FXUS04 KWBC 102147
QPFPFD
 
QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
446 PM EST MON FEB 10 2003
 
FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 12/0000 UTC THRU FEB 14/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 

NO CHNGS IN THE LATEST MDL RUNS. SLGT QPF CHNGS DUE TO ONGOING
RDR/SATL TRENDS.

DAY 1...

...EAST COAST.....

THE MODELS ARE IN PRETTY GOOD AGREEMENT IN RACING THE SFC LOW
DEVELOPING OFF THE NC COAST RAPIDLY ENEWD FAR ENOUGH OFF THE
COAST TO KEEP THE STRONGEST WARM ADVECTION AND LIFTING OVER
THE ATLANTIC.  WK WARM ADVECTION EARLY IN THE PD FOLLOWED BY
LIFTING ALONG THE ARCTIC FRONT SHOULD PRODUCE LIGHT SNOW
ACROSS NRN NEW ENGLAND.  

...NRN ROCKIES SEWD THRU THE NRN-CNTRL PLAINS AND MS VLY TO THE
OH VLY AND CENTRAL APPALACHIANS....

WK IMPULSES WITHIN THE CYCLONIC FLOW AROUND THE POLAR VORTEX
OVER CANADA WILL MOVE RAPIDLY IN THE FAST FLOW.  ONE VORT IS
EXPECTED TO PRODUCE VERY LIGHT SNOW AS IT RACES ACROSS THE OH
VALLEY TO OFF THE EAST COAST BY THE END OF THE PD.  THE GFS IS
LITTLE MORE GENEROUS WITH THE AREAL EXTENT OF THE MEASURABLE
PCPN THAN THE ETA.  SUSPECT THAT IT IS OVERDOING THE COVERAGE....A
COMMON PROBLEM WITH THE GFS IN THE COLD AIR.  A SECOND IMPULSE
IS FCST TO DROP A FRONTAL BAND AND WK CLIPPER TYPE SYSTEM FM
THE NRN PLAINS TO UPPER MS VALLEY.   WARM ADVECTION IN ADVANCE
OF THE FRONT AND PVA RIGHT ALONG IT SHOULD HELP PRODUCE
ANOTHER AREA OF VERY LIGHT SNOW.  

....CA.....

THE STRONG MID LEVEL CIRCULATION WELL OFF THE CA COAST SHOWS
LITTLE MOVEMENT ON THE LATEST SATELLITE IMAGERY.  THE GFS IS MORE
GENEROUS WITH ITS PCPN DURING THE DAY TMW THAN THE ETA.  WE
SUSPECT THE DRIER ETA MAY BE THE BETTER BET SINCE THE LOW LEVEL
FLOW REMAINS OFFSHORE SUGGESTING THAT THE LOW LEVELS WILL
STAY DRY.  


DAY 2...

SW U.S...

LATEST MODEL GUIDANCE CONTINUE TO SHOW GRADUAL PROGRESSION
OF SRN STREAM UPR TROF TOWARD SRN CA THIS PD...WITH ONLY SLIGHT
DIFFERENCES IN TIMING.  THE MORE SIGNIFICANT ISSUE IS THE TIMING
OF
WEAKER IMPULSES EJECTING OUT OF THE UPR TROF AND THEIR IMPACT
ON PCPN...ESPECIALLY ACRS SRN CA.   MODELS SHOW LITTLE RUN TO RUN
SKILL WITH THESE IMPULSES..ESPECIALLY THE WEAKER ONES FCST TO
ROTATE INTO SRN CA.   MUCH OF THE MORE SIGNIFICANT
PCPN...ESPECIALLY IN THE GFS...SEEMS TO BE TIED TO THESE IMPULSES.

THE 09Z ENSEMBLES SHOW A WIDE RANGE OF SOLNS WITH REGARD TO
AMOUNTS AND PLACEMENT OF HIER QPF..NOT UNLIKE THE SPREAD SEEN
IN THE 12Z OPERATIONAL RUNS..AND SUGGEST A LOW DEGREE OF SKILL.  
GIVEN SUCH LARGE DISCREPANCIES IN PCPN..HAVE TENDED TO TAKE AN
ENSEMBLE MEAN APCH ON PLACEMENT OF HEAVIER RAINS WITH
SUGGESTS HIEST PCPN AMOUNTS OVER SRN CA...WHILE BEEFING
AMOUNTS UP IN THE SAN GABRIELS AND SAN BERNARDINO MTNS WHERE S
TO SWLY FLOW WILL PRODUCE FAVORABLE UPSLOPE CONDS.   EXPECT
GENL AMOUNTS OVER MUCH OF SRN CA TO BE IN THE .50 TO 1 INCH PLUS
RANGE.  BACKED OFF HIER QPF AMOUNTS IN THE GFS NEAR THE CNTL PAC
COAST GIVEN PREDOMINANTLY OFFSHORE FLOW.

GT LAKES..OH VALLEY..NE...

BROAD NW FLOW SHOULD CONTINUE WITH ADDITIONAL CLIPPER TYPE
SYSTEM SPREADING MAINLY LIGHT SNOWS THRU THE REGION BEFORE
LOW PRES DEEPENS OFF THE NEW ENGLAND COAST ON WED.  FAST
MOVEMENT OF SYSTEM SHOULD KEEP SNOWS GENLY LIGHT...THOUGH
NWLY UPSLOPE CONDS BEHIND THE FRONT COULD PRODUCE SOME .25
INCH AMOUNTS OVER THE CNTL APLCNS. 

DAY 3...
MAIN ACTION WILL CONTINUE TO BE IN THE SW U.S.  AS UPR TROF
GRADUALLY OPENS UP AND MOVES INLAND ACRS CA.   THE GFS SEEMS TO
HAVE SIGNIFICANT FEEDBACK PROBLEMS AS DVLPS A LOW OVER SRN NV
EARLY IN THE PD AND SPREADS MDT TO HEAVY QPF INTO THE SRN GT
BASIN.  OTHERWISE...CONTINUED PROGRESSION OF UPR TROF AND BROAD
SW FLOW AHEAD OF IT SHOULD CONTINUE TO SPREAD DEEP LAYERED PAC
MSTR ENEWD ACRS THE DESERT SW AND EVENTUALLY INTO PARTS OF
THE SRN PLAINS.    BASICALLY THREW OUT THE GFS THIS PD THRU PARTS
OF THE SRN GT BASIN IN VIEW OF FEEDBACK PROBLEMS AND USED A
BLEND OF CANADIAN..UKMET...AND ETA MASS FIELDS TO MODIFY QPF. 
THIS ARGUES FOR INCREASING AMOUNTS ACRS MUCH OF AZ AND
ESPECIALLY THE SW FACE OF THE MOGOLLON RIM WITH A LARGE AREA OF
.50 TO 1 INCH LIQUID AMOUNTS EXTENDING NWD INTO SW UT.  
ELSEWHERE HAVE INCLUDED .50 TO 1 INCH AMOUNTS ACRS THE SIERRAS
AS MODELS SHOW MOIST SW FLOW AHEAD OF WEAKENING MID LEVEL
CENTER TRACKING EWD ACRS CNTL CA.   HEAVIER..RAINS ALSO PSBL
ESPECIALLY EARLY IN THE PD OVER SWRN CA IN DIFFLUENT REGION
AHEAD OF UPR TROF.  MODELS SHOW SOME INSTABILITY WORKING INTO
THIS REGION LATE IN THE PD WHICH COULD ENHANCE PCPN LOCALLY.  

ELSEWHERE...LIGHT LAKE EFFECT SNOWS SHOULD CONTINUE OVER THE
GT LAKES REGION UNDER CONTINUED NW FLOW AND COLD ADVECTION.      

ECKERT/JUNKER/SULLIVAN

GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov
24HR QP VT 12/00Z
 0.01 545173 547155 550147 550137 548128 547123 542110 536100
529092 
      527087 524079 522074 520066 517054 515050 507029 503014
502000 
      504985 506971 508953 505940 501926 496903 494881 494857
492831 
      487805 475790 459790 450788 446779 448768 456756 465738
474714 
      480694 478678 468666 463653 462639 460625 457620 453615
446611 
      442610 437612 431615 423622 411639 407646 404651 400661
393680 
      390690 388700 390711 393719 400728 409735 415740 417743
419746 
      420753 420760 419765 417770 415770 406770 397777 391784
386788 
      382792 372805 368809 365812 362816 361820 358823 357827
359832 
      363834 366835 370840 373845 374853 373874 373886 375894
377899 
      388912 394938 398947 403955 409962 416966 419967 421967
422955 
      416941 410919 404893 399872 397856 398840 404830 411824
419820 
      426824 426836 419849 413857 412868 414879 419897 427928
430941 
      436964 439974 444984 448993 453003 456014 458021 459027
459035 
      457040 456044 454045 450041 445034 439033 436038 436047
438052 
      442058 443061 442065 440068 441074 447081 462080 467083
470088 
      470096 473101 480107 488112 496115 502114 508116 514116
518120 
      524133 527147 526153 524156 516161 513167 510169 506168
504168 
      502172 504178 509187 522199 531205 534205 537196 545173 
 0.01 491139 489136 488134 486132 484130 482129 481129 478128
475127 
      472127 471128 470132 470136 470141 471142 474142 476142
477141 
      480141 483142 486143 489142 491139 
 0.01 470115 470106 467103 460102 457101 454097 450095 445097
441098 
      435097 432096 431100 428104 423105 423112 422115 423117
429117 
      432119 434116 438114 440114 443116 446120 449120 451117
455114 
      458112 464114 467115 470115 
 0.01 427064 427059 424057 415057 407057 402058 398058 391061
389064 
      387068 387075 390079 394081 398081 404079 410076 414074
417072 
      422068 427064 
 0.01 376195 376193 375191 373188 372187 371186 368184 365183
363182 
      362181 360180 359181 360183 360185 362187 365188 365189
367190 
      370192 373193 375195 375195 376195 
 0.01 346203 346196 345192 342188 339184 334179 330177 326178
321181 
      319183 319187 322191 327196 332201 336206 338208 341209
345203 
      346203 
 0.25 443648 440643 437639 432640 427644 423649 418655 413664
410674 
      409685 412692 416695 419695 425693 430689 432685 440674
442671 
      444666 445660 444652 443648 
 0.25 400791 399791 396792 394794 391795 388797 387798 386800
384802 
      382804 385806 387804 390802 392800 395798 397797 397796
399793 
      400791 
 0.50 436655 435654 433652 431652 428653 426656 424660 424660
422663 
      421667 421668 420672 420673 420677 422680 423680 425678
428676 
      429674 430672 432669 433666 433665 435661 435659 436655
436655  
 
24HR QP VT 13/00Z
 0.01 516773 515769 509772 506770 502764 503758 501753 496746
490726 
      487723 482722 484712 484707 482697 480690 477684 470673
466667 
      455659 450657 442654 434652 427652 424653 419657 416664
412672 
      409680 405693 404698 400704 394712 381722 379726 378731
379737 
      378744 375753 375757 377761 384764 397765 400770 399773
397779 
      392784 383790 373797 368803 364809 360815 353827 349833
348836 
      347841 352843 356843 361840 365841 372846 376851 385859
388866 
      388875 389882 393887 399893 404897 410899 425899 433898
441896 
      447893 453891 459896 462898 466899 473899 475903 479904
482905 
      484900 485895 485885 486876 487870 489866 492861 495853
498843 
      503828 509808 513798 515794 517789 516773 
 0.01 516086 516077 516072 514069 511066 508063 503059 497063
496068 
      497072 498077 500081 503086 505090 508091 511091 516086 
 0.01 440688 440688 436687 436687 434688 434691 432694 430696
429696 
      431700 431700 434699 437700 438700 439699 439695 440693
440690 
      440688 
 0.01 402205 397197 393191 391188 391185 394179 398172 398162
397156 
      395148 380122 373111 366101 361096 357095 356099 358106
357108 
      353108 349106 346101 345082 342073 339066 336061 329059
318062 
      313067 310073 307081 303087 301094 300102 297107 292108
285109 
      276108 273108 269110 265115 262122 259125 250131 242139
244144 
      248148 258155 266160 270163 274170 281181 290189 301197
310202 
      324209 336216 349224 358230 368241 375243 379244 381243
384238 
      386234 385230 383223 384215 385212 389211 394209 399207
402205 
 0.25 417790 416787 411788 405790 399792 394796 389800 386802
390802 
      395800 399800 405801 408803 412804 414800 416795 417790 
 0.25 374187 371182 368178 364174 361171 358174 351169 348163
346158 
      354156 355152 349151 346153 341152 338152 331151 329156
323156 
      309153 301155 299161 301166 306175 309179 313183 322191
330199 
      340204 345207 352209 357212 361216 365218 368213 364203
361197 
      362193 373191 374187 
 0.25 356138 357135 356132 355131 353130 351128 349127 348126
345125 
      343126 344130 345132 345134 347136 350137 350137 353139
356138 
      356138 
 0.50 363182 363181 360180 358181 360182 363182 363182 
 0.50 357184 349178 345166 340161 336163 324161 318159 311159
311162 
      313167 319177 325187 334193 343201 347202 351201 352200
350193 
      350190 357184 
 1.00 347193 347189 346182 345178 344173 342167 340167 336168
330167 
      325168 324171 326175 329178 332180 337183 340184 342189
344192 
      347195 347193  
 
24HR QP VT 14/00Z
 0.01 479865 477857 476852 471847 467841 463828 458817 451807
444798 
      440791 438788 438784 439778 445768 449756 449750 448747
444744 
      439743 435745 429745 424747 424752 424760 423766 419775
414779 
      409782 402785 396789 389796 388801 391803 402802 406803
410806 
      412813 414821 417822 418819 421814 423809 425806 429811
431816 
      437826 444832 448839 447844 445845 439849 434852 429852
425849 
      423848 422850 419855 419859 419864 421867 425869 433872
439871 
      446870 451866 455862 456859 459862 460868 463882 465897
469900 
      470900 475895 477889 479875 479865 
 0.01 429231 432223 432216 432211 430205 426193 425175 424171
422166 
      415157 414152 412148 410141 411137 416135 419130 421126
421119 
      417108 410096 405088 403084 403076 402072 400070 395068
390065 
      386065 377059 369057 365051 363046 360034 359027 358018
359007 
      361995 362981 364975 364969 365958 363949 361945 352937
345932 
      336929 332928 328931 327937 327945 327949 325954 321956
318960 
      317972 318981 320987 320993 314993 311993 304992 298992
293996 
      290999 288003 286009 286012 288015 294022 303028 306031
307036 
      304043 292059 287066 280071 275074 272077 269081 268086
268098 
      271105 274111 277114 283121 283125 280125 277124 270120
264119 
      262122 261129 263134 277145 277156 278161 281165 309192
322205 
      335218 342225 350231 356233 361235 371237 377238 384241
392244 
      404249 410250 414249 418246 423240 429231 
 0.25 405232 407223 407217 404208 403204 401201 395199 392197
389195 
      380185 372177 366173 361173 358173 353175 349173 348170
344165 
      339162 334159 331156 332153 335150 341147 346146 354146
366144 
      368152 370158 374162 376162 380159 381152 382148 381143
381137 
      384130 387125 387120 387116 382111 378104 375099 371099
369097 
      361088 349085 341082 337078 333075 329073 325073 318075
313078 
      303081 296084 293088 291095 290100 296110 303120 305127
305137 
      300151 302156 306161 313170 321178 330188 335198 338204
342207 
      359209 363210 366216 369221 374226 380231 392234 402235
405232 
 0.25 413176 413176 410173 408175 410178 413176 413176 
 0.25 348006 349997 349989 348980 346972 343969 341973 339976
335976 
      333977 333981 332988 331995 330001 328004 326005 316006
314007 
      316013 322022 326025 332025 336024 340021 345016 347010
348006 
 0.50 398219 401216 400212 397208 391202 384196 376188 371183
366181 
      360181 357184 362188 367193 374202 377206 379210 381218
383220 
      386220 389219 398219 
 0.50 380126 381123 379120 372121 369121 366119 363117 349100
342094 
      338091 332089 329092 324095 319096 315098 307104 304107
305110 
      309114 313115 317113 321115 320118 314119 312127 313134
318141 
      324145 327140 332138 344139 347141 354142 358140 361137
365135 
      370136 375139 377133 380126 
 0.50 350197 348188 346178 344171 342167 333163 325159 320158
317156 
      312156 312157 314160 316167 321172 328179 334186 338193
341197 
      346199 350197 
 1.00 392210 391208 390205 389205 386202 385201 384200 381197
380196 
      378194 376193 374194 375197 376199 378201 379203 380204
383206 
      385208 385208 388210 391210 392210 
 1.00 341181 342178 341175 340174 338171 337170 336169 333169
331169 
      331172 332175 333176 334180 335180 337183 340183 341181 
 1.00 344109 343108 341109 343113 344109