Alert archive / Maryland / Areal Flood Advisories in 2021

Areal Flood Advisory 182, NWS Philadelphia/Mount Holly

September 23, 2021Kent County, Queen Anne's County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this areal flood advisory at Sep 23, 2021, 9:03 AM EDT for Kent County, Queen Anne's County, Talbot County, Maryland. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Sep 23, 2021, 9:03 AM EDT (13:03 UTC)
Expired: Sep 23, 2021, 12:00 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Kent County, MD, Queen Anne's County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 71 km from the middle of the area, began a volume at 13:05 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 1.1 hours before the alert went out and 99 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: 517 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: -71 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

494 
WGUS81 KPHI 231303
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
903 AM EDT Thu Sep 23 2021

MDC029-035-041-231600-
/O.NEW.KPHI.FA.Y.0182.210923T1303Z-210923T1600Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kent MD-Queen Anne's MD-Talbot MD-
903 AM EDT Thu Sep 23 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Talbot County in eastern Maryland...
  Kent County in northeastern Maryland...
  Central Queen Anne's County in northeastern Maryland...

* Until noon EDT.

* At 903 AM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Minor flooding is ongoing or expected to begin 
  shortly in the advisory area. Up to 2 inches of rain have fallen, 
  with an additional 1 to 2 inches possible.

* Some locations that may experience flooding include...
  Easton, Centerville, Talbot, Chestertown, Centreville, Romancoke, 
  Rock Hall, Trappe, St. Michaels, Church Hill, Oxford, and 
  Betterton.

LAT...LON 3884 7638 3904 7630 3901 7629 3917 7627
      3932 7619 3937 7611 3937 7596 3861 7606
      3868 7621 3876 7622 3871 7627 3875 7630
      3878 7627 3876 7632 3871 7633 3867 7634
      3877 7633 3876 7638

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 23, 8:08 AM EDT	Special Weather Statement	PHI	Kent, Queen Anne's, Talbot	52 min
Sep 23, 9:31 AM EDT	Special Weather Statement	PHI	Kent, Queen Anne's, Talbot	59 min
Sep 23, 9:46 AM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	44 min
Sep 23, 9:49 AM EDT	Flash Flood Warning	PHI	Kent, Queen Anne's, Talbot	4 hr
Sep 23, 10:35 AM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's	40 min
Sep 23, 10:55 AM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	3 hr

Nearby

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.