Alert archive / Maryland / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 103, NWS Baltimore/Washington

July 5, 2001Carroll County, Frederick County, Howard County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Jul 5, 2001, 6:21 PM EDT for Carroll County, Frederick County, Howard County, Maryland. It was in force for 39 min. 3 reports 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: Jul 5, 2001, 6:21 PM EDT (22:21 UTC)
Expired: Jul 5, 2001, 7:00 PM EDT
In force: 39 min
Issued by: NWS Baltimore/Washington
Area: Whole counties

Counties Carroll County, MD, Frederick County, MD, Howard County, MD

The radar

The Sterling radar (KLWX), 60 km from the middle of the area, began a volume at 22:23 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
Jul 5, 6:21 PM EDT	Thunderstorm Wind	Ridgeville, MD	Trees and wires were downed onto Woodville Road.
Jul 5, 6:45 PM EDT	Thunderstorm Wind	Sykesville, MD	Several wires were downed.
Jul 5, 6:50 PM EDT	Thunderstorm Wind	West Friendship, MD	Trees were downed onto Gaither and Driver 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, 10.4 hours before the alert went out and 59 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: 9 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 1085 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Jul 5, 2:35 PM EDT, 3 hours 46 minutes earlier.

Area forecast discussion, Jul 5, 2:35 PM EDT, 3 hours 46 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
235 PM EDT THU JUL 5 2001

PATTERN ACRS THE COUNTRY WILL BE DOMINATED BY AN UPR LVL TROF OVR
THE ERN U.S. AND UPR LVL RDG OVR THE ROCKIES AND PLAIN STATES. BY
SAT...THE UPR LVL TROF WILL BEGIN TO LIFT OUT AS THE CUTOFF LOW OVR
QUEBEC BEGINS TO MOVE NE. THIS WILL RESULT IN RISING HGTS OVR THE
AREA BY SAT. HOWEVER...BY SUN...ANOTHER PIECE OF ENERGY DROPS INTO
THE LONGWAVE TROF POSITION ALG THE E COAST...REINFORCING THE TROF.

SFC CDFNT WILL MOVE THRU THE AREA THIS EVE. DON'T EXPECT WIDESPREAD
CONVECTION ALG OR AHD OF THE CDFNT. SOUNDINGS SHOW A WEAK CAP OVR
THE AREA. WINDS WILL NOT BE BACKING MUCH AHD OF THE CDFNT SO
CONVERGENCE IS WEAK.  IN ADDITION...ALL THE DEEP MOISTURE HAS BEEN
SWEPT E OF THE AREA WITH THE SFC TROF LEAVING ONLY SOME RESIDUAL
SHALLOW MOISTURE OVR THE AREA. ALSO...WESTERLY FLOW AHD OF THE CDFNT
WILL RESULT IN DOWNSLOPING WHICH WILL TEND TO SUPPRESS CONVECTION.
HOWEVER...MODIFIED SOUNDING SHOWS A CAPE OF 1300 THIS EVE WITH LIS
AROUND MINUS 4. IN ADDITION...THE 12Z ETA AND NGM BOTH SHOW SOME QPF
OVR THE AREA. WILL LEAVE 30 POPS IN THE FCST UNTIL MIDNIGHT THEN P/C.

SFC HIGH PRES BUILDS INTO THE AREA FRI AND FRI NIGHT WITH A COOL AND
DRY AIR MASS. GOING WITH SUNNY SKIES FRI AND CLR FRI NIGHT.

SFC HIGH MOVES OFF THE CST SAT AND RETURN S FLOW DEVELOPS BRINGING
SOME MOISTURE BACK INTO THE AREA. IN ADDITION...AS HGTS START TO
RISE OVR THE AREA...WHATS LEFT OF THE FNT TO OUR S WILL MOVE BACK N
AS A WEAK WMFNT. ETA DEVELOPS SOME UVVS OVR THE AREA LATE SAT IN
ASSOCIATION WITH THE RETURN FLOW/WMFNT. THE AVN KEEPS THE UVVS NW OF
THE AREA. THINK THE ETA MAY BE OVERDOING THE UVVS AND MOISTURE SO
RIGHT NOW WILL ONLY HAVE HIDDEN 20 POPS IN FOR SAT AND HOLD OFF ON
MENTIONING ANY SHRAS/TSRAS UNTIL SAT NIGHT.

NGM AND AVN MOS NUMBERS ARE CLOSE THE 1ST 3 PDS. HOWEVER...THE MOS
HAS BEEN RUNNING TOO WARM LATELY WHEN WE GET A COOL DRY AIR MASS
INTO THE AREA. WILL UNDERCUT MOS TEMPS A COUPLE DEGREES ON FRI.  NGM
MOS IS WARMER THAN THE AVN MOS FOR SAT. WENT WITH A COMPROMISE
BETWEEN THE TWO SETS OF NUMBERS SAT.

FOR THE EXTENDED...
THE AVN HAS A CDFNT MOVING THRU THE AREA ON SUN AS THE NEXT
SHORTWAVE DROPS INTO THE TROF POSITION. WILL HAVE CHC POPS SUN FOR
SHRA/TSRA. HIGH PRES BUILDS INTO THE AREA MON/TUE WITH DRIER AIR
MASS.

FCSTID = 15 / DMW

DCA   63  81  63  87 /  30   0   0  20
BWI   58  80  56  87 /  30   0   0  20
MRB   54  80  52  87 /  30   0   0  20
IAD   54  80  52  87 /  30   0   0  20
CHO   58  81  59  87 /  30   0   0  20
HGR   52  79  51  86 /  30   0   0  20
NHK   6U4  81  63  87 /  30   0   0  20
W99   48  78  47  85 /  30   0   0  20

.LWX...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.

In the hours before

Local storm report, Jul 5, 6:07 PM EDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
607 PM EDT THU JUL 5 2001

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

0352 PM    GERMANTOWN                MD   1.00 INCH HAIL
07/05/01   MONTGOMERY                     REPORTED BY SPOTTERS.

0445 PM    WESTERN SECTION           VA   WIND DAMAGE
07/05/01   STAFFORD                       TREES DOWN ACROSS
                                          GARRISONVILLE ROAD AND ROCK
                                          HILL CHURCH ROAD. REPORTED
                                          BY LAW ENFORCEMENT.

0520 PM    SUITLAND                  MD  o .75 INCH HAIL
07/05/01   PRINCE GEORGES                 PEA TO DIME SIZED HAIL
                                          AT WORLD WEATHER BUILDING.
                                          REPORTED BY EMPLOYEE.

HTS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 3:48 PM EDT	Severe Thunderstorm Warning	LWX	Montgomery	27 min
Jul 5, 5:20 PM EDT	Severe Thunderstorm Warning	LWX	Prince George's	40 min
Jul 5, 5:32 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel	28 min
Jul 5, 6:45 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, City of Baltimore	60 min
Jul 5, 6:57 PM EDT	Tornado Warning	LWX	Baltimore, City of Baltimore	33 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2001 Every severe thunderstorm warning in 2001

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.