FXUS04 KWBC 101931 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 330 PM EDT FRI SEP 10 2004 PRELIM DAY 1 AND DAY 2 QPF DISCUSSION VALID SEP 12/0000 UTC THRU SEP 13/0000 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... NO SGFNT DIFFS IN THE LATEST MODELS ACRS THE LOWER 48 DURG DAY 1. PAC NW... MODELS AGREE STRONG NERN PAC HT FALLS WL PUSH INLAND INTO SWRN CAN/PAC NW. PW VALUES EXPECTED TO RISE AND ONSHORE SWLY FLOW IS EXPECTED TO STRENGTHEN SGFNTLY AHEAD OF THESE HT FALLS. THIS SHOULD SUPPORT HVY PCPN (1-2") FOR THE OROGRAPHIC FAVORED REGIONS OF THE WA/NRN OR CASCADES...WWD TO THE NRN OR COAST RANGE/WA COAST RANGE AND OLYMPIC RANGE. INLAND MDT TO HVY PCPN (.50-1") LIKELY OVR FAR NERN WA/NRN ID AND NWRN MT. SERN CA/SRN NV/WRN AZ... SCT SHOWERS MAY CONT INTO FRI NIGHT FROM SERN CA EWD INTO THE SWRN U.S. AHEAD OF WEAK SHRTWV ENERGY ROTATING EWD ON THE TOP SIDE OF THE SWRN RIDGE. MOISTURE REMAINS ABOVE NORMAL ACRS THIS REGION WITH SFC DEWPTS IN THE 60S AND A WELL DEFINED SUB-TROPICAL MOISTURE PLUME EMANATING FROM OFF THE WEST COAST OF MEXICO. SHRTWV ENERGY ACRS THIS REGION IS NOT EXPECTED TO BE AS WELL DEFINED AS THE VORT THAT PUSHED ENEWD LAST NIGHT. STILL...WITH ABOVE NORMAL MOISTURE AND SOME ADDED LIFT FROM SHRTWV ENERGY ALOFT...SCT CONVECTION POSSIBLE ACRS THESE REGIONS. CNTRL PLAINS INTO UPR MS VALLEY/UPR LAKES... THE ABOVE MENTIONED LEAD SHRTWV THAT PUSHED ENEWD OUT OF THE SW AND INTO THE CNTRL ROCKIES LAST NIGHT/EARLY FRI MORNING IS EXPECTED TO CONT TO PUSH ENEWD THRU THE CNTRL PLAINS AND INTO THE MID TO UPR MS VALLEY TONIGHT/EARLY SAT. LIMITED MOISTURE WITH THIS VORT SHOULD PRECLUDE ANY SGFNT PCPN AMTS. AT BEST A FEW HUNDREDTHS MAY FALL AHEAD OF THIS VORT. HEAVIER PCPN POSSIBLE ACRS THE UPR MS VALLEY INTO THE UPR LAKES AHEAD OF A STRONGER AREA OF NRN STREAM HT FALLS FCST TO PUSH EWD. THE GFS CONTS TO BE HEAVIER THAN THE ETA AHEAD OF THESE HT FALLS. IT APPEARS THE GFS IS ALREADY VERIFYING BETTER OVR ND FROM PREV RUNS. ATTM...WE LEANED TOWARD THE HEAVIER GFS AMTS AS THIS DEVELOPING AREA OF PCPN PUSHES EWD ACRS MN...WI AND THE U.P./NRN L.P. OF MI. OVERALL...THE SYSTEM WL REMAIN VERY PROGRESSIVE...WHICH SHOULD KEEP MAX AMTS UNDER .50"...WITH AREAL AVG .10-.25" DEPICTED FROM MN EWD THRU MOST OF WI AND THE U.P./NRN L.P. OF MI. SERN U.S./FLORIDA... MODELS AGREE THAT MOISTURE WL REMAIN ABUNDANT ALONG AND TO THE SOUTH OF THE STNRY FRONT PRESENTLY STRETCHING ALONG SERN COAST...WSWWD ALONG THE GULF COAST. THIS ABUNDANT MOISTURE...WEAK SHRTWVS ALOFT AND COMBINATION OF FRONTAL AND SEA BREEZE CONVERGENCE WL SUPPORT MDT TO HVY PCPN FROM NRN FL...ENEWD ACRS SERN GA AND COASTAL SC/COASTAL NC. DAY 2... ...WEST COAST TO ROCKIES... MID LVL TROF PUSHING SLOWLY INLAND WILL SUPPORT A BAND OF RNFL THAT SHOULD FOCUS UPON FAVORED TERRAIN OVER NERN OR... NRN ID... AND EXTREME WRN MT. MAIN MODEL DIFF HERE IS THAT THE 12Z GFS IS FASTER WITH THE MAIN AREA OF PCPN THAN OTHER GUIDANCE RESULTING IN AMTS ABOUT HALF OF THOSE IN THE ETA. THE 12Z GFS IS A BREAK FROM ITS PREVIOUS RUNS AND ITS MID LVL TROF PROGRESSION DOES NOT APPEAR ANY FASTER THAN OTHER 12Z MDLS. THUS WENT CLOSER TO THE ETA WHICH SHOWS MAX AMTS SLIGHTLY IN EXCESS OF AN INCH. HOWEVER... THINK THE ETA LEAVES TOO MUCH MOISTURE OVER CNTRL OR... SO TRIMMED ITS AMTS THERE. OVER THE PAC NW... THE GFS IS THE ONLY MODEL TO DEPICT A SHRTWV ARRIVING AROUND 18 HRS INTO THE FCST PERIOD. THE GFS SOLN SEEMS STG GIVEN THE SHRTWV POSN BETWEEN THE SYSTEM OVER THE NRN ROCKIES AND A STRONGER FEATURE JUST UPSTREAM FROM THE SHRTWV IN QUESTION. THUS OVER NWRN WA PREFER THE LIGHTER ATMS SHOWN BY THE ETA/UKMET/CANADIAN. MEANWHILE A RIBBON OF SHRTWV ENERGY WILL SUPPORT LGT PCPN OVER THE ERN GRTBASIN AND CNTRL ROCKIES... WITH MOST LOCATIONS SEEING .25 INCH OR LESS. ...SOUTHEAST/MID ATLC... THERE IS SOME DISAGREEMENT REGARDING QPF DISTRIBUTION ALONG THE SFC FRONT FCST TO EXTEND FROM THE SRN MID ATLC COAST SWWD INTO THE NRN GULF OF MEXICO... WITH THE MOST NOTABLE DIFFS BEING THE ETA NOT BRINGING MSTR AS FAR N AS OTHER MDLS OVER THE SRN MID ATLC... AND WIDE SPREAD OF SOLNS ALONG THE CNTRL GULF COAST. THINK A NON-ETA BLEND SHOULD BE BEST OVER THE SRN MID ATLC... AS WEAK SHRTWV APPCHG THE E COAST SHOULD BRING RNFL SOMEWHAT FARTHER NWWD THAN THE ETA SHOWS. USED AN ETA/GFS BLEND ALONG THE CNTRL GULF COAST AS A REASONABLE COMPROMISE BETWEEN THE FARTHER NWWD CANADIAN AND THE RELATIVELY DRY UKMET. ...FLORIDA... WENT CLOSER TO THE GFS FCST WHICH INDICATES A BAND OF MOISTURE SHOULD REACH THE SRN FL PENINSULA AS HRCN IVAN NEARS CUBA LATE IN THE PERIOD. PENDING UPDATE OF THE OFFICIAL TPC/NHC TRACK FOR IVAN... IT APPEARS THAT MOISTURE DIRECTLY ASSOC WITH IVAN SHOULD NOT COME INTO THE PICTURE UNTIL AFTER THE DAY 2 PERIOD. ...GRTLKS/NWRN NEW ENG... RELATIVELY MINOR MODEL DIFFS WITH THE MID LVL TROF AND ASSOC SFC FRONT AFFECTING THE REGION ARGUE FOR A BLEND APPROACH WITH TIMING OF LGT RNFL OVER THE UPR GRTLKS AND EVENTUALLY NEW ENG. WITH DAYTIME HEATING SCT LGT RNFL MAY ALSO DEVELOP ALONG THE SFC FRONT OVER THE LWR GRTLKS LATE SUN. ...S-CNTRL MS VLY/LWR OH VLY... WEAK IMPULSE ORIGINATING FROM THE PLAINS SHOULD SETTLE INTO THE REGION SUN... POSSIBLY ENCOURAGING SCT RNFL LATE SUN. CURRENTLY EXPECT ONLY MODEST LVLS OF DEEP MSTR AND INSTABILITY SO AMTS SHOULD BE LGT. ORAVEC/RAUSCH GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 12/00Z 0.01 540202 539182 537175 534169 531164 526159 521154 517152 506142 498136 489127 485124 481123 478124 473126 469132 468141 466141 463144 460148 454150 451152 448154 447158 446169 445175 441181 438189 437198 438202 441205 449200 465180 470192 471196 469198 466200 446212 443211 440212 435214 426219 425223 426229 426231 422233 419232 414235 414239 415243 420248 431251 439253 445253 449255 454258 460262 465265 476272 480276 484282 490294 493300 498303 503302 507297 514285 517277 521270 523260 524254 527243 530235 540202 0.01 494797 490789 486788 482791 466803 461807 455814 449820 445827 442834 439841 434858 432875 429892 425908 420924 417940 417948 417959 415969 412976 403988 395999 388010 379023 377031 378038 379043 381046 382055 384072 386077 389079 392081 396082 405080 409074 412066 410061 398057 396048 395043 396037 398030 404024 415016 425008 439999 449988 457976 463973 472973 479975 485979 492982 496979 498974 500965 502956 504937 505924 506913 506902 505889 500863 498850 499842 499830 497815 497808 495802 494797 0.01 362745 360735 359732 356729 351729 348730 345733 333742 326749 301784 293793 287795 282795 263797 251797 245799 241803 237812 236817 236821 238826 242829 248826 251823 255825 259830 263839 265846 266854 265863 266869 265875 264885 264892 265896 266898 270898 276898 285896 291889 314853 324836 334818 346798 351787 355778 361760 362750 362745 0.01 371187 372183 372181 370177 369174 370169 373159 374147 374122 374113 372107 370104 366104 364105 360110 354117 348123 343128 336130 330135 326142 325148 326153 330159 341168 352180 355183 358186 368188 371187 0.01 280975 280969 277963 276960 274960 267960 256959 252958 246959 241969 237972 236976 237982 239987 242992 247994 254994 260992 266990 269986 278979 280975 0.25 533210 535199 534193 532185 530180 524171 517162 502149 489134 483131 477131 476134 477138 480141 486149 485156 482156 475157 472160 470164 470168 473172 480181 483185 483191 480196 477200 469205 461209 454214 449218 448221 451225 450230 437238 437243 442246 448248 454248 463250 473254 478257 482260 487264 490268 496277 502285 506287 510284 515274 518268 519258 519249 518244 513232 508221 503211 501205 504202 507203 515211 523217 526218 530216 533210 0.25 491906 489893 485886 479885 472890 468896 466901 464905 464915 469919 476924 481927 486926 490918 491908 491906 0.25 471842 470838 467834 464834 460835 455842 451849 447856 445865 443872 443877 445883 449887 454882 458874 460868 465860 469852 471843 471842 0.25 356752 353748 348749 342756 333768 323783 313795 306801 296804 290805 281806 267805 263806 260808 260812 263816 271832 274841 275847 276867 278878 280881 284883 291876 296870 304858 312845 320832 329818 336805 344790 350774 355761 356756 356752 0.50 531204 530196 528189 525181 521176 517170 514167 511165 502165 497162 490160 483160 479160 475163 475166 478171 482175 489177 495180 500185 509193 519205 523209 526210 530209 531204 0.50 517263 517257 516249 511238 506227 502219 495208 492203 489201 480202 472206 456215 452218 454224 456228 454231 449234 446235 442239 442241 447244 454246 460246 468248 477252 486260 493267 499277 502281 507282 509279 512274 516267 517263 0.50 493244 494240 493238 492234 491233 488231 486229 483229 481231 482235 482236 485235 488236 489238 490239 492244 493244 0.50 495149 494148 493144 492142 490139 489138 486137 485138 486141 487143 488146 490148 491149 494150 495149 0.50 353761 353758 352755 348755 343761 334772 325786 318797 312803 305808 297811 290812 282812 276810 270808 264809 266815 271819 277823 281828 281858 283865 284870 287871 292867 296863 306850 313838 330814 343788 349772 353761 1.00 514262 509249 506240 502238 495223 494219 494216 491211 487208 484207 478208 467213 463216 459220 461226 464229 462231 451237 448238 454242 467244 473246 477248 484251 488252 490257 495260 496259 490243 487243 484244 481240 479234 477231 473230 470228 470225 475222 481222 487223 491223 493224 496231 499237 502238 504244 507249 509255 510261 512263 514262 1.00 346772 343771 341774 338777 334781 333785 329793 322800 316808 309814 301819 292823 289826 288831 289842 288846 290852 294853 299851 305843 310837 316829 320821 329806 338791 343781 346772 1.50 487215 485213 482210 479210 476211 473213 471214 472218 475218 478218 481218 483218 484217 487215 1.50 479243 479239 478238 477234 476233 475233 473235 470235 467234 464234 461237 460237 460238 463240 466240 469240 472241 475242 477244 479243 1.50 301834 300834 298834 296836 296839 296840 299839 301835 301834 24HR QP VT 13/00Z 0.01 496660 494651 491644 487639 484639 482641 479647 476653 471666 464676 460681 458688 453701 441710 439713 441717 444719 443723 439728 438731 440731 445730 449732 448737 437757 433769 432775 432782 435789 439790 441796 441803 441817 442833 444837 444841 444848 444862 445870 447872 449870 454858 458847 463842 468843 472848 475854 479859 483863 487863 492860 496848 499833 500818 504756 505745 505734 504727 502710 499701 498693 496684 495677 495673 496660 0.01 546982 547969 546962 545955 540933 534917 530910 524904 520900 517900 513902 508906 504915 500951 497958 495967 495977 494987 502022 502034 501042 495059 495070 496077 498077 506078 513077 519073 524068 529064 533058 537051 538048 540041 542018 545000 546982 0.01 523257 516246 513242 511233 509224 505216 500209 498206 495205 482205 475208 472210 470214 469219 472223 476223 480223 484224 488226 490229 491235 485234 482233 479230 475226 468231 464230 466222 463219 458215 456213 452213 448213 447209 449204 458191 463187 468182 472178 480177 491184 497190 504196 509199 515204 524217 529222 531224 534225 537220 539207 539195 536186 531173 528165 524159 519154 513150 505146 501141 494127 493117 493113 491109 489108 486109 484108 485101 488094 488085 485084 481083 475085 470089 467094 462101 457101 454096 451093 447093 439092 428086 425086 422088 422093 424099 417103 415099 415093 414086 415079 418075 417070 412065 407065 403066 401068 398069 395068 395065 396058 396053 394052 388050 381048 377048 375050 375056 378057 371059 367061 363064 360064 358064 358067 364069 367075 369082 371090 367096 362097 358100 359104 366107 372110 371116 369119 365120 362124 364127 368131 371136 374142 378145 383147 387147 388143 387138 386131 390126 396125 403128 408130 414128 420125 423126 425128 433120 436116 439115 443116 444123 441130 437137 434144 433154 433165 429187 426195 424205 424215 422220 424225 430232 441228 453226 455227 454231 449234 446236 447240 448242 456244 469246 476251 479257 486269 488274 490277 497287 499291 503294 508295 511293 0.01 424837 423829 419827 418827 416832 415840 415845 414849 414857 413862 415869 418868 421864 422858 422854 422846 423842 424837 0.01 378727 374720 369716 362715 357717 354722 348736 340749 323773 314786 310791 305794 300796 295796 288794 277785 272783 265782 257785 248789 241793 239798 235803 233810 233818 234823 237831 240835 243837 251834 260833 267834 273836 279839 280845 279852 279859 275866 271871 266876 261880 257886 255893 256903 259920 263927 268931 272931 276929 283926 288922 294916 300906 304900 309895 314889 318882 321875 327870 333858 333855 334849 331838 328829 331823 333814 336806 341793 349782 354776 360770 367765 373758 377752 379742 379733 378727 0.01 378871 376860 374857 371857 366861 362867 359873 356881 351894 344906 338918 339923 341925 345925 349924 354919 358913 366902 372888 377875 378871 0.01 266971 266968 263966 257965 251964 249962 246962 241964 236968 233973 232980 234985 241985 248983 253980 260978 264975 266971 0.25 487689 485685 483687 476697 472705 469714 469725 467737 465740 465746 465758 467767 470770 473772 476775 477779 470788 467796 470802 473801 483797 487792 487787 488775 488771 486764 487752 487747 486739 485733 485728 487717 487694 487689 0.25 535984 536974 534965 532950 528937 524931 521929 518930 515936 513943 513950 513960 514979 514993 514002 516010