Alert archive / Nebraska / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 129, NWS Omaha, NE

May 14, 2007Seward County, Nebraska

NWS Omaha, NE issued this severe thunderstorm warning at May 14, 2007, 6:30 PM CDT for Seward County, Nebraska. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 14, 2007, 6:30 PM CDT (23:30 UTC)
Expired: May 14, 2007, 7:00 PM CDT
In force: 30 min
Issued by: NWS Omaha, NE
Area: Counties, with a storm outline in the text

County Seward County, NE

The radar

The Omaha radar (KOAX), 82 km from the middle of the area, began a volume at 23:33 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 14, 4:27 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.5 hours before the alert went out and 81 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 106 J/kg
Mixed-layer CIN: -500 J/kg
Mixed-layer LCL: 1678 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at May 14, 2:50 PM CDT, 3 hours 40 minutes earlier.

Area forecast discussion, May 14, 2:50 PM CDT, 3 hours 40 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
250 PM CDT MON MAY 14 2007

.DISCUSSION...

INITIAL CONCERNS WILL DEAL WITH THE COLD FRONT MOVING THROUGH THE
AREA TONIGHT THEN CHANCE OF PRECIP WEDNESDAY AND LATE IN THE
EXTENDED PERIOD.

18Z SURFACE ANALYSIS SHOWED THE COLD FRONT OVER THE NORTHEAST CORNER
OF NEBRASKA FROM NEAR KLCG THROUGH KBVN THEN EXTENDING INTO
SOUTHWEST NEBRASKA. FRONT APPEARS TO BE A LITTLE FASTER THAN
INDICATED BY 12Z NAM OR GFS AND MORE IN LINE WITH RUC. MORNING UA
ANALYSIS SHOWED MOISTURE SOMEWHAT LIMITED AT BOTH 850 AND 700MB.
SOME SCATTERED SHOWERS ON THE BACKSIDE OF THE FRONT WITH WINDY AND
WARM CONDITONS IN ADVANCE. RUC FORECAST SOUNDINGS MUCH LESS
AGGRESSIVE WITH MOISTURE AND INSTABILITY THAN NAM AND ALSO FASTER
WITH TIMING OF FRONT INTO KOMA BY 01Z. WILL CONTINUE WITH THE LIKELY
POPS FOR ALL BUT THE FAR NWRN PORTION OF THE CWA FOR TONIGHT WITH
PRECIP ENDING IN THE SERN CORNER TUESDAY MORNING. SHORT WAVE
DROPPING INTO THE REGION ON WEDNESDAY PULLS DOWN A SECONDARY SURGE
OF COOLER AIR BUT THIS STAYS MAINLY NORTHEAST OF OUR AREA. SOME
ELEVATED INSTABILITY INDICATED WEDNESDAY AFTERNOON INTO EARLY
EVENING BUT LOWER LEVELS PRETTY DRY SO HAVE LEFT OUT ANY POPS FOR
NOW WITH JUST SOME INCREASE IN SKY COVER FROM EARLIER FORECAST.
WARMING STARTS TO RETURN ON THURSDAY AS HIGH SHIFTS TO THE EAST AND
UPPER RIDGE BEGINS TO REBUILD INTO THE CENTRAL PART OF THE NATION.

WARMING THEN CONTINUES IN THE EXTENDED PERIOD THROUGH THE WEEKEND
BEFORE NEXT SYSTEM APPROACHES SUNDAY NIGHT AND MONDAY. INTRODUCED
SOME SLIGHT POPS FOR MONDAY BUT TIMING UNCERTAIN THAT FAR OUT.

&&

.AVIATION...

TIMING OF WIND SHIFT AND PRECIPITATION CHANCES WITH APPROACHING COLD
FRONT WILL BE OF MOST CONCERN FOR AVIATORS. STRONG SOUTHWEST WINDS
GUSTING OVER 25 KTS WILL CONTINUE INTO THE EARLY EVENING...WITH
SWITCH TO NORTHWEST WIND AT KOFK NEAR 00Z...AND KLNK/KOMA AREAS
AROUND 04Z. MVFR CIGS AND IFR VSBYS EXPECTED WITH THUNDERSTORMS THAT
DEVELOP ALONG AND JUST BEHIND FRONTAL BOUNDARY...WITH LINGERING
POTENTIAL FOR MVFR SHOWERS AND CIGS FOR ABOUT 4 HOURS AFTER HEAVIEST
RAIN. VFR CONDITIONS WITH NORTH WINDS GUSTING OVER 25 KTS SHOULD BE
THE RULE AFTER 12Z-14Z TUESDAY.

&&

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

FOBERT/DERGAN

Hazardous weather outlook, May 14, 4:49 PM CDT, 1 hour 41 minutes before

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In the hours before

Local storm report, May 14, 4:47 PM CDT, 1 hour 43 minutes before

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<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.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 14, 4:23 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Washington	37 min
May 14, 6:57 PM CDT	Severe Thunderstorm Warning	OAX	Seward	33 min
May 14, 4:52 PM CDT	Severe Thunderstorm Warning	OAX	Monona	23 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2007 Every severe thunderstorm warning in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.