Severe Thunderstorm Warning 13, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA NE
246 PM CDT THU APR 5 2001

MAIN FCST CHALLENGE IS TSRA THREAT AND TEMPS THRU THE PD.  WEAK
SHRTWV WHICH GENERATED CLUSTER OF SVR TSRA DURG THE LATE MORNING
AND EARLY AFTN HRS CONTINUES TO MOVE EAST INTO SW MN AND NW IA
ATTM.  THIS SHRTWV IS PUSHING THE FNTL BNDRY FURTHER SE THAN WHAT
THE MODELS INDICATED YESTERDAY.  18Z SFC ANLYS INDICATES FRONT FROM
NEAR FOD TO FNB TO RSL.  THE MDLS ARE FAIRLY CONSISTENT IN SHOVING
THE FRONT FURTHER SE INTO CNTRL KS AND NRN MO EARLY TNGT BEFORE
BECOMING STNRY.  THIS WILL ALSO SHIFT THE FOCUS FOR CONVECTIVE
DEVELOPMENT EARLY TNGT S OF THE CWA.

LATER TNGT HOWEVER...AS LOW LVL JET REINTENSIFIES OVER THE CNTRL AND
SRN PLNS...ISENTROPIC LIFT OF HIGH THETA-E AIR OVER THE FNTL BNDRY
WILL LIKELY GENERATE REDEVELOPMENT OVER THE CWA...SPCLY OVER THE E
CNTRL AND SE SECTIONS.  AGAIN MAIN THREAT WITH THIS ACTIVITY WILL BE
LRG HAIL WITH LOW WBZ HGTS.

ON FRI...TNGTS ACTIVITY WILL LIKELY STILL BE ONGOING DURING THE
EARLY MORNING HRS...BUT WILL END BY MID-LATE MORNING AS VERTICAL
MOTION FIELDS SHIFT EAST.  THE MDLS PROG THE SFC LOW TO DEEPEN
RAPIDLY LATE IN THE DAY OVER THE WRN HIGH PLNS.  TSRA REDEVELOPMENT
WILL LIKELY TAKE PLACE INITIALLY ALG WELL ESTABLISHED DRYLINE OVER
THE SRN HIGH PLNS AS HGT FALLS ASSD WITH MAIN UPPER LEVEL BEGIN TO
OVERSPREAD THE AREA.  ACTIVITY WILL THEN MOVE/DEVELOP RPDLY NEWD
INTO THE CNTRL NE/KS DURG THE LATE AFTN...AND INTO ERN SECTIONS OF
BOTH STATES DURING THE LATE AFTN/EARLY EVE HRS.  THE MAIN SYSTEM
WILL LIKELY DRIVE WARM FRONT N INTO THE CWA DURG THE DAY.  QUESTION
IS HOW FAR N.  THIS WILL BE A FUNCTION OF HOW MUCH AND HOW EXTENSIVE
CONVECTION IS TNGT AS THIS WILL SHARPEN AND REINFORCE FRONTAL
BOUNDARY OVER SE NEB/NE KS EARLY IN THE DAY.  NEVERTHELESS...THERE
WILL BE A STRONG TEMP GRADIENT FROM N TO S ACROSS THE CWA.  WILL
RANGE FROM THE MID 60S FAR N...TO THE UPPER 70S FAR SE.

FRI NIGHT...MAIN ACTIVITY FOR OUR CWA WILL LIKELY RANGE FROM ABOUT
5PM-11PM AS BEST HGHT FALLS...VERITICAL MOTION FIELDS...AND LIFT
MOVES ACROSS THE CWA.  WILL GO WITH TSRA LIKELY ALL AREAS.  WILL
RESTRICT FAR NW AREA TO MAINLY BEFORE MIDNIGHT.  GRADIENT INCREASES
BEHIND EJECTING SFC LOW SO WNDS WILL SHIFT TO WNW LATE OVER THE AREA
AND BECOME WINDY NW AREAS.

SAT...EJECTING SFC LOW WILL CONT TO MOVE NE INTO THE UPPER MDWST.
SUBSIDENCE WILL BE PREVALENT ACROSS THE AREA WITH GUSTY WNW
WNDS...SPCLY THRU EARLY AFTN HRS.  WILL GO WITH PTLY SUNY SKIES AND
HIGHS RANGING FROM THE LOWER 50S FAR NE TO LOWER 60S FAR SE.

SAT NIGHT...GRADIENT CONTS TO DEC.  SOME MID LVL WAA CLDS INDICATED
SO WL GO PTLY CLDY.

IN THE EXTENDED...SW UPPER FLOW WILL BE MAINTAINED AT LEAST FOR THE
NEXT 7 DAYS AS NEXT IN A SERIES OF UPPER LOWS DROPS S INTO THE WRN
U.S. BEHIND FRIDAYS EJECTING UPPER LOW.  AFTER DRY/MILD DAYvS SUN
THRU TUES...NEXT THREAT OF SHRA/TSRA RETURNS FOR THE MID PART OF
NEXT WEEK AS THIS SYSTEM BEGINS TO MOVE NE.

.OMA...NONE

SKERRITT