FXUS04 KWBC 102231 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 630 PM EDT SAT MAY 10 2003 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID MAY 12/0000 UTC THRU MAY 14/0000 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... UPDATE... THE 18Z ETA SHOWS LITTLE CHG WITH ITS HVY RNFL AREA OVER THE UPR MS VLY AND WRN U.P. OF MI. IT HAS TRENDED SOMEWHAT LIGHTER OVER THE MID MS VLY AND FROM AR/SERN MO INTO THE TN VLY... BUT IMMEDIATELY S OF THIS AREA IT HAS BROUGHT ITS .50 INCH AREA FARTHER SEWD COMPARED TO ITS 12Z RUN. THE GFS IS REASONABLY CONSISTENT WITH ITS 12Z FCST... THOUGH IT HAS INCREASED AMTS OVER THE WRN U.P. OF MI. SIGNIFICANT CHGS FROM PRELIM HPC FCST ARE CONFINED TO THE FIRST FEW HRS OVER THE WV/VA/NC... TO ACCT FOR LATEST RADAR TRENDS. ...ERN HALF OF THE CNTRY... MDLS ARE IN RSNBL AGRMT WITH THE EVOLUTION OF THE CNTRL ROCKIES MLVL CNTR LIFTING NEWD TO THE NRN GTLKS..WITH THE XCPTN THAT THE GFS IS A LITTLE FASTER WITH THE MLVL CNTR AND ASOCTD SFC LOW. THE GFS DOES GET SOME SUPPORT FM THE CANADIAN AND UKMET MDL RUNS..SO ATTM WE ARE LEANING TWD THE GFS SOLN. THE IMPRESSIVE DEEPENING OF THE SFC LOW AND STG HT FALLS/MLVL DYNAMICS SHUD LEAD TO AN EXPANSIVE AREA OF MDT TO HVY OVRRNG RNFL OVR THE UPR MS VLY TO THE NRN GTLKS..WITH THE AXIS OF HVIEST RNFL FM N-CNTRL WI NWD INTO THE CNTRL PTN OF THE U.P. OF MI..WHERE LCL 2 INCH PLUS AMTS ARE PSBL. MEANWHILE..THE TRAILING CDFNT IS FCST TO SWING RAPIDLY EWD FM THE MS VLY TO THE CNTRL-SRN APLCNS AND INTO THE LOWER MS VLY RGN BY THE END OF THE PD. ALTHO THE ETA AND GFS ARE RSNBLY CLS WITH THE TIMING OF THE CDFNT..THE GFS IS FASTER IN PUSHING THE MDT TO HVY PCPN EWD FM THE MS VLY AND THRU THE TN VLY. THE GFS SCENARIO IS PREFERRED..GIVEN THE INCREASED W-SWLY MLVL FLOW. ALSO..THE GFS SOLN IS SUPPORTED BY THE ETAS PW AND FNTL CNVGNC GRIDDED DATA. GIVEN THAT PWS ARE APCHG 2 INCHES ALG/AHD OF THE CDFNT..FNTL CNVGNC IS QUITE STG..ESP DURING THE 1ST HALF OF THE PD AND UPR DIFL IS FCST TO INCREASE IN THE RT ENTRANCE RGN OF A JET SAT NIGHT..FEEL THE HVIER GFS IS MORE CORRECT. FINALLY..OVR THE MID ATLC RGN HAVE ONCE AGAIN GONE WITH THE HVIER GFS QPF. THE GFS SUGGESTS MDT TO HVY RNFL TOTALS FM WV EWD TO THE DELMARVA..WHILE THE ETA HAS GNLY LGT PCPN AMTS FCST FOR THESE AREAS. IT IS RSNBL TO THINK THAT S/WV ENERGY RACING EWD WELL AHD OF THE MAIN MLVL TROF WOULD IGNITE SOME CNVCTN ALG A SLOWLY RETREATING WMFNT..WHICH THE GFS SEEMS TO BE PICKING UP ON QUITE WELL. THEREFORE..HAVE GONE WITH THE GFS QPF HERE. ...PACIFIC NW SEWD INTO THE NRN INTER-MTN REGION... WK S/WV ENERGY UNDERCUTTING THE WRN CANADA UPR RDG WILL TRIGGER WIDELY SCTD CNVCTN FM THE PAC NW CST EWD TO WRN WY AND MT THIS PD. HWVR..IMPULSES WILL BE LACKING MSTR SO PCPN AMTS WILL REMAIN ON THE LGT SIDE. DAY 2... GREAT LAKES... SLOW MOVING UPPER LOW OVER THE GREAT LAKES AND NORTHEAST WILL PRODUCE LT TO MDT SHOWERS OVER THE REGION. ETA AND GFS WERE FAIRLY SIMILAR WITH THE QPF OVER THE AREA THOUGH THE ETA A BIT WETTER. THE ETA IS STRONGER WITH THE STRENGTH OF THE MID-LVL LOW AND THUS DEVELOPS STRONGER LOW LEVEL FLOW OVER THE GREAT LAKES AND IS THUS A BIT HEAVIER OVER SOME OF THE AREAS WHERE TERRAIN EFFECTS DO PRODUCE SOME LIGHT UPSLOPE EFFECTS. DECIDED TO GO WITH SOMETHING OF A COMPROMISE WITH THE QPF AS THE LATEST UKMET IS ALSO SHOWING A COMPROMISE WITH THE STRENGTH OF THE SYSTEM. NRN ROCKIES... A SERIES OF UPPER LEVEL IMPULSES AS WELL AS A WEAK S/WV TROF MOVING THRU THE NRN INTRMTN RGN AND NRN ROCKIES WILL PRODUCE LT PCPN... WITH SNOW AT THE HIER ELEVS. MSTR IS FAIRLY LIMITED.. BUT THE UPPER DYNAMICS ARE STRONG ENOUGH TO PRODUCE BETWEEN A HALF AND AN INCH OF LIQUID EQUIVALENT OVER SOME OF THE ELEVATED TERRAIN. PRETTY MUCH WENT WITH A BLEND HERE OF THE ETA AND GFS... THEN ADJUSTED AGAIN FOR THE TERRAIN. DAY3... ERN LAKES/NE... THE ETA IS STILL A BIT STRONGER WITH THE UPPER LOW OVER THE NORTHEAST THIS PERIOD AS THE GFS IS ALREADY STARTING TO WEAKEN IT AND BEGINS TO MOVE IT TO THE EAST FASTER. THE LATEST UKMET LOOKS MORE LIKE THE ETA IN BEING STRONGER.. THUS HAVE LEANED A BIT MORE TWDS THE ETA WITH THE QPF AS ABUNDANT MSTR CONTINUES TO WRAP BACK AROUND THE MID-LVL CENTER. HEAVIEST PCPN WILL AGAIN BE OVER SOME OF THE ELEVATED TERRAIN WHERE UPSLOPE EFFECTS WILL ENHANCE UVV'S. NRN ROCKIES.... LIGHT PCPN WILL PERSIST OVER MUCH OF THE NRN INTERMOUNTAIN REGION AND GREAT LAKES AS THE S/WV TROF THAT MOVED THRU THE PAC NW ON DAY2 CONTINUES EWD AND INTO THE ROCKIES. AGAIN.. NO MAJOR DIFFERENCES HERE BETWEEN THE ETA AND GFS AND PRETTY MUCH AGAIN WENT WITH A COMPROMISE ADJUSTED FOR TERRAIN EFFECTS. SRN PLNS... ONLY REAL AREA OF CONCERN BETWEEN THE MODELS HERE AS BOTH MODELS BEGIN TO BREAK OUT CONVECTION AGAIN ALONG THE DRY LINE OVER CNTRL TX. GFS IS A BIT WETTER WITH ITS MSTR AND SEEMS TO DEVELOP A BIT MORE QPF.. HOWEVER.. CONFIDENCE IS LOW ENOUGH AT THIS FORECAST TIME TO JUST TRY TO AGAIN COMPROMISE BETWEEN THE TWO AS THERE DOESN'T SEEM TO BE MUCH IN A WAY OF A WELL ORGANIZED FEATURE FOR THE MSTR TO FOCUS ON. RAUSCH/WOLF/ROBSON GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 12/00Z 0.01 521831 517811 515802 512792 498766 493759 486752 477741 468732 463727 459725 442715 431709 427708 421707 408707 402711 398716 395719 392719 389711 382700 377696 373696 368701 366706 364719 362724 360730 358737 357743 356751 356757 356772 347782 336788 333790 328795 321804 315813 313818 311824 311831 310838 309853 306866 302885 297908 295922 293934 291949 287959 283969 282974 281981 281985 284989 288990 292987 297983 301982 307984 309991 314993 319993 326985 333977 339970 348962 356954 367944 377937 382933 387931 391929 395929 397929 399932 404942 405948 404953 402961 402970 402978 402985 402997 403007 405015 409022 411026 417030 421032 425032 432030 435025 435018 436001 437998 441997 445999 454006 460012 466016 471018 475018 479017 483014 487009 490001 493992 496977 499964 503949 503929 504917 507907 512889 516873 518857 521831 0.01 510250 510246 508240 504229 503213 504202 505194 505188 507174 511165 511156 509151 506149 503150 504159 500162 492165 490166 488168 489176 489182 488191 486198 481201 471206 461207 457207 450205 454200 458191 462187 465181 463171 466165 471165 475163 477160 477155 475149 475145 477141 483141 491150 493149 493144 492137 490134 486130 483128 479123 473120 472117 474110 474106 472103 469098 467095 465098 461098 458098 457096 454091 451089 447090 440086 432089 429085 426083 424084 423087 424093 425096 423099 419102 418108 415109 413106 410100 406098 405102 404106 404110 406114 405117 410122 416124 422123 428125 431123 434120 438122 438126 437129 434134 432140 430151 432158 434163 437166 441169 441176 439182 435183 433177 432174 432168 429164 426162 423160 422157 420150 415148 412143 404139 397137 393140 389142 390145 388148 389152 393155 394157 394160 388166 386172 390175 395178 401180 404183 407181 410175 412174 414176 419184 420188 419190 415193 411197 409202 409206 411209 415211 422212 424214 424218 422222 422226 432245 440247 448244 465236 465230 468227 473224 477223 487219 490220 493226 496236 502243 504248 506254 509254 510250 0.01 416072 414070 413067 415065 414060 412056 415053 417049 414048 410049 404050 396049 389048 386050 389054 392056 393058 394064 399068 400073 402072 404071 407075 411075 415073 416072 0.25 507824 504815 499804 494794 489784 481772 474767 469763 461757 456753 449750 435745 427743 420741 411741 403745 398747 394748 389744 385743 380743 376746 373750 366753 361761 360771 361780 362785 364790 368796 368807 365814 355828 345846 334874 328882 325888 321898 319906 316921 314930 318938 317958 318965 320968 322968 324967 326965 334960 340956 351945 363932 369924 375919 382914 388911 398909 406908 412908 417909 420914 422918 428941 428950 427956 428962 431966 436968 443968 448967 453965 459958 468937 473929 477924 487907 492896 496885 500876 504864 506854 507844 507831 507824 0.25 476964 474961 471964 471965 471966 474965 476964 0.25 452188 451184 450183 449183 449187 449188 452188 452188 0.25 454176 454172 451170 450171 450175 451176 453178 454176 0.25 328834 327828 322828 320831 318835 318842 318845 318852 320858 323857 325853 326849 327845 328838 328834 0.25 452222 451221 449221 451222 452222 0.50 370771 369768 367765 366765 363766 362768 361770 361772 361776 362779 363782 366783 367780 368780 369776 369774 370771 0.50 499833 497824 492816 485811 478806 470800 466798 460798 452800 443804 437805 432811 433823 431827 427830 422838 418846 413856 407858 404855 407821 407814 406807 404796 408785 408780 407775 405772 398778 388783 383785 379789 374796 372804 369816 365823 361831 357837 353843 349852 345872 342879 336886 330899 327907 331909 332914 329926 326934 325942 325946 328948 333946 336952 342948 354936 360928 364922 371916 379910 384906 393902 409892 420891 426887 428886 430888 431895 430908 431921 432926 435931 439940 440944 439948 438953 438957 441959 445958 449954 451948 452944 456938 464924 469917 474908 479898 483889 488880 493868 496862 498852 500840 499833 0.50 380881 381877 378875 376879 378882 379882 380881 1.00 485863 483859 478856 476851 476846 476839 475831 472823 469818 464814 461814 458815 457818 456832 455840 454845 451846 445845 441844 434845 428850 424854 422858 425862 429865 435865 444867 446869 447872 447878 444891 441905 441910 441917 445921 448923 452922 459913 467904 472894 478880 485863 1.00 397793 396789 392790 385795 380800 376807 375814 377822 379828 382832 385830 386822 388816 392809 394811 396809 394805 395798 397793 1.00 398879 398873 394870 391874 389878 386886 383888 378891 362899 357903 350912 348918 344925 340932 339942 342943 345941 350933 353928 357920 360916 362913 369907 375902 383898 390893 395885 398879 1.00 377848 376843 373839 369839 365842 360847 357856 352872 350880 347888 340904 338910 337919 338920 342917 346909 349904 356896 360891 365884 370867 373860 376852 377848 1.50 355882 353882 353883 353884 355882 1.50 469834 466821 463822 461828 463852 457857 454857 452855 444851 436851 433854 434855 435858 438859 441860 449860 453861 456866 454876 452886 450895 448907 450911 451910 458903 462900 464897 468887 471877 471872 471864 469852 469838 469834 1.50 367849 366848 365849 366850 367849 2.00 465875 465871 464870 463872 462874 461877 460881 463883 464880 465876 465875 24HR QP VT 13/00Z 0.01 499694 495682 476652 447629 431639 398665 371700 373716 388723 393725 395724 400726 403727 406731 408738 408743 407752 404760 402762 401769 401776 399780 396783 382796 380804 379813 381820 384825 387833 396845 399847 402854 405862 415880 425894 437901 445901 449902 452906 453909 456913 461914 465914 470913 474910 482903 485902 487904 491902 493898 501879 507859 511847 512838 514817 515793 515780 512767 511759 510751 507743 505740 505735 499694 0.01 539132 540120 540106 540102 538097 537092 535087 530078 526072 521068 514064 507064 499064 491064 484062 473054 462045 458041 455034 452024 448017 446015 442012 434013 428017 421021 418026 417034 415042 409049 405053 402056 402060 404064 404068 409076 414077 416076 417072 419071 421076 421079 421085 423097 421103 415109 411108 411103 411098 408096 405098 404103 404109 406113 409119 415124 417126 417130 416136 417142 418150 418159 420162 423165 425171 433175 430180 426184 424186 426188 429188 433184 436183 436186 434197 435202 439205 444208 450201 454195 456189 458185 462183 465176 464171 467168 475170 481175 483178 485183 489189 493194 499194 503192 506193 514197 522198 524198 525194 522189 518181 518178 516172 515170 519172 524176 528175 531171 535159 536151 536142 539132 0.01 517263 515256 512252 510247 509236 506230 502219 500213 496211 494213 494217 495228 497236 501245 506253 510260 516263 517263 0.01 482213 482212 478211 473212 467213 461212 458213 454213 449214 442213 437214 431212 429207 426206 424207 423212 422219 423224 427226 431229 434232 438231 442231 449229 453226 459228 462229 466228 471223 476221 481217 482213 0.01 335800 335794 334791 325787 306795 289802 284804 275803 268803 264806 265809 267811 273814 279820 286823 288826 290832 295855 295873 294881 294891 290910 289918 289922 290928 291930 294932 296931 301927 309914 312908 314903 316897 318891 321881 325863 328847 331829 334813 335805 335800 0.01 341048 335042 324028 321017 314003 309985 306965 305948 301943 298942 293945 283953 278957 274964 273970 275980 277987 276991 274993 269998 269005 271012 270020 273023 280026 282028 282031 279034 279038 280045 285050 296056 311060 327058 336053 341048 0.25 481699 480689 478685 475681 472677 466670 461664 456661 452660 445662 442668 441675 442682 441691 440697 436702 426708 423713 420719 418726 418733 418741 422747 423751 424761 425766 426775 416778 415782 412784 406788 401792 394796 410819 410823 413830 417836 418847 419856 422865 427869 434869 446865 454861 457861 458864 459874 458881 459899 461904 463907 466907 470904 474897 478889 480883 481876 482870 481864 480858 480849 478838 475827 473822 473817 474809 478795 481782 483774 484766 484750 483741 481729 480722 481713 482703 481699 0.25 464131 463130 460128 458126 457126 457128 458131 459135 460135 461135 463135 464131 0.25 454176 454172 452167 452165 451167 450171 450175 451177 453178 454176 0.25 446109 444106 441106 439108 441110 444110 446109 0.25 291996 2889