Alert archive / Alabama / Flash Flood Warnings in 2017

Flash Flood Warning 15, NWS Mobile, AL

May 20, 2017Mobile County, Alabama

NWS Mobile, AL issued this flash flood warning at May 20, 2017, 8:25 PM CDT for Mobile County, Alabama. It was in force for 6 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 20, 2017, 8:25 PM CDT (01:25 UTC)
Expired
May 21, 2017, 2:30 AM CDT
In force
6 hr
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Flood severity
None

County Mobile County, AL

The radar

The Mobile radar (KMOB), 16 km from the middle of the area, began a volume at 01:26 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

TimeReportWhereRemark
May 20, 8:50 PM CDTFLASH FLOODNnw Airport And Univers, ALSTREET FLOODING ON AIRPORT BLVD EASTBOUND NEAR AIRPORT AND UNIVERSITY BLVD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 1.4 hours before the alert went out and 142 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-pSkew-T log-p diagram, Slidell Radar S, LA at 00:00Z on 2017-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3071 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 00:00Z on 2017-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
3071 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
745 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

394 
WGUS54 KMOB 210125
FFWMOB
ALC097-210730-
/O.NEW.KMOB.FF.W.0015.170521T0125Z-170521T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
825 PM CDT SAT MAY 20 2017

The National Weather Service in Mobile has issued a

* Flash Flood Warning for...
  Southwestern Mobile County in southwestern Alabama...

* Until 230 AM CDT Sunday

* At 824 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have 
  already fallen and additional heavy rainfall may lead to flash 
  flooding over the warned area.

* Some locations that will experience flooding include...
  Midtown Mobile, Downtown Mobile, Tillmans Corner, Theodore, Grand
  Bay, Mobile Regional Airport and I10 And I65.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3042 8840 3071 8841 3070 8800 3045 8806

$$
1 follow-up statement
304 
WGUS74 KMOB 210257
FFSMOB

Flash Flood Statement
National Weather Service Mobile AL
957 PM CDT SAT MAY 20 2017

ALC097-210730-
/O.CON.KMOB.FF.W.0015.000000T0000Z-170521T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mobile AL-
957 PM CDT SAT MAY 20 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM CDT FOR
SOUTHWESTERN MOBILE COUNTY...

At 850 PM CDT, flooding was reported on the eastbound lane of 
Airport Boulevard near the intersection with University Boulevard.

At 946 PM CDT, Doppler radar indicated that heavier rains were 
moving south and east of the warned area. However, radar estimates 
that 2 to 4 inches of rain with locally higher amounts have fallen 
in the warned area this evening, and flash flooding will continue to 
impact some locations. 

Some locations that will continue to experience flooding include...
Midtown Mobile, Downtown Mobile, Tillmans Corner, Theodore, Grand
Bay, Mobile Regional Airport and I10 And I65.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3042 8840 3071 8841 3070 8800 3045 8806

$$

The office that day

Everything else NWS Mobile, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 7:06 PM CDTAreal Flood AdvisoryMOBMobile3 hr
May 20, 7:19 PM CDTSpecial Weather StatementMOBMobile41 min
May 20, 7:38 PM CDTFlash Flood WarningMOBMobile6 hr
May 20, 7:46 PM CDTSpecial Weather StatementMOBMobile44 min
May 20, 8:09 PM CDTSpecial Weather StatementMOBBaldwin, Mobile51 min
May 20, 8:12 PM CDTSpecial Weather StatementMOBBaldwin48 min
May 20, 8:17 PM CDTSpecial Marine WarningMOB88 min
May 20, 8:21 PM CDTSevere Thunderstorm WarningMOBMobile39 min
May 20, 8:56 PM CDTFlash Flood WatchMOBBaldwin, Escambia, Mobile7 hr
May 20, 9:02 PM CDTFlash Flood WarningMOBBaldwin, Escambia6 hr
May 20, 9:07 PM CDTSpecial Weather StatementMOBBaldwin, Escambia53 min
May 20, 9:23 PM CDTSpecial Marine WarningMOB52 min
May 20, 9:26 PM CDTSpecial Marine WarningMOB2 hr
May 20, 10:21 PM CDTAreal Flood AdvisoryMOBBaldwin, Conecuh, Covington, Escambia3 hr
May 20, 10:25 PM CDTSpecial Weather StatementMOBCovington65 min
May 20, 10:34 PM CDTSpecial Marine WarningMOB116 min
May 20, 10:58 PM CDTSevere Thunderstorm WarningMOBCovington47 min
May 20, 11:14 PM CDTAreal Flood AdvisoryMOBCovington, Crenshaw3 hr
May 20, 11:40 PM CDTSpecial Marine WarningMOB2 hr
May 20, 11:59 PM CDTAreal Flood WarningMOBBaldwin, Clarke, Mobile, Washington12 hr
May 21, 12:18 AM CDTSpecial Marine WarningMOB57 min
May 21, 1:30 AM CDTAreal Flood WarningMOBMobile12 hr
May 21, 1:55 AM CDTSpecial Marine WarningMOB95 min
May 21, 3:21 PM CDTFlash Flood WatchMOBBaldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 6 more47 hr

Nearby

Flash Flood Warnings in Alabama, 2017Every flash flood warning in 2017

Sources

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