FXUS04 KWBC 221023 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 523 AM EST SAT FEB 22 2003 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID FEB 23/1200 UTC THRU FEB 25/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR THE 06Z MDL RUNS WERE IN VRY GOOD AGREEMENT MASS FIELD-WISE TO THE 00Z RUNS..AND QPFS WERE IN REASONABLY GOOD AGREEMENT. BECAUSE OF THIS..MADE ONLY MINOR CHGS TO THE PRELIM DAY 1 QPF..BASED MAINLY ON LATEST RADAR/SATL IMAGERY. DAY 1... ...ERN 1/3 OF THE COUNTRY... LATEST MDL RUNS ARE IN EXCELLENT AGREEMENT WITH THE TRACK AND SPEED OF THE SYS LIFTING NEWD THRU THE ERN STATES THIS PD..AND FOR A CHG..ARE ACTUALLY IN REASONABLY GOOD AGREEMENT QPF-WISE. ALL OF THEM TAKE A RATHER STG SFC LOW INTO SERN OH BY SAT EVE..AND THEN INTO CNTRL NY STATE BY SUN MRNG. WITH A TRACK THIS FAR W..SIGNIFICANT SNOWS WON'T BE A PROB THIS TIME ARND..XCP FOR PTNS OF ME AND MAYBE PARTS OF THE SERN GTLKS REGION. WHAT COULD BE A PROB IS THE RNFL..WHICH WL BE MDT TO LCLY HVY IN LOCATIONS..AND WHICH WHEN COMBINED WITH SOME SNOW MELT..COULD CAUSE SOME FLOODING PROBS. HOWEVER..DON'T THINK THE REAL WRM..HUMID AIR WL MAKE IT FAR ENUF N INTO AREAS THAT STILL HAVE A DEEP SNOW PACK..SO ANY FLOODING PROBS SHLD HOPEFULLY BE ISOLD IN NATURE AND LIKELY THE RESULT OF POOR DRAINAGE. IN ANY CASE..WIDESPREAD MDT TO HVY RAINS WL BE THE RULE FM THE OH VLY ENEWD THRU THE MID ATLC STATES AND INTO NEW ENG..SUPPORTED BY A STG LOW LVL WAA REGIME UP THE E CST AND STG FORCING IN THE COMMA HEAD UP THRU THE OH VLY..ALG AND JUST TO THE LEFT OF THE TRACK OF THE MID LVL SYS. THE ETA HAD A LTL MORE QPF IN THE COMMA HEAD REGION..AND LEANED TWDS THIS SOLN..BUT ALL IN ALL..MDL QPFS SEEMED QUITE REASONABLE. ACRS THE ERN GULF CST STATES..AND IN PARTICULAR FL..THERE SHLD BE ENUF LOW LVL CNVGNC VCNTY OF THE FNT AND HI MSTR IN PLACE TO SUPPORT A BAND OF AT LEAST MDT RAINS WITH THE CDFNTL PASSAGE..IN SPITE OF A LACK OF HGT FALLS ALOFT. ...NRN GT BASIN/NRN ROCKIES SEWD INTO THE CNTRL PLAINS... PRETTY IMPRESSIVE S/WV NOW ENTERING THE PAC NW WL DROP SEWD THIS PD..REACHING THE CNTRL/SRN PLAINS BY SUN MRNG. STG MID LVL DYNAMICS SHLD TRIGGER LGT TO MDT SNOWS FM THE MTNS OF CNTRL ID SEWD INTO CO..ESP IN THE HIER ELEVS. SOME LCLY HVY SNOWS ARE ALSO PSBL IN THE LWR ELEVS FM SWRN NE SEWD INTO KS..PRODUCED BY SAME MID LVL FORCING AND ENHANCED LOW LVL CNVGNC ASSOCTD WITH DEEPENING SFC LOW AND IN SPITE OF WHAT WL BE RATHER LIMITED MSTR. LEANED A BIT MORE TWDS THE HVIER GFS QPF IN THE PLAINS. PLS SEE QPFHSD AND GRAPHICS 93S AND 94S FOR DETAILS ON THE SNOWFALL POTNL. DAY 2... ETA AND GFS QPF VERY SIMILAR OVER MOST OF THE LOWER 48 THIS PERIOD. WET SYSTEM MOVES OUT OF NEW ENGLAND INTO THE CANADIAN MARITIMES. THERE COULD BE A FAIR AMT OF ICING OVER EXTREME NRN NY AND NRN NEW ENGLAND EARLY ON BUT THIS SHOULD CHANGE OVER TO ALL SNOW AS COLDER AIR WRAPS IN ALOFT BEHIND THE MAIN CIRCULATION. IN ANY EVENT PCPN AMTS GREATER THAN 1 INCH WILL BE CONFINED TO NORTH OF THE BORDER. SHORTWAVE INITIALLY OVER CNTRL OK WILL MOVE UP THROUGH THE OH VALLEY AND WILL SPREAD A SWATH OF LOCALLY HEAVY SNOWFALL FROM SERN KS ACROSS S-CNTRL MO AND EXTREME SRN IL. ALSO EXPECT A SMALL AREA OF ICING TO THE SOUTH OF THE MAIN SNOW AREA. LIGHTER SNOWFALL WILL PERSIST OVER THE ROCKIES AND FRONT RANGE IN THE UPSLOPE AREA TO THE SOUTH OF THE ANTICYCLONE SETTLING OVER THE HIGH PLAINS. MODELS FAIRLY CLOSE WITH THE UPPER LOW LURKING JUST OFF THE NRN CA COAST. MANUAL QPF COMPROMISED BETWEEN THE ETA AND GFS. DAY 3... CA RECEIVES THE BULK OF THE PCPN THIS PERIOD WITH THE APPROACH OF A POTENT CLOSED LOW FROM THE ERN PACIFIC. MANUAL QPF LEADED MORE TOWARD THE ETA DUE TO ITS GENERALLY SUPERIOR TOPOGRAPHY WITH THE DEPICTION OF THE COASTAL RANGES IN CNTRL AND SRN CA. HOWEVER...HAVE STILL INCREASED COVERAGE OF THE .50 INCH ISOHYET FROM THE ETA DUE TO RELATIVELY SLOW FORWARD SPEED OF THE MAIN UPPER SYSTEM. BROAD AREA OF UPPER DIFFLUENCE SPREADS SIGNIFICANT PCPN INTO THE GREAT BASIN AND CNTRL ROCKIES. RELATIVELY WEAK AND FAST MOVING UPPER TROF MOVES THROUGH THE GREAT LAKES WHICH HELPS TO LIFT SHORTWAVE ENERGY FROM THE UPPER OH VALLEY THROUGH NEW ENGLAND. EXPECT MAINLY LIGHT SNOWFALL FOR MUCH OF THE NORTHEAST. TERRY/MAUSSER GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov 24HR QP VT 23/12Z 0.01 432604 429609 423615 420622 414628 401647 396654 393659 385671 372689 334727 306748 271777 253791 243802 238812 234825 237837 242849 251859 261865 271869 286873 302872 306870 314869 320869 325870 328873 330880 329889 329891 331905 332919 335928 340942 342955 344971 345986 347997 350005 357016 365025 374031 380037 382039 383042 382047 379049 372053 370055 367059 366063 369068 373077 375083 379086 387094 389098 389105 383112 380117 381121 385127 390130 397131 410132 412133 413137 410143 407149 404156 404159 406160 414162 420164 424168 428169 432168 434167 438167 441169 442172 442177 437189 442194 446195 450195 454193 461186 465183 469180 472178 478178 483180 485185 485192 481196 469201 466204 461205 451209 440213 435216 434222 435225 442227 447227 453226 458227 463227 467226 476225 487224 489225 501226 507233 509240 515245 522239 529212 523137 513095 504072 500060 496043 494031 492004 492000 491992 487985 481982 476986 471991 468996 465000 457006 450006 445005 438003 430003 421998 417994 413989 403975 401970 397966 390960 376947 372943 366940 367937 371935 374932 385922 395908 407888 412883 416880 429876 442873 452874 456875 462880 466883 469883 473878 476871 478861 479850 482823 502699 502684 500668 494648 490637 484624 478615 474608 471605 467600 464598 453591 443592 0.25 478656 475648 471640 465628 457616 454613 449609 442610 436612 433616 425626 419635 408654 396673 384690 371705 357721 347729 339736 322748 308759 275785 268792 262798 253810 248818 246825 247829 251831 260833 266837 271843 284850 291856 294858 299858 319857 333857 338859 341861 347870 349878 348889 347902 344911 343916 345921 347924 352925 362922 371916 378908 384901 391893 398885 410873 422857 436840 442831 448821 467785 473773 477764 481750 484738 485728 485716 485703 484691 483679 481669 478656 0.25 474159 474140 474136 472128 467109 470112 470106 464102 458091 453084 447076 446082 446085 445088 441089 436092 432100 429105 428108 429111 432113 438115 447119 453126 450139 447154 448159 449161 452165 458160 467163 472162 474159 0.25 435064 435053 435047 434041 431035 426029 418018 411007 404996 397986 392980 388976 378970 366964 363965 362968 364976 375001 379007 384013 391021 406042 412048 413050 412055 409060 404061 399062 396064 394066 393071 396077 400078 403076 407071 412066 416065 420066 427066 435064 0.25 415114 414114 412113 409113 408114 409114 411115 414115 415114 0.50 456631 453624 449620 446617 441617 438619 433623 426634 416652 408669 402681 397689 391698 384707 377715 371720 358729 337745 306770 283789 262807 254819 259824 265822 271819 279819 285824 291830 296835 294844 294848 297851 300852 305852 309852 315851 323851 333851 350853 357855 362862 365870 363883 358894 351907 350912 348917 350919 354919 362914 370909 374905 377901 382893 398879 404873 409866 421850 433833 440822 445812 453797 458786 463774 469752 471746 470739 470725 469713 467700 465688 463680 463674 463663 461650 456631 0.50 385743 383740 379741 372746 365755 356767 348776 341781 336785 323793 321796 324798 328799 339798 341801 337807 327815 315824 310828 309831 312834 323833 331831 337829 345825 350822 360813 364807 367800 373789 375784 375774 375768 377762 382751 385743 0.50 390994 389993 389991 387987 386985 383984 383984 380983 379985 379988 380990 382992 384993 386995 388995 389995 390994 1.00 437682 441660 443653 443644 442635 437634 430641 425651 420665 417677 412689 408698 404707 402717 404732 403741 397752 394760 392770 392777 389789 379802 371813 361826 354831 350835 349840 355842 363841 369836 375830 385818 390810 394802 397796 401790 406784 413776 420773 425774 427778 429780 428785 427789 424796 419802 412813 402834 398848 394866 395871 401865 408855 418836 432807 437797 439787 439782 438779 436777 435768 433748 432736 433727 437707 437699 437689 437682 1.00 345764 352757 357752 358748 353747 350748 339760 335764 335767 337767 345764 1.50 411733 407748 405754 405756 405759 405761 407761 409759 413749 421723 423714 419711 416714 414720 411733 24HR QP VT 24/12Z 0.01 532705 532717 532725 530735 528745 522758 517767 515771 510776 505782 493793 485798 477802 465807 456811 450812 435817 427821 423825 422829 421839 418849 416857 414867 413874 413883 411893 410899 407906 407910 408915 411921 416928 421934 424940 431956 437977 442002 443007 447009 458048 464095 469142 464170 462183 453198 447200 443189 439178 435164 431149 431135 424128 415122 410118 405114 401106 398102 392095 387091 375088 370082 370073 366069 365064 366060 375058 378054 376049 369037 361027 357020 356013 356007 356998 352981 351971 351961 351955 350944 350930 349921 347911 344910 343911 335921 330927 325931 321932 319930 317928 316923 317917 320909 326898 333885 333878 337870 348856 356845 366834 370830 371828 368827 361829 357826 358819 362814 371803 377796 384792 392784 396776 399769 404765 404759 402755 400746 401740 405732 410719 413704 413695 413687 412676 414667 416657 419647 425633 435619 438613 444605 451598 457591 466587 476587 483590 490597 0.01 450238 450233 448230 439227 440214 441210 438204 434201 429190 421177 417172 414167 410161 409156 407152 404148 398145 393142 387144 385145 384150 386156 388164 389175 389179 387183 383184 380184 372182 367181 366182 364185 364189 366197 370200 377204 382207 386212 387219 387231 387236 389243 395248 405249 417249 429248 436247 442244 450238 0.01 272797 272793 271790 268788 262788 258790 248796 242803 239810 237817 238826 239829 242831 250827 256820 262814 267808 271800 272797 0.25 510641 505628 498616 492607 485601 479599 471600 464603 456610 451617 445628 440646 439656 441662 444665 450672 453679 453690 451702 446710 441717 438721 437726 438738 438748 437758 438766 442768 446769 453769 461767 480758 488756 495754 499751 503747 509737 514729 517719 519708 520694 519683 518676 516668 512651 510641 0.25 412799 411791 408787 403785 400787 394794 393801 394812 392822 386837 376852 370866 366875 364884 364904 361925 360933 361942 362953 365964 369970 376974 383977 389975 391972 392966 392957 393911 393889 394880 397871 400864 402858 402852 403834 404824 407814 412799 0.25 410068 411064 412060 410057 410056 407056 404055 402057 401059 400061 400064 400068 401069 404070 407070 410069 410068 0.25 246808 244813 245815 246816 248816 251813 254809 256804 255801 253801 249804 246808 0.50 502633 499625 495619 488609 483606 476606 467611 462617 459624 457635 457643 460652 462665 463673 464681 463694 461709 459720 459726 463735 467737 471738 475738 482736 488732 493727 502716 508704 510698 511689 511683 511673 509658 505641 502633 0.50 390848 390851 391853 394852 396847 396842 392840 391842 391843 390847 390848 0.50 384950 384942 385933 384919 382903 381894 379891 377890 375891 375895 375903 373910 371917 367929 365936 366944 368957 373964 378966 381964 383960 383955 384950 1.00 497643 496638 493632 490628 483627 480629 478634 477641 477647 477664 477680 475694 475703 477707 481707 484702 487699 491691 494683 497670 498653 497643 24HR QP VT 25/12Z 0.01 461882 473883 482870 478846 472834 475801 477784 482763 491747 500720 509690 512658 503639 477630 454640 433654 419673 406689 402702 404725 400753 389780 385785 377799 372811 370818 370822 373823 377821 384815 390812 396811 400818 402825 406851 410865 413869 417873 423876 428877 435879 443879 450879 457880 461882 0.01 433225 434216 435209 434202 432185 428168 424147 422134 426123 428114 428102 429089 428077 427068 426060 424055 421047 415041 404032 400027 396020 392011 389002 385982 382973 376970 372968 367969 361973 350985 341997 338999 336003 338013 343028 349046 352053 355062 357070 361076 368088 377101 375108 371114 364116 360116 356116 351120 347128 346133 347137 348141 349147 349155 343157 336156 331156 328158 322161 319168 318175 320184 323192 326199 328205 332211 340222 352233 366243 372246 378251 386253 392254 410254 418252 424245 430233 433225 0.01 283802 282794 280791 277788 273787 267789 256793 246800 244803 242809 241819 243822 247826 257828 263829 269825 275818 281808 283802 0.25 421229 424220 425215 424210 422204 419200 416195 412188 410174 407168 405162 404154 405145 407137 414110 415079 412060 402054 391055 385057 374058 368061 367066 369073 372079 375083 379086 384087 389090 391093 392098 389109 381116 375125 373132 372140 369147 366150 362152 360157 363170 359174 354175 348172 344167 341165 338164 330165 327168 327172 328179 330185 335197 339207 346214 355222 364230 375237 384242 391244 397244 408241 416236 421229 0.25 373179 377179 380177 381173 378170 374170 371170 369172 370176 373179 0.50 407225 409222 409218 405213 397209 389203 384196 381192 377188 370183 366181 362181 357184 354184 348179 341171 336171 333173 333176 334182 337190 341198 346206 352214 359220 368226 375231 384236 389237 393236 401231 407225 0.50 409118 411114 411110 4