FXUS04 KWBC 190953 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 552 AM EDT WED MAY 19 2004 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID MAY 20/1200 UTC THRU MAY 22/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR ...FINAL DAY 1... 06 UTC MDLS SHOWED NO SGNFCNT CHNGS. DID ADD SOME PCPN ALNG THE RETREATG WRMFNT THRU THE OH VLY TDA AND TWEAKED PCPN OVR THE ERN HALF OF THE NATION DUE TO ONGOING RDR/SATL TRENDS. STILL VRY CONCERNED ABT THE PTNL FOR HVY RNFL FM SERN NEB ACRS IA INTO NRN IL LATER THIS EVE AND TNGT. MDL MASS FIELDS ARE STILL VRY STGLY SUPPORTIVE OF AN E/W TRAING EVENT...BUT THE MDLS STILL ARE NOT PRDCG QPF. SO DID NOT RAISE AMTS AT THIS TIME. ...PRELIM DAY 1... ...SYNOPSIS... THE MIDLVL TROF OVR THE WRN U.S. WL REMAIN IN PLC AS THE VRY HI LAT ERN PAC RDG REMAINS INTACT. SVRL PIECES OF SHRTWV ENERGY WL EJECT FM THE WRN U.S. TROF THRU THE NCNTRL U.S.. THE SCNTRL INTO SERN U.S. WL BE DOMINATED BY A STRNGTHNG MID/UPR LVL RDG. A SFC BNDRY FM THE NRN MID ATLC INTO THE CNTRL PLNS WL BE ONE FOCUS FOR CNVCTN THIS PD. THE WRN END OF THE FNT SHLD LIFT NWD AS A WRM FNT. A SCND FNTL BNDRY WL MOV EWD FM THE NRN ROCKIES ACRS THE NCNTRL U.S. AND SUPPORT PCPN ACRS MUCH OF THE UPR MS VLY/UPR GRT LKS INTO THE MIDWEST/CNTRL PLNS. SCT LGT PCPN IS XPCD OVR THE WRN U.S. IN CONJUNCTION WITH THE DEEP MIDLVL TROF. TRPCL MSTR CAUGHT UNDER THE SERN U.S. RDG WL AGN SUPPORT DIURNAL CNVCTN WITH ISOLD HVY RNS. ...CNTRL APLCHNS/MID ATLC... LATEST WV SATL IMAGERY AND RDR LOOPS SHOW THE SHRTWV OVR THE OH VLY WITH PLENTY OF CNVCTN STILL PROGRESSG SLOLY EWD. THE MIDLVL SYS IS FCST TO CONT MOVG EWD WITH DECENT SYNOPTIC SCALE LIFT AHD OF THE ENERGY. THE SFC BNDRY DRAPED ACRS THE REGION...ALNG WITH SVRL OUTFLOW BNDRYS...WL PROVIDE THE LOLVL FOCUS FOR NUMEROUS RW/TRW TDA ACRS THE REGION. THE MAIN PRBLM WITH BE HEATG AS PLENTY OF DEBRIS CLOUDINESS AND ERLY MRNG CNVCTN WL RESTRICT HEATG SO THAT CAPES WL NOT BE AS HI AS PRVS DAYS. THE MIDLVL LIFT SHLD OVRCOME THIS. THE ONE PLC WHERE WE COULD SEE INCRSG INSTBLTY THIS AFTN IS E OF THE MDL GENERATED LEESIDE TROF THAT FORMS. CAPES IN THIS REGION ARE 1500-2000 J/KG...WHILE CAPES TO THE W REMAIN GNRLY BLO 1000J/KG. THIS MGT HELP TO JUMP THE CNVCTN EWD LATER THIS AFTN TO THE STGR BNDRY LYR MSTR CVRG AND HIER CAPES. PLENTY OF MSTR IS ALRDY IN PLC WITH PWS GNRLY ARND 1.50 INCHES. THIS MSTR WL CONT TO STREAM NEWD FM THE SERN U.S./ERN GULF. XPCT WDSPRD MOD RNS THRU THE REGION WITH ISOLD TWO INCH AMTS WITHIN A COUPLE OF HRS THAT MGT CAUSE LCL RUNOFF PRBLMS. ...SERN U.S... THE MIDLVL VORT THAT'S BEEN WRKG SLOLY EWD IS NOW FCST TO BEGIN TO SHEAR APART AS THE CNTRL U.S. RDG BUILDS NEWD. LATEST WV IMAGERY SHOW THE VORT BECMG ELONGATED FM CNTRL TN INTO THE LWR MS VLY. PLENTY OF DEEP MSTR IS OVR THE REGION WITH PWS AOA 1.50 INCHES. SOUNDGS SHOW VRY WEAK FLOW THRU A DEEP LYR SO STORM MOTIONS WL AGN BE SLOW. XPCT CNVCTN TO FORM ERLY THIS MRNG ALNG THE SEA BREEZE AND OLD OUTFLOW BNDRYS AND XPND INTO THE AFTN HRS AS STG HEATG TAKES PLC. ISOLD TWO INCH RNS WL BE PSBL WITHIN A COUPLE OF HRS. ...MID MS VLY INTO THE OH VLY... THE MCS OVR MO THIS MRNG SHLD WEAKEN AND DRIFT SEWD ALNG/N OF THE SFC BNDRY DRAPED ACRS THE REGION. MDLS SHOW THE LOLVL WAA PTRN BREAKG DOWN ERLY THIS MRNG AS THE FOCUS TURNS BACK TWD THE CNTRL/NRN PLNS. XPCT LCL ONE INCH RNS WITHIN A COUPLE OF HRS AFT 12 UTC. LATER THIS AFTN...STG HEATG NR THE WEAKENG FNTL BNDRY COULD SETOFF CVNCTN BUT WITHOUT ANY MIDLVL SUPPORT THINK THE ACTVTY WL BE VRY ISOLD. ...NRN PLNS TO NRN GRT LKS.... A VRY STG MIDLVL SHRTWV OVR THE NRN HI PLNS WL SHIFT EWD INTO THE UPR MS VLY LATER TDA AND MOV INTO CAN TNGT...THEREBY SUPPORTG A FAST MOVG SFC LOW. THE ASSOCD CDFNT WL PUSH OUT THE ROCKIES THIS MRNG AND ALSO RACE NEWD...BUT TAIL SWWD THRU THE CNTRL PLNS INTO THE CNTRL HI PLNS THIS AFTN. XPCT A SLUG OF ORGANIZED RNFL TO MOV ACRS THE REGION AS THE MDLS SHOW DECENT HGT FALLS AND VRY STG WAA. THE FAST MOTION SHLD LIMIT AMTS TO THE LGT/MOD CAT. ...CNTRL PLNS/MID MS VLY... THE CDFNT DROPG INTO THE CNTRL PLNS WL SLOW ITS SWD PROGRESS TNGT AS IT REACHES THE SRN EDGE OF THE WRLYS AND LOSES MIDLVL HGT FALLS...WHILE THE WRN END OF THE WRM FNTL BNDRY ACRS IL/MO LIFTS NWD. VRY DEEP MSTR S OF THESE BNDRYS WL LIFT NWD WITH THE MDLS SHOWG PWS BLDG TO OVR 1.50 INCHES BY LATER TDA. INCRSG SRLY FLOW WITH STG SFC TO 8H CVRG DVLPS NR THE INTERSECTION OF THE WRM/CDFNTS OVR ERN NEB/WRN IA THIS AFTN. VRY STG SFC BASED INSTBLTY WL DVLP WITH CAPES AOA 4000J/KG THAT COMBINED WITH THE DEEP MSTR AND CVRG SHLD SUPPORT CNVCTN FIRG ALNG THE CDFNT/WRM FNTS DURG THE AFTN HRS. MDLS SHOW THE SFC BNDRYS BCMG ALIGNED WITH THE MIDLVL FLOW AND THE LLJ INCRSG AND VEERG TO A WSWRLY DIR. THIS WL SUPPORT REPEAT ACTVTY DVLPG OVR THE SERN NEB/SWRN IA AND TRAING EWD ALNG/N OF THE WRMFNTL BNDRY. MDLS SHOW STG 8H MSTR TRNSPRT INTO THIS REGION...SOME UPR DVRG AS AN UPR JET STREAK PASSES TO THE N AND A VRY STG 8H THETA-E RDG. ALTHOU MDL MASS FIELDS ARE VRY SUPPORTIVE OF HVY RNS...NEITHER THE ETA/GFS OR NGM SHOW ANY HVY RN. SO...ALTHOU INCRSD AMTS THRU THIS REGION...PLAYED IT CONSERVATIVE DUE TO LACK OF MDL SUPPORT. XPCT A SWATH OF 1-2 INCH RNS ACRS THE REGION WITH ISOLD HVIER AMTS. MGT INCRS AMTS FURTHER WITH THE 06 UTC RUNS. ...NWRN U.S... THE DEEP UPR TROF OVR THE REGION WL SUPPORT MOSTLY DIURNAL RW AND PSBLY TRW OVR A WD AREA. PCPN AMTS WL REMAIN LGT AS MSTR IS LIMITED. DAY 2... MID-WEST/OHIO VALLEY... THE FRONT PUSHING THRU THE GREAT LAKES AND INTO THE NORTHEAST THIS PERIOD WILL ACT AS A FOCUS FOR CONVECTION MOVING THRU THE LAKES AND INTO NEW ENGLAND. THE GFS IS JUST SLIGHTLY FASTER WITH THE BNDRY...AND THUS THE PCPN... AND IS GENERALLY PREFERRED. CONSIDERING THE ABUNDANT MSTR AND STRONG LOW LEVEL INFLOW INTO THE BNDRY... WENT MORE WITH A WETTER ETA-LIKE SOLN... SPEEDING THE TIMING UP SOMEWHAT. LATER ON... AS THE FRONT SINKS SWD THRU THE OH VLY... CONVECTION IS EXPECTED TO FIRE IN THE VICINITY OF THE BNDRY AS A SERIES OF S/WV IMPULSES SLIDE EWD ACROSS THE REGION. THE ETA IS SLIGHTLY FARTHER SOUTH WITH THIS BNDRY THAN IS THE GFS... THUS HAVE GONE MORE WITH THE FARTHER SOUTH AXIS OF THE ETA. SOUTHEAST... THE GFS IS WETTER HERE THAN THE ETA AS MSTR CONTINUES TO FEED UP INTO THE REGION FROM THE ERN GULF. CONSIDERING THE ABUNDANT DEEP LAYERED TROPICAL MSTR PRESENT... WENT MORE WITH THE WETTER GFS SOLN NORTHERN INTERMOUNTAIN REGION... S/WV ENERGY EJECTING EWD FROM THE UPPER TROF OVER THE NW AND GREAT BASIN WILL PRODUCE SOME CONVECTION AT THE HIGHER ELEVS OVER NRN ID AND OVER NWRN WY. OVER THE NRN FRONT RANGE... UPSLOPE FLOW OF MSTR WORKING ITS WAY NWD FROM THE PLAINS. THE ETA IS STRONGER WITH THE SFC HIGH OVER SRN CANADA AND THUS SUPPRESSES SOME OF THE MSTR SWD. DAY3.... WHILE THE AXIS OF THE UPPER TROF OVER THE SW DOES BEGIN TO SHIFT EWD SOMEWHAT THIS PERIOD... THE OVERALL PATTERN REALLY DOESN'T CHANGE MUCH AT ALL.. WITH AN UPPER RIDGE CONTINUING TO DOMINATE THE SERN THIRD OF THE NATION AND SWLY FLOW BRINGING MSTR FROM THE GULF UP THRU THE PLAINS... GREAT LAKES AND NORTHEAST. THIS MSTR WILL FOCUS ALNG THE BNDRY DRAPED THRU THE MIDWEST FUELING MDT TO HVY CONVECTION OVER THE UPPER MIDWEST. WHILE THE GFS SEEMS TO HAVE SOME GRID-SCALE FEEDBACK PROBLEMS OVER WRN WI.. AT LEAST IT IS SIMILAR TO THE ETA WITH THE LOCATION OF ITS MAX. A BIT FARTHER EAST.. THE GFS IS SLIGHTLY FARTHER NORTH WITH THE BNDRY AS THE ETA IS STRONGER WITH THE SFC RIDGE TO THE NORTH. AS WE PREFERRED THE ETA ON DAY2.. WILL CONTINUE WITH THE SAME IDEA ON DAY3... THEREFORE USED THE ETA FOR THE MANUAL QPF. ECKERT/ROBSON GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 20/12Z 0.01 529827 527820 522811 515800 511795 507792 498790 486792 478793 471796 446807 440811 436815 429819 422825 415828 414821 414814 414807 414800 414794 414789 413783 413768 415754 417728 418715 419704 422689 422682 422677 417674 415675 411674 409671 408672 400675 396677 391676 385679 379684 374694 369706 352752 344773 343778 342786 344797 341804 337809 329818 325822 320824 308829 301832 297836 295843 294849 295856 299861 304871 306878 308886 307898 305911 304915 306923 309927 315927 321924 326921 333913 337905 343893 345886 347881 349876 353872 358870 359870 361873 364877 367886 369888 370891 371900 375920 377930 381935 384940 388944 396949 397955 396960 396970 395975 396984 395992 389993 384995 366007 361009 354009 350012 349016 348024 346030 343034 335039 327046 323045 320041 316039 310038 303037 296038 293040 292042 295048 300051 308051 321051 324055 329058 334059 339058 344055 346051 355044 360037 366035 371037 377042 380047 395061 398067 400074 401079 401083 401097 401106 400112 414131 413138 408145 405150 405154 405159 407159 409159 410163 408182 410187 415190 421184 424177 425168 426153 426143 427137 428132 430125 435122 438121 440124 440128 434141 435150 438156 440161 443168 440198 436201 432202 429202 424196 416194 413194 411196 408201 406203 402202 396200 392202 393206 398210 400214 401217 404219 406222 405227 406229 409232 416229 419232 423230 426226 430228 435231 440229 442227 443222 443215 444209 458188 463178 468172 471171 480172 483176 485185 485196 483205 479207 468212 459217 454217 451220 451223 454223 459224 463225 467221 478220 484218 490217 497219 499219 501214 499206 498197 501189 506184 511181 516176 517169 517158 515152 511147 505142 501138 495127 493120 492113 493103 494096 502066 505049 510028 512021 513012 516997 517987 519977 520969 523959 531932 534916 536907 536897 537887 536875 533862 530856 529840 529827 0.01 479024 479015 477007 474994 470991 463991 450991 444993 439995 437998 433999 431004 424012 417022 415026 413031 409045 410049 412052 417055 427058 433058 438060 448064 453067 455074 455084 457089 459093 462090 468080 474051 479024 0.01 444084 441080 436076 430069 424065 420065 416068 414076 412083 413091 415102 421106 425104 426100 425094 427088 433088 437088 441084 444084 0.01 295810 290802 283799 275798 266797 257798 250803 249806 250809 254813 259818 265822 274825 281826 290827 292825 293821 292818 291814 295810 0.25 524884 522875 518871 506868 500866 496862 492854 491851 492849 495845 498839 500831 500822 499817 496814 492811 484813 474817 447830 441834 435838 431842 424848 419854 416860 411873 409879 403884 399877 398871 392855 389849 388841 388834 391827 396824 399821 400818 402802 402787 401772 399755 400742 397728 395719 392715 390715 384715 380718 372730 366741 363748 361754 361760 363767 363775 362781 357792 346816 342822 336827 326834 314840 310843 308845 307849 312855 320861 324867 324871 327877 331878 334876 340866 348858 356853 362854 367857 373857 382854 386867 393881 398887 402889 404899 406910 407920 407926 407945 403962 403978 406989 410993 416994 419998 423998 430990 438983 446980 450977 455977 467980 473981 478985 482989 486997 488007 488018 487026 486036 483056 481064 481069 482074 486078 488077 491074 494068 497059 500046 505026 508009 511988 513969 515950 518931 519919 521905 524891 524884 0.25 484160 482159 479158 476158 474159 476159 479161 481162 484160 0.25 472154 470153 468150 465149 465148 464148 463152 464154 467155 470156 472154 0.25 455176 455172 454169 453167 452166 451167 450171 450175 451177 453178 455176 0.25 389897 389889 386885 382882 379881 377883 376890 376894 376901 377908 378915 380919 384922 386917 387913 387908 389901 389897 0.25 390938 390935 388932 387932 385930 385932 386936 389939 390938 0.50 508977 508948 509928 509913 508896 501887 489879 478879 469884 467895 469912 475925 480935 486944 486951 484957 481963 481968 482975 487983 492993 495006 497013 498020 502014 505005 508992 508977 0.50 408947 408952 408959 410966 414973 419978 423984 426986 434978 437964 443953 451943 459933 453925 445921 437919 433904 436881 437870 439862 439857 438852 435851 432853 426857 423862 419870 413882 410889 408895 408905 409914 409934 408947 0.50 394738 391728 386726 381730 376737 372742 369749 370753 374754 374761 371770 368776 362791 357803 354810 353813 354817 360815 365810 373797 377792 380792 380795 379798 372812 366825 365832 364837 365842 368846 370847 373847 375845 380839 383831 389820 394814 396810 397805 397789 394770 395754 395745 394738 0.50 386898 386894 386891 384888 382888 381888 380888 379893 379894 379896 379900 379904 379907 380911 381914 383917 384914 385910 385906 386902 386900 386898 0.50 357830 355830 352830 350830 347833 346835 346838 349840 350840 352840 352839 354836 355835 356833 357830 1.00 424898 424890 423882 421880 418881 415885 411894 410906 411922 411933 410945 410949 411951 414948 418938 422926 425918 425910 425902 424898 1.50 421915 420907 420903 418898 414895 413899 413904 413913 413923 413933 412944 412946 415943 417935 420922 421915 24HR QP VT 21/12Z 0.01 511678 508670 505662 501652 500648 498643 495639 491638 482644 462662 454673 450680 449685 449693 448701 443714 436727 429737 424743 421745 418747 407746 387747 384747 380745 377738 374730 369720 366715 362716 357717 353723 352727 350738 348742 343745 337750 336754 336767 335773 333779 327789 316805 313809 307815 304818 298819 281816 267811 256810 253811 253814 252822 254829 261833 269837 278841 283844 284848 288856 291864 294881 297885 300892 303907 304913 308914 313914 317913 326900 331893 337887 342878 350869 354865 358863 362866 364874 367882 371885 378885 383884 387886 388895 389902 388910 390924 390938 393944 394949 396958 396967 394976 394979 391985 383991 380993 376996 368002 362009 357014 356016 356020 365026 369028 372029 379028 394027 406025 414025 418026 431028 43