast and mid-Atlantic. The 5-day QPF targets the Carolinas and Virginia with 4-10 inches, with heavy rains moving northward into the Northeast during Days 6-7. Elsewhere, a tropical disturbance is expected to move into the western Gulf from the Caribbean, dumping more heavy rain (2-6 inches) on the southern half of Texas. Pacific systems traversing along the US-Canada border may drop light to moderate amounts from Washington to Minnesota. Little or no precipitation is expected elsewhere. Temperatures should average below-normal in the Far West, northern Rockies, and Texas, and above-normal from the Southwest northeastward into New England.

For the CPC 6-10 day extended range outlook (Sep. 18-22), the odds favor above-normal precipitation in the northern half of the Plains, in the eastern quarter of the country (from Florence), and northwestern Alaska. Chances are good for subnormal precipitation in most of the West, south-central Plains, lower and middle Mississippi Valleys, and southern Alaska. Above-normal temperatures are likely in the southern and eastern sections of the U.S. and most of Alaska, with subnormal readings limited to the Northwest and northern Rockies and Plains.

Wildfires are happening.

Current wildfire forecast

The below are the forecasts by month for wildfires.

Additional information can be found here.

And we do not want to ignore floods.

Reservoirs

We provided this information recently and I have not updated these two graphics as they change slowly.

This article provides a little background on the problem.

The above were not updated but we have added two more rivers to the discussion. Above we have reservoirs and they are of course connected by rivers. Both are important and provide insight.

Let’s take a closer look at the Intermountain West which is one of the remaining problem areas. This provides a good way of looking at precipitation over different time frames.

But here is another way of looking at it.

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.

 Here is another way to look at the evaporation.

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 4.
The number of states with Topsoil (near surface) surpluses has increased by 7 from last week and the number of states with Subsoil (subsurface) surpluses has increased by 4. 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 Month of September Forecast Issued on August 31 and then the  Seasonal Forecast through November which was issued on August 16 with the full Seasonal Outlook. 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 here is the longer seasonal drought forecast.

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 will update the discussion for the Week 3 – 4 forecast when it is updated on Friday August 31). 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. When we publish Thursday night, the Week 3 – 4 forecast is a week old but it then updates on Friday and we have now updated the discussion accordingly.

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 and deamplifying pattern. In general is will be wamer than climatology for the Southern Tier.		↑ ←  The Week 3 – 4 forecast will be updated on Friday September 14. A warm West which does not help those drought areas.

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.	This forecast changed today so will will see if it flips back to what has been forecast in recent days. As shown, it looks pretty good re drought for all of CONUS other than the Northwest.		↑ ←  The current Week 3 – 4 forecast will be updated on Friday September 14. The Precipitation Pattern is bad for the Northwest, good for Arizona and not good for most of the Intermountain Region and Central and Eastern NM and Western Texas and the western part of some of the states north of Texas. But this is the Week 3 – 4 forecast only.

The Week 3 – 4 forecast is always updated the day after we publish our drought and agriculture report so it is our practice to update that report on Fridays to reflect the updated Week 3 – 4 report. We have done that on September 7, 2018

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

The below is of interest.

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.

* Close to completion for this years crop  and 2018 planting has begun or soon will

5. International Crop and Weather Related Information

Sometimes a map is useful.  it was not updated this week.

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

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

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

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

First Precipitation

And then temperature:

You can generate a wide variety of different graphics here.

Looking back at August

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