Drought Information Statement
Issued by NWS Riverton, WY

000
AXUS75 KRIW 120103
DGTRIW
WYC003-013-017-019-023-025-029-033-035-037-039-041-043-110115-

DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
703 PM MDT SAT MAY 11 2013

...EXCEPTIONAL/EXTREME DROUGHT CONDITIONS CONTINUED TO RECEDE ACROSS WEST
AND CENTRAL WYOMING IN EARLY MAY...

SYNOPSIS...

SIGNIFICANT SNOWFALL FROM THREE MAJOR SNOWSTORMS ACROSS CENTRAL
AND EASTERN WYOMING RESULTED IN SOME IMPROVEMENT IN THE HARDEST
HIT AREAS WITH EXTREME OR EXCEPTIONAL DROUGHT SINCE LAST AUTUMN.
THE WET APRIL HELPED REDUCE WATER YEAR PRECIPITATION
DEFICITS...ESPECIALLY ACROSS FREMONT AND NATRONA COUNTIES.

THE LATEST DROUGHT MONITOR RELEASED ON MAY 9TH SHOWED NO AREAS IN
EXCEPTIONAL /D4/ DROUGHT...THAT COVERED MOST OF GOSHEN...NIOBRARA
AND WESTON COUNTY AT THE BEGINNING OF APRIL.

EXTREME /D3/ DROUGHT REMAINED ACROSS MOST OF THE BIG HORN
BASIN...PORTIONS OF EASTERN WYOMING (MAINLY CONVERSE AND NIOBRARA
COUNTIES) AND ACROSS CENTRAL CARBON COUNTY. EXTREME DROUGHT
CONDITIONS HAD RETREATED COMPLETELY OUT OF NATRONA AND JOHNSON
COUNTIES.  SEVERE /D2/ DROUGHT OR WORSE STILL COVERED OVER 78.7
PERCENT OF WYOMING.

HERE ARE THE DROUGHT CONDITIONS BEFORE AND AFTER THE APRIL SNOWS
FOR WYOMING...

APRIL 2ND
83.7 PERCENT OF STATE IN SEVERE /D2/ DROUGHT OR WORSE
54.9 PERCENT OF STATE IN EXTREME /D3/ DROUGHT OR WORSE
10.1 PERCENT OF STATE IN EXCEPTIONAL DROUGHT

MAY 9TH
78.7 PERCENT OF STATE IN SEVERE /D2/ DROUGHT OR WORSE
13.9 PERCENT OF STATE IN EXTREME /D3/ DROUGHT OR WORSE
ZERO PERCENT OF STATE IN EXCEPTIONAL DROUGHT

HOWEVER...WYOMING HAS A LONG WAY TO GO TO RECOVER FROM THE DROUGHT
THAT CREEPED INTO THE SOUTH IN EARLY 2013 AND EXPANDED RAPIDLY AND
WORSENED THROUGH JUNE AND JULY 2013. FROM MARCH 2013 GOING BACK TO
NOVEMBER 2012...WYOMING HAS HAD FIVE CONSECUTIVE 12 MONTH PERIODS
RANKING AS THE DRIEST ON RECORD SINCE 1895. APRIL 2013 MAY FINALLY
BREAK THIS STREAK...BUT WE STILL NEED SEVERAL MORE WET MONTHS TO
BREAK THE CURRENT DROUGHT. THE OUTLOOKS FOR THE NEXT FEW MONTHS DO
NOT LOOK VERY PROMISING.

PERIOD             STATEWIDE AVG     20TH CENTURY     RANK
                   PRECIP (IN)       AVG (IN)         (OUT OF
                                                      119 YEARS)

APR 2012-MAR 2013      7.71          13.16             1ST DRIEST
MAR 2012-FEB 2013      7.64          13.16             1ST DRIEST
FEB 2012-JAN 2013      7.90          13.16             1ST DRIEST

JAN-DEC 2012           8.08          13.17             1ST DRIEST

DEC 2011-NOV 2012      8.04          13.17             1ST DRIEST
NOV 2011-OCT 2012      8.32          13.16             2ND DRIEST
OCT 2011-SEP 2012      8.97          13.16             3RD DRIEST
SEP 2011-AUG 2012      9.03          13.16             3RD DRIEST
AUG 2011-JUL 2012      9.57          13.16             4TH DRIEST
JUL 2011-JUN 2012      9.47          13.16             5TH DRIEST
APR 2011-MAY 2012     10.42          13.15            13TH DRIEST

SUMMARY OF IMPACTS...

RIVER AND STREAMFLOW CONDITIONS.

STREAMFLOW SNOWMELT VOLUMES ARE EXPECTED TO BE BELOW NORMAL ACROSS
A MAJORITY OF BASINS ACROSS CENTRAL AND SOUTHERN WYOMING. ABOVE
NORMAL (105 TO 120 PERCENT) SNOWMELT RUNOFF VOLUMES ARE EXPECTED
ACROSS A MAJORITY OF HEADWATER STREAMS ALONG THE POWDER RIVER
BASIN. THE REST OF THE MAJOR BASINS IN NORTHERN WYOMING ARE
FORECASTED TO SEE NEAR NORMAL STREAMFLOW VOLUMES THIS SPRING AND
SUMMER.

FIRE WEATHER IMPACTS.

NO FUELS WERE CLASSIFIED AS CRITICAL IN ANY AREAS ACROSS WEST AND
CENTRAL WYOMING. MOST VEGETATION IN THE LOWER ELEVATIONS WAS IN
GREEN UP WITH SNOW-COVERED OR WET FUELS FROM MELTING SNOW
PREVAILING IN THE HIGHER ELEVATIONS. CONTACT YOUR LOCAL COUNTY
OFFICIALS FOR THE LATEST BURNING RESTRICTIONS.

THE SIGNIFICANT WILDLAND FIRE POTENTIAL OUTLOOK SHOWED NORMAL
CONDITIONS DURING JULY AND AUGUST 2013. WILDLAND FIRES ARE STILL
EXPECTED TO OCCUR DURING FORECASTED NORMAL CONDITIONS AS WOULD
USUALLY BE EXPECTED DURING THE OUTLOOK PERIOD.

CLIMATE SUMMARY...

PORTIONS OF FREMONT AND NATRONA COUNTY RECEIVED 150 TO 200 PERCENT
OF NORMAL PRECIPITATION IN APRIL...HELPING TO CLOSE DEFICITS FOR
THE CURRENT WATER YEAR. THE WET APRIL IN LANDER (3.14 INCHES OR 168
PERCENT OF NORMAL)...AND CASPER (2.54 INCHES OR 197 PERCENT OF
NORMAL) PUSHED THEIR WATER YEAR PRECIPITATION TOTALS TO ABOVE
NORMAL. BELOW ARE THE CUMULATIVE PRECIPITATION AMOUNTS FROM
SELECTED LOCATIONS ACROSS WEST AND CENTRAL WYOMING FOR THE CURRENT
WATER YEAR...OCTOBER 2012 THROUGH APRIL 2013.

LOCATION                   PRECIPITATION             % AVERAGE
                           OCT 2012-APR 2013
--------                   -------------             -----------

AIRPORTS

* BIG PINEY                      0.87                      33
* BUFFALO                        3.12                      64
* CASPER                         5.60                     101
^ EVANSTON                       4.03                      68
+ GREYBULL                       1.29                      48
* LANDER                         7.11                     105
* RIVERTON                       3.13                      77
* ROCK SPRINGS                   0.32 (M)                   M
* SHERIDAN                       6.83                     107
+ WORLAND                        2.69                      89

M - ROCK SPRINGS MISSING PCPN DATA DEC 26 2012-APR 23 2013.

COOPERATIVE OBSERVER STATIONS

^ AFTON                          9.85                     101
* BILLY CREEK                    3.59 (M)                  83
* BITTER CREEK 4 NE              2.51                      82
* FOSSIL BUTTE
  NATIONAL MONUMENT              6.00                     106
* GREEN RIVER                    4.87                     122
* JEFFREY CITY                   4.27                      90
  MOOSE                         12.86                      90
  OLD FAITHFUL                  14.88                      95
* POWELL FIELD STATION           1.38                      69
* RIVERTON (DOWNTOWN)            3.54                      97
* THERMOPOLIS                    3.63                      64

+ LOCATION IN EXTREME DROUGHT /D3/
* LOCATION IN SEVERE DROUGHT /D2/
^ LOCATION IN MODERATE DROUGHT /D1/
(M) MISSING PRECIPITATION DATA IN RECORD

PRECIPITATION/TEMPERATURE OUTLOOKS...

THE ONE MONTH AND THREE MONTH OUTLOOKS WILL BE UPDATED ON THE
THIRD THURSDAY OF THE CURRENT MONTH FOR THE NEXT MONTH AND THREE
MONTH OUTLOOKS.

THE MAY OUTLOOK CALLS FOR A BETTER THAN EVEN CHANCE OF ABOVE
NORMAL TEMPERATURES WEST OF THE DIVIDE AND EQUAL CHANCES OF
ABOVE...BELOW OR NORMAL TEMPERATURES ACROSS CENTRAL AND EASTERN
WYOMING. THE MAY OUTLOOK FOR PRECIPITATION SHOWS A BETTER THAN
EVEN CHANCE OF BELOW NORMAL PRECIPITATION ACROSS MOST OF CENTRAL
AND NORTHWEST WYOMING. NO CLEAR CLIMATE SIGNAL FOR ABOVE...BELOW
OR NORMAL PRECIPITATION WAS OBSERVED ACROSS SOUTHERN AND EASTERN
WYOMING.

THE THREE MONTH OUTLOOK FOR MAY...JUNE AND JULY SHOWS A GREATER
THAN EQUAL CHANCE OF ABOVE NORMAL TEMPERATURES ACROSS ALL OF
WYOMING WITH THE BEST CHANCE ACROSS THE SOUTHERN HALF OF THE
STATE.  THE PRECIPITATION OUTLOOK FOR THIS THREE MONTH PERIOD
SHOWS A BETTER THAN EQUAL CHANCE FOR BELOW NORMAL PRECIPITATION
ACROSS ALL BUT THE EXTREME NORTHEAST CORNER OF WYOMING. THE BEST
CHANCE FOR BELOW NORMAL PRECIPITATION EXISTS OVER SOUTHWEST
WYOMING...OR MAINLY UINTA AND SWEETWATER COUNTIES.

DEVELOPMENT OF EL NINO CONDITIONS STALLED OUT IN SEPTEMBER IN THE
PACIFIC OCEAN. ENSO NEUTRAL CONDITIONS WERE OBSERVED DURING
WINTER 2012-13 THROUGH THIS SPRING. ENSO-NEUTRAL CONDITIONS ARE
EXPECTED TO CONTINUE INTO LATE SUMMER 2013.

THE U.S. SEASONAL DROUGHT OUTLOOK RELEASED ON MAY 2ND SHOWED THAT
SOME IMPROVEMENT IN DROUGHT CONDITIONS IS EXPECTED TO CONTINUE
ACROSS FAR EASTERN WYOMING THROUGH THE END OF JULY. DROUGHT
CONDITIONS ARE EXPECTED TO PERSIST ACROSS OTHER AREAS IN WYOMING
CURRENTLY CURRENTLY CLASSIFIED WITH DROUGHT CONDITIONS.

HYDROLOGIC SUMMARY AND OUTLOOK...

SNOWPACK DATA FOR MAY 11TH -

DRAINAGE BASIN       PERCENT OF AVERAGE             PERCENT CHANGE
                     SNOW WATER EQUIVALENT          SINCE APRIL 25TH
                     (BASED ON 1981-2010 NORMALS)

SNAKE RIVER                   76                        -28
MADISON                       77                        -20
YELLOWSTONE                   80                        -23
WIND RIVER                    85                        -13
BIG HORN BASIN                99                        -16
SHOSHONE RIVER                87                        -13
POWDER                       112                        -12
TONGUE                        89                        -16
BELLE FOURCHE                 NA                         NA
CHEYENNE                      NA                         NA
UPPER NORTH PLATTE            86                        -12
SWEETWATER                    72                        -13
LOWER NORTH PLATTE            81                        -17
LARAMIE                      103                        - 3
SOUTH PLATTE                 103                        -30
LITTLE SNAKE RIVER            73                        -30
UPPER GREEN                   70                        -27
LOWER GREEN                  105                        -22
UPPER BEAR                    65                        -37
_____________________________________________

RESERVOIR DATA FOR MAY 10TH -

RESERVOIR                 PERCENT FULL

CENTRAL WYOMING
BOYSEN                      70.8
BUFFALO BILL                64.3
BULL LAKE                   53.3
PATHFINDER                  39.3

UPPER GREEN RIVER BASIN
BIG SANDY                   31.0
FONTENELLE                  37.0
FLAMING GORGE               80.0

UPPER SNAKE RIVER BASIN
GRASSY LAKE                 90.0
JACKSON LAKE                81.0

NEXT ISSUANCE DATE...

THIS PRODUCT WILL BE UPDATED ON MAY 24 2013 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 /USE LOWER CASE LETTERS/...

TO REPORT EFFECTS OF THE DROUGHT IN YOUR AREA...PLEASE GO TO THE
DROUGHT IMPACT REPORTER AT...

HTTP://DROUGHTREPORTER.UNL.EDU/

...AND CLICK ON SUBMIT A REPORT.

INFORMATION FOR THE MEDIA MAY BE FOUND AT...
HTTP://DROUGHT.UNL.EDU/NEWSOUTREACH/INFORMATIONFORMEDIA.ASPX

NWS RIVERTON DROUGHT PAGE...
HTTP://WWW.CRH.NOAA.GOV/RIW/?N=DROUGHT

USGS WYOMING DROUGHT WATCH...
HTTP://WY.WATER.USGS.GOV/PROJECTS/DROUGHT/

U.S. DROUGHT MONITOR...HTTP://WWW.DROUGHT.GOV

NOAA DROUGHT PAGE...HTTP://WWW.DROUGHT.NOAA.GOV

CLIMATE PREDICTION CENTER /CPC/...HTTP://WWW.CPC.NCEP.NOAA.GOV

ADDITIONAL RIVER AND RESERVOIR INFORMATION...

NWS ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/...
HTTP://WWW.WATER.GOV/AHPS2/INDEX.PHP?WFO=RIW

NRCS WYOMING...HTTP://WWW.WY.NRCS.USDA.GOV

USGS...HTTP://WATER.USGS.GOV/

USBR...HTTP://WWW.USBR.GOV/

WATER RESOURCE DATA SYSTEM (WRDS)...HTTP://WWW.WRDS.UWYO.EDU

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 CLIMATOLOGISTS AND THE NATIONAL
DROUGHT MITIGATION CENTER. INFORMATION FOR THIS STATEMENT HAS BEEN
GATHERED FROM NWS AND FAA OBSERVATION SITES...STATE COOPERATIVE
EXTENSION SERVICES...THE USDA...USACE AND USGS.

QUESTIONS OR COMMENTS...

IF YOU HAVE ANY QUESTIONS OR COMMENTS ABOUT THIS DROUGHT INFORMATION
STATEMENT...PLEASE CONTACT...

ARTHUR MEUNIER
CLIMATE/DROUGHT FOCAL POINT
NATIONAL WEATHER SERVICE
12744 WEST US HIGHWAY 26
RIVERTON, WY  82501
TELEPHONE...307-857-3898
............800-211-1448
EMAIL...ARTHUR.MEUNIER@NOAA.GOV

$$