Alert archive / Florida / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 55, NWS Jacksonville, FL

April 13, 2009Gilchrist County, Suwannee County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Apr 13, 2009, 8:24 PM EDT for Gilchrist County, Suwannee County, Florida. It was in force for 47 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: Apr 13, 2009, 8:24 PM EDT (00:24 UTC)
Expired: Apr 13, 2009, 9:11 PM EDT
In force: 47 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon

Counties Gilchrist County, FL, Suwannee County, FL

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 13, 6:53 PM EDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Jacksonville, FL (KJAX), launched 00:00Z, 0.4 hours before the alert went out and 130 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: 611 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 616 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 136 m²/s²
0-3 km storm-relative helicity: 280 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 7.2

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 Jacksonville, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 13, 2:37 PM EDT, 5 hours 47 minutes earlier.

Area forecast discussion, Apr 13, 2:37 PM EDT, 5 hours 47 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
237 PM EDT MON APR 13 2009

...TORNADO WATCH IN EFFECT FOR MOST OF AREA THRU 7 PM...

.SHORT TERM...ALL BUT THE SRN FOUR COUNTIES ARE UNDER A TOR
WATCH. WARM FRONT IS LIFTING NE ACRS SRN GA WITH A BAND OF STRONG
STORMS NEAR THE BOUNDARY EXTENDING TO A SHORTWAVE IN THE GULF OF
MEXICO. RADAR HAS INDICATED SEVERAL TORNADOES WITHIN THE SHORT
BOWING LINE SEGMENTS. STRONG LLVL SHEAR IS EVIDENT WITH NAM BUFR
SOUNDINGS SHOWING 0-3KM STORM REL HELICITY OVER 400 THIS AFTN IN
SE GA. WINDS ARE BEGINNING TO VEER TO SLY OVER INTERIOR NE FL
WHILE REMAINING SELY NEAR THE COAST. TSTMS ARE EXPECTED TO DEVELOP
OVER THE PENINSULA LATER THIS AFTN AS A RESULT OF THIS CONVERGENT
FLOW.

THE SHORTWAVE WILL CONT TO PUSH EAST TONIGHT AND OFFSHORE TUE.
BANDS CONTAINING BOWING ECHOES WILL CONTINUE THRU THE NIGHT. A
40-50 KNOT LLVL JET OVER THE REGION AND VEERING WIND PROFILES WILL
CONTINU THE THREAT FOR TORNADOES AND DAMAGING WINDS. TOR WATCHES
WILL LIKELY CONT OVER MUCH OF THE AREA THRU EARLY TUE. LATEST
THINKING IS FOR 2-3 INCHES OF RAIN ACRS SUWANNEE BASIN AND 1-2
INCHES ELSEWHERE. ALTHO THIS WOULD AGGREVATE THE FLOODING...IT
SHOULD NOT PRODUCE ANY SIGNIFICANT CHANGE.

THE COLD FRONT WILL PUSH SE OF AREA LATE TUE AND HIGH PRESSURE
WILL BUILD N OF AREA WEDNESDAY. NWLY FLOW WILL BRING COOLER AND
DRIER CONDS. TEMPS ON WED WILL BE AROUND 5 DEG BELOW CLIMO.

.LONG TERM...UPPER RIDGE WILL AMPLIFY OVER THE REGION NEAR THE END
OF THE WEEK. SURFACE HIGH PRESSURE WILL BUILD NORTH OF THE LOCAL
AREA THU-FRI WITH DRY CONDITIONS AND TEMPS SLIGHTLY BELOW CLIMO.
SAT THE SURFACE HIGH WILL SHIFT FARTHER SOUTH OVER SC/GA AND THEN
PUSHES OFFSHORE SUN AS THE NEXT FRONTAL SYSTEM DEVELOPS OVER THE
LOWER MS RIVER VALLEY. ONSHORE FLOW AND DEEPER MOISTURE RETURN TO
THE AREA LATE SAT WHICH WILL MODERATE TEMPS FURTHER TOWARD OR
SLIGHTLY ABOVE CLIMO VALUES. THE NEXT COLD FRONT BRINGS A CHANCE
OF SHOWERS AND STORMS TO THE AREA MONDAY.

&&

.AVIATION...WIDESPREAD STRATO-CU DECK ACRS THE AREA AND AT THE
TERMINALS. CIGS ARE JUST ABV 3 KFT. CLOUDS SEEM TO HAVE SCATTERED
OUT A LITTLE SOONER THAN EXPECTED. WILL WAIT UNTIL HOURLY OBS TO
DETERMINE IF CIGS WILL HOLD VFR BEFORE AMENDING. ENVIRONMENT WILL
BE FAVORABLE FOR SEVERE T-STORM DEVELOPMENT THRU THE NIGHT.

&&

.MARINE...SCA IS IN EFFECT FOR ALL LEGS THRU THIS EVNG AND
CONTINUES OFFSHORE THRU TUE EVNG. STRONG SLY WINDS WILL CONTINUE
TONIGHT AND SHIFT SW AHEAD OF THE FRONT ON TUE. OFFSHORE WINDS
ARE EXPECTED BEHIND THE FRONT TUESDAY NIGHT AND WILL DECREASE AS
HIGH PRESSURE BUILDS OVER THE REGION. NORTHEAST SURGE OF WINDS IS
EXPECTED ON THE BACK SIDE OF THE HIGH PRESSURE BY FRIDAY WITH
SMALL CRAFT ADVISORY CONDITIONS ONCE AGAIN.

&&

.FIRE WEATHER...
DRIER AIR WILL FILTER INTO THE REGION FOR ONE DAY ON WEDNESDAY. RH
VALUES WILL DROP TO NEAR 30 PCT INLAND AND AROUND 35 PCT OVER
COASTAL COUNTIES. RHS RECOVER BY THURS WITH STRONG ONSHORE FLOW.
HOWEVER BY FRI THE HIGH DRIFTS INTO GA/SC WITH DRIER AIR LIKELY
MIXING DOWN.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  61  77  47  74 /  80  50   0   0
SSI  64  78  54  73 /  70  60  10   0
JAX  64  80  52  75 /  60  70  10  10
SGJ  66  80  57  74 /  50  60  10  10
GNV  65  80  52  77 /  60  70  10  10
OCF  66  79  55  77 /  50  70  10  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY UNTIL 7 PM EDT THIS EVENING FOR DUVAL-FLAGLER-
     NASSAU-ST JOHNS.

GA...LAKE WIND ADVISORY UNTIL 7 PM EDT THIS EVENING FOR COASTAL
     CAMDEN-COASTAL GLYNN.

AM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR ALTAMAHA SOUND
     GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-
     FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-
     ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.

     SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ALTAMAHA
     SOUND GA TO FERNANDINA BEACH FL OUT 20 NM-FERNANDINA BEACH
     TO ST AUGUSTINE FL OUT 20 NM-ST AUGUSTINE TO FLAGLER BEACH
     FL OUT 20 NM.

&&

MKT/PW/RK

Hazardous weather outlook, Apr 13, 7:08 PM EDT, 1 hour 16 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.
      </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>

In the hours before

Local storm report, Apr 13, 7:36 PM EDT, 48 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.
      </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>

Special weather statement, Apr 13, 7:51 PM EDT, 33 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.
      </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>

Special weather statement, Apr 13, 8:05 PM EDT, 19 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.
      </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>

Local storm report, Apr 13, 8:07 PM EDT, 17 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.
      </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>

Special weather statement, Apr 13, 8:15 PM EDT, 9 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.
      </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>

Special weather statement, Apr 13, 8:17 PM EDT, 7 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.
      </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>

The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 13, 8:00 PM EDT	Special Marine Warning	JAX		2 hr
Apr 13, 8:05 PM EDT	Special Weather Statement	JAX	Hamilton, Suwannee	55 min
Apr 13, 8:15 PM EDT	Special Weather Statement	JAX	Putnam	30 min
Apr 13, 8:17 PM EDT	Special Weather Statement	JAX	Clay, Saint Johns	43 min
Apr 13, 8:42 PM EDT	Severe Thunderstorm Warning	JAX	Alachua, Bradford, Clay, Putnam	33 min
Apr 13, 8:48 PM EDT	Special Marine Warning	JAX		57 min
Apr 13, 8:50 PM EDT	Severe Thunderstorm Warning	JAX	Alachua, Columbia, Gilchrist, Hamilton	40 min
Apr 13, 8:53 PM EDT	Special Weather Statement	JAX	Gilchrist	52 min
Apr 13, 8:55 PM EDT	Special Weather Statement	JAX	Putnam	50 min
Apr 13, 9:06 PM EDT	Severe Thunderstorm Warning	JAX	Alachua, Bradford, Columbia, Gilchrist, Marion, Union	26 min
Apr 13, 9:15 PM EDT	Special Weather Statement	JAX	Clay	45 min
Apr 13, 9:24 PM EDT	Areal Flood Advisory	JAX	Clay, Putnam	111 min
Apr 13, 9:29 PM EDT	Special Weather Statement	JAX	Baker	46 min
Apr 13, 9:33 PM EDT	Special Weather Statement	JAX	Alachua, Bradford, Union	42 min
Apr 13, 9:47 PM EDT	Special Weather Statement	JAX	Putnam	43 min
Apr 13, 9:53 PM EDT	Special Marine Warning	JAX		67 min
Apr 13, 9:53 PM EDT	Special Weather Statement	JAX	Clay	52 min
Apr 13, 9:57 PM EDT	Special Marine Warning	JAX		93 min
Apr 13, 10:00 PM EDT	Tornado Warning	JAX	Saint Johns	30 min
Apr 13, 10:08 PM EDT	River Flood Warning	JAX	Baker, Nassau	14 hr
Apr 13, 10:10 PM EDT	Special Marine Warning	JAX		65 min
Apr 13, 10:13 PM EDT	Special Weather Statement	JAX	Marion	47 min
Apr 13, 10:15 PM EDT	Special Weather Statement	JAX	Clay, Duval	45 min
Apr 13, 10:22 PM EDT	Areal Flood Warning	JAX	Putnam	93 min
Apr 13, 10:34 PM EDT	Special Weather Statement	JAX	Flagler	41 min
Apr 13, 10:37 PM EDT	Areal Flood Warning	JAX	Saint Johns	84 min
Apr 13, 10:54 PM EDT	Special Marine Warning	JAX		55 min
Apr 13, 11:29 PM EDT	Special Marine Warning	JAX		2 hr
Apr 14, 3:31 AM EDT	Lake Wind Advisory	JAX	Baker, Bradford, Flagler, Gilchrist, Nassau, Suwannee and 1 more	15 hr
Apr 14, 4:52 AM EDT	Fire Weather Watch	JAX	Baker, Bradford, Flagler, Gilchrist, Nassau, Suwannee and 1 more	24 hr
Apr 14, 5:23 AM EDT	Special Weather Statement	JAX	Marion	37 min
Apr 14, 5:35 AM EDT	Special Weather Statement	JAX	Marion	25 min
Apr 14, 7:56 AM EDT	Special Weather Statement	JAX	Marion	49 min
Apr 14, 8:25 AM EDT	Severe Thunderstorm Warning	JAX	Marion	50 min
Apr 14, 8:38 AM EDT	Special Weather Statement	JAX	Putnam	52 min
Apr 14, 8:57 AM EDT	Special Weather Statement	JAX	Marion	48 min
Apr 14, 9:10 AM EDT	Special Weather Statement	JAX	Flagler, Putnam, Saint Johns	50 min
Apr 14, 9:26 AM EDT	Severe Thunderstorm Warning	JAX	Alachua, Marion	23 min
Apr 14, 9:32 AM EDT	Special Weather Statement	JAX	Alachua, Bradford, Clay, Duval, Putnam, Saint Johns and 1 more	88 min
Apr 14, 9:37 AM EDT	Special Marine Warning	JAX		113 min
Apr 14, 9:56 AM EDT	Wind Advisory	JAX	Bradford, Flagler, Gilchrist, Union	113 min
Apr 14, 10:17 AM EDT	Special Marine Warning	JAX		118 min
Apr 14, 11:29 AM EDT	Special Marine Warning	JAX		61 min

Nearby

Severe Thunderstorm Warnings in Florida, 2009 Every severe thunderstorm warning in 2009

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.