FXUS04 KWBC 260714 QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 313 AM EDT THU AUG 26 2004 PRELIM DAY 1 QPF DISCUSSION VALID AUG 26/1200 UTC THRU AUG 27/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR ...PRELIM DAY 1... ...SYNOPSIS... A BROAD TROF OVR THE WRN U.S. WL BCM MORE AMPLIFIED THIS PD...BUT REMAIN POS TILTED...WHILE THE SERN/ERN U.S. MID/UPR LVL RDG REMAINS STG. A MIDLVL VORT IS CAUGHT UNDER THE ERN U.S. RDG AND WL REMAIN NRLY STNRY THRU THE PD. THE WRN U.S. TROF IS LOADED WITH SVRL PIECES OF ENERGY THAT WL RACE TWD THE ENE...WHILE A STREAM OF STG UPR WNDS TRANSLATES ACRS THE ROCKIES AND SETS UP FM JAMES BAY SWWD INTO THE CNTRL ROCKIES BY THE END OF THE PD. SFC LOW OVR THE NRN PLNS WL MOV NEWD INTO CAN WITH A STRNGTHNG CDFNT XTNDG SWWD THEN WWD ACRS THE CNTRL PLNS INTO THE ROCKIES/GRT BASIN. ...SERN U.S... THE UPR VORT CAUGHT UNDER THE SERN/ERN U.S. RDG WL MEANDER ARND THE REGION AND LKLY LEND SOME ADDTNL MIDLVL SUPPORT TO CNVCTN THIS AFTN. XPCT MOSTLY SEA BREEZE INITIATION ERLY TDA ALNG THE CSTL AREAS WITH PCPN SPRDG INLAND THIS AFTN AND INCRSG IN STRNGTH. MSTR IS DEEP SO HVY RNFL IS LKLY...BUT WITHOUT A STG SFC FOCUS...THINK IT WL BE VRY ISOLD. ...ERN GRT LKS/OH VLY INTO THE CNTRL GULF CST STS... SFC ANLYS HINTS AT AN OLD BNDRY LYG ACRS FM N TO S ACRS THIS REGION WITH SOME SFC CONFLUENT FLOW. DEEP LYRD MSTR IS PRESENT AND THE MDLS SHOW A WEAK 8H THETA-E RDG THRU THE REGION. SHRTWV ENERGY LIFT NEWD THIS MRNG SHLD WEAK AND ACCEL AS IT MOVS INTO THE ST LWR RVR VLY. XPCT AN AREA OF MORE ORGANIZED LGT/MOD RNFL WITH THIS SYS. ADDTNL CVCNTN SHLD FIRE LATER THIS MRNG INTO THE AFTN TO THE S WITH THE ACTVTY LKLY TO MOV RATHER SLOLY...WHICH SHLD SUPPORT ISOLD HVY RNFL. ...GRT LKS INTO THE MID MS VLY/MIDWEST... THE SFC LOW OVR THE NRN PLNS THIS MRNG WL LIFT NEWD WITH THE ASSOCD CDFNT XTNDG SWWD INTO THE CNTRL ROCKIES. MSTR ALNG/AHD OF THE BNDRY IS ALRDY QUITE PLENTIFUL WITH A BROAD AREA OF 1.25+ INCH PWS. THE ETA IS STGR WITH THE LEAD VORT THAT LIFTS INTO THE NWRN GRT LKS THIS PD...BUT BOTH THE ETA/GFS INDICATE INCRSG LIFT THIS AFTN ALNG THE SFC BNDRY AS STG LATE SUMMER INSOLATION COMBINED WITH INCRSG BNDRY LYR MSTR CNVRG HELPS TO ERODE ANY CAP IN PLC. ETA CAPES ARE QUITE IMPRVS WITH 3-4K J/KG S OF THE BNDRY WITH LIS ARND MINUS 6. XPCT CVNCTN TO FORM SOMEWHERE ACRS NWRN IA AND BUILD NEWD...WHILE THE CNVCTN MOVS TWD THE SE. ALTHOU THIS EVENT SHLD START AS MOSTLY SVR...IT SHLD EVOLVE INTO A HVY RN EVENT TNGT AS THE SFC BNDRY BCMS ALIGNED WITH THE MID/UPR FLOW...THE LLJ INCRSG TO ARND 40 KTS WITH MOD/STG LOLVL THERMAL FORCG AND MSTR TRNSPRT. MDLS ALSO SHLD A STG WSW/ENE ORIENTED 8H THETA-E RDG DVLPG ACRS THE REGION. PWS ARE FCST TO INCRS TO 1.75-2.00 INCHES. PT FCST SNDGS FM THE ETA INDICATE 2-3K J/KG OF ELEVATED CAPE FM SERN IA ACRS NRN IL INTO NRN IN TNGT WITH THE UPR WNDS BCMG QUITE DIFL. BOTH THE ETA/GFS SHOW A WEAK SHRTWV EJECTG EWD ACRS SRN WI TNGT WHICH COULD BE THE NECESSARY MIDLVL FORCG FOR THIS EVENT. THE ONLY NEG IS THE PSTN OF THE UPR JET TO THE N AND NO ASSOCD UPR LVL DVRG. THEREFORE...HAV NOT GONE WITH A LRGR AREA HVIER RNFL AMTS AS OF YET. STILL THINK THE PTNL EXISTS FOR LCL 1-2 INCH RNFL LATER TNGT ACRS THE REGION WITH ISOLD THREE INCH TOTALS BY FRI MRNG. ...NRN PLNS... THE SLOW MOVG MIDLVL VORT OVR THE REGION WL CONT TO STRNGTHN WITH AN AREA OF DEFORMATION THAT SHLD SUPPORT A BROAD AREA OF PERSISTENT LGT/MOD RNFL ACRS THE REGION THAT SHLD SLOLY LIFT INTO CAN TNGT. ...WRN U.S... HGTS WL CONT TO FALL ACRS THE REGIN AS TROFG BCMS STGR AND SHRTWV ENERGY DROPS INTO THE SRN GRT BASIN. MDLS SHOW PERSISTENT WRLY FLOW THRU A DEEP LYR WITH DECENT MSTR ERLY IN THE PD. THIS SHLD RESULT IN OROGRAPHIC PCPN OVR THE REGION. XPCT SOME EXPANSION OF THE PCPN THIS AFTN AS COLD MIDLVL TEMPS SUPPORTS LIS DROPG BLO ZERO IN MANY AREAS. XPCT MSTLY LGT PCPN IN THE MORE FAVORED HIER ELEVS. MDLS INDICATE FRZG LVLS ARND 7-8K FT OVR THE NRN ROCKIES WHICH SHLD SUPPORT SNW IN THE HIEST ELEVS. ...NAME AREA... MARGINAL MSTR AND THE LACK OF MIDLVL SUPPORT SHLD RESULT IN ONLY WDLY SCT TERRAIN INDUCED CNVCTN THIS AFTN/EVE. ECKERT GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 27/12Z 0.01 552893 548864 547850 544835 541824 539816 534808 530802 522793 519790 515787 493783 488777 485774 482773 481772 482768 486760 491745 493738 493729 491720 486714 482713 479714 473716 469720 455733 447739 438747 427758 423763 415770 391784 386787 381791 372798 365802 360804 355802 354794 358780 359773 358763 356759 354757 350753 345754 340757 335764 331766 324779 321785 315791 308795 300798 287797 276795 272793 265793 254795 248799 245803 243808 243812 245819 248823 256829 263832 269833 282835 287836 293841 295846 295851 294867 294875 293881 291887 288892 286901 286906 290913 291922 292932 290938 288949 288956 290961 292962 295961 299959 304952 307945 308939 310928 313921 316916 320912 324912 327914 328921 327927 326936 322950 317960 310972 303982 298986 293992 287002 285008 284013 285018 287022 291026 294027 299026 303023 311016 315008 317002 321996 325986 330974 337960 347930 352917 358906 375884 385880 392881 396891 397901 394911 388926 378972 374982 378990 380004 379014 377024 375032 375043 375047 376052 381057 382060 380063 373061 367061 366063 365065 367068 369074 370081 375088 376091 376096 378100 382099 387096 390099 394104 392109 386111 381113 377117 374122 373128 372137 373143 378148 380156 383157 385155 391150 393149 394144 393135 392131 395128 400129 404129 409125 413123 416127 417130 417134 419135 422135 425131 428123 432120 436119 440121 445125 444130 440133 437139 435146 435153 435156 438162 442170 445174 445179 441183 440189 451196 454195 458189 465181 469179 476180 481185 485191 485196 483198 481200 476201 470204 464205 451211 447211 444214 438218 436225 439227 445229 452226 457227 453231 446233 442233 440236 439239 442241 445244 448244 456245 467248 478252 490259 494261 496260 496253 492240 487234 482231 480227 480224 488227 492232 497240 501247 503248 505247 508240 507229 505220 502210 504205 508206 517211 522214 526217 529214 531214 533210 538203 539197 539189 538184 536180 528164 526159 524151 520139 516124 513115 511104 510098 509087 508070 509060 511049 512044 514038 518030 525016 529007 532998 535989 538975 537959 538954 541949 545939 548931 550920 551909 551898 552893 0.01 473982 472972 469969 463972 458976 454980 450981 445978 436967 430968 428974 422990 418002 416011 414021 414028 415035 418044 421049 426055 429060 429066 427070 426074 426080 430080 430072 432068 436065 441063 446064 450060 448055 445052 441046 438040 438034 441027 446022 460022 464018 465009 467001 469995 473986 473982 0.01 400212 400208 400207 398204 398202 395199 392199 390197 387197 386197 387198 389202 392204 394206 394207 397209 398211 399212 400212 0.01 226059 226063 230069 240079 245083 250086 256090 261096 266099 272101 276099 278097 279093 280090 284087 286084 285075 280069 275064 262056 255054 250051 239040 235036 228032 0.25 408111 410109 409103 408099 407100 406103 405107 405112 408111 0.25 536929 537922 536916 535905 534897 533891 529882 524875 522873 519873 512879 506885 503890 492895 482892 476894 476904 483916 486928 488940 487956 483976 482987 480998 479007 480013 481017 484022 490024 496023 503018 507015 512007 515000 520982 524964 536931 536929 0.25 496839 493824 489816 484811 478810 473811 467814 460816 454814 453800 455781 449772 440773 430785 422792 415798 407804 403806 395812 389818 385823 374839 364845 346853 325862 314871 310877 309881 310889 312891 316890 324886 334882 340881 344882 352882 360879 365875 370869 379858 387855 396854 403860 407866 409871 410882 405899 398916 396932 397945 397954 398960 400969 405968 411969 417970 423965 430959 435956 446952 448949 448946 448939 448935 447928 447921 448916 451908 455901 458894 458884 461879 464876 471868 481863 485857 491852 493849 494844 496839 0.25 494171 492162 488156 484153 481151 477151 474149 471148 469143 466141 459143 457151 458156 461160 466164 470166 475166 481169 486175 492175 494171 0.25 480210 477212 476211 474214 473217 469216 468217 469218 472218 475218 479217 482217 484215 485213 483210 480210 0.25 493144 493139 492139 489136 487134 486134 483133 481131 478130 475133 476137 477139 480140 483142 484143 486145 488147 491147 493144 0.25 444105 442104 440105 437107 435109 435112 438111 442111 444111 446112 447110 445106 444105 0.25 399054 397052 394050 393050 391050 391053 394055 395058 394063 397064 399066 398071 397075 398078 400078 401073 402071 404069 407073 409074 411069 409066 406066 404064 405060 406058 403056 401055 399054 0.25 341775 339774 333777 328785 323792 316799 309805 308808 306817 308822 312825 318823 326818 332810 335803 338792 340783 341775 0.25 252801 251809 254818 259821 265823 273824 285826 294824 293814 286808 278801 275800 269798 260798 255799 252801 0.50 342874 326878 320879 321874 329871 341870 342874 0.50 527932 526919 525913 523909 518905 512909 503925 500931 497941 495960 492969 489979 487987 487995 488001 492006 497007 501004 506999 509994 513985 516974 518965 521956 524948 527937 527932 0.50 485835 482827 479824 476824 467828 462834 458842 456848 454858 456862 460863 468860 476854 481848 484840 485835 0.50 401922 400931 400943 402952 405955 411951 417951 419956 424958 432949 437936 435926 435918 435911 439899 443888 444876 439863 430844 422833 413824 410827 412834 414843 415856 414869 414876 412888 410896 408903 404914 401922 0.50 334797 333795 331795 324806 324811 329808 332801 334797 334797 0.50 263806 270807 273813 265813 258810 257807 263806 1.00 426914 430894 430877 427869 423864 420868 417876 414889 410902 406913 404920 403923 404925 405930 409936 414937 421928 426914 2.00 422894 422899 419907 416905 418897 419889 421888 422894 $$