FXUS04 KWBC 300717 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 316 AM EDT FRI APR 30 2004 PRELIM DAY 1 AND DAY 2 QPF DISCUSSION VALID MAY 01/1200 UTC THRU MAY 02/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... SRN-CNTL PLAINS...MID MS VALLEY....GRT LAKES... FRONTAL BNDRY DRIFTING SEWD ACRS THE GT LAKES AND INTO THE CNTL-SRN PLAINS WILL HAVE WAVES PROPAGATING ALG THE BOUNDARY TO FOCUS ROUNDS OF SHWRS/STORMS. GFS INDICATES 1.25-1.5 INCH PW VALUES ADVECTING NORTHEAST FM OK ACRS MO. AN INCREASE IN CNVTN ALONG THE COLD FRONT IS EXPECTED AS ETA/GFS SHOW LOW LEVEL THETAE RIDGE DVLPG ACRS ERN OK INTO SOUTH MO. BOTH MODELS INTENSIFY THE UPPER LEVEL JET TO 110-130 KT ACRS IA/90-110 KT ACRS EAST KS WITH FAVORABLE RIGHT ENTRANCE REGION BECOMING BETTER DEFINED ACRS SOUTH MO-EAST OK-NORTHEAST TX. THE ETA AND GFS BOTH FCST 2 INCH MAXIMA BU TTHE ETA IS FURTHER SOUTH IN OK AND THE GFS UP IN MO. MANUAL QPF ADJUSTED SLIGHTLY FURTHER EAST TO MATCH THE MOVEMENT OF THE ETA LOW LEVEL BOUNDARY AND AXIS OF INSTABILITY/GREATEST PW VALUES IN ADVANCE OF THE BNDRY. THE MANUAL QPF AXIS OF RAINFALL BETTER MATCHED THE MM5 AND CANADIAN GEM IN PLACING HIGHER AMTS A LITTLE FURTHER EAST INTO AR-SOUTHEAST OK THAN THE ETA AND GFS.. THE GFS SEEMED TO DVLP PCPN TOO DEEP INTO THE COOL AIR ACRS IA..AND THEREFORE MANUAL QPF SHIFTED HEAVIER AMOUNTS A LITTLE FARTHER TO THE SOUTHEAST TWRDS THE BNDRY AND GREATER PW VALUES. THE GFS BEST LIFTED INDICES OF -2 TO -5 IN THE WARM SECTOR SUPPORT SHWRS/STORMS ALG AND ON THE WARM SIDE OF THE BNDRY. GULF COAST..FL.. THE GFS/ETA/UKMET/CANADIAN GEM&GLOBAL MODELS ALL INDICATE A DIURNAL INCREASE IN SHWRS/STORMS ALG THE CENTRAL-EAST GULF COAST. THE GFS FCSTS EXCESSIVE RAINFALL IN SOUTH MS-AL...WITH LIKELY GRIDSCALE FEEDBACK PROBLEMS AS THREE INCHES OF RAIN ENDING AT 00Z ALG THE MS/AL BRDR COINCIDES WITH A HALF INCH MAXIMA OF THE CONVECTIVE COMPONENT OF PRECIP...WITH THIS ANOMANLY OCNTINUING THROUGH 06Z OVER SOUTH AL. THE UKMET AND CANADIAN GLOBAL FCST GENERAL QUARTER TO HALF INCH AMTS OVER SOUTH MS-AL-FL PANHANDLE...WHICH SEEMS REASONABLE GIVEN DIURNAL INSTABILITY AND AVAILABLE 1.5-1.75 INCH PRECIPITABLE WATER VALUES. THE GFS AND ETA FCSTS DIFFER IN THEIR PRECIP DISTRIBUTION ACRS THE PENINSULA. THE GFS APPEARS TO HAVE RIGHT IDEA OF HIGHER MATS IN THE CENTRAL PENINSULA DUE TO MORE PRECIP THAN THE ETA COASTAL CAROLINAS... LOW LEVEL THETA-E ADVECTION OCCURRING ON SOUTH-SOUTHWEST FLOW INCREASES PW VALUES TO ABT 1.75 INCHES IN THE GFS. THE GFS FCSTS HALF AN INCH LIQUID EQUIV ALG COASTAL SC-ADJ NC WITH THE ETA INDICATING A QUARTER INCH AREA. THE UKMET AND CANADIAN GLOBAL AND GEM INDICATE A HALF INCH AREA LIKE THE GFS SO MANUAL QPF WENT WITH THE MAJORITY SOLN. CO... TRACK OF DP LYR CIRC ACRS STATE SHOULD BRING AREA OF FAVORABLE UPR DIVERGENCE ACRS CNTL/ERN CO THE FIRST TWELVE HOURS OF PD. ETA AND GFS BOTH INDICATE A QUARTER TO FOUR TENTHS LIQUID EQUIV SO MANUAL QPF USED A BLEND. THE DEPARTURE OF THE DP LYR LOW AND APPROACH OF LOW-MID LEVEL RIDGE SIGNAL THE END OF THE EVENT THIS EVE. DAY 2... ACTIVE WX ACRS THE ERN CONUS AND SRN PLAINS ON DAY 2 AS H5 TROF IS DOMINANT FEATURE IN THIS REGION. THERE ARE SOME MASS FIELD DIFFS WITH THE ETA BEING MUCH STRONGER WITH A S/WV MOVG THRU TX. THE CAN...GFS AND UKMET ARE WKR ACRS THE SRN PLAINS. GFS DEVELOPS A SFC LOW IN THE TN VLY TWD THE END OF THE PD AND MOVS IT TO THE MID ATLC. NONE OF THE OTHER MDLS HAVE THIS FEATURE. HOWEVER...THE GFS CONTINUES TO HAVE SOME FEEDBACK PROBS IN THE SRN PLAINS AND SERN CONUS AND HAS SEVERAL CLASSIC FEEDBACK SIGNATURES. LLJ STRENGTHENS ACRS THE GLFMEX CST TO AROUND 30 KTS FROM THE S TO SW AND PWS ARE AOA 1.50 INCHES IN THIS AREA. LLJ ALSO INCREASES ACRS THE SERN CONUS AND MID-ATLC BRINGING MORE MOISTURE INTO THIS AREA AS WELL. PWS RISE TO AOA 1.50 INCHES HERE. MDLS HAVE COME INTO BETTER AGREEMENT ON THE TIMING OF THE TROF...BUT DIFFER IN THE DETAILS. SHWRS/TSTMS WILL DEVELOPFROM THE SRN PLAINS TO THE NERN CONUS ON DAY 2. HVY RAIN IS LIKELY WITH SOME OF THE STRONGER STORMS. THE INDIVIDUAL S/WV DETAILS MAKE PINPOINTING THE HVY RAIN AREAS DIFFICULT. THE ETA AND CAN HAVE LESS QPF ACRS HE SRN STATES THAN THE GFS. THE UKMET IS THE DRIEST OF THE MDLS. HAVE OPTED FOR A MDL BLEND...TRENDING AWAY FROM THE GFS QPF FOR THE MAN FCST PROGS. PETERSEN/NIERENBERG GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 01/12Z 0.01 513676 511668 507663 503661 499663 491669 483676 473683 463689 449700 445703 443707 439715 434723 430730 413738 406743 401750 397760 398768 405773 402777 398780 390785 383786 376787 370792 364798 360800 355802 349801 350794 352786 352780 350774 347769 345768 337770 326774 319779 302789 294793 288796 283795 269795 262795 259795 255797 252803 251805 251809 247814 244817 244819 256829 262832 269834 275837 278845 281855 286861 288863 290869 289876 283890 278903 291939 296946 299947 304947 312947 319942 342920 353906 357898 361891 364890 370886 373887 373891 370895 368897 363905 356910 345923 333934 324946 316959 308973 301985 298991 295999 294009 294014 295018 297021 300024 303026 308026 315021 320014 329004 334003 338004 345008 349009 353009 357009 360011 365016 367019 366023 360040 357051 356057 356061 357064 362071 367071 368074 371084 373087 378089 381091 383096 391097 395098 399091 401087 405085 412080 415078 417076 418073 417067 418064 419058 418053 416047 416041 416025 415011 415998 415988 416966 417959 419955 423947 427940 433933 442921 448914 451910 452905 454895 458886 465864 471846 477828 484807 488790 493769 497758 503748 514730 516717 516702 514687 513676 0.01 537868 537861 536856 533844 531841 529839 525838 521843 518850 515857 511863 500871 490881 482892 481896 481900 484904 493910 495915 493921 491928 489938 490945 491951 494961 498968 505976 510980 517979 522977 527971 530965 533958 535950 537939 538923 539911 539903 537892 536881 536871 537868 0.01 526048 528043 528039 525033 522030 517025 513022 510021 504018 500022 499031 502038 505043 508046 512049 517051 523051 526048 0.01 416118 414113 411110 411103 408099 405098 403105 400106 398104 396109 398113 403115 406118 411120 414121 416118 0.25 497701 495698 490696 486697 482701 472709 469713 468717 464727 461738 459749 457756 450773 442790 438798 436802 432807 426812 421814 420814 418811 415808 411806 409805 406806 402809 395815 389820 382827 372832 369832 366830 364819 362814 358814 354816 335823 327824 325822 326819 332812 336805 339795 341787 338784 334783 325788 313799 306805 303808 299810 272804 264805 260808 260811 260819 266824 273827 279831 284836 289842 293850 297858 297864 297868 295877 292892 291901 291909 292914 293919 300923 304922 309920 315914 320906 323899 327883 328874 329868 330864 332861 336859 342859 352857 362854 368852 376852 385853 393851 396854 395858 392870 389878 384887 376901 355925 345936 336948 326962 316975 311983 307990 305998 303001 302006 303013 307016 310013 316008 321002 326996 334991 340990 347991 367988 374985 380985 382992 382999 384013 384018 383023 380032 371049 380061 381065 384068 390074 392075 392068 396061 402054 404045 405030 404015 404008 402003 398997 397989 396983 397972 399961 404943 407935 411928 416920 420915 426909 430905 432900 433891 436880 439868 440864 443859 447852 452843 460826 469807 482771 485760 487750 489740 494729 497713 498703 497701 0.25 436758 433760 432761 434762 436760 436758 0.50 477746 476743 473745 471749 470750 469753 468756 468759 467762 466765 466767 465772 465777 467778 469775 470774 471771 473767 475762 475761 476756 477750 477748 477746 0.50 460794 457793 454794 449799 442809 425828 421833 418838 416843 414849 402870 396879 390889 382898 375906 360923 353932 346941 334958 329967 326978 327982 330984 334984 338983 344982 349983 356981 362980 367978 371975 380967 387958 393949 398940 404928 409918 415909 422899 425885 428872 433862 439851 444838 449827 455814 459803 460794 0.50 409835 409831 407828 405823 401819 398820 396822 390826 387829 383833 380836 379840 380844 385845 389845 395843 400842 406839 409835 0.50 393046 394042 394038 393035 392033 389034 386035 383038 383039 380042 380043 378046 378049 377050 378051 381052 384053 386052 389050 390050 392048 393046 0.50 356827 351825 344827 329831 324832 318830 313829 307826 298820 287818 282818 279820 278822 279827 281829 285831 294839 302848 306853 307856 306859 302871 302884 304900 305904 308904 314901 317895 318889 319883 319874 318859 323854 325853 338852 345850 348845 355835 356827 0.50 335796 333793 332793 329793 327794 324796 322798 321799 320801 318804 316808 317811 317812 320812 323811 326810 328808 330805 332802 333800 334798 335796 0.50 321989 320986 317986 315987 312990 310993 309994 307997 306001 305004 306007 308010 311009 313006 314006 316003 318999 319998 320996 321992 321991 321989 1.00 398910 397906 396904 391905 384906 373916 366922 361927 350940 345946 344950 344955 349953 350955 349957 345964 345970 347975 353974 357972 361970 364967 371964 376961 378959 381955 382951 385943 393927 396919 398910 1.00 338841 337840 335839 334839 331839 328839 327839 325838 322839 319839 317841 317842 317843 319845 321846 323847 324847 327847 330846 333846 335844 338842 338841 1.00 294830 295827 293824 292824 289824 287826 287827 289829 291830 293831 294831 294830 1.00 313003 315000 314997 313996 312997 311000 310001 309004 311005 313003 313003 1.50 369928 367926 364927 362929 360931 359932 357935 354939 351943 352943 348947 354949 356946 359941 360941 363939 365937 366936 368932 369928 1.50 361953 358951 351960 351961 349964 349965 352966 354964 355963 361953 24HR QP VT 02/12Z 0.01 530705 528694 525684 520675 516671 495650 486649 480650 476652 464658 457664 452670 436691 430699 424705 409714 404718 399723 389734 383739 378743 374746 367750 357754 351757 348762 347764 344766 337771 330775 324779 316787 310792 304794 292798 287799 279802 267806 263810 264816 264829 266833 268841 271854 271866 267891 267913 263925 257935 251944 249949 250957 250971 251985 255997 258002 261005 264011 267015 271019 276022 294018 309015 325014 338014 345013 348011 349009 359983 361972 363965 368962 380957 389946 395937 399926 401918 402914 401909 398904 396899 396894 399881 404869 409858 412853 417848 421842 426840 432838 437837 443835 450834 457835 463836 467838 471844 479858 482864 487867 493867 501860 504856 510852 514839 517829 518825 518821 517818 506809 503806 499804 501798 507785 514771 517765 523759 527746 532733 530705 0.01 519269 518256 518244 516239 513235 507226 502219 494213 484211 476213 470219 465226 459234 457237 456240 457244 463248 473252 477255 478257 477262 477266 478272 480276 485284 490287 495289 503289 510286 513283 516277 519269 0.25 522700 521696 520692 516688 512687 509684 507682 499668 489666 484670 481675 479681 474688 469693 463697 454708 436726 427735 416745 396764 390767 383769 374771 365772 355772 350773 343775 332783 316795 303802 290808 284809 279812 277816 278822 283831 291840 299846 302849 305855 306863 307869 306874 303880 294894 287903 279910 276914 274919 271929 269939 265947 264953 263957 261967 262975 264981 267985 272988 274990 277995 280000 282001 295001 300002 308001 324992 332986 337983 340978 345969 348964 352959 359953 367944 372938 377929 378920 378914 377898 379888 384878 398857 403850 410840 414834 415828 420817 425807 431798 437793 441793 443795 446801 448806 450809 456806 459803 461800 462795 458788 459784 460780 464776 469775 475775 479774 485772 488770 491766 494760 498755 503749 508743 513737 517730 520719 522707 522700 0.50 502702 501702 499704 498705 499706 502704 502702 0.50 493709 488711 482713 477718 472722 470724 468728 468733 471738 474743 476745 479742 483737 485733 487728 489723 492721 493718 493716 493713 493709 0.50 445748 444744 441742 437742 433745 423751 416759 409766 404774 400783 396791 391796 386799 382801 378801 374798 372795 373791 374789 372786 366783 359781 355778 350778 343780 334785 320796 301807 291811 286814 283818 284822 288828 295835 300842 307842 313844 316846 319850 320857 320863 318871 315877 307893 304901 299908 289918 279929 279940 276948 270962 268970 267975 267980 270983 273984 280987 284988 289987 296984 301983 307984 311983 316982 323978 330971 338960 343953 351950 357947 360944 366937 371932 373928 373924 371913 370901 369893 370889 373879 376872 379866 390849 394841 396834 400824 406817 412810 417800 425784 431776 440768 444763 445757 445748 1.00 371832 365833 360838 356842 348848 347854 342860 341863 342868 346869 350868 355863 359856 360849 365844 369837 371832 1.00 350792 349788 345785 340787 334790 330794 328798 326801 325806 324808 326811 329812 332813 338812 343809 346808 348805 349801 350796 350792 1.00 357899 356891 353886 346885 342885 337884 331885 321892 314901 309909 303920 298928 292938 288946 283956 281962 279969 280970 282973 285973 296969 314955 320954 325951 332943 334937 338932 341928 347925 350926 355923 358921 358918 356911 355904 357899 1.00 304816 302814 300813 297813 295814 294814 292815 290819 291822 294823 297822 300821 302820 304817 304816 1.50 330906 330903 327902 322905 314914 311918 309924 307929 304933 299936 297941 291951 289955 287958 290961 294956 299953 309948 313945 316940 322931 325927 328925 3