000 FGUS73 KDMX 101346 ESFDSM HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 850 AM CDT FRI OCT 10 2003 ...DROUGHT CONDITIONS UNCHANGED IN CENTRAL IOWA... THE PAST TWO WEEKS HAVE SEEN ALMOST NO RAINFALL ACROSS CENTRAL IOWA WITH LITTLE CHANGE IN THE ONGOING DROUGHT SITUATION. THE END OF THE GROWING SEASON MEANS FAR LESS WATER DEMAND FROM CROPS AND VEGETATION SO THAT DROUGHT INDICES ARE DECLINING MORE SLOWLY THAN EARLIER IN THE SEASON. ONE IMPACT OF THE DROUGHT HAS BEEN REDUCED HARVEST NUMBERS FOR SOYBEANS WITH PRELIMINARY YIELD ESTIMATES DOWN 25 TO 30 PERCENT FROM 2002 ACCORDING TO IOWA STATE UNIVERSITY OFFICIALS. THE DES MOINES HYDROLOGIC SERVICE AREA (HSA) COVERS 51 COUNTIES IN CENTRAL IOWA AND INCLUDES ALL OR PART OF THE FOLLOWING RIVER BASINS: DES MOINES...RACCOON...SOUTH SKUNK...IOWA...CEDAR...EAST NISHNABOTNA...102...AND CHARITON RIVERS. CLIMATOLOGICAL SUMMARY: SEPTEMBER RAINFALL WAS HIGHLY VARIED ACROSS THE DES MOINES HSA WITH ABOVE NORMAL RAINFALL IN SEVERAL SOUTHEAST COUNTIES BUT WELL BELOW NORMAL AMOUNTS IN MUCH OF CENTRAL AND SOUTHWEST IOWA. AMOUNTS IN THE HSA RANGED FROM A LOW OF 1.09 INCHES AT NORTHWOOD TO A HIGH OF 5.30 INCHES AT BLOOMFIELD. AT THE NWS OFFICE IN JOHNSTON SEPTEMBER RAINFALL WAS 2.15 INCHES...ONLY ABOUT TWO-THIRDS OF NORMAL. AFTER NEAR NORMAL SPRING AND EARLY SUMMER RAINFALL...THE SUMMER OF 2003 TURNED QUITE DRY AFTER ABOUT JULY 10. AUGUST WAS THE DRIEST ON RECORD STATEWIDE WITH AN AVERAGE OF 0.96 INCHES...BREAKING THE PREVIOUS AUGUS RECORD OF 1.04 INCHES SET IN 1984. OVERALL SUMMER RAINFALL (JUNE THROUGH AUGUST) WAS ONLY NEAR 50 PERCENT OF ACROSS MUCH OF SOUTHERN AND NORTHEAST IOWA AND NEAR 65 PERCENT OF NORMAL IN CENTRA IOWA. U.S. DROUGHT MONITOR: THE U.S. DROUGHT MONITOR IS A WEEKLY COLLABORATIVE EFFORT BETWEEN A NUMBER OF FEDERAL AGENCIES INCLUDING NOAA/NWS...U.S. DEPARTMENT OF AGRICULTURE AND THE NATIONAL DROUGHT MITIGATION CENTER. THE OCTOBER 9TH DROUGHT MONITOR SHOWS LITTLE CHANGE IN RECENT WEEKS WITH A CONTINUATION OF EXTREME DROUGHT (D3 CATEGORY) OVER PORTIONS OF SOUTHWEST AND SOUTH CENTRAL IOWA. SEVERE DROUGHT (D2 CATEGORY) COVERS NEARLY THE ENTIRE REMAINDER OF THE DES MOINES HSA WITH ONLY A SMALL AREA OF D1 OR MODERATE DROUGHT IN THE NORTHWEST. IT SHOULD NOTED THAT THE DROUGHT MONITOR DEPICTS GENERALIZED CONDITIONS OVER A LARGE AREA AND MAY NOT REFLECT LOCAL VARIATIONS THAT DIFFER FROM THOSE SHOWN ON THE MAP. DETAILS AND EXPLANATIONS OF THE DROUGHT MONITOR CAN FOUND AT THE WEBSITE (ALL LOWER CASE): HTTP://WWW.DROUGHT.UNL.EDU/DM/MONITOR.HTML PALMER DROUGHT SEVERITY INDEX: THE PALMER DROUGHT SEVERITY INDEX (PDSI) IS ONE OF THE OLDEST AND MOST WIDELY USED MEASURES FOR ASSESSING METEOROLOGICAL DROUGHT IN THE U.S. IT HAS BEEN CALCULATED BACK FOR OVER 100 YEARS AND ALLOWS FOR LONG-TERM DROUGHT COMPARISONS. THE OCTOBER 4TH PDSI MAINTAINS SOUTHWEST AND SOUTH CENTRAL IOWA IN THE SEVERE CATEGORY OF DROUGHT. THE NORTH CENTRAL AND NORTHEAST DISTRICTS HAVE DECLINED TO THE MODERATE CATEGORY. THE CATEGORIES OF THE PDSI ARE AS FOLLOWS: EXTREME DROUGHT : -4.00 OR LESS SEVERE DROUGHT : -3.00 TO -3.99 MODERATE DROUGHT : -2.00 TO -2.99 MILD DROUGHT : -1.00 TO -1.99 NEAR NORMAL : +0.99 TO -0.99 MOIST SPELL : +1.00 TO +1.99 UNUSUAL MOIST SPELL: +2.00 TO +2.99 VERY MOIST : +3.00 TO +3.99 EXTREMELY MOIST : +4.00 OR MORE LATEST (OCTOBER 20) PDSI NUMBERS FOR THE NINE CLIMATE DISTRICTS COVERING ALL OR PORTIONS OF THE DES MOINES HSA ARE AS FOLLOWS: CLIMATE DISTRICT(#) PDSI CATEGORY RAINFALL NEEDED TO BRING PDSI TO -0.5 NORTHWEST (1) : -0.72 NEAR NORMAL NORTH CENTRAL (2): -2.14 MODERATE DROUGHT 4.76 NORTHEAST (3) : -2.18 MODERATE DROUGHT 4.91 WEST CENTRAL (4) : -1.75 MILD DROUGHT 2.67 CENTRAL (5) : -1.66 MILD DROUGHT 2.86 EAST CENTRAL (6) : -1.70 MILD DROUGHT 3.05 SOUTHWEST (7) : -3.95 SEVERE DROUGHT 10.25 SOUTH CENTRAL (8): -3.22 SEVERE DROUGHT 8.09 SOUTHEAST (9) : -1.75 MILD DROUGHT 3.48 ADDITIONAL INFORMATION ON THE PDSI AND OTHER CLIMATE DATA CAN BE VIEWED AT THE NWS CLIMATE PREDICTION CENTER (CPC) WEBSITE AT (ALL LOWER CASE): HTTP://WWW.CPC.NOAA.GOV.PRODUCTS/MONITORING_AND_DATA/US.HTML SOIL MOISTURE CONDITIONS: SOIL MOISTURE MONITORED BY THE CPC AND MIDWEST REGIONAL CLIMATE CENTER (MRCC) CONTINUES TO SHOW WELL BELOW NORMAL LEVELS ACROSS THE ENTIRE AREA. THE CALCULATED SOIL MOISTURE ANOMALY RANKS IN THE 10TH TO 20TH PERCENTILE ACROSS MOST OF THE CENTRAL IOWA REGION. DAILY SOIL MOISTURE MONITORING AND OTHER CLIMATE DATE FOR IOWA IS AVAILABLE AT THE MRCC WEBSITE AT (ALL LOWER CASE): HTTP://MRCC.SWS.UIUC.EDU/ RIVER AND STREAM FLOW CONDITIONS: RIVER AND STREAM LEVELS HAVE FALLEN SLOWLY IN THE PAST TWO WEEKS AND MOST ARE NOW FLOWING BELOW THE 25TH PERCENTILE OF ALL FLOWS FOR TH DATE WITH SOME BELOW THE 10TH PERCENTILE. SOME STREAMS AND RIVERS REMAIN BELOW PROTECTED FLOW LEVELS ESTABLISHED BY THE IOWA DEPARTMENT OF NATURAL RESOURCES. THIS MAY TRIGGER USAGE RESTRICTIONS ON THESE STREAMS. BELOW ARE SOME CURRENT (OCT. 10TH) RIVER AND STREAM FLOWS VERSUS THE LONG TERM MEAN IN CUBIC FEET PER SECOND (CFS). THESE ARE FOR SELECTED RIVERS AND STREAMS IN THE DES MOINES HSA WITH LONG PERIODS OF RECORD (MORE THAN 40 YEARS) AS MEASURED BY THE UNITE STATES GEOLOGICAL SURVEY (USGS). RIVER FLOW LONG-TERM MEAN PERCENT OF (CFS) FOR THIS DATE (CFS) MEAN FLOW WINNEBAGO NR MASON CITY 35 172 20 CEDAR AT WATERLOO 1410 2141 66 IOWA AT MARSHALLTOWN 114 482 24 SOUTH SKUNK ABOVE AMES 10 86 12 DES MOINES NR STRATFORD 160 1129 14 RACCOON NR VAN METER 167 710 24 DES MOINES AT OTTUMWA 343 2995 11 THOMPSON R. NR DAVIS CITY 3 310 1 ADDITIONAL INFORMATION ON STREAMS AND RIVERS MAY BE VIEWED AT THE USGS WEBSITE (ALL LOWER CASE): HTTP://IA.WATERDATA.USGS.GOV/NWIS/RT OUTLOOKS: SHORT-RANGE FORECASTS CONTINUE TO SUGGEST ONLY VERY LIGHT RAINFALL ACROSS IOWA DURING THE NEXT FIVE DAYS. THE 6 TO 10 DAY OUTLOOK FROM THE CLIMATE PREDICTION CENTER (ISSUED 9/25/03) PREDICTS AN ENHANCED PROBABILITY OF ABOVE NORMAL RAINFALL FROM OCTOBER 15TH TO 19TH. FOR THE 8 TO 14 DAY PERIOD FROM OCTOBER 17TH TO 23RD THERE IS ALSO A HIGHER PROBABILITY OF ABOVE NORMAL RAINFALL OVER MOST OF IOWA THE LONG-RANGE CPC FORECASTS FOR THE NEXT 30 AND SUGGESTS EQUAL CHANCES FOR ABOVE...BELOW OR NORMAL RAINFALL ACROSS THE DMX HSA. HOWEVER THE 90 DAY OUTLOOK FOR THE PERIOD FROM OCTOBER THROUGH DECEMBER INDICATES A HIGHER PROBABILITY OF BELOW NORMAL RAINFALL ACROSS MOST OF THE AREA. ALL CPC FORECASTS ARE AVAILABLE ON THE WORLD WIDE WEB AT THE CPC WEBSITE. ADDITIONAL HYDROLOGIC OUTLOOKS WILL BE ISSUED BY THE NWS DES MOINES OFFICE AS THE SITUATION WARRANTS. $$ CORRIGAN