Alert archive / Iowa / Flash Flood Warnings in 1999
Flash Flood Warning 16, NWS La Crosse, WI
NWS La Crosse, WI issued this flash flood warning at Jul 20, 1999, 11:59 PM CDT for 4 counties in Iowa. It was in force for 6 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
- Jul 20, 1999, 11:59 PM CDT (04:59 UTC)
- Expired
- Jul 21, 1999, 6:00 AM CDT
- In force
- 6 hr
- Issued by
- NWS La Crosse, WI
- Area
- Whole counties
Counties Chickasaw County, IA, Floyd County, IA, Howard County, IA, Mitchell County, IA
The radar
The La Crosse radar (KARX), 129 km from the middle of the area, began a volume at 05:02 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
Minneapolis, MN (KMPX), launched 00:00Z, 5.0 hours before the alert went out and 201 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 678 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 123 m²/s²
- 0-3 km storm-relative helicity
- 248 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KLSE 210500 FFWLSE IAC037-067-089-131-211100- BULLETIN - EAS ACTIVATION REQUESTED FLOOD WARNING NATIONAL WEATHER SERVICE LA CROSSE WI 1159 PM CDT TUE JUL 20 1999 THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A * FLOOD WARNING FOR... MITCHELL COUNTY IN NORTHEASTERN IOWA HOWARD COUNTY IN NORTHEASTERN IOWA FLOYD COUNTY IN NORTHEASTERN IOWA CHICKASAW COUNTY IN NORTHEASTERN IOWA * UNTIL 600 AM CDT * AT 1155 PM CDT...AREA LAW ENFORCEMENT CONTINUED TO REPORT THAT MANY ROADS IN THE WARNED AREA REMAIN CLOSED AND/OR UNDER WATER. NATIONAL WEATHER SERVICE RADAR CONTINUED TO SHOW ADDITIONAL THUNDERSTORMS DEVELOPING ACROSS NORTH-CENTRAL IOWA. THE ACTIVITY WAS MOVING TO THE EAST AT 20 MPH. * SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST ACROSS THE AREA THROUGH THE EARLY MORNING HOURS. THIS WILL PROHIBIT ANY SIGNIFICANT IMPROVEMENT IN FLOODING CONDITIONS. THEREFORE...THE FLOODING IS EXPECTED TO CONTINUE THROUGH EARLY MORNING. TRAVEL IS NOT RECOMMENDED IN THESE COUNTIES. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKJLY. MOVE TO HIGHER GROUND. KRC
What forecasters said that day
The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS La Crosse, WI wrote its last area forecast discussion before this flash flood warning went out at Jul 20, 3:30 PM CDT, 8 hours 29 minutes earlier.
Area forecast discussion, Jul 20, 3:30 PM CDT, 8 hours 29 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 330 PM CDT TUE JUL 20 1999 MAIN CONCERNS ARE CONVECTION OVERNIGHT...AND POSITION OF WARM FRONT TOMORROW. LATEST SURFACE ANALYSIS HAS THE WARM FRONT FROM JUST NORTH OF DVN TO JUST SOUTH OF ALO TO WEST OF MCW. LAPS CAPE VALUES ACROSS SOUTHERN HALF OF FORECAST AREA 2000 TO 2500 WITH VALUES TO 6900 JUST SOUTH OF THE FRONT. HODOGRAPHS FROM THE AREA SHOW ONLY A LITTLE DIRECTIONAL SHEAR...BUT FAIRLY GOOD LENGTH. FLASH FLOOD GUIDANCE VERY LOW WITH INCH OR LESS 6 HOUR VALUES IN SEVERAL COUNTIES. GUIDANCE IS A BIT HIGHER IN TAYLOR AND CLARK COUNTIES IN WISCONSIN. WATER VAPOR IMAGERY SHOWS A COUPLE OF SHORT WAVES COMING AROUND THE RIDGE...THE FIRST A SUBTLE FEATURE IN SOUTHERN MINNESOTA MOVING EAST...AND THE SECOND SHORT WAVE WAS LOCATED IN SOUTHERN NEBRASKA AND WAS MOVING TOWARDS THE NORTH NORTHEAST. EXAMINING THE 12Z ETA/NGM RUNS...PREFER THE ETA SOLUTION. NGM APPEARS TO TAKE PRECIPITATION AND FORCING TO THE EAST TOO QUICKLY. ETA CAPE FIELDS APPEAR TOO LOW...BUT MODIFYING FORECAST SOUNDINGS TO EXPECTED SURFACE CONDITIONS PRODUCE MORE REASONABLE VALUES. PRECIPITABLE WATER VALUES HIGH OVERNIGHT BETWEEN 1.75 AND 2.00 INCHES. BOTH ETA AND NGM FORECAST THE WARM FRONT TO SLOWLY MOVE TO THE NORTH PERHAPS REACHING THE MINNESOTA/IOWA BORDER LATE TONIGHT. SOUTHWEST FLOW CONTINUES TO PUSH THE WARM FRONT TO THE NORTH TO THE NORTHEAST OF THE FORECAST AREA BY 22/00Z. FORECAST SOUNDINGS INDICATE THE CAP WILL INCREASE WEDNESDAY AS WARM AIR ADVECTION CONTINUES. ETA/NGM BOTH FORECAST RELATIVE HUMIDITY VALUES TO DROP OFF TO 50 PERCENT OR LESS BELOW 250 MB BY 22/00Z. GIVEN FLASH FLOOD GUIDANCE AND POTENTIAL FOR HEAVY RAINFALL WILL KEEP THE FLASH FLOOD WATCH GOING THROUGH TONIGHT. CONVECTION MAY BE SEVERE THIS EVENING ESPECIALLY ACROSS SOUTHERN COUNTIES AS INSTABILITY RAPIDLY INCREASES. STILL A QUESTION OF WHERE THE WARM FRONT WILL BE WEDNESDAY AFTERNOON. POSSIBILITY OF OVERNIGHT CONVECTION SUPPRESSING THE FRONT FURTHER SOUTH THAN MODELS FORECAST...THEREFORE WILL LEAVE A LOW POP IN FORECAST. IN THE EXTENDED RIDGE SHOULD BUILD ACROSS THE UPPER MISSISSIPPI RIVER VALLEY AND SHOULD BRING HOT AND HUMID CONDITIONS. COORDINATED WITH DVN/MPX/MKX/GRB. .LSE...FLASH FLOOD WATCH...TONIGHT...MNZ079-086>088-094>096-IAZ008>011-018- 019-029-030-WIZ032>034-041>044-053>055-061. NELSON
In the hours before
Special weather statement, Jul 20, 6:23 PM CDT, 5 hours 36 minutes before
IAZ029-202350- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 623 PM CDT TUE JUL 20 1999 ...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM FOR FAYETTE COUNTY... AT 620 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUE TO INDICATE A SEVERE THUNDERSTORM OVER THE SOUTHWESTERN PART OF THE COUNTY. THE HEAVIEST PORTION OF THE STORM WAS LOCATED FROM WESTGATE...28 MILES NORTHEAST OF WATERLOO...TO OLWEIN AND CONTINUED TO MOVE TO THE EAST AT 25 MPH. THE STORM WILL THREATEN THE COMMUNITIES OF MAYNARD AND STANLEY DURING THE NEXT 20 MINUTES. TUNE IN NOAA WEATHER RADIO...YOUR LOCAL RADIO OR TV STATION...OR LOCAL CABLE TELEVISION FOR THE LATEST WEATHER INFORMATION. BREESER
Special weather statement, Jul 20, 6:23 PM CDT, 5 hours 36 minutes before
IAZ029-202350- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 623 PM CDT TUE JUL 20 1999 ...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM FOR FAYETTE COUNTY... AT 620 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUE TO INDICATE A SEVERE THUNDERSTORM OVER THE SOUTHWESTERN PART OF THE COUNTY. THE HEAVIEST PORTION OF THE STORM WAS LOCATED FROM WESTGATE...28 MILES NORTHEAST OF WATERLOO...TO OLWEIN AND CONTINUED TO MOVE TO THE EAST AT 25 MPH. THE STORM WILL THREATEN THE COMMUNITIES OF MAYNARD AND STANLEY DURING THE NEXT 20 MINUTES. TUNE IN NOAA WEATHER RADIO...YOUR LOCAL RADIO OR TV STATION...OR LOCAL CABLE TELEVISION FOR THE LATEST WEATHER INFORMATION. BREESER
Special weather statement, Jul 20, 10:03 PM CDT, 1 hour 56 minutes before
IAZ008>11-018-019-029-030-WIZ054-055-061-210330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1003 PM CDT TUE JUL 20 1999 ...SEVERE THUNDERSTORM WATCH NUMBER 564 EXPIRES FOR ALL OF NORTHEAST IOWA AND PORTIONS OF SOUTHWESTERN WISCONSIN... SEVERE THUNDERSTORM WATCH NUMBER 564 HAS EXPIRED FOR MITCHELL... FLOYD...HOWARD...CHICKASAW...FAYETTE...WINNESHIEK...CLAYTON AND ALLAMAKEE COUNTIES IN NORTHEAST IOWA...AND FOR CRAWFORD...RICHLAND AND GRANT COUNTIES IN SOUTHWEST WISCONSIN. THE THREAT FOR SEVERE WEATHER HAS PASSED. DEVOIR
Special weather statement, Jul 20, 10:03 PM CDT, 1 hour 56 minutes before
IAZ008>11-018-019-029-030-WIZ054-055-061-210330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1003 PM CDT TUE JUL 20 1999 ...SEVERE THUNDERSTORM WATCH NUMBER 564 EXPIRES FOR ALL OF NORTHEAST IOWA AND PORTIONS OF SOUTHWESTERN WISCONSIN... SEVERE THUNDERSTORM WATCH NUMBER 564 HAS EXPIRED FOR MITCHELL... FLOYD...HOWARD...CHICKASAW...FAYETTE...WINNESHIEK...CLAYTON AND ALLAMAKEE COUNTIES IN NORTHEAST IOWA...AND FOR CRAWFORD...RICHLAND AND GRANT COUNTIES IN SOUTHWEST WISCONSIN. THE THREAT FOR SEVERE WEATHER HAS PASSED. DEVOIR
Local storm report, Jul 20, 11:40 PM CDT, 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
1140 PM CDT TUE JUL 20 1999
TIME(CDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0450 PM SOUTHERN PART OF COUNTY IA 1.75 INCH HAIL
07/20/99 FLOYD
0501 PM FLOYD IA 1.75 INCH HAIL
07/20/99 FLOYD
0530 PM NASHUA IA TORNADO
07/20/99 CHICKASAW 2 FARMS DAMAGED
0702 PM COUNTYWIDE IA FLOODING
07/20/99 CHICKASAW NUMEROUS ROADS WERE UNDER
WATER
0723 PM OSAGE IA FLOODING
07/20/99 MITCHELL COUNTY ROAD T38 NEAR OSAGE
UNDERWATER
0800 PM CATARACT WI FLOODING
07/20/99 MONROE WATER OVER ROADS BETWEEN
CATARACT AND FOUR CORNERS
CK/KRC/GD/SJT/STThe office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 7:52 PM CDT | Severe Thunderstorm Warning | ARX | Fayette | 63 min |
| Jul 20, 8:00 PM CDT | Flash Flood Warning | ARX | Chickasaw, Floyd, Howard, Mitchell | 4 hr |
| Jul 20, 8:00 PM CDT | Flash Flood Warning | ARX | Fayette | 4 hr |
| Jul 20, 8:20 PM CDT | Flash Flood Warning | ARX | Clayton | 4 hr |
| Jul 21, 5:45 AM CDT | Flash Flood Warning | ARX | Chickasaw, Floyd, Howard, Mitchell | 6 hr |
| Jul 21, 12:05 PM CDT | Flash Flood Warning | ARX | Chickasaw, Floyd | 9 hr |
Nearby
Flash Flood Warnings in Iowa, 1999Every flash flood warning in 1999
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.