FXUS04 KWBC 012310 PAA
QPFPFD
 
QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
609 PM EST SAT FEB 01 2003
 
FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 03/0000 UTC THRU FEB 05/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 
DAY 1...

...WRN U.S....
MDLS ARE STILL SHOWING SOME DIFFS IN MASS FIELDS OVR THE WRN U.S.
AS THE OVERALL PATN BEGINS CHANGING. STG RDGG OVR THE ERN PAC
WL SUPPORT DIGGING OF PAC ENERGY INTO INTERIOR SECTIONS OF THE
GT BASIN. THE ASOCTD SFC/8H BNDRY CROSSING THE REGION WL HELP
FOCUS MSTR AND LIFT...WHILE OVERALL W-SWLY FLOW SUPPORTS
UPSLOPE FLOW. MDLS SHOW MOD/STG 8H/7H CNVGNC ALG THE BNDRY
WITH ENHANCED CNVGNC IN THE PREFERRED UPSLOPE REGIONS OF THE
WASATCH AND CNTRL ROCKIES. SATL PW LOOPS STILL SHOW A
CONNECTION INTO THE PAC PLUME OF MSTR...BUT IT IS WEAKENING.
NEVER-THE-LESS...THE STG DYNAMICS...OROGRAPHIC LIFT AND FNTL
CNVGNC SHLD SUPPORT A BAND OF LGT/MOD PCPN THRU THE REGION
WITH POCKETS OF HVY SNOW IN THE HIER ELEVS.

...CNTRL/NRN PLNS...

...18Z UPDATE...THE ETA AND GFS WERE VRY SIMILAR TO THEIR PREVIOUS
RUNS ON THE STRENGTH OF THE MLVL TROF.  HWVR..THE ETA HAS
LOWERED THE SFC PRES ACRS THE RGN..WHICH IN TURN HAS
STRENGTHENED THE WAA PATN/MSTR ADVCTN FM THE NRN PLAINS EWD
TO THE LOWER GTLKS..RESULTING IN A SGFNT INCREASE IN QPF.  EVEN
THO THE GFS IS NRLY IDENTICAL TO ITS ERLIER RUN WITH ITS SFC
PATN..IT
ALSO HAS INCREASED THE PCPN AMTS HERE.  SO..HAVE OPTED TO RAISE
THE QPF SOME..RESULTING IN A VRY NARROW BAND OF MDT AMTS FM S-
CNTRL SD EWD OVR SRN MN TO SWRN WI...     

MID/UPR LVL MSTR ALG WITH WEAK MLVL ENERGY WL STREAM EWD ALG A
WEAK 8H/7H BAROCLINIC ZONE. THIS SHLD SUPPORT A BAND OF LGT TO
MDT MIXED PCPN THRU THE REGION. THE MDLS ARE FAIRLY AGREEABLE
WITH THE OVERALL ZONE OF PCPN.

...NEW ENG...
MDL INCONSISTENCY IN THE ETA AGAIN LEADS TWD THE GFS FCST FOR
THIS PD. THE 12 UTC GFS IS VRY CLS TO THE 00UTC RUN...WHILE THE
ETA
HAS COME INTO MUCH BETTER AGREEMENT WITH THE GFS. THE STG MLVL
VORT ALG THE MID ATLC CST THIS MRNG WL CONT TO DEEPEN AND BCM
NEG TILTED AS IT LIFTS NEWD TWD THE CANADIAN MARITIMES. THIS WL
INDUCE STG CYCLOGENESIS OVR THE WRN ATLC WITH THE SFC LOW
LIFTING NEWD AND SPREADING MOD/HVY PCPN OVR MUCH OF ERN NEW
ENG. LATEST SATL PW LOOPS SHOW THIS SYS STARTING TO TAP SOME
SUB-TRPCL MSTR THAT IS AIMED INTO DOWNEAST ME. WARM AIR ALREADY
IN PLC ALG THE CST WL MAKE THIS A DIFFICULT PCPN TYPE FCST FOR
THAT AREA. SEE QPFHSD FOR ADTNL HVY SNOW/ICING FCSTS. FOLLOWED
THE GFS QPF FCSTS QUITE CLSLY DUE TO ITS RUN-TO-RUN CONSISTENCY.

DAY 2...

IN THE NORTHWEST...  THE ETA IS STICKING TO ITS GUNS AS FAR AS
TAKING THE CANADIAN SHORT WAVE SHARPLY SWD ON A TRACK WELL TO
THE WEST OF THE GFS.  THE GFS HAS BEEN FLIPPING BACK AND FORTH...
WITH ITS PREVIOUS 00Z RUN HAVING TAKEN A MORE WESTERN TRACK...
BUT ITS LATEST 12Z RUN GOING BACK TO THE EAST.  OTHER MODELS
SUGGEST A COMPROMISE WOULD BE THE BEST WAY TO GO AT THIS TIME.
THEREFORE... HAVE GONE WITH A BLEND ON THE PCPN... WITH LIGHT BUT
SIGNIFICANT AMOUNTS IN BOTH THE CASCADES AND THE NRN ID ROCKIES.  

UPDATE... THE 18Z ETA HAS BACKED OFF ON THE WESTERN TRACK OF THE
SHORT WAVE DROPPING SWD FROM CANADA.  IT IS NOW CLOSE TO THE
COMPROMISE PATH...BETWEEN THE 12Z ETA AND 12Z GFS  DESCRIBED
ABOVE.  THIS GENERALLY SUPPORTS THE ABOVE SCENARIO... BUT HAVE
DECREASED WESTERN EXTENT OF LIGHT AMOUNTS IN OR SOMEWHAT.  

IN THE CENTRAL ROCKIES...  THE ETA IS INITIALLY SLOWER THAN THE
GFS
WITH THE SHORT WAVE SYSTEM MOVING THRU THE SOUTHWEST.  THIS IS
PROBABLY BETTER FOR THE FIRST HALF OF THE PERIOD... WHEN THE
SYSTEM IS MOVING THRU THIS REGION...  SINCE THE TREND HAS BEEN
SLOWER.   EXPECT LOCALLY MDT AMOUNTS IN THE UPSLOPE PORTIONS OF
S CENTRAL CO.

IN THE MID/LOWER MS VALLEY...  THE SHORT WAVE SYSTEM FROM THE
SOUTHWEST WILL BE DEVELOPING PCPN HERE DURING THE SECOND HALF
OF THE FORECAST PERIOD.   THE ETA SYSTEM IS EXPECTED TO CATCH UP
WITH THE INITIALLY FASTER GFS DURING THIS PERIOD.  HOWEVER...
THERE
IS QUITE A DIFFERENCE BETWEEN THE TWO MODELS WITH RESPECT TO
THE INTENSITY OF THE SYSTEM AND THE AMOUNT OF PCPN.  THE STRONG
UPSTREAM SHORT WAVE IN THE ETA RESULTS IN A MORE WESTERLY
SHEARING   500MB FLOW INTO THIS SYSTEM.  THIS KEEPS THE SYSTEM
RELATIVELY WEAK... AND PCPN ON THE LIGHT SIDE.  THE GFS... ON THE
OTHER HAND... IS NOT DIGGING THE NW SYSTEM AS SHARPLY SWD.  AS A
RESULT... IT HAS A MORE NRLY 500MB FLOW COMING INTO THE WEST SIDE
OF THIS SYSTEM...  WHICH CAUSES IT TO BE STRONGER THAN IN THE
ETA...
WITH HEAVIER AMOUNTS OF PCPN.  WITH THE OTHER MODELS KIND OF
SPLIT ON THE NW SYSTEM... HAVE DECIDED THAT A COMPROMISE IS IN
ORDER FOR THIS DOWNSTREAM SYSTEM.  THEREFORE... HAVE
COMPROMISED WITH THE AMOUNT OF PCPN IN THE LOWER/MID MS
VALLEY.

IN THE SRN GREAT LAKES... THE MODELS HAVE A WIDE RANGE OF
SOLUTIONS REGARDING THE INTENSITY OF A NRN STREAM SFC LOW IN
THE REGION.  BELIEVE THE SFC DEVELOPMENT SHOULD BE ON THE WEAK
SIDE SINCE THE UPPER IMPULSE IS MOVING THRU A CONFLUENCE ZONE. 
HAVE USED AN ETA/GFS BLEND FOR PCPN AMOUNTS... SOME OF WHICH
COULD BE LOCALLY MDT.

DAY3... 

IN THE NORTHWEST...  HAVE CONTINUED TO USE A COMPROMISE BETWEEN
THE 12Z ETA AND GFS REGARDING THE  SHORT WAVE DROPPING SWD
THRU THE ROCKIES.  DURING THIS PERIOD THE ETA IS FASTER AND
STRONGER WITH THIS SYSTEM.  RESULTING PCPN PATTERN IN QPF IS A
BLEND OF THE TWO PCPN FORECASTS.   
  
IN THE EAST...  BIG DIFFERENCES IN WHAT IS HAPPENING AT 500MB OVER
THE NATIONS MID SECTION BY LATE IN THE PERIOD.  THE ETA HAS MORE
NRN STREAM TROFFING DROPPING SWD THRU THE GREAT LAKES AND
PHASING WITH THE MORE SRN STREAM SHORT WAVE THAT IS CARRYING
LOW PRESSURE NEWD FROM THE MS VALLEY TO THE NORTHEAST.  THE
GFS... ON THE OTHER HAND... IS BRINGING ADDITIONAL SHORT WAVE
ENERGY EWD THRU THE SRN STREAM TOWARDS THE MAIN SYSTEM. 
AMAZINGLY ENOUGH...THE PRIMARY SYSTEM IS FAIRLY SIMILAR IN THE
TWO MODELS BY THE END OF THE PERIOD... WITH A DEEP SFC LOW
VICINITY OF NRN VT/NH.  THE GFS PCPN PATTERN IS A LITTLE SLOWER
THAN THE ETA AND FARTHER TO THE NW WITH BEST AMOUNTS.  HAVE
GENERALLY COMPROMISED BETWEEN THE TWO.  MDT TO LOCALLY HVY
AMOUNTS ARE EXPECTED FROM THE OH VALLEY NEWD ACROSS MUCH OF
THE NORTHEAST. 
 
ECKERT/WOLF/LINDNER

GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov
24HR QP VT 03/00Z
 0.01 509647 506639 502634 492626 483621 473617 464615 456617
452618 
      447623 441626 437627 430628 427628 421631 418632 413637
409644 
      407646 403648 396650 385658 376666 369675 364686 363691
360695 
      358701 357709 358720 362732 367742 370747 373750 380754
387755 
      407746 410748 414752 416758 416764 414768 410773 402781
396784 
      392787 386791 381796 374804 371811 373814 377814 380813
388810 
      392810 394817 396824 399835 401846 405855 408865 409873
410882 
      414894 418908 422919 423933 424952 424965 423975 421983
418993 
      414003 410013 405022 395039 389057 385060 382063 379065
375065 
      371064 369065 370075 370083 371092 372097 372106 371111
368115 
      360116 357119 356125 357130 362139 364143 364149 362157
364162 
      368163 374158 377157 379159 380162 381169 378178 367178
357180 
      356183 357188 362189 367193 370197 375202 382209 389213
393216 
      399218 404215 404207 406199 410189 413185 417183 420184
422183 
      423177 422171 422166 425162 425156 425150 424147 425140
427135 
      428131 431128 435124 441123 443125 443129 436140 435148
435156 
      441160 446162 447166 447171 445179 442184 441188 442192
443195 
      448192 452192 458185 462182 464178 464175 464170 466169
471168 
      473167 478166 482165 484161 481155 476151 474146 474145
480142 
      483140 485134 483129 476127 471128 466132 461132 457130
454127 
      454123 457118 461114 465113 468112 469109 467101 466095
466085 
      467069 467053 467036 466008 465976 459950 458941 458931
455911 
      452891 450882 448872 445866 443859 438848 427827 416806
414802 
      416799 421796 426793 432789 436787 443785 447783 452782
458779 
      463776 469771 473767 477760 476753 474748 469744 463743
459743 
      448744 439740 437737 436731 440729 444730 451732 457731
461728 
      468725 476720 483716 488711 493706 495703 501692 505684
507680 
      510670 510661 509647 
 0.01 514286 512270 516268 518264 518258 508231 495207 491204
486204 
      480204 476204 471206 458209 449213 443216 440219 440224
443228 
      447228 455231 454231 448232 443235 442237 442241 448242
452241 
      460243 468245 475249 479253 481258 485268 487274 491279
495282 
      498283 504289 507291 510290 514286 
 0.01 491234 491234 489229 489229 486227 483226 480225 477225
474224 
      474224 474225 476229 477229 479231 482234 485232 488233
491234 
      491234 
 0.25 454006 453994 452982 453969 452956 451943 449931 444908
442896 
      438883 431863 425847 422844 419844 418847 421859 422865
423873 
      424884 428909 430921 432933 433946 433956 433004 433028
434034 
      435038 438047 441053 440057 435057 431049 426043 423044
421047 
      416052 411056 404060 394074 395079 397081 402081 407082
411086 
      412091 408092 406095 403103 381119 377123 373126 372129
375137 
      376138 379134 381131 384129 392124 397124 399129 402129
408125 
      411124 414126 417128 420128 423127 426124 428120 431117
434115 
      439113 447113 449107 448101 443096 439093 434094 430088
428085 
      427080 430076 435075 439076 443077 450083 454083 455076
455069 
      454063 450056 449052 450047 451039 453018 454006 
 0.25 501650 498643 494638 488633 483630 475628 469628 462630
454634 
      448637 440642 432641 427643 419650 417658 410662 404662
401663 
      399666 398671 400674 403681 398689 395695 394700 395706
394713 
      390720 384728 382730 383734 385735 390735 398731 405725
415720 
      422718 434716 443715 450715 456714 464710 482696 490688
494681 
      497672 500662 501650 
 0.25 412153 412151 410149 409148 407148 406148 404151 404155
406158 
      408156 409156 412153 412153 
 0.25 383196 381195 378195 378195 378196 381198 383196 
 0.50 422115 417113 412113 411106 409101 406103 404110 400110
394113 
      391116 391118 397117 403121 408120 414121 419119 422115 
 0.50 495656 494650 492645 487638 480634 475633 470634 461635
454640 
      449645 444648 439648 434647 429648 427649 425653 425659
424666 
      425672 425676 422676 418677 413688 405696 404700 405704
408709 
      412711 416712 421712 428709 437707 444702 446700 450699
458703 
      463701 469697 480688 486682 490676 494664 495656 
 0.50 447953 443929 440914 439908 437902 436896 434902 433911
436926 
      437939 438963 439978 441988 443995 443002 442011 440023
439029 
      440036 441040 444039 446034 446027 446016 446003 447990
446982 
      447957 447953 
 0.50 447072 447072 444070 441069 441072 441072 444074 447072
447072 
 0.50 439104 439100 438099 435099 432096 432096 430093 429092
427089 
      425092 427094 428096 429098 431100 432102 434103 433105
433106 
      431107 429107 427106 425107 426109 429109 432108 435109
438108 
      438107 439104 
 0.50 427064 428060 427056 427056 424053 421055 420056 420060
420064 
      421066 424066 427064 427064 
 0.50 414072 412069 412068 410065 407066 404068 406072 407073
410075 
      412074 414072 
 1.00 480654 478647 476645 469644 463645 457650 453655 447658
445666 
      446670 453673 458675 464682 467683 470681 474678 477674
480665 
      480656 480654  
 
24HR QP VT 04/00Z
 0.01 495607 486594 477579 475575 472574 469571 466573 459579
453587 
      450594 444603 440607 434612 430616 426623 423630 421638
420652 
      420659 423666 440688 444697 444703 442716 439728 434738
433740 
      430739 427733 422727 418724 413725 406730 402745 393774
384799 
      376819 372828 367839 360848 353858 337877 329886 322895
319899 
      316907 314920 313932 316938 321941 336942 341943 347947
353953 
      358962 362973 362980 360984 356991 354997 350010 347024
346033 
      346041 347049 350056 355066 359072 361075 362079 357082
351085 
      349089 352096 355101 361106 362109 361113 360115 357114
351110 
      348110 345116 347120 351124 356126 363126 368125 372119
374115 
      376114 380112 383112 379121 375126 375130 377130 382127
385126 
      397121 399115 400113 403112 405118 413119 421120 430122
436119 
      439120 440124 438129 433136 431143 431149 431154 434160
437165 
      441171 443174 443178 438181 435188 437197 440203 443206
447206 
      449204 451200 455195 459191 467183 472182 476183 479185
480190 
      478194 468201 459211 455215 454219 456223 460224 467225
475228 
      474230 470230 465231 462233 463240 465246 471251 481262
485266 
      488269 492273 496278 502282 507282 509278 511275 515266
518254 
      515239 511226 508219 508215 512215 516217 522216 531208
533198 
      535186 535179 533173 529165 526159 521153 500129 491118
485103 
      484099 481094 472086 468083 465076 463070 462063 459055
454051 
      446051 438051 435052 429050 425045 423041 419025 417020
415011 
      415969 412964 406958 406953 409946 415933 421919 424916
428920 
      429926 432934 438944 441946 444941 447932 449927 453924
456924 
      461926 470937 476946 477951 479954 483960 486960 490957
493952 
      498946 503941 507940 511941 518943 539957 549962 553961
555956 
      558943 558932 559924 559918 560911 559903 559897 559890
557879 
      555863 552851 549848 545846 535844 514840 492836 480835
473835 
      467831 459821 454812 451803 440761 444748 449733 452729
457722 
      461719 466716 486715 491714 498711 508708 512707 518704
520697 
      521691 521676 518665 
 0.01 442088 441086 440084 438084 436082 433081 430082 427083
426084 
      427085 429088 430089 432092 433092 433092 435091 438089
441089 
      442088 
 0.01 427096 424092 422088 419084 416080 412079 409080 406083
405087 
      407088 412091 415095 415099 418102 421101 425099 427096 
 0.25 509648 502632 497622 493615 488608 486607 480607 471613
462615 
      454619 445624 440629 437635 436640 436644 440652 443656
450664 
      464684 471691 479695 487695 495693 505689 509687 514681
515675 
      514669 512661 510652 509648 
 0.25 476163 478159 478155 476150 473145 468142 462