Severe Thunderstorm Warning 261, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
310 PM CDT SAT AUG 9 2003

THE MAIN FORECAST CONCERN CONTINUES TO BE PRECIP CHANCES THE
REMAINDER OF WEEKEND AND MAX TEMPS FOR SUN AND MON.

19Z SURFACE ANALYSIS SHOWS DEEPENING LOW PRESSURE IN CENTRAL SOUTH
DAKOTA...WHICH IS SLOWLY MOVING TO THE EAST.  LATEST VISIBLE
SATELLITE IMAGERY SHOWS AN AREA OF THUNDERSTORMS AND SHOWERS ACROSS
CENTRAL SOUTH DAKOTA INTO SOUTHEASTERN NORTH DAKOTA.  12Z UPPER AIR
ANALYSIS SHOWS 700 AND 850 MB MOISTURE AXIS EXTENDING FROM NORTH
DAKOTA THROUGH NEBRASKA AND KANSAS.  700 MB WINDS AND HEIGHTS AS
WELL AS 500 MB ANALYSIS DISPLAYS THE APPROACHING SHORTWAVE...
CURRENTLY IN CENTRAL AND WESTERN SOUTH DAKOTA.

FIRST PRECIPITATION CHANCES APPEAR TO COME LATER THIS EVENING WITH
THE POSSIBILITY OF THE CURRENT PRECIP IN CENTRAL SOUTH DAKOTA AND
NORTHWEST NEBRASKA MOVING INTO OUR AREA. 18Z ETA SHOWING THE PRECIP
MOVING JUST TO OUR WEST.  IT APPEARS THE BEST CHANCES ACROSS THE
CENTRAL AND NORTHWESTERN CWA SHOULD COME DURING THE EARLY MORNING
SUNDAY HOURS.  ALL OF THE MODELS ARE CONSISTENT IN DEVELOPING AN
MCS...THE PROBLEMS ORIGINATE WITH THE TRACK OF THE SYSTEM.  GFS HAS
THE PRECIP BEGINNING IN THE NORTHERN PARTS OF CWA AROUND 12
AM...WHILE THE ETA TAKES UNTIL 3AM.  MODELS INDICATE WEAKENING IN
THE SYSTEM DURING THE MORNING HOURS SUNDAY...BUT SHOULD PICK UP ONCE
AGAIN ACROSS THE CWA ON SUNDAY AFTERNOON AND EVENING.  HAVE MAINLY
PLACED 30 POPS ACROSS THE AREA...WITH UNCERTAINTY IN THE EXACT TRACK
AND LOCATION OF DEVELOPMENT OF THIS CONVECTION AND PRECIPITATION.
BASICALLY KEPT THE PREVIOUS SHORT TERM PRECIPITATION CHANCES...WITH
SOME MINOR TIMING ADJUSTMENTS.  CURRENT RUN OF THE GFS KEEPS PRECIP
CHANCES ACROSS THE CWA ON MONDAY...HOWEVER...HAVE IGNORED THIS
FEATURE AND DRIED OUT THE AREA ON MONDAY.

MAXIMUM TEMPERATURES ARE ALSO A CONCERN FOR THE NEXT TWO DAYS.  HAVE
DROPPED TEMPERATURES ON SUNDAY ABOUT 5 DEGREES IN THE NORTH...WITH
LOWER 90S IN THE SOUTH.  WITH CLOUDS AND PRECIPITATION PRESENT THIS
SEEMED REASONABLE AND FIT IN WITH SURROUNDING OFFICES.  DID NOT
ADJUST EXTENDED TEMPERATURES MORE THAN ONE OR TWO DEGREES.

IN THE EXTENDED PERIODS...IT LOOKS LIKE IT SHOULD REMAIN DRY WITH
SOME WARMING TRENDS.  MODELS CONTINUE TO SHOW A BROADENING RIDGE
WITH SOME 590 HEIGHT LINES OVER THE CWA...SHOWING THE POSSIBILITY OF
HOTTER TEMPERATURES.

PREVIOUS MODEL RUNS AT 00Z DISPLAYED A LOW PRESSURE SYSTEM MOVING
EAST AND THEN NORTH INTO CWA IN THE DAY 7 RANGE...WITH RIDGE MOVING
TO THE GREAT LAKES AND EASTERN SEABOARD REGION.  HOWEVER...06Z MODEL
RUN OF GFS REVERTED BACK TO PREVIOUS SOLUTION OF BROADENING RIDGE
AND NO CLOSED LOW.  THEREFORE...HAVE REMOVED CHANCE OF PRECIP ON DAY
7.

OMA...NONE.

CAMPBELL

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-101030-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
500 PM CDT SAT AUG 9 2003

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

.DAY ONE...TONIGHT AND SUNDAY

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE AREA TONIGHT INTO
SUNDAY. STRONG TO SEVERE THUNDERSTORMS EXTEND FROM NORTH CENTRAL
NEBRASKA INTO EASTERN SOUTH DAKOTA LATE THIS AFTERNOON AND COULD
MOVE INTO PARTS OF EASTERN NEBRASKA AND WEST CENTRAL IOWA LATER
TONIGHT. ISOLATED SEVERE THUNDERSTORMS PRODUCING DAMAGING WINDS
AND LARGE HAIL ARE POSSIBLE LATER THIS EVENING...MAINLY NORTHWEST
OF A COLUMBUS TO ONAWA IOWA LINE. THUNDERSTORMS MAY CONTINUE TO
TRACK SOUTH ACROSS THE REMAINDER OF EASTERN NEBRASKA AND
SOUTHWEST IOWA AFTER MIDNIGHT...BUT ARE NOT EXPECTED TO BE SEVERE
AS THEY MOVE AWAY FROM THE BETTER MOISTURE AND INSTABILITY. THERE
WILL BE A CHANCE OF MORE THUNDERSTORMS DEVELOPING ACROSS THE AREA
SUNDAY AFTERNOON WITH SOME SEVERE STORMS POSSIBLE.

.DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH SATURDAY

THE CHANCE OF THUNDERSTORMS WILL CONTINUE INTO SUNDAY NIGHT. A
WEAK COLD FRONT...COMBINED WITH AN UPPER LEVEL DISTURBANCE AND
SOMEWHAT GREATER WIND SHEAR...MAY ALLOW A FEW OF THESE STORMS TO
BECOME SEVERE DURING THE EVENING. LARGE HAIL AND DAMAGING WINDS
WILL BE THE MAIN HAZARDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED OVER PARTS OF NORTHEAST NEBRASKA
TONIGHT AND IN EASTERN NEBRASKA AND SOUTHWEST IOWA SUNDAY
AFTERNOON AND EVENING.

FOBERT