Alert archive / Delaware / Areal Flood Advisories in 2021

Areal Flood Advisory 53, NWS Philadelphia/Mount Holly

July 8, 2021Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 8, 2021, 10:19 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 8, 2021, 10:19 PM EDT (02:19 UTC)
Expired: Jul 9, 2021, 3:29 AM EDT
In force: 5 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Kent County, DE, Sussex County, DE, Caroline County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 33 km from the middle of the area, began a volume at 02:23 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.3 hours before the alert went out and 109 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: 440 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 675 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 336 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

646 
WGUS81 KPHI 090219
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
1019 PM EDT Thu Jul 8 2021

DEC001-005-MDC011-041-091000-
/O.NEW.KPHI.FA.Y.0053.210709T0219Z-210709T1000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-Caroline MD-Talbot MD-
1019 PM EDT Thu Jul 8 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Kent County in central Delaware...
  Sussex County in southern Delaware...
  Caroline County in eastern Maryland...
  Talbot County in eastern Maryland...

* Until 600 AM EDT Friday.

* At 1019 PM EDT, Doppler radar indicated that areas of heavy rain 
  were continuing to move into the area. Minor flooding is ongoing 
  or expected to begin shortly. Between 0.5 and 1 inch of rain has 
  fallen with another 2 to 3 inches possible.

* Some locations that may experience flooding include...
  Dover, Easton, Georgetown, Smyrna, Milford, Seaford, Denton, 
  Millsboro, Laurel, Harrington, Camden, and Clayton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3875 7634 3879 7619 3894 7610 3892 7595
      3914 7575 3930 7576 3939 7550 3924 7533
      3915 7538 3894 7528 3882 7506 3845 7503
      3846 7569 3869 7576 3870 7590 3857 7603
      3876 7623 3867 7634 3869 7635

$$

Iovino

2 follow-up statements

490 
WGUS81 KPHI 090633
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
233 AM EDT Fri Jul 9 2021

MDC011-041-090643-
/O.CAN.KPHI.FA.Y.0053.000000T0000Z-210709T1000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Caroline MD-Talbot MD-
233 AM EDT Fri Jul 9 2021

...FLOOD ADVISORY IS CANCELLED FOR CAROLINE AND TALBOT COUNTIES...

Flooding is no longer expected to pose a threat. Please continue to 
heed any remaining road closures.


LAT...LON 3930 7576 3929 7567 3931 7562 3931 7558
      3935 7555 3936 7552 3937 7551 3938 7552
      3939 7550 3924 7533 3915 7538 3894 7528
      3882 7506 3845 7503 3846 7569

$$

DEC001-005-091000-
/O.CON.KPHI.FA.Y.0053.000000T0000Z-210709T1000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-
233 AM EDT Fri Jul 9 2021

...FLOOD ADVISORY REMAINS IN EFFECT UNTIL 6 AM EDT EARLY THIS 
MORNING FOR KENT AND SUSSEX COUNTIES...

At 233 AM EDT, Doppler radar indicated that the heavy rain was 
continuing to move out of Sussex County and Kent County. However, 
some lingering minor flooding is likely in the advisory area. 
Between 1 and 3 inches of rain have fallen.

Some locations that might be experiencing flooding include...
  Dover, Georgetown, Smyrna, Milford, Seaford, Millsboro, Laurel, 
  Harrington, Camden, Clayton, Lewes, and Milton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3930 7576 3929 7567 3931 7562 3931 7558
      3935 7555 3936 7552 3937 7551 3938 7552
      3939 7550 3924 7533 3915 7538 3894 7528
      3882 7506 3845 7503 3846 7569

$$

Iovino

872 
WGUS81 KPHI 090729
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
329 AM EDT Fri Jul 9 2021

DEC001-005-090739-
/O.CAN.KPHI.FA.Y.0053.000000T0000Z-210709T1000Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent DE-Sussex DE-
329 AM EDT Fri Jul 9 2021

...FLOOD ADVISORY IS CANCELLED FOR KENT AND SUSSEX COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3930 7576 3929 7567 3931 7562 3931 7558
      3935 7555 3936 7552 3937 7551 3938 7552
      3939 7550 3924 7533 3915 7538 3894 7528
      3882 7506 3845 7503 3846 7569

$$

Iovino

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 8, 11:37 PM EDT	Tornado Warning	PHI	Sussex	23 min
Jul 8, 11:59 PM EDT	Tornado Warning	PHI	Sussex	12 min
Jul 9, 12:04 AM EDT	Tornado Warning	PHI	Sussex	26 min
Jul 9, 12:11 AM EDT	Tornado Warning	PHI	Sussex	35 min
Jul 9, 12:28 AM EDT	Tornado Warning	PHI	Sussex	17 min
Jul 9, 4:54 PM EDT	Special Weather Statement	PHI	New Castle	66 min
Jul 9, 5:17 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	43 min
Jul 9, 6:19 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	41 min
Jul 9, 6:50 PM EDT	Areal Flood Advisory	PHI	New Castle	2 hr
Jul 9, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	63 min
Jul 9, 4:52 PM EDT	Special Weather Statement	PHI	Queen Anne's, Talbot	53 min
Jul 9, 5:26 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	49 min

Nearby

Areal Flood Advisories in Delaware, 2021 Areal Flood Advisories in Maryland, 2021 Every areal flood advisory in 2021

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.