Alert archive / Minnesota / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 154, NWS Grand Forks, ND

July 15, 1999Otter Tail County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 15, 1999, 5:16 PM CDT for Otter Tail County, Minnesota. It was in force for 34 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jul 15, 1999, 5:16 PM CDT (22:16 UTC)
Expired: Jul 15, 1999, 5:50 PM CDT
In force: 34 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

County Otter Tail County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 175 km from the middle of the area, began a volume at 22:18 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.

What was reported inside it

Time	Report	Where	Remark
Jul 15, 5:35 PM CDT	Thunderstorm Wind 56	Parkers Prairie, MN

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 15, 2:45 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.3 hours before the alert went out and 239 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: 1105 J/kg
Mixed-layer CIN: -429 J/kg
Mixed-layer LCL: 1400 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 28 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 Grand Forks, ND wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 15, 2:15 PM CDT, 3 hours 1 minute earlier.

Area forecast discussion, Jul 15, 2:15 PM CDT, 3 hours 1 minute before

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
215 PM CDT THU JUL 15 1999

...MAIN FORECAST CHALLENGE LOCATION/STRENGTH OF CONVECTIVE ACTIVITY
OVER FA THIS EVENING...

MODELS INTIALIZED WELL THIS AM BUT BEGIN TO DIVERGE BY 18Z AT THE SFC.
ALL DO AGREE ON TAKING SFC LOW NE ACROSS NRN RRV BY EARLY EVENING WITH
LOW CONTINUIING TO TRACK INTO CENTRAL ONTARIO BY 12 FRIDAY. ETA DID
BEST WITH LOW LEVEL MOISTURE OVER FA...AND WITH PAST PERFORMANCE WILL
FOLLOW IT THIS PACKAGE.

.SHORT TERM...BROAD BAND OF SHOWERS AND THUNDERSTORMS CONTINUE TO PUSH
EAST ACROSS ND THIS AM AHEAD OF SFC LOW AND 5H VORT LOBE. ERN ZONES
HAVE HAD MORE SUN TODAY WHICH HAS PUSHED TEMPS UP INTO THE UPPER 80S TO
LOWER 90S WITH DEWPOINTS IN THE 70S MOST AREAS. LAPS SHOWS BEST
MOISTURE CONVERGENCE OVER FAR NW MN THIS AFTERNOON WITH 88D SHOWING
RAPID CONVECTIVE DEVELOPMENT THERE ATTM. HIGHEST CAPES FROM LAPS DATA
OVER SRN ZONES HOWEVER WITH ALL AREAS ALONG AND EAST OF RRV BECOMING
MORS UNSTABLE WITH TIME. BEST DIRECTIONAL SHEAR NOTED OVER FAR NW MN
PER ETA...BUT HIGHEST HELICITIES SHIFT NORTH INTO CANADA BY 0Z.
THINKING IS THAT BEST POTENTIAL FOR SVR THUNDERSTORMS TO BE OVER MN
ZONES INTO SE ND THIS EVENING WITH LARGE HAIL AND DAMAGING WINDS THE
MAIN THREAT WITH THE LOSS OF DIRECTIONAL SHEAR IN THE LOWER LEVELS.
ONGOING CONVECTIVE ACTIVITY OVER NORTHEASTERN ND HAS WORKED THE
ATMOSPHERE OVER ENOUGH THERE SO SEVERE THREAT LESSENED IN THIS AREA.
STILL EXPECT STRONG STORMS THIS AREA THIS EVENING/OVERNIGHT AS COLD
FRONT BEGINS TO MOVE IN.

TIMING OF FROPA OVER FA TONIGHT PROBLEMATIC AS MISSING ETA DATA FOR
THOSE TIMEFRAMES. ATTM EXPECT FRONT TO BE THROUGH ALL BUT EXTREME SE
ZONES BY 12Z. DRIER AND COOLER AIR MOVING IN BEHIND FRONT...BUT WITH
NGM UNDERPLAING DEWPOINTS OVER REGION WILL STAY ABOVE FWC NUMBERS.

.LONG TERM...HIGH PRESSURE BUILDS INTO FA BEHIND COLD FRONT WITH DRIER
AIR FILTERING IN. COOLING IN MID LEVELS COMBINED WITH SOME DAYTIME
HEATING SHOULD BE ENOUGH TO TRIGGER INSTABILITY SHOWERS OVER THE FA
WITH HIGHEST POPS OVER THE NORTHEAST. WILL GO WITH 20 POPS ERN ND AND
WEST CENTRAL MN...WITH 30 POPS ACROSS FAR NE. WILL LEAN CLOSER TO
COOLER FAN NUMBERS NORTH AS ETA/AVN SHOWING A SECONDARY COOL SURGE
THERE...AND SPLIT DIFFERENCE WITH FWC/FAN OVER THE SOUTH. SFC HIGH
DOMINATING REGION FOR THE START OF THE WEEKEND WITH DRY AND MILD
CONDITIONS PREVAILING.

.EXTENDED...MRF PRETTY CONSISTENT FROM RUN TO RUN IN BUILDING 5H RIDGE
OVER FA. WEAK S/W MOVING INTO THE RIDGE SATURDAY NIGHT WILL BRING A
SLIGHT CHANCE FOR THUNDERSTORMS TO FA THEN WITH A BETTER CHANCE IN
RETURN FLOW ON SUNDAY. COLD FRONT TO SAG SOUTH ACROSS REGION SUNDAY
NIGHT. WHILE WEAK S/W CONTINUE TO PASS OVER AREA...ONLY EXPECT SCT
SHOWERS AS SFC HIGH REMAINS IN PLACE. WILL CONTINUE TREND OF COOLER
THAN NORMAL HIGHS AND NEAR SEASONAL LOWS THROUGH EXTENDED.

THANKS FOR COORDINATION DLH.

.FGF...NONE.

RJT

In the hours before

Local storm report, Jul 15, 4:40 PM CDT, 36 minutes before

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Local storm report, Jul 15, 4:40 PM CDT, 36 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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The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 15, 8:31 AM CDT	Severe Thunderstorm Warning	FGF	Pembina	34 min
Jul 15, 3:50 PM CDT	Severe Thunderstorm Warning	FGF	Richland	35 min
Jul 15, 9:30 AM CDT	Severe Thunderstorm Warning	FGF	Roseau	35 min
Jul 15, 10:43 AM CDT	Severe Thunderstorm Warning	FGF	Lake of the Woods	32 min
Jul 15, 3:37 PM CDT	Tornado Warning	FGF	Lake of the Woods	33 min
Jul 15, 4:04 PM CDT	Severe Thunderstorm Warning	FGF	Otter Tail	31 min
Jul 15, 4:35 PM CDT	Severe Thunderstorm Warning	FGF	Becker	30 min
Jul 15, 4:44 PM CDT	Severe Thunderstorm Warning	FGF	Otter Tail	36 min
Jul 15, 5:01 PM CDT	Severe Thunderstorm Warning	FGF	Becker, Hubbard	34 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.