Wednesday, November 22, 2017

National Drought Mitigation Center

Drought and Climate for October 2017: Drought worsens in southern United States

Access the latest monthly drought outlook from NOAA's Climate Prediction Center.
 
The two maps above are from the High Plains Regional Climate Center.
 
Find these and other products related to the U.S. Drought Monitor on the USDM website.

By Deborah Bathke, NDMC Climatologist

Drought

October generally brought improvements in drought conditions to the Pacific Northwest, central Plains, Midwest, and Northeast while parts of the Southwest, South, and Southeast saw a degradation in conditions.  By month’s end, the percentage of the country experiencing drought (D1-D4) increased slightly, from 4.98 percent of the contiguous United States to 5.28 percent. Moderate drought (D1) decreased slightly from 14.36 to 11.95 percent, severe drought (D2) decreased from 4.73 to 2.67, extreme drought (D3) decreased from 1.39 to 0.88 percent, and exceptional drought (D4) was eliminated.  Drought decreased slightly in Hawaii (from 65.35 to 46.98 percent) while Alaska and Puerto Rico remained drought free.  The number of people being affected by drought dropped from nearly 31 million to about 26.7 million.

Drought Outlook

As the Northwest enters its climatologically wet time of year, Washington, northern Idaho, and northwest Montana can expect to see above-normal precipitation and a removal of drought conditions.  November in the High Plains is relatively dry, so drought conditions in eastern Montana and the Dakotas are likely to persist. Parts of Texas and the southwestern United States can expect to see the persistence or development of drought in response to forecasts of warmer and drier than normal conditions.  In the eastern half of the country, above-normal precipitation during November will likely to lead to the removal of drought conditions across the Midwest, Mid-Atlantic, and Northeast while parts of the lower Mississippi Valley and Southeast are expected to see persistence or the development of drought.  Drought is expected to persist through November in Hawaii, and Alaska and Puerto Rico are expected to remain drought free.

Temperatures

Record warmth spanned New England in October where temperatures were as high as 10 degrees above normal.  Above-normal temperatures were also observed in the Midwest, Southeast, Lower Mississippi Valley, and Southwest.  Below-normal temperatures were observed in the Northwest and northern Rockies, with departures generally ranging from 1 to 4 degrees below normal. According to the National Centers for Environmental Information, the year-to-date U.S. average temperature was the third warmest since 1895.

Precipitation

Above-normal precipitation fell in the central Plains, Midwest, Northeast, Appalachians, and central Gulf Coast during October. Below-normal precipitation was observed in the Southwest and parts of the northern and southern Plains. According to the National Centers for Environmental Information, the year-to-date U.S. precipitation total was the second wettest since 1895.  Michigan set a record for the wettest October and 7 other states (Maine, New Hampshire, Massachusetts, Connecticut, Kentucky, Iowa, and Wisconsin) had statewide totals that fell in the top 10 wettest.  Utah and Arizona each had statewide totals that were ranked as the fifth driest.

Regional Overviews

Northeast

October was warmer than normal for the entire Northeast, with most areas experiencing average temperatures 4 to 10 degrees above normal. Nearly the entire region saw above-average precipitation with the wettest areas receiving 200 percent of their normal monthly precipitation totals, most of which fell during the latter half of the month.  The abundant rainfall recharged soil moisture, aided streamflow recovery, and eliminated areas of moderate drought in the region.

Southeast

October temperatures in the Southeast ranged from slightly below normal in the southern Florida Peninsula to 6 degrees above normal in parts of Virginia and Maryland.  Precipitation ranging from 150 to 300 percent of normal fell across a broad region stretching from the southern Appalachians to the Gulf Coast as well as parts of the Florida Panhandle.  In contrast, central North Carolina, central South Carolina, southeastern Georgia, and northern and central Florida received less 50 percent of their normal monthly precipitation.  The lack of precipitation in these areas resulted in an expansion of abnormal dryness as well as the introduction of moderate drought in south central Virginia, central North Carolina, and north central South Carolina. Regionwide, moderate drought accounted for 2.29 percent of the area, with no depiction of higher severity classifications.

Movers & Shakers for October 2017
State

Percent area October 3, 2017

Percent area October 31, 2017 Status Percentage point change
Biggest increases in drought
Arizona 10.69 41.27 Moderate 30.58
Arkansas 29.13 62.17 Moderate 33.04
Louisiana 2.79 9.47 Moderate 6.68
Mississippi 0 18.93 Moderate 18.93
Missouri 22.17 34.54 Moderate 12.37
North Carolina 0 8.42 Moderate 8.42
Utah 6.93 12.48 Moderate 5.55
Virginia 0 3.75 Moderate 3.75
Biggest improvements in drought
Hawaii 65.35 46.98 Moderate 18.37
Idaho 16.28 1.30 Moderate 14.98
Illinois 13.27 3.50 Moderate 9.77
Indiana 8.46 1.88 Moderate 6.58
Iowa 34.72 5.96 Moderate 28.76
8.70 0 Severe 8.70
3.20 0 Extreme 3.20
Kansas 10.08 0.64 Moderate 9.44
Maine 24.62 0 Moderate 24.62
Michigan 5.40 0 Moderate 5.40
Montana 76.49 73.37 Moderate 3.12
65.77 41.50 Severe 24.27
23.40 14.90 Extreme 8.50
10.19 0 Exceptional 10.19
North Dakota 59.79 36.83 Moderate 22.96
18.90 3.15 Severe 15.75
Ohio 14.22 10.97 Moderate 3.25
Oklahoma 14.10 2.75 Moderate 11.35
Oregon 28.75 0 Moderate 28.75
South Dakota 57.96 49.06 Moderate 8.90
32.30 18.64 Severe 13.66
Washington 63.66 14.80 Moderate 48.46
Wisconsin 4.94 0 Moderate 4.94

South

Temperatures in the South ranged from 2 degrees below normal in South Texas to 3 to 4 degrees above normal in locations in eastern Mississippi and eastern Tennessee.  Two broad areas of above-normal precipitation occurred in the South during October.  In the western half of the region, portions of the Texas Panhandle and eastern Oklahoma received in excess of 150 percent of normal precipitation, supporting the removal of the moderate drought conditions in these areas.  In the eastern half, locally heavy rains brought more than 200 percent of normal precipitation to the Gulf Coast, eastern Alabama, and Tennessee. These rains missed the driest part of the region, resulting in an expansion of moderate drought in northern Louisiana, Arkansas, and eastern Mississippi, where monthly rainfall totals ranged from 5 to 70 percent of normal.  Severe drought was also introduced in South Texas, which has a precipitation deficit of more than 8 inches over the last 90 days.  As a whole, moderate drought increased from 6.19 to 10.50 percent and severe drought increased from 0 to 0.6 percent.

Midwest

The Midwest was predominantly warmer than normal during October.  Temperatures ranged from 1 to 2 degrees above normal in the western part of the region to more than 6 degrees above normal in eastern Wisconsin, northern Michigan, and northeastern Ohio.  Precipitation was more variable.  The driest areas, in northern Minnesota and southern Missouri, received less than 25 percent of their normal monthly precipitation.  The continued dryness, combined with rainfall deficits over the last 30 to 90 days, drove the expansion of moderate drought across southeast Missouri.  At month’s end, moderate drought had decreased from 11.91 to 7.46 percent of the region and severe and exceptional drought had been eliminated.

High Plains

During October, temperatures across eastern parts of the Dakotas, Nebraska, and Kansas as well as in southern Colorado were near to above normal, with departures generally ranging from 0 to 4 degrees above normal.  Meanwhile, the western parts of the Dakotas, Nebraska, and Kansas, northern Colorado, and Wyoming saw near- to below-normal temperatures, with departures generally ranging from 0 to 4 degrees below normal.  Monthly rainfall totals in north central and eastern Kansas, eastern Nebraska, and southeastern South Dakota ranged from 150 to 300 percent of normal.  The excess rainfall helped alleviate areas of severe and moderate drought that had been plaguing these areas since summer.  Improvements to drought conditions were also seen in the western Dakotas and western Colorado as near-normal rainfall amounts combined with cooler temperatures helped to ease impacts.  Compared to the beginning of the month, moderate drought in the High Plains was reduced from 20.46 to 13.70 percent, severe drought from 7.73 to 3.26 percent, and extreme drought from 1.10 to 0.90 percent.

West

Temperatures in the West were cooler than normal in the northern part of the region and warmer than normal in the south, with departures ranging from 5 degrees below normal to 6 degrees above normal.  The Pacific Northwest, north central Montana, and eastern New Mexico recorded excess monthly rainfall totals ranging from 110 to more than 200 percent of normal.  The October rains have helped to chip away at the longer-term deficits and improved soil moisture conditions and vegetation in these areas.  Accordingly, much of the Northwest saw at least a one-category improvement in the drought depiction.  The hot weather in the West’s southern tier combined with mounting precipitation deficits led to the deterioration in drought conditions in southeast Utah, western New Mexico, and southern Arizona.  Overall, the West only saw small changes in the percent area being affected by drought.  Moderate drought decreased from 19.71 to 16.48, severe drought decreased from 8.24 to 5.34, extreme drought decreased from 2.90 to 1.85, and exceptional drought was eliminated.

Alaska, Hawaii, and Puerto Rico

Alaska and Puerto Rico continued to remain drought free.  In Hawaii, windward rainfall helped ease drought conditions over part of the islands, resulting in a decrease in moderate drought from 65.35 to 46.98, severe drought from 14.78 to 11.79, and extreme drought from 2.35 to 2.14 percent.


October 2017 impact summary: Parts of South see dry landscapes, increased fire danger, water restrictions

The two charts above summarize information from the Drought Impact Reporter.

By Denise Gutzmer, NDMC Drought Impact Specialist

Autumn brought relief to many drought-stricken areas of the northern United States, while drought worsened in parts of the South.  During October, the NDMC added 147 impacts to the Drought Impact Reporter, largely documenting the way drought affected plants and wildlife.  Of the 147 impacts, 87 were from Community Collaborative Rain, Hail and Snow (CoCoRaHS) Network observers, noting changes in their landscapes as dryness intensified.

In Texas, dry conditions brought agricultural challenges and increasing fire danger as parts of the state dried out in October, resulting in 21 impacts.  CoCoRaHS observers in Illinois submitted 15 impacts for the state, reporting many brown lawns and other evidence of unusual autumn dryness.  Poor rainfall in Virginia led to water restrictions and drought advisories for some portions of the state, amounting to a dozen impacts. 

Texas

Texas experienced areas of abnormal dryness in October, which CoCoRaHS observers noted in their reports.  Descriptions of brown grass and dry pasture were common.  Counties in the northeast and the west central region had burn bans in effect because of the dryness and resulting fire danger.  In various counties, crop planting was delayed because of the dryness.

Illinois

CoCoRaHS observers in Illinois noted plenty of brown lawns, dying plants and trees dropping leaves in ways that indicated drought stress to the observers, such as leaves curling and turning brown on the trees or leaves falling early.  Dry streams and large cracks in the ground were other concerns.

Virginia

In early October, the dearth of rain in Virginia led the state Department of Environmental Quality to issue a drought watch advisory for the Northern Piedmont because the region received 83 percent of normal precipitation between Oct. 1, 2016, and Sept. 15, 2017.  The Middle James, Roanoke and Shenandoah regions were also in drought watch advisories as of Nov. 3. 

Concern about drought ramped up quickly in the Charlottesville area when the Rivanna Water and Sewer Authority declared a drought watch on Oct. 3 for the Charlottesville-Albemarle County area and a warning on Oct. 5 because the water level of the South Fork Rivanna Reservoir continued to fall.  By Oct. 9, the Albemarle County Service Authority Board of Directors declared a water emergency because of the drought.  Rainfall has since boosted the level of the South Fork Rivanna Reservoir, but mandatory water restrictions remained in effect. 

With no real rain for weeks, town of Orange enacts water restrictions, by Allison Brophy Champion, Culpeper Star-Exponent (Virginia), Oct. 5, 2017

Residents asked to limit outdoor watering, WCAV-TV Charlottesville Newsplex (Virginia), Oct. 3, 2017

Officials Place Charlottesville Area Under Drought Warning, by Taylor Gleason, WVIR-TV NBC29 (Charlottesville, Virginia), Oct. 5, 2017

ACSA Declares Water Emergency Due to Drought, by Spencer Burke, WVIR-TV NBC29 (Charlottesville, Virginia), Oct. 9, 2017

RWSA: Water levels improving since drought warning issued, by Allison Wrabel, The Charlottesville Daily Progress (Virginia), Oct. 24, 2017

North Carolina

North Carolina’s CoCoRaHS observers sent in 8 of the 9 impacts for the state in October, making note of leaves falling early or being otherwise affected by the dry fall and plants and trees wilting or appearing stressed.  The North Carolina Drought Management Advisory Council also observed the unusual dryness and issued a moderate drought advisory for a dozen counties in the northern Piedmont.  The area typically receives 35 to 40 inches of rain by mid-October, but had only gotten 25 to 30 inches this year. 

It’s rained a lot, but there’s a moderate drought in Wake, surrounding counties, by Camila Molina, Raleigh News & Observer (North Carolina), Oct. 19, 2017

Northern Plains

Despite the droughty summer in the northern Plains that hammered the agriculture sector, a vintner from the Dickinson, North Dakota, area reported that 2017 was great for grapes, resulting in a bumper crop.  Chokecherries and apples thrived too in the hot, dry weather.

Pastures and livestock, on the other hand, suffered over the summer.  In southeast Montana, more than 40,000 cattle have been sold at auction in Miles City and Billings since July as ranchers try to cope with parched pastures and lack of grazing for cattle. Stockyards moved 6,000 more cattle than in 2016 and 11,000 more than in 2015.

Just as pastures were seared by the drought, pheasant habitat in eastern Montana was also severely affected, which lowered brood success.  The final results of the brood survey have not been published, but the brood count was down significantly.  In parts of South Dakota, the previous harsh winter and parched summer cut down the pheasant population to about one-third of the ten-year average.  There was concern that poor pheasant counts would draw fewer nonresidents for the hunt, depriving South Dakota of millions in economic activity.

Grapes, fruit have great year in N.D., by Jessica Holdman, The Bismarck Tribune (North Dakota), Oct. 14, 2017

Montana drought drives cattle to market early, by Tom Lutey, Billings Gazette (Montana), Oct. 14, 2017

Pheasant numbers suffer from Montana drought, by Tom Carpenter, Pheasants Forever, Ravalli Republic (Montana), Oct. 3, 2017

On brink of pheasant season, South Dakota bracing for drastically reduced bag, by Tony Kennedy, Minneapolis-St. Paul Star Tribune, Oct. 19, 2017

 

For more drought information, please visit the Drought Impact Reporter.

 

 

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