Flash Flooding in Nebraska, July 29, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1218 AM CDT SUN JUL 29 2007

.AVIATION...MAIN CONCERN WILL BE LOW CLOUDS LATE TONIGHT AND EARLY
MORNING. CURRENTLY THERE IS AN AREA OF SHOWERS ACROSS THE KGRI
TERMINAL AND THESE SHOULD CONTINUE A COUPLE OF HOURS OR SO. ONCE
THE PRECIPITATION ENDS EXPECT THAT SOME LOWER CLOUDS WILL FORM AND
GIVE IFR TO LIFR CEILINGS. ONCE THE SUN COMES UP EXPECT THAT THE
CEILINGS WILL LIFT AND BY AFTERNOON BE VFR AGAIN.

&&

.PREV DISCUSSION... /ISSUED 305 PM CDT SAT JUL 28 2007/

SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.  FOCUS REMAINS ON
CONVECTION THROUGH THE PERIOD.  REMNANT SHOWER ACTIVITY ASSOCIATED
WITH AN MCV AROSS WEST CENTRAL NEBRASKA HAS PERSISTED INTO THE
AFTERNOON ACROSS PORTIONS OF OUR CWA.  MEANWHILE...FARTHER SOUTH
INTO KANSAS INCREASED INSOLATION AND UPSLOPE FLOW SHOULD FOCUS YET
ANOTHER ROUND OF CONVECTION FOR THE LATE AFTERNOON AND EVENING HOURS
ACROSS THE HIGH PLAINS AND ALONG THE FRONTAL ZONE IN CENTRAL
KANSAS.  MODELS FORECAST UNSTABLE LAYER CAPES AROUND 2000 J/KG ON
THE PERIPHERY OF OUR SOUTHERN KANSAS COUNTIES THIS EVENING ACCORDING
TO THE NAM...WHEREAS THE RUC INDICATES THE INSTABILITY AXIS MORE SO
ACROSS OUR SOUTHERN KS COUNTIES.  BRUNT OF ACTIVITY HOWEVER WILL
OCCUR ONCE STORMS TO THE WEST ORGANIZE AND THEN GRADUALLY PROGRESS
EAST SOUTHEAST ACROSS SOUTHERN NEBRASKA AND KANSAS OVERNIGHT AND
SUNDAY MORNING.  THE MAIN HAZARD FROM THE STORMS WILL AGAIN BE THE
POTENTIAL FOR HEAVY RAINFALL WITH PRECIPITABLE WATER VALUES
AVERAGING NEAR TWO INCHES AND STORM MOTION PROGS AT JUST 5 KTS.  THE
PCPN WILL LINGER INTO SUNDAY...AGAIN IN THE SOUTHERN PORTION OF OUR
CWA AS UPPER RIDGING ACROSS THE NORTH SHUNTS THE ACTIVITY FARTHER
SOUTH WITH TIME.  TEMPERATURES ON SUNDAY WILL BE DEPENDENT UPON
ENDING TIME OF PCPN AND THE AMOUNT OF INSOLATION.  OVERALL READINGS
WILL BE NEAR TO BELOW NORMAL...WITH THE WARMEST TEMPERATURES ACROSS
THE NORTH.  WHETHER OR NOT ANY PCPN LINGERS OR REDEVELOPS SUNDAY
NIGHT WILL BE DEPENDENT ON WHAT HAPPENS TONIGHT AND HAVE KEPT SOME
LOW POPS FOR NOW.

LONG TERM...MONDAY THROUGH SATURDAY.  FORECAST CONCERN THE LAST FEW
DAYS HAS BEEN CENTERED ON HOW AN UPPER LEVEL LOW WILL IMPACT THE
AREA AT THE START OF THIS UPCOMING WEEK. THERE WAS SOME QUESTION AS
TO HOW WELL THE MODELS WERE HANDLING THE UPPER LOW AND ASSOCIATED
PRECIPITATION IN THE MONDAY THROUGH WEDNESDAY TIME PERIOD.
HOWEVER...IT IS NOW BECOMING MORE EVIDENT BASED ON CONSISTENT
OPERATIONAL AND ENSEMBLE FORECASTS THAT THE UPPER SYSTEM WILL
SLOWLY MEANDER ACROSS OUR CWA RESULTING IN ADDITIONAL CHANCES OF
SHOWERS AND THUNDERSTORMS MONDAY THROUGH WEDNESDAY. THIS WILL ALSO
RESULT IN MORE CLOUD COVER AND SLIGHTLY COOLER TEMPERATURES.
THEREFORE...HAVE INCREASED PRECIPITATION CHANCES AND CLOUD
COVER...WHILE LOWERING TEMPERATURES BY A FEW DEGREES TO GO WITH
HIGHS MORE IN THE UPPER 80S RATHER THAN LOWER 90S. FORECAST
ENSEMBLES SHOW THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS DURING
THE AFTERNOONS IN ASSOCIATION WITH DAYTIME HEATING BENEATH THE UPPER
WAVE.

PATTERN BECOMES MORE COMPLEX BY THURSDAY INTO NEXT WEEKEND WITH
LOWER CONFIDENCE DURING THIS PERIOD. UPPER LOW SHOULD HAVE WEAKENED
AND MOVED FAR ENOUGH AWAY FROM OUR AREA TO END PRECIPITATION CHANCES
ALTHOUGH A WEAK SFC FRONT IN THE AREA MAY NEED TO BE WATCHED FOR
POSSIBLE CONVECTION. OVERALL...TEMPERATURES SHOULD WARM BACK TO
AROUND 90 AND WILL CONTINUE TO GO WITH DRY WEATHER FROM THURSDAY
THROUGH THE END OF THE PERIOD.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HASTINGS NE
850 PM CDT SAT JUL 28 2007

NEZ039>041-046>049-060>064-072>077-082>087-291200-
VALLEY-GREELEY-NANCE-SHERMAN-HOWARD-MERRICK-POLK-DAWSON-BUFFALO-
HALL-HAMILTON-YORK-GOSPER-PHELPS-KEARNEY-ADAMS-CLAY-FILLMORE-
FURNAS-HARLAN-FRANKLIN-WEBSTER-NUCKOLLS-THAYER-
850 PM CDT SAT JUL 28 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
NEBRASKA.

.DAY ONE...TONIGHT.

THUNDERSTORMS TONIGHT WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL OF
AROUND 2 INCHES.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

INTERMITTENT CHANCES FOR THUNDERSTORMS EXIST SUNDAY THROUGH
WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT RAINFALL TOTALS.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE:
   HTTP://WWW.WEATHER.GOV/HASTINGS  (ALL LOWERCASE)

KSZ005>007-017>019-291200-
PHILLIPS-SMITH-JEWELL-ROOKS-OSBORNE-MITCHELL-
850 PM CDT SAT JUL 28 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
KANSAS.

.DAY ONE...TONIGHT.

HEAVY RAINFALL IS EXPECTED ACROSS PORTIONS OF THE OUTLOOK AREA
TONIGHT DUE TO SLOW MOVING THUNDERSTORMS.  RAINFALL AMOUNTS OF 2 TO
4 INCHES ARE LIKELY...WITH ISOLATED HIGHER AMOUNTS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

INTERMITTENT CHANCES FOR THUNDERSTORMS EXIST SUNDAY THROUGH
WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT RAINFALL TOTALS.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE:
   HTTP://WWW.WEATHER.GOV/HASTINGS  (ALL LOWERCASE)