FXUS04 KWBC 281004 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 503 AM EST TUE JAN 28 2003 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID JAN 29/1200 UTC THRU JAN 31/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... THERE WAS LITTLE DIFFERENCE BTWN THE 0000 UTC AND 0600 UTC MODEL RUNS. THE ETA AND GFS MASS FIELD FCSTS ARE IN GOOD AGREEMENT ACROSS THE NATION THRU DAY1 WITH ANY DIFFERENCES BEING IN THE NOISE LEVEL. MINOR CHANGES..MOSTLY DUE TO CURRENT OBSERVATIONAL DATA...WERE MADE FM THE PRELIM TO THE FINAL DAY1. ......MIDWEST ACROSS THE NRN PORTION OF THE OH VLY... MOISTURE AVBLTY WILL BE ON THE INCREASE HERE AS A STG LLVL SLY WIND COMPONENT ADVECTS HIER MSTR INTO AN E/W ORIENTED BAROCLINIC ZONE. A VERY WEAK WAA IS EXPECTED OVR THE OH VLY EARLY IN THE PD. THE BULK OF THE PCPN DEPICTED HOWEVER WILL BE TRIGGERED BY THE DYNAMIC LIFT ASOCTD WITH THE SHRTWV FCST TO BE PRESSING EWD ACROSS THE CNTRL U.S. BY THIS EVNG. IN GNRL LGT PCPN AMTS ARE EXPECTED WITH THIS SYSTEM. THE 0000 UTC GFS WAS HEAVIER THAN THE ETA WITH AMTS OVER THE MIDWEST THRU THE FIRST HALF OF THE PD AND BELIEVED IT WAS OVERDONE GIVEN THE FCSTS OF AVBL PW AND RECENT WET BIAS ON ITS PART. MORE TROUBLING WAS THAT THE 0000 UTC GFS PCPN AXIS IN GNRL WAS SLIGHTLY NORTH OF THE ETAS AND THE ETA HAD TRENDED A BIT NWD FM ITS PREVIOUS RUN. FORTUNATELY...THE 0600 MODEL RUNS WHETHER RIGHT OR WRONG BASICALLY CONVERGED ON BOTH AMTS AND THE AXIS OF PCPN. A COMPROMISE BTWN THE MINOR REMAINING DIFFERENCES IS PROBABLY THE BEST BET. ...LWR MS/TN/AND SRN OH VLY... DIFFICULTY HERE IS TRYING TO GAUGE WHEN AND WHERE ENUF MSTR WILL BE AVBL TO SATURATE THE ENVIRONMENT AHEAD OF THE AFOREMENTIONED SHRTWV ADVANCING EWD FM THE CNTRL U.S. BY THIS EVNG. BOTH THE ETA AND GFS HAVE SOME DIFFERENCES HERE BUT BOTH BASICALLY AGREE THAT SHWRS WILL DVLP ACROSS THIS REGION AS HGT FALLS GRADUALLY SQUEEZE MSTR OUT OF THE ATMOSPHERE. ATTEMPTED A COMPROMISE BTWN THE TWO QPF SOLUTIONS GIVEN THE LACK OF SGFNT MODEL DIFFERENCES. ...NRN PLAINS... OVRRNG OF ANOTHER ARCTIC FRONT DROPPING SWD ACROSS THIS REGION WILL TRIGGER VERY LGT PCPN TOTALS. THE ETA AND GFS ARE IN GOOD AGREEMENT ON DETAILS HERE. DAY 2... SE... SLOW MOVING COLD FRONT DRAPED ACRS THE REGION WILL ACT AS A FOCUS FOR MSTR FEEDING UP FROM THE GULF OF MEXICO AS SRN STREAM S/WV ENERGY SHEARS EWD ACRS THE REGION. OVERALL.. THE ETA AND GFS ARE IN RELATIVELY GOOD AGREEMENT HERE WITH THE PCPN AND BASICALLY JUST WENT WITH COMPROMISE SOLN. PAC NW... GOOD AGREEMENT HERE ALSO BETWEEN THE ETA AND THE GFS AS THEY BRING A FAIRLY POTENT S/WV OUT OF THE ERN PACIFIC INTO THE NW. SUPPORTED BY GOOD ONSHORE FLOW INTO THE REGION... THIS SYSTEM WILL PRODUCE MDT TO HVY RNFL ALONG THE COASTAL RANGES OF WA AND OR AND INTO NRN CA. THE ETA IS WETTER HERE THAN THE GFS AND GIVEN THE RATHER IMPRESSIVE 20 TO 30 KT LOW LEVEL JET FEEDING INTO THE FAVORED UPSLOPE AREAS WITH PW'S OVER AN INCH... CAN SEE NO REASON TO NOT GO WITH THE HEAVIER SOLN. DAY3.... LITTLE IN THE WAY OF SGFNT CHANGE FROM DAY2 INTO DAY3 AS PERSISTENT ONSHORE FLOW INTO THE PACIFIC NW CONTINUES TO BRING PLENTY OF MSTR INTO THE REGION. ETA AND GFS ARE ACTUALLY IN BETTER AGREEMENT ON DAY3 THAN THEY WERE ON DAY2 WITH BOTH SHOWING BETWEEN 40 AND 50 KTS OF LOW LEVEL JET BRINGING PW'S IN EXCESS OF AN INCH INTO THE COASTAL RANGES OF WA AND OR AND ALSO FARTHER INLAND INTO THE CASCADES. SHORTWAVE ENERGY MOVING EWD WILL ALSO BRING LT TO MDT RAINS.. WITH SNOW AT THE HIER ELEVS.. THRU THE NRN INTRMTN REGION AND INTO THE NRN ROCKIES. FARTHER EAST... MSTR WILL STILL CONTINUE TO FOCUS INTO THE WEAKENING BNDRY DRAPED ACROSS THE SE. KORTY/ROBSON GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov 24HR QP VT 29/12Z 0.01 530219 532212 532204 532194 529184 525173 522166 517161 514161 513166 511172 510179 513190 516198 518206 520211 523216 529220 530219 0.01 521265 518256 515248 512238 508231 504225 500221 496219 493223 493229 495240 491237 489235 486235 484236 481236 480233 476230 472232 458234 456237 457241 465244 469246 473249 479255 483261 488269 495282 498287 501289 503292 508292 512290 0.01 465735 464730 459731 453733 445738 439743 436751 434760 434768 436772 440771 444764 449759 456751 460745 464737 465735 0.01 477788 477784 475783 472786 469795 463814 461824 459834 459845 458857 457864 457868 459882 462892 464899 466901 471902 476900 477895 479888 480878 481872 481864 478838 476826 475812 477791 477788 0.01 501063 501057 500052 497045 491036 484026 481021 478012 475994 470973 464958 461954 457953 454951 452930 448913 445900 443891 439882 433866 429846 426811 426783 424768 421752 419746 415740 411733 406726 402721 399721 396723 394729 393735 392751 392762 392775 392780 390787 389794 387802 383808 376812 364814 360815 357818 354824 350829 348834 347839 348845 346857 344868 340881 336892 331905 325918 323922 318926 309931 303938 296945 289955 287959 289964 293964 305959 310958 316953 321952 326952 332952 338951 344949 348946 354939 369917 378906 383903 387904 390910 392916 397919 398922 398951 399961 401972 403978 406981 410982 417982 420988 423005 425026 427031 431035 440040 442046 442055 442066 443072 444076 451085 453094 456101 458106 461110 466115 467116 469119 468122 467127 467133 466151 467154 470155 472152 471147 474141 479140 487139 485133 480127 474121 473116 473110 476098 475077 476068 478067 486068 491069 497070 501063 0.01 453845 453845 450846 449847 447848 445852 444854 443856 443858 444860 446861 447861 448860 449858 451855 452854 453850 453847 453845 0.01 427060 424053 418042 404049 398047 393046 389049 389054 391057 390060 389064 388067 388071 389076 393085 391098 393108 391113 391117 410114 411107 409102 400102 397096 398089 400083 406079 410076 415074 417072 418069 418063 425064 427060 0.25 507283 508278 509274 510269 510267 509264 508260 505259 502258 499257 497256 495254 494253 493253 492257 493260 493263 495267 495268 497272 497274 499277 501280 501281 504283 507283 507283 0.25 413817 412811 410806 406805 403810 400817 397828 397837 401851 406876 410887 414897 415909 415920 416927 418930 422927 424922 426913 424901 423877 421866 419851 417839 414825 413817 0.25 383857 384850 383846 381843 375846 368855 363862 359871 356881 353890 353900 356900 359898 366890 372884 378874 381866 383857 24HR QP VT 30/12Z 0.01 510679 506668 502659 498654 494646 495640 493636 489627 488625 485624 483622 478619 472617 466616 460617 454621 451621 447624 438631 431638 429641 428645 426649 425653 424660 424666 423674 415679 412679 411676 411673 408669 404667 397671 390675 383680 376687 369693 366697 362700 353711 339732 330744 327749 325754 320765 315779 312795 309807 305831 301858 291916 288928 285937 283943 281950 278962 279967 278973 281980 283981 287981 293979 301978 306980 315987 320992 325994 331992 335988 338975 339968 339958 339937 340929 343923 350915 360903 367893 372883 379871 385858 387851 389844 393830 399812 403806 406805 411810 414819 417824 420826 421831 416844 412860 411870 413875 417876 422873 430869 436870 445869 455872 459877 461886 461903 465911 470912 473908 477902 482896 487891 491883 491870 489859 487852 484846 479838 471823 463810 460803 461797 464790 469782 479771 485763 489756 493745 495743 497737 501729 504721 508703 510690 510679 0.01 540202 540197 538191 534182 524164 518155 512147 503138 495132 482123 480118 478113 479103 479091 477075 470046 457005 456999 454991 451986 449981 439963 433960 425959 420960 415963 409969 408975 408982 412992 417999 419003 422007 427016 431021 440040 444048 448058 450064 451072 453081 451089 448090 442091 434090 429088 425085 423086 421089 421095 419099 415100 407096 396113 399121 407124 412125 415127 415131 414134 411137 407139 400138 394137 391141 390147 392152 395154 400155 403159 407162 408164 408170 407177 409182 412184 413192 410198 407202 403203 398203 395203 391207 391211 393214 396218 397221 396224 389225 385227 384230 384234 385242 390249 397255 416268 423272 427279 432286 435286 437280 439274 442267 445265 451267 461270 472276 479280 488286 507299 525251 524251 523246 522245 520241 519239 517237 515233 515233 513228 513227 513223 513222 516223 517224 519226 522227 525227 526227 528227 531226 533225 534223 535221 538216 538215 0.01 419076 420071 419065 415059 410056 404053 400052 398053 391057 384058 378063 372061 366061 365066 368068 370071 371075 373082 379086 380094 384089 387090 391087 392083 395079 398081 404078 409081 415079 419076 0.01 264800 264800 261799 258800 255801 253802 250803 248805 247807 246808 245811 245812 245814 244817 247819 249816 249815 250812 250812 252808 253808 254806 257805 259804 262803 264801 264800 0.25 521269 520260 517253 511236 505220 502212 498206 491204 483203 471206 464206 456205 444209 431211 425213 422217 419221 417221 413218 410218 409221 405229 397238 397242 401245 406248 419256 425261 428263 432261 440255 447253 455253 462256 469259 477264 482268 493278 501284 506288 512286 516281 0.25 528208 530202 529197 525189 517172 513166 509159 497148 490144 484142 478137 474135 469134 464130 460128 456127 445139 437139 433145 430153 426159 422165 420170 421176 426180 428178 430174 434168 437166 442169 445176 445179 444182 442188 443192 449196 452197 454197 458189 463183 466175 474173 478175 483178 493188 504199 517205 525209 528208 0.25 448113 447109 447109 444105 443105 441102 438104 438105 435107 433108 432109 430112 431116 432117 435118 437119 440118 443117 444117 446116 448113 0.25 378747 376739 374736 369733 365732 362733 355738 350744 346754 342764 339775 341786 344796 345807 343827 332824 325849 323859 321870 319883 316896 313906 308916 306921 307925 307929 306939 306943 309942 313938 317934 330915 335906 339896 344885 352875 359867 363861 366858 372860 376856 380843 382831 384817 385811 382802 381793 381785 383768 383764 381760 379757 378753 378747 0.50 515262 514254 511246 505230 502223 499217 494212 486208 479207 473209 468210 458211 449213 440214 434216 430217 424220 423224 421229 419230 414230 411229 409231 407237 407240 408244 414248 420252 425256 428256 431254 437250 447247 454246 462247 469249 476253 482258 489265 497275 501279 505280 508279 508275 505259 507259 513265 515262 0.50 487170 488166 487164 484160 479156 473155 470153 468148 465146 462146 460148 461152 462157 465161 469165 472166 475165 478164 481166 486170 487170 0.50 367758 367754 364752 362755 361757 360758 359762 359763 358766 358769 358770 357774 359777 360776 360776 362772 362772 363767 364767 365763 365762 366758 367758 0.50 366823 365818 363816 358819 354825 350832 348837 346845 346853 346856 348855 354850 357845 361838 364831 366824 366823 0.50 343854 339848 336845 333845 330851 327858 325872 322886 319900 315914 314920 316928 320924 324918 329907 335894 340879 343864 342857 343854 1.00 501266 499262 498260 496257 495254 494253 492248 492248 489246 488247 489249 490252 491254 492258 493259 495263 495263 498266 501266 1.00 481240 479236 477234 476233 474233 473236 472237 473237 475241 478242 481240 1.00 471219 470216 467217 465217 465221 466222 466222 469220 471219 1.00 458219 455218 451219 442219 433222 429223 429229 429232 425235 416235 413238 415242 418244 422248 426250 429248 435242 433237 433233 435232 443227 451223 454223 458219 1.00 334874 334871 334867 332865 331868 330870 330872 329876 328878 326883 325892 326896 329895 330889 333879 334876 334874 1.50 427243 427242 424240 422239 419239 416240 418241 421243 424244 427244 427243 24HR QP VT 31/12Z 0.01 521270 523260 526254 527248 525239 523232 531224 533218 532209 529188 528179 526170 523163 518158 509149 487130 483127 479125 475124 463122 462104 458101 453096 449093 446093 438093 432092 428090 425091 422096 424100 421099 415101 412100 410098 407097 404098 395106 391111 393116 402124 411132 419133 421136 419139 412152 412157 410157 407158 405159 409171 407176 407183 412187 414190 415193 413202 415208 411211 407214 407221 408229 405233 403236 403240 406244 411248 419252 430260 435263 443266 457271 483279 496286 501289 504292 508293 513291 518278 0.01 515834 514828 512823 507819 500808 494805 489804 483803 477804 474808 473812 471819 468825 464831 452855 443869 437881 428891 418898 413902 405906 401909 395912 389916 383919 374927 370932 366938 364944 362951 363955 365959 369964 378969 384969 390974 389986 391995 394001 398005 401007 405007 410007 416006 430001 441996 453990 464981 472973 477968 483966 493971 501972 510969 516964 519959 522951 524942 526925 526913 525906 524900 520895 515893 510893 507889 508882 509866 513847 515834 0.01 387726 385720 381717 373718 364720 358723 350727 346729 341733 334738 330744 324761 323769 322778 325783 325787 321795 314809 302838 300844 299853 301858 299865 295882 286893 287913 284928 283934 284943 282950 279958 273972 270977 266984 256996 253002 252010 254012 258013 268012 274009 280004 285998 290991 297979 304965 307959 309951 311941 312932 312923 313914 317907 321902 331889 336883 340876 345870 349862 352854 354847 355839 355834 354828 353817 353812 355808 365796 370788 375781 382767 386755 387752 386744 38