Severe Thunderstorm Warning 128, NWS Hastings, NE

SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
325 PM CDT TUE JUN 17 2003

PRECIP CHANCES TONIGHT AND TOMORROW MAIN CHALLENGE FOR THIS FORECAST.

LATEST VISIBLE SAT IMAGERY FROM THIS AFTERNOON SHOWS TWO MCVS
ACROSS REGION WITH ONE OVER NORTHWEST KANSAS AND THE OTHER OVER
WESTERN NEBRASKA.  ALOFT UPPER RIDGE REMAINS ANCHORED ACROSS THE
WESTERN CONUS WITH STRONGER JET WINDS WELL REMOVED FROM AREA AND
RESULTANT DEEP LAYER SHEAR VERY WEAK.  AT THE SURFACE A VERY
DISORGANIZED PATTERN EXISTS WITH NUMEROUS TROUGHS AND OUTFLOW
BOUNDARIES ALTHOUGH ONE MAIN OUTFLOW CAN BE SEEN FROM EASTERN
NEBRASKA INTO NW KANSAS AND THE OTHER TROUGH OVER NORTHERN
NEBRASKA.  RADAR MOSAIC FROM THE REGION ALREADY SHOWS CONVECTION
ALREADY PRESENT ALONG SOUTHERN OUTFLOW BOUNDARY WITH CONVECTION
BEGINNING TO FORM FURTHER NORTH AS WELL.  NONE OF THE MODELS APPEAR
TO HAVE CAUGHT MCVS OR EXACT LOCATION OF OUTFLOW BOUNDARIES SO WILL
ATTEMPT TO WING IT FOR TONIGHT WITH A BLEND BEYOND.

ANTICIPATE CONVECTION TO EXPAND IN COVERAGE FROM SOUTHWEST TO
NORTHEAST ACROSS FORECAST AREA BY THIS EVENING AS MAIN TROUGH ENTERS
THIS AREA. CONVECTIVE TEMPS WILL REMAIN LOW AND WITH PRESENCE OF
OUTFLOW BOUNDARIES TO FIRE MORE CONVECTION FEEL LIKELY POPS ARE
WARRANTED OVER THIS AREA AS WELL.  WITH LITTLE TO NO SHEAR EXPECT
CONVECTION TO BE DOMINATED BY OUTFLOW BOUNDARIES.  GIVEN THIS
SETUP... COLD POOL UNDER MAIN BELT OF CONVECTION SHOULD PUSH TROUGH
FURTHER SOUTH INTO NORTH CENTRAL KANSAS BY EARLY MORNING.  THIS WILL
ACCORDINGLY PUSH BEST CHANCE OF PRECIP SOUTH AS WELL.

EXPECT SOME CONVECTION TO LINGER INTO THE MORNING HOURS ON WEDNESDAY
ACROSS SOUTHERN HALF OF FORECAST AREA BUT NORTHERN COUNTIES SHOULD
BEGIN TO DRY OUT BY NOON.  DAILY CYCLE OF CONVECTION THEN STARTS
OVER AGAIN BY AFTERNOON WEDNESDAY ALTHOUGH IT SHOULD REMAIN MOSTLY
ACROSS NORTH CENTRAL KANSAS COUNTIES WITH MOST OF SOUTH CENTRAL
NEBRASKA DRY.  CLOUD COVER WILL MAKE HIGH TEMPS TRICKY BUT WILL AIM
CLOSE TO MET VALUES.

PRECIP THREAT SHOULD DIMINISH FAIRLY QUICK BY MID EVENING ON
WEDNESDAY AS OUTFLOW DURING THE AFTERNOON PUSHES AFORE MENTIONED
TROUGH AND ASSOCIATED CONVECTION SOUTH OF AREA.

MODELS THEN ATTEMPT TO ADVERTISE THAT SURFACE HIGH WILL RIDGE INTO
AREA ON THURSDAY WITH BEST MOISTURE/INSTABILITY BEING FUNNELED INTO
THE HIGH PLAINS.  THIS SHOULD LEAVE MOST OF AREA DRY ALTHOUGH THERE
IS SOME THREAT OF CONVECTION MAKING IT INTO WESTERN HALF OF AREA
DURING THE EVENING.  HOWEVER...WILL LEAVE FORECAST DRY FOR NOW UNTIL
TIMING OF BOUNDARIES/TROUGH CAN BE BETTER RESOLVED.

FRIDAY THROUGH TUESDAY...AS USUAL MEDIUM RANGE MODELS START OFF IN
DECENT AGREEMENT ON BUILDING UPPER RIDGE OVER REGION FRIDAY.
HOWEVER... THEY DIVERGE QUICKLY AFTER THAT WITH RESPECT TO
STRENGTH/TIMING OF MOVING WEST COAST TROUGH INTO REGION.  ENSEMBLES
TEND TO INDICATE ECMWF IS TOO QUICK AT PUSHING WAVE OUT OF WESTERN
CONUS AND WILL AIM CLOSER TO SLOWER GFS FOR THIS TIME PERIOD.  THIS
LOOKS TO EQUATE TO TEMPS IN THE 80S AND 90S WITH GENERALLY A SLIGHT
CHANCE OF PRECIP AT BEST.

.GID...NONE.

AWJ

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-181200-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HASTINGS NE
413 PM CDT TUE JUN 17 2003

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BECOME MORE
WIDESPREAD ACROSS SOUTH CENTRAL NEBRASKA THE REST OF THIS AFTERNOON
AND EVENING.

THIS ACTIVITY IS ASSOCIATED WITH A WEAK FRONT DROPPING
SOUTH THROUGH NEBRASKA TOWARD KANSAS...WITH ADDITIONAL STORM
DEVELOPMENT OCCURRING ALONG OUTFLOW BOUNDARIES FROM MONDAYS
THUNDERSTORMS.

WEAK WIND FIELDS ALOFT WILL LIMIT ANY SEVERE WEATHER POTENTIAL FROM
THE STORMS...ALTHOUGH AN ISOLATED STRONG STORM WITH PENNY SIZE
HAIL IS POSSIBLE...THE MAIN HAZARD FROM THE STORMS WILL BE LOCALLY
HEAVY RAINFALL.  THE SLOW MOVING STORMS MAY PRODUCE 1 TO 2 INCHES OF
RAINFALL IN A SHORT AMOUNT OF TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS WILL LINGER NEAR THE DECAYING BOUNDARY ON WEDNESDAY...
BUT NO SEVERE WEATHER IS ANTICIPATED. ANOTHER ROUND OF THUNDERSTORMS
IS IN THE FORECAST FOR LATE SATURDAY THROUGH SUNDAY NIGHT...AS A COLD
FRONT MOVES ACROSS THE AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

T