000
FXUS04 KWBC 172244
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
542 PM EST TUE FEB 17 2009


FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 18/0000 UTC THRU FEB 21/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...ERN STATES...
MDLS ARE IN REASONABLY CLOSE AGREEMENT IN THEIR HANDLING OF THE
SYS MOVG THRU THE CNTRL AND ERN STATES THIS PD..WITH THE SRN
BRANCH OF THE H5 TROF MOVG FM THE ROCKIES INTO THE OH AND TN VLY
BY THE END OF THE PD WHILE THE NRN STREAM H5 TROF DIGS INTO THE
UPR MS VLY BY WED EVE.  GUIDANCE SUPPORTS SIGNIFICANT
STRENGTHENING OF THE LLJ UP THRU THE GULF CST AND SERN STATES AHD
OF THE SRN STREAM H5 ENERGY..WITH WSWLY/SWLY LLJ INCREASING TO
GREATER THAN 50KTS..WHICH WL BRING IN PWS IN EXCESS OF 1 INCH.
THIS INCREASING LLJ/MSTR ADVECTION WL SUPPORT AN EXPANDING WAA
RNFL PATN FM THE LWR MS VLY EWD INTO THE CAROLINAS..WITH LRG SCALE
LIFT ALSO AIDED BY UPR JET DYNAMICS.  GENERALLY PREFERRED THE
12Z/ECMWF AND SREF MEAN QPF SOLNS..WITH WIDESPREAD 0.50-1.25 INCH
RNFL AMTS LIKELY FM NRN MS ENEWD INTO THE CAROLINAS....THOUGH 18Z
GFS AND NAM ARE FAIRLY SIMILAR.  LIGHTER WARM ADV PCPN WILL STREAM
INTO THE MID ATLC REGION ON WEDS WITH AMTS GENERALLY BETWEEN .10
AND .25...AS HEAVIER SRN STREAM QPF WILL REMAIN FROM SRN VA SWD.
FROM PTNS OF THE OH VLY INTO THE GTLKS..INITIAL WAA PATN AHD OF
THE SRN STREAM ENERGY FOLLOWED BY LRG SCALE LIFT FM THE AMPLIFYING
NRN STREAM H5 TROF WL PRODUCE WIDESPREAD PCPN/SNOWS ESP FM THE UPR
OH VLY INTO THE GTLKS..BUT WITH DEEPER MSTR BEING INTERCEPTED BY
SRN BRANCH SYS..XPC WTR EQUIVALENTS TO BE MSTLY ON THE LGT SIDE
HERE..GENLY BTWN 0.25-0.50 INCHES.  MDL QPFS WERE FAIRLY SIMILAR
HERE AND RATHER CLOSELY FOLLOWED.

...WRN STATES...
WEST COAST H5 ENERGY IS FCST SIMILARLY BY ALL MDLS TO SHEAR EWD
THRU THE GT BASIN AND ROCKIES DURG THE PD..WITH RDG TEMPORARILY
BLDG IN OVR THE IMMEDIATE W CST BHND THE S/WV.  THERE WILL NOT BE
MUCH PAC MSTR LEFT WITH THIS SHEARING OUT SYS..BUT ENUF LIFT AND
SOME WK UPSLOPE COMPONENT SHLD STILL BE ENUF TO TRIGGER MSTLY LGT
PCPN TOTALS..ESP FM WRN WY SWD INTO NRN UT AND PTNS OF SCNTRL WY
INTO NRN CO.  ALSO..SOME RESIDUAL ENHANCED PCPN IS LIKELY THRU THE
SIERRA RANGE EARLY TONIGHT BEFORE THE SYSTEM REALLY BEGINS
SHEARING OUT.  GFS AND NAM QPFS QUITE SIMILAR THRUOUT THE WRN
STATES AND WERE FOLLOWED WITH ADJUSTMENTS FOR LOCALIZED OROGRAPHIC
ENHANCEMENT.


DAY 2...

...EAST...

THE CLOSED DEEP LAYER CIRCULATION MOVING EAST FROM THE GREAT LAKES
ON DAY 2 IS EXPECTED TO BRING WIDESPREAD PCPN TO NEW ENGLAND AND
THE SOUTHEAST.  LOW PRESSURE AT THE SFC WILL REDEVELOP IN EASTERN
NEW ENGLAND...COMBINING WITH AN 850 MB JET OF 50 KT MOVING ONSHORE
TO SUPPORT A LOW LEVEL CONVERGENCE MAXIMA IN NH/ME AND HIGHER QPF
AMOUNTS.  TIMING DIFFERENCES LEAD TO QPF DIFFERENCES...AS THE 12Z
NAM SLOWED DOWN THE FORWARD PROGRESS OF THE
CIRCULATION...RESULTING IN HIGHER QPF AMOUNTS.  MANUAL PROGS
BLENDED CONTINUITY WITH THE 12Z GFS/CANADIAN/UKMET/ECMWF...AND
GAVE LESS WEIGHT TO THE NAM/00Z ECMWF.

A SECOND AREA OF CONVECTIVE PCPN IS EXPECTED OVER THE SOUTHEAST
U.S. IN ASSOCIATION WITH A COLD FRONT PROGRESSING ACROSS THE
REGION.  MOISTURE STREAMING NORTHEAST IN ADVANCE OF THE FRONT WITH
PW VALUES TO ONE AND A HALF INCHES ALONG THE FL GULF COAST
SUPPORTS SHOWER AND THUNDERSTORM DEVELOPMENT ALONG THE FRONT AND
LOW LEVEL JET MAXIMUM FROM SOUTHEAST AL/FL PANHANDLE/GEORGIA. PCPN
SHOULD BECOME INCREASINGLY LESS ORGANIZED FROM THE END OF DAY TWO
INTO DAY THREE AS THE LOW LEVEL FLOW BECOMES MORE PARALLEL TO THE
SFC BOUNDARY AND HIGHEST PW VALUES AND HIGHEST SFC-500 MB RH MOVE
OFFSHORE.  MANUAL PROGS BLENDED THE GFS/ECMWF/CANADIAN
GLOBAL/UKMET QPF.


DAY 3....

NORTHERN NY/NORTHERN NEW ENGLAND...

THE MID LEVEL CYCLONIC CIRCULATION DRIFTS NORTHEAST NEAR NORTHERN
NEW ENGLAND...WITH MOISTURE CONTINUING TO WRAP AROUND THE
CIRCULATION INTO THE REGION. WHERE NORTHWEST TO WEST FLOW TURNS
UPSLOPE SHOULD PROVIDE ACCUMULATING SNOW SHOWERS ACRS THE
MOUNTAINS FROM NORTHERN NEW YORK AND ACROSS VT/NH/WESTERN ME.  A
SECONDARY MAXIMA IS EXPECTED OVER THE TUG HILL WHERE FLOW TURNS
UPSLOPE AFTER MOVING ONSHORE FROM LK ONTARIO. MANUAL PROGS GAVE
MORE WEIGHTING TO THE HIGHER RESOLUTION NAM...SUPPLEMENTED BY GFS
RELATIVE HUMIDITY AND CONVERGENCE PROFILES.

NORTHERN PLAINS/UPPER MS VALLEY...
LIGHT SNOW IS EXPECTED TO BREAK OUT OVER THE NORTHERN PLAINS TO
UPPER MS VALLEY AS THE NEXT LOW-MID LEVEL SHRTWV MOVES DOWNSTREAM
FROM THE CANADIAN PRAIRIES SOUTHEAST ACROSS THE BORDER INTO THE
REGION.  AVAILABLE PRECIPITABLE WATER VALUES WILL BE QUITE LOW
UNDER A QUARTER INCH. FORECAST VERTICAL MOTIONS ARE TEPID AS
WELL....SO AMOUNTS WILL BE LIGHT.
A GFS/UKMET/ECMWF MODEL BLEND WAS USED HERE.  LIGHT SNOW WILL
EXTEND INTO PORTIONS OF THE BIGHORNS AND BLACK HILLS WHERE THE
BNDRY LAYER FLOW TURNS UPSLOPE.

HEDGE/PETERSEN

GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV
24HR QP VT 19/00Z
 0.01 511802 508791 506782 499769 492762 485757 478752 471747
      455740 446735 438730 434726 430720 423712 417706 411705
      402707 396709 390711 370720 348731 343734 338738 333745
      325761 320770 317780 309796 307805 306812 304822 306833
      304845 301855 300875 296892 294903 293910 290922 288933
      287943 287954 289959 295960 298961 303960 306959 310961
      315962 334952 352943 356941 362938 367932 370924 375916
      384910 388909 394911 399919 403930 421970 424975 430974
      433971 437965 443954 449948 454945 459946 464949 467953
      468957 473959 478958 482956 488952 491947 493942 494932
      497905 501881 503867 504859 504854 505844 503837 504827
      507823 510816 510811 511802
 0.01 489139 487134 484130 478126 470124 466123 459119 458118
      462114 467115 472111 472105 470099 469096 468094 466096
      461099 460096 459091 459083 459077 458072 456068 453065
      448062 437055 432043 426033 423029 420029 417033 413039
      409045 405048 401050 389056 384061 381060 376056 369055
      364059 360064 360067 361069 364074 372085 377089 379094
      385095 389093 392090 394093 398093 394123 399126 403128
      407129 415127 423130 429128 433124 438123 440124 441129
      439137 436139 433142 431150 433156 436162 440165 444171
      450175 454174 454168 457161 461161 464163 471166 474167
      477165 479164 481159 480154 476151 473145 479142 484141
      489139
 0.01 416224 417220 417216 413212 409210 406206 390195 381190
      373187 371185 368184 362185 364192 374206 377208 377211
      375214 367210 364206 359203 354203 351204 350207 351209
      353213 358220 362224 366226 371228 376231 384236 395240
      400239 404236 408235 411232 416224
 0.01 422174 423170 423166 423165 421162 420158 420157 418154
      418153 415153 414157 415161 416165 417167 417169 418173
      419174 422174 422174
 0.01 427100 427099 424096 424094 422092 422088 424084 424080
      421080 418080 415083 414084 415087 415091 415095 413099
      415102 418102 421099 424097 426100 427100 427100
 0.01 399170 400162 398159 397154 395149 392146 385143 381140
      376130 371125 368123 365124 362128 361135 370142 372149
      376148 379146 383146 386149 393153 394158 396163 394168
      392172 396173 399170
 0.25 487830 484821 482818 475810 468805 461802 455800 448796
      435785 428780 421776 412774 408777 404780 398786 394792
      388799 385799 382796 379789 379786 380781 381777 380773
      376770 373768 366766 370763 374761 377756 378753 376747
      369747 360749 354750 349754 338768 334776 332783 330791
      330798 329809 328818 327823 325827 320833 317840 316847
      314855 313864 311875 309882 305900 304908 303916 305927
      308928 310926 312922 316914 321908 324908 325915 327926
      331930 336926 348914 352907 357899 363882 370868 375860
      378857 380855 383856 387859 389863 391870 393874 399883
      404890 413907 417908 419908 425906 432903 435903 443907
      447909 452907 454904 457900 461892 464889 467886 472883
      475880 479870 482859 484849 487837 487830
 0.25 448113 448109 447105 446105 444102 441101 438101 435103
      434104 432106 431108 430112 431116 432116 435114 438114
      441115 443115 446116 448113
 0.25 420064 418063 415062 412062 410062 407062 404063 401064
      401065 399068 398072 401075 402076 404076 407076 410076
      412076 413076 415073 416072 417068 418066 420064
 0.25 405217 405215 404213 402211 400208 399208 397206 395204
      392203 389202 386202 384204 386206 388208 390209 391210
      393212 396214 397215 399217 401218 404218 405217
 0.50 400212 399211 397211 394207 396211 397211 399212 400212
 0.50 368829 367824 365820 361818 357813 357804 357798 356790
      355788 350783 348782 344782 341787 339792 338798 338811
      336823 333836 332841 329845 325850 323855 320865 318872
      318880 319884 321885 324884 328886 332892 334897 336905
      339906 342905 346901 349897 352891 356879 360869 363862
      364856 366845 368829

24HR QP VT 20/00Z
 0.01 506677 498657 491644 484630 476619 473615 467610 460607
      455607 449607 444608 439611 427619 416628 407636 395647
      365685 346704 332720 318736 314741 312746 307756 303766
      299775 296783 290792 289794 286795 282795 277797 275799
      268808 265813 264818 264829 265832 264836 263841 266846
      272857 271864 270868 268879 270903 271910 272914 275916
      281924 285927 288929 292930 298929 306922 313914 325900
      331889 337881 348865 360846 363842 368840 370840 372842
      375845 377849 379851 381852 385850 386845 389845 393846
      396848 402861 406866 412869 420875 436882 448886 458889
      461890 465896 469896 473891 476887 478881 481865 484851
      487839 491823 491816 493808 497797 502783 510758 513743
      515734 514729 515722 514713 512701 506677
 0.01 487139 486135 485134 483133 480133 478132 476133 475134
      473137 474138 477138 480139 483139 486139 487139
 0.01 455122 456116 456110 456100 454096 450094 441093 437093
      434092 431090 427089 427096 429100 427104 423105 422109
      423112 429117 433119 438117 443117 448121 455122 455122
 0.01 450076 447073 447072 444069 441068 439069 436070 434072
      435076 436076 439077 439076 441075 444075 446076 447080
      450076
 0.01 417068 418064 415060 412057 409054 404053 398056 395058
      392061 388065 387069 385072 386076 389079 392081 395079
      401079 407079 410076 413076 415072 417068
 0.25 485681 482671 478662 472652 465644 456636 451634 447632
      444632 439636 428645 424650 422655 419658 416659 411659
      407660 402663 392671 385678 375686 369691 364696 357703
      351711 339728 329744 320762 312779 302797 293812 289819
      286829 284838 285843 287847 291851 293857 295864 295867
      293872 292878 291881 292888 296892 300894 304896 307895
      309892 317877 323868 328861 332853 335842 342826 346817
      349808 354795 357785 362767 365758 370748 377740 384736
      389737 394739 402742 409745 413747 417754 418762 418765
      417773 414779 410786 405791 400794 396794 393796 389801
      386805 391807 396807 399809 402813 406816 425820 434818
      440817 445814 451809 455803 457799 462794 471786 476776
      478764 480749 483725 483712 485702 486696 485689 485681
 0.25 455857 456853 456849 453844 448848 445850 440855 437857
      432859 428859 423862 425865 427866 430867 437869 440869
      445868 451865 453862 455857
 0.50 475674 472669 469664 461656 454650 450650 446655 439664
      430672 427683 424692 422702 421707 423711 424715 421725
      420729 422734 425737 431744 431749 434755 438758 442756
      447754 449750 452738 453733 455729 457727 460724 463718
      466706 467700 470696 475685 475674
 0.50 396681 384687 375692 367699 359708 352719 348727 343737
      339746 330766 323784 318794 315804 311813 304820 299824
      296828 295832 294837 296843 301843 303842 304845 302851
      300861 300865 301871 305873 310872 315867 321857 325849
      334829 342786 343775 347764 352756 359747 373730 380720
      386710 391703 393696 393688 396681


24HR QP VT 21/00Z
 0.01 498648 495638 491629 488625 485624 480627 456640 451641
      446640 442639 440640 436642 433646 431653 430660 431677
      422732 419745 414759 413766 410772 401782 397787 390790
      382795 378799 374804 371808 368810 361813 358816 354821
      354825 358832 363832 371829 378825 385818 388812 394807
      398806 403806 406810 408820 412826 414827 418825 426822
      437823 443821 451817 457813 461809 466803 470797 479787
      485779 489772 494759 498741 502710 502702 503693 502675
      498648
 0.01 505013 504000 503990 499981 493974 490970 483966 471957
      467953 464949 461947 455943 451938 447932 443921 439914
      435908 425902 416901 413904 411910 411917 414925 416936
      419947 421954 424958 425962 433976 437982 441990 445995
      449002 452009 456018 464034 467040 469043 473045 479047
      488047 492048 495046 499037 504017 505013
 0.01 451859 449855 443857 438859 432860 426861 423862 418864
      419868 422870 425870 431870 437869 440869 445867 450864
      451859
 0.01 465068 467059 467051 464045 461043 453039 450038 448035
      446031 443027 441025 438025 434028 432036 433052 435060
      434068 439076 445084 449089 453091 456088 459080 464072
      465068
 0.01 409245 411242 411238 410237 408234 405234 402235 400235
      398236 396238 395241 397244 400246 402247 405247 409246
      409245
 0.01 290775 284777 277780 271783 268786 262794 257806 256816
      256828 256831 259832 262831 268822 272813 275802 275797
      277791 280787 284783 289779 290775
 0.25 476684 472677 470674 467673 464675 460680 454690 448700
      441709 435719 437724 435728 438731 442732 446732 450727
      455719 461710 467700 474690 476684
 0.25 439757 438753 437751 435755 434755 433760 436763 437763
      438762 439759 439757

$$