Alert archive / Maryland / Tornado Warnings in 2010

Tornado Warning 21, NWS Baltimore/Washington

September 30, 2010Calvert County, Saint Mary's County, Maryland

NWS Baltimore/Washington issued this tornado warning at Sep 30, 2010, 6:17 AM EDT for Calvert County, Saint Mary's County, Maryland. It was in force for 28 min. 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
Sep 30, 2010, 6:17 AM EDT (10:17 UTC)
Expired
Sep 30, 2010, 6:45 AM EDT
In force
28 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon

Counties Calvert County, MD, Saint Mary's County, MD

The radar

The Dover AFB radar (KDOX), 102 km from the middle of the area, began a volume at 10:18 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
Sep 30, 6:17 AM EDTTSTM WND DMGPark Pines, MDNUMEROUS TREES DOWN ALONG ROUTE 235.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 30, 4:55 AM EDTTornado WatchSPC8 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 10.3 hours before the alert went out and 100 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, Wallops Is Stn, VA at 00:00Z on 2010-09-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 52 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, Wallops Is Stn, VA at 00:00Z on 2010-09-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 177 square meters per square second.19395878Sfc1 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
52 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
559 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
177 m²/s²
0-3 km storm-relative helicity
218 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

306 
WFUS51 KLWX 301017
TORLWX
MDC009-037-301100-
/O.NEW.KLWX.TO.W.0021.100930T1017Z-100930T1100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
617 AM EDT THU SEP 30 2010

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN CALVERT COUNTY IN SOUTHERN MARYLAND...
  EASTERN ST. MARYS COUNTY IN SOUTHERN MARYLAND...

* UNTIL 700 AM EDT

* AT 616 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR SAINT MARYS
  CITY...MOVING NORTH AT 40 MPH.

* LOCATIONS IMPACTED INCLUDE...
  PATUXENT RIVER NAS...
  CALIFORNIA...
  CUCKOLD CREEK...
  TOWN CREEK...
  LUSBY...
  SAINT LEONARD CREEK...
  GREENWELL STATE PARK...
  CALVERT CLIFFS...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

THE TORNADO MAY BE WRAPPED IN RAIN AND HARD TO SEE. DO NOT WAIT TO
SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3817 7638 3818 7648 3840 7660 3853 7654
      3855 7651 3848 7648 3839 7637 3836 7638
      3833 7640 3830 7636 3827 7638 3825 7638
      3820 7635
TIME...MOT...LOC 1017Z 174DEG 36KT 3822 7642

$$

GMS
3 follow-up statements
642 
WWUS51 KLWX 301024
SVSLWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
624 AM EDT THU SEP 30 2010

MDC009-037-301100-
/O.CON.KLWX.TO.W.0021.000000T0000Z-100930T1100Z/
CALVERT MD-ST. MARYS MD-
624 AM EDT THU SEP 30 2010

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 AM EDT FOR EAST
CENTRAL ST. MARYS AND SOUTHEASTERN CALVERT COUNTIES...

AT 623 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
TORNADO WAS LOCATED NEAR PATUXENT RIVER NAS...OR NEAR LEXINGTON
PARK...MOVING NORTH AT 40 MPH.

LOCATIONS IMPACTED INCLUDE...
  DRUM POINT...
  DOWELL...
  COVE POINT...
  CUCKOLD CREEK...
  LUSBY...
  SAINT LEONARD CREEK...
  GREENWELL STATE PARK...
  CALVERT CLIFFS...
  CALVERT BEACH...
  LONG BEACH...
  BROOMES ISLAND...
  SAINT LEONARD...
  PORT REPUBLIC...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

THIS TORNADO MAY BE WRAPPED IN RAIN AND HARD TO SEE. DO NOT WAIT TO
SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3825 7638 3823 7640 3825 7646 3843 7659
      3853 7654 3855 7651 3848 7648 3839 7637
      3836 7638 3833 7640 3830 7636 3827 7638
TIME...MOT...LOC 1024Z 178DEG 35KT 3829 7642

$$

GMS
446 
WWUS51 KLWX 301034
SVSLWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
634 AM EDT THU SEP 30 2010

MDC037-301044-
/O.CAN.KLWX.TO.W.0021.000000T0000Z-100930T1100Z/
ST. MARYS MD-
634 AM EDT THU SEP 30 2010

...THE TORNADO WARNING IS CANCELLED FOR EAST CENTRAL ST. MARYS
COUNTY...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE WARNED
AREA. THUS THE TORNADO WARNING HAS BEEN CANCELLED.

LAT...LON 3836 7638 3831 7642 3832 7644 3831 7646
      3838 7649 3841 7652 3849 7656 3853 7654
      3855 7651 3848 7648 3839 7637
TIME...MOT...LOC 1034Z 178DEG 35KT 3838 7642

$$

MDC009-301100-
/O.CON.KLWX.TO.W.0021.000000T0000Z-100930T1100Z/
CALVERT MD-
634 AM EDT THU SEP 30 2010

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 AM EDT FOR
SOUTHEASTERN CALVERT COUNTY...

AT 633 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
TORNADO WAS LOCATED NEAR LUSBY...OR NEAR CUCKOLD CREEK...MOVING NORTH
AT 40 MPH.

LOCATIONS IMPACTED INCLUDE...
  CALVERT CLIFFS...
  LUSBY...
  CALVERT BEACH...
  LONG BEACH...
  SAINT LEONARD...
  PORT REPUBLIC...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

THIS TORNADO MAY BE WRAPPED IN RAIN AND HARD TO SEE. DO NOT WAIT TO
SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3836 7638 3831 7642 3832 7644 3831 7646
      3838 7649 3841 7652 3849 7656 3853 7654
      3855 7651 3848 7648 3839 7637
TIME...MOT...LOC 1034Z 178DEG 35KT 3838 7642

$$

GMS
250 
WWUS51 KLWX 301045
SVSLWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
645 AM EDT THU SEP 30 2010

MDC009-301055-
/O.CAN.KLWX.TO.W.0021.000000T0000Z-100930T1100Z/
CALVERT MD-
645 AM EDT THU SEP 30 2010

...THE TORNADO WARNING IS CANCELLED FOR SOUTHEASTERN CALVERT
COUNTY...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE WARNED
AREA. THUS THE TORNADO WARNING HAS BEEN CANCELLED.

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. 

LAT...LON 3836 7638 3831 7642 3832 7644 3831 7646
      3838 7649 3841 7652 3849 7656 3853 7654
      3855 7651 3848 7648 3839 7637
TIME...MOT...LOC 1045Z 178DEG 35KT 3849 7642

$$

GMS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 29, 8:48 PM EDTCoastal Flood AdvisoryLWXAnne Arundel, Baltimore, Calvert, Charles, Prince George's, Saint Mary's and 1 more25 hr
Sep 30, 3:57 AM EDTTornado WarningLWXAnne Arundel, Calvert, Saint Mary's33 min
Sep 30, 4:57 AM EDTFlash Flood WarningLWXAnne Arundel, Calvert, Charles, Montgomery, Prince George's, Saint Mary's6 hr
Sep 30, 6:08 AM EDTSpecial Weather StatementLWXSaint Mary's52 min
Sep 30, 6:39 AM EDTFlash Flood WarningLWXAnne Arundel, Baltimore, Carroll, Frederick, Harford, Howard and 2 more6 hr
Sep 30, 7:32 AM EDTSpecial Weather StatementLWXSaint Mary's43 min
Sep 30, 8:09 AM EDTCoastal Flood WarningLWXAnne Arundel, Baltimore, Calvert, Charles, Prince George's, Saint Mary's and 1 more21 hr
Sep 30, 8:45 AM EDTSevere Thunderstorm WarningLWXHarford45 min
Sep 30, 8:58 AM EDTTornado WarningLWXCalvert, Saint Mary's47 min
Sep 30, 9:28 AM EDTTornado WarningLWXAnne Arundel47 min
Sep 30, 9:49 AM EDTTornado WarningLWXAnne Arundel, Calvert26 min
Sep 30, 9:51 AM EDTRiver Flood WarningLWXMontgomery24 hr
Sep 30, 10:29 AM EDTFlash Flood WarningLWXFrederick, Washington4 hr
Sep 30, 10:38 AM EDTFlash Flood WarningLWXAnne Arundel, Calvert, Charles, Howard, Montgomery, Prince George's and 1 more6 hr
Sep 30, 10:49 AM EDTSevere Thunderstorm WarningLWXHoward, Montgomery, Prince George's26 min
Sep 30, 11:12 AM EDTRiver Flood WarningLWXFrederick5 hr
Sep 30, 11:12 AM EDTRiver Flood WarningLWXFrederick18 hr
Sep 30, 11:12 AM EDTRiver Flood WarningLWXWashington18 hr
Sep 30, 12:22 PM EDTFlash Flood WarningLWXAnne Arundel, Baltimore, Carroll, Frederick, Harford, Howard and 2 more6 hr
Sep 30, 4:30 PM EDTFlash Flood WarningLWXAnne Arundel, Calvert, Saint Mary's6 hr
Sep 30, 4:40 PM EDTFlash Flood WarningLWXCarroll, Frederick, Howard, Montgomery, Washington11 hr
Sep 30, 6:13 PM EDTFlash Flood WarningLWXAnne Arundel, Baltimore, Calvert, Carroll, Charles, Harford and 5 more6 hr

Nearby

Tornado Warnings in Maryland, 2010Every tornado warning in 2010Tornadoes in 2010

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.