Severe Thunderstorm Warning 187, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
116 PM CDT SUN APR 26 2015

.AVIATION...
THICKER CLOUD COVER ACROSS NORTHWEST OKLAHOMA WILL LIKELY
KEEP IFR CONDITIONS IN PLACE THROUGH AT LEAST MID TO LATE
AFTERNOON. ELSEWHERE...CLOUDS ARE GRADUALLY DECREASING ON
SOUTHERN EDGE OF CLOUD COVER IN CENTRAL OKLAHOMA.

SEVERE STORMS MAY IMPACT TERMINALS THROUGH AT LEAST THE EARLY
EVENING (SPS,LAW,HBR). STORMS ARE EXPECTED TO SPREAD NORTHWARD
WITH A GRADUALLY DECREASE IN INTENSITY. MVFR TO IFR CONDITIONS
ARE LIKELY WITH STRONGER CONVECTION.

SHOWERS AND EMBEDDED STORMS WILL LINGER INTO THE OVERNIGHT
AND MONDAY MORNING WITH IFR CONDITIONS...ESPECIALLY CENTRAL
AND PART OF NORTHERN OKLAHOMA.

&&

.PREV DISCUSSION... /ISSUED 1102 AM CDT SUN APR 26 2015/

UPDATE...
PRECIP/WX... TEMPS...

DISCUSSION...
OBSERVING CURRENT VIS SAT... CONVECTION HAS ALREADY STARTED NEAR
ABILENE TEXAS. HIGH CLOUDS ARE QUICKLY BUILDING ACROSS THE LLANO
ESTACADO AND WEST TEXAS AS WELL... INDICATING ENHANCED LIFT FROM
THE H5 LOW CROSSING NM AT PRESENT TIME. FROM ALL INDICATIONS...
LOOKS LIKE INITIATION ACROSS WRN N TX AND SWRN OK MAY BE MOVING UP
A FEW HOURS... TO LATE THIS AM/EARLY AFTN. BUFR SOUNDINGS FROM THE
RAP HAVE THE CAP ERODING FAIRLY QUICKLY THROUGH ABOUT 19-20Z
ACROSS NRN TX. 15Z MESOANALYSIS FROM SPC HAS SBCAPE SLOWLY
INCREASING NORTHWARD TOWARD THE NRN BRAZOS RIVER VALLEY... 1500 TO
2000 J/KG. WITH AN EARLIER START... HAIL AND WIND WILL BE THE
PRIMARY CONCERN AS LL WIND FIELDS WILL NOT BE AS CONDUCIVE TO
TORNADIC DEVELOPMENT THIS EARLY... BUT DEEP LAYER SHEAR WILL
SUPPORT LARGE HAIL DEVELOPMENT ACROSS NORTH TEXAS/TEXOMA. AS WE
MOVE INTO THE MID TO LATE AFTN... SOME BACKING OF THE SFC WINDS
ACROSS TEXOMA WILL INCREASE LL SHEAR/HELICITIES... WHICH WOULD
INCREASE THE CHANCE FOR A TORNADO OR TWO WITH THE STRONGEST STORMS
ACROSS TEXOMA... BUT CONDITIONS WILL BE HIGHLY CONDITIONAL ON THE
IMPACTS TO THE ATMOSPHERE FROM THE EARLY CONVECTION... WHICH COULD
THROW A WRENCH INTO SEVERE CHANCES INTO THE AFTN. CONDITIONS WILL
BE EVOLVING QUICKLY THROUGH THE AFTN.... SO STAY WEATHER AWARE.

JTK

PREV DISCUSSION... /ISSUED 319 AM CDT SUN APR 26 2015/

DISCUSSION...
WEAK COLD FRONT LOCATED JUST SOUTH OF I-40 THIS MORNING WILL CONT
TO MOVE SLOWLY SOUTH TOWARD THE RED RIVER BY LATE THIS MORNING.
THIS FRONT IS EXPECTED TO STALL THIS AFTN AND PERHAPS LIFT BACK
NORTH ACROSS SOUTHWEST OKLAHOMA AS AN AREA OF SFC LOW PRES
DEVELOPS ACROSS SOUTHERN TX PANHANDLE. A DRYLINE WILL STRETCH
SOUTH FROM THIS SFC LOW SOUTHWARD ACROSS WEST TX. THESE BOUNDARIES
WILL BE THE FOCI FOR SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTN
AND EVENING.

MODELS HAVE SHOWN A TREND IN DEVELOPING PRECIP A BIT QUICKER
TODAY AS LIFT FROM THE APPROACHING UPPER LOW BEGINS TO INFLUENCE
THE AREA THIS AFTN. INCREASING MOISTURE AND FAVORABLE WIND FIELDS
WILL SUPPORT SUPERCELLS CAPABLE OF VERY LARGE HAIL... ESPECIALLY
ACROSS SOUTHWEST OKLAHOMA SOUTHWARD INTO NORTH TEXAS. THERE WILL
ALSO BE A WINDOW OF OPPORTUNITY FOR A TORNADO OR TWO IN THESE
AREAS AS WELL LATE THIS AFTN INTO THE EARLY EVENING HOURS.

WE EXPECT TO SEE A GENERAL DOWNWARD TREND IN SEVERE POTENTIAL AS
WE APPROACH MIDNIGHT AS WE LOSE OUR INSTABILITY. HOWEVER WE WILL
TRANSITION TO HEAVY RAINFALL THAT WILL LIKELY LINGER THROUGH THE
DAY ON MONDAY INTO MONDAY NIGHT AND EARLY TUESDAY BEFORE THE
PRECIP ENDS. THE MODELS HAVE SHOWN A SLIGHT SHIFT FURTHER NORTH
AND EAST WITH THE HEAVIEST PRECIP... BUT WIDESPREAD 2 TO 3 INCH
AMOUNTS... WITH ISOLATED 4 INCH AMOUNTS ARE A LIKELY SCENARIO.
CONTEMPLATED FLOOD WATCH... BUT DUE TO THESE SHIFTS IN TIMING AND
LOCATION... WILL HOLD OFF FOR NOW AND LET DAY SHIFT SEE IF THESE
ISSUES RESOLVE THEMSELVES WITH LATER MODEL RUNS.

BEYOND TUESDAY... IT STILL APPEARS THAT WE WILL SEE A MUCH
QUIETER PERIOD WITH NO ADDITIONAL PRECIP CHANCES AND MILD TEMPS.
THIS WILL TAKE US INTO THE FIRST WEEKEND OF MAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  56  59  48  61 /  80  80  70  30
HOBART OK         56  61  45  61 /  80  80  60  30
WICHITA FALLS TX  59  65  49  62 /  70  70  60  30
GAGE OK           48  55  40  63 /  80  80  60  20
PONCA CITY OK     51  60  46  65 /  60  60  50  30
DURANT OK         58  65  50  61 /  70  70  70  40

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

<!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>

<!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>