Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 300655
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 AM EDT SAT AUG 30 2014


PRELIM DAY 1 QPF DISCUSSION
VALID AUG 30/1200 UTC THRU AUG 31/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

UPPER MS VALLEY INTO THE UPPER LAKES

PW VALUES FORECAST TO REMAIN ABOVE AVERAGE---1.5 TO 2+ STANDARD
DEVIATIONS ABOVE THE MEAN---FROM THE UPPER MS VALLEY INTO THE
UPPER LAKES DAY 1.  CONVECTION LIKELY TO REMAIN ACTIVE IN THIS
HIGH PW AXIS AS AN UPPER TROF AND ASSOCIATED MID LEVEL CIRCULATION
CENTER LIFT OUT OF THE UPPER MS VALLEY AND EVENTUALLY CROSSES THE
GREAT LAKES REGION LATER TODAY OR TONIGHT.  IT APPEARS THAT THE
PCPN AMOUNTS WILL BE DECREASING WITH TIME DURING THE PERIOD AS THE
VORT LIFTS OUT.  THERE IS THE USUAL AMOUNT OF LATITUDINAL
DIFFERENCES WITH THE QPF AXIS---WITH THE IN HOUSE PSEUDO BIAS
CORRECTED MEAN USED FOR THE AXIS.
WESTERN GULF COAST INTO THE LOWER MS VALLEY

TWO LOW/MID LEVEL CIRCULATIONS CONTINUE TO BE THE FOCUS FOR
CONVECTION...ONE ALONG THE GULF COAST WHICH EVENTUALLY LIFT NORTH
INTO THE LOWER MS VALLEY AND A SECOND CENTER ALONG THE WESTERN
GULF COAST WHICH MOVES LITTLE.  WITH THE AIRMASS ACROSS THE REGION
REMAINING QUITE MOIST...SOME 1.5 TO 2+ STANDARD DEVIATIONS ABOVE
THE MEAN...HEAVY PCPN WILL PERSIST THROUGH THE DAY.  THE HIGHEST
CHANCES FOR EXCESSIVE RAINFALL LOOK TO BE OVER SOUTHWEST LA OR
EXTREME SOUTHEAST TX AS THE CIRCULATION CENTER JUST SOUTH OF THE
COAST FEEDS MOISTURE INTO THE AREA AND EVENTUALLY BEGINS TO LIFT
NORTH OVER THE SAME REGION LATER TODAY OR TONIGHT.  HOW QUICKLY
THAT PICK UP OCCURS BY THE SYNOPIC SCALE FORCING WILL IMPACT HOW
MUCH RAFL FALLS.  ACROSS FAR SOUTH TX...MODELS AND ENSEMBLES HAVE
BEEN SUGGESTING THAT MUCH OF THE RAFL WILL BE OFFSHORE.  AS
MENTIONED EARLIER...THE MODELS HAVE NOT DEPICTED THE LOW VERY WELL
SO WPC QPF AMOUNTS WERE INCREASED ABOVE MODEL GUIDANCE VALUES.

THE SSEO WAS HANDLING THE PLACEMENT AND PCPN AMOUNTS FAIRLY WELL
FRI EVE AND WAS GIVEN MORE WEIGHTING THE NAM CONEST OR ARW THROUGH
THE AFTN.  BY THIS EVENING REVERTED BACK TO A SOLN BASED MORE ON
THE ECMWF AND PSEUDO BIAS CORRECTED QPF AS SYNOPTIC SCALE FORCING
BECOMES MORE IMPORTANT.

LOWER TO MIDDLE MS VALLEY/LOWER OH VALLEY

IN BETWEEN THE EXPECTED PRECIPITATION MAXIMUM OVER THE UPPER MS
VALLEY/UPPER LAKES AND THE MAX OVER THE LOWER MS VALLEY/WESTERN
GULF COAST REGION---MODEL CONSENSUS IS FOR LIGHTER TOTALS FROM
PORTIONS OF THE LOWER TO MID MS VALLEY/LOWER OH VALLEY.  DAY 1 QPF
DID NOT DEVIATE FROM THIS DEPICTION---ALTHOUGH WITH ABUNDANT
MOISTURE ALSO FORECAST TO REMAIN ACROSS THESE REGIONS---HEAVIER
PRECIPITATION TOTALS ARE STILL POSSIBLE.

NORTHERN ROCKIES INTO THE NORTHERN PLAINS

HEIGHT FALLS MOVING ACROSS SOUTHERN CANADA WILL BRUSH THE NORTHERN
ROCKIES AND NORTHERN PLAINS...HELPING TO PUSH A SFC COLD FRONT AS
FAR EAST EAST THE CENTRAL DAKOTAS BY SUNDAY MORNING.  A NARROW
BAND OF ABOVE AVERAGE PW VALUES ALONG AND AHEAD OF THE FRONT WILL
SUPPORT SCATTERED CONVECTIVE POTENTIAL FROM THE NORTHERN ROCKIES
INTO THE NORTHERN PLAINS.  THE MODEL CONSENSUS IS FOR LIGHT TO
MODERATE AMOUNTS AHEAD OF THIS FAST MOVING FRONT.  THE DAY 1 QPF
DID NOT DEVIATE FROM THIS IDEA.

BANN

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

24HR QP VT 31/12Z
 0.01 564991 564984 562979 559976 555974 547972 536972 526972
      517972 512971 509969 503965 491953 485946 481944 476943
      466943 457945 443952 431964 429968 432972 436975 439976
      445976 449974 454975 457977 463982 465984 465989 451998
      444005 441009 440013 443023 444029 443033 442039 438041
      433037 417031 405045 400046 396048 391048 394053 397055
      402056 410053 415053 418055 421056 423058 419062 411065
      408087 406098 405103 407107 412115 413118 416120 420119
      423116 426111 429114 432117 436118 439124 438131 439141
      442149 444155 447158 452154 468158 472151 478145 480140
      481135 477127 477118 479112 483105 494088 499081 502077
      504073 506069 510066 516062 530056 537050 540046 542042
      543036 543030 541024 541021 543020 550018 556013 557005
      559999 564991
 0.01 522266 519261 518257 517244 514225 522225 526225 529221
      534216 537213 539208 540205 539200 538194 536190 527174
      521168 515162 509157 506154 501154 498157 497163 496169
      496174 496195 495202 493207 488207 483206 476208 470210
      464216 466220 469223 472221 475222 480222 482222 484224
      485230 488232 487236 483237 480232 477230 471231 467232
      465236 464244 465247 477259 483265 490273 495278 502283
      507284 511282 514279 518277
 0.01 522144 522138 521133 516129 510123 506117 501113 498114
      497118 497123 500126 504130 509136 511144 514148 518149
      522144
 0.01 510658 510652 507648 503644 501642 498643 493645 487651
      484658 478671 470683 459690 453693 448698 446700 445703
      442710 442720 442729 440735 439740 437741 434746 433750
      432759 430765 426772 423777 419781 411788 398795 392798
      387803 377813 370822 363822 356819 349818 344816 337815
      332817 327820 323821 320820 310815 299812 286807 274804
      271803 267804 261808 258809 257814 257820 257828 260832
      270841 282845 292850 296852 298855 300862 302869 301876
      290885 282895 273904 266914 259924 254935 251941 249949
      248957 243959 239959 237962 233967 232972 237976 239979
      243979 252979 260988 265990 268991 271990 279981 323954
      331954 339954 351949 365946 376943 390920 398908 408898
      416899 421901 426904 425912 426922 427924 432924 443919
      450916 455913 464905 472893 480880 486866 492853 497839
      499834 501826 503818 505809 507792 508773 510752 512742
      511731 508712 510679 510658
 0.01 456221 455220 454220 452219 451220 450221 448220 447220
      445220 444220 444223 446224 448225 449225 450224 451224
      453224 454223 455222 456221
 0.01 436083 435081 434080 432079 431080 430080 429082 430084
      432085 433087 435085 436083
 0.01 426098 426096 427094 427091 427089 427087 428084 427083
      426084 425086 425087 424089 423091 424093 424096 424098
      425100 426098
 0.01 409021 408017 404016 400018 398021 395023 389024 389029
      393030 398030 400028 404026 407024 409021
 0.01 396004 396002 394000 392000 389002 387004 385006 383006
      379008 378010 378011 379013 383013 385011 387011 390009
      392007 394007 396004
 0.01 329801 327796 323796 319799 318802 314805 311807 309809
      312814 317813 321812 324810 327805 329803 329801
 0.01 283101 284096 284091 283086 270079 260070 250060 239053
      230052 227054 227058 228062 231064 238066 243071 248076
      257086 262091 266097 272101 275103 279103 283101
 0.25 550998 549990 546984 541982 536981 531982 530986 527992
      524993 523991 524989 521987 515986 511986 510988 511991
      517993 522994 523997 522999 521005 523009 525010 529010
      540007 545006 548004 549001 550998
 0.25 531205 530199 529194 527188 524184 521181 518179 514181
      514187 515190 517196 519201 522204 526206 531205
 0.25 514264 513258 510252 508244 505239 501233 499228 496226
      496234 499240 501244 504250 505258 509263 514264
 0.25 514019 514014 510014 503016 489020 480021 476019 475016
      475006 473002 470000 463004 459010 453030 452036 453043
      455045 460045 468044 473044 476046 479049 483051 490050
      503044 510039 512034 511027 514019
 0.25 502708 499691 496686 492683 487686 483690 477699 470709
      462716 459719 456725 454735 445758 437782 436788 433793
      429794 425796 417806 414809 409811 404815 400818 393826
      388827 383827 379830 375834 373838 368841 362843 358843
      352843 348844 345844 341847 336852 334856 331860 329865
      326877 323882 319885 314886 309885 304888 300891 286904
      279912 274919 268929 263939 259950 255959 253964 252971
      254976 257979 261983 265984 268981 273979 281973 289966
      296959 305953 321943 339934 345933 352933 364936 369933
      372929 378920 389902 394892 397888 401885 407877 413866
      418855 423855 427857 431859 435862 440871 441880 442889
      443894 446899 449900 451899 455894 460884 470863 476855
      481845 486834 489822 496794 499782 499776 499768 500751
      500737 502708
 0.25 501980 500975 497972 489968 481964 476959 467955 464958
      463961 463964 466968 471969 476975 480984 482987 487989
      492989 495987 499984 501980
 0.25 463112 464106 462103 459096 459090 458084 458075 458067
      457063 455059 451058 447067 444072 445081 447087 440098
      438101 438106 441113 447125 451129 456126 462113 463112
 0.25 451818 447818 444819 436823 428829 424832 423834 417842
      416846 418850 421851 423848 430841 435835 441829 449824
      451818
 0.25 413838 409836 406838 401843 397850 394858 393867 393870
      395873 397874 398871 401863 404857 408849 411842 413838
 0.25 288822 285821 283820 279819 277819 275818 272816 268818
      270822 272824 274826 276827 278828 282829 285828 287825
      288822
 0.50 539000 539998 539997 537996 536995 534995 532996 531997
      529999 528000 528002 529004 531005 532005 534004 535003
      536003 537002 539001 539000
 0.50 523197 524195 524192 523191 522190 521191 521194 521196
      522197 522198 523197
 0.50 497711 497704 495700 492696 489695 485697 482700 479706
      474713 468719 466722 465727 464732 461735 456742 453751
      454757 457758 460759 462762 462765 462779 462784 460789
      458797 460805 461810 460816 456824 451830 448838 447843
      448847 450852 449856 449863 450868 452873 454876 457874
      460870 464862 472848 476840 479831 483823 485814 489792
      491782 493772 494762 495750 494737 495725 497711
 0.50 491035 489034 487033 486032 484033 482034 482035 481037
      482039 484040 485040 486040 487040 489039 490038 491035
 0.50 471033 472031 471029 469027 471021 472014 470008 466008
      465011 463016 459023 457027 455035 457040 462040 467036
      471033
 0.50 457111 458105 456100 454095 452095 448097 444101 442105
      442109 445111 450114 453116 456113 457111
 0.50 388865 387850 386842 382841 375846 369853 364856 360857
      355857 351858 347860 343863 337871 332878 327887 322896
      320899 315903 306903 297907 290912 283918 277925 271933
      262949 258959 256965 255970 256974 259977 264979 268977
      277973 284966 289960 296953 303947 312942 319938 328934
      346924 355919 360912 364903 370894 373885 376881 381878
      386871 388865
 1.00 492710 487709 484712 481718 479724 478732 478740 475754
      473761 473766 474770 477777 478785 481781 483774 485768
      486760 484740 483735 484730 487726 490721 492713 492710
 1.00 357896 357892 355889 354885 352886 348876 339884 331893
      328901 324906 320909 313912 300917 294920 290923 285928
      282933 279939 278947 275953 271958 263968 265970 269971
      275968 279964 282958 286953 291948 299941 323929 329927
      336925 341921 346917 353906 356901 357896
 1.50 345908 345904 342903 339906 333910 327911 317917 306920
      299922 294924 291929 290931 290935 290938 294938 299935
      310931 320926 325923 332922 336919 340915 345908
 2.00 307926 306926 305924 303924 301925 299925 297926 296926
      296928 295929 296929 297930 299930 301930 303929 305928
      306927 307926

$$




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