Alert archive / Minnesota / Flash Flood Warnings in 2007

Flash Flood Warning 2, NWS Duluth, MN

May 21, 2007Saint Louis County, Minnesota

NWS Duluth, MN issued this flash flood warning at May 21, 2007, 10:15 AM CDT for Saint Louis County, Minnesota. It took effect at May 21, 2007, 10:26 AM CDT. It was in force for 109 min. 2 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
May 21, 2007, 10:15 AM CDT (15:15 UTC)
In effect from
May 21, 2007, 10:26 AM CDT
Expired
May 21, 2007, 12:15 PM CDT
In force
109 min
Issued by
NWS Duluth, MN
Area
Whole counties

County Saint Louis County, MN

The radar

The Duluth radar (KDLH), 86 km from the middle of the area, began a volume at 15:15 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
May 21, 10:30 AM CDTHEAVY RAIN 1.4Tower, MN1.4 INCHES IN 1 HOUR
May 21, 10:30 AM CDTHEAVY RAIN 1.51 S Soudan, MN1.5 INCHES IN 1.5 HOURS

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

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 3.3 hours before the alert went out and 126 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, International Fa, MN at 12:00Z on 2007-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, International Fa, MN at 12:00Z on 2007-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
690 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
173 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KDLH 211526 CCA
FFWDLH
MNC137-211715-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING...CORRECTED
NATIONAL WEATHER SERVICE DULUTH MN
1015 AM CDT MON MAY 21 2007

THE NATIONAL WEATHER SERVICE IN DULUTH MN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL AND NORTHERN ST. LOUIS COUNTY IN NORTHEAST MINNESOTA...

* UNTIL 1215 PM CDT

* AT 1015 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
  VERY HEAVY RAIN FROM THUNDERSTORMS CAPABLE OF PRODUCING FLASH      
  FLOODING NEAR AND AROUND VERMILION LAKE.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

LAT...LON 4784 9271 4782 9227 4797 9225 4801 9265

$$

BERDES

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 Duluth, MN wrote its last area forecast discussion before this flash flood warning went out at May 21, 3:46 AM CDT, 6 hours 29 minutes earlier.

Area forecast discussion, May 21, 3:46 AM CDT, 6 hours 29 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
346 AM CDT MON MAY 21 2007

.DISCUSSION...ANOMALOUS SFC HIGH PRESSURE OVER ONTARIO MAINTAINING
WEDGE OF CHILLY AIR ACROSS MOST OF CWA THIS MORNING. A SFC WARM
FRONT IS PUSHING TOWARDS THE REGION FROM SOUTHERN MN. A RAPID
RETURN FLOW IS OCCURRING ABOVE BDRY LAYER WITH MDT/STRONG
FRONTOGENESIS WITHIN THE SFC/85H LAYER. LLJ HAS ASSISTED IN
DEVELOPMENT OF ELEVATED CONVECTION THIS MORNING AS ANIMATION OF
RADAR IMAGERY...COINCIDENT WITH NAM12 85H ISOTACHS...PLACES
CURRENT CLUSTER OF DEVELOPMENT WITHIN LEFT EXIT REGION OF 85H JET.
ACTIVITY IS DEVELOPING EASTWARD ALONG MARINE BOUNDARY ACROSS SOUTH
SHORE. SOME DEEPENING OF 85/70H MSTR LYR INDICATED ON SPC
MESOANALYSIS ACROSS SRN CWA. A VERY WEAK SHORTWAVE IS CURRENTLY
PUSHING ACROSS THE APEX OF THE MID LVL RIDGE OVERHEAD...AT LEAST
ACCORDING TO MDL GUIDANCE.

EXPECT AREA OF LOW/MID LVL FRONTOGENESIS TO PUSH NE THIS MORNING
AND ACTIVITY SHOULD WANE AS OVERALL FORCING/MSTR DEPTH DECEASES.
WILL USE BROAD BRUSH AREA OF LOW POPS FOR FCST TODAY AS SW FLOW
ALOFT CONTINUES...WITH HARD TO LOCATE SHORTWAVES WIGGLING ACROSS
REGION. SOME BREAKS IN CLOUD DECK...ESPECIALLY WRN CWA THIS AFTERNOON.

TUESDAY/WEDNESDAY...SIGNIFICANT INFLUX OF MOISTURE EXPECTED AS SFC/85H FLOW
INTENSIFIES. SLOW MOVING FRONTAL SYSTEM WILL ALLOW 85/70H MSTR
FLUX ANOMALIES TO EXCEED 3 S.D. ABOVE AVERAGE SO LCLY HEAVY RAIN POSSIBLE.
UNIDIRECTIONAL FLOW SFC/85 TUESDAY AFTERNOON OVER MOST OF CWA SO
SHOULD SEE VERY BREEZY CONDITIONS...WITH G35KT AT TIMES. ALTHOUGH
SPC HAS REMOVED AREA FROM SLGHT RISK...STILL NEED TO WATCH FOR
CONVECTIVE DEVELOPMENT AS KINEMATICS SUGGEST SHEAR PROFILE WILL PROVIDE
FAVORABLE BACKGROUND ON WEDNESDAY ALTHOUGH SFC BASED STABILITY PARAMETERS
MAY BE LIMITED.

&&

.AVIATION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WERE
OCCURRING NORTH OF A WARM FRONT THAT STRETCHED ACROSS SOUTHERN
MINNESOTA SOUTHEAST INTO ILLINOIS EARLY THIS MORNING. AREAS OF
MVFR CEILINGS WERE ALSO PRESENT ACROSS FAR NORTHERN MINNESOTA. THE
WARM FRONT WILL LIFT NORTH AND LIE ROUGHLY FROM SOUTHERN WISCONSIN
INTO NORTHWEST MINNESOTA BY EVENING. THERE WILL CONTINUE TO BE A
CHANCE FOR THUNDERSTORMS TODAY ACROSS MUCH OF THE REGION. MVFR
CEILINGS AND VISIBILITIES CAN BE EXPECTED WITH THE
STORMS...OTHERWISE CEILINGS WILL BECOME VFR THIS AFTERNOON.

A SUBSTANTIAL INVERSION WILL BE PRESENT EARLY THIS MORNING...AND
AREAS OF NON-CONVECTIVE LOW LEVEL WIND SHEAR WILL BE POSSIBLE.

&&

POINT TEMPS/POPS...
DLH  64  50  75  50 /  30  10  30  50
INL  72  55  80  55 /  20  30  60  60
BRD  80  59  79  55 /  20  10  50  60
HYR  75  55  80  57 /  20  10  20  40
ASX  70  54  81  57 /  30  10  10  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...

MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ140-
     LSZ141-LSZ142-LSZ143-LSZ144-LSZ145-LSZ146-LSZ147.

CANNON/MELDE
Hazardous weather outlook, May 21, 4:27 AM CDT, 5 hours 48 minutes before
HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE DULUTH MN
427 AM CDT MON MAY 21 2007

LSZ121-140>148-162-MNZ010>012-018>021-025-026-033>038-WIZ001>004-
006>009-220930-
BAYFIELD TO OAK POINT WI-GRAND PORTAGE TO GRAND MARAIS MN-
GRAND MARAIS TO TACONITE HARBOR MN-
TACONITE HARBOR TO SILVER BAY HARBOR MN-
SILVER BAY HARBOR TO TWO HARBORS MN-TWO HARBORS TO DULUTH MN-
DULUTH MN TO PORT WING WI-PORT WING TO SAND ISLAND WI-
SAND ISLAND TO BAYFIELD WI-OAK POINT TO SAXON HARBOR WI-
OPEN WATERS OF LAKE SUPERIOR WEST OF A LINE FROM SAXON HARBOR WI
TO GRAND PORTAGE MN-KOOCHICHING-NORTHERN ST. LOUIS-
NORTHERN COOK/NORTHERN LAKE-NORTHERN ITASCA-CENTRAL ST. LOUIS-
SOUTHERN LAKE/LAKESHORE-SOUTHERN COOK/LAKESHORE-NORTHERN CASS-
SOUTHERN ITASCA-SOUTHERN CASS-CROW WING-NORTHERN AITKIN-
SOUTHERN AITKIN-CARLTON/SOUTHERN ST. LOUIS-PINE-DOUGLAS-BAYFIELD-
ASHLAND-IRON-BURNETT-WASHBURN-SAWYER-PRICE-
427 AM CDT MON MAY 21 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MINNESOTA...
NORTHWEST WISCONSIN AND WESTERN LAKE SUPERIOR.

.DAY ONE...TODAY AND TONIGHT

A SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM GRAND PORTAGE SOUTH
TO THE TWIN PORTS...AND EAST TO SAXON HARBOR. NORTHEAST WINDS OF
10 TO 20 MPH WITH 3 TO 5 FOOT WAVES WILL MAKE BOATING HAZARDOUS.
PLEASE REFER TO THE LATEST MARINE FORECAST FOR ADDITIONAL DETAILS.

SCATTERED THUNDERSTORMS MAY PRODUCE GUSTY WINDS AND SMALL HAIL AT
TIMES...ESPECIALLY EARLY THIS MORNING...NEAR THE TWIN PORTS AND
EAST INTO NORTHERN WISCONSIN. ISOLATED THUNDERSTORMS ARE POSSIBLE
AGAIN THIS AFTERNOON ACROSS THE ENTIRE REGION.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A SLOW MOVING FRONTAL SYSTEM WILL APPROACH THE REGION LATE TUESDAY.
VERY GUSTY WINDS...SOME IN EXCESS OF 35 MPH...MAY OCCUR TUESDAY
AFTERNOON FROM ITASCA COUNTY SOUTH TO THE BRAINERD LAKES REGION.
ABUNDANT MOISTURE IS EXPECTED AHEAD OF THE FRONT BY TUESDAY NIGHT.
THE CHANCE FOR LOCALLY HEAVY RAIN WILL INCREASE EARLY WEDNESDAY
OVER WESTERN SECTIONS AND SPREAD EASTWARD DURING THE DAY. IT IS
POSSIBLE THAT DUE TO STRENGTHENING WINDS ASSOCIATED WITH THE
SYSTEM...A FEW STRONG THUNDERSTORMS MAY DEVELOP WEDNESDAY
AFTERNOON. MUCH COOLER AIR WILL RETURN ON THURSDAY AND FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

CANNON

The office that day

Everything else NWS Duluth, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 10:15 AM CDTFlash Flood WarningDLHSaint Louis2 hr
May 21, 3:10 PM CDTSevere Thunderstorm WarningDLHCass35 min
May 21, 5:12 PM CDTSevere Thunderstorm WarningDLHAitkin, Crow Wing33 min
May 21, 5:44 PM CDTSevere Thunderstorm WarningDLHAitkin31 min
May 21, 6:03 PM CDTSevere Thunderstorm WarningDLHCarlton27 min
May 21, 6:31 PM CDTSevere Thunderstorm WarningDLHCarlton44 min
May 21, 6:54 PM CDTSevere Thunderstorm WarningDLHAitkin, Itasca, Saint Louis51 min

Nearby

Flash Flood Warnings in Minnesota, 2007Every flash flood warning in 2007

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.