Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 301851
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
251 PM EDT THU JUL 30 2015


PRELIM DAY 1 QPF DISCUSSION
VALID JUL 31/0000 UTC THRU AUG 01/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...CALIFORNIA...

A PLUME OF ANOMALOUS MONSOON MOISTURE WAS PUSHING NORTH AND
WESTWARD INTO SOUTHERN CALIFORNIA. THE MORNING SOUNDING AT SAN
DIEGO MEASURED A PRECIPITABLE WATER VALUE OF 2.03 INCHES...WHICH
WAS JUST SHY OF THE DAILY RECORD. THE MORE AGGRESSIVE PW AND QPF
NUMBERS FROM THE GFS MAY END UP BEING MORE CORRECT THAN OTHER
MODELS. A CHANNEL OF ENHANCED MID LEVEL EASTERLY WINDS EXISTS AT
THE PERIPHERY OF THE SOUTHERN U.S. RIDGE...AND NEAR AN INVERTED
TROUGH MIGRATING UP THE COAST. THESE ENHANCED WIND FIELDS SHOULD
PROMOTE SOME ORGANIZATION TO THUNDERSTORM ACTIVITY TODAY.
CONDITIONS BECOME LESS FAVORABLE FOR ORGANIZED HEAVY RAIN ON
FRIDAY...BUT UNTIL THEN LOCALLY INTENSE DOWNPOURS ARE POSSIBLE.
THIS IS ESPECIALLY TRUE IN FAVORED HIGHER TERRAIN...BUT THE
EXPANSE OF MONSOONAL MOISTURE WILL PROMOTE AN UNUSUAL BREADTH OF
UNSTABLE AIR...AND SOME PROPAGATION INTO THE VALLEYS AND DESERTS
LOOKS PLAUSIBLE...EVEN IF NOT FULLY REFLECTED IN THE NUMERICAL
GUIDANCE. WPC USED A COMBINATION OF THE 00Z PARALLEL WRF-ARW AND
06Z CANADIAN GEM REGIONAL MODEL...ALONG WITH SOME INFLUENCE FROM
THE PREVIOUS FORECAST AND GFS/ECMWF.


...SOUTHWEST STATES AND SOUTHERN PLAINS...

EARLY MORNING CONVECTIVE DEBRIS HAD THINNED ACROSS AZ/NM TO ALLOW
STRONG HEATING. DOWNSTREAM A SMALL SCALE AND SLOW MOVING MCS IN
KS/OK HAD FRAGMENTED BY MIDDAY...BUT CONVECTION HAD NOT ENTIRELY
DISSIPATED. A WEAK EXTENSION OF A NORTHERN STREAM MID LEVEL TROUGH
WAS BRUSHING ACROSS THE CAPE AXIS LOCATED IN OKLAHOMA AND WESTERN
ARKANSAS...COINCIDENT WITH THE DEEPER MOISTURE LOCATED NORTH OF A
SURFACE FRONT. DEVELOPMENT OF AN INVERTED SURFACE TROUGH IN
OKLAHOMA...AND WEAK WAVE ALONG/NORTH OF THE FRONTAL
BOUNDARY...SHOULD FOCUS ASCENT AND ORGANIZE CONVECTION THIS
AFTERNOON OVER CENTRAL/EASTERN OK. A ZONE OF RICH DEEP LAYER
MOISTURE STRETCHES FROM HERE WEST INTO THE PANHANDLES AND THE
NORTHERN HALF OF NEW MEXICO. WITH TIME SOME WEAK WARM ADVECTION
WILL CARRY MOISTURE/INSTABILITY INTO SOUTHERN COLORADO AS
WELL...WITH THE APPROACH OF ANOTHER WEAKLY PERCEPTIBLE MID LEVEL
WAVE THAT WAS ANALYZED ENTERING WESTERN COLORADO THIS MORNING.
AFTERNOON/EVENING THUNDERSTORMS IN THE MOUNTAINOUS TERRAIN MAY BE
SLOW TO ORGANIZE...BUT THERE IS A STRONG AND CONSISTENT MODEL
SIGNAL FOR ANOTHER MCS TO TAKE SHAPE OVERNIGHT IN NORTHEAST NEW
MEXICO. THE COLORADO SHORTWAVE MAY HELP TO REINFORCE AN EXISTING
SHEAR AXIS...WITH THE MODELS DEPICTING A SMALL 700 MB CIRCULATION
FORMING...AND ENHANCING SOUTHERLY FLOW INTO THE PRESUMED MCS. THE
MODEL FORECASTS FOCUS HEAVY RAINFALL MAINLY TO THE NORTH OF THE
AREA WHICH RECEIVED HEAVY RAIN THE PREVIOUS NIGHT. THIS MAY HELP
TO PREVENT HIGHER END FLASH FLOODING...BUT A RISK OF FLASH
FLOODING DOES EXIST...ESPECIALLY AS STORM MOTIONS WILL REMAIN VERY
SLOW. WPC BLENDED REMAINED CLOSE TO A MODEL CONSENSUS WHILE
STAYING AWAY FROM THE SREF...WHOSE QPF WAS TIED TOO CLOSELY TO THE
TERRAIN.


...SOUTHERN AND EASTERN U.S...

AT 18Z A SQUALL LINE WAS ALREADY WELL UNDERWAY IN THE MID
ATLANTIC. THE MODEL AND MANUAL QPFS HAD NOT CHANGED MUCH BETWEEN
CYCLES. MODERATE TO RAPID PROGRESSION WILL HOLD DOWN AREAL AVERAGE
RAINFALL TO MAINLY 0.25 TO 1.00 INCHES FROM THE MID ATLANTIC TO
NEW ENGLAND. VERY RICH MOISTURE COULD LEAD TO ISOLATED 1-2 INCH
TOTALS WHEREVER CELL MERGERS OR WET MICROBURSTS OCCUR. IN THE GULF
COAST STATES HEIGHTS WILL TAKE A SLIGHT DIP OVER THE OPEN WATERS
OF THE CENTRAL GULF AS ENERGY SPILLS INTO THE BASE OF A WEAKLY
DEFINED AND POSITIVELY TILTED TROUGH AXIS. WITH DEEPER NORTHERLY
FLOW DEVELOPING OVER THE GULF COAST STATES...A 925 MB MOISTURE
GRADIENT WILL SINK SOUTHWARD...SETTING A BACK EDGE TO MEANINGFUL
AMOUNTS OF PRECIPITATION. AMOUNTS WILL BE MAXIMIZED OFFSHORE...BUT
DOWNPOURS ALONG THE IMMEDIATE COAST FROM LOUISIANA TO THE WESTERN
FLORIDA PENINSULA SHOULD PRODUCE FAIRLY GENEROUS AREAL AVERAGE
AMOUNTS APPROACHING 0.50 TO 1.00 INCHES THROUGH FRIDAY. THE WPC
FORECAST MAINTAINED A LARGE PERCENTAGE OF CONTINUITY AND TRIED TO
CAPTURE TRENDS IN THE MODEL CONSENSUS...ESPECIALLY THE ENSEMBLE
MEANS.

BURKE

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

24HR QP VT 01/00Z
 0.01 539000 539995 538989 535977 533968 530960 520941 517934
      514923 509912 505902 500891 496884 492879 491869 491861
      489858 489853 487848 486840 483835 482829 472814 471807
      472801 473791 476770 477765 477758 478752 476748 473742
      469739 464739 462738 461734 459729 459724 464714 471706
      474702 480700 485697 490694 498689 504684 506679 506674
      506668 504663 500654 498649 495646 488642 483643 480638
      477636 468632 463632 456633 448630 443631 437633 432635
      428639 422646 412661 402676 393689 376720 371729 365739
      360750 357751 356749 354746 344762 338770 335771 337767
      341760 345751 346743 347735 346728 344726 340724 336725
      316731 305736 299738 295740 291742 287746 282753 272772
      269780 267791 253799 251803 251808 251816 250820 249826
      251835 256844 259853 260870 260877 258882 255892 252900
      247922 247936 247943 248948 255952 265952 276952 280948
      286943 288945 289950 282956 280960 281966 287975 290980
      291987 292999 294003 299006 305005 308002 310998 311992
      311977 310964 309955 309948 311945 314943 316939 318931
      317918 316914 315909 314902 314896 317888 321877 325872
      327867 331857 333852 332847 329843 331838 336830 336817
      341810 342806 344804 345806 344812 345815 347818 348817
      353809 356801 361794 368787 374782 381775 389766 402750
      427722 432716 438709 445703 451699 456698 457700 456702
      453705 450707 443715 443726 441728 441731 445732 454735
      455738 454740 451742 449741 447739 444739 442740 442743
      441747 445749 448748 450750 449753 444756 443762 446764
      453761 455776
 0.01 455776 458803 463829 462834 459837 458839 455839 454835
      450831 447831 443832 440829 436827 434830 435835 437837
      439842 438847 437843 436840 433840 429840 426838 421844
      422852 424853 425848 428843 432845 434847 432850 432852
      435851 438854 434857 440861 443863 447863 450864 450868
      450874 452879 455883 461891 463895 466895 470900 473902
      476907 475920 481937 484942 484937 485933 487933 488939
      489945 491947 494945 497947 503956 509963 513971 516980
      520992 524002 527007 532009 536004 539000
 0.01 460854 460852 459849 458847 456846 454845 453847 453848
      451850 450853 450855 450857 452860 453857 455855 456854
      458856 460854
 0.01 427994 428988 427983 427966 425954 420945 412926 407926
      407929 410942 410949 411954 406947 402946 398947 396949
      396953 396961 398972 401982 406990 409995 410003 407014
      406019 409019 412015 416013 421011 424008 427994
 0.01 413054 413050 412048 411045 408044 404046 402048 398048
      392045 387045 384039 384031 385020 382013 375998 371982
      370974 366967 360958 359956 356955 351952 346951 341953
      338960 337963 338965 340970 339975 337981 336986 335990
      331995 327001 327012 328014 328020 330026 333030 335034
      335038 340040 342041 343044 339044 337043 332044 325046
      324049 327056 330062 334068 328073 322076 320078 317081
      313085 310086 307085 304081 300077 294075 288074 281073
      274073 272075 271078 273084 278090 284095 289098 295102
      304111 305115 308117 310120 310124 309129 312133 317138
      320138 323134 322129 329118 332117 335119 341125 344132
      343135 341133 337128 336130 339137 339141 338143 336156
      334164 330161 325157 321157 320159 321165 327168 333171
      338176 341179 341182 343185 343189 348204 349208 353211
      358215 362219 366220 367216 360209 356205 356200 354195
      350192 349190 348185 350183 351187 354190 360189 368192
      373196 380201 390204 396205 392201 389200 387198 386193
      381189 379185 381183 374177 375179 373181 369179 364174
      361169 360169 358172 356169 354162 355152 356148 360149
      360156 360159 364160 370162 373166 375168 378169 382165
      381163 378162 374161 372163 366156 370153 369149 363152
      360149 359145 360140 358136 360134 362127 361123 361118
      360114 355110 355107 357105 361105 370113 373115 375114
      380110 381101 384093 384090 383085 385081 387077 390075
      395072 398071 400069 401062 406061 409054 413054
 0.01 386233 386232 385230 385229 383227 381226 380226 379226
      380227 380229 381230 382232 384233 386234 386233
 0.01 383117 383115 381115 379117 377119 375123 373125 373127
      373129 374132 376130 378130 379126 377123 379121 381119
      383117
 0.01 377105 375104 374103 373102 372101 371102 372103 373104
      373105 375106 377105 377105
 0.01 372095 372093 372091 371089 370091 370093 369095 371097
      372095
 0.01 347803 345800 345801 344803 345805 347803
 0.01 335776 333774 332775 330776 332778 334777 335776
 0.01 327786 324784 322787 315788 307789 302793 299792 296794
      297796 301801 305805 309805 316802 319798 321793 325788
      327786
 0.25 494671 494665 493658 492655 490654 486654 479654 473657
      467652 466647 462643 457645 450642 445646 447656 442660
      439664 437668 439670 443670 446670 447673 451674 458672
      462674 464677 467687 473694 477693 480691 486684 491677
      494671
 0.25 487904 487902 486899 486897 486894 485892 484889 483888
      481889 480891 480892 480893 481894 482896 483897 483898
      484899 485902 485904 485906 487905 487904
 0.25 422701 421696 417693 413682 407688 402697 397704 391711
      385719 380727 376735 373741 372747 372751 374755 371766
      371771 376769 379766 381761 387740 392733 398726 405728
      410725 414722 419714 422704 422701
 0.25 407977 408975 408973 408970 407968 407966 407965 407963
      406961 406959 405958 404956 403956 402959 402961 402963
      402966 403968 403970 404973 405975 407977 407977
 0.25 380194 379192 376190 375188 371186 370185 366183 363182
      360183 362184 366187 367187 371189 372190 376193 378194
      380194
 0.25 378053 376044 379034 379026 377023 372016 367010 364008
      364002 363989 361980 357973 356968 355964 352960 348961
      345971 347980 351988 355996 358005 355011 352013 348013
      345017 346022 348032 351039 352049 350055 348060 347062
      348065 349068 349073 346074 339072 336076 330076 328079
      329083 328086 330088 330090 333092 333098 334100 336100
      340100 343098 344087 345085 349086 354088 353092 355095
      358097 362095 365093 366090 362084 360078 363074 369069
      378053
 0.25 350165 350163 349162 347161 346161 345162 345164 346165
      346167 347167 348166 350165
 0.25 345109 345107 344107 343105 343104 342105 341106 341107
      341108 341109 342110 344110 345109
 0.25 333754 332748 330746 326745 321743 315744 308745 302747
      297749 292753 286762 283768 282773 282780 286781 290779
      293775 298771 311768 317767 323764 328762 332756 333754
 0.25 336802 337798 335796 332796 328800 326805 321816 318823
      318828 319836 316841 313839 311832 313830 313826 309824
      303826 299825 297823 296820 297816 295814 292809 290803
      286798 281796 275795 269795 265797 262802 258805 259807
      265806 268812 268815 266817 260819 259823 260829 264833
      268836 269839 268843 267850 267857 266870 265882 262898
      260903 257908 255913 254918 255926 257930 261933 267937
      272937 279935 283933 286930 293922 296916 299909 300903
      303899 307889 312879 316867 322855 320848 320841 324838
      326833 323825 326819 330815 331811 333808 336802
 0.25 332103 333101 332100 331099 330099 329097 327098 325100
      325101 324102 323103 322104 322106 322108 323108 324110
      326111 328109 329107 330106 331105 332104 332103
 0.25 317116 318114 316113 315112 314114 314115 316116 317116
 0.25 317108 318106 317104 316103 314104 312105 313107 315108
      317108 317108
 0.25 319095 318093 317095 318096 319095
 0.25 301987 301985 301983 299985 299987 301989 301987
 0.25 280848 280846 280844 279842 277841 275842 274844 274845
      273847 273849 274851 276851 278851 278850 280848 280848
 0.50 488668 488665 484666 483667 480670 478671 475674 474677
      474680 475682 478683 481680 483679 485676 487673 488670
      488668
 0.50 390730 390725 389722 387724 384726 382729 381732 380734
      379737 380740 384739 385737 387735 389732 390730
 0.50 375037 377032 376027 370021 367015 365012 361011 359012
      358016 354024 352031 352035 353040 355046 352055 353061
      354066 352074 352077 355076 357073 362070 364067 362063
      363062 364065 367065 368061 368059 368054 369046 375037
 0.50 360091 359090 357090 356091 356093 358092 360091
 0.50 354084 354082 352080 351081 352084 354084 354084
 0.50 340093 340091 340089 341089 340087 341085 341083 341082
      339081 338081 336082 334084 333086 333087 335088 336088
      336091 336093 336094 338094 340094 340093
 0.50 342076 342075 340074 339076 340077 341077 342076
 0.50 329753 329750 326747 321747 314748 307750 302753 300758
      300761 303763 308764 314762 319762 325760 328755 329753
 0.50 332079 333077 332077 331079 332080 332079
 0.50 327107 328105 327103 325104 324105 324106 324107 326108
      327107
 0.50 319855 315850 310850 301834 297829 294827 291826 280825
      272823 266821 263821 262825 265829 268831 275834 282836
      284838 286842 290846 292850 293854 291856 288859 285858
      278859 270864 268874 266890 264901 260908 258911 258914
      259919 261923 266929 275931 280929 282927 286920 288916
      288910 289900 289895 291892 294891 296891 300890 303888
      309880 312874 311868 309865 307860 307857 309859 312865
      313854 319855
 0.50 293818 288814 287813 288810 288806 285804 281802 277799
      270800 271804 273810 275816 279819 285822 290820 293818
 1.00 372032 372030 369028 366023 365020 363021 360027 358034
      356035 357040 358047 357051 359052 365051 365045 367040
      371035 372032
 1.00 361065 360065 359064 358065 358067 358068 360067 360066
      361065
 1.00 322754 322752 321751 320751 318752 316753 314753 313753
      313754 311756 313757 313758 315758 317758 319757 320757
      322756 322755 322754
 1.00 296838 296836 295835 294834 294832 293831 291831 289832
      289833 289835 290836 292837 293838 294839 295839 296838
 1.00 296874 296866 292868 287869 282873 280878 275882 272885
      270892 267905 265910 264915 266919 274925 277923 280916
      282904 285889 289878 296874
 1.50 369034 368030 366028 364027 363029 362032 360034 358037
      358039 360043 362045 363041 364038 366035 369034
 1.50 363050 363049 362047 360049 361050 363050 363050
 1.50 280900 280894 278890 276891 275896 273900 271903 270909
      269913 272916 275914 276908 278904 280900 280900

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