DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1220 PM CDT FRI AUG 1 2008
...SLIGHT IMPROVEMENTS TO DROUGHT CONDITIONS ACROSS SOUTH CENTRAL TEXAS...
SYNOPSIS...
UPPER LEVEL HIGH PRESSURE HAS REMAINED IN PLACE ACROSS THE REGION
FOR MOST OF THE SUMMER. THE UPPER LEVEL HIGH PRODUCES SINKING AIR
WHICH DOES NOT ALLOW FOR MUCH CLOUD DEVELOPMENT AND LITTLE TO NO
RAINFALL. MANY TIMES IN THE SUMMER TROPICAL SYSTEMS WILL MOVE
AROUND THE SUBTROPICAL HIGH AND CAN MOVE INLAND ALONG THE TEXAS
COAST. HURRICANE DOLLY DEVELOPED OVER THE WESTERN CARIBBEAN AND
MOVED INLAND NORTH OF BROWNSVILLE TEXAS. THE SYSTEM THEN MOVED
NORTHWEST TO LAREDO TEXAS AND THEN INTO MEXICO AND THE BIG BEND
REGION OF WEST TEXAS. DOLLY DID PRODUCE SOME RAINFALL ACROSS SOUTH
CENTRAL TEXAS. THIS RAINFALL WAS WELCOMED FOR THE SHORT TERM...BUT
NOT WIDESPREAD ENOUGH TO ALLEVIATE THE LONG TERM DRY CONDITIONS.
NEARLY ALL LOCATIONS ACROSS THE WEST AND SOUTHWEST PORTION
OF SOUTH CENTRAL TEXAS HAVE RECEIVED LESS THAN 5 INCHES OF
RAINFALL SINCE THE BEGINNING OF 2008. RAINFALL DEFICITS CONTINUE
TO CLIMB...WITH MUCH OF THE REGION REACHING 6 OR MORE INCHES BELOW
NORMAL YEAR TO DATE RAINFALL. SOME AREAS ACROSS THE REGION NOW
HAVE RAINFALL SHORTAGES AS HIGH AS 12 INCHES FOR 2008 SO FAR.
THE US DROUGHT MONITOR (USDM) VALID JULY 29TH SHOWED AN AREA OF
(D4)...EXCEPTIONAL DROUGHT SEVERITY CENTERED ACROSS FAYETTE...
BASTROP...LEE...MOST OF LAVACA...THE EASTERN THIRD OF GONZALES
COUNTY...A SMALL PORTION OF NORTHEAST GUADALUPE COUNTY...THE
EASTERN HALF OF HAYS COUNTY...THE NORTHERN TWO THIRDS OF COMAL
COUNTY...THE EXTREME NORTHERN PORTION OF BEXAR COUNTY...THE
THE SOUTHERN HALF OF KENDALL COUNTY...MOST OF BANDERA COUNTY
AND THE SOUTHEAST PARTS OF TRAVIS COUNTY. A SMALL AREA OF (D2)
SEVERE DROUGHT WAS PRESENT ACROSS NORTHWEST VAL VERDE
COUNTY...NORTHERN GILLESPIE COUNTY...THE EXTREME NORTHWEST PORTION
OF BLANCO COUNTY...THE WESTERN HALF OF WILLIAMSON COUNTY...LLANO
AND BURNET COUNTIES. ANOTHER SMALL AREA OF (D2) SEVERE DROUGHT WAS
LOCATED ACROSS NORTHERN HALF OF MAVERICK COUNTY...THE EASTERN HALF
OF DIMMIT COUNTY AND THE WESTERN HALF OF ZAVALA COUNTY. SOUTHERN
MAVERICK COUNTY AND WESTERN DIMMIT COUNTY ARE IN (D1)...MODERATE
DROUGHT CONDITIONS. THE REMAINDER OF THE FORECAST AREA REMAINS IN
(D3)...EXTREME DROUGHT SEVERITY.
SUMMARY OF IMPACTS...
FIRE DANGER IMPACTS...
FIRE DANGER IS LOW TO MODERATE ACROSS THE REGION AFTER THE
RECENT RAINFALL. MOST GRASS AND FINE FUELS THAT WERE BROWN HAVE
TURNED GREEN...BUT SIGNIFICANT RAINS ARE NEEDED TO REDUCE THE
WILDFIRE THREAT. MANY COUNTIES CONTINUE TO SUPPORT COUNTY WIDE
BURN BANS. AS OF AUGUST 1ST BURN BANS WERE IN EFFECT FOR 29
COUNTIES IN SOUTH CENTRAL TEXAS. THE COUNTIES WITH ESTABLISHED
OUTDOOR BURN BANS INCLUDE...ATASCOSA...BASTROP...BEXAR...
BLANCO...BURNET...CALDWELL...COMAL...DIMMIT...EDWARDS...
FAYETTE...FRIO...GILLESPIE...GONZALES...GUADALUPE...HAYS...
KARNES...KENDALL...KERR...LAVACA...LEE...LLANO...MAVERICK...
MEDINA...REAL...TRAVIS...VAL VERDE...WILLIAMSON...WILSON AND
ZAVALA COUNTIES. RESIDENTS IN COUNTIES NOT LISTED SHOULD CONTACT
THEIR LOCAL COUNTY JUDGE'S OFFICE BEFORE DECIDING TO BURN...IN
ORDER TO ENSURE THAT THE COUNTY HAS NOT ENACTED A BURN BAN.
THE JULY 31ST KEETCH-BYRAM DROUGHT INDEX (KBDI) SHOWS THAT MOST OF
SOUTH CENTRAL TEXAS IS IN THE 600 TO 800 RANGE. BASTROP...
CALDWELL...LEE AND KINNEY COUNTIES WERE REPORTING A KBDI INDEX OF
700 TO 800. ATASCOSA COUNTY REPORTED A KBDI INDEX OF 400 TO 500.
THE TEXAS FOREST SERVICE USES THE KBDI AS A MEANS FOR RELATING
CURRENT AND RECENT WEATHER CONDITIONS TO POTENTIAL OR EXPECTED
FIRE BEHAVIOR. THE KBDI IS A NUMERICAL INDEX CALCULATED DAILY FOR
EACH COUNTY. EACH NUMBER IS AN ESTIMATE OF THE AMOUNT OF
PRECIPITATION...IN HUNDREDTHS OF AN INCH...NEEDED TO BRING THE
SOIL BACK TO SATURATION. THE INDEX RANGES FROM ZERO TO 800...WITH
ZERO REPRESENTING A SATURATED SOIL AND 800 A COMPLETELY DRY SOIL.
REMEMBER...THAT FIRE DANGER CAN CHANGE QUICKLY FROM ONE DAY TO
ANOTHER AS WINDS AND RELATIVE HUMIDITY VARY.
AGRICULTURAL IMPACTS...
THE JULY 30TH TEXAS CROP AND WEATHER REPORT ISSUED BY TEXAS
A AND M AGRICULTURAL PROGRAM...THE FOLLOWING AGRICULTURAL IMPACTS
WERE NOTED. MUCH OF THE REGION REMAINED DRY...BUT SCATTERED
THUNDERSTORMS DID PRODUCED TWO TO FOUR INCHES OF RAIN ACROSS THE
EAST AND LESS TAN ONE INCH OVER MOST OF THE WEST. THE YEAR TO
DATE CUMULATIVE RAINFALL REMAINED ABOUT 70 PERCENT BELOW THE LONG
TERM AVERAGE. COTTON AND PEANUTS MADE GOOD PROGRESS UNDER HEAVY
IRRIGATION. THE CORN AND SORGHUM HARVEST WERE UNDERWAY. THE
WATERMELON AND CANTALOUPE HARVEST WAS WINDING DOWN.
CLIMATE SUMMARY...
SINCE JANUARY 1, 2008 RAINFALL ACROSS MUCH OF THE REGION HAS SEEN
4 TO 8 INCHES. HIGHER AVERAGE AMOUNTS OF 9 TO 12 INCHES HAVE
FALLEN ACROSS THE EAST AND SOUTHEAST PORTIONS OF SOUTH CENTRAL
TEXAS. THE WESTERN THIRD OF THE REGION ALONG THE RIO GRANDE
PLAINS HAS RECEIVED LESS THAN 5 INCHES OF RAIN FOR THE YEAR SO
FAR.
PRECIPITATION FROM JANUARY 1, 2008 TO JULY 31, 2008 AND DEPARTURE
FROM NORMAL:
2008 RAINFALL NORMAL TO DATE DEPARTURE
AUSTIN MABRY 10.53 19.34 -8.81
AUSTIN BERGSTROM 11.79 19.79 -8.00
SAN ANTONIO 7.80 18.95 -11.15
DEL RIO 5.04 10.87 -5.83
SO FAR 2008 HAS BEEN VERY WARM AND DRY AND THIS TREND CONTINUED
INTO JULY. JULY IS NORMALLY ONE OF THE DRIEST AND WARMEST
MONTHS...BUT THE FIRST 10 DAYS SAW ABOVE NORMAL RAINFALL AND
SLIGHTLY COOLER THAN NORMAL TEMPERATURES AND THEN AGAIN DURING
THE PERIOD OF JULY 23RD-25TH DUE TO HURRICANE DOLLY.
SO FAR SAN ANTONIO HAS RECEIVED ONLY 41 PERCENT OF THE NORMAL
YEARLY RAINFALL SINCE JANUARY 1. THE PERIOD FROM JANUARY 1, 2008
TO JULY 31, 2008 THE 7.80 INCHES OF RAINFALL MAKES THIS THE 9TH
DRIEST JANUARY THROUGH JULY PERIOD ON RECORD.
DEL RIO HAS SEEN SOME MUCH NEED RAINFALL AND THIS HAS PUSHED THEIR
PERCENTAGE OF NORMAL TO 46 PERCENT SINCE JANUARY 1. THE RAINFALL TOTAL
FROM JANUARY 1, 2008 TO JULY 31, 2008 OF 5.04 INCHES MAKES THIS PERIOD
THE 12TH DRIEST ON RECORD.
AUSTIN MABRY HAS RECORDED 54 PERCENT OF THEIR NORMAL YEARLY
RAINFALL SINCE JANUARY 1ST. FOR THE PERIOD JANUARY 1, 2008 THROUGH
JULY 31, 2008 THE 10.53 INCHES OF RAINFALL MAKES THIS PERIOD THE
11TH DRIEST ON RECORD.
AUSTIN BERGSTROM HAS RECEIVED 60 PERCENT OF THEIR NORMAL YEARLY
RAINFALL TO DATE. FOR THE PERIOD JANUARY 1, 2008 TO JULY 31, 2008
THE 11.79 INCHES OF RAINFALL MAKES THIS THE 9TH DRIEST ON RECORD.
PRECIPITATION/TEMPERATURE OUTLOOK...
SIGNIFICANT RAINFALL IS NOT EXPECTED FOR THE NEXT SEVERAL DAYS.
ISOLATED TO WIDELY SCATTERED AFTERNOON SHOWERS OR THUNDERSTORMS
ARE POSSIBLE FOR THE NEXT FEW DAYS AND AGAIN DURING THE WEEK OF
AUGUST 4TH THROUGH THE 8TH. TEMPERATURES ARE EXPECTED TO REMAIN
AT OR ABOVE NORMAL LEVELS FOR AUGUST.
THE LATEST CLIMATE PREDICTION CENTER (CPC) OUTLOOKS FOR THE NEXT
6 TO 10 DAYS ARE CALLING FOR EQUAL CHANCES FOR ABOVE...NORMAL OR
BELOW TEMPERATURES. THE OUTLOOK FOR RAINFALL IS CALLING FOR
GREATER THAN NORMAL CHANCES FOR BELOW NORMAL PRECIPITATION.
THE OUTLOOK FOR SEPTEMBER THROUGH NOVEMBER IS CALLING FOR EQUAL
CHANCES OF ABOVE...NORMAL OR BELOW NORMAL PRECIPITATION AND
GREATER CHANCES FOR ABOVE NORMAL TEMPERATURES.
HYDROLOGIC SUMMARY AND OUTLOOK...
THE MAIN IMPACTS OF DROUGHT HAVE BEEN TO AGRICULTURE...BUT THE
HYDROLOGIC IMPACTS ARE BEING FELT AS WATER USAGE HAS INCREASED AND
RESERVOIRS...LAKES AND AQUIFERS CONTINUE FALLING AT A STEADY PACE.
MOST RIVERS...STREAMS AND CREEKS ARE NEAR NORMAL LEVELS FOR THIS
TIME OF YEAR. THE 7 DAY STREAM FLOW AVERAGE IS IN THE 25 TO 75
PERCENT (NORMAL) RANGE FOR THE MAJORITY OF THE REGION WITH AN AREA
OF 10 TO 24 PERCENT (BELOW NORMAL) NOTED OVER THE LOWER COLORADO
RIVER BASIN AND AN AREA OF 76 TO 90 PERCENT (ABOVE NORMAL) ON THE
SAN ANTONIO RIVER BASIN.
RESERVOIR CONDITIONS AS OF AUGUST 1...
ALL AREA LAKES...RIVERS AND RESERVOIRS ARE NOW SEVERAL FEET BELOW
NORMAL POOL ELEVATIONS AND CONTINUE TO FALL. BELOW IS A LIST
OF RESERVOIRS WITH THE LATEST ELEVATIONS AND NORMAL POOLS.
NORMAL POOL (FT) LATEST ELEVATIONS (FT)
MEDINA LAKE 1064.2 1051.96
CANYON LAKE 909 903.85
LAKE TRAVIS 681 664.04
LAKE BUCHANAN 1020 1014.03
LAKE GEORGETOWN 791 777.28
LAKE AMISTAD 1117 1099.03
RESTRICTIONS...
MANY LOCATIONS HAVE IMPLEMENTED WATER RESTRICTIONS DUE TO LACK
OF RAINFALL AND DECREASING SUPPLIES. ALL LOCATIONS CONTINUE TO
STRONGLY PROMOTE YEAR ROUND WATER CONSERVATION.
NEXT ISSUANCE DATE...
THIS STATEMENT WILL BE UPDATED SEPTEMBER 5TH OR SOONER AS NECESSARY
IN RESPONSE TO SIGNIFICANT CHANGES IN AREA CONDITIONS.
RELATED WEB SITES...
FOR FURTHER INFORMATION ON THE DROUGHT IMPACTING SOUTH CENTRAL
TEXAS...PLEASE VISIT THE FOLLOWING WEB ADDRESSES.
AUSTIN/SAN ANTONIO NATIONAL WEATHER SERVICE:
http://www.srh.weather.gov/ewx/
NOAA DROUGHT INFORMATION CENTER:
http://www.drought.noaa.gov/
CLIMATE PREDICTION CENTER:
http://www.cpc.noaa.gov/
U.S. DROUGHT MONITOR:
http://www.drought.unl.edu/dm/monitor.html
OFFICE OF THE TEXAS STATE CLIMATOLOGIST:
http://www.met.tamu.edu/osc/
UNITED STATES GEOLOGIC SURVEY (USGS):
http://water.usgs.gov/
UNITED STATES ARMY CORPS OF ENGINEERS (USACE):
http://www.swf.usace.army.mil/
INTERNATIONAL BOUNDARY AND WATER COMMISSION:
http://www.ibwc.state.gov/
ACKNOWLEDGMENTS...
THE DROUGHT MONITOR IS A MULTI-AGENCY EFFORT INVOLVING NOAA'S
NATIONAL WEATHER SERVICE AND NATIONAL CLIMATIC DATA CENTER...THE
USDA...STATE AND REGIONAL CENTER CLIMATOLOGIST AND THE NATIONAL
DROUGHT MITIGATION CENTER. INFORMATION FOR THIS STATEMENT HAS
BEEN GATHERED FROM NWS AND FAA OBSERVATION SITES...STATE
COOPERATIVE EXTENSION SERVICES...THE USACE AND USGS.
QUESTIONS OR COMMENTS...
IF YOU HAVE NAY QUESTIONS OR COMMENTS ABOUND THIS DROUGHT
INFORMATION STATEMENT...PLEASE CONTACT...
NATIONAL WEATHER SERVICE
2090 AIRPORT ROAD
NEW BRAUNFELS TEXAS 78130
830-606-3617