ZCZC OKCHMDTUR TTAA00 KTUR 181640 HYDROMETEOROLOGICAL DISCUSSION NATIONAL WEATHER SERVICE RIVER FORECAST CENTER, TULSA, OK 1130 AM CDT MON AUG 18 1997 ...HEAVY RAINS FALL ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS... ...ANOTHER SIGNIFICANT RAINFALL EVENT IS EXPECTED OVER THE NORTHEAST THIRD OF THE BASIN THROUGH TUESDAY MORNING... ...MODERATE FLOOD POTENTIAL FOR PORTIONS OF NORTH-CENTRAL AND NORTHEAST OKLAHOMA BASED ON TODAYS QPF... ...MODERATE TO HIGH FLASH FLOOD POTENTIAL IN NORTH OKLAHOMA AND SOUTH KANSAS THROUGH 12Z TUESDAY... ...PAST TWENTY-FOUR HOUR PRECIPITATION DISCUSSION... A CONVECTIVE SYSTEM DEVELOPED VERY EARLY THIS MORNING OVER NORTHEAST OKLAHOMA AND PRODUCED HEAVY AMOUNTS OF RAINFALL IN THE SIX HOURS LEADING UP TO 12Z. THE TULSA AREA AND THE AREA AROUND KERR LAKE PICKED UP TWO TO THREE INCHES. DURING THIS SAME TIME...STORMS DEVELOPED IN EAST CENTRAL AND NORTH EAST NEW MEXICO WHERE ISOLATED AMOUNTS OF ONE TO TWO INCHES OCCURRED. TWENTY-FOUR HOUR TOTALS IN THE EASTERN THIRD OF THE BASIN WERE IMPRESSIVEDUE TO THE COMBINED EFFECTS OF THIS MORNINGS SYSTEM AND THE CONVECTIVE COMPLEX THAT DEVELOPED EARLY SUNDAY AND MOVED ACROSS THE SAME AREA. TWENTY-FOUR HOUR (12Z-12Z) TOTALS FOR THESE TWO EVENTS WERE GENERALLY GREATER THAN TWO INCHES OUTLINED BY LINES FROM SKIATOOK OK-FAYETTEVILLE AR- FORT SMITH AR-MCALESTER OK-TULSA OK-SKIATOOK. WITHIN THIS REGION...SOUTH TULSA...FAYETTEVILLE...AND A WIDESPREAD AREA FROM MCALESTER TO MUSKOGEE RECEIVED THREE TO FOUR INCHES WITH A FEW ISOLATED SPOTS GREATER THAN FIVE INCHES. SOME OF THE HIGHER OBSERVED REPORTS INCLUDE (24 HOUR TOTALS): HANNA OK 5.43 STIGLER OK 5.20 TULSA 7SSE OK 4.17 SCIPIO OK 4.00 WHITEFIELD OK 3.97 BIXBY OK 3.87 GORE OK 3.86 CHECOTAH OK 3.62 HASKELL OK 3.37 DUSTIN OK 3.25 TULSA 1SW OK 3.22 TENKILLER FERRY DAM OK 3.09 MC CURTAIN OK 3.05 WEBBERS FALLS OK 3.00 OKTAHA OK 2.89 MUSKOGEE OK 2.75 HUNTSVILLE AR 2.60 COAL HILL AR 2.50 FAYETTEVILLE AR 2.50 SCATTERED SHOWERS ALSO FELL IN NORTH TEXAS SOUTHWEST OF WICHITA FALLS AND IN EAST CENTRAL AND SOUTHEAST COLORADO. AMOUNTS WERE RELATIVELY LIGHT ALTHOUGH RADAR INDICATED SOME SPOTTY AMOUNTS GREATER THAN ONE INCH. ...HYDROLOGIC CONDITIONS... THIS COMBINATION OF HEAVY RAINFALL EVENTS PRODUCED OR IS PRODUCING MODERATE WITHIN-BANK RISES ON SOME OF THE TRIBUTARIES OF THE ARKANSAS RIVER IN NORTHEAST OKLAHOMA. THESE INCLUDE: BIRD CREEK DOWNSTREAM OF BIRCH DAM...THE ILLINOIS RIVER...BIG CABIN CREEK...THE CANEY RIVER AND POLECAT CREEK. HOWEVER...THE HEAVIEST RAINFALL FELL EITHER ALONG THE MAINSTEM OF THE ARKANSAS RIVER OR OVER LAKE EUFALA AND KERR LAKE. COW CREEK NEAR LYONS KANSAS IS FORECAST TO CREST NEAR FLOOD STAGE DUE TO THE HEAVY RAINS FROM EARLY SUNDAY MORNING THAT FELL IN THE NORTHERN PART OF ITS WATERSHED. THE ARKANSAS RIVER FROM NEAR LA JUNTA THROUGH LAS ANIMAS COLORADO REMAINS WITHIN A COUPLE OF FEET OF FLOOD AFTER LAST WEEKS HEAVY RAINFALL BUT RIVER LEVELS CONTINUE TO SLOWLY RECEDE. ...FUTURE HYDROMETEOROLOGICAL CONDITIONS... MODERATE RAINFALL CONTINUES TO FALL FROM NEAR ARKANSAS CITY KANSAS SOUTHEAST TO MUSKOGEE FROM THIS MORNINGS SYSTEM WITH SCATTERED SHOWERS IN WESTERN KANSAS AND THE OKLAHOMA PANHANDLE. THE POTENTIAL FOR ADDITIONAL HEAVY RAINS LATER THIS PERIOD EXISTS. LATITUDINALLY ORIENTED FRONTAL BOUNDARY ACROSS SOUTHERN OKLAHOMA MOVING NORTH...AMPLE MOISTURE...A SHORT WAVE MOVING EASTWARD OVER THE AREA AND A STRENGTHENING LOW LEVEL JET ARE ALL FORECAST FOR LATER TODAY/OVERNIGHT. 24 HOUR QPF FROM WEATHER SERVICE FORECAST OFFICES INDICATES MORE THAN TWO INCHES OF FORECAST RAINFALL ALONG THE KANSAS-OKLAHOMA BORDER AND THEN SOUTH FROM TULSA TO MCALESTER...WITH A 2.50 TO 3.00 INCH MAXIMUM BETWEEN TULSA AND MCALESTER. THE ONE INCH QPF AREA EXTENDS ACROSS SOUTHERN KANSAS AND THE NORTHEAST HALF OF OKLAHOMA. ...FLOOD POTENTIAL OUTLOOK... THIS ADDITIONAL FORECAST RAINFALL IS EXPECTED TO PRODUCE SOME FLOODING IN SOUTH CENTRAL KANSAS AND NORTH CENTRAL AND NORTH EAST OKLAHOMA. THE CHIKASKIA RIVER NEAR CORBIN AND BLACKWELL AND THE SALT FORK OF THE ARKANSAS NEAR TONKAWA ARE FORECAST TO RISE SLIGHTLY ABOVE FLOOD STAGE. THIS QPF ALSO INCREASES THE RISES ON BIRD CREEK NEAR SPERRY AND OWASSO AND POLECAT CREEK NEAR SAPULPA AND BRINGS THEIR FORECAST CRESTS ABOVE FLOOD STAGE. PLEASE REFER TO APPROPRIATE OKCRVF... AFOS PRODUCTS FOR FURTHER INFORMATION. BASED ON TODAYS QPF...THE POTENTIAL FOR RIVER FLOODING IS MODERATE IN THE ABOVE MENTIONED AREAS. ...FLASH FLOOD POTENTIAL... THREE HOUR FLASH FLOOD GUIDANCE VALUES HAVE DROPPED DRAMATICLY AFTER THESE LATEST RAINFALL EVENTS...ESPECIALLY IN EAST OKLAHOMA...WHERE VALUES ARE IN THE 1.50 TO 2.00 INCH RANGE. SOME OF THE GUIDANCE VALUES ALONG THE KANSAS- OKLAHOMA BORDER ALSO DROPPED INTO THE 2.00 TO 2.50 INCH RANGE. BASED ON THE POSSIBLE SCENARIO SETTING UP WITH QPF AND THE SOIL CONDITIONS FROM THE RAINS THAT HAVE ALREADY FALLEN...A HIGH FLASH FLOOD POTENTIAL EXISTS FOR EAST OKLAHOMA AND A MODERATE POTENTIAL EXISTS ALONG THE KANSAS-OKLAHOMA BORDER SOUTHWEST MISSOURI AND NORTHWEST ARKANSAS. ...AREAS WITH A MODERATE TO HIGH RISK OF FLASH FLOODING BASED ON THREE HOUR BASIN FLASH GUIDANCE VALUES (INCHES) AND QPF... SOUTHEAST KANSAS: MODERATE SOUTHCENTRAL KANSAS: MODERATE SOUTHWEST KANSAS: NONE SOUTHWEST MISSOURI: MODERATE NORTHWEST ARKANSAS: MODERATE SOUTHWEST ARKANSAS: NONE NORTHEAST OKLAHOMA: HIGH SOUTHEAST OKLAHOMA: NONE NORTHCENTRAL OKLAHOMA: MODERATE SOUTHCENTRAL OKLAHOMA: NONE SOUTHWEST OKLAHOMA: NONE NORTHWEST OKLAHOMA: MODERATE OKLAHOMA PANHANDLE: NONE PANHANDLE OF TEXAS: NONE NORTH TEXAS: NONE NORTHEAST NEW MEXICO: NONE SOUTHEAST COLORADO: NONE JHP NNNN