FXUS04 KWBC 191000 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 559 AM EDT SAT JUL 19 2003 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID JUL 20/1200 UTC THRU JUL 22/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... THE SYNOPTIC PATTERN OVR THE NATION WILL REMAIN RELATIVELY STABLE THRU THE PD WITH A HUGE ANTICYCLONE DOMINATING THE WRN HALF OF THE NATION AND A BROAD UPPER TROF OVR THE EAST. BIG PROBLEM FOR THE DAY 1 QPF IS GETTING A HANDLE ON ALL THE LITTLE PERTURBATIONS EMBEDDED IN THIS STABLE PATN. MODEL QPFS WHILE DIFFERING ON DETAILS ARE IN BROAD GNRL AGREEMENT ON PLACEMENT. THE 0600 UTC RUNS WERE LITTLE CHANGED FROM THEIR PREDECESSORS. MOST CHANGES FM THE PRELIM TO THE FINAL DAY1 REFLECT CURRENT OBSERVATIONAL DATA. ...INVOF THE LWR MS VLY... MODEL QPFS ALL POINT TO THE CHANCE FOR WIDESPREAD RAINS HERE. EXPECT A REPEAT OF THE LAST FEW DAYS SCENARIO WHEN SWLY FLOW IMPINGING ON A NW/SE ORIENTED MSTR CNVGNC AXIS INITIATED CNVCTN WHICH WAS THEN ENHANCED UNDER STGLY DIV FLOW ALOFT. ONGOING ACTVTY OVER THE MID/LWR MIS VLY IS EXPECTED TO DROP SWD WHILE CONTG THRU THE MRNG AND INTO THE AFTN HOURS AS CELLS FORM ON THE W SIDE OF THE CNVCTV AREA WHERE MESOSCALE FORCING SHOULD ENHANCE THE LIFTING PROCESS. BIG QUESTION IS WHETHER... WHEN... AND WHERE TO REDVLP ACTVTY LATE SATURDAY NIGHT. WHILE CONFIDENCE IS NOT HI AND MODEL QPFS ARE NIL...THOUGH THE 0600 UTC ETA DID UP AMTS HERE...BELIEVE THE SAME INGREDIENTS WILL BE IN PLACE TO SUPPORT ANOTHER CNVCTV EVENT...THOUGH WEAKER THAN THE LAST FEW DAYS ACTVTY. THE MANUAL QPF FELL BTWN THE WAY OVERDONE GFS BULLSEYE SOLUTION AND WHAT APPEARS TO BE AN UNDERDONE ETA QPF. THE 0600 UTC ETA IN GNRL INCREASED PCPN AMTS IN THIS REGION. ...SE ATLC AND ERN AND CNTRL GULF STATES... ALL FCST MODELS INDC THAT SHRTWV ENERGY WILL BE DIGGING INTO THE BASE OF THE ERN U.S. UPPER TROF AND WILL FIRE CNVCTN ACROSS THIS AREA. WHILE THE ETA AND GFS QPFS ARE IN THE SAME BALLPARK...HAVE LITTLE CONFIDENCE IN PINPOINTING AREAS OF SHWRS AT ANY GIVEN TIME AND HENCE A LOT OF BROAD BRUSHING WAS EMPLOYED HERE. ...NRN PLAINS AND UPPER MS VLY... MODELS BRING A COUPLE OF WEAK SHRTWV ACROSS THIS AREA THAT WILL TAP A WEAK WAA PATN THAT WILL BE IN PLACE HERE. GNLY ACCEPTED THE GFS FOR DETAILS. ...WRN U.S. AND CNTRL PLAINS... THE REMNANTS OF CLAUDETTE WILL CONTINUE TO BE RESPONSIBLE FOR TRIGGERING GNLY LGT AND SCTD SHWRS FM SRN CA NEWD INTO THE CNTRL GREAT BASIN WHERE HIER PWS ARE TRAPPED UNDER THE UPPER HI CELL. ADNL SHWRS ARE EXPECTED FM THE CNTRL ROCKIES SEWD INTO THE PLAINS AS ENERGY EMBEDDED IN NWLY FLOW ALOFT HELPS TO KICK OFF AFTN AND EVNG SHWRS. DAY 2... ...NRN MS VLY/GRTLKS/NEW ENG... MDLS IN MUCH BETTER AGREEMENT THAN THEY WERE DURING LAST NIGHTS DAY 3 PD. THEY AGREE ON A MAX OF PCPN FROM THE NRN MS VLY ESEWD INTO NRN IL AND THE EXTREME SRN GRTLKS. THIS PCPN IS INITIATED IN A SPLIT IN THE UPR PATTERN...THEN SHIFTS EWD W/AN UPR JET MAXIMUM IN THE NRN STREAM. LWRD AMTS FROM THE GFS AND SHIFTED PCPN SW DURING THE EARLY PDS SIMILAR TO THE THE ETA SOLN. LGTR PCPN WL SPREAD EWD INTO NEW ENG...LEANED TWDS THE ETA SOLN AS THE GFS MASS FIELDS HINT THAT THE ETA WOULD BE MORE CORRECT. ...CNTRL PLAINS/GULF COAST/SOUTHEAST... PCPN AT ANOTHER SPLIT IN THE UPR PATTERN SHIFTS SWD FROM AR DOWN THE MS RVR. CONSIDERING THE PWS PRESENT...THE UPR FLOW...AND THE DAY ONE QPF...WENT HEAVIER THAN THE GFS AND SHIFTED ITS AXIS WWD. ANOTHER CONVECTIVE AREA FORMS ALG A WRMFNT IN KS AND SHIFTS ESEWD ACRS MO AND NRN AR BY THE END OF THE PD DUE TO A STRENGTHENING LLJ INTERSECTING THE SFC BNDRY. SHIFTED THE MAX TWDS THE FRONTAL BNDRY...WHICH IS SOUTH OF THE GFS SOLN. ALG THE ERN GULF COAST AND LWR ERN SEABOARD...HIGH PWS IN A SWLY LOW LVL FLOW SHOULD SPONSOR SEA BREEZE CONVECTION. A LOW LVL BNDRY IN THE SOUTHEAST WL ALSO ACT AS A FOCUS...AND THE WRN EXTENT OF SIGNIFICANT PCPN. ...SRN ROCKIES/SRN HIGH PLAINS... AN UPR ACYC IN COMBINATION W/PWS ABOVE AN INCH WL ALLOW DIURNAL CONVECTION TO FORM ACRS THE REGION...MAINLY TO THE LEE OF THE SRN ROCKIES IN NM AND ACRS THE MTS OF SERN AZ AND THE ERN MOGOLLON RIM. WENT LWR THAN THE GFS AS IT HAS A HORRENDOUSLY HIGH BIAS W/CONVECTIVE BULLS EYES IN THE WEST/HIGH PLAINS. DAY 3... ...NEW ENG/GRTLKS... STUNNING AGREEMENT BETWEEN THE MDLS CONSIDERING THE TIME FRAME...WHICH LEADS TO MORE CONFIDENCE IN THE SOLN THIS PD. WHILE THE MAX AMTS FROM THE GFS ARE NOT IN DISPUTE...IT IS BELIEVED THEY ARE SMALL IN SCALE SO THE MANUAL PROGS LOOK A LTL MORE LIKE THE ETA THAN GFS. THE MAX OF 1.50 INCHES WILL STRETCH FROM SRN OH NEWD INTO NEW ENG...INDUCED BY THE RRQ OF A JET STREAK AND A MOIST FLOW PARALLEL TO THE FRONTAL BNDRY. ...SOUTHEAST... USED THE GFS MASS FIELDS TO CONSTRUCT THIS FCST...BUT ITS AREAL AVE AMTS LOOK A BIT HIGH. HALVED THE AMTS ACRS MUCH OF THE AREA EXCEPT NRN FL...WHERE THEY WERE MERELY REARRANGED TO BETTER FIT THE CONVECTIVE SUMMERTIME CONVECTIVE REGIME. ...SOUTHWEST/SRN PLAINS... OTHER THAN TAKING OUT MUCH OF THE PCPN DURING THE CONVECTIVE DOWN TIME...12-18Z...WENT GENERALLY W/THE GFS. A LOW LVL BNDRY WL HELP TO FOCUS ACTIVITY OUT INTO THE SRN HIGH PLAINS TWDS THE END OF THE PD...WHICH BOTH MDLS LATCH ON TO. BELIEVE THE ETA IS RETURNING MOISTURE TOO FAR TO THE WEST ACRS WRN KS AND NEBRASKA. KORTY/ROTH GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 20/12Z 0.01 485681 483675 481673 474674 466679 462685 451700 441715 434729 433733 433738 433747 435752 438756 444758 451757 455754 458749 461742 464736 471720 475711 479703 482695 484686 485681 0.01 534230 535221 535216 531199 527189 521178 518178 517181 515190 517205 518210 517218 515222 510227 507226 502224 493219 490224 492230 493240 486237 481240 479234 474233 472237 475241 477245 479251 483263 492284 497292 501298 507297 511294 0.01 509909 508904 505897 501894 497893 485867 480860 476854 473848 469816 466812 462810 456811 450813 445817 441821 437831 434843 433855 432868 433878 434887 437902 439910 442917 443923 447932 450944 453956 455973 457990 458009 458018 460026 463031 464035 462050 463055 465056 470057 474055 477050 480045 484041 489041 494037 496030 497023 498016 499009 498000 495995 492991 490988 491986 493981 497977 501972 502967 500959 497954 490945 490942 492938 495937 504934 506933 509929 510923 510914 509909 0.01 457106 452060 450058 446060 443061 437062 433060 430057 427049 424042 421033 414018 412013 413007 414996 414990 412985 408977 398969 394969 390971 388974 387979 387985 385989 383992 382990 375987 372989 371993 368001 368012 368016 367021 365025 363027 358033 352036 345040 343042 344048 346055 343062 346070 347072 352075 357073 362075 367079 371085 375090 375095 378100 382101 387100 390101 390106 388109 384109 379110 377113 374121 371125 371131 371143 373146 378147 380152 375155 369153 365151 360152 360156 361158 365164 368167 369169 368172 361172 357178 354181 353185 358188 386206 389206 391202 389193 385186 385183 387180 390177 394176 398173 400167 404163 408167 410172 414176 417179 421178 426174 432168 435165 439163 444158 441141 443131 448120 457106 0.01 393783 388776 381773 376771 374768 373765 372754 370743 369735 366730 362730 358728 354723 351720 347722 345726 343729 341734 333752 328761 323769 312785 302799 298806 295807 291803 283799 275798 266797 257797 253799 250803 250812 252817 255819 263822 278826 285829 287831 287835 287840 289852 288862 283879 282887 281899 283922 279930 278938 277945 278951 281963 276972 275976 275982 281981 289977 296971 302966 314954 320952 324952 334956 342958 352961 360962 368961 372959 375956 380947 381942 382938 381933 380919 378905 377893 377887 373881 371877 367875 362879 357888 351887 350883 346877 345873 343867 342859 344854 346850 348848 353846 360848 366855 369855 371850 376830 380821 383816 386810 392797 394787 393783 0.01 411133 411129 408130 402132 399135 396134 395132 391128 387132 387135 393137 396140 401142 407140 410137 411133 0.01 391161 391157 388160 391161 391161 0.01 365121 361119 357114 349106 345096 338089 335086 332087 330092 322101 321109 323113 326115 334119 342130 346133 350135 352134 353129 353127 356128 362122 365121 0.01 343171 343168 342166 339164 338163 336162 334160 331160 328159 326162 325164 325165 327168 327169 330170 333170 335172 338173 341173 343171 0.25 518273 519269 519265 517259 512251 505239 499237 503248 503252 502257 497255 494251 492247 489244 487246 488254 490261 494272 498281 501285 504286 509285 513281 518273 0.25 461851 461842 459834 455829 452829 450831 447835 445840 444849 444853 445861 448865 452867 457868 460864 461855 461851 0.25 413068 414064 414061 411057 404050 398044 393035 390024 386021 382019 383028 381039 379043 378046 379050 383054 386056 388061 389068 390072 392074 395073 404069 409069 413068 0.25 357755 355747 351742 346746 344752 339765 334775 328785 321795 314803 305812 302818 300823 301836 302852 301865 302878 303893 300904 297909 293914 291919 291926 290940 291948 294950 296951 307946 311944 318941 328945 341949 346949 353949 360947 362945 362941 359936 357932 359928 363925 367923 367920 364915 359910 351904 348900 344891 342886 336881 332878 328873 323861 322853 322849 324846 337826 345803 347798 351792 354787 356780 357767 357759 357755 0.25 286814 284811 280809 276808 272806 269806 266806 261807 261811 264813 267815 271816 275817 278818 284818 286814 0.50 517268 516264 514260 509252 507256 508262 507264 504264 499260 493253 491251 491255 492262 497271 502279 506279 508274 511270 513271 517268 0.50 359920 359916 356914 352912 348910 344907 338900 335895 331890 325886 319876 316872 312870 307872 305877 307891 307897 307903 306907 304913 300921 298925 296931 295941 298944 302944 307942 312939 317937 323939 332943 341945 346946 352944 353942 353939 351934 350929 352925 359920 1.00 346920 340919 331920 326921 320919 314921 312925 310927 306932 309933 313931 319933 325936 331939 337940 343938 343928 346921 346920 1.50 336932 338929 337926 335926 334926 333927 330929 329931 330931 332933 334934 336933 336932 24HR QP VT 21/12Z 0.01 481664 477666 474667 472664 475650 473650 469654 467659 464663 458669 456673 451679 444686 433696 428710 423723 417736 415743 415750 414762 411779 408797 406814 404821 403826 393850 389860 383872 378879 374883 367886 363887 358885 354884 352883 351879 352864 355848 357841 357837 359833 362823 365811 370796 374791 380786 385780 388776 392765 393754 394740 393733 391730 388729 383729 379730 368735 358743 351751 332775 318795 310804 304806 299805 289802 278798 270795 261793 257793 252795 248798 245804 242812 242817 243823 247828 250830 260831 269833 279837 285840 289845 291855 291862 288868 286876 286883 284891 282897 279901 277907 279914 280918 287926 295930 306934 317937 321938 326938 334942 340949 346960 349968 351974 358989 362008 362014 361019 355033 348041 340044 335045 329046 324048 319059 321065 327068 329071 327073 319078 313080 310087 309090 308096 310108 312112 315114 321114 325114 330115 336118 341128 342130 345132 349129 348123 353124 365124 368125 370127 371136 372144 376145 379144 382132 385126 391125 395123 398124 399127 400129 403132 408130 409128 412125 416122 424119 425124 429120 438113 446115 450114 453112 457105 455097 452090 447084 438091 435092 430090 426087 423087 424090 423095 421099 418100 415100 413098 410094 406093 404099 401102 398099 395098 391101 389105 379112 373115 367113 360111 355108 352104 351099 351085 352077 356073 362071 369072 370078 372083 375089 377095 381098 386094 388091 389086 385079 389079 391081 395083 400082 404082 409081 415079 421076 424072 428068 430064 433057 435049 435038 435033 433028 428019 422011 419004 419999 421985 425979 429977 439986 446991 450993 453992 460990 465989 470989 474987 476983 480959 484944 487938 493937 501945 509952 514955 520957 527955 532949 533944 533938 532928 528908 525888 521865 518843 516832 515820 506775 504762 501752 497739 494727 493716 490706 486695 482688 482676 481664 0.01 536191 536185 535181 530174 528169 526166 520162 515155 509149 502146 495140 486134 488142 491150 496155 497159 496167 495173 496177 500179 507183 513190 517195 521206 526209 530204 531196 532193 536191 0.01 519264 520260 518255 513246 504226 500218 497216 491216 489219 487224 492234 485237 483236 481231 478228 474228 471230 469231 469236 471239 475242 483246 488253 493263 497271 503281 506282 507277 507268 512274 515272 518268 519264 519264 0.01 418158 418154 418153 417153 417157 417159 418158 0.01 406217 405212 403208 395200 387195 381189 374183 369181 363181 360181 358184 358188 366193 373198 380204 388212 390215 395218 401219 406217 0.01 409152 409151 406152 403151 401155 403157 406156 409153 409152 0.01 394233 395230 394226 394225 392224 389223 387224 386223 383224 380225 379226 379229 382231 384233 387235 390236 393235 394233 0.01 401140 399139 396139 396140 393140 390141 387141 387142 389146 392149 395148 396147 398145 399143 401140 401140 0.25 516931 517924 516918 512912 509904 504897 494886 486879 480874 475865 472855 470841 470829 472822 472811 471801 468792 464786 454778 443773 442768 443760 443750 443741 441733 439731 434730 430735 428742 428749 427768 418794 416802 413809 411823 409840 406853 402862 400873 399890 398900 397907 394913 391913 388912 378905 373902 367900 361900 353902 350904 346903 341899 320876 313867 311864