FXUS04 KWBC 081007 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 505 AM EST SAT FEB 08 2003 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID FEB 09/1200 UTC THRU FEB 11/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR ...06Z UPDATE...LATEST MDL DATA IS VRY SIMILAR TO PREVIOUS RUNS..SO LITTLE CHG WAS MADE TO THE PRELIM DAY 1 QPF... DAY 1... ...SWRN STATES EWD THRU SRN PLAINS/TX AND ALG THE GULF CST... MDLS AGREE S/WV ENERGY DROPPING SWD ON THE FNT SIDE OF THE EPAC UPR RDG WILL KICK A MLVL CNTR AND ACCOMPANYING S/WV ENERGY FM THE SRN CA CST E-SEWD ALG THE U.S.-MEX BORDER TO W- CNTRL TX THIS PD. MDLS ARE INDICATING .5 INCH PWS ASOCTD WITH THE MLVL CNTR. ALTHO THE MSTR IS LIMITED..THERE SHUD BE SUFFICIENT HT FALLS AND STG MLVL DYNAMICS TO SUPPORT AN EXPANSIVE AREA OF LGT TO SPOTTY MDT PCPN AMTS FM NRN BAJA EWD OVR AZ/NM TO NRN TX AND OK/SRN KS. THE HVIEST PCPN IS XPCD OVR THE HIER TERRAIN OF SRN AZ..WHICH WOULD BE JUST TO THE N OF THE S/WV TRACK. MDL QPFS WERE RSNBLY CLS HERE..WITH THE GFS JUST SLIGHTLY HVIER OVR SRN AZ. MEANWHILE FM SRN TX EWD OVR THE SRN GLF CSTL STATES TO FL..THE MDLS ARE IN VRY GOOD AGRMT IN SHEARING A SERIES OF WK S/WVS EWD THRU THE SUB-TRPCL JET. THE S/WV ENERGY AND MSTR MVG THRU THE SRN STREAM WILL OVRRN A FNTL BNDRY THAT HAS BEEN FORCED SWD INTO THE GLF FM A SFC RDG BLDG OVR THE SRN TIER OF STATES. THE DEEPEST MSTR SHUD REMAIN OVR THE GLF THIS PD..SO PCPN AMTS ARE XPCD TO BE GNLY LGT ACRS THIS RGN. MDL QPFS IN GOOD AGRMT HERE. ...NRN/CNTRL ROCKIES EWD INTO THE GTLKS... A COUPLE OF SGFNT S/WVS WILL ROTATE ARND THE MASSIVE PLR VRTX AND INTO THE NRN TIER OF STATES THIS PD..USHERING IN ANOTHER RND OF ARCTIC AIR. HWVR..THESE IMPULSES WILL HAVE VRY LITTLE MSTR ON WHICH TO WRK...SO XPC MOST SNOWFALL AMTS WITH THESE IMPULSES TO BE ON THE LGT SIDE. MDL QPFS IN GOOD AGRMT ACRS THESE AREAS. DAY 2... 06Z UPDATE... THE 06Z ETA RUN HAS TRIED TO ADJUST SOMEWHAT TOWARD THE GFS SOLN OVER THE CNTRL/ERN US BY SUN EVENING... BUT IS STILL QUITE RESTRAINED IN ITS NEWD PROGRESSION OF PCPN E OF THE MS VALLEY. WILL GO WITH PRELIM FCST THAT RELIES PRIMARILY ON THE 00Z GFS. ...CENTRAL/EASTERN US... OVER THE PAST 24 HRS THE GFS AND ETA HAVE DONE LITTLE TO RESOLVE THEIR SIGNIFICANT DIFFS IN MASS FIELD AND QPF FCSTS. THE ECMWF AND UKMET... AND TO A SLIGHTLY LESSER EXTENT THE CANADIAN... SIDE MORE WITH THE GFS SCENARIO OF BRINGING A SRN STREAM SHRTWV INTO THE OH/TN VALLEY BY THE END OF THE PERIOD WITH APPCHG NRN STREAM ENERGY OVER THE UPR MS VALLEY. THE ETA IS FASTER WITH BOTH FEATURES... RESULTING IN A QPF PATTERN THAT KEEPS PCPN AWAY FROM THE MID ATLC THRU THE END OF THE PERIOD. SHORT RANGE ENSEMBLE GUIDANCE STRONGLY SUPPORTS THE ETA SOLN OF KEEPING THE MID ATLC DRY THRU 12Z MON. HOWEVER... GIVEN THE EXPERIENCE OF THE LAST SYSTEM TO IMPACT THE ERN US... THE PRONOUNCED SUBTROPICAL JET... AND BACKING OF FLOW AHEAD OF THE SRN STREAM SHRTWV... THE MORE AGGRESSIVE GFS SOLN STILL SEEMS TO MAKE MORE SENSE. EXPECT APPCH OF THE SRN STREAM SHRTWV ENERGY TO BEGIN ENHANCING RNFL OVER THE LWR MS VALLEY BY LATE SUN... SPREADING NEWD TOWARD NC/VA BY THE END OF THE PERIOD... WITH SOME .50 INCH OR HIGHER VALUES POSSIBLE. FCST RAIN/SNOW LINE IS EXPECTED TO LIE FROM THE S-CNTRL PLAINS TO THE CNTRL MID ATLC. FARTHER S... GFS/UKMET GENERALLY AGREE WITH A BAND OF LIGHTER RNFL ACROSS NRN FL AND SERN US COAST IN ASSOC WITH OVERRUNNING N OF A WARM FRONT LIFTING NWD ACROSS THE FL PENINSULA. FROM THE NRN PLAINS TO GRTLKS... THE MID LVL TROF ROTATING INTO THE REGION FROM SRN CANADA SHOULD SUPPORT LGT SNOWFALL SUN AND SUN NIGHT. COLD NWLY FLOW BEHIND THE ASSOC SFC FRONT SHOULD BRING ABOUT ANOTHER EPISODE OF LAKE EFFECT ACTIVITY OVER THE UPR GRTLKS LATE IN THE PERIOD... WITH THE PREFERRED GFS STARTING IT A LITTLE LATER THAN THE ETA. ...NRN-CNTRL ROCKIES/NRN HIGH PLAINS... SHRTWV ENERGY STREAMING SEWD FROM WRN CANADA WILL SUPPORT CONTINUATION OF LGT SNOWFALL ACROSS THE REGION. SFC FRONT DRAPED ALONG THE ERN SLOPES OF THE ROCKIES MAY HELP TO FOCUS ACTIVITY... WITH A FEW LOCATIONS POTENTIALLY RECEIVING A LITTLE MORE THAN .25 INCH LIQUID. DAY 3... ...EASTERN US... THE GFS CONTINUES TO HAVE REASONABLE SUPPORT FROM THE UKMET WITH THE FCST OF MID LVL FLOW OVER THE ERN US. HOWEVER THE GFS INTENSIFIES SFC LOW PRES MUCH CLOSER TO THE NEW ENG COAST THAN THE UKMET OR OTHER GUIDANCE... A RESULT OF A MORE NRN TRACK OF THE SHRTWV CROSSING THE MID ATLC. WHILE THERE IS LOW CONFIDENCE IN SPECIFIC SHRTWV INTERACTIONS AT THIS TIME FRAME... NRN STREAM SHRTWV POSITIONED OVER THE UPR GRTLKS WOULD SEEM TO BE FAR ENOUGH W TO SUPPORT THE POTENTIAL FOR A MORE WRN DEVELOPMENT CLOSER TO WHAT THE GFS SHOWS. THUS THE MANUAL PROG IS RELATIVELY SIMILAR TO THE 00Z GFS SOLN... GIVING SOME .50-.75 INCH TOTALS TO PARTS OF ERN NEW ENG AND .25-.50 INCH TO THE MID ATLC COAST AND INTERIOR NEW ENG. CURRENT THINKING IS THAT THE GFS IS TOO AGGRESSIVE WITH LOW LVL WARMING OVER THE NRN MID ATLC AND SRN NEW ENG... SO IN THIS AREA WOULD EXPECT A GREATER PERCENTAGE OF PCPN TO BE IN THE FORM OF SNOW THAN THE 00Z GFS SUGGESTS. MEANWHILE... GENERALLY LGT LAKE EFFECT SNOWS SHOULD DECREASE IN COVERAGE DURING THE PERIOD AS WEAK SFC RIDGE BUILDS INTO THE REGION. ...NRN-CNTRL ROCKIES/NRN HIGH PLAINS... EXPECT LITTLE CHANGE IN THE OVERALL PATTERN COMPARED TO THE DAY 2 PERIOD. A MODEST RISE IN HGTS MAY LEAD TO A SLIGHT DECREASE IN COVERAGE/AMTS OF LGT SNOWFALL OVER THE REGION VERSUS THE PRIOR 24 HRS... WITH LESS THAN .20 INCH LIQUID MOST LOCATIONS. WOLF/RAUSCH GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov 24HR QP VT 09/12Z 0.01 486704 483698 479696 474695 470698 464701 461703 459702 454707 447719 441723 438729 432739 427748 409782 400803 392822 389831 384842 381850 378860 374872 369883 365893 360900 356908 353911 349915 341918 334919 325919 314922 305927 302924 302917 301910 301907 303894 306886 311879 314870 315858 317836 317826 318816 318813 316809 312809 310807 310804 309798 307791 304785 300784 292781 288780 284783 282786 281791 278801 275809 273818 274828 276832 277835 277842 277853 275862 274871 273881 273898 273905 275911 278920 278929 276939 271946 263952 254954 251956 248960 250968 255977 263983 270986 276991 282997 285999 288000 297999 302997 305994 311987 316979 319972 322967 327968 330970 334974 337980 337984 339996 340012 339025 337037 335042 332045 326045 320044 317047 311052 306050 302051 302063 303067 305069 308072 310076 310079 308086 305091 301098 299104 298110 298120 300126 303127 313131 322135 336123 341123 346124 351125 355124 357117 355105 355095 359085 362075 365065 367060 370056 373052 372048 369047 365047 361044 360041 359034 360026 362022 366019 370017 376010 378002 378996 379989 377984 375974 375962 376952 379931 382920 385909 388904 389899 391893 396889 398888 401890 400894 401898 400908 402916 401923 403938 404946 406952 411954 415952 419943 421935 420920 423911 443900 447898 451898 458904 462908 465909 468909 479906 482903 484898 488886 489872 487863 485853 483842 484835 486829 492811 493805 494798 496792 496786 497773 494758 493753 491748 487744 480734 483726 485716 486704 0.01 499136 500130 501122 498114 496106 494095 493085 493072 494064 496054 497045 496037 493028 490026 486027 483034 480042 476042 473038 467032 462030 453028 450027 448024 445017 441011 435009 431013 428013 427009 425999 423992 418985 414980 408978 401979 397985 398991 400999 403006 405017 404038 404046 401052 395064 391070 392075 394078 400082 407083 413083 416087 412094 407095 405099 404105 400109 401114 406118 411122 417123 426126 432124 434121 437120 442122 447126 448135 451142 448143 439141 436146 436151 439158 444165 446171 451177 453175 454170 455164 458160 461159 465163 469166 473166 478166 482165 482160 481157 477151 476145 479144 483144 489148 491149 494145 497140 499136 0.01 322171 323168 322166 321164 320161 319161 317157 317157 315155 312154 309153 306155 305155 303158 303158 302161 303163 305165 306165 308166 310168 312169 313170 316172 318173 321172 322171 0.25 342106 343096 341088 334085 331085 330087 327095 321098 318103 317106 318110 320112 323111 326108 329103 332102 338106 342106 0.25 294873 293870 293867 292866 290868 289869 288872 288873 287876 286879 286879 286882 287885 288886 291886 292884 293882 293880 293877 294875 294873 0.25 296960 294956 291955 289957 287959 281962 278963 274966 272970 277973 280973 284972 288971 293967 294964 296960 24HR QP VT 10/12Z 0.01 484687 480677 476673 475668 472664 468660 464658 459663 457666 450676 446688 443697 437704 434708 431714 431718 435719 435721 431724 428726 427730 432734 432736 430739 424740 420742 415745 412753 410753 408749 404742 400737 395733 387729 377728 368729 357733 341740 331747 324754 318765 315777 312782 309783 303784 299783 296782 293781 290782 279789 274793 272797 268805 267811 269817 272831 275844 274851 273860 276868 282876 285883 286895 284909 280919 276928 272936 274946 272955 273962 276967 280969 285970 295971 307970 318968 326969 330971 334974 336978 338983 341992 343998 347003 356009 364014 376018 387022 392024 397027 404034 408038 410038 415034 418029 418021 417012 414999 412996 413991 408982 404972 403969 404968 409966 418967 429969 439970 443974 442977 438991 436998 432003 428007 425012 425019 425024 426028 431044 431049 429052 427054 424054 412053 403050 399051 396052 392055 386061 383071 383077 386081 388083 393086 400086 405083 413080 422076 429076 433080 436085 433088 430088 426090 424097 418103 413106 411106 407102 406106 399114 408121 417126 424129 428127 431124 437120 440120 445126 449139 453145 457150 463160 467164 475167 482166 484164 485160 483153 479149 478146 480146 486147 491151 494151 496149 496144 494140 492135 489129 485124 481116 484119 489121 496127 504136 516148 522152 526151 528149 530147 532142 534134 534126 533121 531116 526105 519094 515089 511085 503074 497062 491045 489041 488036 489030 490024 491015 495001 496994 498989 502977 510959 517945 519939 518927 517918 515910 515904 517897 518864 515851 513843 510834 510827 509815 509808 507799 505788 502768 500761 498756 496752 490737 482732 474738 470746 462769 459775 457778 455775 453770 453762 456748 458740 461736 468723 472716 477709 480704 483698 484687 0.01 443824 441820 437817 433814 430809 427806 425806 422807 419810 417816 417821 415827 414837 419844 423845 428844 430840 430837 429833 431829 438832 441829 443824 0.25 484863 485858 485854 484849 483845 482841 480837 478834 478833 474831 474831 471831 471833 469837 469838 470842 470847 471851 473854 473855 474858 476862 478865 478865 481867 484864 484863 0.25 461068 460064 459062 456060 456059 454060 453060 451064 453068 453068 456069 459070 461068 0.25 389809 389803 387800 384795 382790 380782 378773 374765 370760 367759 365762 358781 354794 350804 341822 335833 330844 325863 318873 316879 316884 313895 309905 306916 306921 307926 306931 304936 299943 298947 300949 304948 314941 322934 329928 333926 341923 346920 351916 355920 355926 356938 359938 361931 363918 362911 358907 357904 359899 362897 367891 370880 373868 375857 378844 383831 389809 0.25 342774 340769 334772 330777 328780 326783 324787 323791 322797 321802 324805 327803 332800 333796 335792 337788 339783 341778 342774 0.25 319803 316800 312800 308802 297803 293808 291812 288823 288836 288842 290849 296859 300861 303859 305857 309845 312835 316825 319814 319803 0.50 367804 363797 360797 359800 357804 357812 357817 353820 348826 345835 340850 338866 330882 331887 335891 340888 345884 352877 354875 355870 358862 360854 362843 364837 365832 365827 362817 366813 367807 367804 0.50 328900 327899 325900 323902 323903 322905 323908 324910 326908 327907 327904 328902 328900 24HR QP VT 11/12Z 0.01 485649 483640 479631 472617 468611 464609 460608 456609 452609 446613 437620 431625 428629 421639 415652 412662 406672 399679 386696 379704 371711 354726 340742 312773 300787 293793 285793 281793 276794 272801 269811 267818 266830 267836 267840 268846 270850 277853 283853 289851 292848 297846 302842 309839 320836 332834 337834 343831 349829 353828 357830 360835 361842 361852 361859 362866 365878 375901 376907 379922 381930 383935 385942 387947 390953 393957 398968 416009 420018 425028 430037 435048 434052 432053 428051 421050 418053 413054 409053 404051 398052 391058 387062 385068 384073 386077 389081 392083 395083 400082 406080 414079 425078 431078 436080 442085 442088 440088 433089 418103 417108 413111 411117 411120 414122 422125 431122 436120 441120 445124 448129 451140 457150 461156 466160 469161 472159 475155 474145 478142 482142 488140 489138 485131 472119 482112 486111 493112 499118 504122 507126 510129 514131 517131 522130 525125 527119 531116 533110 534105 534100 533095 529082 523072 512053 499036 493027 490023 486019 472002 465995 459987 451980 445978 442978 440983 441991 443997 443000 441001 435995 429988 421979 416972 406956 400946 395936 390924 385910 381902 379898 378891 381886 385889 393892 406888 414885 426880 432879 436878 448877 451877 455878 459881 459886 459891 460901 463905 467907 473904 475901 482889 484884 484877 485872 484868 483860 481847 480842 481837 482831 486817 490805 493793 495777 497771 496768 497762 497737 496722 494714 494708 494698 493684 489664 485649 0.01 525188 5261