September 26, 2019 Weather Impacts On Economic Activity – Flash Drought

Written by Sig Silber

Updated at 8 p.m. EDT September 27, 2019 to reflect the newly issued Week 3 – 4 forecast which is a bit more favorable for the corn, soybeans and other crops.

This past week has been characterized by widespread “Flash Drought” due to late-summer heat. The impact of Flash Drought was magnified by a high percentage of poorly developed root systems due to late Spring frozen ground followed by extensive flooding. Assessing Flash Drought is not easy so we will pay attention to next week’s Drought Monitor Report to see if there have been a lot of adjustments to what was reported this week. This week, we also report on record-high soybean production in China and a devastating drought in Zambia and Zimbabwe as well as reports from Russia, Kazakhstan, the EU and Australia.

Each week we report on the current status of the crop and once a month, or as the data comes in, we report on the forecast of the final seasonal results. And we have many other regular drought-related indices we report on including wildfires and floods and soil conditions. We also provide a shortened version of the Intermediate-term weather forecast.

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China Soybean Production Up. (This report is a bit old dated (August 29, 2019)

China Soybeans: 2019/20 Production at a Record HighChina’s 2019/20 soybean production is forecast at a record high primarily due to a rise in area planted, which is at a 5-year high. USDA forecasts production at 17 million metric tons (mmt), up 1.1 million from last year. This season’s production is roughly 7 percent higher than last year’s record crop of 15.9 mmt (Figure 1). Area is forecast at 9.1 million hectares, up 0.7 million or 8.3 percent from last year. From 2009 to 2015 China’s soybean production declined significantly due to substantial area decreases. However, the trend has since turned around beginning in 2016. According to China’s National Development and Reform Commission (NDRC), the change is due primarily to farmers’ response to the government enactment of strong agricultural support policies including high minimum prices, guaranteed purchases, and production subsidies. In addition, in 2014 the government introduced a series of agricultural policies aimed at managing the domestic corn market, reducing corn inventories, and preventing stockpiles from increasing further. Farmers have significantly expanded soybean area for the past 5 years while decreasing planted corn area (Figures 1, 2). Yield is forecast at 1.87 tons per hectare (t/ha), down 1 percent from last year, but up 2 percent from the 5-year average of 1.83 t/ha. The year-to-year yield decrease is due primarily to drier-than-normal soil moisture conditions during the early part of the growing season (May-June), especially in the central China plains (Figure 3). These conditions slowed planting and early plant establishment. Overall, however, the 2019/20 season has progressed well across the major soybean growing regions with bumper crops expected. Favorable weather conditions continued to prevail mid-to-late season. Satellite-derived data and other observations indicated that June and July soil moisture ranged from adequate-to-abundant, resulting in favorable crop growth and development. The soybean crop is currently in advanced reproductive-maturity stages, as indicated by crop model indicators. Harvest typically begins in late September in the North China Plains and in the Northeastern provinces. About 50 percent of China’s soybeans are grown in the Northeast provinces of Heilongjiang, Jilin, and Inner Mongolia. Heilongjiang province alone accounts for about 40 percent of the national soybean output. Other major provinces include Anhui, Henan, and Shandong (Figure 4)

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Now let us take a look at Three-month temperature and precipitation rankings. We have previously reported on August only rankings. Now we have the data for June through August.

And shifting to the Alaska and CONUS Weather Forecast

First Temperature

And then Precipitation

Concluding remarks

Here is the discussion that was released with the Week 3 – 4 Forecast issued today.

Week 3-4 Forecast Discussion Valid Sat Oct 12 2019-Fri Oct 25 2019

ENSO-neutral conditions currently are present across the equatorial Pacific Ocean. Equatorial sea surface temperatures (SSTs) are above average across the western Pacific Ocean and are below average in the eastern Pacific. The RMM MJO index indicates the enhanced convective phase of the MJO moving across the Western Hemisphere and Africa. The Week 3-4 Outlook is based primarily on dynamical model forecasts, including the NCEP CFS, ECMWF, and JMA ensemble prediction systems, as well as the Subseasonal Experiment (SubX), a multi-model ensemble (MME) of both operational and experimental ensemble prediction systems. Statistical forecasts, including a multivariate linear regression (MLR) of lagged temperature and precipitation forecasts to current observed MJO and ENSO indices, are also consulted. Decadal timescale temperature trends are also a source of predictability in both dynamical and statistical forecast tools.

Dynamical model guidance from the various models is broadly consistent, depicting a trough near the West Coast with downstream ridging over the east-central CONUS. The CFS, ECMWF and JMA models indicate positive 500-hPa heights anomalies over the eastern CONUS, while near to below normal 500-hPa heights are favored over most of western CONUS. Both the ECMWF and JMA favor near to above normal 500-hPa heights over most of mainland Alaska, while the CSF indicates below normal 500-hPa heights over the mainland Alaska. All tools (CFS, ECMWF and JMA) indicate near or above normal 500-hPa heights over Hawaii.

The Weeks 3-4 outlook indicates enhanced probabilities of below normal temperatures over the Pacific Northwest, parts of the Northern Great Basin, northern California, and northern Nevada, while above normal temperatures are favored over most of the eastern and central CONUS, New Mexico, and Arizona, consistent with the majority of the guidance. Equal chances forecast across New England is due to the expectation of a variable temperature pattern during this two week period. Above normal sea surface temperatures in the Bering Sea, decadal temperature trends, and predicted ridging over the Aleutian Islands leads to elevated probabilities of above normal temperatures for Alaska, supported by the CFS/ECMWF/JMA Correlation Weighted tool.

The precipitation outlook for the week 3-4 period presented several challenges, as variations among the ECMWF, CFS and JMA operational ensembles and among the constituent models of the SubX indicate uncertainty following the week 2 period. The Weeks 3-4 outlook indicates likely above median precipitation for Florida Peninsula, parts of the Northern and Central Plains, and the Upper and Middle Mississippi Valley, which is consistently highlighted by model guidance. There are enhanced probabilities of below normal precipitation across the Pacific Northwest, parts of the Northern Great Basin, northern California, and northern Nevada, where dynamical models are in general agreement. Below median precipitation is also more likely for parts of the Ohio Valley, the Tennessee Valley, Mississippi, and Alabama, supported by the CFS/ECMWF/JMA correlation weighted tool. Above median precipitation is likely for areas of the Aleutians and western Alaska, due to onshore flow ahead of anomalous above normal sea surface temperatures.

Observed well above normal sea surface temperatures and dynamical model guidance from the SubX suite strongly support above normal temperatures during the Weeks 3-4 period across Hawaii. A consensus of the SubX dynamical models predicts likely above normal precipitation for the Hawaiian islands.

Here is another way of looking at it:

Current Drought Conditions

Now we take a look at Thursday’s U.S. Drought Monitor Report.

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.

U.S. Affiliated Pacific Islands and the U.S. Virgin Islands.

Below is the map for just CONUS.

Last Week	This Week

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

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

Now we show the week to week change information by region. The yellow is where the level of drought has been raised. The green is where the level of drought has been lowered.

Deterioration in Colorado. Some deterioration in Kansas.

Improvement to the north and deterioration to the southeast. The states with the worst deterioration are Ohio, Indiana, and Kentucky,

General deterioration.

Mixed in Texas, Improvement in Oklahoma, Deterioration to the east especially Tennessee, Mississippi and northern Louisiana.

General deterioration but with respect to Florida it was only northern Florida and for North Carolina it was the western part of the state.

Colorado is the focus of the deterioration. The improvement is in the Northwest but it extends east quite a bit.

Focusing on the Southwest Region

Here is the Discussion that was issued with the Drought Report.

This Week’s Drought Summary

Rapidly intensifying “flash drought” – attributed in part to extreme late-summer heat – continued to afflict many areas from the lower Midwest and Mid-Atlantic States to the Gulf Coast. Conversely, heavy to excessive rainfall associated with the remnants of Tropical Storm Imelda eradicated drought but caused locally catastrophic flooding in southeastern Texas and western Louisiana. Farther west, late-season showers on the heels of an abysmal Southwestern monsoon (to-date) helped stem drought increases in the Four Corners region, while rain and mountain snow further reduced lingering drought in the northwestern quarter of the nation. Meanwhile, additional moderate to heavy rain eased or alleviated dryness and drought from the Northwest into the Great Lakes. Outside of the lower 48, additional heavy rainfall eased lingering drought and dryness in south-central Alaska. Elsewhere, short-term drought persisted across the Hawaiian Islands, while Puerto Rico was mostly dry; rain arrived in Puerto Rico after the monitoring period ended (Tuesday morning).

Northeast

Despite the arrival of somewhat cooler conditions in parts of the Northeast, the overall trend of warmer- and drier-than-normal weather continued to exacerbate short-term dryness and drought in the region. Abnormal Dryness (D0) and Moderate Drought (D1) increased from West Virginia and Maryland northeastward into southern New England. Acute short-term rainfall deficits (30-day rainfall totaling 10 to 50 percent of normal, locally less than 5 percent in southern portions of the region) led to the expansion of D0, while similar deficits out to 60 days – coupled with vegetation stress and declining streamflows – led to a notable increase of D1 across the southern tier of the region.

Southeast

Another round of late-summer heat and persistent acute short-term dryness led to a sharp increase in drought intensity and coverage. Triple-digit daytime highs and pronounced short-term rainfall deficits (60-day rainfall totaling less than 40 percent of normal) heightened evapotranspiration rates and soil moisture losses, resulting in quickly escalating drought impacts (often referred to as a “flash drought”.) It should be noted that “flash drought” impacts often materialize more quickly than the precipitation data indicates due to the heat. For this weeks’ analysis, the expansion of D0 (Abnormal Dryness) and Moderate to Severe Drought (D1-D2) was driven in large part by guidance from local experts, impact reports from observers, as well as temperature- and rainfall-driven data products which focused on the past 30 to 90 days. Increases in D0, D1, and D2 were most pronounced in northern portions of the region (from northern Alabama into central North Carolina) as well as from northern Florida (including the panhandle) into southern Georgia. Severe Drought areas (D2) are mostly coincident with 90-day rainfall less than half of normal, with some locales lower than one third. Furthermore, a small pocket of D3 (Extreme Drought) in northeastern Alabama is likely a harbinger of things to come if rain does not materialize soon. As of September 22, state-wide average topsoil moisture ratings (according to USDA-NASS) continued to tank; double-digit jumps week to week in percent rated poor to very poor were noted in North Carolina (60 percent poor to very poor, up 18 percentage points from last week), South Carolina (77 percent, up 25 points), Georgia (88 percent, up 15 points), and Alabama (highest in the region at 91 percent poor to very poor, up 18 percentage points from last week. Even Florida noted a 12 point jump from last week, and was now averaging 37 percent poor to very poor.

South

Highly variable conditions were observed across the South, with intense late-summer heat and acute short-term dryness in southwestern and northeastern portions of the region contrasting with heavy to excessive rainfall across the west-central Gulf Coast and from western Texas northeastward into central and southern Oklahoma. Tropical Storm Imelda moved slowly ashore near Freeport, Texas, drifting northward while producing prodigious rainfall totals (20-30 inches, locally more) south and east of Houston. Heavy rain (2-8 inches) was also noted further inland across eastern Texas, western Louisiana, and southeastern Oklahoma, easing or alleviating Abnormal Dryness (D0) as well as Moderate to Severe Drought (D1 and D2). Farther west, widespread heavy showers (1-5 inches, locally more) from Texas’ Big Bend northeastward into central and southeastern Oklahoma (a peak value of 7.66 inches was noted in Antlers, OK) likewise supported aggressive reductions to drought intensity and coverage.

Conversely, excessive heat (daytime highs approaching or topping 100°F) and pronounced short-term dryness (60-day rainfall totaling locally less than 20 percent of normal) heightened evapotranspiration rates and soil moisture losses, resulting in quickly escalating drought impacts (often referred to as a “flash drought”.) It should be noted that “flash drought” impacts often arise more quickly than the rainfall data would suggest due to the accompanying heat. For this week’s analysis, the expansion of D0 (Abnormal Dryness) as well as Moderate (D1) to Extreme Drought (D3) was driven by guidance from local experts, impact reports from observers, as well as temperature- and rainfall-driven data products which focused on the past 60 to 90 days. Increases in drought were most pronounced from the Rio Grande toward Dallas, Texas, and from the central Delta into Tennessee. State-wide average topsoil moisture was rated more than 70 percent short to very short (according to USDA-NASS) as of September 22 in Arkansas (78 percent poor to very poor), Mississippi (83 percent), and Tennessee (89 percent, a 14-point jump over last week).

Midwest

Additional reductions to drought intensity and coverage across the northern half of the region contrasted with rapidly intensifying and expanding drought in the south. From Iowa into Michigan (including northern portions of Illinois and Indiana), another widespread soaking rainfall (1-6 inches) eased or eradicated lingering Abnormal Dryness (D0) and Moderate Drought (D1). Conversely, temperatures in the middle 90s coupled with acute short-term moisture deficits (60-day rainfall locally less than 30 percent of normal) led to an expansion of D0 and D1 as well as the introduction of Severe Drought (D2), most notably from southern Illinois eastward into Kentucky and neighboring portions of Indiana and Ohio. State-wide average topsoil moisture was rated 55 percent short to very short (according to USDA-NASS) as of September 22 in both Indiana and Ohio, and 86 percent poor to very poor in Kentucky. Reports from the field indicate Kentucky is experiencing the same type of “flash drought” being observed across much of the south; the impacts of “flash drought” often occur more quickly than the objective data indicates.

High Plains

Most of the region remained free of drought, as above-normal temperatures in the east contrasted with cool albeit dry conditions in the west. However, Abnormal Dryness (D0) and Moderate Drought (D1) were increased in parts of southwestern Kansas as well as south-central and western Colorado due to increasingly dry conditions over the past 90 days (30-50 percent of normal).

West

Moderate to heavy showers arrived in the Southwest, while unsettled, cool conditions continued across the Northwest.

Showers and thunderstorms (1-4 inches, locally more) associated in part with moisture from the remnants of Hurricane Lorena arrived in central Arizona, helping to stem further drought increases (at least temporarily) from the abysmal Southwestern monsoon season-to-date. Despite this week’s showers, 6-month rainfall has totaled a meager 10 to 50 percent of normal, with higher totals (70-100 percent of normal) noted in the mountains of central Arizona. The Southwestern monsoon typically runs from June 15-September 30 and accounts for up to half the total annual precipitation in some parts of the Southwest.

Farther north, near- to below-normal temperatures as well as another round of moderate to heavy rain (1-3 inches) from the Pacific Northwest into the northern Rockies spurred additional reductions of Abnormal Dryness (D0) and Moderate Drought (D1). At week’s end, D0 and D1 were limited to locales still reporting longer-term precipitation deficits (12-month precipitation averaging near 75 percent of normal or less).

Alaska, Hawaii, and Puerto Rico

The recent wet weather trend continued in Alaska, with this past week featuring 1 to 3 inches of rain over many of the state’s primary drought areas. 7-day rainfall totaled as much as 3.92 inches on the Kenai Peninsula, pushing the two-week rainfall to more than 8 inches locally. While more rain will be needed to fully eradicate the Alaska’s Moderate to Extreme Drought (D1-D3), the recent wet weather has eased the drought coverage and intensity in the south and southwest. In Hawaii, portions of the Big Island and Maui remained very dry. In particular, South Point on the Big Island was increased to Severe Drought (D2) to reflect the very poor vegetation health signal depicted in satellite imagery. It was a quiet week in Puerto Rico, with heavy showers approaching after the end of the drought monitor period (ending 12z, Tuesday morning).

Pacific Islands

The weather pattern during this USDM week (9/18/19-9/24/19) was dominated by a two main features: a surface ridge which continued across southern portions of Micronesia for most of the week, and a monsoon trough during the last half of the week which stretched from the Marianas eastward to the northern Marshall Islands (RMI), keeping just north of the Federated States of Micronesia (FSM). Weak circulations populated the monsoon trough, while an upper-level low or trough near the Marianas enhanced precipitation. South of the equator, a strong high pressure ridge kept its grip over the Samoan Islands, keeping a surface trough to the north of the islands for most of the week; the trough advanced to the islands as the ridge shifted away at the end of the week.

Satellite-based estimates of 7-day precipitation (QPE) showed areas of 2+ inches of rain across parts of the Marianas and northern RMI, and brushing the northern edge of Chuuk and Pohnpei States and northwest Yap State. The QPE tapered off to no rain for the week across southern portions of Micronesia. A band of 2+ inches of rain was evident north and east of the Samoan Islands, with 0.5 to 1.0 inch brushing American Samoa, and mostly no rain to the southwest.

With 0.86 inch of rain, Palau had less than the 2-inch weekly minimum for a second consecutive week, but previous weeks and months were wet, so D-Nothing continued.

The combination of monsoon trough, surface disturbances, and upper-level low/trough gave the Marianas another wet week (more than the 1-inch weekly minimum needed to meet most water needs). Weekly rainfall totals ranged from 2.45 inches at Dededo and 2.53 inches at Guam to 3.66 inches at Saipan and 4.13 inches at Rota. The ASOS station at Saipan recorded 4.52 inches for the week and the automated NPS station at Saipan recorded 3.14 inches. With well over a foot of rain for the month so far at the regular-reporting stations, D-Nothing continued region-wide.

In the FSM, Fananu has been missing for the last two weeks, and Ulithi continues to be missing, so an analysis could not be made for these two locations. Yap had more than the 2-inch weekly minimum needed for most water needs (2.62 inches), but the rest of the stations in the FSM were dry, some with no rain reported for the week. The zero-inch stations included Kosrae, Kapingamarangi, Nukuoro, and Pingelap. However, D-Nothing continued across the FSM because this was only the second consecutive dry week, at the longest, and previous weeks and months were wet. But if the dry conditions at the southern stations continue, D0-S may be considered in the next week or two.

In the RMI, eastern stations were wet (Utirik 3.57 inches, Wotje 2.08, Mili 2.09) while other stations were dry (less than the 2-inch weekly minimum). Ailinglapalap and Jaluit measured no rain this week. With preliminary reports of some rain catchments getting very low, D2-SL continued at Jaluit, and since this was only the second consecutive dry week at Ailinglapalap, D-Nothing continued there for now. But with zero inches measured this week and 4 of the last 5 weeks dry, if dry conditions continue for the next week or two, D0-S may be re-introduced at Ailinglapalap. D1-SL continued at Wotje this week. With 7 of the last 8 weeks wet and 11.33 inches of rain so far this month, Utirik had the sixth wettest September (so far), compared to 15 full Septembers, and the third wettest (out of 13 years) August-September, so the USDM status was changed from D0-L to D-Nothing at Utirik. With 0.74 inch of rain this week, the reservoir level at Majuro steadily declined during the week, reaching 74% of maximum by the 24th. This is below the 80% threshold of concern, but the monthly total (so far) of 8.38 inches is above the monthly minimum needed to meet most water needs, so D-Nothing continued. Mili was wet this week, and Kwajalein has a September total near the monthly minimum, so D-Nothing continued.

Rain on the last day of the week kept this week from being the fifth consecutive dry week at Pago Pago. Weekly rainfall totals included 2.08 inches at the Pago Pago airport, 2.35 inches at the automated station at Siufaga Ridge, and 1.29 inches at the automated station at Toa Ridge. But September (through the 24th) has been dry (only 3.86 inches of rain at the airport), ranking as the 13th driest September (compared to full Septembers) in 54 years of data and having a historical percentile of 0.24 (which is in the D0 range), so D0-S continued at Tutuila.

Virgin Islands

Wet and dry weather features alternated across the U.S. Virgin Islands (USVI) during this USDM week (9/18/19-9/24/19). The week began with a dry air mass laden with Saharan dust; a tropical wave passed south of the islands across the central Caribbean while Hurricane Jerry passed to the north. Feeder bands generated by Jerry brought areas of rain to the region, but amounts were only a few tenths of an inch. A mid- to upper-level high pressure ridge moved over the area at mid-week, bringing drier air to compete with the outer bands from the departing Jerry. Tropical Storm Karen was approaching the region from the south as the week ended, and Karen’s outer rain bands brought rain to the USVI overnight Monday into Tuesday morning, with much more rain to come after the 12z Tuesday USDM cutoff time.

Radar-based estimates of rainfall for the 7 days ending at 12z on Tuesday depicted areas of 0.5 to 2.0 inches of rain across parts of St. Croix and St. Thomas, with 0.5-1.0 inch over St. John.

The Henry Rohlsen AP had almost an inch (0.91) of rain this week, while the Christiansted 1.8 ESE CoCoRaHS station measured 2.49 inches, thanks to rain bands from Tropical Storm Karen, so St. Croix was wet. The monthly total at Rohlsen AP was 1.34 inches, which is below normal, but the monthly total at Christiansted was 5.42 inches. The well level at Adventure 28 has held steady for the last couple weeks, so the rain appears to have stopped its decline. The Standardized Precipitation Index (SPI) values still indicate dry conditions at the 1-, 9- and 12-month time scales, but they were computed before Karen’s rains fell. Based on the radar and CoCoRaHS reports, the D0-L on St. Croix was changed to D-Nothing.

The Cyril E King AP station reported 1.41 inches of rain this week, of which 1.23 inches fell on the 24th which was a record for the date. The total for the month so far was 2.33 inches, which is about half (53%) of normal, and the total for the year of 25.26 inches was about normal (103%). Data for the CoCoRaHS station at Anna’s Retreat went through only September 22nd, and so did not include rains from Tropical Storm Karen. The Grade School-3 Well level continued at relatively high levels, and even showed a slight increase in the last day or two. The SPI values at King AP were neutral to wet at all timescales. As a result of these indicators, D-Nothing continued on St. Thomas.

Data for the unofficial station at Windswept Beach went through September 23rd, so the rains from Karen were not included. Rainfall totals for the week through the 23rd were 0.08 inch and for the month 1.55 inches, which is below the long-term average. SPI values were neutral (not wet and not dry) at all timescales. The USGS Susannaberg DPW 3 Well level showed recovery at the end of August and has been fairly steady since then. As a result, D-Nothing continued on St. John.

Looking Ahead

The overall theme of a persistent and stagnant weather pattern will continue into next week. High pressure will maintain dryness and drought from New England to the Gulf Coast Region, though a series of weak cold fronts may provide chances for much-needed shower activity from eastern portions of Kentucky and Tennessee to the central Atlantic Coast. Likewise, mostly dry weather is expected from the Southwest into the central Rockies and Great Plains. In contrast, wet weather will continue from the Northwest into the northern Plains and upper Midwest, with another ribbon of moderate to heavy rain (locally more than 2 inches) possible from the southern High Plains into the Great lakes Region. The NWS 6- to 10-day outlook for October 1 – 4 calls for above-normal temperatures across the eastern half of the nation in addition to the southern Plains and western Gulf Coast region, while cooler-than-normal weather prevails from the Pacific Coast into the upper Midwest. Near- to above-normal precipitation across much of the nation will contrast with drier-than-normal conditions across the southeastern quarter of the nation.

.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 demise. When you read these graphics, remember that the older graphics are not the drought conditions that existed then but the change from then until now.

Let’s focus on the change between August 27, 2019 through September 24, 2019 i.e. a month. .

Drought Forecasts

First, we show the forecast through December which was issued on September 19, 2019 (to be updated on October 18, 2019). These two forecasts are issued by the same agency but to obtain them you need to access two different links here and here.

Here is the Three-Month Forecast which was issued on September 19, 2019

Here is the Monthly Drought Outlook which was updated on August 31, 2019

Floods remain a concern but only in a limited area.

Let’s see if this animation works. It shows the pattern for August.

How has the reduction in in flooding impact Fieldwork Days?

Active Major Fires

Current Wildfire Risk

Click here to update. Red is high risk, blue is low risk. This graphic updates daily but you have to click on the link provided to get the updates More information can be found here.

This explains the model a bit.

Looking out another month.

Crop Progress

Recently, we looked at the individual crop progress reports graphically from this source. Also recently we reviewed this Executive Summary Report which provides projections of the ultimate harvest. It is important to make the distinction between crop progress which we report in this section of our article weekly and forecasts of what the result for the crop will ultimately be and we review that information as the NASS forecasts are released. One a month they issue a briefing document on the situation.

Now, we will look at the season to date information summary. So that is a crop progress report, not a forecast.

The following table summarizes the situation. It has changed just a bit since last week for cotton.

This provides some additional information: There are many factors that have led to the current situation but one is the amount of sunshine other causes of temperature and it has been inadequate.

Side by Side

International

A map helps and is not always available and fortunately, it was available this week.

International Reports

Severe Drought Reduces 2019 Corn Production in Zambia and Zimbabwe

Zambia and Zimbabwe corn production for MY 2019/20 is estimated at 2.0 and 0.77 million metric tons (mmt), respectively, down 33 and 41 percent from the 5-year average due to a severe drought in both countries. The 2019 drought did not reduce production as much as the 1992 drought, when production reductions for Zambia and Zimbabwe were 66 and 80 percent below the 5-year average. In addition, corn production reductions during the 1992 and 2019 droughts were most severe in the Southern province of Zambia where outputs were 93 and 84 percent, below the 1992 and 2019 5-year averages (Figures 1-2).The 2018/19 growing season drought was the driest rainy season (October through April) since 1981 and the 2019 mid-season drought from February 16 through March 15 was also the driest mid-season period since 1981 (Figures 3-4). The mid-season drought in southern Zambia significantly reduced corn production because it occurred during the critical pollination stage and ears of corn were not produced due to ack of soil moisture and high temperatures (Figure 5). Soil moisture reserves reached the permanent wilting point in early March and beneficial rains after March 15 could not possibly revive the crop or dried-out corn stalks found throughout the Southern Province of Zambia in mid-March (Figure 5). The 2019 mid-season drought in southern Zambia caused many highly productive farmers and their families to stand in food aid lines for the first time in their lives because the April harvest yielded nothing. These same farmers also do not have cash to purchase seed and fertilizer inputs for the upcoming 2019/20 crop season because earnings from last year’s harvest were spent on seed and fertilizer inputs for the 2018/19 season. The typical growing season for Zambia and Zimbabwe beginsin October through December and ends April through June (Figure 6).Current area and production estimates for grains and other agricultural commodities are available from

Severe Drought Curtails Hydropower Production in Zambia and Zimbabwe

The 2019 drought in southern Zambia was the driest rainy season (October through April) since 1981 and it covered most of the Lake Kariba’s drainage basin in the southern half of Zambia and northeastern Zimbabwe (Figure 1). The well below-average rainfall during the 2018/19 rainy season did not recharge the Kariba reservoir and current water levels (August 30, 2019) are the lowest since July 1996. Similar low water levels in July occurred during 1993-97, 2005-07, and 2015-16 (Figures 2-3).

The low water levels in Kariba reservoir (478.2 meters) are approaching the minimum operation level of 475.5 meters when hydropower must be suspended (Figure 4). Recent press reports state that the low water levels have introduced power rationing schedules with rotational power outages ranging from 18 hours-per-day in Zimbabwe and 4 hours-per-day in parts of Zambia. Power authorities also have warned that hydropower generation could be suspended by the end of September if stringent power rationing schedules are not followed. Unfortunately, power rationing will probably continue through 2020 because the maximum annual recharge rate during the past 25 years was only 3.6 meters per year during the 2017/18 rainy season (Figure 4).

The 2019 drought caused the greatest annual water level drop of 7.6 meters during the July-to-July period because the 2018/19 rains did not recharge the reservoir and current water levels are not expected to rise until the onset of seasonal rains in November 2019. In general, Lake Kariba water levels decline during the dry season from June through October and the reservoir is recharged during the rainy season from October through April (Figure 4). The Kariba reservoir was created and designed to operate between levels 475.5 and 488.5 meters above mean sea level (amsl) for a total operational range of 13 meters. The lowest water level reached 475.91 meters amsl in December 1992 and the water level projection by the end of December 2019 is 476.8 meters amsl, if a decline of 0.4 meters per month continues for the remainder of the year (Figure 5).

Lake Kariba is the world’s largest man-made lake and reservoir by volume, and it was filled from 1958 through 1963 after construction of the Kariba Dam on the Zambezi river was completed in 1958. The Zambezi river forms the entire Zambia and Zimbabwe border and the Kariba Dam and reservoir are located approximately halfway between Zambezi river’s source and mouth. The Kariba Dam is a double curvature concrete arch dam and it is outfitted with two power stations with a total hydropower capacity of 2130 megawatts (MW). The North Bank Power Station is operated by ZESCO in Zambia and has an installed capacity of 1,080 MW, while the South Bank Power Station is operated by ZPC in Zimbabwe and it has an installed capacity of 1,050 MW.

Major Sources of Information

In the box are shown the major resources we use. We will not be using them all each week but the reader is welcome to refer to these resources.

Background Information

The 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