FXUS04 KWBC 190704 QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 303 AM EDT SAT JUN 19 2004 PRELIM DAY 1 AND DAY 2 QPF DISCUSSION VALID JUN 20/1200 UTC THRU JUN 21/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... SRN PLAINS/LOWER MS VALLEY... HEAVY RAIN THREAT TO CONT DAY 1 ACRS THE SRN PLAINS FROM SRN OK/NRN TX ALONG THE STNRY FRONTAL BNDRY EXPECTED TO REMAIN ACRS THIS AREA. VERY MOIST SLY TO SELY INFLOW INTO THE BNDRY AND FAVORABLE UPR DIFFLUENCE FROM SHRTWV ENERGY MOVG ALONG THE SRN EDGE OF THE WLYS SHOULD FAVOR CONTINUATION OF PRESENT ORGANIZED CONVECTION...WITH A SLOW SEWD MOVEMENT. THE ETA AND GFS BOTH SUGGEST THAT PCPN POTENTIAL MAY DEVELOP FARTHER TO THE SE TODAY OVR NERN TX AND PUSH SEWD INTO LA IN ASSOC WITH A MAX IN THE LOW LEVEL CONVERGENCE INITIALLY OVR NERN TX THIS AFTERNOON. CONVECTIVE CELL MOTION VECTORS SUGGEST POTENTIAL FOR VERY SLOW MOVEMENT AT THIS TIME...ADDING TO THE HEAVY RAIN THREAT. WITH THE ABUNDANT MOISTURE AND POTENTIAL FOR SLOW MOVEMENT OF CELLS...MANUAL DAY 1 QPF TRENDED TOWARD THE HEAVIER ETA/ETAKF ENSEMBLE MEMBERS..WITH AREAL AVG .75-1.25"+ AMTS FROM N TX SEWD INTO WRN LA CNTRL PLAINS... ORGANIZED CONVECTION MAY ALSO DEVELOP LATE SAT INTO EARLY SUN OVR NERN CO/SERN WY AND PRESS ESEWD INTO SRN NE AND NRN KS ALONG THE DEVELOPING W-E ORIENTED FRONT ACRS THIS REGION. THE ETA AND GFS WERE SIMILAR IN SHOWING STRENGTHENING SELY INFLOW INTO THIS FRONT SAT AFTERNOON...WITH BOTH MODELS ALSO SHOWING WELL DEFINED UPR DIFFLUENCE INVOF NRN KS/SRN NE. ANY CONVECTION THAT DOES DEVELOP WL LIKELY PROGRESS FAIRLY QUICKLY TO THE SE...WITH DAY 1 QPF DEPICTING .50-75" MAX AREAL AVG AMTS ALONG THIS FRONT. NRN ROCKIES/NRN HIGH PLAINS... THE UPR FLOW REMAIN FAIRLY BLOCKED FROM WRN CAN SWD INTO THE PAC NW DURG DAY 1 WITH A CLOSED HIGH INVOF THE AK PANHANDLE/WRN CA AND A DOWNSTREAM CLOSED LOW OVR THE PAC NW/NRN INTERMT REGION. THIS CLOSED LOW WL CONT TO PRODUCE ISENTROPIC LIFT DOWNSTREAM OF IT..WITH COOL WET WEATHER TO CONT OVR THE NRN ROCKIES AND INTO THE NRN HIGH PLAINS. EAST COAST... NRN STREAM HT FALLS PUSHING ACRS SERN CAN/NERN U.S. WL HELP TO ACCELERATE A CDFNT SEWD INTO THE NERN U.S. AND MID ATL DURG SAT. GREATEST RAIN THREAT WL BE OVER NEW ENGLAND AHEAD OF THE STRONGEST UPR DYNAMICS...WITH SOME .25"+ AMTS POSSIBLE FOR NRN ME. SERN U.S... THE ERN FRONT WL BE PRESSING FAIRLY FAR TO THE SOUTH THRU THE SERN U.S. BY THE END OF DAY 1. ABUNDANT MOISTURE AHEAD OF THIS FRONT SHOULD HELP TO FIRE ACTIVE CONVECTION ALONG THE FRONTAL BNDRY FROM ERN NC...SWWD THRU ERN SC AND INTO NRN GA SAT AFTERNOON/EVENING. LOCALLY HVY PCPN AMTS ARE POSSIBLE HERE. DAY 2... GULF COAST/COASTAL SOUTHEAST... A CDFNT WL BE SLIPPING SWD INTO THE SOUTHEAST THIS REGION WITH A PUSH OF DRIER AIR...BUT AREAS NR THE COAST AND ESP ALONG THE IMMEDIATE GULF COAST WL STILL BE EMBEDDED WITHIN A TROPICAL AIRMASS. XPCT THERE TO AGAIN BE PLENTY OF CONVECTION DRIVEN BY DIURNAL HEATING AND THE PRESENCE OF MESOSCALE BNDRYS WHICH SHD HELP PROVIDE A FOCUS. NO SHORTAGE OF MOISTURE EITHER WITH PWS PROGGED ON BOTH THE ETA AND GFS TO BE NR 2.0 INCHES AND LOCALLY HIGHER. THE BEST CONCENTRATION OF CONVECTION SHD BE IN NRN/CENT FL WHERE SEABREEZE CONVERGENCE SHD BE MAXIMIZED. MANUAL PROGS LEAN TWD THE GFS AMTS. THE ETA APPEARS TO BE OVERDONE A BIT IN N FL WITH ITS MAXIMA. NRN PLAINS... XPCT HEIGHT FALLS DROPPING SEWD FRM CANADA TO MOV ACRS THE REGION AND DRIVE A NEW CDFNT SEWD. THIS FRONT WL BE RATHER MOISTURE STARVED AS THE BEST MOISTURE IS TIED UP ALONG A BNDRY IN THE CENT PLAINS AND LWR MS VLY. HOWEVER...SUFFICIENT DYNAMICS EXIST TO GENERATE SOME SCT CONVECTION AND MAINLY DURING THE PD OF MAX HEATING. MANUAL PROGS FAVOR SOME BLENDING OF THE ETA AND GFS WITH THIS. THE UKMET AND CMC SOLNS GENERALLY SUPPORT THE GFS AT THE MASS FIELD LVL...BUT PCPN SEEMS PERHAPS A BIT UNDERDONE ON THE GFS GIVEN THE DYNAMICS/UPR FORCING DROPPING SWD. THE UKMET PCPN ALSO SUPPORT A MORE ACTIVE FRONT DROPPING DOWN LIKE THE ETA. IN ANY CASE...RAINFALL AMTS SHD BE FAIRLY LGT WITH THE FRONT SINCE PWS HERE SHD ONLY BE AROUND 0.75 INCH. CENT PLAINS/MID MS VLY... XPCT A FRONT TO BE STALLED ACR THE REGION INITIALLY WHILE RATHER HIGH PWS REMAIN POOLED ALONG AND JUST S OF THE BNDRY. S/WV ENERGY ASSOC WITH DYING MCS ACTIVITY SHD WEAKEN AS IT PUSHES OUT OF THE PLAINS AND INTO THE LWR MS VLY...EVENTUALLY ENCOUNTERING DRY AIR AND SUBSIDENCE. THEREAFTER THE APPROACH OF NRN STREAM HEIGHT FALLS FRM THE NW SHD BEGIN TO LIFT THE FRONT NWD AS A WMFNT BY LATE IN THE PD. RATHER STG MOISTURE ADVECTION AND INSTABILITY NR THE FRONT AND INTO A REGION OF H25 RRQ JET DYNAMICS AND INCREASING MID LVL SHEAR WL LIKELY HELP INITIATE SOME STG MCS ACTIVITY LATE IN THE PD AND WITH NOCTURNAL LLJ SUPPORT. FEELING THAT THE GFS IS UNDERDONE WITH ITS MAXIMA AND THAT HEAVIER ETA IS MORE REASONABLE GIVEN THE MID/UPR LVL FORCING. RAINFALL AMTS OF 1 TO 2 INCHES ARE POSSIBLE. ORAVEC/ORRISON GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 20/12Z 0.01 507660 505653 502648 497645 493639 488631 482627 477625 466621 460617 456616 443619 437623 434622 432624 428624 427630 426635 427639 429645 431648 433657 434666 433673 427680 423686 420690 416698 414707 416711 420717 422722 425726 426728 430731 434733 440732 456723 467717 481710 494701 497701 500699 503691 506684 507676 507660 0.01 492153 491145 489138 486126 481113 479103 479095 477088 471080 467072 463064 449059 446056 444052 444047 443042 439038 436036 433031 431027 428016 425007 424993 427982 429969 428960 426957 423952 421949 414943 410941 407939 400938 395938 392941 387947 385955 384959 384964 382976 381979 379983 371982 368979 366976 360969 357965 354958 353946 352936 351933 347930 340925 334919 330914 328907 325900 319881 319875 321871 324866 328857 334850 342844 347845 351849 359855 363856 367854 373847 376841 380832 382827 384824 386822 391819 395817 399814 407802 412793 411787 409784 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471143 468137 466129 466120 467115 468109 468103 464099 458097 454093 448089 444088 438088 436092 436096 438106 441111 444116 446122 450123 454122 457123 460127 461134 460139 461144 462152 464158 468161 472160 475159 0.25 427052 427043 427036 423027 416002 412976 411967 409962 407957 403956 400967 400978 397991 393998 389003 389010 394020 395025 394028 391027 389029 385030 385032 388035 395039 399044 402046 409051 416057 420060 424061 427056 427052 0.25 356763 353761 350763 346769 333786 328793 323801 319807 316804 313806 310809 308812 306822 306832 308842 310841 312837 315829 319820 324814 327813 330811 333808 338801 348785 354776 356772 357767 356763 0.25 372022 372014 372007 368999 360985 354978 350970 347961 345951 344948 341942 336937 332930 327924 321919 317912 310898 307886 306879 295886 289892 287900 286908 288914 294934 298943 302948 308955 312962 316969 318976 324994 327002 333008 340012 348013 351016 353020 357026 360034 364034 367033 369030 371025 372022 0.25 359044 358039 355038 347037 341037 332038 327041 322045 319052 320057 324058 333056 338054 346051 352049 358045 359044 0.50 418033 417022 414014 413010 412995 409980 408975 405970 402975 402981 401997 400008 402015 403019 406030 409036 412038 415037 418033 0.50 359002 358995 354989 348979 345972 343968 342959 340952 334942 328933 312918 306908 299901 295901 291903 290908 290912 292916 298929 301940 309949 314958 325982 330994 332000 335004 340007 346008 356005 359002 0.50 343048 341045 339045 338045 335046 335048 335049 338049 341049 343048 1.00 335974 333964 332954 329945 326938 322935 318935 314936 315942 317950 321956 324962 327971 331978 333977 335974 24HR QP VT 21/12Z 0.01 541783 539778 535770 531768 528767 526770 517778 513792 511799 507806 503813 500821 497828 493834 485844 472862 466871 458883 453894 446904 444908 439914 436919 432924 428927 425929 422929 417926 416924 418912 419904 420898 422885 422876 419870 413866 407866 401869 395872 386876 381877 377877 371877 367878 363880 359884 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473091 479107 479114 481120 487123 491121 0.25 546916 547907 546897 544881 540864 536848 531825 530822 527816 523815 518819 514824 512828 509837 507850 504859 501871 499882 499887 501893 503898 505906 507922 507930 510937 516941 520941 525940 534940 538940 540938 543933 544927 546916 0.25 415037 413031 412020 408003 402990 401985 400980 400970 401953 401936 399928 396919 393915 388910 383908 377906 371906 364908 352914 349919 347926 349935 352945 354950 359956 367964 373975 375984 378992 382006 390019 394024 396031 397039 402043 410045 412045 414043 415041 415037 0.25 322816 321811 318810 311810 302810 296809 283805 275802 268801 265801 261804 258809 262814 267818 274822 280824 287827 293831 298838 302844 307851 311851 315843 317835 322820 322816 0.25 323952 323947 321942 319933 316927 312922 306920 303923 301925 299932 297938 297947 301953 306955 314956 318956 322953 323952 0.25 291072 291067 290065 285062 277060 271059 264057 258055 254055 252057 253063 257069 262072 269074 275076 283076 288074 291072 0.50 536899 534885 532871 528857 525849 520846 516853 514861 512871 513884 516897 517911 518918 520922 525922 529921 534914 535903 536899 0.50 396945 396939 394934 391927 387921 380919 368916 359917 355922 354926 354932 357942 360949 365955 373964 376971 379978 383985 389989 393982 395975 396956 396945 0.50 314826 314822 312819 307817 297813 288809 278807 269807 267808 267810 270814 278817 288823 296827 300831 303837 307839 310837 314826 0.50 309945 307942 306941 305943 305946 307947 309945 0.50 281068 280068 277067 275067 272067 269067 268065 266064 264063 263062 261062 260063 261064 262066 264066 266067 268069 269069 272070 275070 277070 280069 281068 1.00 391953 391945 389938 387935 383935 377935 374931 367926 364925 361927 361934 363940 367948 373957 378963 381969 385973 388973 390970 391964 391957 391953 1.50 389953 389950 388946 387943 384947 384951 382954 380952 379951 376950 373951 373953 374954 375956 377959 378959 380963 381964 383966 384967 387966 387965 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