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A summary of drought conditions based on the
Apalachicola-Chattahoochee-Flint River Basin
Drought Assessment Webinar on February 7, 2017
Auburn University Water Resources Center and the National Integrated Drought Information System (NIDIS)
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The ACF Basin relief in the form of precipitation stalled over the past few weeks, therefore, improvements in drought conditions also stalled. As in the previous webinar, Exceptional drought (D4) no longer persists in the region. Nonetheless, moderate drought (D1)-to-extreme drought (D3) conditions persist through the northern half of Alabama and across a good bit of Georgia according to the most current US Drought Monitor (as of 1/31/2017).
Please share the following highlights of the recent NIDIS ACF Drought Assessment Webinar with others who might be interested.
Our next briefing will be Tuesday, February 21, 2017, 1 pm ET.
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Current Drought Status
Exceptional drought (D4) no longer persists in the region. Nonetheless, moderate drought (D1)-to-extreme drought (D3) conditions persist through the northern half of Alabama and Georgia (as of 1/31/2017).
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Rainfall over the past 90 days
The ACF Basin has seen much-needed relief in the form of precipitation over the past 90 days in the basin, particularly in southern Alabama and Georgia.
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Official NOAA 3-Month Outlook
According to the most recent NOAA 3-month Precipitation Probability Outlook (1/19/2017), the southeastern U.S. continues to have a higher probability of below-normal rainfall (areas in shades of brown).
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U.S. Drought Monitor
According to the most recent U.S Monthly Drought Outlook, areas of drought in the ACF Basin and in adjoining states continue to recede, and the areas that remain in drought conditions are likely to persist but improve or see possible drought removal; although the majority of Florida is forecast to see drought development.
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Realtime Streamflow
Realtime streamflows have suffered over the past few weeks because of lack of significant rainfall, with several streams dropping to below-normal to low (red and brown dots), particularly in central to north AL and GA, while south AL and GA streams are faring better, mostly in the normal range
(
http://waterwatch.usgs.gov
).
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Below-Normal 7-day Average
Streamflows
Previous Brief:
Current Brief:
According to the current Below-Normal 7-day Average S
treamflow Map,
streams throughout most of Alabama and northern Georgia have reverted to moderate-to-extreme hydrologic drought based on 7-day average flows
(see http://waterwatch.usgs.gov).
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Flint River at Bainbridge Streamflow
Streamflow for the Flint River at Bainbridge has risen from record seasonal low flow to above-normal flow; with flows at Griffin, Carsonville, and Albany showing similar trends (see
http://waterwatch.usgs.gov
).
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Groundwater Conditions
Previous Brief: Current Brief:
Groundwater conditions have remained about the same over the past few weeks, ranging widely from low (red) to above-normal (light blue) in the ACF Basin (
http://waterwatch.usgs.gov
).
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3-Month Mean Daily Streamflow Forecast
Streamflows throughout the ACF Basin are forecasted at a slightly higher chance of being below-normal based on 3-month mean daily streamflow forecasts from the Southeast River Forecast Center; with flows up in the Lake Lanier Basin forecast at a greater-than-50 percent probability of being below normal.
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ACF Basin Composite Conservation and Flood Storage
Although the Flood Storage is in Zone 2, the ACF System Conservation Storage has dropped into Zone 3 and is forecasted to stay in Zone 3.
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Drought Assessment Webinar Summary
*We've seen a d
ramatic improvement in the U.S. Drought Monitor the last two
months.
*None-the-less, there's been l
ess than an inch of rainfall over any part of the basin in the last two weeks, and less than half inch over the headwaters of the ACF Basin.
*There's been a
bove-
normal rainfall over the last 90 days for much of the middle and lower
ACF Basin.
*
In the heart of the winter recharge season, February is the wettest month of the year for much of the upper and middle ACF B
asin.
*We are c
urrently on pace for a top 10 warmest
winter.
*
La Nina conditions have dissipated in the
Pacific.
*
Real-time
streamflows
in the ACF Basin range from low
to normal.
*
28-day average streamflows into Lake Lanier, as indicated by Chattahoochee River at Cornelia and Chestatee River at Dahlonega, are currently in the much-below-normal range.
*
28-day average streamflows for the Chattahoochee River below Lake Lanier are in the normal to below-normal range.
*
28-day average streamflows for the Flint River are currently in the normal to above-normal range.
*
Groundwater levels range from low to above-normal across the ACF Basin, with a majority of groundwater wells in the normal range.
*The Southeast River Forecast Center's
1 month streamflow forecast favors near
-normal flows for the ACF Basin (to almost back into below-normal) except Lanier Inflows which are well below normal. The 3 month forecast also favors near-normal flows to potentially slightly below-normal flows, except Lanier inflows which are forecast to be below-normal.
Note, streamflow forecast p
ie charts do not directly include any adjustments to the ESP forecast based on ENSO, CPC or other factors, but are based on soil conditions relative to normal in concert with historical precipitation.
*
Buford still remains below winter levels, while
West Point and Walter F. George are above winter levels
.
*
Although the Flood Storage is in Zone 2, the ACF System Conservation Storage has dropped into Zone 3 and is forecasted to stay in Zone 3.
*The Corps is continuing to meet downstream minimum flow requirements.
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Acknowledgments and Resources:
- David Zierden, FSU
- Paul Ankcorn, USGS
- Todd Hamill, SERFC
- Tom Littlepage, AL OWR
- Cynthia Donald, US ACE
Summary prepared by Eric Reutebuch, Auburn University
General drought information
General climate and El Niño information
Streamflow monitoring & forecasting
Groundwater monitoring
Additional information can be found at the Southeast River Forecast Center's Water Resources Outlook:
Experimental Long-Range River Flood Risk
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