000
FXUS04 KWBC 030728
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
227 AM EST TUE FEB 03 2009


PRELIM DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 03/1200 UTC THRU FEB 06/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR

DAY 1...

...CSTL SXNS FM THE MID ATLC INTO NEW ENG...
AFT A COUPLE OF DAYS OF SOMETIMES SIGNIFICANT MDL DIFFS..ALL OF
THE 00Z MDL RUNS HAVE FINALLY COME INTO VRY GOOD AGREEMENT IN
THEIR HANDLING OF THE AMPLIFYING AND SLOLY PROGRESSIVE ERN U.S. H5
TROF AND THE ASSOCTD PCPN WITH IT.  ALL OF THE MDLS HAVE NOW
CONVERGED ON THE FACT THAT MAJOR SFC DVLPMNT ASSOCTD WITH THIS
DIGGING H5 TROF WL OCCUR WELL OFF THE E CST THIS PD..WITH THE SFC
LOW MOVG FM WELL OFF THE NC CST AT THE START OF THE PD TO SE OF
NOVA SCOTIA BY TUE EVE AND CONTG NEWD THEREAFTER TUE NGT.  THIS WL
KEEP THE DEEPER MSTR AND HVIEST PCPN WELL OFFSHORE..BUT SVRL
IMPULSES ROTATING THRU THE H5 TROF SHLD PROVIDE ENUF LRG SCALE
LIFT TO SUPPORT MSTLY LGT WTR EQUIVALENTS ALG THE WRN EDGE OF THE
BTR ATLC MSTR FM DE NNEWD INTO CSTL SXNS OF NEW ENG.  LATEST NAM
AND GFS QPF SOLNS ARE IN VRY GOOD AGREEMENT..AND HAVE THE SUPPORT
OF THE 00Z CANADIAN GEM AND UKMET HIRES MDLS..SO SEE NO REASON TO
GO AGAINST THESE SOLNS.  MSTLY XPC 0.25-0.50 INCH WTR
EQUIVALENTS..XCP PTNS OF SERN MA AND CAPE COD AND EXTRM ERN
ME..WHERE SOME SLGTLY GTR THAN 0.50 INCH AMTS ARE PSBL.  PLS SEE
THE LATEST QPFHSD FOR DETAILS ON THE SNOWFALL POTNL.


THE ONLY OTHER PCPN THIS PD WL BE FM THE GTLKS SSEWD INTO THE
CNTRL APLCHNS..UNDER THE STG AND VRY SLOLY PROGRESSIVE H5
TROF..WITH MSTLY LGT PCPN TOTALS XPCD.  BTR CHC FOR A STRIPE OF
SOMEWHAT HVIER SNOWS WL BE FM WRN MI SSEWD INTO ERN IN..SWRN
OH..NRN KY AND INTO SRN WV..NR TRACK OF S/WV ENERGY DROPPING INTO
THE BACKSIDE OF THE TROF.


DAYS 2 AND 3...

...CA/OR/ID/GREAT BASIN/WESTERN CO-WY-UT RANGES...

A CLOSED UPR LOW WILL DRIFT EAST TOWARDS THE CA COAST.  MODELS ARE
IN BETTER THAN AVERAGE AGREEMENT TIMING-WISE...WITH NAM SLOWER
THAN THE ECMWF/ECMWF ENSEMBLE MEAN/GFS/NCEP GLOBAL ENSEMBLE
MEAN/SREF MEAN.  A BLEND OF THE 12Z-0Z ECMWF/00Z GFS/21Z SREF/00Z
GEFS/00Z NAM WAS USED TO MITIGATE DIFFERENCES IN QPF.  ONE
TARGETED AREA WAS IN NORTHWEST CA AS PERSISTENT AREAS OF LOW LEVEL
CONVERGENCE DRIFT ONSHORE IN ADVANCE OF THE LOW LEVEL CIRCULATION.
 ANOTHER IS IN SOUTHERN CA WHERE MOIST ONSHORE FLOW FROM NEAR THE
END OF DAY TWO INTO EARLY DAY THREE (THU) SUPPORT SHOWERS IN THE
TERRAIN WHERE THE FLOW TURNS UPSLOPE.  AREAS OF DIVERGENCE ALOFT
SUPPORT ASCENT UNTIL THEY MOVE FURTHER INLAND AND ONSHORE FLOW
WEAKENS THE LATTER HALF OF DAY THREE.  THE GFS AMOUNTS WERE HIGHER
THAN THE OTHER MODELS DUE TO A TEMPORARY PEAK IN LOW-MID LEVEL
CONVERGENCE...AND BLENDING WITH THE OTHER MODELS WAS DONE TO
MITIGATE THE UNCERTAINTY.

THE 00Z MODELS SHOW A PIECE OF THE UPPER LEVEL TROUGH EJECTS EAST
FROM THE UPPER TROUGH AND MOVES INLAND. THIS ALLOWS MOISTURE
FLUXES TO CONTINUE INLAND TO THE RANGES OF NORTHEAST
OR/ID/UT/ID/WESTERN WY ON THE LATTER HALF OF DAY THREE. AN UPPER
LEVEL JET STREAK CROSSING NORTHERN AZ AND SOUTHERN UT-CO SUPPORTS
POCKETS OF DIVERGENCE ALOFT CROSSING THE WASATCH...COMBINING WITH
THE MOISTURE FLUXES TO PRODUCE SNOW THERE AND THEN CONTINUING INTO
WESTERN CO.  MANUAL PROGS BLENDED THE 00Z ECMWF/GFS/NAM/SREFMEAN.

TERRY/PETERSEN

GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV

24HR QP VT 04/12Z
 0.01 486611 482602 476594 469595 458596 437618 410649 374686
      345714 319742 310756 309760 308766 307771 308777 310783
      313787 318789 322789 341774 352777 355775 359777 356782
      353786 350791 349797 349802 352807 355809 359815 358822
      355825 351830 349838 356843 359852 362855 367855 371857
      374862 380870 384875 389878 396879 400878 407879 412881
      419884 426885 431886 438884 444881 451879 456879 464885
      467888 470889 472886 475880 476872 473861 470855 466852
      462847 458829 456815 453806 448800 433792 416776 411774
      408775 404780 402784 397794 388796 385798 382797 378794
      375792 370787 367777 366769 369764 378764 388765 397764
      401764 408761 416752 419747 421742 424735 426730 433716
      437710 440706 447696 455686 464678 469673 475665 479661
      483653 486643 487631 487619 486611
 0.01 447019 446013 443008 439005 436003 433000 427997 424996
      418994 415995 413999 417002 420006 423009 427013 431016
      434019 437021 443023 447019
 0.01 409823 408820 407816 406813 405811 403810 401807 400806
      398808 397809 396813 397817 397818 399820 401823 402827
      403827 406829 408828 408825 409823
 0.25 476637 473630 468629 463629 457634 443643 437649 417673
      408685 400696 386718 380729 381736 385740 396744 400746
      402747 406746 409743 413739 415734 418729 420723 426710
      433698 443687 452676 461665 471653 475643 476637
 0.50 463650 461646 458647 453649 446652 440657 431668 423679
      414691 409702 409711 411714 416711 420705 429695 435689
      441683 448672 456661 463650

24HR QP VT 05/12Z
 0.01 457650 451643 448641 444642 439646 434649 430650 425654
      417660 414665 410671 407674 403679 398684 396686 392686
      384693 379695 375692 368689 363690 357696 352703 348711
      344720 339728 336736 336747 336758 336762 339765 344776
      347782 350785 353785 359783 366776 370768 372757 374747
      377737 381729 387721 389716 393712 402707 407707 410709
      417717 425720 434720 442716 447711 449707 452703 454696
      456690 458684 459678 459671 460667 460663 459656 457650
 0.01 520876 519867 517860 512850 507843 504840 497838 488837
      482840 480843 478848 477857 477861 478865 486875 493882
      500886 503888 509889 515886 519881 520876
 0.01 448746 447742 444741 440743 433748 426752 421751 417757
      419769 417776 412781 408784 406784 402782 399782 392785
      384790 379794 374800 362810 358816 353821 349828 348836
      350843 354850 358852 362853 366851 374849 381849 389846
      397841 407830 410824 411821 412818 411815 413808 417811
      421811 423809 426800 434786 437771 440763 445757 448750
      448746
 0.01 478866 467856 463857 459859 455861 450862 435862 423860
      416858 408860 405864 404866 405868 411874 417876 423877
      431875 440871 452872 463880 467882 471878 474872 478866
 0.01 449821 449817 447814 445814 442812 438811 436814 435815
      435820 436823 439826 443827 445826 448824 449821
 0.01 416255 418247 418241 416236 413235 408231 402228 395226
      392221 391213 391208 389202 382190 376188 372189 370193
      367197 361197 355194 353190 350187 347186 344185 339188
      336191 335197 334211 334218 335224 338229 341233 361247
      370256 374258 378255 382251 389252 396255 401258 409265
      411265 413261 416255
 0.25 366723 362721 359721 355725 354730 352735 350739 350744
      355745 358744 362741 365736 366732 366727 366723
 0.25 373231 370226 366219 364214 359209 353208 349210 347213
      346220 348225 356229 360231 365232 370233 373231

24HR QP VT 06/12Z
 0.01 494845 491837 487834 483833 482831 482822 480813 477807
      472805 465804 460804 455805 448805 441808 440814 441818
      445823 449831 451838 455845 460851 464854 470855 482854
      486853 491851 494845
 0.01 493226 495223 495219 493214 486207 478208 472211 469215
      466220 465229 462230 459228 456226 454222 456213 459208
      462205 469201 473196 477187 483182 486177 488171 489166
      489162 487156 483153 478151 474150 471148 465144 456139
      450134 445132 440133 435138 433141 430147 427156 423166
      421175 420185 415185 412187 411190 411198 412207 407202
      404201 400197 390194 379185 375180 369172 369169 370166
      369163 366161 362160 359160 357163 355174 355178 351176
      345162 340155 335154 331156 325159 322162 319167 318175
      318183 321191 324196 335209 341215 343219 345223 338242
      335249 334252 337254 345255 354252 367248 372248 376250
      383256 389259 395260 403259 408261 417264 422265 425265
      429264 436264 444261 455256 461250 465247 468248 477254
      480253 483245 485236 480230 488229 492228 493226
 0.01 452739 449737 445737 441742 440747 438753 435757 434762
      433765 435768 438767 444763 446760 448756 451749 452744
      452739
 0.01 451122 452116 449109 447105 442099 437097 432098 427100
      419099 415099 413097 409087 409080 405074 399070 395068
      389068 384072 379078 375083 372091 372097 377103 380108
      381112 378115 374119 370120 366120 362118 361128 360133
      361137 366141 372140 379134 390129 397132 396136 393138
      389142 387147 389151 393157 398158 403158 411159 415159
      418157 421149 424142 429135 433131 439128 448125 451122
 0.25 452192 453188 454184 456181 454176 454175 453176 451177
      450179 449183 449188 449189 450192 452193 452192
 0.25 439247 441244 441241 438236 434235 429234 425233 421229
      416220 404209 397205 389199 377189 371184 368182 366181
      363181 363187 366195 371201 376209 376211 372211 364207
      358202 352195 349188 347180 345171 343168 342166 339166
      334171 332178 333186 335194 339202 344207 350213 356219
      361225 368229 380242 386247 395251 400253 404253 413252
      420252 428252 435250 439247
 0.25 414118 414114 412112 409112 406111 403112 400113 400114
      403117 405117 406117 408119 411119 414118
 0.50 412246 414241 414235 413227 410222 404224 400228 392229
      387227 382228 381230 382233 386240 391244 399248 406248
      412246
 0.50 393206 389203 386200 383197 379193 376190 371187 368185
      366186 366189 369193 372198 375201 377203 383206 388207
      393206
 0.50 350204 351200 350197 349193 347189 346182 345178 344172
      341170 338172 336177 336184 337187 338194 339198 342202
      345205 350204
 1.00 343185 343181 343178 342181 342185 342186 343185

$$