FXUS04 KWBC 022207
QPFPFD
 
QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
606 PM EDT THU OCT 02 2003
 
FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID OCT 04/0000 UTC THRU OCT 06/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 

WITH THE 18Z RUNS IN EXCELLENT AGREEMENT TO THE 12Z RUNS..MADE
ONLY MINOR CHGS TO THE PRELIM DAY 1 QPF.

DAY 1...

GRTLKS...
WENT WETTER...SIMILAR TO THE GFS...AS BOTH MDLS PROPEL GULF
MOISTURE NEWD ON THE HEELS OF A 50 KT H8 JET WITH SIGNIFICANT
DIFFLUENCE NOTED ALOFT AHEAD OF A STRONG H2 VORT LOBE. WITH
SUCH STRONG DYNAMICS AND THE 70 PCT SATURATION THICKNESS
BECOMING EXCEEDED...CONVECTIVE PCPN IS PSBL HERE...SO HIGHER
AMTS MAKE SENSE. THE FLY IN THE OINTMENT IS WHETHER OR NOT
SIGNIFICANT CONVECTION GETS GOING ALG A WRMFNT IN THE SRN
PLAINS. IF THIS WERE TO HAPPEN...WHICH IS NOT EXPECTED...THEN THAT
WOULD LEAD TO THE LOWER ETA AMTS AS THE SRN WRMFNT WOULD
INTERCEPT THE MOISTURE BEFORE IT MOVED NE. CONFIDENCE IN THE
FCST COULD CERTAINLY BE HIGHER...BUT IS AVERAGE ALL THINGS
CONSIDERED.

SOUTHWEST...
AN UPR CYC MOVES EWD THRU THE GREAT BASIN...BRIEFLY TAPPING
MOISTURE FROM THE PAC AND SEA OF CORTEZ/GULF OF CA. WENT MORE
TWDS THE ETA PATTERN AS IT FIT THE TOPOGRAPHY BETTER. INCREASED
AMTS ACRS UT DUE TO THE PRESENCE OF THE UPR CYC...WHICH COULD
LEAD TO SHRA AS DAYTIME HEATING DESTABILIZES THE AIRMASS.

SRN PLAINS...
WENT TWDS THE GFS HERE AS THE ETA LOOKS TOO DRY CONSIDERING
GULF INFLOW AND MOISTURE POOLING NR THE BNDRY. AN UPR VORT
LOBE WL SWING BY...HELPING TO ENHANCE DIFFLUENCE ALOFT. TRIED TO
FOCUS ACTIVITY ALG THE SFC WRMFNT DURING THE 15-00Z TIME FRAME...
WHICH LED TO A SLIGHTLY MORE SWD SOLN THAN EITHER THE ETA OF
GFS.

FL...
LIKED THE GFS HERE AS THE FNT...EVEN AT H8...SHOULD SWEEP THRU THE
SRN PENINSULA AS DEPICTED BY THE BOTH THE GFS AND ETA. KEPT THE
EDGE OF THE 0.01 INCH ISOHYET IN THE MOISTURE GRADIENT.  THOUGHT
THE ETA HAD GONE OVERBOARD DURING THE FINAL PD AS EVEN ITS H8
BNDRY LAY FAIRLY FAR SW OF TAMPA...FEEL IT IS PRODUCING PCPN TOO
FAR INTO THE COOLER AND DRIER AIRMASS. USUALLY...ACTIVITY LIKES TO
FOCUS ALG THE SFC BNDRY DURING THE TIME OF PEAK INSOLATION...
WHICH AT THAT TIME LIES IN THE FL STRAITS.

DAY 2...
THROUGH SATURDAY THERE ARE THREE SYSTEMS OF CONCERN. GREAT
LAKES CIRCULATION IS THE MOST OBVIOUS...BUT WITH THE COLD
AIR...THICKNESS WELL BELOW THE CLIMATE HEAVY PCPN AREA...WE ARE
LOOKING FOR WIDESPREAD LIGHT PCPN...BUT 24 HOUR AMOUNTS LESS
THAN AN INCH. IT IS RARE TO HAVE HEAVY PCPN WITH THICKNESS THIS
LOW. CLIMATALOGICALLY THE PREFERRED THICKNESS FOR HEAVY PCPN IS
557-559. EXPECT LAKE EFFECT PCPN ON THE LEE SIDES AS THE LOW LEVEL
INSTABILITY WILL BE HIGH.

UPPER LOW OVER SW STATES BUT ONLY LIMITED MOISTURE FROM SEA OF
CORTEZ. GFS INDICATES STRONGER VORT INTO NORTHERN CO-UT BY LATE
SATURDAY...AND QPF WILL FAVOR THIS.

BOUNDARY ACROSS FL WITH WEAK MOISTURE CONVERGENCE. IT APPEARS
ETA IS TOO STRONG WITH THIS...INTEND TO TONE IT DOWN
SIGNIFICANTLY.

UPDATE 18Z...
NEW ETA PROMPTED AN INCREASE IN LAKE EFFECT PCPN VCNTY LAKE
MICHIGAN...AND SOME INCREASE SOUTHERN FL. AMOUNTS ARE STILL
SMALL. STILL NOT BUYING THE BULL'S EYE COMING IN FROM THE GLFMEX
TO TAMPA BAY AREA. THAT LOOKS LIKE A POORLY INITIALIZED
CONVECTIVE PROBLEM. 

DAY 3...
BIGGEST DIFFERENCE IN ETA-GFS DAY 3 IS THE SHORT WAVE WHICH THE
GFS SENDS INTO NEW ENGLAND...AND THE 500MB LOW OFF NORTHER CA
WHICH IS A MUCH WEAKER TROUGH IN THE ETA. 

THE S/W INTO NEW ENGLAND GENERATES A SFC LOW IN THE GFS AND
INCREASES THE QPF ASSOCIATED WITH IT. INTERESTINGLY THE ETA DOES
NOT DO THIS BUT SLOWS THE FRONT AND MAINTAINS PCPN AS WELL. THE
NET DIFFERENCE IS SMALL. BOTH MODELS MAINTAIN THE BOUNDARY
LAYER CONVERGENCE ACROSS THE SOUTH AS THE SFC HIGH MOVES INTO
THE NORTHERN PLAINS.

IN THE OTHER DIFFERENCE...PREFER THE GFS SOLUTION FOR THE NW
STATES AND WILL BRING SOME PCPN INTO OREGON. GFS HAS BEEN MORE
RELIABLE THAN ETA WITH DAY 3 FEATURES FROM THE PACIFIC.

ROTH/TERRY/KELLY

GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV
24HR QP VT 04/00Z
 0.01 510679 508671 505665 501660 494654 488652 475647 467647 
      460648 448648 440649 434651 429658 426665 426673 430682 
      438687 444688 450689 452693 450697 442705 438711 438716 
      439721 438730 438735 435741 432743 431746 434759 437762 
      441756 444748 450741 458735 468729 473727 477723 476718 
      475713 469694 476700 482703 494708 499708 503704 506700 
      508696 510690 510686 510679 
 0.01 415939 422933 428939 431945 438956 443957 449953 457951 
      464954 474955 480953 488950 493949 510937 520928 527918 
      530902 533882 532851 530821 528787 521761 512748 501741 
      491738 483737 477737 466739 444765 425791 417803 410814 
      403826 394840 386852 365874 353881 344888 339896 339909 
      340926 343943 351965 355982 356992 355000 354009 352014 
      348020 344023 340028 338035 336045 333053 330058 325061 
      320065 317072 315089 315109 316114 320115 327112 332115 
      337122 340127 344132 349137 354140 362142 369143 372147 
      375151 378156 380164 381169 383171 386173 391174 398173 
      401174 407179 412180 416178 420171 422166 421160 421150 
      423138 425131 427127 432121 436116 441110 442105 440102 
      431091 427086 423085 422091 421100 419102 416101 414098 
      414093 415084 418076 424072 430072 439074 439069 438067 
      434060 429055 423051 418046 416041 414040 401038 394035 
      391032 389027 389022 390010 392992 394973 398959 402951 
      407946 415939 
 0.01 272797 270791 264791 258794 252798 247803 244809 243816 
      245825 250834 260845 264848 267847 269842 269835 269824 
      270811 272800 272797 
 0.25 490671 487668 484666 480664 476662 472661 468661 462662 
      460667 463672 468675 472677 475679 479681 483683 487682 
      490679 491675 490671 
 0.25 457913 465905 471903 478906 487911 494910 496903 496894 
      497882 498873 497859 496844 496831 495809 491791 488786 
      486783 479778 474775 468775 463776 458780 452787 448794 
      441808 436818 432824 420835 415843 412850 410858 408868 
      407877 408883 409888 411892 414894 420899 427902 432906 
      444914 448915 452915 457913 
 0.25 398121 395097 398090 398086 398078 396072 393068 389065 
      381059 369042 366040 363042 358052 356066 354071 351075 
      346077 340076 334076 330080 328086 328093 332103 338110 
      346117 354124 358126 365127 374130 381132 388131 393127 
      398121 
 0.25 381966 381959 380952 376942 371932 366923 364919 361916 
      358917 356921 356932 358944 361955 365965 367971 370975 
      373978 376977 379974 381966 
 0.50 484848 481830 478816 471802 464800 454806 446820 439836 
      435842 423853 416863 420872 427876 435880 442885 451892 
      458895 466891 470886 481880 487876 485859 484848 
 0.50 384069 379064 372060 369060 365063 364069 364087 365094 
      371095 375093 381087 386080 386073 384069 
 0.50 348103 348099 347096 346094 345092 344091 341089 338089 
      335090 334092 334095 334099 335100 337102 338103 340105 
      343105 346104 348103  
 
24HR QP VT 05/00Z
 0.01 534733 532721 528709 523694 519687 515682 513676 511672 
      506666 504663 500660 498657 495656 491652 485649 481648 
      478650 472651 464654 456658 449661 441666 434671 427678 
      424682 422685 419694 415710 412727 409742 407750 404758 
      396772 392779 388786 378797 374803 372812 371827 370839 
      371847 373854 375860 375879 375884 377888 381893 385894 
      389895 396891 402886 407881 414877 421875 429876 436878 
      442881 448886 452890 456896 461903 466910 472915 480919 
      487919 493919 499917 505913 509909 513908 518901 522895 
      527884 531874 533869 533865 533852 534843 536819 537797 
      537770 537752 534733 
 0.01 457245 457240 455237 446235 440235 434237 425235 421235 
      418236 418240 421242 426247 429250 431255 434258 439259 
      443259 447258 452253 456248 457245 
 0.01 433212 434209 434205 433201 433200 431197 428195 425194 
      422194 419194 416195 415196 413199 414204 415205 417208 
      418208 420210 423213 425214 428214 431214 433212 
 0.01 363724 362720 359719 348724 344725 345723 348711 349704 
      347699 342701 332707 324714 321716 317715 309715 305717 
      301720 296727 285743 282750 279760 275766 270772 256786 
      246798 243806 243811 245817 274825 278820 282812 286804 
      292797 297792 308785 324776 333774 343770 350766 354762 
      357759 361751 363741 364732 363724 
 0.01 416118 417102 417092 416081 414067 411059 407053 379014 
      372008 361005 360991 361984 362973 362969 362961 360951 
      359943 356938 350934 346937 343943 341953 340957 341962 
      343971 344980 345990 345998 344006 342010 339012 333023 
      330027 329033 325048 294075 298082 301086 306089 315095 
      325102 333107 337111 340115 345125 350131 355135 359137 
      365139 373139 380138 385137 388135 390131 393131 399134 
      402135 405134 409128 412122 416118 
 0.25 529791 523780 517759 511740 504726 497716 491702 483686 
      480683 474680 466678 457677 452677 446678 441682 438685 
      436691 436696 438712 438718 437724 431735 425746 420756 
      413767 407776 401786 396796 396810 398818 402824 408831 
      416839 423846 427851 431859 437856 446860 455862 459865 
      463872 466875 468876 470874 472868 475867 486870 490870 
      497868 502866 505863 510856 512851 515844 517835 520822 
      523804 529791 
 0.25 403098 405092 405084 404076 405068 404063 402058 399054 
      395051 387046 381039 377032 373029 368026 360025 355025 
      349027 347029 344033 342037 341044 342050 344057 349065 
      358079 365086 372091 388101 391104 397104 403098 
 0.25 325750 325747 323743 318737 314735 308734 304736 300739 
      294749 294754 291761 286770 285775 285778 290782 295780 
      305775 311771 315766 323757 325750 
 0.50 508823 507819 507814 505810 503808 500809 498812 497815 
      496817 495820 495825 495826 495830 496832 497834 499834 
      502833 505831 506829 507827 508823 
 0.50 488752 488744 484738 476732 459731 454734 449738 439748 
      428765 418782 413792 410802 411809 414816 422820 429823 
      439824 444823 449820 457812 464803 469793 474783 482774 
      484770 486764 488752 
 0.50 466862 465858 464857 464858 465862 466863 466862 
 0.50 399091 397083 398076 399070 399064 394061 389061 383065 
      380066 375065 371065 369068 372075 378082 384085 388090 
      392094 396095 398094 399091 
 0.50 375047 375043 375041 374039 372037 371036 369035 366035 
      363036 363037 361040 361042 360044 359047 359051 361054 
      364056 367056 369055 370054 372052 373050 375048 375047 
 0.50 314753 312750 311750 308751 306752 304754 304755 302758 
      302759 301763 304763 307763 309761 311759 313757 313756 
      314753  
 
24HR QP VT 06/00Z
 0.01 528723 521701 515681 512673 510669 510663 507660 505656 
      502648 499642 495640 486636 478633 474632 469629 464625 
      459623 455623 450625 445629 441635 436645 431658 429663 
      426667 423673 419677 413681 408684 402685 396688 391692 
      386697 381705 375716 370724 367729 362732 340746 334755 
      330765 330769 331776 335782 337784 342783 344780 349771 
      354764 360761 364761 370762 373760 376757 378754 381752 
      383755 386760 390761 394763 392767 381784 370802 364812 
      362819 362824 362831 364838 367845 370848 373849 374852 
      376859 379862 381863 384861 388854 392845 398832 401822 
      405811 407809 410811 412815 414821 413827 414838 413845 
      410848 409854 408861 410866 413870 417874 423878 431876 
      442876 452876 456878 459883 461887 462892 462900 465910 
      470924 473930 479929 481924 483918 486907 489894 494883 
      500873 508863 516853 524840 533832 538827 540821 541806 
      540790 538779 537774 537769 534755 529734 528723 
 0.01 461220 459217 454216 450215 447212 442198 445190 444182 
      437177 434175 430175 421183 417185 415189 413196 415204 
      417209 422217 421221 421224 424228 429232 433235 437235 
      443236 448235 451234 456228 459222 461220 
 0.01 417115 419111 419107 419103 418101 417099 415097 412095 
      411095 409094 406094 405095 403096 402098 401102 400106 
      401110 402113 403116 404117 406118 408119 411119 413118 
      414118 417115 417115 
 0.01 384050 382035 380029 379023 376019 371018 364012 358002 
      354990 349979 347975 347968 345953 343944 343937 344931 
      346922 349908 351903 350898 351892 351886 350881 349877 
      343874 337875 332878 329882 328891 329899 329907 331921 
      328924 323926 316933 314937 312944 312950 312958 313965 
      316970 322977 323981 324989 325005 326020 326025 324030 
      320039 318045 317052 317055 319056 325056 335054 340053 
      344051 358049 364051 367054 369057 370062 370071 372079 
      376082 379082 381079 381069 383057 384050 
 0.01 328813 328808 326803 322798 319796 315796 308801 303806 
      300811 297816 295823 294837 296853 299859 303864 309868 
      315868 319862 320855 321847 321841 321833 324826 328813 
 0.01 303887 303884 301881 299885 298885 297888 296889 295892 
      295893 293896 293898 293900 294901 297901 299898 301894 
      302891 302888 303887 
 0.01 278830 276822 273816 269807 269799 267792 262786 259783 
      250778 246778 243782 242793 243806 244817 246829 249834 
      255835 264836 271835 277832 278830 
 0.25 484656 479649 477646 473646 467646 462646 454647 451649 
      448652 444659 441667 439676 439684 438692 438700 437705 
      435710 432717 434723 438726 443724 455712 466697 481684 
      485677 486669 486662 485658 484656 
 0.25 448808 448804 445802 443804 440804 437805 437806 435808 
      434812 435815 437817 438818 440819 443818 446816 447813 
      448811 448808 
 0.25 350027 351023 350020 349017 348013 347010 345007 344005 
      342007 342010 341014 342017 342021 343024 345027 346028 
      349028 350027 
 0.25 344996 345989 344983 342979 339973 337970 335965 332961 
      329962 328965 329971 330974 332981 334987 336991 338994 
      341998 344996 
 0.25 263804 262801 261800 258799 255800 255801 253802 252805 
      253808 255810 256811 259811 261809 263807 263806 263804 
 0.50 473671 471662 468660 464659 458660 454666 452670 451676 
      451680 452683 456685 461682 463679 466677 471674 473671  
 
$$