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Omaha/Valley Hydrologic Outlook #2

…SPRING FLOOD AND WATER RESOURCES OUTLOOK NUMBER 2…

THIS FLOOD OUTLOOK IS FOR THE NATIONAL WEATHER SERVICE OMAHA AREA.
THIS AREA INCLUDES EASTERN NEBRASKA AND PORTIONS OF SOUTHWEST IOWA.
IT INCLUDES PORTIONS OF THE FOLLOWING RIVERS AND THEIR
TRIBUTARIES…

MISSOURI RIVER FROM DECATUR TO RULO
NIOBRARA RIVER
BIG BLUE RIVER
ELKHORN RIVER FROM NELIGH TO THE PLATTE RIVER CONFLUENCE
PLATTE RIVER FROM DUNCAN TO LOUISVILLE

…CURRENT FLOOD OUTLOOK HIGHLIGHTS…

* THE RISK OF FLOODING FOR THE REMAINDER OF WINTER AND INTO MID
SPRING IS BELOW NORMAL AT MOST LOCATIONS. LOCALLY HEAVY
SPRING RAINS WILL CAUSE FLOODING IN LOCALIZED AREAS AS IS
THE CASE EVERY YEAR. THIS OUTLOOK IS DIRECTED TOWARDS FLOODING ON
A LARGER SCALE.

* CURRENT CONDITIONS ARE NOT CONDUCIVE TO MAJOR…LARGE-SCALE
FLOODING.

* GRAPHICS FOR SELECT RIVER GAUGES ARE AVAILABLE ON OUR WEBSITE
AT: WATER.WEATHER.GOV/AHPS2/INDEX.PHP?WFO=OAX, ONCE A GAUGE IS
SELECTED CLICK ON THE GRAPH AND CHOOSE “CHANCE OF EXCEEDING LEVELS
DURING ENTIRE PERIOD.”

OVERVIEW…BASED ON CURRENT CONDITIONS THERE IS A LOW THREAT FOR
SPRING FLOODING ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA. THE
PRIMARY REASON FOR THIS IS A LACK OF APPRECIABLE SNOW COVER…DRIER
THAN NORMAL SOIL MOISTURE CONDITIONS…AND LOWER THAN NORMAL FALL
PRECIPITATION. THIS WEEKEND A STRONG STORM SYSTEM WILL MOVE THROUGH
THE CENTRAL PLAINS. THIS SYSTEM COULD BRING UP TO ONE INCH OF LIQUID
EQUIVALENT PRECIPITATION TO OUR AREA. THIS PRECIPITATION IS MUCH
NEEDED AS THE AREA IS ALSO EXPERIENCING A SEVERE DROUGHT. WHILE THIS
WILL NOT BE ENOUGH TO ELIMINATE THE DROUGHT IT IS CERTAINLY A STEP IN
THE RIGHT DIRECTION.

MOUNTAIN SNOW PACK…FOR THE MISSOURI RIVER SNOW WATER EQUIVALENT
VALUES ARE 97% OF NORMAL THROUGH MARCH 7. FOR THE PLATTE RIVER
SNOW WATER EQUIVALENT VALUES ARE 74% OF NORMAL.

PLAINS SNOW PACK…ACROSS NEBRASKA AND WESTERN IOWA THE CURRENT
SNOW PACK IS NEGLIGIBLE. ACROSS THE DAKOTAS SNOW WATER EQUIVALENT
VALUES RANGE FROM 1 TO 4 INCHES WITH THE HIGHEST AMOUNTS FOCUSED
IN THE JAMES AND BIG SIOUX RIVER BASINS.

ICE JAM THREAT…THIS YEAR THE THREAT FOR ICE JAM FLOODING IS LOW.
RIVER ICE THICKNESS HAS BEEN MINIMAL THIS WINTER AND WHAT ICE DID
FORM EARLY IN THE WINTER HAS ALREADY FLUSHED OUT OR MELTED. THE
LOWER PLATTE RIVER FLUSHED ITS ICE OUT THE WEEKEND OF FEBRUARY 9TH
AND THE ELKHORN ON THE 13TH OF FEBRUARY. THIS MEANS FOR ICE JAMS TO
OCCUR WE ARE ESSENTIALLY STARTING OVER…MORE OR LESS…AND GIVEN
THE LIMITED TIME LEFT FOR COLD WEATHER, THE ICE JAM THREAT IS LOW.

FROST DEPTHS…VALUE ARE AVERAGING AROUND 6 INCHES ACROSS THE AREA.

CURRENT RIVER CONDITIONS…RIVERS ACROSS THE AREA ARE GENERALLY BELOW
NORMAL. SINCE THE LAST OUTLOOK SOME IMPROVEMENT HAS OCCURRED…DESPITE
THIS IMPROVEMENT HOWEVER MOST RIVER BASINS ARE BELOW THEIR LONG TERM
AVERAGES. SEVERAL RIVER LOCATIONS ARE SUMMARIZED IN THE SUB-SECTIONS BELOW.

CLIMATE OUTLOOK FOR MARCH THROUGH MAY…THE CLIMATE PREDICTION
CENTER INDICATES A 40 TO 50 PERCENT CHANCE FOR TEMPERATURES TO REACH
THE ABOVE NORMAL THIRD ACROSS THE AREA COMPARED TO 1981 TO 2010
CLIMATOLOGY. THIS LEAVES A 33 PERCENT CHANCE FOR TEMPERATURES TO
REACH THE NEAR NORMAL THIRD…AND A 17 TO 27 PERCENT CHANCE FOR
TEMPERATURES IN THE BELOW NORMAL THIRD. THE CLIMATE PREDICTION
CENTER ALSO INDICATES EQUAL CHANCES FOR PRECIPITATION THIS SPRING TO
BE IN THE ABOVE…NEAR…AND BELOW NORMAL CATEGORIES FOR THE SPRING.

THE TEMPERATURE OUTLOOK FOR MARCH DOES INCLUDE A 33 TO 40 PERCENT
CHANCE FOR CONDITIONS SIMILAR TO THE COOLEST THIRD OF 1981 TO 2010
CLIMATOLOGY IN WESTERN IOWA. EQUAL CHANCES IS FORECAST FOR MARCH
PRECIPITATION IN EASTERN NEBRASKA.

THE SUB-SECTIONS BELOW SUMMARIZE CURRENT RIVER CONDITIONS ACROSS
EASTERN NEBRASKA AND WESTERN IOWA.