Flood in Montana, May 21 to 24, 2002

Name: Flood in Montana, May 21 to 24, 2002
Start: 2002-05-21T16:00
End: 2002-05-24T14:00
Location: Montana

May 21 to 24, 2002 · NWS MSO · 1 event in 1 county or zone

3 feet above flood stage. Some houses were flooded in subdivisions along the river, but no major property damage was reported.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS MSO wrote it up.

Fueled by several days of spring rains, the Yaak River peaked at 9.33 feet, 1.3 feet above flood stage. Some houses were flooded in subdivisions along the river, but no major property damage was reported. The Upper Ford Road, a perennial problem spot, washed out from the flood.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Missoula, MT wrote its last area forecast discussion before the first event at May 21, 1:20 PM MST, 2 hours 40 minutes earlier.

Area forecast discussion, May 21, 1:20 PM MST, 2 hours 40 minutes before

WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1246 PM MDT TUE MAY 21 2002

.SHORT TERM...NUMEROUS HIGHLIGHTS OUT FOR TONIGHT THROUGH WEDNESDAY.
CURRENT SATELLITE PIC SHOWS UPPER LOW OVER ID WITH AMPLE WRAP AROUND
MOISTURE. 18Z MESOETA SHOWS PRECIP CONTINUING THROUGH WED AS UPPER
LOW OVER CNTRL MT WILL CONTINUE TO BRING WRAP AROUND PCPN TO
WRN MT. BANKS IN SMALL STREAMS ARE ALREADY CLOSE TO OR OVER
BANKFULL AND THESE WILL FEED INTO THE MAINSTEM RIVERS MAKING THEM
PRONE TO SOME FLOODING. HENCE THE ISSUANCE OF FLOOD WATCHES TONIGHT.

SNOW LEVELS WILL BEGIN TO DROP THIS EVENING AS THE UPPER LOW MOVES A
BIT EAST AND DRAWS IN SOME COOLER AIR FROM THE NORTH. WITH
SIGNIFICANT MOISTURE EXPECTED A HEAVY SNOW WARNING HAS BEEN ISSUED.
SNOW LEVELS WILL DROP SIGNIFICANTLY TO WHERE THE VALLEYS MAY SEE A
MIX OF SNOW WITH RAIN BY SUNRISE WED MORNING...BUT THE ACCUMULATING
SNOW WILL REMAIN ABOVE 5500 FEET...WITH ACCUMULATING SNOW DROPPING
TO 4500 FEET IN WEST GLACIER.  GRADIENTS TIGHTEN TONIGHT WHICH WILL
INCREASE WEST-NORTHWEST WINDS...BUT BELOW ADVISORY CRITERIA.

UPPER LOW MOVES EAST THU AND ZONAL FLOW SETS UP LATE THU AND FRI TO
SET UP FOR A DRY DAY FRI. RPN

.LONG TERM...SOME RIDGING PROGGED AHEAD OF NEXT UPPER LOW MOVING INTO
THE COAST SATURDAY. TROF THAT DEVELOPS DURING THE WEEKEND IS FAIRLY
MOIST FOR BOTH SATURDAY AND SUNDAY AS SOUTHWEST FLOW DEVELOPS OVER
THE AREA. ZONAL FLOW OVER THE AREA FOR MONDAY AND ANOTHER WEAK RIDGE
FOR TUESDAY AHEAD OF ANOTHER UPPER LOW MOVING TOWARD THE COAST. WILL
LEAVE CHANCE OF PRECIPITATION FOR SATURDAY THRU MONDAY WITH AVAILABLE
MOISTURE AND WILL GO DRY FOR DAY 7. TEMPERATURES SHOULD BE COOL FOR
THE SATURDAY-MONDAY TIME FRAME AND WARM UP A TAD ON TUESDAY. KPB

.MSO...FLOOD WARNING FOR THE YAAK RIVER THROUGH THIS EVENING

       FLOOD WATCH FOR THE SAINT REGIS RIVER...FISHER RIVER...THE
       BITTERROOT RIVER FROM VICTOR TO FLORENCE...THE NORTHFORK...
       MIDDLE FORK...AND MAINSTEM OF THE FLATHEAD RIVERS

       FLOOD ADVISORY THROUGH THIS EVENING FOR MTZ001-004-005-006

       HEAVY SNOW WARNING TONIGHT THROUGH WEDNESDAY ABOVE 5500 FEET
       IDZ005-006-009-010
       HEAVY SNOW WARNING TONIGHT THROUGH WEDNESDAY ABOVE 5500 FEET
       MTZ001-004-007
       HEAVY SNOW WARNING FOR MTZ002-043 TONIGHT AND WEDNESDAY

...7-DAY SPOT TEMPS AND POPS...
LIB REB 043/049 039/057 040/067 40+74221
     EEEB 046/067 044/065 044/065 043/068 2923544321
FCA REB 041/047 038/056 038/066 40+74221
     EEEB 044/065 043/063 042/064 041/064 2923544321
POL REB 043/049 036/057 042/066 40+74221
     EEEB 044/067 044/063 046/064 045/064 2925544323
MSO REB 042/047 036/055 038/067 40+75210
     EEEB 045/066 044/064 044/064 043/066 2905533221
HMM REB 043/048 037/056 039/065 40+75210
     EEEB 045/068 044/065 043/065 043/069 2904533222
BTM REB 035/047 031/049 029/062 40+64210
     EEEB 037/063 038/062 039/061 038/063 2903443111
ORO EEB 043/058 041/062 045/070 40743210
     EEEB 051/072 049/067 052/069 051/070 2925543221
GRV EEB 035/049 031/057 040/065 40743210
     EEEB 047/068 045/063 047/065 046/067 2925543221
SMN EEB 039/048 034/056 037/065 40743110
     EEEB 039/067 042/064 044/064 042/067 2903432111

In the hours before

Local storm report, May 21, 10:03 AM MST, 5 hours 57 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
955 PM MDT TUE MAY 21 2002

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

0428 PM    10 N SALMON               ID   NON TSTM WIND 64 MPH
05/19/02   LEMHI                          KRILEY CREEK RAWS STATION

0500 PM    2 S MISSOULA              MT   60 MPH WIND GUST
05/19/02   MISSOULA                       ESTIMATED BY OFF-DUTY
                                          NWS EMPLOYEE IN MILLER
                                          CREEK AREA

0520 PM    MISSOULA                  MT   OFF-DUTY NWS EMPLOYEE
05/19/02   MISSOULA                       REPORTED A WALL CLOUD

0920 PM    PINNACLE                  MT   1 INCH HAIL
05/19/02   FLATHEAD

0700 PM    2 S LIBBY                 MT   60 MPH WIND GUST
05/19/02   LINCOLN                        ESTIMATED BY SPOTTER
                                          SPOTTER AND NEWS REPORTER
                                          REPORTED NUMEROUS TREES
                                          AND POWER LINES DOWN
                                          FROM THOMPSON LAKES TO
                                          LIBBY

Local storm report, May 21, 10:11 AM MST, 5 hours 49 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTION
NATIONAL WEATHER SERVICE MISSOULA MT
955 AM MDT TUE MAY 21 2002

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

0428 PM    10 N SALMON               ID   NON TSTM WIND 64 MPH
05/19/02   LEMHI                          KRILEY CREEK RAWS STATION

0500 PM    2 S MISSOULA              MT   60 MPH WIND GUST
05/19/02   MISSOULA                       ESTIMATED BY OFF-DUTY
                                          NWS EMPLOYEE IN MILLER
                                          CREEK AREA

0520 PM    MISSOULA                  MT   OFF-DUTY NWS EMPLOYEE
05/19/02   MISSOULA                       REPORTED A WALL CLOUD

0920 PM    PINNACLE                  MT   1 INCH HAIL
05/19/02   FLATHEAD

0700 PM    2 S LIBBY                 MT   60 MPH WIND GUST
05/19/02   LINCOLN                        ESTIMATED BY SPOTTER
                                          SPOTTER AND NEWS REPORTER
                                          REPORTED NUMEROUS TREES
                                          AND POWER LINES DOWN
                                          FROM THOMPSON LAKES TO
                                          LIBBY

0715 PM    LIBBY                     MT   WIND DAMAGE
05/19/02   LINCOLN                        NEWS REPORTER REPORTED
                                          ROAD SIGN BLOW DOWN AND
                                          ROOF BLOWN OFF BUILDING
                                          ALMOST HIT A CAR

Local storm report, May 21, 10:23 AM MST, 5 hours 37 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTION
NATIONAL WEATHER SERVICE MISSOULA MT
1030 AM MDT TUE MAY 21 2002

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

1228 PM    10 N SALMON               ID   NON TSTM WIND GUST 73 MPH
05/20/02   LEMHI                          KRILEY CREEK RAWS STATION
                                          REPORTED SUSTAINED WINDS
                                          OF 34 TO 45 MPH AND WIND
                                          GUSTS 59 TO 73 MPH BETWEEN
                                          1228 PM AND 328 PM MDT.

1252 PM    SALMON                    ID   NON TSTM WIND 44 MPH
05/20/02   LEMHI                          SALMON RAWS STATION
                                          REPORTED SUSTAINED WIND
                                          OF 44 MPH WITH GUST TO
                                          50 MPH

0109 PM    22 SE HAMILTON            MT   NON TSTM WIND GUST 52 MPH
05/20/02   RAVALLI                        TEE POINT RAWS STATION
                                          REPORTED WIND GUSTS BETWEEN
                                          50 TO 52 MPH FROM 109 PM TO
                                          309 PM MDT

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flood. Local standard time, as filed.

Flood, Kootenai/Cabinet Region

When: May 21, 4:00 PM MST to May 24, 2:00 PM MST
Where: Kootenai/Cabinet Region forecast zone
Reported by: NEWSPAPER
Coordinates: 48.171, -114.863 (the zone’s center; the record gives no point)

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Montana in 2002 Every state in 2002 This day in weather history Warnings in Montana, May 2002

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5295649.