FXUS04 KWBC 241025 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 525 AM EST FRI JAN 24 2003 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID JAN 25/1200 UTC THRU JAN 27/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... THE 0600 UTC MODEL MASS FIELD FCSTS WERE VERY SIMILAR TO THEIR RESPECTIVE PREDECESSORS. SOME CHANGES WERE MADE TO THE FORECAST OVER THE PACIFIC NW TO REFLECT SOME MODEL QPF TRENDS...SEE TEXT BELOW... AND LATEST OBSERVATIONAL DATA. ...PACIFIC NW TO THE NRN ROCKIES... THE UPPER RIDGE OVER THE U.S. HAS TEMPORARILY FLATTENED WHICH IS ALLOWING SHRTWV ENERGY TO WORK INTO THE NWRN U.S. A RAPIDLY WKNG IMPULSE IS NOW MOVG INTO THE PACIFIC NW PER LATEST STLT IMAGERY AND WILL BRING LGT TO LCLY MDT PCPN OVR THE NRN INTERMTN REGION AND THE NRN ROCKIES. MODEL QPFS ARE SIMILAR HERE AND BASICALLY FOLLOWED THEIR GUIDANCE. MORE SGFNT QPF DIFFERENCES BTWN THE ETA AND GFS INVOLVE THE SECOND SHRTWV NOW NEAR 140W. THE ETA CONTINUES TO BE MORE AGGRESSIVE WITH THIS SHRTWV AND AS A RESULT DVLPS A MORE IMPRESSIVE SFC LOW WITH IT OFF THE PACIFIC NW COAST BY THIS EVNG. THE GFS/CANADIAN/ECMWF MAINTAIN A FLATTER SYSTEM AND FOR NOW WILL BE PREFERRED FOR THIS FCST. THE NET RESULT IS THAT THE ETA LIFTS THE STG LLVL ONSHORE COMPONENT...AND ITS ASOCTD WAA PCPN PATTERN...FARTHER NORTH THAN THE OTHER MODELS. THE 0600 UTC ETA AND GFS QPFS DID CONVERGE HERE FM THE 0000 UTC RUN WITH THE GFS MOVG MORE TOWARDS THE FARTHER NORTH ETA QPF RATHER THAN VICE VERSA. GIVEN THE GFS QPF TREND OPTED TO COMPROMISE BTWN THE TWO QPF SOLUTIONS DESPITE PREFERRING THE GFS MASS FIELD FCST. WITH LATEST STLT IMAGERY INDCTG PWS APCHG 1.50 INCHES ASOCTD WITH THIS SYSTEM...MDT TO LCLY HVY PCPN TOTALS ARE EXPECTED. OTHERWISE...THE WEATHER PATTERN WILL REMAIN VERY DRY ACROSS THE NATION. A VERY WEAK WAA PCPN PATTERN WILL SPREAD ACROSS THE NRN PLAINS WITH THE AFOREMENTIONED FAST SHRTWV NOW APCHG THE PACIFIC NW. SHWRS ARE POSSIBLE ALONG THE LWR TX COAST WHERE STG LLVL BAROCLINICITY ASOCTD WITH A COASTAL FRONT WILL BE IN PLACE. DAY 2... AGAIN MOST OF THE PCPN THIS PERIOD WILL BE CONFINED TO THE PACIFIC NORTHWEST AND NRN ROCKIES. WENT WITH A MODEL BLEND ALONG THE COAST. INITIAL UPSLOPE CONDITIONS IN THE NRN ROCKIES WILL BE REPLACED BY THE PACIFIC MOISTURE ROLLING INLAND. SNOW SHOULD BE CONFINED TO THE HIGHER ELEVS MAINLY EAST OF THE CONTINENTAL DIVIDE DUE TO THE STRENGTH OF WARM ADVECTION WITH THIS SYSTEM. OTHERWISE...ANOTHER TROF DIGS DOWN INTO THE GREAT LAKES WITH LAKE EFFECT CONTINUING. SRN STREAM VORT MOVING INTO THE SRN HIGH PLAINS WILL ENHANCE PCPN ALONG THE TX GULF COAST. DAY 3... WET CONDITIONS CONTINUE ALONG THE PACIFIC NORTHWEST COAST AND NRN ROCKIES AS FRONTAL BNDRY PUSHES INLAND. AGAIN EXPECT SNOWFALL TO BE CONFINED TO HIGHER ELEVS WITH PERSISTENT RELATIVELY MILD PACIFIC INFLOW. IN THE EAST...AMPLIFYING UPPER TROF KEEPS LAKE EFFECT SNOW GOING BUT WITH LITTLE IN THE WAY OF SIGNIFICANT ACCUMULATIONS. LIGHT PCPN ALSO SPREADS NORTH AND EAST WITH THE PASSAGE OF ANOTHER ARCTIC BNDRY THROUGH NEW ENGLAND AND THE MID-ATLANTIC. ALONG THE GULF COAST...REMNANTS OF OLD FRONT SERVE AS FOCUS FOR .25 INCH QPF OVER SRN LA. KORTY/MAUSSER GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov 24HR QP VT 25/12Z 0.01 541202 542181 540172 537163 535153 535145 533132 532123 531116 530113 528103 523085 520077 519070 515054 511039 505021 501016 497012 491010 489002 479967 477964 474963 470967 466979 463995 463014 464021 468028 473041 476051 479058 482066 485072 493083 499095 505106 512120 514124 514128 511134 507136 504136 496134 491129 485125 481122 475120 472115 475107 475101 473098 470093 427091 427100 424104 418106 415104 414101 412095 410090 406089 403097 400097 399093 401086 404083 412080 417076 417071 415069 418064 414058 405053 399053 394056 389060 383062 379065 375064 369064 371068 375073 375077 375083 378085 381084 383082 387082 390086 392090 391094 391103 391107 390111 390116 392117 396118 400120 399126 399129 401129 405129 408132 410135 409140 400148 399153 399158 402163 407167 409174 411188 408194 402196 396195 389192 376190 370190 370193 373200 377206 385215 387216 379215 363213 361213 360217 362221 368230 376239 384246 391251 397253 402256 410259 423261 438264 443265 450267 462274 468276 474277 478277 483276 494277 512291 525256 524253 523251 522247 521245 520242 519239 518235 517234 516229 515228 513224 513223 514218 514218 517219 518220 520221 522225 524227 525227 527231 530233 532234 0.01 488884 487872 485860 483849 479839 473837 466842 464841 463838 463828 462818 460809 457803 455800 451799 440798 432800 429803 426807 428811 430813 436817 441821 445827 447832 446840 440845 432848 425849 419849 411851 406856 405862 407867 412872 417875 423876 431875 439872 454864 457863 459868 460880 464902 466906 469907 473905 477906 482905 484903 486899 488889 488884 0.01 440761 439760 438757 435756 433756 431754 429757 428759 427762 427764 428768 429771 430775 432778 432778 433778 434774 435772 436770 438767 440765 440762 440761 0.01 478946 476939 474934 470929 464926 458925 449924 445926 442929 447936 451939 457945 462950 469952 473951 478946 0.01 417811 417809 415808 413808 411810 410811 409815 409817 409819 410821 412822 414822 414821 416817 416816 417812 417811 0.01 411790 406785 401787 396790 388795 385798 384802 379808 379811 381814 384816 387815 395810 400804 405801 409798 411794 411790 0.01 448076 447074 446072 444070 443072 444074 446076 447078 448076 0.01 415932 415926 414921 411914 407907 404904 401902 397902 395905 395911 395920 395929 398936 402943 404947 408947 413941 415935 415932 0.01 274802 274799 272797 269797 264797 260796 255797 252798 250801 251804 254805 259803 265803 268803 271804 274802 0.01 296979 292970 292967 290965 287964 279967 271965 265966 260967 257970 254973 256977 259980 265984 271990 276991 282991 287989 292987 296979 0.25 532210 532198 530189 523178 519172 515166 509161 505159 499159 494162 488163 484160 478158 471155 467154 463155 458152 444147 441147 439150 438154 439162 442167 443170 443175 440181 438186 438193 442207 442211 439213 434213 430210 427207 424210 424215 423219 419225 418225 417222 417218 415215 408213 404211 402212 401216 403223 402226 397228 392232 390235 392239 396243 402247 413251 425253 437252 448250 454250 461254 464257 468259 472260 482254 485250 490249 496248 500247 503251 508254 509254 508243 506236 502223 499215 496208 494202 487197 487190 490189 494192 501192 505193 509195 513199 518205 522210 526213 529213 532210 0.25 491239 492234 491233 489229 489228 486225 483225 480226 481231 482232 484236 484238 487240 490242 491239 0.25 481173 480173 478168 478168 475165 472165 471167 470171 470175 471176 474178 477178 479177 480174 481173 0.50 525198 525197 523192 523192 520188 518186 518185 515185 514185 515186 516190 517192 519196 519196 522199 525198 525198 0.50 486214 485208 481204 475201 470201 460206 452212 433220 430222 428229 424232 417230 414229 413226 413219 410218 407225 407229 404231 400232 398233 397237 400241 407244 413246 422249 426250 432249 441244 445244 452244 462246 469248 474246 478242 478238 476236 474233 473226 476221 481219 484217 486214 1.00 465221 463218 460218 459220 460223 463223 465221 1.00 423242 425238 422237 419236 416235 413234 411234 410236 409237 410238 413239 415240 418241 421242 423242 24HR QP VT 26/12Z 0.01 539209 537201 534195 533188 533181 532170 531162 530157 527146 521130 513107 506088 497068 488051 482040 478034 475030 475025 478020 482011 483000 483986 481970 478946 477928 478913 480901 484889 487881 488873 488854 493838 496828 500789 497756 502721 500688 494665 485657 470662 455674 447683 439703 437708 439715 442720 444727 442731 439734 436738 430744 427751 425756 426763 427769 426773 423779 420783 414788 412791 411799 414812 412829 409852 408864 411882 413892 418900 422903 429904 432907 434913 435919 437922 444928 445934 443938 441947 440950 441957 441964 443969 445976 444979 442980 433966 426956 422951 417946 405940 398938 392940 391944 393958 396972 398984 400996 403006 406015 410023 419036 426045 433056 434067 431078 424089 413097 408098 401102 396106 394109 394114 396122 402128 407132 413133 419138 419143 410144 404146 400154 403159 408164 416169 421171 425171 427176 424181 425189 426192 424197 418200 415206 411209 402216 394226 392230 391235 394242 399250 405255 413259 422260 428260 431261 441264 448267 454271 464276 473281 478285 487290 496296 506301 0.01 421064 418058 412054 407052 403051 398052 392056 388061 383068 384076 387080 390082 395083 399083 407083 414080 419076 421066 421064 0.01 326938 322930 318928 310929 301934 292939 274951 267956 259961 257964 255970 255974 256979 260987 273986 282988 288990 293993 299995 305995 308991 308985 306979 306976 310973 314970 318966 322956 324948 326938 0.01 283795 281790 277788 271787 260789 252795 247801 241808 240816 242818 247819 255813 258811 264810 271810 275810 280806 282804 283798 283795 0.25 524261 523246 523228 519191 515177 511165 505153 500136 496122 492109 490104 487096 479083 474072 468063 465058 460054 457054 455055 453060 453064 453071 454076 456081 457086 457091 453097 449101 447104 446107 449112 457118 459124 457132 456139 457147 459154 464161 464165 464166 460167 454166 450169 443181 440188 439193 440197 444207 439211 435213 429217 426223 424227 421229 414234 410240 411243 413246 423252 431254 437255 448256 459258 465260 472263 485272 498283 503287 509289 512289 0.25 469847 468839 466837 463837 459843 458848 458852 460855 463858 465866 468874 469882 472886 473882 472877 471869 470860 469851 469847 0.25 464202 467201 470198 469195 465193 461194 457198 458197 457198 460201 464202 0.25 285965 284964 282963 279963 276964 274966 272967 271970 271971 271971 274972 277971 280971 282970 284969 285967 285965 0.50 518273 520269 520263 518254 515236 506202 506192 503186 499184 497187 497195 493199 487199 480199 474202 465209 452214 440218 435220 429228 428232 424238 418240 420246 427248 434249 449251 453250 461252 469254 478258 490266 502278 507281 511280 516276 518273 0.50 491144 491138 489130 487122 484114 482106 478098 473091 472089 468087 466091 465098 467106 473112 478120 481128 483138 488144 491144 1.00 509255 509249 507240 505233 501224 498220 493216 488211 482209 479209 475210 473213 473218 475224 471226 465229 461230 455234 455238 456241 460242 466244 474247 480249 488254 494258 498258 501256 509255 1.50 480239 479236 477234 476233 475233 473237 475240 478241 480239 24HR QP VT 27/12Z 0.01 482728 493694 493662 485631 476621 462623 449632 436649 424671 411704 398738 377775 372784 367791 363798 359807 356817 351836 349849 346866 348879 351886 356892 362902 366920 372932 378941 385943 393941 398933 402922 404908 406900 407889 410880 417878 428878 442874 448872 452871 455871 459873 459878 459893 460903 463907 467909 473907 476906 478902 481897 485888 488875 489870 488862 484851 477843 471837 465831 460825 458820 455815 451811 448807 446800 444786 447775 450767 454762 458758 473742 482728 0.01 548169 544158 541150 534137 524130 521123 528115 532105 530084 520042 508998 497978 472969 458970 437973 426977 423979 422982 422986 427994 433000 438008 441012 441019 439029 437033 438038 440051 444064 441069 438072 438077 443078 451080 456083 456085 446084 436084 431084 427082 424078 422072 423068 421065 420062 416057 414055 405052 401051 397053 391059 387066 384072 387076 390080 395082 403083 409086 412089 414094 411098 405103 402113 403117 405121 410129 412133 413138 412142 410148 408151 406155 405160 411166 412170 411174 410177 404200 390213 386220 383225 382229 381237 383241 387245 394250 404254 409257 411260 418262 423262 438258 448258 457260 467265 473270 489286 507300 0.01 333895 331888 326882 321878 318873 314863 312857 307839 303832 298826 294823 288822 284823 282826 281833 281846 281862 281877 281889 281905 282928 278949 278955 279963 285966 294966 302965 314959 320954 325949 331937 332929 333922 333913 333906 333895 0.01 278797 276791 272791 264792 256797 251803 245811 243815 243818 243821 245823 248825 252825 257823 264818 271812 276805 278801 278797 0.25 537206 538198 537192 535181 530172 525165 518160 512156 503152 497148 485134 480129 473124 466119 464117 462111 458102 453097 445095 439097 430099 424102 419109 419115 422118 437124 443128 444134 442137 436141 431148 430154 434162 439168 442174 445178 449181 453183 458184 465183 474182 478184 484185 491183 500186 505190 518202 524207 528209 533210 537206 0.25 524261 522250 520244 513228 505216 500210 495204 489201 484200 477202 471205 459210 449214 443215 435214 428213 420212 408214 404217 400223 395229 394234 395237 408245 413250 418253 423253 429252 435250 443249 455250 464253 471258 482267 503288 511292 0.25 301940 308938 313932 314924 310916 308911 306905 307898 307893 305886 301882 296881 292884 290890 289894 289902 289907 291912 294919 294927 294932 295938 298941 301940 0.50 521270 520259 517249 512234 508226 504220 499214 494209 486205 484205 477207 470210 460215 448220 440225 429230 422231 416226