National Weather Service Text Product Display

Drought Information Statement
Issued by NWS Austin/San Antonio, TX
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Drought Information Statement
National Weather Service Austin/San Antonio TX
1005 AM CDT Thu May 6 2021

...SIGNIFICANT RAINFALL ACCUMULATIONS OVER THE LAST TWO WEEKS
LEAD TO DROUGHT IMPROVEMENTS...

SYNOPSIS...

Multiple rounds of showers and thunderstorms, some containing heavy
rainfall and others producing significant severe weather, have
impacted the region through late April and the first few days of
May. Initially, a band of 1-3" fell along and east of I-35 from
eastern Bexar to Lee counties on the 23rd with scattered amounts of
less than an inch. Then, strong to severe storms again brought 1-3"
from San Antonio westward with another thin stripe of 1-2" stretching
through Bandera, eastern Kerr, and parts of Gillespie and Llano
counties.

Some lighter rainfall continued into the 29th, but heavy rain
returned on the 30th into the early morning of May 1st as a cut-
off low stalled over the region. Many locations along and east of
I-35 picked up 1-3", and a few spots saw as much as 5" of rain.
The next day, the axis of heavy rain shifted mainly along and west
of I-35, again with a widespread 1-3" through the Hill Country.
Lastly, a few severe storms on the evening of the 3rd dropped up
to an inch or so across central Bexar county and along a stripe
just west of hwy 281.

In total just over the past 10 days, the entire forecast area except
for Dimmit, southern Maverick, and much of Val Verde counties has
seen an inch and a half or greater of accumulation. A sizable
chunk, about 40% of the region has received 4+", with scattered
pockets greater than 6". Notably, a small portion of western Bexar
County has seen near 11" of rain in the last 10 days.

As a result of the substantial precipitation amounts, drought status
has begun to improve across much of the area. The May 6th issuance
of the Drought monitor, valid May 4th, now depicts a stripe of no
drought from Wilson and SE Bexar northeastward through Lee and
eastern Williamson Counties, and another across Edwards and western
Kerr and Real Counties. In all, 20% of the area is no longer
under any drought.

Abnormally Dry (D0) status covers portions of the Hill Country,
Coastal Plains, and Edwards Plateau. Due to remaining long-term
deficits, an area of Moderate Drought (D1) stretches from Llano
south and southwestward into Medina, NW Bexar, NW Zavala, and
NE Maverick as well as portions of Lavaca, DeWitt, and Gonzales
counties, and covers 29% of our south-central Texas coverage
area. Where the largest deficits still remain, D2 or severe
drought is depicted along the Rio Grande from Del Rio southward,
then extends east into western DeWitt, with an area of extreme
drought, D3, remaining in Dimmit and far southern Zavala and Frio
counties. Over the past week, the D3 area has decreased from 15%
of the area to just 4%.

HYDROLOGIC CONDITIONS...

USGS waterwatch data have flipped considerably, with much of the
region now showing normal to above normal streamflows across much of
the area over the last 14 days. The exception is across the far
southwestern basin, for the Nueces River which remains below the
24th percentile. Meanwhile, portions of Bexar County as well as the
Medina river basin south of Castroville show streamflows above the
90th percentile. These values should subside over the next several
days with no rain in the forecast over most areas through Sunday.

SUMMARY OF IMPACTS...

Water Restrictions: These may change before the next issuance of
this product as 10 day aquifer levels stabilize.

Austin - Conservation Stage
Del Rio - Stage 1
Fredericksburg - Stage 3
Kerrville - Year Round Conservation
New Braunfels - Stage 2
San Antonio - Stage 2
San Marcos - Stage 1
Uvalde - Stage 1

Other locations may have water conservation or restriction rules
so be sure to check for your location.

Edwards Aquifer information:

Current Level     2019 Level     May Average    Difference
   665.2 ft        663.3 ft        665.7 ft       -0.5 ft

Since the last update, heavy rain has brought aquifer levels up by
nearly 20 feet, only half a foot from historical May averages.

Reservoir Conditions as of May 5th, 2021...

Below is a list of reservoirs with the latest elevations and
normal pools.

              Conservation Pool    Latest Elevation    Difference
                    (FT)                 (FT)             (FT)

Lake Amistad        1117                1067.8            -49.2
Medina Lake         1064.2              1026.9            -37.3
Canyon Lake          909                 903.7             -5.3
Lake Buchanan       1020                1012.5             -7.5
Lake Travis          681                 659.9            -21.1

Soil Moisture Impacts.

As of May 4th 2021, the Climate Prediction Center (CPC) indicated
the percent of available soil moisture has recovered over much of
south-central Texas, however it does still depict anomalies in the
20th percentile or below along our Rio Grande Plains counties. It
depicts soil moistures largely in the 30th to 70th percentiles
across the east half of our area. NASAs Short-term Prediction and
Transition Center - Land Information System (SPoRT- LIS) 0-100cm
relative soil moisture product valid April 23rd is a higher-
resolution dataset but paints a very similar picture, with a few
blotches above the 70th percentile where rainfall has been heaviest
over the past two weeks.

Fire Danger Hazards.

Fire Danger - May 5th

We are nearing the tail end of the spring fire weather season across
south central Texas, and with all the rainfall recently fuels will
be saturated over much of the region until after the last spring
front. Fire danger will generally be low east and moderate west over
the next several days. That said, we`re not entirely out of the
woods especially along our western counties. The National
Interagency Fire Center Predictive Service Outlook has added the
Edwards Plateau along our northwest border to Above Normal status
into June.

Texas A&M Forest Service indicated Keetch-Byram Drought Index (KBDI)
values have dropped considerably due to all the rain recently. The
exception is west and southwest, especially across Dimmit County.
KBDI is an index used to determine forest fire potential, which is
based on a daily water balance considering precipitation and soil
moisture. The KBDI can range from 0 to 800, where a value of 0
represents no moisture depletion, and 800 would be representative of
absolutely dry conditions. A KBDI between 600 and 800 is often
associated with severe drought and increased wildfire potential.

County KBDI values as of May 5th, 2021:

0-200                     200-300    300-400   400-500  500-600
Bandera       Guadalupe   DeWitt     Atascosa  Frio     Val Verde
Bastrop       Hays        Kendall    Edwards   Maverick
Bexar         Kerr        Real       Kinney
Blanco        Lavaca      Uvalde     Zavala
Burnet        Lee
Caldwell      Llano
Comal         Medina            600-700
Fayette       Travis            Dimmit
Gillespie     Williamson
Gonzales      Wilson


Texas A&M Forest Service maps indicated that burn bans are in
effect for 30 counties across the region. As of May 5th, 2021:

Counties with burn bans currently in place:
Bandera      Karnes
Bexar        Maverick
Dimmit       Real
Edwards      Val Verde
Frio         Zavala

Counties without burn bans currently in place:
Atascosa      Gonzales     Burnet
Lavaca        Guadalupe
Bastrop       Kendall
Blanco        Kerr
Gonzales      Kinney
Burnet        Lee
Caldwell      Lavaca
Comal         Llano
DeWitt        Uvalde
Fayette       Wilson
Gillespie     Williamson


Agricultural Impacts.

The Texas Crop and Weather report from Texas A&M AgriLife issued
May 4th notes:

-Some areas lost crops due to hail and heavy winds.
-Rangeland and pastures were not affected by severe weather and
should benefit from the added moisture
-Corn was responding to recent rains
-Supplemental feeding of livestock continued
-Some producers were thinning herd numbers in anticipation of a dry
summer.

No impacts have been reported directly to NWS Austin/San Antonio. We
welcome input on impacts from any users of this product now and in
the future!

LOCAL DROUGHT OUTLOOK...

The forecast is mostly dry through Sunday May 9th, however rain
chances will increase into next week. The NWS Climate Prediction
Center shows the odds are tilted towards wetter than normal
conditions into the middle of the month at 33-40%, which is good
news if the areas that are still dry can pick up a little more rain,
but hopefully no additional flash flood impacts are realized for
locations that are still saturated. The latest drought outlook for
the remainder of May does not anticipate additional drought
expansion. And although the temperature outlook is warm through June
with a low (33-40%) chance of drier than normal conditions, I think
at this point it`s safe to say we`re not looking at impacts anywhere
near those of 2011 for our region even if some modest expansion is
able to occur later this year.

La Nina is coming to an end with equatorial eastern Pacific Sea
Surface Temperatures warming back into the neutral category for
this summer. At this time, while forecast skill for the fall into
the winter is low, El Nino is the least likely outcome with
somewhat better chances for ENSO neutral to remain in place or La
Nina to return. Hopefully we`ll have a better idea in a few
months.

Local Rainfall for the Year to Date (note the normals are
now for the 1991-2020 period as of this issuance).

                     2021      Normal    Departure    Percent of
                    to Date   to Date   from Normal     Normal

Austin Bergstrom     9.01"     10.73"      -1.72"         84%
Austin Mabry         9.52"     10.54"      -1.02"         90%
Del Rio              4.02"     4.26"       -0.24"         94%
San Antonio          11.15"    9.06"       +2.09"         123%

NEXT ISSUANCE DATE... This product will be updated around Thursday
June 3, 2021 or sooner if necessary in response to significant
changes in conditions.


.RELATED WEB SITES:

Additional information on current drought conditions may be found
at the following web addresses:
US Drought Monitor: https://droughtmonitor.unl.edu
US Drought Information System: https://www.drought.gov
NOAA Drought Page: https://www.cpc.ncep.noaa.gov/products/Drought
Austin/San Antonio NWS...http://www.weather.gov/EWX

Additional water and river information:
NWS: https://water.weather.gov
OWP: https://water.noaa.gov
US Geological Survey (USGS): https://water.usgs.gov
US Army Corps of Engineers (USACE): https://www.usace.army.mil

.ACKNOWLEDGMENTS:

The Drought Monitor is a multi-agency effort involving NOAA`s
National Weather Service and the National Climatic Data Center,
the USDA, State,and Regional Center Climatologists and the
National Drought Mitigation Center. Information for this
statement has been gathered from NWS FAA observation sites, State
Cooperative Extension Services, the USDA, USACE, and USGS.

.CONTACT INFORMATION:

If you have questions or comments about this Drought Information
Statement, please contact:

National Weather Service
2090 Airport Road
New Braunfels Texas 78130
830-629-0130 Press 2

$$
National Weather Service Weather Forecast Office
