Alert archive / Maryland / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 42, NWS Baltimore/Washington

May 13, 2002Frederick County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at May 13, 2002, 7:20 PM EDT for Frederick County, Maryland. It was in force for 40 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 13, 2002, 7:20 PM EDT (23:20 UTC)
Expired: May 13, 2002, 8:00 PM EDT
In force: 40 min
Issued by: NWS Baltimore/Washington
Area: Counties, with a storm outline in the text

County Frederick County, MD

The radar

The Sterling radar (KLWX), 56 km from the middle of the area, began a volume at 23:23 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.

What was reported inside it

Time	Report	Where	Remark
May 13, 7:30 PM EDT	Thunderstorm Wind	West Portion, MD	A couple of trees were downed on Gatlin Road.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.3 hours before the alert went out and 58 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: 313 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 1186 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 117 m²/s²
0-3 km storm-relative helicity: 127 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this severe thunderstorm warning went out at May 13, 7:10 PM EDT, 10 minutes earlier.

Area forecast discussion, May 13, 7:10 PM EDT, 10 minutes before

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In the hours before

Local storm report, May 13, 5:45 PM EDT, 1 hour 35 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
545 PM EDT MON MAY 13 2002

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0315 PM    1 SW ROCKVILLE            MD   POSSIBLE TORNADO
05/13/02   MONTGOMERY                     REPORTED BY FORMER NWS
                                          EMPLOYEE

0325 PM    ELLICOTT CITY             MD   WIND DAMAGE
05/13/02   HOWARD                         TREES DOWN

0340 PM    NW BALTIMORE CITY         MD   1.00 INCH HAIL
05/13/02   BALTIMORE

0345 PM    N BALTIMORE CITY          MD   .88 INCH HAIL
05/13/02   BALTIMORE                      COVERED GROUND TO A DEPTH
                                          OF 3 INCHES

0350 PM    WHITE MARSH               MD   1.75 INCH HAIL
05/13/02   BALTIMORE                      NEAR RT 40 AND EBENEZER RD

0405 PM    ABINGDON                  MD   .75 INCH HAIL
05/13/02   HARFORD

0400 PM    EDGEWOOD                  MD   1.00 INCH HAIL
05/13/02   HARFORD

0345 PM    COUNTY WIDE               MD   WIND DAMAGE
05/13/02   BALTIMORE                      TREES AND POWER LINES DOWN
                                          IN NUMEROUS LOCATIONS
                                          ACROSS SOUTHERN PORTION OF
                                          THE COUNTY

0410 PM    SPESUTIE ISLAND           MD   55 MPH TSTM WIND GUST
05/13/02   HOWARD                         MEASURED AT INSTRUMENTED
                                          SITE AT ABERDEEN PROVING
                                          GROUND

SMZ

Local storm report, May 13, 5:45 PM EDT, 1 hour 35 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTION LAST REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
545 PM EDT MON MAY 13 2002

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0315 PM    1 SW ROCKVILLE            MD   POSSIBLE TORNADO
05/13/02   MONTGOMERY                     REPORTED BY FORMER NWS
                                          EMPLOYEE

0325 PM    ELLICOTT CITY             MD   WIND DAMAGE
05/13/02   HOWARD                         TREES DOWN

0340 PM    NW BALTIMORE CITY         MD   1.00 INCH HAIL
05/13/02   BALTIMORE

0345 PM    N BALTIMORE CITY          MD   .88 INCH HAIL
05/13/02   BALTIMORE                      COVERED GROUND TO A DEPTH
                                          OF 3 INCHES

0350 PM    WHITE MARSH               MD   1.75 INCH HAIL
05/13/02   BALTIMORE                      NEAR RT 40 AND EBENEZER RD

0405 PM    ABINGDON                  MD   .75 INCH HAIL
05/13/02   HARFORD

0400 PM    EDGEWOOD                  MD   1.00 INCH HAIL
05/13/02   HARFORD

0345 PM    COUNTY WIDE               MD   WIND DAMAGE
05/13/02   BALTIMORE                      TREES AND POWER LINES DOWN
                                          IN NUMEROUS LOCATIONS
                                          ACROSS SOUTHERN PORTION OF
                                          THE COUNTY

0410 PM    SPESUTIE ISLAND           MD   55 MPH TSTM WIND GUST
05/13/02   HARFORD                        MEASURED AT INSTRUMENTED                                           SITE AT
                                          ABERDEEN PROVING GROUND

SMZ

Local storm report, May 13, 6:20 PM EDT, 1 hour before

PRELIMINARY LOCAL STORM REPORT...CORRECTION LAST REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
545 PM EDT MON MAY 13 2002

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0315 PM    1 SW ROCKVILLE            MD   POSSIBLE TORNADO
05/13/02   MONTGOMERY                     REPORTED BY FORMER NWS
                                          EMPLOYEE

0325 PM    ELLICOTT CITY             MD   WIND DAMAGE
05/13/02   HOWARD                         TREES DOWN

0340 PM    NW BALTIMORE CITY         MD   1.00 INCH HAIL
05/13/02   BALTIMORE

0345 PM    N BALTIMORE CITY          MD   .88 INCH HAIL
05/13/02   BALTIMORE                      COVERED GROUND TO A DEPTH
                                          OF 3 INCHES

0350 PM    WHITE MARSH               MD   1.75 INCH HAIL
05/13/02   BALTIMORE                      NEAR RT 40 AND EBENEZER RD

0405 PM    ABINGDON                  MD   .75 INCH HAIL
05/13/02   HARFORD

0400 PM    EDGEWOOD                  MD   1.00 INCH HAIL
05/13/02   HARFORD

0345 PM    COUNTY WIDE               MD   WIND DAMAGE
05/13/02   BALTIMORE                      TREES AND POWER LINES DOWN
                                          IN NUMEROUS LOCATIONS
                                          ACROSS SOUTHERN PORTION OF
                                          THE COUNTY

0410 PM    SPESUTIE ISLAND           MD   55 MPH TSTM WIND GUST
05/13/02   HARFORD                        MEASURED AT INSTRUMENTED                                           SITE AT
                                          ABERDEEN PROVING GROUND

SMZ

Local storm report, May 13, 6:27 PM EDT, 53 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTION LAST REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
545 PM EDT MON MAY 13 2002

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0315 PM    1 SW ROCKVILLE            MD   POSSIBLE TORNADO
05/13/02   MONTGOMERY                     REPORTED BY FORMER NWS
                                          EMPLOYEE

0325 PM    ELLICOTT CITY             MD   WIND DAMAGE
05/13/02   HOWARD                         TREES DOWN

0340 PM    NW BALTIMORE CITY         MD   1.00 INCH HAIL
05/13/02   BALTIMORE

0345 PM    N BALTIMORE CITY          MD   .88 INCH HAIL
05/13/02   BALTIMORE                      COVERED GROUND TO A DEPTH
                                          OF 3 INCHES

0350 PM    WHITE MARSH               MD   1.75 INCH HAIL
05/13/02   BALTIMORE                      NEAR RT 40 AND EBENEZER RD

0405 PM    ABINGDON                  MD   .75 INCH HAIL
05/13/02   HARFORD

0400 PM    EDGEWOOD                  MD   1.00 INCH HAIL
05/13/02   HARFORD

0345 PM    COUNTY WIDE               MD   WIND DAMAGE
05/13/02   BALTIMORE                      TREES AND POWER LINES DOWN
                                          IN NUMEROUS LOCATIONS
                                          ACROSS SOUTHERN PORTION OF
                                          THE COUNTY

0410 PM    SPESUTIE ISLAND           MD   55 MPH TSTM WIND GUST
05/13/02   HARFORD                        MEASURED AT INSTRUMENTED
                                          SITE AT ABERDEEN PROVING
                                          GROUND

SMZ

Local storm report, May 13, 6:35 PM EDT, 45 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTION LAST REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
545 PM EDT MON MAY 13 2002

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0315 PM    1 SW ROCKVILLE            MD   POSSIBLE TORNADO
05/13/02   MONTGOMERY                     REPORTED BY FORMER NWS
                                          EMPLOYEE

0325 PM    ELLICOTT CITY             MD   WIND DAMAGE
05/13/02   HOWARD                         TREES DOWN

0340 PM    NW BALTIMORE CITY         MD   1.00 INCH HAIL
05/13/02   BALTIMORE

0345 PM    N BALTIMORE CITY          MD   .88 INCH HAIL
05/13/02   BALTIMORE                      COVERED GROUND TO A DEPTH
                                          OF 3 INCHES

0350 PM    WHITE MARSH               MD   1.75 INCH HAIL
05/13/02   BALTIMORE                      NEAR RT 40 AND EBENEZER RD

0405 PM    ABINGDON                  MD   .75 INCH HAIL
05/13/02   HARFORD

0400 PM    EDGEWOOD                  MD   1.00 INCH HAIL
05/13/02   HARFORD

0345 PM    COUNTY WIDE               MD   WIND DAMAGE
05/13/02   BALTIMORE                      TREES AND POWER LINES DOWN
                                          IN NUMEROUS LOCATIONS
                                          ACROSS SOUTHERN PORTION OF
                                          THE COUNTY

0410 PM    SPESUTIE ISLAND           MD   47 MPH TSTM WIND GUST
05/13/02   HARFORD                        MEASURED AT INSTRUMENTED
                                          SITE AT ABERDEEN PROVING
                                          GROUND

SMZ

Special weather statement, May 13, 6:46 PM EDT, 34 minutes before

MDZ002>004-VAZ027>031-042-WVZ050>053-055-140015-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
646 PM EDT MON MAY 13 2002

...SHOWERS AND THUNDERSTORMS WITH STRONG GUSTY WINDS MOVING THROUGH
EASTERN WEST VIRGINIA...

AT 645 PM DOPPLER WEATHER RADAR INDICATED A LINE OF SHOWERS AND
THUNDERSTORMS EXTENDING FROM ALLEGANY COUNTY THROUGH HAMPSHIRE
COUNTY TO WESTERN SHENANDOAH COUNTY.

THE SHOWERS AND THUNDERSTORMS ARE MOVING EAST-NORTHEAST AT 50 MPH
AND WILL AFFECT PORTIONS OF WESTERN MARYLAND...NORTHWEST VIRGINIA
AND THE EASTERN PANHANDLE OF WEST VIRGINIA DURING THE NEXT HOUR.

HEAVY RAIN AND WIND GUSTS TO 50 MPH ARE POSSIBLE IN THESE SHOWERS
AND THUNDERSTORMS.

WALSTON

The office that day

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

Issued	Product	Office	Counties	Lasted
May 12, 8:58 PM EDT	Severe Thunderstorm Warning	LWX	Arlington, Fairfax	47 min
May 13, 12:51 PM EDT	Severe Thunderstorm Warning	LWX	Rockingham, City of Harrisonburg	39 min
May 13, 12:59 PM EDT	Severe Thunderstorm Warning	LWX	Page	31 min
May 13, 1:12 PM EDT	Severe Thunderstorm Warning	LWX	Madison, Page, Rappahannock, Shenandoah, Warren	48 min
May 13, 1:22 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick	23 min
May 13, 1:47 PM EDT	Severe Thunderstorm Warning	LWX	Loudoun	43 min
May 13, 2:21 PM EDT	Severe Thunderstorm Warning	LWX	Fairfax, Loudoun, Prince William	39 min
May 13, 3:30 PM EDT	Special Marine Warning	LWX		2 hr
May 13, 3:30 PM EDT	Special Marine Warning	LWX		2 hr
May 13, 3:32 PM EDT	Special Marine Warning	LWX		43 min
May 13, 4:06 PM EDT	Special Marine Warning	LWX		39 min
May 13, 7:02 PM EDT	Severe Thunderstorm Warning	LWX	Clarke, Frederick, City of Winchester	43 min
May 13, 3:11 PM EDT	Tornado Warning	LWX	Montgomery	34 min
May 13, 3:14 PM EDT	Tornado Warning	LWX	Howard	31 min
May 13, 3:21 PM EDT	Tornado Warning	LWX	Baltimore, City of Baltimore	24 min
May 13, 3:46 PM EDT	Tornado Warning	LWX	Baltimore, Harford, City of Baltimore	29 min
May 13, 4:36 PM EDT	Severe Thunderstorm Warning	LWX	Harford	24 min
May 13, 7:57 PM EDT	Severe Thunderstorm Warning	LWX	Saint Mary's	33 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2002 Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.