Alert archive / Florida / Flash Flood Warnings in 2020

Flash Flood Warning 24, NWS Mobile, AL

September 15, 2020Okaloosa County, Santa Rosa County, Florida

NWS Mobile, AL issued this flash flood warning at Sep 15, 2020, 4:36 PM CDT for Okaloosa County, Santa Rosa County, Florida. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 15, 2020, 4:36 PM CDT (21:36 UTC)
Expired
Sep 15, 2020, 11:30 PM CDT
In force
7 hr
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Flood severity
None

Counties Okaloosa County, FL, Santa Rosa County, FL

The radar

The Eglin Afb radar (KEVX), 76 km from the middle of the area, began a volume at 21:36 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 9.6 hours before the alert went out and 232 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, Tallahassee Rgnl, FL at 12:00Z on 2020-09-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 64 joules per kilogram.LCLLFCEL10008507005003002001001 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, Tallahassee Rgnl, FL at 12:00Z on 2020-09-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 132 square meters per square second.1939Sfc1 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
64 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
1002 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
132 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

475 
WGUS54 KMOB 152136
FFWMOB
FLC091-113-160430-
/O.NEW.KMOB.FF.W.0024.200915T2136Z-200916T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
436 PM CDT Tue Sep 15 2020

The National Weather Service in Mobile has issued a

* Flash Flood Warning for...
  Okaloosa County in northwestern Florida...
  Southeastern Santa Rosa County in northwestern Florida...

* Until 1130 PM CDT Tuesday.

* At 434 PM CDT, Doppler radar and automated rain gauges indicated 
  heavy rain falling across the warned area. Between 2 and 4 inches 
  of rain have fallen. Flash flooding is already occurring.

  HAZARD...Flash flooding caused by heavy rain associated with
           Hurricane Sally.

  SOURCE...Doppler radar and automated gauges.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Wright, Fort Walton Beach, Crestview, Niceville, Destin, Eglin 
  AFB, Valparaiso, Mary Esther, Ocean City, Lake Lorraine, Baker, 
  Shalimar, Laurel Hill, Cinco Bayou, Milligan, Galliver, Holt, 
  Kellys Mill, Silver Springs and Longwood.

Additional rainfall amounts of 5 to 10 inches are possible in the 
warned area through this evening. Potential rainfall amounts of 18 
to 22 inches are possible through Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other low lying 
spots.

Please report flooding to your local law enforcement agency when you 
can do so safely.

&&

LAT...LON 3055 8691 3082 8692 3099 8639 3037 8639
      3039 8664 3037 8685

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

JFP

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 15, 3:35 PM CDTFlash Flood WarningMOBEscambia, Santa Rosa8 hr
Sep 15, 5:49 PM CDTFlash Flood WarningMOBEscambia, Santa Rosa5 hr

Nearby

Flash Flood Warnings in Florida, 2020Every flash flood warning in 2020

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.