Alert archive / Iowa / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 107, NWS Des Moines, IA

July 2, 1999Franklin County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 2, 1999, 7:10 PM CDT for Franklin County, Iowa. It was in force for 50 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: Jul 2, 1999, 7:10 PM CDT (00:10 UTC)
Expired: Jul 2, 1999, 8:00 PM CDT
In force: 50 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Franklin County, IA

The radar

The Des Moines radar (KDMX), 118 km from the middle of the area, began a volume at 00:13 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 0.2 hours before the alert went out and 237 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1357 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 226 m²/s²
0-3 km storm-relative helicity: 482 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Des Moines, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 2, 3:45 PM CDT, 3 hours 25 minutes earlier.

Area forecast discussion, Jul 2, 3:45 PM CDT, 3 hours 25 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
345 PM CDT FRI JUL 2 1999

THUNDERSTORM COMPLEX CURRENTLY WORKING ITS WAY ACROSS CENTRAL IOWA
WITH THE STRONGEST STORMS LOCATED IN SOUTHERN DALLAS AND WEBSTER
COUNTIES. THUNDERSTORM PROPAGATING TO THE SOUTHEAST INTO UNSTABLE
ATMOS. LOW LEVEL SHEAR WILL HELP KEEP SOME THUNDERSTORM SEVERE.
CAPPING OVER SOUTHEAST SECTION OF THE DES MOINES FORECAST AREA IS
RELATIVELY WEAK WITH CAPPING STRONGER OVER THE REMAINDER OF THE
FORECAST AREA. DALLAS COUNTY STORM IS MOVING ALONG OR JUST TO THE
NORTH OF THE WARM FRONTAL BOUNDARY. 850 MB WARM FRONT OVER CENTRAL
SECTION OF THE STATE. THINKING ACTIVITY NORTH OF THE WARM WILL
CONTINUE UNDER THE LOW LEVEL WARM ADVECTION AND LIFT OVER THE FRONT.
THIS IS THE REASON FOR THE HIGHER POPS IN NORTHERN SECTIONS OF THE
FORECAST AREA. WARM FRONT CONTINUES TO LIFT NORTH TONIGHT SHIFTING
THE THREAT NORTHWARD INTO SOUTHERN MINNESOTA.  WARM ADVECTION
CONTINUES SATURDAY...QUICKLY STRENGTHENING THE CAP BY MIDDAY SO THAT
ANY CHANCE OF CONVECTION WILL BE SUPPRESSED.

EXTENDED...
WILL BE HOT AND HUMID SUNDAY AND MONDAY. AS DAVENPORT NOTED A COLD
FRONT ON MONDAY INTO MONDAY NIGHT WILL HELP COOL THE ATMOSPHERE OFF
TUESDAY AND WEDNESDAY. AGREE AS WELL ENOUGH CAPPING AND STABILITY TO
KEEP ANY ACTIVITY SUPPRESSED.

.DSM...NONE

In the hours before

Local storm report, Jul 2, 6:20 PM CDT, 50 minutes before

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Local storm report, Jul 2, 6:20 PM CDT, 50 minutes before

<!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.
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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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Local storm report, Jul 2, 6:47 PM CDT, 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
647 PM CDT FRI JUL 02 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0330 PM    2 S NEW PROVIDENCE        IA    WIND DAMAGE
07/02/99   HARDIN                          LARGE TREE LIMBS DOWN
                                           AND DAMAGE TO FARM
                                           OUTBUILDINGS.

0530 PM    PILOT MOUND               IA    WIND DAMAGE
07/02/99   BOONE                           TREES DOWN AND WINDOWS
                                           BROKEN.

Local storm report, Jul 2, 6:47 PM CDT, 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
647 PM CDT FRI JUL 02 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0330 PM    2 S NEW PROVIDENCE        IA    WIND DAMAGE
07/02/99   HARDIN                          LARGE TREE LIMBS DOWN
                                           AND DAMAGE TO FARM
                                           OUTBUILDINGS.

0530 PM    PILOT MOUND               IA    WIND DAMAGE
07/02/99   BOONE                           TREES DOWN AND WINDOWS
                                           BROKEN.

Local storm report, Jul 2, 6:55 PM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
655 PM CDT FRI JUL 02 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0625 PM    AMES                      IA    2.5 INCH HAIL
07/02/99   STORY

Local storm report, Jul 2, 6:55 PM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
655 PM CDT FRI JUL 02 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0625 PM    AMES                      IA    2.5 INCH HAIL
07/02/99   STORY

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 2, 7:26 PM CDT	Severe Thunderstorm Warning	DMX	Hardin	49 min
Jul 2, 9:53 PM CDT	Flash Flood Warning	DMX	Black Hawk, Butler	4 hr
Jul 2, 10:16 PM CDT	Flash Flood Warning	DMX	Grundy, Hardin	3 hr

Nearby

Severe Thunderstorm Warnings in Iowa, 1999 Every severe thunderstorm warning in 1999

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.