Alert archive / Missouri / Areal Flood Advisories in 2011

Areal Flood Advisory 3, NWS St. Louis, MO

April 19, 20114 counties in Missouri; Madison County, Monroe County, Saint Clair County, Illinois

NWS St. Louis, MO issued this areal flood advisory at Apr 19, 2011, 6:21 AM CDT for 4 counties in Missouri; Madison County, Monroe County, Saint Clair County, Illinois. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Apr 19, 2011, 6:21 AM CDT (11:21 UTC)
Expired: Apr 19, 2011, 9:00 AM CDT
In force: 3 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon

Counties Madison County, IL, Monroe County, IL, Saint Clair County, IL, City of Saint Louis, MO, Jefferson County, MO, Saint Charles County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 40 km from the middle of the area, began a volume at 11:22 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

Lincoln, IL (KILX), launched 00:00Z, 11.4 hours before the alert went out and 228 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: 1035 m above ground
0-6 km bulk shear: 69 kt
0-1 km storm-relative helicity: 194 m²/s²
0-3 km storm-relative helicity: 347 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 areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this areal flood advisory went out at Apr 19, 4:49 AM CDT, 1 hour 32 minutes earlier.

Area forecast discussion, Apr 19, 4:49 AM CDT, 1 hour 32 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
449 AM CDT TUE APR 19 2011

.DISCUSSION...
/449 AM CDT TUE APR 19 2011/

...SIGNIFICANT SEVERE THUNDERSTORM OUTBREAK THIS AFTERNOON AND
EVENING...

DEALING WITH SEVERE ACTIVITY EARLY THIS MORNING...SO WILL SEND OUT A
BRIEF DISCUSSION ABOUT TODAY AND TONIGHT. LATEST SURFACE ANALYSIS
SHOWS SURFACE FRONT REMAINS STALLED JUST SOUTH OF I-70. STORMS HAVE
BEGUN TO FIRE EARLY THIS MORNING ON NOSE OF LOW LEVEL JET...OVER
CENTRAL MO AND ARE MOVING TO THE NORTHEAST. NUMEROUS REPORTS OF
LARGE HAIL WITH THESE STORMS.

FOR THIS MORNING...WILL CONTINUE TO SEE ONGOING ACTIVITY INCREASE IN
COVERAGE AND INTENSITY THROUGH THE MORNING HOURS...BEFORE
DIMINISHING TOWARDS NOONTIME. THEN MORE SIGNIFICANT ROUND OF STORMS
EXPECTED TO FIRE UP THIS AFTERNOON AS STRONG AREA OF LOW PRESSURE
LIFTS NORTHEASTWARD THROUGH MO...WITH IT NEAR KSTL AROUND 21Z.
MODELS COMING INTO BETTER AGREEMENT WITH FASTER MOVEMENT THROUGH
REGION THIS AFTERNOON AND EVENING...AND PCPN COMING TO AN END BY 06Z
MOST LOCATIONS.

SPC HAS KEPT SOUTHEASTERN HALF OF CWA IN A MODERATE RISK FOR THIS
AFTERNOON AND EVENING...WITH THE MAIN THREATS BEING STRONG
TORNADOES...HAIL LARGER THAN GOLF BALL SIZE AND DAMAGING STRAIGHT
LINE WIND GUSTS. SO DESPITE STRONG CAP TO DEVELOP OVER REGION AFTER
INITIAL ROUND OF ACTIVITY...STRONG ASCENT TO OVERSPREAD THE REGION
HELPING STORMS TO INITIATE BETWEEN 19Z AND 22Z. EXPECT EPISODE TO
START OFF AS SUPERCELLS THEN EVOLVE INTO A SEVERE LINEAR MCS DURING
THE EVENING AS IT PROGRESSES FURTHER EAST...EXITING THE CWA SHORTLY
AFTER 06Z.

DRY AND COOLER WEATHER EXPECTED ON WEDNESDAY...WITH ONLY MINOR
ADJUSTMENTS BEYOND THAT TO THE FORECAST.

BYRD
&&

.AVIATION...
/1206 AM CDT TUE APR 19 2011/

SOME QUESTION REMAINS REGARDING CONVECTION TONIGHT. AREA OF PRECIP
WILL LINGER NEAR UIN OVERNIGHT. NEAR COU/SUS...CONVECTION MAY
BEGIN LATER TONIGHT AS LLJ BEGINS TO INCREASE. OTHERWISE...CIGS
WILL REMAIN LOW MVFR TO IFR OVERNIGHT WITH CIGS GRADUALLY
LOWERING. UIN IS EXPECTED TO REMAIN N OF THE WRMFNT ON TUES AND
SHUD THEREFORE EXPERIENCE LOW MVFR CIGS FOR THE ENTIRE TAF PERIOD.
KEPT PRECIP VAGUE AS UNCERTAIN HOW WIDESPREAD PRECIP WILL BE N OF
THE WRMFNT. FOR COU/SUS...EXPECT TSRA...VERY POSSIBLE SEVERE...
JUST AHEAD OF THE APPROACHING CDFNT AND SFC LOW. TIMING OF THIS
CDFNT REMAINS SOMEWHAT UNCERTAIN...BUT IS A LITTLE FASTER THAN
PREVIOUS GUIDANCE. BEHIND THE FNT...CIGS WILL RAPIDLY DROP INTO
THE LOW MVFR RANGE AGAIN. CAN NOT RULE OUT LIGHT FG AS WELL...BUT
WILL KEEP OUT OF TAF FOR NOW.

SPECIFICS FOR KSTL...SOME QUESTION REMAINS REGARDING CONVECTION
TONIGHT. CONVECTION MAY BEGIN LATER TONIGHT AS LLJ BEGINS TO
INCREASE AND VEER. OTHERWISE...CIGS WILL REMAIN LOW MVFR AND
EXPECTED TO DRIP TO IFR OVERNIGHT. FOR TUESDAY...EXPECT
TSRA...VERY POSSIBLE SEVERE...JUST AHEAD OF THE APPROACHING CDFNT
AND SFC LOW. TIMING OF THIS CDFNT REMAINS SOMEWHAT UNCERTAIN...BUT
IS A LITTLE FASTER THAN PREVIOUS GUIDANCE. BEHIND THE FNT...CIGS
WILL RAPIDLY DROP INTO THE LOW MVFR RANGE AGAIN. CAN NOT RULE OUT
LIGHT FG AS WELL...BUT WILL KEEP OUT OF TAF FOR NOW.

TILLY
&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

WFO LSX

Hazardous weather outlook, Apr 19, 4:02 AM CDT, 2 hours 19 minutes before

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In the hours before

Local storm report, Apr 19, 5:53 AM CDT, 28 minutes before

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Local storm report, Apr 19, 5:54 AM CDT, 27 minutes before

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Local storm report, Apr 19, 6:03 AM CDT, 18 minutes before

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Local storm report, Apr 19, 6:09 AM CDT, 12 minutes before

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Local storm report, Apr 19, 6:12 AM CDT, 9 minutes before

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Local storm report, Apr 19, 6:14 AM CDT, 7 minutes before

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The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 19, 2:51 AM CDT	Severe Thunderstorm Warning	LSX	Cole, Moniteau, Osage	39 min
Apr 19, 3:19 AM CDT	Severe Thunderstorm Warning	LSX	Boone, Callaway, Cole, Moniteau, Osage	41 min
Apr 19, 3:26 AM CDT	Severe Thunderstorm Warning	LSX	Callaway, Gasconade, Osage	49 min
Apr 19, 3:39 AM CDT	Severe Thunderstorm Warning	LSX	Moniteau	21 min
Apr 19, 3:57 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Boone, Callaway, Cole, Franklin, Gasconade and 4 more	48 min
Apr 19, 4:35 AM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Pike	40 min
Apr 19, 4:43 AM CDT	Severe Thunderstorm Warning	LSX	Franklin, Gasconade, Montgomery, Warren	47 min
Apr 19, 4:58 AM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Gasconade, Washington	32 min
Apr 19, 5:23 AM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Saint Charles, Warren, Washington	37 min
Apr 19, 5:43 AM CDT	Severe Thunderstorm Warning	LSX	Franklin, Jefferson, Saint Charles, Saint Louis, Washington	47 min
Apr 19, 6:22 AM CDT	Severe Thunderstorm Warning	LSX	Jefferson	38 min
Apr 19, 6:26 AM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis, City of Saint Louis	49 min
Apr 19, 7:08 AM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis, City of Saint Louis	37 min
Apr 19, 8:05 AM CDT	River Flood Warning	LSX	Saint Charles	30 hr
Apr 19, 11:06 AM CDT	River Flood Warning	LSX	Lincoln	19 days
Apr 19, 11:33 AM CDT	River Flood Warning	LSX	Jefferson, Saint Louis	30 days
Apr 19, 3:46 PM CDT	Severe Thunderstorm Warning	LSX	Pike, Ralls	44 min
Apr 19, 3:48 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Montgomery, Pike	42 min
Apr 19, 3:54 PM CDT	Severe Thunderstorm Warning	LSX	Boone, Callaway, Cole, Osage	51 min
Apr 19, 3:59 PM CDT	Tornado Warning	LSX	Pike	46 min
Apr 19, 4:24 PM CDT	Severe Thunderstorm Warning	LSX	Cole, Franklin, Gasconade, Osage	51 min
Apr 19, 4:31 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Montgomery, Warren	44 min
Apr 19, 4:31 PM CDT	Tornado Warning	LSX	Pike	44 min
Apr 19, 4:41 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis	49 min
Apr 19, 5:01 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Montgomery, Saint Charles, Warren	44 min
Apr 19, 5:13 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Gasconade, Montgomery, Saint Charles, Warren	47 min
Apr 19, 5:28 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis	47 min
Apr 19, 5:44 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln	34 min
Apr 19, 5:56 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Saint Charles, Warren	34 min
Apr 19, 5:58 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Gasconade	32 min
Apr 19, 6:12 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Saint Charles, Saint Louis, Warren	48 min
Apr 19, 6:14 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Warren	31 min
Apr 19, 6:15 PM CDT	Severe Thunderstorm Warning	LSX	Reynolds	60 min
Apr 19, 6:30 PM CDT	Flash Flood Warning	LSX	Saint Charles	3 hr
Apr 19, 6:37 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Madison, Reynolds, Saint Francois, Washington	53 min
Apr 19, 6:45 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Saint Charles	30 min
Apr 19, 6:51 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Reynolds	39 min
Apr 19, 6:56 PM CDT	Areal Flood Advisory	LSX	Franklin, Warren	5 hr
Apr 19, 6:56 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis, City of Saint Louis	64 min
Apr 19, 5:14 AM CDT	Severe Thunderstorm Warning	LSX	Greene, Pike	31 min
Apr 19, 6:56 AM CDT	Severe Thunderstorm Warning	LSX	Monroe, Saint Clair	49 min
Apr 19, 7:36 AM CDT	Severe Thunderstorm Warning	LSX	Bond, Macoupin, Madison, Montgomery	39 min
Apr 19, 8:07 AM CDT	Severe Thunderstorm Warning	LSX	Bond, Fayette, Montgomery	38 min
Apr 19, 8:25 AM CDT	Severe Thunderstorm Warning	LSX	Fayette, Marion	29 min
Apr 19, 8:41 AM CDT	Severe Thunderstorm Warning	LSX	Fayette	34 min
Apr 19, 11:18 AM CDT	River Flood Warning	LSX	Calhoun, Greene, Jersey	85 days
Apr 19, 4:18 PM CDT	Tornado Warning	LSX	Calhoun, Greene, Pike	42 min
Apr 19, 4:59 PM CDT	Tornado Warning	LSX	Greene, Pike	46 min
Apr 19, 5:28 PM CDT	Severe Thunderstorm Warning	LSX	Greene, Jersey, Macoupin	47 min
Apr 19, 5:36 PM CDT	Tornado Warning	LSX	Macoupin	39 min
Apr 19, 5:42 PM CDT	Severe Thunderstorm Warning	LSX	Greene	34 min
Apr 19, 6:01 PM CDT	Tornado Warning	LSX	Montgomery	44 min
Apr 19, 6:05 PM CDT	Tornado Warning	LSX	Macoupin, Montgomery	40 min
Apr 19, 6:14 PM CDT	Severe Thunderstorm Warning	LSX	Jersey, Macoupin, Madison	61 min
Apr 19, 6:31 PM CDT	Tornado Warning	LSX	Montgomery	27 min

Nearby

Areal Flood Advisories in Missouri, 2011 Areal Flood Advisories in Illinois, 2011 Every areal flood advisory in 2011

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.