Severe Thunderstorm Warning 32, NWS Hastings, NE

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HASTINGS NE
906 PM CDT WED MAY 12 2004

.DISCUSSION...RADAR MOSAIC FROM THIS EVENING SHOWS SCATTERED
CONVECTION OVER FAR SOUTHEAST CWA WITH MAIN PRECIP AREA STILL WEST
OF AREA AT THIS TIME.  DOES NOT LOOK AS THOUGH WIDESPREAD PRECIP
WILL MAKE INTO INTO AREA UNTIL AFTER MIDNIGHT. BASED OFF THIS
TREND...HAVE LOWERED PRECIP CHANCES FOR THIS EVENING BUT KEPT
OCCASIONAL PRECIP CHANCE IN FOR TONIGHT AS UPPER SYSTEM MOVES INTO
THE REGION.  NO OTHER CHANGES MADE TO THE FORECAST.
&&

.PREV DISCUSSION...SFC COLD FRONT HANGING UP FM SE NE INTO SC KS AS
LEAD UPR TROF ACCELERATES INTO CANADA. SECONDARY UPSTREAM TROF AND
JET STREAK BEGINNING TO PIVOT E ACRS NW CO ATTM W/RAPID PRES FALLS
NOTED OVR SE CO AS SFC WAVE DVLPS ALG THE FRONT THERE. OTHERWISE
STOUT LL THERMAL GRADIENT IN PLACE W/DEEP MSTR JUST S AND POISED TO
RTN OVERNIGHT. GIVEN OBSVD RAINFALL ACRS SE CWA LAST SVRL DAYS AND
FVRBL SETUP OVERNIGHT FOR TRAINING CONVN TO DVLP ALG STALLED 850MB
THETA GRADIENT...FEEL A NEED EXISTS FOR FLOOD WATCH THAT AREA ESP IN
LIGHT OF DEGREE OF FORCED ASCENT TONIGHT OVR DEEP FRONTAL ZONE AND
DEPTH OF MSTR TO WORK WITH AND FFG/S SURPRISINGLY LOW. LOOKS LIKE A
GOOD WIDESPREAD SOAKER AS LLJ RESPONDS TO INCREASING LARGE SCALE
ASCENT IN ASSOCN/W EJECTION OF UPR TROF AND RR OF JET MAX LIFTING
OUT ACRS SD. MSTR FLUX WITHIN 305K SFC VERY IMPRESSIVE AND W/ADVTN
OF GOOD EML CUTTING OUT ALG S END OF UPR SW THUNDER LOOKS GOOD
ROUGHLY SOUTH OF I-80 TONIGHT. RAINFALL COULD BE QUITE SUBSTANTIAL
IF IT WORKS OUT. OTHERWISE...SYS PULLS OUT FAIRLY QUICKLY ON THU W/
BULK OF PRECIP ENDING W-E BY LATE MORNING/EARLY AFTN. OTHERWISE
SECONDARY CAA SURGE REALLY GOING TO HAMMER TEMPS TOMORROW ESP
W/PRECIP AROUND AND WILL LIKELY BREAK ALL RECORD LOW HIGHS IF ETA
DEGREE OF COOLING IS INDEED CORRECT. THAT LEADS TO ANOTHER PROBLEM
COME FRI MORNING ESP W/SFC RIDGE OVERHEAD. PENDING TIMING ON DECAY
OF RESIDUAL CLOUDS AND SFC GRADIENT...COULD POTENTIALLY FREEZE ACRS
NW THIRD OR SO AND HAVE MENTIONED IN HWO AT THIS POINT. SOMETHING TO
PONDER FURTHER LATER BUT HARD TO SWALLOW GIVEN SOIL TEMP RESPONSE TO
WARM WX AS OF LATE. NW CWA SITTING IN UPPER 60S TO LOW 70S AVG SOIL
TEMPS AS OF YDA.

LONG TERM...FRIDAY AND BEYOND. PRECIPITATION EXPECTED TO COME TO AN
END BY LATE THURSDAY NIGHT AS MEAN UPPER TROF AXIS ADVANCES ONTO
PLAINS AND FINALLY KICKS BAROCLINIC ZONE EAST OF FORECAST AREA. WILL
SEE A DECENT TEMPERATURE RECOVERY GIVEN EWD PROGRESSION OF SFC
HIGH/SHALLOW COOL LAYER COUPLED W/ FAIR AMOUNT OF SUN AND ONSET OF
RETURN FLOW.

LEE TROF BECOMES FIRMLY ESTABLISHED BY SAT...AND GRADUAL TEMPERATURE
MODERATION EXPECTED TO CONTINUE. S/W TROF PROGGED TO PASS THROUGH
PLAINS EARLY SAT...AND COUPLED W/ 30-40KT LLJ/850MB WAA...MAY SEE
SOME SHOWERS COME CLOSE TO NRN ZONES. GIVEN ETA FORECAST SOUNDINGS
IN THIS AREA...BELIEVE THIS ACTIVITY WOULD BE VERY ELEVATED AND
RESULT IN MOSTLY VIRGA GIVEN RELATIVELY DRY SFC-700MB LAYER.
STRONGER S/W TROF PASSES ACRS NORTHERN PLAINS DURING THE
AFT/EVE...BUT ANY RESULTING QPF WILL BE WELL NORTH OF FORECAST AREA.

SUNDAY AND BEYOND A BIT MORE UNCERTAIN AS EVENTUAL EVOLUTION OF ERN
PAC RIDGE CONTINUES TO PLAGUE EXTENDED PERIODS...W/ EACH MODEL
OFFERING A DIFFERING SOLUTION. GFS CONTINUES TO BE OVERLY AGGRESSIVE
WITH RIDGE BREAKDOWN AND RESULTING S/W ENERGY IT SENDS THROUGH THE
PLAINS ON MONDAY...THOUGH 12Z RUN HAS TRENDED MORE TOWARD THE ECMWF
SOLUTION. FOR NOW...HAVE STUCK WITH THAT IDEA AND KEPT PRECIP
MENTION OUT WHILE BUMPING UP TEMPERATURES JUST A BIT THROUGH WED W/
ECMWF INDICATION OF LEE TROF AND WARMING 850MB TEMPS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...FLOOD WATCH CLAY...FILLMORE...WEBSTER...NUCKOLLS AND THAYER.
KS...FLOOD WATCH SMITH...JEWELL...OSBORNE...MITCHELL.

&&

AWJ/T/VII

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HASTINGS NE
741 PM CDT WED MAY 12 2004

KSZ006-007-018-019-NEZ076-077-085>087-131200-
CLAY-FILLMORE-JEWELL-MITCHELL-NUCKOLLS-OSBORNE-SMITH-THAYER-WEBSTER-
741 PM CDT WED MAY 12 2004

...A FLOOD WATCH IS IN EFFECT UNTIL 10 AM THURSDAY MORNING...

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

.DAY ONE...REST OF TONIGHT

A RISK OF FLASH FLOODING IS POSSIBLE TONIGHT EAST OF A LINE EXTENDING
FROM CLAY CENTER IN CLAY COUNTY NEBRASKA TO NATOMA IN OSBORNE
COUNTY KANSAS.

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE INTO THE
OUTLOOK AREA TONIGHT AS AN UPPER LEVEL DISTURBANCE PUSHES INTO THE
REGION.  HEAVY RAINFALL IN EXCESS OF TWO INCHES IN COMBINATION WITH A
WET GROUND FROM RAINFALL OVER THE LAST FEW DAYS...MAY CAUSE SOME
FLOODING OF AREA STREAMS AND CREAKS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH WEDNESDAY

AN UNSEASONABLY COLD AIR MASS WILL BE IN PLACE THURSDAY NIGHT...WITH
SOME POTENTIAL FOR SUB FREEZING TEMPERATURES NORTHWEST OF A YORK TO
PHILLIPSBURG LINE TOWARD DAYBREAK FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION SHOULD NOT BE NEED THE REST OF TONIGHT.

KSZ005-017-NEZ039>041-046>049-060>064-072>075-082>084-131200-
ADAMS-BUFFALO-DAWSON-FRANKLIN-FURNAS-GOSPER-GREELEY-HALL-HAMILTON-
HARLAN-HOWARD-KEARNEY-MERRICK-NANCE-PHELPS-PHILLIPS-POLK-ROOKS-
SHERMAN-VALLEY-YORK-
741 PM CDT WED MAY 12 2004

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

.DAY ONE...REST OF TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE INTO THE
OUTLOOK AREA TONIGHT AS AN UPPER LEVEL DISTURBANCE PUSHES INTO THE
REGION.  HEAVY RAINFALL FROM THESE STORMS MAY CAUSE SOME NUISANCE
FLOODING OF AREA STREAMS AND CREAKS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH WEDNESDAY

AN UNSEASONABLY COLD AIR MASS WILL BE IN PLACE THURSDAY NIGHT...WITH
SOME POTENTIAL FOR SUB FREEZING TEMPERATURES NORTHWEST OF A YORK TO
PHILLIPSBURG LINE TOWARD DAYBREAK FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION SHOULD NOT BE NEED THE REST OF TONIGHT.

AWJ