Severe Thunderstorm Warning 258, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
215 PM CDT SAT JUN 24 2006

.DISCUSSION...

THUNDERSTORM CHANCES INTO SUNDAY AND THEN AMOUNT OF POTENTIAL COOL
DOWN NEXT WEEK ARE APPARENT FORECAST CHALLENGES THIS FORECAST.

SHORT TERM...TONIGHT AND SUNDAY. 12Z UA ANALYSIS/STLT IMAGERY INTO
EARLY AFTERNOON INDICATED NWRLY UPPER FLOW WAS OCCURRING ACROSS MUCH
OF THE CENTRAL PLAINS SATURDAY MORNING WITH A WEAK WAVE MOVG FM
SERN NEBR INTO NERN KS/NWRN MO AND A STRONGER TROUGH WITH
UNSEASONABLY COOL TEMPERATURES AT 500 MB SPREADING FROM ND INTO
NRN SD AND MN. APPEARS BEST TSTMS CHANCES TONIGHT WILL EXIST OVR
FAR SERN ZONES EARLY THIS EVENING WHERE INITIAL
INSTABILITY/CONVERGENCE WAS SLIGHTLY BETTER...ALTHOUGH THIS MAY
SET UP JUST SE OF THE CWA BY 00Z...AND THEN OVER NERN ZONES AS
CONVECTION IN ASSOCIATION WITH NRN PLAINS TROUGH/CDFNT MOVES SEWD
AND DVLPS SW INTO SECOND INSTABILITY AXIS. IN ADDITION...SINCE 18Z
CONVECTION HAD BEGUN DVLPG ON PREFRONTAL TROUGH JUST NW THROUGH N
OF THE CWA. LOW LVL WINDS IN WAKE OF LEAD TROUGH WERE KEEPING
INFLOW INTO NRN PLAINS OR NRN NEBRASKA CONVECTION LIMITED...THUS
COVERAGE AND HOW LONG IT CAN SUSTAIN ITSELF AFTER MAX HEATING
BECOMES MORE IFFY...SPCLY FARTHER SW. NONETHELESS...WILL KEEP POPS
ALL ZONES TNGT AND TRENDS WILL BE MONITORED FOR LAST MINUTE
ADJUSTMENTS...ESPECIALLY AS TO WHERE ACTIVITY DVLPG NW THRU N OF
CWA WILL BE BY 00Z. FOR SUNDAY...BOTH NAM AND GFS CLOSE OFF MAIN
TROUGH TO OUR EAST SUNDAY AFTERNOON WITH NAM DEEPER AND A BIT
FARTHER WEST. THUS NAM WAS/IS COOLER AND MORE AGGRESSIVE WITH
PRECIPITATION OVR ERN ZONES COMPARED TO GFS. AT THIS TIME WILL
LEAN MORE TWD GFS SOLUTION BECAUSE IT HAD A BIT MORE SUPPORT FROM
12Z CMC AND WAS CLOSER TO PREV FCST. BUT EVEN IT WARRANTS A SLIGHT
INCREASE IN POPS ERN ZONES ALONG WITH SLIGHTLY COOLER TEMPERATURES
AS UPPER TROUGH AND ASSOCD -16 TO -17 DEG C TEMPS AT 500 MB SHIFT
SWD TOWARD ERN NEBR/WRN IA. DID NOT INCLUDE SUNDAY EVENING POPS
JUST YET AS SYSTEM MAY SHIFT SE OF REGION BY THEN...BUT THIS TOO
WILL NEED WATCHING.

LARGER SCALE SYNOPTIC PATTERN THEN INTO LATE NEXT WEEK APPEARS IT
WILL CONSIST OF WEST COAST RIDGING AND GREAT LAKES TROUGHING. GFS
CONTINUES ITS TREND OF LAST SEVERAL RUNS IN BEING MORE AGGRESSIVE
THAN 00Z ECMWF/CMC IN CLOSING OFF ANOTHER UPPER LOW FARTHER W THAN
THE OTHER TWO...SUGGESTING QUITE A BIT COOLER TEMPS. SINCE 12Z CMC
SOLUTION WAS STARTING TO LEAN TOWARD THE GFS...LOWERED TEMPS IN
WED/FRI PDS...BUT WL NOT GO QUITE AS COOL AS OPERATIONAL MEX
NUMBERS JUST YET. SOME SLIGHT THERMAL RIDGING/DOWNSLOPING COULD
ALLOW FOR A BIT WARMER TEMPS AHEAD OF THE NEXT TROUGH/FRONT ON TUESDAY.
TRYING TO TIME ANY LEAD EMBEDDED WAVES NEXT WEEK...OF COURSE...IS
DIFFICULT...AND ANY COULD LEAD TO SMALL PCPN CHCS. THUS LEFT POPS
BASICALLY ALONE WITH SMALL NOCTURNAL CHCS TUE NGT THRU THU NGT.
DID INSERT SMALL TSTM CHCS WITH NEXT FRONT THOUGH TUE AFTN ACROSS
NRN ZONES.

ALSO DID NOT EXTEND COOLING INTO NEXT WEEKEND SUGGESTED BY GFS. 00Z/12Z
ECMWF BEGAN BUILDING UPPER RIDGE BACK EWD ACROSS PLAINS...AND IT
APPEARED 12Z CMC WAS BEGINNING TO BUILD RIDGE EWD AS WELL BY 144
HOURS.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

CHERMOK

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>