NOUS44 KHGX 152123 PNSHOU PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 420 PM CDT FRI JUN 15 2001 ...JUNE 2001 NOW THE WETTEST MONTH ON RECORD IN HOUSTON... HOUSTON INTERCONTINENTAL AIRPORT RECEIVED 1.31 INCHES OF RAIN FROM THIS MORNING'S THUNDERSTORMS. THIS BRINGS THE MONTHLY PRECIPITATION TOTAL TO 17.82 INCHES...MAKING JUNE 2001 THE WETTEST MONTH ON RECORD IN HOUSTON. THE PREVIOUS RECORD WAS A HURRICANE-ENHANCED 17.64 INCHES...SET IN OCTOBER OF 1949. A LOOK AT RAINFALL TOTALS DURING TROPICAL STORM ALLISON... PORT OF HOUSTON 36.99 PEARLAND (CLOVER FIELD) 21.41 HOUSTON HOBBY 20.84 DEER PARK 20.53 WESTBURY 19.53 LEAGUE CITY (NWS) 19.41 CONROE 17.48 HOUSTON INTERCONTINENTAL 16.48 TOMBALL (HOOKS AIRPORT) 15.02 HUNTSVILLE (COOP OBSERVER) 13.03 ANAHUAC 13.01 SUGARLAND (HULL AIRPORT) 12.17 JAMAICA BEACH 11.99 ALVIN 11.23 BAYTOWN 9.83 GALVESTON 9.77 ANGLETON/LAKE JACKSON 3.66 BRYAN/COLLEGE STATION 3.49 PALACIOS 3.35 FROM THE HARRIS COUNTY OFFICE OF EMERGENCY MANAGEMENT... GREENS BAYOU AT WEST MT. HOUSTON 35.67 WESTHEIMER AND KIRBY 33.00 HUNTING BAYOU AT I-10 32.91 COWART CREEK AT BAKER (FRIENDSWOOD) 25.98 VINCE BAYOU AT WEST ELLAINE 25.31 GARNERS BAYOU AT BELTWAY 8 SOUTH 24.61 GREENS BAYOU AT US HIGHWAY 59 23.58 BUFFALO BAYOU AT TURNING BASIN 23.54 CLEAR CREEK AT TELEPHONE ROAD 20.04 BRAYS BAYOU AT STELLA LINK 19.72 WHITE OAK BAYOU AT ELLA 18.19 WHILE THE RAINS ASSOCIATED WITH TROPICAL STORM ALLISON WERE TREMENDOUS...SOUTHEAST TEXAS IS NO STRANGER TO HEAVY RAIN EVENTS. IN THE PAST 25 YEARS...THERE HAVE BEEN SEVERAL TROPICAL SYSTEMS AND OTHER FLOODING EVENTS. THE FOLLOWING IS A LOOK AT HOW ALLISON OF 2001 COMPARES TO THESE PREVIOUS EVENTS. (THE FOLLOWING DATA IS STORM-TOTAL PRECIPITATION FROM HISTORIC HEAVY RAIN EVENTS. MOST OF THE TOTALS ARE FROM 3- TO 5-DAY PERIODS. ALTHOUGH SOME ARE OF SHORTER OR SOMEWHAT LONGER DURATION...THE TOTALS INCLUDED HERE ATTEMPT TO ENCOMPASS AS ACCURATELY AS POSSIBLE THE EVENT OF INTEREST.) ==================================================================== THE MOST RECENT HEAVY RAIN EVENTS WERE IN 1998. ENDING A SEVERE DROUGHT...TROPICAL STORM FRANCES IN SEPTEMBER PRODUCED THE MOST IMPRESSIVE RAINFALL TOTALS OF A WET AUTUMN. ANGLETON 19.47 LEAGUE CITY 11.49 BAY CITY 17.14 CLODINE 10.79 HOUSTON-HEIGHTS 15.25 BAYTOWN 10.40 NORTH HOUSTON 14.70 INTERCONTINENTAL 9.33 SPRING BRANCH 14.25 DEER PARK 9.02 CYPRESS 12.84 TOMBALL 8.22 KATY 12.80 HUNTSVILLE 6.87 SUGAR LAND 12.58 CONROE 4.89 OTHER HEAVY RAIN EVENTS FOLLOWED...ONE IN OCTOBER OF 1998... CYPRESS 11.04 INTERCONTINENTAL 5.87 TOMBALL 10.13 CROCKETT 5.75 CONROE 9.30 HUNTSVILLE 5.14 ALVIN 7.12 LEAGUE CITY 2.87 AND ANOTHER IN NOVEMBER OF 1998... TOMBALL 10.89 INTERCONTINENTAL 8.10 CONROE 10.80 SUGAR LAND 7.75 HOUSTON-HEIGHTS 9.24 NORTH HOUSTON 7.34 HUNTSVILLE 8.82 LEAGUE CITY 4.28 HOUSTON-BARKER 8.38 ==================================================================== PERHAPS THE MOST WIDESPREAD EVENT OCCURRED IN OCTOBER OF 1994... WITH ABUNDANT TROPICAL MOISTURE...BUT WITHOUT THE AID OF A TROPICAL CYCLONE. LIBERTY 26.37 TOMBALL 14.82 BAYTOWN 25.66 HUNTSVILLE 14.10 CONROE 23.89 NORTH HOUSTON 12.28 SAN JACINTO DAM 21.77 SUGAR LAND 11.86 PORT OF HOUSTON 21.23 HOUSTON-HEIGHTS 10.33 DEER PARK 18.48 ANAHUAC 10.31 HOBBY AIRPORT 18.03 INTERCONTINENTAL 9.50 WESTBURY 15.58 LEAGUE CITY 4.36 ==================================================================== ONE OF THE MOST RECENT HURRICANES TO MENACE THE UPPER TEXAS COAST...HURRICANE CHANTAL...BROUGHT SOME MEMORABLE RAINS TO SOME LOCATIONS IN LATE JULY AND EARLY AUGUST OF 1989. THOMPSONS 9.56 ALVIN 8.29 HOBBY AIRPORT 8.66 GALVESTON 6.56 SUGAR LAND 8.60 TOMBALL 2.82 WESTBURY 8.30 INTERCONTINENTAL 2.14 MORE MEMORABLE HOWEVER WAS THE FIRST...BUT SOMEWHAT LESS DEVASTATING...TROPICAL STORM ALLISON. ALLISON OF 1989 ALSO STALLED IN SOUTHEAST TEXAS...BRINGING REPEATED HEAVY RAINS TO THE REGION DURING LATE JUNE AND EARLY JULY. ODDLY...BOTH ALLISON OF 1989 AND ALLISON OF 2001 MADE LANDFALL NEAR THE WEST END OF GALVESTON ISLAND...HEADED INTO EAST TEXAS...MOVED BACK TO THE SOUTHWEST... BRINGING TORRENTIAL RAINS TO THE HOUSTON AREA...BEFORE FINALLY DRIFTING OFF TO THE EAST. ANAHUAC 20.50 HOBBY AIRPORT 12.69 BAYTOWN 18.20 ALVIN 11.16 DEER PARK 16.17 DOWNTOWN HOUSTON 10.78 ANGLETON 14.34 TOMBALL 10.06 MATAGORDA 14.29 GALVESTON 9.61 INTERCONTINENTAL 13.98 SUGAR LAND 5.24 SAN JACINTO DAM 13.57 A SECOND HURRICANE...JERRY...AFFECTED THE UPPER TEXAS COAST IN OCTOBER OF 1989. HOWEVER...AS CAN BE THE CASE WITH HURRICANES...THE RAINFALL TOTALS WERE CONSIDERABLY LESS THAN THAT FOUND WITH THE SLOWER-MOVING TROPICAL STORMS. NO HURRICANE HAS MADE LANDFALL ON THE UPPER TEXAS COAST SINCE JERRY IN 1989. ==================================================================== ANOTHER EXAMPLE OF A HURRICANE WITHOUT TORRENTIAL RAIN WAS ALICIA IN AUGUST OF 1983. GALVESTON 7.76 INTERCONTINENTAL 6.71 SUGAR LAND 6.48 ==================================================================== IN THE TRADITION OF TROPICAL STORMS...CLAUDETTE IN JULY OF 1979 BROUGHT INCREDIBLE RAINFALL TOTALS TO SOUTHEAST TEXAS. AN OBSERVER NEAR ALVIN RECORDED 43 INCHES OF RAIN IN A 24-HOUR PERIOD...A U.S. RECORD THAT STANDS TO THIS DAY. AREAS SOUTHEAST OF HOUSTON WERE HIT PARTICULARLY HARD...WITH OTHER LOCATIONS RECEIVING SCANT TOTALS. THE FOLLOWING ARE THE STORM TOTALS... ALVIN (COOP) 45.00 MATAGORDA 14.65 ALVIN (NWS) 30.70 GALVESTON 14.47 LEAGUE CITY 24.90 HOBBY AIRPORT 11.02 FREEPORT 23.59 SAN JACINTO DAM 9.69 PEARLAND 22.60 SUGAR LAND 3.83 ANGLETON 18.61 INTERCONTINENTAL 3.13 ==================================================================== THE ABOVE ARE THE MOST SIGNIFICANT HEAVY RAIN EVENTS OF THE LAST QUARTER CENTURY. MANY PREVIOUS HURRICANES AND TROPICAL STORMS HAVE ALSO BROUGHT TORRENTIAL RAINFALL TO THE REGION...AS WELL SOME SIGNIFICANT NON-TROPICAL SYSTEMS. ONE SUCH OCCASION WAS THE HOUSTON FLOOD OF DECEMBER 1935...DURING WHICH BUFFALO BAYOU ROSE 46 FEET ABOVE ITS NORMAL LEVEL...AND WATER REACHED THE THIRD STORY OF SOME DOWNTOWN BUILDINGS. AS DEVASTATING AS TROPICAL STORM ALLISON WAS THIS PAST WEEK... SOUTHEAST TEXAS HAD ALREADY SEEN ITS SHARE OF HEAVY RAIN EVENTS. WHILE ALLISON OF 2001 RANKS AMONG THE MOST DEVASTATING...THIS LOOK AT SOME RECENT FLOODS SHOWS THAT SUCH EVENTS ARE NOT UNPRECEDENTED. WSFO HGX 39