Severe Thunderstorm Warning 270, NWS Hastings, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
310 PM CDT WED AUG 17 2005

.DISCUSSION...MAIN PROBLEMS SURROUND THUNDERSTORM/SEVERE WEATHER
CHANCES TONIGHT.  FIRST ROUND OF CONVECTION HAS ALL BUT EXITED THE
FORECAST AREA.  THIS AREA WAS DRIVEN BY STRONG H85 THETA-E ADVECTION
WHICH CONTINUES TO PERSIST IN THE EASTERN PORTIONS OF THE FORECAST
AREA.  THE MAIN WEATHER MAKER FOR TONIGHT WILL BE AN UPPER LEVEL
TROUGH CURRENTLY MOVING ACROSS THE DAKOTAS INTO WESTERN NEBRASKA.
THE BULK OF THE UPPER LEVEL FORCING WITH THIS IS EXPECTED TO GRAZE
THE NORTHERN PORTIONS OF THE FORECAST AREA.  THE LEFT EXIT REGION OF
THE UPPER LEVEL JET WILL ALSO BRING ENHANCED UPPER LEVEL DIVERGENCE
TO NORTHERN PARTS OF NEBRASKA THIS EVENING.  IN THE LOW LEVELS...A
SURFACE TROUGH IS CURRENTLY LOCATED FROM CENTRAL SOUTH DAKOTA INTO
THE NEBRASKA PANHANDLE.  A FEW CUMULUS CLOUDS HAVE STARTED TO
DEVELOP IN ADVANCE OF THE TROUGH...HOWEVER THE 18Z LBF SOUNDING
SHOWS THAT THERE IS STILL A CAP IN PLACE THAT WILL HAVE TO BE
OVERCOME.  HAVE DECIDED TO LEAVE IN THE HIGHEST POPS ACROSS THE
NORTH CLOSER TO THE UPPER LEVEL FORCING...HOWEVER FURTHER SOUTH WILL
TAPER OFF TO LOWER CHANCES.  THE SEVERE WEATHER POTENTIAL IS
STILL THERE WITH A GOOD INSTABILITY AXIS OF SBCAPES OF 1500-3000
J/KG AND DEEP LAYER SHEAR OF 35-40 KTS...BUT RELATIVELY WEAK 0-1 KM
SHEAR COULD LIMIT THE TORNADO POTENTIAL.

THE ENTIRE SYSTEM MOVES ACROSS RAPIDLY TONIGHT LEAVING A MAINLY DRY
DAY ON THURSDAY.  IT WILL BE HOT TOMORROW WITH H85 TEMPERATURES IN
THE MIDDLE 20S CELSIUS...HOWEVER WOULD LIKE TO SEE STRONGER LOW
LEVEL FLOW TO AIDE IN THE MIXING POTENTIAL.  WILL KEEP THE SMALL
CHANCE OF THUNDERSTORMS THURSDAY NIGHT WITH ANOTHER ROUND OF H85
WAA/THETA-E ADVECTION...BUT THE LOW LEVEL JET IS LATE TO ARRIVE
AND NOT VERY STRONG WHICH WILL PROBABLY LIMIT THE CHANCES OF
THUNDERSTORMS.

.LONG TERM...12Z FRIDAY THROUGH NEXT WEDNESDAY.  PRIMARY FORECAST
CONCERN IN THE EXTENDED PERIOD WILL CENTER AROUND THUNDERSTORM
CHANCES ON FRIDAY AND FRIDAY NIGHT.

AN AREA OF SFC LOW PRESSURE WILL DEEPEN ACROSS SOUTH CENTRAL
NEBRASKA AND NORTH CENTRAL KANSAS DURING THE DAY ON FRIDAY.  A COLD
FRONT WILL SLOWLY SLIDE SOUTHEAST THROUGH NEBRASKA AND INTO NORTHERN
KANSAS BY FRIDAY NIGHT.  THUNDERSTORMS SHOULD DEVELOP ALONG AND
BEHIND THE COLD FRONTAL BOUNDARY WITH MORE OF A CAPPED ATMOSPHERE
LIMITING CONVECTION OUT AHEAD OF THE FRONT.  BEST UPPER LEVEL
SUPPORT WILL AGAIN BE NORTH OF THE AREA IN ASSOCIATION WITH A 500 MB
VORT MAX TRACKING ACROSS THE US/CANADIAN BOARDER.  THE GFS AND NAM
HAVE BEEN CONSISTENT FOR THE LAST SEVERAL DAYS INDICATING THIS
OVERALL SET UP.  THEREFORE BUMPED POPS UP TO AROUND 40 PERCENT
ACROSS SOUTHERN AND EASTERN PORTIONS OF OUR CWA WHERE CONVECTION
SEEMS MOST LIKELY.

COLD FRONT SLIDES FAR ENOUGH SOUTH BY EARLY SATURDAY MORNING TO END
ALL PRECIPITATION ACROSS OUR CWA.  A RELATIVELY COOL AREA OF HIGH
PRESSURE BUILDS INTO OUR REGION RESULTING IN COMFORTABLE WEEKEND
TEMPERATURES WITH HIGHS AROUND 80 DEGREES.

THE REGION SHOULD REMAIN DRY UNTIL SOMETIME LATE TUESDAY OR
WEDNESDAY WHEN THE NEXT SHORT WAVE TRACKS EASTWARD ACROSS THE
NORTHERN PLAINS.  GFS AND ECMWF BOTH PICK UP ON THE DIGGING TROUGH
BUT THERE ARE STILL THE QUESTIONS OF TIMING AND TROUGH DEPTH.  FOR
NOW..HAVE INTRODUCED SLIGHT POPS IN THE TUESDAY NIGHT TIME FRAME AND
WILL HAVE TO MONITOR THIS SYSTEM FOR THE NEXT FEW DAYS.

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

&&

KING/WESELY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HASTINGS NE
1140 AM CDT WED AUG 17 2005

KSZ005-006-017-018-NEZ039-040-046-047-060>062-072>075-082>085-
181200-
PHILLIPS-SMITH-ROOKS-OSBORNE-VALLEY-GREELEY-SHERMAN-HOWARD-DAWSON-
BUFFALO-HALL-GOSPER-PHELPS-KEARNEY-ADAMS-FURNAS-HARLAN-FRANKLIN-
WEBSTER-
1140 AM CDT WED AUG 17 2005

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON OR EVENING
ACROSS THE AREA. THE MAIN THREATS ARE EXPECTED TO BE HAIL UP TO
THE SIZE OF GOLF BALLS AND WINDS IN EXCESS OF 60 MPH. ISOLATED
TORNADOES ARE ALSO POSSIBLE...MAINLY BEFORE 10 PM.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CHANCE OF THUNDERSTORMS THURSDAY NIGHT THROUGH FRIDAY
NIGHT. IT APPEARS THAT SOME OF THE STORMS FRIDAY AFTERNOON AND
EVENING MAY BECOME SEVERE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON AND EVENING.

&&

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

KSZ007-019-NEZ041-048-049-063-064-076-077-086-087-181200-
JEWELL-MITCHELL-NANCE-MERRICK-POLK-HAMILTON-YORK-CLAY-FILLMORE-
NUCKOLLS-THAYER-
1140 AM CDT WED AUG 17 2005

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

ANY LINGERING THUNDERSTORMS WILL END EARLY THIS
AFTERNOON...HOWEVER MORE THUNDERSTORMS ARE POSSIBLE TONIGHT. SOME
OF THE THUNDERSTORMS TONIGHT COULD BE SEVERE WITH LARGE HAIL UP TO
THE SIZE OF QUARTERS AND WINDS GUSTS IN EXCESS OF 60 MPH.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CHANCE OF THUNDERSTORMS THURSDAY NIGHT THROUGH FRIDAY
NIGHT. IT APPEARS THAT SOME OF THE STORMS FRIDAY AFTERNOON AND
EVENING MAY BECOME SEVERE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT

&&

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

KING

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HASTINGS NE
914 PM CDT WED AUG 17 2005

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

0845 PM     HAIL             7 S COZAD               40.76N 99.99W
08/17/2005  1.75 INCH        DAWSON             NE   LAW ENFORCEMENT

&&

CARMEL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HASTINGS NE
929 PM CDT WED AUG 17 2005

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

0923 PM     TSTM WND GST     JOHNSON LAKE            40.68N 99.85W
08/17/2005  60 MPH           GOSPER             NE   LAW ENFORCEMENT

            LARGE TREE BRANCHES DOWN ON NORTH SIDE OF JOHNSON LAKE.

&&

CARMEL