A nearly stationary thunderstorm dropped an estimated 4 to 5 inches of rain. A flash flood occurred which washed out gravel roads and cut a natural gas line.
Every event with a place to put it. Tap one for its entry below.
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.
The episode as NWS PUB wrote it up.
A nearly stationary thunderstorm dropped an estimated 4 to 5 inches of rain. A flash flood occurred which washed out gravel roads and cut a natural gas line. Gas was unavailable in the Walsenburg area in Huerfano County for nearly a week.
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 Pueblo, CO wrote its last area forecast discussion before the first event at May 21, 2:17 PM MST, 1 hour 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 317 PM MDT THU MAY 21 2009 .SHORT TERM... (TONIGHT AND FRIDAY) A COUPLE STRONG TO SEVERE STORMS DEVELOPED ALONG THE SRN I-25 CORRIDOR THIS AFTERNOON. THE STORMS TODAY ARE VERY SLOW MOVING AND ARE PRODUCING HEAVY RAIN...SO WITH THE STRONGER STORMS THIS AFTERNOON AND THIS EVENING...FLASH FLOODING WILL CONTINUE TO BE A THREAT. SHOULD SEE SOME DIURNAL DECREASE IN THE COVERAGE OF PCPN LATER THIS EVENING...BUT WL STILL KEEP SOME SCT POPS OVR THE MTS AND ISOLD ELSEWHERE. FORECAST SOUNDINGS ALONG THE I-25 CORRIDOR SHOW A SATURATED LAYER IN THE LOWER LEVELS LATE TONIGHT AND EARLY FRI SO SHOULD SEE A LOT OF LOW CLOUDS DEVELOP...ALONG WITH AREAS OF FOG. AN UPR LOW WL REMAIN OVR AZ TONIGHT AND FRIDAY...WITH MSTR CONTINUING TO STREAM UP OVR THE FORECAST AREA FROM THE SOUTH AND PRECIPITABLE WATER VALUES OVR 200 PERCENT OF NORMAL FROM THE I-25 CORRIDOR AND WESTWARD...AND BETWEEN 100 AND AROUND 130 PERCENT OF NORMAL OVER THE SOUTHEAST PLAINS. WITH THE MOIST ATMOSPHERE OVR THE AREA STILL ON FRI WL AGAIN SEE PCPN COVERAGE INCREASE IN THE AFTERNOON HRS. IT LOOKS LIKE THE MOST UNSTABLE AREAS FRIDAY AFTERNOON WL BE ALONG THE I-25 CORRIDOR AND SE MTS WHERE LAPSE RATES WILL BE 7-8 C/KM AND CAPE VALUES WILL BE 400-600 J/KG. WL KEEP SCT POPS AND HIGHER FROM THE I-25 CORRIDOR...BUT IT LOOKS LIKE THE FAR SE PLAINS WL BE A LITTLE MORE STABLE AND BOTH THE NAM AND GFS SHOW LITTLE PCPN SO WL DECREASE POPS SOME. GUIDANCE TEMPS FOR FRI ARE IN GOOD AGREEMENT WITH HIGHS IN THE 70S TO AROUND 80 OVR MOST OF THE SE PLAINS...WL INCREASE MAX TEMPS JUST A LITTLE...AS IT LOOKS LIKE THERE WL PROBABLY BE A LITTLE MORE SUN TOMORROW IN THIS AREA. .LONG TERM... (FRIDAY NIGHT-THURSDAY) FRIDAY NIGHT-SUNDAY...UNSETTLED WEATHER PATTERN TO CONTINUE WITH MINOR EMBEDDED WAVES (BEST SEEN IN H30-H20 LAYER POT VORT) MOVING THROUGH THE WEAK AND MOIST SOUTH TO SOUTHWEST FLOW ALOFT THROUGH THE DAY SUNDAY. MODELS CONTINUE TO INDICATE BEST INSTABILITY ACROSS THE HIGHER TERRAIN AND HAVE KEPT BEST POPS ACROSS THE MTS THROUGH THE PERIOD. SOUNDINGS INDICATING A MORE STABLE ATMOSPHERE ACROSS THE FAR EASTERN PLAINS FRIDAY EVENING WITH BETTER CHANCES OF SEEING DEEP MOIST CONVECTION SATURDAY AND SUNDAY WITH ADDED UVV ASSOCIATED WITH MINOR EMBEDDED WAVES. MODELS ALSO CONTINUE INDICATE ABUNDANT AVAILABLE MOISTURE AND ALONG WITH WEAK FLOW ALOFT...STORMS WILL HAVE THE POTENTIAL TO PRODUCE MODERATE TO LOCALLY HEAVY RAINFALL THROUGH THE WEEKEND. WITH THE WEAK FLOW ALOFT...ORGANIZED SEVERAL WEATHER DOES NOT LOOK PROMISING...THOUGH WITH DECENT LOW LEVEL MOISTURE IN PLACE...CANT RULE OUT AN ISOLATED SEVERE STORM THROUGH THE WEEKEND. SUNDAY NIGHT-THURSDAY...A SLIGHT DECREASE IN AVAILABLE MOISTURE PROGGED AS FLOW ALOFT BECOMES MORE WESTERLY SUNDAY NIGHT AND MONDAY WITH A WEAK UPPER TROUGH AND ASSOCIATED COLD FRONT MOVING ACROSS THE NORTHERN TIER. MODELS INDICATING PRE FRONTAL TROUGH ACROSS THE EASTERN PLAINS ON MONDAY AFTERNOON AND TRY AND SCOUR DRY LINE INTO WESTERN KANSAS. NORTHERN TIER WAVE CONTINUES ACROSS THE NORTHERN HIGH PLAINS MONDAY NIGHT WITH BACKDOOR COLD FRONT MOVING ACROSS EASTERN COLORADO TUESDAY MORNING. WITH ENOUGH RESIDUAL MOISTURE AND LATE MAY SOLAR HEATING...HAVE KEPT ISOLATED TO SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN AND HIGH VALLEYS THROUGH THE PERIOD. HAVE GONE WITH ISOLATED TO SCATTERED POPS ACROSS THE EASTERN PLAINS SUNDAY NIGHT THROUGH TUESDAY WITH UNCERTAINTY ON TIMING OF BOUNDARY ACROSS THE PLAINS. THE PLAINS SHOULD BE TOO STABLE TUESDAY NIGHT AND WEDNESDAY BEHIND FRONT WITH CHANCES OF DEEP MOIST CONVECTION RETURNING ON THURSDAY. -MW && .AVIATION... SCATTERED SHOWERS AND ISOLD TSTMS WILL BE POSSIBLE THIS EVENING AT THE THREE TAF SITES. THE LATER TONIGHT ISOLD SHOWERS WL BE POSSIBLE...WITH IFR CIGS LIKELY AT KCOS AFTER MIDNIGHT...AND PROBABLY MVFR CIGS AT KPUB AND KALS. THE LOW CIGS WL LIKELY CONTINUE THROUGH ABOUT 14Z OR 15Z...WITH VFR CONDITIONS THEREAFTER. HOWEVER...FRI AFTERNOON MVFR CIGS COULD AGAIN OCCUR IN SHOWERS AND TSTMS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && 28/23
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PUEBLO CO 637 AM MDT THU MAY 21 2009 COZ058>089-093>099-221245- WESTERN MOSQUITO RANGE/EAST LAKE COUNTY ABOVE 11000 FT- LEADVILLE VICINITY/LAKE COUNTY BELOW 11000 FT- EASTERN SAWATCH MOUNTAINS ABOVE 11000 FT- WESTERN CHAFFEE COUNTY BETWEEN 9000 AND 11000 FT- CENTRAL CHAFFEE COUNTY BELOW 9000 FT- WESTERN MOSQUITO RANGE/EAST CHAFFEE COUNTY ABOVE 9000 FT- SAGUACHE COUNTY WEST OF CONTINENTAL DIVIDE BELOW 10000 FT- SAGUACHE COUNTY EAST OF CONTINENTAL DIVIDE BELOW 10000 FT- LA GARITA MOUNTAINS ABOVE 10000 FT- UPPER RIO GRANDE VALLEY/EASTERN SAN JUAN MOUNTAINS BELOW 10000 FT- EASTERN SAN JUAN MOUNTAINS ABOVE 10000 FT- DEL NORTE VICINITY/NORTHERN SAN LUIS VALLEY BELOW 8500 FT- ALAMOSA VICINITY/CENTRAL SAN LUIS VALLEY BELOW 8500 FT- SOUTHERN SAN LUIS VALLEY- NORTHERN SANGRE DE CRISTO MOUNTAINS BETWEEN 8500 AND 11000 FT- NORTHERN SANGRE DE CRISTO MOUNTAINS ABOVE 11000 FEET- SOUTHERN SANGRE DE CRISTO MOUNTAINS BETWEEN 7500 AND 11000 FT- SOUTHERN SANGRE DE CRISTO MOUNTAINS ABOVE 11000 FT- NORTHWESTERN FREMONT COUNTY ABOVE 8500 FT- WESTERN/CENTRAL FREMONT COUNTY BELOW 8500 FT- WET MOUNTAIN VALLEY BELOW 8500 FEET- WET MOUNTAINS BETWEEN 6300 AND 10000 FT- WET MOUNTAINS ABOVE 10000 FT- TELLER COUNTY/RAMPART RANGE ABOVE 7500 FT/PIKES PEAK BETWEEN 7500 AND 11000 FT-PIKES PEAK ABOVE 11000 FT- CANON CITY VICINITY/EASTERN FREMONT COUNTY- NORTHERN EL PASO COUNTY/MONUMENT RIDGE/RAMPART RANGE BELOW 7500 FT- COLORADO SPRINGS VICINITY/SOUTHERN EL PASO COUNTY/RAMPART RANGE BELOW 7400 FT-PUEBLO AND VICINITY/PUEBLO COUNTY BELOW 6300 FT- WALSENBURG VICINITY/UPPER HUERFANO RIVER BASIN BELOW 7500 FT- TRINIDAD VICINITY/WESTERN LAS ANIMAS COUNTY BELOW 7500 FT- CROWLEY COUNTY-LA JUNTA VICINITY/OTERO COUNTY- EASTERN LAS ANIMAS COUNTY-WESTERN KIOWA COUNTY- EASTERN KIOWA COUNTY-LAS ANIMAS VICINITY/BENT COUNTY- LAMAR VICINITY/PROWERS COUNTY-SPRINGFIELD VICINITY/BACA COUNTY- 637 AM MDT THU MAY 21 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL...EAST CENTRAL...SOUTH CENTRAL AND SOUTHEAST COLORADO. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS WILL BE FOUND FROM THE I-25 CORRIDOR WESTWARD DURING THE AFTERNOON...WITH GENERALLY LESS ACTIVITY OUT EAST ACROSS THE PLAINS. THE PRIMARY THREATS FROM STORMS TODAY WILL BE HEAVY RAINFALL...WIND GUSTS TO AROUND 40 MPH...LOCAL PEA SIZE HAIL...AND LIGHTNING. TONIGHT...SCATTERED THUNDERSTORMS WILL CONTINUE ACROSS THE MOUNTAINS...HIGH VALLEYS...AND ADJACENT PLAINS DURING THE EVENING HOURS...AND THEN DIE DOWN AROUND MIDNIGHT. THE PRIMARY THREATS WILL REMAIN THE SAME AS DURING THE AFTERNOON. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY A MILD AND RELATIVELY MOIST METEOROLOGICAL PATTERN WILL ALLOW ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY TO CONTINUE ACROSS SOUTHERN COLORADO THROUGH THE PERIOD. THE PRIMARY METEOROLOGICAL THREATS FROM STORMS ON THESE DAYS WILL BE LIGHTNING...GUSTY WINDS...HEAVY RAIN AND POSSIBLY SOME SMALL STREAM FLOODING. IN ADDITION...ONE OR TWO STORMS COULD BE SEVERE ON ANY GIVEN DAY(ESPECIALLY FROM MONDAY INTO NEXT WEDNESDAY)...WHICH WILL BE CAPABLE OF PRODUCING WIND GUSTS AROUND 60 MPH AND HAIL AROUND 1 INCH IN DIAMETER. .SPOTTER INFORMATION STATEMENT... WEATHER CONDITIONS THAT MEET REPORTING CRITERIA FOR SPOTTERS WILL BE POSSIBLE AFTER 12 PM MDT THIS AFTERNOON OVER THE MOUNTAINS...HIGH VALLEYS...AND I-25 CORRIDOR.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PUEBLO CO
337 PM MDT THU MAY 21 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0300 PM HEAVY RAIN 6 NNE LA VETA 37.60N 104.98W
05/21/2009 M2.20 INCH HUERFANO CO TRAINED SPOTTER
HEAVY RAIN STILL OCCURRING
&&The Pueblo radar (KPUX), 130 km away, was scanning. The volume nearest the first event began at 22:55 UTC.
1 flash flood. Local standard time, as filed.
I-25 frontage road and County Road 42 flooded.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2009Every state in 2009This day in weather historyWarnings in Colorado, May 2009
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: 170030.