Alert archive / Iowa / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 336, NWS Omaha, NE

July 3, 2001Mills County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Jul 3, 2001, 6:56 AM CDT for Mills County, Iowa. It was in force for 34 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: Jul 3, 2001, 6:56 AM CDT (11:56 UTC)
Expired: Jul 3, 2001, 7:30 AM CDT
In force: 34 min
Issued by: NWS Omaha, NE
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Mills County, IA

The radar

The Omaha radar (KOAX), 70 km from the middle of the area, began a volume at 11:57 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 3, 6:58 AM CDT	Hail 0.75	Glenwood, IA

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

Omaha, NE (KOAX), launched 00:00Z, 11.9 hours before the alert went out and 70 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: 2777 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 1589 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 4.0

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 Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 3, 2:50 AM CDT, 4 hours 6 minutes earlier.

Area forecast discussion, Jul 3, 2:50 AM CDT, 4 hours 6 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA NE
250 AM CDT TUE JUL 3 2001

CONVECTIVE ACTIVITY ACROSS NE AND E CNTRL NEB INTO WRN IA LIKELY TO
PERSIST INTO THE START OF THE MRNG AND THEN WEAKEN AS LOW LEVEL
INFLOW ASSOCIATED WITH LOW LEVEL JET INTO FRONT AND OUTFLOW BOUNDARY
WEAKENS AND SHORTWAVE IN NWLY UPPER FLOW MOVES SEWD OUT OF AREA.
QUESTION THEN BECOMES POTENTIAL FOR ADDITIONAL DEVELOPMENT LATER IN
DAY WITH OUTFLOW BOUNDARIES AND FRON OVER AREA. ALTHOUGH PATTERN
TENDS TO FAVOR NOCTURNAL NATURE OF CONVECTION AS LOW LEVEL JET
INCREASES INFLOW INTO BOUNDARIES...CANNOT COMPLETELY RULE OUT CHANCE
AGAIN LATER TODAY. MAIN POTENTIAL THOUGH AFTER THIS MRNG AGAIN
APPEARS TO BE TONIGHT. HOWEVER OF INTEREST FOR TONIGHT IS THAT ETA
AND NGM IN PARTICULIAR INDICATE LESS OF A LOW LEVEL JET AND LOW
LEVEL WAA INTO BOUNDARY THAN TONIGHT WHICH COULD SERVE TO SOME
DECREASE NATURE OF CONVECTION. TRENDS ON THE FOURTH INDICATE
ADVECTION OF SOMEWHAT COOLER AND DRIER AIR ON N AND NELY LOWER LEVEL
FLOW WITH MINIMAL CHANCE FOR TSTMS DURING DAY. IF ETA AND MESO ETA
CORRECT COULD SEE ANOTHER CHC FOR TSTMS AGAIN LATER WED NIGHT AS LOW
LEVEL POSITIVE THETA E ADVECTION INCREASES AGAIN OVER BOUNDARY AND
ACTIVITY LIKELY DEVELOPING OVER WRN HIGH PLAINS MOVES SEWD. TEMPS TRICKY
CALL WITH WITH QUASI STATIONARY FRON AND OUTFLOW BOUNDARIES. AREAS
SOUTH OF BOUNDARIES LIKWLY PUSHING INTO 90S AGAIN TODAY BUT MAINLY
80S TO N.

.OMA...NONE
WIESE

In the hours before

Local storm report, Jul 3, 2:54 AM CDT, 4 hours 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
254 AM CDT TUE JUL 03 2001

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

0134 AM    1 W CLEARWATER            NE   1 INCH HAIL
07/03/01   ANTELOPE                       REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

0146 AM    NELIGH                    NE   1 INCH HAIL
07/03/01   ANTELOPE                       REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

0220 AM    TILDEN                    NE   WIND DAMAGE
07/03/01   MADISON                        POWER LINES AND TREE
                                          LIMBS DOWN BETWEEN
                                          BATTLE CREEK AND
                                          TILDEN. REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

Local storm report, Jul 3, 4:21 AM CDT, 2 hours 35 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
421 AM CDT TUE JUL 03 2001

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

0340 AM    14 WSW OMAHA              NE   1.75 INCH HAIL
07/03/01   DOUGLAS                        REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

Special weather statement, Jul 3, 5:25 AM CDT, 1 hour 31 minutes before

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-031645-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
525 AM CDT TUE JUL 3 2001

STORM SPOTTER ACTIVATION MAY BE REQUIRED TODAY AND TONIGHT IN
EASTERN NEBRASKA AND SOUTHWEST IOWA.

SCATTERED THUNDERSTORMS IN PORTIONS OF EASTERN NEBRASKA AND
SOUTHWEST IOWA ARE FORECAST TO END THIS MORNING. HOWEVER WITH A
UNSTABLE AND MOIST AIR MASS REMAINING OVER THE AREA...ALONG WITH A
NEARLY STATIONARY FRONT EXTENDING ACROSS NORTHERN IOWA INTO
SOUTHWEST NEBRASKA COUPLED WITH THUNDERSTORM OUTFLOW
BOUNDARIES...ADDITIONAL THUNDERSTORMS MAY REDEVELOP AGAIN LATER THIS
AFTERNOON OR TONIGHT AS UPPER AIR DISTURBANCES MOVE ACROSS THE
PLAINS.

BASED ON EXPECTED INSTABILITY AND WIND SHEAR SOME OF THE STORMS COULD
BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS THE MAIN RISK. IN
ADDITION WITH ABUNDANT MOISTURE..".AVAILABLE AREAS OF HEAVY RAIN ARE
POSSIBLE.

GW

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 2, 9:34 PM CDT	Severe Thunderstorm Warning	OAX	Knox	56 min
Jul 2, 9:59 PM CDT	Severe Thunderstorm Warning	OAX	Antelope	61 min
Jul 2, 10:31 PM CDT	Severe Thunderstorm Warning	OAX	Knox, Pierce	44 min
Jul 2, 10:34 PM CDT	Flash Flood Warning	OAX	Knox	5 hr
Jul 2, 11:17 PM CDT	Severe Thunderstorm Warning	OAX	Knox	43 min
Jul 2, 11:35 PM CDT	Severe Thunderstorm Warning	OAX	Wayne	40 min
Jul 3, 1:26 AM CDT	Severe Thunderstorm Warning	OAX	Antelope	49 min
Jul 3, 2:03 AM CDT	Severe Thunderstorm Warning	OAX	Madison	42 min
Jul 3, 2:23 AM CDT	Severe Thunderstorm Warning	OAX	Platte, Stanton	67 min
Jul 3, 2:48 AM CDT	Severe Thunderstorm Warning	OAX	Colfax	57 min
Jul 3, 3:37 AM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy	38 min
Jul 3, 3:49 AM CDT	Severe Thunderstorm Warning	OAX	Madison, Platte	41 min
Jul 3, 4:41 AM CDT	Severe Thunderstorm Warning	OAX	Cass	49 min
Jul 3, 4:54 AM CDT	Severe Thunderstorm Warning	OAX	Otoe	51 min
Jul 3, 1:49 AM CDT	Severe Thunderstorm Warning	OAX	Monona	26 min

Nearby

Severe Thunderstorm Warnings in Iowa, 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.