Flood in Nebraska, June 15 to 16, 2004

AREA FORECAST DISCUSSION...COR FOR FLOOD WATCH TIMES
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
333 AM CDT TUE JUN 15 2004

.DISCUSSION...
MAIN CONCERNS ARE THE CONTINUATION OF SEVERE WEATHER AND THE
FLOODING POTENTIAL.

SHORT TERM...STORMS CONTINUE TO MOVE EWD OVER SRN NEB THIS MORNING
NEAR STATIONARY BOUNDARY EXTENDING WEST TO EAST ACROSS NRN KS AND
MO. NOCTURNAL LOW LEVEL JET HELPING TO KEEP THINGS GOING WITH
ACTIVITY SHIFTING EASTWARD THROUGHOUT THE EARLY MORNING. OTHER AREA
OF CONCERN IS ACROSS SOUTH CENTRAL SOUTH DAKOTA AND NORTH CENTRAL
NEBRASKA WHERE SCATTERED CONVECTION IS ONGOING IN AREA OF STRONG
ISENTROPIC LIFT BEST NOTED AT 310K SURFACE. ALSO HELPING GENERATE
LIFT IS WEAK SHORTWAVE MOVING OUT OF EASTERN WYOMING EMBEDDED IN
WESTERLY MID LEVEL FLOW.

COLD FRONT EXTENDING FROM WESTERN DAKOTAS SOUTH INTO LOW PRES
CENTERED OVER THE NEB PANHANDLE BECOMES THE FOCUS FOR CONVECTIVE
ACTIVITY THROUGHOUT MUCH OF THE DAY WITH STRONG THETA-E ADVECTION
AHEAD OF IT. WARM ADVECTION COMBINED WITH DAYTIME HEATING SHOULD
PRODUCE QUITE UNSTABLE AIRMASS ACROSS MUCH OF FORECAST AREA AHEAD OF
ABOVE MENTIONED BOUNDARY TO GIVE MUCH OF FORECAST AREA A LIKELY
CHANCE AT STORMS THROUGHOUT THE DAY AND INTO THE NIGHT TIME. PW
VALUES FORECAST ABOVE 1.50 SO WITH MOST 3 HOUR FLASH FLOOD GUIDANCE
VALUES BELOW THIS FIGURE...FEEL COMFORTABLE CONTINUING FLOOD WATCH
CURRENTLY IN PLACE THROUGH NOON WEDNESDAY. WILL SHIFT BEGINNING TIME
BACK TILL 4PM HOWEVER BASED ON LACK OF EXTENT OF CONVECTION OVER
NORTHEAST NEBRASKA. MODELS CONTINUE TO MOVE FRONT THRU
SLOWER...LAGGING IT INTO THE EVENING ON WEDNESDAY. WL LET DAY CREW
ASSESS SITUATION FOR A POSSIBLE EXTENSION ON WATCH INTO WED EVENING.
NO MAJOR ADJUSTMENTS TO REMAINDER OF FORECAST AS UPPER TROF SWINGS
THRU THE NRN PLAINS AND KEEPS TEMPS COOLER.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...FLOOD WATCH 4PM TO NOON WEDNESDAY.
IA...FLOOD WATCH 4PM TO NOON WEDNESDAY.

&&

GRIFFIS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1126 AM CDT TUE JUN 15 2004

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-152300-
ANTELOPE-BOONE-BURT-BUTLER-CASS-CEDAR-COLFAX-CUMING-DODGE-DOUGLAS-
FREMONT IA-GAGE-HARRISON IA-JEFFERSON-JOHNSON-KNOX-LANCASTER-MADISON-
MILLS IA-MONONA IA-MONTGOMERY IA-NEMAHA-OTOE-PAGE IA-PAWNEE-PIERCE-
PLATTE-POTTAWATTAMIE IA-RICHARDSON-SALINE-SARPY-SAUNDERS-SEWARD-
SHELBY IA-STANTON-THURSTON-WASHINGTON-WAYNE-
1126 AM CDT TUE JUN 15 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN NEBRASKA AND SOUTHWEST
IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A CHANCE FOR ADDITIONAL THUNDERSTORMS ACROSS THE OUTLOOK
AREA THIS AFTERNOON AND EVENING. THE MAIN HAZARDS APPEAR TO BE LARGE
HAIL AND DAMAGING WINDS. A VERY MOIST AND UNSTABLE AIR MASS WILL BE
IN PLACE DURING THE AFTERNOON HOURS AS A COLD FRONT...MOVING
SOUTHEAST THROUGH THE DAKOTAS...APPROACHES THE OUTLOOK AREA. THIS
FRONT WILL BE THE PRIMARY FOCUS FOR THUNDERSTORM DEVELOPMENT THIS
AFTERNOON AND TONIGHT OVER EASTERN NEBRASKA AND SOUTHWEST IOWA.

ALSO...THE COMBINATION OF SATURATED GROUND AND SLOW MOVEMENT OF
STORMS WILL ENHANCE THE PROBABILITY OF FLASH FLOODING ACROSS THE
OUTLOOK AREA. THEREFORE...FLOOD WATCHES WILL REMAIN IN EFFECT FOR
EASTERN NEBRASKA AND SOUTHWEST IOWA THROUGH WEDNESDAY AFTERNOON.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SEVERE STORMS ARE POSSIBLE WEDNESDAY ACROSS SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA. FLASH FLOODING IS ALSO POSSIBLE THROUGH WEDNESDAY.

THERE IS A CHANCE OF THUNDERSTORMS ACROSS SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA WEDNESDAY AND FRIDAY.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION WILL PROBABLY BE REQUIRED THIS AFTERNOON
AND TONIGHT.

DEE