Alert archive / Maryland / Flash Flood Warnings in 2009

Flash Flood Warning 31, NWS Baltimore/Washington

August 2, 2009Harford County, Maryland

NWS Baltimore/Washington issued this flash flood warning at Aug 2, 2009, 10:25 AM EDT for Harford County, Maryland. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 2, 2009, 10:25 AM EDT (14:25 UTC)
Expired
Aug 2, 2009, 12:52 PM EDT
In force
2 hr
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Flood severity
None

County Harford County, MD

The radar

The Dover AFB radar (KDOX), 108 km from the middle of the area, began a volume at 14:25 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, 2.4 hours before the alert went out and 115 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, Washington/Dulle, VA at 12:00Z on 2009-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 633 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2009-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 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
633 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
689 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 2, 4:06 AM EDTFlash Flood WatchLWXArlington, Culpeper, Fairfax, King George, Orange, Spotsylvania and 5 more10 hr
Aug 2, 9:51 AM EDTSmall Craft AdvisoryLWX5 hr
Aug 2, 10:19 AM EDTSpecial Marine WarningLWX26 min
Aug 2, 10:52 AM EDTSpecial Marine WarningLWX35 min
Aug 2, 11:33 AM EDTSpecial Marine WarningLWX87 min
Aug 2, 11:48 AM EDTSpecial Marine WarningLWX46 min
Aug 2, 11:52 AM EDTSpecial Marine WarningLWX83 min
Aug 2, 12:23 PM EDTSpecial Marine WarningLWX97 min
Aug 2, 12:36 PM EDTSpecial Marine WarningLWX84 min
Aug 2, 2:55 PM EDTSpecial Marine WarningLWX50 min
Aug 2, 3:13 PM EDTSpecial Marine WarningLWX47 min
Aug 2, 4:47 PM EDTSpecial Marine WarningLWX27 min
Aug 2, 7:05 PM EDTSpecial Marine WarningLWX40 min
Aug 2, 7:49 PM EDTSpecial Marine WarningLWX86 min
Aug 2, 7:12 AM EDTSevere Thunderstorm WarningLWXCarroll, Frederick, Washington67 min

Nearby

Flash Flood Warnings in Maryland, 2009Every flash flood warning in 2009

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.