FXUS04 KWBC 022206 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 505 PM EST SUN MAR 02 2003 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID MAR 04/0000 UTC THRU MAR 06/0000 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY1... THE 18Z RUNS OF THE ETA AND GFS ARE IN PRETTY GOOD AGREEMENT WITH THEIR PREVIOUS RUNS SO NO SIGNIFICANT CHANGES WERE MADE TO THE PRELIM DAY 1 FCST. ...PACIFIC NW EWD TO THE UPPER MS VLY... TDAS MDLS ARE IN AGRMT THAT S/WV ENERGY DROPPING SWD ON THE ERN SIDE OF THE GLFAK UPR RDG/HI WILL SPLIT INTO TWO SEGMENTS..WITH A PTN OF THE ENERGY SLIDING SEWD INTO THE NRN PTNS OF THE NRN PLAINS/UPR MS VLY AND THE SCND PTN DIGGING S- SWWD OVR THE PAC NW TO NR THE NRN CA CST. THESE IMPULSES WILL HAVE LITTLE MSTR ON WHICH TO WRK..SO PCPN AMTS FM THE NWRN U.S. EWD TO THE UPR MS VLY SHUD REMAIN ON THE LGT SIDE. ETA AND GFS QPFS ARE IN VRY GOOD AGRMT OVR THE PAC NW AND NRN ROCKIES..WITH THE GFS SLIGHTLY HVIER OVR THE NRN PLAINS/UPR MS VLY. GIVEN THE LACK OF MSTR ACRS THE NRN PLAINS..HAVE OPTED TO SCALE BACK THE GFS QPF. MEANWHILE..THE HIER TERRAIN OF THE NRN INTER-MTN RGN..OR CASCADES AND NRN ROCKIES FVRD BY W-NWLY FLOW WILL SEE THE HVIEST PCPN TOTALS ( IN THE .25 TO .5 INCH RNG). ...NERN U.S... MDLS ARE IN GOOD AGRMT THAT NEG TILTED NRN STREAM TROF WILL SWING THE S/WV ENERGY OVR THE MID ATLC RGN RAPIDLY N-NEWD ALG THE NEW ENG CST AND INTO THE CANADIAN MARITIMES BY MON MRNG. AS A CONSEQUENCE..THE ASOCTD SFC LOW WILL ACCELERATE NWD AS WELL..TAKING THE STG WAA/MSTR ADVCTN WITH IT. HWVR..DURING THE 1ST 6HRS OF THE FCST PD THE VRY IMPRESSIVE LLJ (70-80 KTS) WILL LIFT SUFFICIENT MSTR NWD OVR THE ERN PTNS OF ME TO SUPPORT SOME LCL MDT PCPN AMTS HERE. THE BULK OF THE PCPN ACRS ME SHUD BE IN THE FORM OF SNOW WITH THE XCPTN OF DOWNEAST ME..WHERE TEMPS SHUD REMAIN WARM ENUF TO KEEP THE HVIEST PCPN AS RAIN. PLEASE REFER TO THE LATEST QPFHSD AND GRAPHICS 93S..94S FOR MORE DETAILS ON SNOWFALL POTNL FOR THIS RGN. MEANWHILE..THE ARCTIC BNDRY ASOCTD WITH THE NRN STREAM ENERGY WILL BE THE FOCUS FOR WIDESPREAD LGT SNOWFALL ACRS THE LOWER GTLKS AND THE CNTRL APLCNS RGNS. MDL QPFS ARE IN VRY GOOD AGRMT ACRS THIS RGN. ...TX EWD ALG THE GLF CST TO FL... MDLS CONTINUE TO SHOW A SERIES OF S/WVS MVG THRU THE SUB-TRPCL JET AND ACRS THE SRN TIER OF STATES THE AND GLF OF MEX. THE SUSTAINED SWLY MLVL FLOW WILL ALLOW A DEEP MSTR REGIME TO SPREAD E-NEWD OVR THE NRN GLF AND ALG THE IMMEDIATE GLF CST RGN TO NRN-CNTRL FL. THERE ARE SUBTLE DIFFS WITH THEIR TIMING OF THE S/WV ENERGY AND MSTR STREAKING E-NEWD..BUT IN GNL THEIR QPF OUTLNS ARE QUITE SIMILAR. DURING THE LAST 6 HRS OF THE PD..ETA AND GFS QPFS BEGIN TO DIVERGE SOME OVR SERN TX..AS SGFNT S/WV ENERGY ASOCTD WITH MLVL CNTR CURRENTLY DROPPING SWD THRU AZ MVS RAPIDLY EWD ALG U.S.-MEX BORDER AND INVOF TX/LA BY MON EVNG. GIVEN THE STRENGTH OF THE S/WV ENERGY..DECENT HT FALLS AND PWS APCHG 1 INCH..FEEL THE HVIER GFS SOLN IS MORE CORRECT. DAY 2... ...FL AND SE... THE HIGHEST QPFS THIS PD WILL BE IN NRN FL. ON DAY 1...A STRONG S/WV WILL EJECT OUT OF THE SW AND ACRS TX. THIS SYS WILL WEAKEN AS IT MOVS EWD. THE LEFTOVER ENERGY FROM THIS S/WV COUPLED WITH SEVERAL OTHER VORTS WILL BRING PRECIP TO THE SERN CONUS. MDLS FCST PWS AOA 1.50 INCHES AND GOOD MOISTURE CONV ALG STALLED FNT. THERE IS SOME DISAGREEMENT ON THE SRN EXTENT OF THE PRECIP SHIELD. THE ETA HAS A VERY TIGHT GRADIENT IN NRN FL. THE GFS AND CAN BRING LIGHTER AMTS FURTHER S. HAVE COMPROMISED IN THIS AREA...BRING SOME LIGHTER AMTS FURTHER S THAN THE ETA...BUT NOT TO THE EXTENT OF THE GFS. MAN PROGS WILL HAVE A SWATH OF QPF GRTR THAN 1.00 INCH OVER MOST OF NRN FL. ...GRTLKS/OH VLY... ETA IS DEEPER AND SLOWER THAN THE GFS WITH A SFC LOW OVER THE GRTLKS AND CDFNT EXTENDING SEWD FROM IT. THE CAN AND UKMET SUPPORT THE ETA POSN ON THE STRENGTH AND MOTION OF THIS LOW. HOWEVER...OVERALL EFFECT ON MDL QPF FCST IS MINIMAL. GFS ALSO LOWERS HGTS ACRS THE NRN TIER FASTER THAN THE ETA. THERE IS SOME LL CONV WITH THE FRONT AND DECENT VV. THE ETA IS SEEMINGLY HAVING SOME FEEDBACK PROBS BY THE END OF THE PD...AS IT DEVELOPS AN ANOMALOUS VV BULLSEYE IN THE OH VLY. NONE OF THE OTHER MDLS SUPPORT THIS FEATURE. ...WEST... ONSHORE FLOW WILL BRING GENLY LIGHT OROGRAPHIC PRECIP TO THE NW. A STRONG S/WV WILL MOV SWD AND OFF THE CA CST BY 60 HRS. THE ETA IS MUCH STRONGER AND SLOWER WITH THIS FEATURE THAN THE GFS. THE UKMET IS MORE SUPPORTIVE OF THE ETA SOLN...WHILE THE CAN SUPPORTS THE GFS. A COMPROMISE IS PROBABLY BEST HERE...UNTIL SOME MORE CONTINUITY DEVELOPS WITH THE HANDLING OF THE VORT. WILL BRING SOME LIGHT QPF INTO THE MTNS OF SRN CA...BUT KEEP THE BULK OFFSHORE. DAY 3... ...ERN CONUS... CDFNT WILL MOV EWD FROM THE GRTLKS TO THE ERN SEABOARD ON DAY 3. THERE ARE SOME DIFFS IN THE HANDLING OF THE LOW. THE GFS HAS A DEEPER MORE AMPLIFIED SOLN AT 72 HRS...AND IS FASTER AND FURTHER N BY 84 HRS. THE ETA ALSO HAS A SECONDARY LOW IN THE TN VLY...WHICH THE GFS DOES NOT HAVE. THE UKMET AND CAN ARE MORE SUPPORTIVE OF THE ETA SOLN WITH RESPECT TO THE LOW POSN. HOWEVER...THAT IS WHERE THE SIMILARITIES STOP. THE ETA CONTINUES TO HAVE THE FEEDBACK PROBS THAT DEVELOPED TWD THE END OF DAY 2. THE ETA HAS SEVERAL ANOMALOUS VV CENTERS THAT MOV ACRS THE OH AND TN VLYS AND INCREASE QPFS IN THIS AREA. NO OTHER MDLS SUPPORT THIS SCENARIO. AS A RESULT...HAVE TRENDED QPF TWD THE GFS SOLN. THERE IS NOT A LOT OF MOISTURE AND LL CONV IS LACKING. QPF AMTS ARE GENLY 0.25 INCHES OR LESS WITH SOME LOCALLY HIER AMDTS IN THE OH VLY AND NE. ...WRN CONUS.. LARGE UPR LOW WILL LINGER OFF THE SRN CA CST AND BRING SOME LIGHT QPF ASHORE. DIFFS REMAIN WITH THIS FEATURE AS WELL. THE ETA IS FURTHER W THAN THE GFS. WENT WITH A COMPROMISE HERE AS CONFIDENCE IS LOW WITH THE HANDLING OF VORTS IN THIS TIME PD. IN THE NW...ONSHORE FLOW AND MORE S/WV ENERGY WILL BRING THE POTENTIAL FOR OROGRAPHICALLY ENHANCED PRECIP TO THE NW. GOOD VVS ARE ALSO PRESENT. SOME LCL AMTS APPROACHING 0.75 INCHES ARE PSBL IN THE FAVORED AREAS OF WA AND ID...WITH LESSER AMTS ELSEWHERE. WOLF/JUNKER/NIERENBERG GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov 24HR QP VT 04/00Z 0.01 510652 505643 499636 494630 490628 482626 467625 453625 439626 428629 420632 413636 405642 392657 383672 374692 373696 374703 380710 391721 399721 405718 426710 434708 441711 442714 441717 439721 432730 428733 426736 422745 416754 413764 411773 409778 407781 399787 393791 383797 375803 367810 361817 356823 353833 354836 357835 362831 367830 369831 371837 372843 376856 381867 387875 392879 394876 393871 391858 389845 389836 389831 392827 400824 405822 406817 407808 410802 414800 417799 423799 427795 432788 436784 437779 440768 443758 447750 451743 456732 460725 466716 479708 488703 496697 499695 502695 505695 509696 511695 513692 513687 512666 510652 0.01 534200 535191 533185 533180 530175 519159 512151 504141 498131 498125 501120 505112 506106 506100 500101 496102 492102 488097 485090 482079 482070 485059 487050 489046 495040 511040 521035 524029 526025 527015 526010 526003 524992 523987 520978 516969 511959 508948 506938 503930 502922 501893 499875 496862 491854 485846 477840 469837 460833 450833 442833 435835 430836 425840 420845 415853 413861 411873 411886 412898 412911 412921 411932 413948 418956 423959 428961 436964 445976 452981 458985 460989 460996 460002 458007 453006 448003 442999 435997 430997 425000 424003 423015 423027 424042 423047 420052 413052 410054 404054 401060 398070 397074 397077 399078 404075 408077 414078 418076 420077 425077 429075 433082 434084 432086 427085 424085 423087 423093 421099 418103 417106 413108 411108 410105 409097 406096 406099 405104 403108 400110 394112 392113 392116 396120 403123 405125 409125 411124 414124 418126 419139 437123 439125 438129 435132 432142 430149 430156 431163 433165 435169 435173 432174 427172 422167 421165 421161 421153 419152 417153 415159 413163 411170 412181 415184 417188 418191 417194 415195 410195 407198 407201 410206 412208 413211 412212 408210 406208 398201 391197 382194 377195 379198 394211 400215 403218 404223 403226 401226 395226 391225 389223 387221 385222 383226 380230 381233 383238 385242 394248 405252 412256 424260 431260 439259 449260 453260 459258 467254 470253 477255 483255 488252 490245 489242 485238 482235 481230 479225 482224 491230 496234 502234 499222 500214 498209 492202 487198 482198 474202 467203 462199 462191 465178 465174 463170 459169 463169 466174 471175 476175 480177 483180 487182 490185 492191 494195 501198 506198 510197 515196 519200 530205 534200 0.01 445088 445084 444083 441083 439084 441087 443088 444089 445088 0.01 315802 314795 312790 308785 304782 299782 289787 284789 281788 276784 272780 269778 265779 263786 263793 263797 261802 260805 261810 266816 270823 272839 274844 273848 272855 268874 266890 266898 267906 269924 270931 272936 276942 278947 278952 276961 274967 272968 268969 257963 254962 251964 249968 248976 248981 251990 258002 262007 265013 267018 271019 273019 279022 301039 313046 321052 324060 330062 336060 341061 345058 345053 344048 341041 335037 332033 331028 329025 328022 326019 326013 326008 326002 327994 329987 331977 331968 330962 328958 326945 323936 320927 317918 315910 311889 309878 310869 313853 314837 315815 315806 315802 0.01 344099 342089 338080 335077 330077 326079 327085 330092 330099 328098 324095 321092 318090 315091 316101 318106 321108 325108 329105 332103 338104 342102 344099 0.25 495656 495651 493648 488641 482637 473635 464635 447635 439637 430643 425646 420652 415662 412671 406680 404684 404689 406692 411693 414692 431690 441689 449687 459683 467681 477678 482675 486670 492662 495656 0.25 490139 486134 481129 476125 473119 472114 474107 467102 465107 466113 468119 465126 462131 455143 454148 455153 458158 464161 469165 481160 479152 480146 490139 0.25 462242 463239 462236 458233 449232 449229 453226 459225 461222 460218 454218 445219 439221 437224 438228 439233 437236 432241 434244 438245 446245 453245 460244 462242 0.25 460181 459179 456178 454176 454176 453176 454177 454180 453182 450184 452187 456185 456185 459182 460181 0.25 453159 452157 450155 448154 447154 447154 447155 447158 449160 452161 453159 0.25 456110 458105 456103 453098 450096 447098 444101 438102 435104 433108 433112 435113 438113 441113 443116 446118 450117 454114 456110 0.25 305819 304813 301808 298807 296811 291819 289826 286835 285844 284855 282863 280872 279881 279891 282903 283908 287911 291913 295909 298901 300891 303874 305863 305853 306833 305819 0.25 310987 308980 306977 306971 306960 306954 307951 306942 304939 300940 299947 299954 300963 296969 292974 283981 276985 271989 271993 277998 283997 289996 296995 302995 307992 310987 0.50 484656 483651 480650 475648 464649 454651 449651 442654 439656 435662 425672 424675 423678 425680 430681 441683 451682 462678 473671 480666 483661 484656 0.50 444109 444106 441108 441108 441108 444110 444109 0.50 301835 298827 295827 291833 289839 288853 286866 284882 284890 286898 288901 291900 293896 298882 301869 302861 302854 301838 301835 1.00 455672 452670 450672 449676 451676 454674 455672 24HR QP VT 05/00Z 0.01 517742 513727 511722 507716 504708 500704 497697 494694 487682 483677 481674 476669 474665 465657 463655 459653 451650 447649 445651 437656 430663 427666 426672 427675 426681 424691 424699 422710 418734 417740 418744 425754 427758 429765 428769 425774 423778 420780 417789 414800 411809 403841 404844 403850 396856 392861 389867 387876 385886 384892 382896 378907 375916 370934 370940 372943 380944 387945 391945 393947 392964 394974 396981 396988 397995 396002 395008 396014 399020 402024 406030 412039 416049 415052 413052 408052 404052 400053 393057 387061 380063 370062 366064 367067 368072 371075 375083 382088 388090 394090 400090 403090 406087 410086 413082 419076 424075 427076 430080 432084 429086 419096 415099 413099 407099 403100 401102 394108 392118 393124 395128 398129 401128 407126 410130 415156 416167 419169 422167 424159 425134 425130 428127 432127 436128 439132 440137 444148 446155 450163 457167 466169 475172 483178 489187 493193 489200 473211 466217 464222 466227 476229 482230 489234 493235 497240 499242 502247 506254 508259 511264 518268 520265 522258 527245 529238 532230 536211 537207 539198 536181 533169 529156 526150 524147 516140 510133 506128 485102 478095 471089 463083 459078 456073 454068 453064 451044 450038 447034 441027 437001 436989 435983 436977 437968 442959 448941 453935 459927 467918 471916 477912 480910 482904 487890 496872 500861 501851 503839 502830 501814 503804 504801 506795 503782 517742 0.01 401227 404218 404213 402209 395200 383193 377192 371194 369196 365194 360190 355187 351184 345173 344169 342166 339164 331164 330165 329170 329175 331182 343200 346206 351211 354213 358216 363221 369223 374214 375213 376212 378211 379210 389228 393233 396234 401227 0.01 359758 357750 352745 348742 343741 335737 329733 323733 320735 313745 303748 293752 283754 279763 280769 278773 275782 274786 274792 276804 277814 275825 275837 273847 271854 270865 271877 270889 270898 272911 275916 278916 283913 286908 291900 295894 305876 316861 320851 322839 324830 327821 335800 338791 340787 344782 348781 351777 352769 357763 359758 0.25 524207 526203 526198 526194 525193 523190 520189 519191 5181