90 percent of Oklahoma and Texas in an exceptional drought, National Weather Service, Norman

 

DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK

…EXCEPTIONAL TO EXTREME DROUGHT COVERS 90 PERCENT OF OKLAHOMA
AND TEXAS…

…LITTLE RELIEF FROM DROUGHT CONDITIONS EXPECTED DURING AUTUMN…

SYNOPSIS…
ACCORDING TO THE U.S. DROUGHT MONITOR…DATED SEPTEMBER 23…
EXCEPTIONAL DROUGHT CONDITIONS COVERED ALL OF WESTERN NORTH
TEXAS AND THE WESTERN TWO-THIRDS OF OKLAHOMA.  IN OKLAHOMA…THE
EXCEPTIONAL DROUGHT AREA IS GENERALLY WEST OF
ATOKA…HOLDENVILLE….STILLWATER AND BLACKWELL.  A GRAPHICAL
DEPICTION OF DROUGHT CONDITIONS MAY BE FOUND ONLINE AT THE NATIONAL
WEATHER SERVICE NORMAN HOMEPAGE AND THE CLIMATE PREDICTION CENTER
(CPC) DROUGHT MONITOR PAGE.

THE U.S. DROUGHT MONITOR USES FIVE CATEGORIES…LABELED D0-D4. FOR
COMPARISON…IN AUGUST OF 2006…EXCEPTIONAL D4 DROUGHT COVERED ALL
OF WESTERN NORTH TEXAS AND FAR SOUTHERN OKLAHOMA. THE CURRENT
DROUGHT SURPASSES THE 2006 DROUGHT FOR AREA COVERED BY BOTH THE D3
AND D4 CATEGORIES.

DROUGHT LEVELS…
D0 — ABNORMALLY DRY OR RECOVERING FROM DROUGHT
D1 — MODERATE DROUGHT
D2 — SEVERE DROUGHT
D3 — EXTREME DROUGHT
D4 — EXCEPTIONAL DROUGHT

CLIMATE SUMMARY…
SINCE LATE AUGUST…MUCH NEEDED RAIN FELL ACROSS THE SOUTHERN
PLAINS BUT MANY AREAS EXPERIENCED BELOW AVERAGE RAINFALL.  IN
GENERALLY…RAINFALL TOTALS FROM LATE AUGUST TO LATE SEPTEMBER
RANGED FROM HALF AN INCH OVER PARTS OF SOUTHWEST OKLAHOMA AND
WESTERN NORTH TEXAS…TO OVER THREE INCHES IN NORTH CENTRAL
OKLAHOMA.  OTHER ISOLATED TWO TO THREE INCH AMOUNTS OCCURRED OVER
FAR SOUTHERN OKLAHOMA AND WICHITA FALLS….TEXAS.  ALTHOUGH SOME
RAIN HAS FALLEN…MANY AREAS HAVE ONLY RECEIVED FIFTY PERCENT OF THE
AVERAGE RAINFALL DURING THE LAST 30 DAYS.  HOWEVER…THE RETURN OF
NEAR AVERAGE TO SLIGHTLY BELOW AVERAGE TEMPERATURES HAS HELPED
REDUCE THE AMOUNT OF EVAPORATION.

THE TABLE BELOW INDICATES THE AVERAGE PRECIPITATION SINCE OCTOBER
1ST, 2010 FOR SEVERAL CLIMATE DIVISIONS IN OKLAHOMA. WICHITA FALLS
PRECIPITATION IS INCLUDED TO ILLUSTRATE HOW DRY PARTS OF WESTERN
NORTH TEXAS HAVE BEEN DURING THE LAST 12 MONTHS.

CLIMATE       TOTAL          DEPARTURE          RANK SINCE
DIVISION  PRECIPITATION     FROM NORMAL            1921
——–     ——–       ———–         ———-
N.CENTRAL     16.09″          -14.62″           2ND DRIEST
W.CENTRAL     12.11″          -16.07″           1ST DRIEST
CENTRAL       18.67″          -18.09″           1ST DRIEST
SOUTHWEST     11.94″          -17.85″           1ST DRIEST
S.CENTRAL     18.37″          -21.29″           2ND DRIEST
STATEWIDE     19.86″          -15.69″           2ND DRIEST

WICHITA FALLS  7.14″          -21.02″           1ST DRIEST

PRECIPITATION/TEMPERATURE OUTLOOK…
THE 6 TO 10 DAY AND 8 TO 14 DAY OUTLOOKS FROM THE CLIMATE PREDICTION
CENTER FORECAST A GREATER LIKELIHOOD OF TEMPERATURE BEING ABOVE
AVERAGE FOR THE SOUTHERN PLAINS. THESE SAME OUTLOOKS PREDICT A
GREATER LIKELIHOOD OF PRECIPITATION BEING BELOW NORMAL.  ALSO FROM
THE CPC…OUTLOOKS FOR ONE AND THREE MONTHS INTO THE FUTURE PLACE A
GREATER LIKELIHOOD ON TEMPERATURE BEING ABOVE NORMAL. THE ONE
AND THREE MONTH OUTLOOKS CALL FOR A BETTER CHANCE OF PRECIPITATION
BEING BELOW NORMAL.   THE OUTLOOK FOR WARMER TEMPERATURES AND
BELOW AVERAGE RAINFALL INTO DECEMBER IS PARTIALLY WEIGHTED ON THE
RETURN OF LA NINA CONDITIONS IN THE TROPICAL PACIFIC OCEAN. 

SUMMARY OF IMPACTS…

FIRE DANGER…
THE EXCEPTIONALLY DRY VEGETATION WILL KEEP MOST AREAS AT A GREATER
RISK OF WILDFIRES THAN NORMAL…ESPECIALLY ACROSS WESTERN OKLAHOMA
AND ADJACENT AREAS OF NORTH TEXAS WHERE HUMIDITY LEVELS ARE
GENERALLY LOWER AND WIND SPEEDS HIGHER.  MUCH OF OKLAHOMA AND
ALL OF NORTH TEXAS HAVE BURN BANS. 

HYDROLOGIC SUMMARY AND OUTLOOK…

MOST RIVERS AND CREEKS IN THE REGION ARE FLOWING AT RATES THAT ARE
BELOW AVERAGE FOR THIS TIME OF YEAR. MOST RIVERS ARE EXHIBITING
7-DAY STREAM FLOW AVERAGES THAT ARE IN THE 10 TO 24 PERCENT (BELOW
NORMAL) RANGE OR LESS THAN 10 PERCENT (WELL BELOW NORMAL) RANGE.
SCATTERED LOCATIONS IN CENTRAL/WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS HAVE NEAR AVERAGE STREAMFLOWS FOR THIS TIME OF THE YEAR.
INFORMATION FROM THE U.S. GEOLOGICAL SURVEY INDICATES THAT A
MODERATE HYDROLOGIC DROUGHT IS TAKING PLACE IN THE CIMARRON RIVER
BASIN IN NORTHERN OKLAHOMA… THE RED RIVER BASIN IN SOUTH CENTRAL
OKLAHOMA… AND THE UPPER WASHITA AND NORTH FORK OF THE RED RIVER
BASINS IN WESTERN OKLAHOMA.

RESERVOIR CONDITIONS AS OF SEPTEMBER 23RD…

LEVELS AT MOST RESERVOIRS IN THE ARKANSAS AND RED RIVER DRAINAGE
AREAS ARE BELOW NORMAL DUE TO THE PROLONGED DROUGHT CONDITIONS. MOST
RESERVOIRS RANGE FROM ABOUT 1 TO 27 FEET BELOW THEIR NORMAL
POOLS…OR ABOUT 5 TO 83 PERCENT BELOW THEIR NORMAL STORAGE
CAPACITIES. BELOW IS A LIST OF RESERVOIRS WITH THE LATEST ELEVATIONS
AND NORMAL POOLS.

———————————————————————-
                         TOP OF      POOL    
RESERVOIR                NORMAL      ELEV.   
                          POOL             
                        (FT MSL)    (FT MSL)
———————————————————————

*** ARKANSAS RIVER BASIN ***

GREAT SALT PLAINS LAKE   1125.0     1123.36  
* KAW LAKE               1009.0     1008.61
FORT SUPPLY LAKE         2004.0     2004.32  
LAKE HEFNER              1199.0     1189.30  
CANTON LAKE              1615.4     1609.95  
LAKE OVERHOLSER          1242.0     1232.75  
ARCADIA LAKE             1006.0     1004.10  

*** RED RIVER BASIN ***

ALTUS LAKE               1559.0     1532.07  
TOM STEED LAKE           1411.0     1404.82  
LAKE KEMP                1144.0     1129.70  
LAKE KICKAPOO            1045.0     1037.33  
LAKE ARROWHEAD            926.4      918.11  
WAURIKA LAKE              951.4      947.56  
FOSS LAKE                1642.0     1637.56  
FORT COBB LAKE           1342.0     1339.12  
ARBUCKLE LAKE             872.0      867.22  
LAKE TEXOMA               615.0      611.48  
ATOKA LAKE                590.0      584.26  
MCGEE CREEK LAKE          577.1      575.06

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