HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
158 PM MST FRI FEB 25 2005

...SPRING FLOOD AND WATER RESOURCES OUTLOOK NUMBER 1...

THIS OUTLOOK ENCOMPASSES THE NORTH PLATTE RIVER MAINSTEM AND ITS 
TRIBUTARIES (THE LARAMIE AND MEDICINE BOW RIVERS) IN SOUTHEASTERN 
WYOMING AND THE NEBRASKA PANHANDLE. LIKEWISE IT ALSO INCLUDES THE 
TRIBUTARIES TO THE MISSOURI RIVER (NIOBRARA AND WHITE RIVERS) OF 
EXTREME NORTHWESTERN NEBRASKA.  FINALLY IT ALSO INCLUDES THE LITTLE 
SNAKE RIVER DRAINAGE OF SOUTH CENTRAL WYOMING.

THIS OUTLOOK IS VALID FROM FEBRUARY 25 THROUGH MARCH 10...2005.

  OUTLOOK SUMMARY

NO SNOWMELT FLOODING IS EXPECTED IN SOUTHEASTERN WYOMING OR THE
NEBRASKA PANHANDLE THIS SPRING.  THIS FORECAST IS BASED UPON CURRENT
SNOWPACK CONDITIONS...AND THE EXPECTATION OF CLIMATOLOGICALLY AVERAGE
TEMPERATURE AND PRECIPITATION FROM NOW THROUGH JULY.

  HYDROLOGIC...CLIMATOLOGIC...RESERVOIR...AND RIVER CONDITIONS

CONDITIONS ACROSS SOUTHEASTERN WYOMING AND THE NEBRASKA PANHANDLE IN 2004
WERE...ON AVERAGE BOTH DRIER AND WARMER THAN THE LONG TERM CLIMATOLOGICAL
AVERAGES. FOR EXAMPLE (PRELIMINARY DATA):

CHEYENNE, WY
AVERAGE TEMPERATURE: +1.76 DEG F.
AVG MIN TEMP: +1.28 DEG F
AVG MIN TEMP: +2.33 DEG F
ANNUAL PRECIP TOTAL: -2.10" (AVERAGE 15.14")

LARAMIE, WY
AVERAGE TEMPERATURE: +0.79 DEG F.
AVG MAX TEMP: +0.29 DEG F
AVG MIN TEMP: +1.30 DEG F
ANNUAL PRECIP TOTAL: -0.93" (AVERAGE 10.72")

SCOTTSBLUFF, NE
AVERAGE TEMPERATURE: +0.79 DEG F.
AVG MAX TEMP: +2.11 DEG F
AVG MIN TEMP: +1.59 DEG F
ANNUAL PRECIP TOTAL: -4.41" (AVERAGE 11.65")

SIDNEY, NE
AVERAGE TEMPERATURE: +0.79 DEG F.
AVG MAX TEMP: +3.55 DEG F
AVG MIN TEMP: +3.38 DEG F
ANNUAL PRECIP TOTAL: -0.52" (AVERAGE 15.93")

AND THE CORRESPONDING CLIMATE DATA FOR JANUARY 2005:

CHEYENNE, WY
AVERAGE TEMPERATURE: +6.0 DEG F.
ANNUAL PRECIP TOTAL: -0.04"

LARAMIE, WY
AVERAGE TEMPERATURE: +7.9 DEG F.
ANNUAL PRECIP TOTAL: -0.08"

SCOTTSBLUFF, NE
AVERAGE TEMPERATURE: +3.9 DEG F.
ANNUAL PRECIP TOTAL: +0.12"

SIDNEY, NE
AVERAGE TEMPERATURE: +3.9 DEG F.
ANNUAL PRECIP TOTAL: -0.35"

THE PREVALENT STORM TRACK FOR MUCH OF THE 2005 WINTER SEASON HAS BEEN GENERALLY
FROM SOUTHERN CALIFORNIA THROUGH EASTERN KANSAS...INTO MASSACHUSETTS.
THIS HAS SUPPRESSED THE MAJORITY OF WINTER-TIME PRECIPITATION FAR TO THE SOUTH
OF THE AREA. AS A RESULT THE AMOUNT OF WATER STORED IN MOUNTAIN SNOWPACK (CALLED
THE SNOW WATER EQUIVALENT OR SWE) HAS BEEN JUST AT OR BELOW NORMAL FOR MOST OF
THE WINTER SEASON.

AS OF THIS DATE THE SWE VALUES FOR THE MOUNTAINS OF SOUTHEASTERN WYOMING ARE:

UPPER NORTH PLATTE BASIN (ABOVE SEMINOE RESERVOIR): 102% OF NORMAL
LOWER NORTH PLATTE BASIN (BELOW SEMINOE RESERVOIR):  88%
LITTLE SNAKE BASIN (BAGGS, WYOMING AREA)          : 104%
SOUTH PLATTE BASIN (CHEYENNE AND PANHANDLE AREA)  :  85%

THESE VALUES ARE AS MUCH AS 20-25 PERCENTAGE POINTS LOWER THAN THEIR PEAKS IN
LATE DECEMBER OF LAST YEAR DUE TO THE GENERALLY WARMER WEATHER SINCE THAT TIME.

  RESERVOIR CONDITIONS

ALL OF THE MAJOR UPSTREAM BUREAU OF RECLAMATION RESERVOIRS ON THE NORTH PLATTE RIVER
SYSTEM...THE MAJOR RIVER DRAINAGE IN THIS AREA...ARE STORING MUCH BELOW NORMAL
WATER VOLUMES FOR THIS TIME OF YEAR.  SINCE THE RECORD DRY YEAR OF 2002...STORAGE IN
THE RESERVOIRS ALONG THE NORTH PLATTE HAS DECLINED DUE TO INSUFFICIENT RECHARGE SNOWMELT
WATER EACH SPRING.

RESERVOIR STORAGE VOLUMES AS OF JANUARY 31 2005 ARE:

SEMINOE: 49% OF AVERAGE TOTAL STORAGE, 26% OF TOTAL CAPACITY
PATHFINDER: 39% OF AVERAGE TOTAL STORAGE, 24% OF TOTAL CAPACITY

  RIVER/ICE CONDITIONS

MOST RIVERS AT LOWER (VALLEY) ELEVATIONS ARE MOSTLY FREE OF ICE WITH THEIR
CORRESPONDING HEADWATERS EXHIBITING PARTIAL TO COMPLETE ICE COVER.  STREAMFLOWS ARE
NEAR TO BELOW NORMAL ACROSS THE AREA.

  CLIMATOLOGICAL OUTLOOK AND FORECAST CONDITIONS

THE SOUTHERN WINTER STORM TRACK PATTERN IS FORECAST TO CONTINUE THROUGH THE NEXT 7
TO 14 DAYS.  TEMPERATURES ARE EXPECTED TO REMAIN 2 TO 3 DEGREES F. ABOVE NORMAL.
NO SUBSTANTIAL PRECIPITATION IS EXPECTED DURING THIS PERIOD.

THE LONGER TERM 30 TO 90 DAY GENERAL WEATHER OUTLOOK ALSO FORECASTS THE SOUTHERN
WINTER STORM TRACK TO CONTINUE.  TEMPERATURES ARE EXPECTED TO BE CLIMATOLOGICALLY
AVERAGE TO ABOVE NORMAL.  PRECIPITATION AMOUNTS ARE EXPECTED TO BE AVERAGE AS WELL.

AS A RESULT...ABNORMALLY DRY TO SEVERE DROUGHT CONDITIONS ARE EXPECTED TO PERSIST
ACROSS SOUTHEASTERN WYOMING OR THE NEBRASKA PANHANDLE.

  NEXT OUTLOOK ISSUANCE

THE FINAL SPRING FLOOD AND WATER RESOURCES OUTLOOK FOR 2005 WILL BE ISSUED MARCH 11.
VISIT OUR WEB SITE http://www.crh.noaa.gov/cgi-bin/ahps.cgi?cys FOR MORE WEATHER
AND RIVER INFORMATION INCLUDING REAL TIME GRAPHS OF RIVER FLOW...PRECIPITATION...
AND SNOW WATER EQUIVALENCE.

CYS/RJG