Flash Flood in Nebraska, June 13 to 14, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
311 PM CDT SUN JUN 13 2010

.DISCUSSION...

HEAVY RAINFALL THE PAST 7 DAYS HAS BEEN EXTREME. AMOUNTS RANGE FROM
1.5 TO 2 INCHES IN CHASE COUNTY TO 4 TO 8 INCHES
MCPHERSON...LOGAN...HOOKER...THOMAS...SOUTHERN CHERRY...BROWN...
ROCK...BOYD...HOLT...BLAINE...LOUP...GARFIELD...WHEELER...AND
NORTHERN CUSTER COUNTY. THIS ENCOMPASSES ABOUT HALF THE THE FORECAST
AREA. LOCALLY 10 INCHES HAVE BEEN OBSERVED FROM NEAR BREWSTER AND
TAYLOR NORTHEAST TO NEAR ONEILL. IT IS LIKELY DECADES SINCE RAINFALL
OF THIS MAGNITUDE HAS IMPACTED THE FORECAST AREA IN ONLY A WEEK
PERIOD.

REGIONAL RADAR MOSAIC INDICATED CONVECTION FIRING UP ALONG
APPROACHING DISTURBANCE FROM NEAR AKRON CO THROUGH GARDEN CITY KS.
WIDESPREAD SHOWERS AND STORMS ONGOING NERN CO INTO THE NEBR PNHDL
AND SERN WY IN VICINITY OF UPPER LOW NOW LOCATED ACROSS NWRN CO.
KLNX RADAR SHOWS DEEP EASTERLY FROM SFC TO 10K FEET AGL WITH DEEP
VEERING PROFILE. 12Z U/A SOUNDING...PWS 173 PERCENT OF NORMAL AT
KLBF AND 152 PERCENT AT KDEN INDICATED DEEP MOISTURE STILL
AVAILABLE. PREFERRED MODEL IS ACTUALLY THE REGIONAL GEM MODEL WRT
PREVIOUS PRECIPITATION PLACEMENT AND LOCATION OF CURRENT
DEVELOPMENT. SHOWERS EXPECTED TO BECOME CATEGORICAL WITH WIDESPREAD
ACROSS SWRN NEBR LATE THIS AFTN AND EARLY EVENING...SPREADING
NORTHEAST OVERNIGHT. 12HR QPFS EXPECTED TO RANGE FROM A HALF INCH TO
ONE INCH. SOME AREAS WILL HOPEFULLY BE LESS...ALTHOUGH ANY
CONVECTIVE CLUSTER COULD YIELD LOCAL AMOUNTS UP TO 2 INCHES. THIS
WILL LIKELY ATTRIBUTE TO ADDITIONAL FLOODING IN ALREADY FLOODED
AREAS. MANY ROADS HAVE BECOME WASHED OUT OR COVER WITH WATER AND
SOME BRIDGES ALSO CLOSED.

ON MONDAY...UPPER LOW FCST TO DEEPEN INTO NWRN SOUTH DAKOTA WITH A
CONTINUED THREAT FOR SCATTERED SHOWERS AND TSTMS. RAINFALL AMOUNTS
HOWEVER SHOULD BE A QUARTER INCH OR LESS AND LACK IN COVERAGE...SO
SOME AREAS SHOULD BEGIN TO IMPROVE...EXCEPT FOR MANY RIVERS WHICH
WILL STILL BE ON THE RISE. WILL KEEP A SLIGHT CHC MONDAY NIGHT AS
UPPER LOW SWINGS EAST INTO ERN SOUTH DAKOTA AND MINNESOTA.

DRIER AND SEASONABLE CONDITIONS TO SET IN TUESDAY THROUGH SUNDAY.
STILL AT LEAST A SLIGHT CHANCE FOR TSTMS LATE TUESDAY NIGHT THROUGH
THURSDAY NIGHT AS ANOTHER UPPER TROUGH DIGS FROM THE PAC NW INTO WY
AND ERN MONTANA. THIS UPPER LOW FCST TO TRACK FURTHER NORTHWEST AND
NOT SET UP LIKE CURRENT SYSTEM HAS. A MENTION AGAIN SATURDAY AND
SATURDAY NIGHT AS AN UPPER RIDGE BUILDS IN FROM THE SRN PLAINS AND
SFC LOW IN NRN KS WITH TSTMS POSSIBLE NORTH OF THE FROM ACROSS NEBR.

&&

.AVIATION...
MIXTURE OF LOW END MVFR AND IFR CONDITIONS IN PLACE ACROSS WESTERN
AND NORTH CENTRAL NEBRASKA THIS AFTERNOON. ONE BATCH OF PCPN MOVING
OUT OF NORTH CENTRAL NEB AND NEW DEVELOPMENT ACROSS THE SOUTHWEST.
AS THIS NEW BATCH OF PCPN SHOULD MOVE ACROSS CWA THROUGH THE NITE
LEADING TO RESTRICTIONS TO VSBYS FROM RAIN AND FOG WHILE LOWERED
CIGS SHOULD PERSISTS. FOR KLBF AND KVTN TERMINALS EXPECT IFR FLIGHT
RULES TO BE THE MOST PERSISTENT THOUGH LIFR WOULD NOT BE OUT OF
QUESTION IN THE HEAVIER RAIN SHOWERS. DRIER AIR MOVING IN
ALOFT...BEHIND THE AREA OF PCPN...MAY LEAD TO LOWERING CIGS AND FOG
IN SW NEB TOWARD MORNING. LIFR WOULD MOST LIKELY BECOME MORE
WIDESPREAD...BUT CONFIDENCE TOO LOW ATTM TO PLACE IN TAF AND WILL
CONTINUE TO MONITOR.

&&

.HYDROLOGY...
MAJOR CONCERNS ABOUT AREA HYDROLOGIC CONDITIONS PERSIST THIS
AFTERNOON. ELKHORN RIVER IS AT RECORD LEVELS ATTM AND HYDROGRAPH
SHOWS NO TREND IN SLOWING. SOUTH FORK OF THIS RIVER ALSO RUNNING
HIGH AND HAVE SOME CONCERN ABOUT THE CONFLUENCE NEAR EWING. THIS
RIVER ALREADY HAS TWO MAJOR HIGHWAYS CLOSED. THE OTHER MAJOR RIVERS
IN THE NORTH CENTRAL SEEM TO BE HOLDING OR IN DECLINE ATTM THOUGH
THE CALAMUS RIVER IS ON THE RISE DUE TO EMERGENCY RELEASES OF UP TO
1K CFS FROM VIRGINIA SMITH...BUT NO PROBLEMS ARE ANTICIPATED BY
LOCAL WATER MANAGEMENT PERSONNEL. THE BIGGER PROBLEM IN THE NORTH
CENTRAL ATTM IS THE RUNOFF OVER THE SMALLER WATERSHEDS WITH MANY
SMALL CREEKS OR DRAWS SENDING WATER OVER AND THROUGH ROADWAYS WITH
NUMEROUS BRIDGES ALREADY COMPROMISED.
ACROSS SOUTHWEST NEBRASKA MAJORITY OF THE RIVERS/STREAMS ARE IN
RETREAT AS WELL WITH THE EXCEPTION BEING THE RED WILLOW CREEK
FLOWING INTO RED WILL RES WHICH HAS SHOWN A STEADY INCREASE OF 8FT
OVER THE PAST 12 HOURS OR SO. AND FINALLY THE NORTH PLATTE RIVER
CONTINUES OUT OF THE BANKS NEAR LEWELLEN BUT CONDITIONS HAVE
IMPROVED AT BOTH LISCO AND NORTH PLATTE TO DROP FLOOD WARNING
ATTM.
SATELLITE AND 88D MOSAIC SHOW THE NEXT ROUND OF PCPN FORMING FROM
WESTERN KS INTO NORTHEAST COLORADO. THIS AREA OF PCPN SHOULD
CONTINUE TO CONGEAL THROUGH THE AFTERNOON AND LIFT ACROSS THE CWA
OVERNIGHT AS THE MAIN UPPER BEGINS TO SHIFT OUT OF THE ROCKIES INTO
THE HIGH PLAINS. PWATS RUNNING 150 PERCENT OR HIGHER ABOVE NORMAL
ACROSS THE REGION WITH WATER VAPOR/GOES DPI TPW STILL SHOWING
TROPICAL TAP. THEREFORE EXPECT SOME OF THE CONVECTION COULD CONTAIN
HVY RAINFALL RATES AGAIN WITH WIDESPREAD 1 INCH AMOUNTS POSSIBLE
ACROSS MUCH OF THE FORECAST AREA. WORSE CASE SCENARIO WOULD BE AREAS
OF 2 INCH AMOUNTS.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH REMAIN IN EFFECT
THROUGH MONDAY MORNING NEZ004-022>025-035>038-056>059-069>071-094.

&&

DISCUSSION...ROBERG
AVIATION...13
HYDROLOGY...13

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORTH PLATTE NE
348 PM CDT SUN JUN 13 2010

NEZ004>010-022>029-035>038-056>059-069>071-094-142100-
SHERIDAN-EASTERN CHERRY-KEYA PAHA-BOYD-BROWN-ROCK-HOLT-GARDEN-
GRANT-HOOKER-THOMAS-BLAINE-LOUP-GARFIELD-WHEELER-ARTHUR-MCPHERSON-
LOGAN-CUSTER-DEUEL-KEITH-PERKINS-LINCOLN-CHASE-HAYES-FRONTIER-
WESTERN CHERRY-
348 PM CDT SUN JUN 13 2010 /248 PM MDT SUN JUN 13 2010/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN AND
NORTH CENTRAL NEBRASKA.

.DAY ONE...TONIGHT.

THE UPPER LEVEL LOW OVER THE GREAT BASIN WHICH HAS PRODUCED
FLOODING RAINS OVER THE PAST 4 DAYS WILL LIFT NORTH THROUGH THE
CENTRAL AND NORTHERN PLAINS TONIGHT. THIS WILL BRING ANOTHER ROUND
OF RAINFALL TO WESTERN AND NORTH CENTRAL NEBRASKA OVERNIGHT. WITH
THE VERY MOIST AIR MASS STILL IN PLACE HEAVY RAINFALL CAN NOT BE
RULED OUT. GENERALLY RAINFALL AMOUNTS OVERNIGHT SHOULD BE IN THE
1/2 TO 3/4 INCH RANGE...HOWEVER ISOLATED AREAS MAY RECEIVE OVER AN
INCH OF NEW PRECIPITATION THROUGH THE NIGHT. MAJOR FLOODING HAS
OCCURRED AND THE ADDITIONAL RAIN TONIGHT WILL MOST LIKELY LEAD TO
ADDITIONAL PROBLEMS FOR AREA ROADWAYS AND RIVERS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

RAINFALL WILL BEGIN TO TAPER OFF THROUGH THE DAY ON MONDAY...WITH
ONLY LIGHT AMOUNTS OF PRECIPITATION EXPECTED. THIS MAY ALLOW SOME
OF THE SMALLER WATERSHEDS TO RECOVER AS RUNOFF MOVES INTO THE
BIGGER RIVER SYSTEMS. AS A RESULT THE LARGER RIVER
SYSTEMS...ESPECIALLY ALONG THE ELKHORN AND NORTH PLATTE
RIVER...WILL REMAIN TO RUN AT ELEVATED TO OUT OF BANK CONDITIONS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED ON DAMS AND WATERWAYS.

&&

THIS PRODUCT IS NOW AVAILABLE...ALONG WITH OTHER WEATHER...
HYDROLOGICAL AND CLIMATOLOGICAL INFORMATION...AT
HTTP://WWW.WEATHER.GOV/NORTHPLATTE

13

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
515 PM CDT SUN JUN 13 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0505 PM     HEAVY RAIN       NORTH PLATTE            41.13N 100.77W
06/13/2010  M1.61 INCH       LINCOLN            NE   NWS EMPLOYEE

&&

MBYRD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
539 PM CDT SUN JUN 13 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0530 PM     FLOOD            1 NNE HAMLET            40.40N 101.23W
06/13/2010                   HAYES              NE   EMERGENCY MNGR

            STINKING WATER CREEK IS OVERFLOWING BANKS AND OVER HAMLET
            ROAD.

&&

MBYRD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
615 PM CDT SUN JUN 13 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0530 PM     FLOOD            ARNOLD                  41.42N 100.19W
06/13/2010                   CUSTER             NE   EMERGENCY MNGR

            THE MIDDLE LOOP NEAR ARNOLD IS OVERFLOWING BANKS AND
            WATER WAS COVERING PORTIONS OF THE TENNIS COURT.

&&

MASEK