Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 250713
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
213 AM EST THU DEC 25 2014


PRELIM DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID DEC 25/1200 UTC THRU DEC 28/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR

DAY 1

GREAT BASIN---SOUTHWEST---CENTRAL ROCKIES INTO THE LEE OF THE
NORTHERN TO CENTRAL ROCKIES

STRONG HEIGHT FALLS MOVING SOUTHEASTWARD FROM THE PACIFIC
NORTHWEST INTO THE GREAT BASIN EARLY THIS MORNING WILL CONTINUE TO
AMPLIFY INTO A CLOSED LOW DAY 1 OVER THE GREAT BASIN.  WIDESPREAD
MODERATE PRECIPITATION TOTALS LIKELY AHEAD OF THESE AMPLIFYING
HEIGHT FALLS THROUGH EASTERN PORTIONS OF THE GREAT BASIN--ACROSS
THE SOUTHWEST---INTO THE CENTRAL ROCKIES AND EASTWARD INTO THE
CENTRAL TO NORTHERN HIGH PLAINS.  LATEST MODEL GUIDANCE IS IN GOOD
AGREEMENT WITH THE LARGE SCALE EVOLUTION OF THIS TROF AND THE
ASSOCIATED PRECIPITATION DISTRIBUTIONS ACROSS THESE AREAS.
HEAVIEST PRECIPITATION TOTALS LIKELY THROUGH THE WASATCH INTO THE
TETONS--ACROSS THE  CO ROCKIES AND EASTWARD INTO THE CENTRAL TO
NORTHERN HIGH PLAINS WHERE THE LARGE SCALE LIFT AHEAD OF THE
AMPLIFYING UPPER TROF WILL BE ACCENTUATED BY POST FRONTAL UPSLOPE
FLOW IN THE WAKE OF THE ARCTIC SINKING SOUTHWARD DAY 1 IN THE LEE
OF THE CENTRAL ROCKIES.   SEE THE LATEST QPFHSD FOR FURTHER WINTER
WEATHER DETAILS.

EAST COAST

THE FULL LATITUDE UPPER TROF MOVING OUT OF THE MS VALLEY AND INTO
THE EASTERN U.S. EARLY DAY 1 WILL PUSH THE ASSOCIATED FRONTAL
BOUNDARY OFF THE ENTIRE EASTERN U.S. SEABOARD EARLY DAY 1.
PRECIPITATION ALONG THE FRONTAL BOUNDARY MAY LINGER EARLY DAY 1
OVER EASTERN MAINE---WITH MODEL CONSENSUS OF MODERATE TOTALS IN
THE .25-.50" RANGE CHRISTMAS MORNING.

SOUTH FLORIDA INTO THE KEYS

FRONTAL PRECIPITATION ALSO POSSIBLE ACROSS FAR SOUTH FLORIDA DAY 1
WHERE PW VALUES WILL REMAIN WELL ABOVE NORMAL.  MODEL CONSENSUS IS
FOR LIGHT TO MODERATE TOTALS FOR SOUTH FLORIDA---WITH THE HI RES
NSSL WRF---ARW---NMMB AND NAM CONEST SHOWING POTENTIAL FOR HEAVY
TOTALS ALONG THE IMMEDIATE SOUTHEAST COAST AND INTO THE KEYS.


DAY 2...

...SOUTHERN AND CENTRAL ROCKIES/SOUTHERN AND CENTRAL
PLAINS/MISSISSIPPI VALLEY/MIDWEST...

A RELATIVELY LONGWAVE TROUGH WILL SHEAR INTO TWO LESS PRONOUNCED
SYSTEMS...ONE PORTION LIFTING NORTHEASTWARD TOWARD THE UPPER
MISSISSIPPI VALLEY AND THE OTHER REMAINING PORTION REINFORCED BY A
SHORTWAVE MOVING SOUTHWARD DOWN THE WESTERN SIDE OF THE MEAN
TROUGH.  IN GENERAL...THESE SYSTEMS ARE CHARACTERIZED BY A
SHEARING POSITIVELY TILTED APPEARANCE AND THE CORRESPONDING QPF
FORECAST IS WIDESPREAD BUT NOT PARTICULARLY IMPRESSIVE.  FROM
COLORADO ACROSS THE CENTRAL PLAINS TO THE MIDWEST...PRECIPITATION
VALUES WILL REMAIN GENERALLY BELOW .25 INCH. HIGHER AMOUNTS ARE
LIKELY OVER THE HIGH PEAKS OF CENTRAL AND SOUTHERN COLORADO.
INCREASING MOISTURE WITHIN SOUTHERLY FLOW FROM THE GULF OF MEXICO
LIFTED NEAR THE SLOW MOVING COLD FRONT CROSSING THE SOUTHERN
PLAINS STATES WILL PRODUCE AN AREA OF SHOWERS/RAIN WITH AMOUNTS
GENERALLY BETWEEN .25 AND .5 INCHES FROM NORTHEAST TEXAS ACROSS
EASTERN OKLAHOMA AND WESTERN ARKANSAS. SOME CONVECTIVE ENHANCEMENT
NEAR THE GULF COAST COULD ALSO RESULT IN AMOUNTS GREATER THAN .25
ALONG THE CENTRAL GULF COAST. FOLLOWED THE 12Z ECMWF/NAM IN
HELPING REFINE CONDITIONS RESPONSIBLE FOR QPF.


DAY 3...

...OHIO VALLEY/TENNESSEE VALLEY/MIDDLE AND LOWER MISSISSIPPI
VALLEY/GULF COAST...

THIS QPF EVENT IS A CONTINUATION OF THE ONE DESCRIBED FOR DAY 2.
THE NORTHERN PORTION OF THE TROUGH...A PROGRESSIVE BUT RELATIVELY
WEAK SHORT WAVE MOVING FAIRLY RAPIDLY EAST NORTHEASTWARD  FROM THE
MIDWEST TO NORTHERN NEW ENGLAND WILL BE ASSOCIATED WITH SURFACE
WAVE OF LOW PRESSURE AND A SLOWLY SUBSIDING COLD FRONT FROM NEW
ENGLAND TO THE OHIO VALLEY BY SUNDAY MORNING.  MOSTLY LIGHT SNOW
WILL FALL TO THE NORTH OF THE LOW PRESSURE SYSTEM FROM THE UPPER
MIDWEST ACROSS MOSTLY SOUTHEASTERN CANADA AND NORTHERN MAINE. HAVE
FOLLOWED THE 12Z ECMWF AND HAVE TAKEN INTO ACCOUNT THE SLOWER
SPEED AND GREATER MOISTURE OVER THE GREAT LAKES OF THE 00Z RUN.

MEANWHILE...INCREASING MOISTURE OFF THE GULF OF MEXICO WILL
CONTINUE TO BE IMPORTED FROM THE GULF NORTHWARD AS THE TROUGH OVER
THE SOUTHWEST US MOVES EASTWARD ON SATURDAY NIGHT INTO SUNDAY
REACHING TEXAS/OKLAHOMA BY EARLY SUNDAY.  LOW PRESSURE APPEARS
LIKELY TO DEVELOP OVER THE LOWER MISSISSIPPI VALLEY/LOUISIANA BY
SATURDAY NIGHT WITH ANOTHER BOUT OF INCREASING RAIN/CONVECTION
DEVELOPING ALONG THE CENTRAL GULF COAST ON SATURDAY/SATURDAY
EVENING.  AGAIN FOLLOWED MORE OF THE ECMWF/ECMWF MEAN FORECAST
WITH SOME RELATIVELY CONSISTENT FORECASTS BETWEEN THE 12Z AND 00Z
RUNS.  QPF AMOUNTS INCREASE DRAMATICALLY ACROSS THE CENTRAL GULF
COAST WHERE 2 TO 3 INCHES ARE EXPECTED.  AS A RESULT AND FLASH
FLOOD GUIDANCE VALUES NEAR 3 INCHES...HAVE ELECTED TO INCLUDE A
SLIGHT RISK OF EXCESSIVE RAINFALL OVER THAT REGION.

...PACIFIC NORTHWEST/NORTHERN ROCKIES...

A POTENT SHORTWAVE TROUGH WILL DIVE SOUTHEASTWARD OVER THE PACIFIC
NORTHWEST ON SATURDAY INTO EARLY SUNDAY WHILE A RIDGE OVER THE
EASTERN PACIFIC AMPLIFIES SIGNIFICANTLY. MUCH OF THE PACIFIC
NORTHWEST AND PORTIONS OF THE NORTHWESTERN ROCKIES WILL SEE
MODERATE AMOUNTS OF QPF WITH HEAVIEST AMOUNTS IN THE CASCADES AND
ACROSS THE BITTERROOTS.  AMOUNTS WILL GENERALLY BE IN THE .5 TO 1
INCH RANGE WITH GREATER AMOUNTS IN THE HIGHEST ELEVATIONS. SEE THE
HEAVY SNOW DISCUSSION FOR ADDITIONAL DETAILS...WITH THE FORECAST
EMPHASIZING RECENT ECMWF/GFS RUNS BUT DISCOUNTING THE
CANADIAN/UKMET WHICH APPEAR TO BE MORE OUTLIER SOLUTIONS.

ORAVEC/KOCIN

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

24HR QP VT 26/12Z
 0.01 492612 498621 504634 514660 519671 524683 529696 532709
      539741 541751 543759 542773 542782 543790 544796 544799
      541801 535808 527816 520819 514820 509818 500815 491810
      484806 479802 476801 473801 455799 449797 449791 448787
      450785 455781 461774 463771 463767 461760 460751 461746
      463740 466737 471736 473737 476736 477732 476728 474723
      467714 464713 461714 454717 451716 450713 445713 432717
      392735 379737 365740 351743 342748 338751 333753 325758
      315764 307770 299777 290784 282791 273797 267803 259808
      251815 243820 233826 228828 224828 227817 229812 233809
      237799 240795 244791 259782 274766 288751 301736 308730
      314723 328706 332701 337697 345692 354687 363681 368678
      373675 381669 385664 386659 389646
 0.01 505148 504143 502139 499137 496136 489133 483129 480127
      476126 472131 470134 470140 477138 481139 485141 492144
      494146 498148 502149 505148
 0.01 493222 494217 494213 492211 489209 483209 477210 456213
      436218 429218 424219 422222 426225 427230 426235 420235
      415237 409237 407239 407244 408247 411248 415251 421251
      432249 444250 465248 471247 476247 478245 479240 479236
      478234 472235 469232 468229 469225 471223 476222 486221
      491223 493222
 0.01 483161 483158 479157 473154 468149 466144 467139 468133
      469128 472123 473118 474116 475104 474097 473091 469086
      467083 467078 468058 468048 467044 467038 466030 463023
      463018 462014 461005 461985 464966 462926 461920 460917
      457919 455920 454924 453930 450939 449941 445942 434948
      426959 423964 421971 417977 415980 415985 411999 405011
      400014 397018 393023 388027 383031 378033 374041 374046
      384056 385059 383063 384066 383069 380064 374060 373059
      373055 374050 363052 356054 349055 346056 343054 336053
      328051 323055 319060 315065 310076 306081 299082 291089
      289097 290102 292104 295105 302106 305108 307111 309115
      308120 309123 312125 314127 316126 320121 322115 326111
      329110 331112 334112 337111 340113 342116 348118 350122
      352129 353133 356135 361139 365136 371135 378138 384141
      387143 388146 387151 388155 389159 387162 385166 385171
      383179 382186 386192 386187 386183 390182 393184 397182
      404179 407175 407167 410159 411152 408150 404151 402152
      399150 399146 400143 402140 405139 409139 411137 413134
      415135 415143 416150 415157 415161 418162 422163 423167
      418170 416175 422175 428173 431168 427163 426155 428145
      433130 436126 439127 438131 436136 435143 436148 436153
      437158 443164 445169 446178 441182 438192 439197 441203
      443206 445206 452197 459183 459179 458176 457172 458166
      462164 469165 478165 482163 483161
 0.01 444742 440739 435740 431742 430747 431752 433759 434763
      438766 439760 440755 441750 443745 444742
 0.01 430788 429779 425777 419783 415783 413786 405787 402788
      400790 396791 393793 390794 388797 383800 380805 378808
      379809 383809 385806 387805 390802 393801 395798 399798
      401795 408799 412800 419804 422806 427800 430788
 0.01 389109 388106 386105 381104 378106 375105 373100 371101
      369104 366107 361105 358104 352099 349090 348081 350079
      354080 357080 359076 358071 355068 351067 347068 344072
      343078 342081 339084 339088 340093 343098 347107 353112
      356115 361116 367117 377117 383113 389109
 0.01 364186 365184 364184 363183 361183 359182 357182 356182
      354181 353182 352183 351184 350185 349185 349186 351186
      353187 355187 356187 358188 360188 362188 364187 364186
 0.01 339168 336166 331164 327162 324160 320160 317164 319167
      322169 328172 331174 335174 338170 339168
 0.25 469620 475624 480628 485632 488639 488650 486658 478666
      479671 480678 479683 475683 461683 454685 448688 437695
      424704 410709 393714 387717 381717 375714 366715 358716
      353713 353707 354703 358698 363693 369689 383681 392674
      414655 424645 427640 429634
 0.25 538759 535755 533749 529734 525721 521707 517695 511686
      507683 502685 496694 494701 494708 497724 496732 494739
      492743 490749 488755 487763 492775 498784 505790 509792
      513794 519793 522791 527788 530783 534773 536763 538759
 0.25 460240 460237 457236 454236 451236 448236 446236 443237
      440239 439241 441243 445244 447243 450243 453243 456243
      458242 460240
 0.25 456103 457098 457093 455087 456077 455069 452054 450039
      448023 447015 445008 441997 436999 431002 418022 414028
      412033 411040 408046 402047 399047 396049 396054 398055
      404058 403064 398069 391068 388075 386079 383076 379072
      377066 372063 368062 366063 368068 371071 374085 383089
      387091 390089 391086 395087 399085 402080 408079 411084
      411093 413100 411103 409104 405107 400110 389114 381121
      379125 381128 387127 392124 397122 402122 404123 407123
      411119 418119 421119 423122 424126 423131 422137 422140
      424138 429123 430109 431105 432102 435102 437100 448098
      452103 456103
 0.25 453086 452083 449081 448079 446077 444075 441074 441076
      441079 442082 444085 445087 449088 452088 453086
 0.50 528761 528755 526749 521742 519736 515735 511736 509739
      505748 499755 498761 500765 503769 506771 510772 512776
      517777 521774 522772 521770 528764 528761
 0.50 468644 467639 463638 456639 448643 444649 441656 435661
      422669 416674 412680 412683 414687 421686 438682 453679
      462676 468673 470669 469666 464657 463654 465651 468644
 0.50 444041 444038 444036 443035 442034 440036 440038 441041
      443042 444041
 0.50 428087 429084 429082 428081 427080 426082 425084 426086
      428087 428087
 0.50 424055 423053 422048 422044 422040 421037 419036 417037
      415041 414043 413047 413050 411054 413057 416057 418056
      421057 424055

24HR QP VT 27/12Z
 0.01 535215 536208 536203 535193 530171 525165 519159 515155
      512157 509159 510162 511165 512167 510170 503168 497161
      495157 494150 493147 494144 498141 497138 493136 485131
      480126 476118 476109 473106 469105 466107 464111 467120
      467123 465122 463119 463124 465127 469131 470135 471139
      475140 478142 480145 478147 474147 465143 461143 457145
      454151 453156 456162 459160 462161 470170 473167 477165
      480169 481175 488188 490197 484200 476207 455218 442221
      432227 437231 442231 451225 460227 462230 462235 445238
      440242 432246 427250 423255 426257 430256 437253 445250
      453248 456249 459254 465258 471255 475257 476260 481268
      485277 489286 492290 496294 501293 505292 508289 513282
      516276 518271 520264 521260 522253 521248 518243 516237
      516231 518226 522224 525224 529225 533220 535215
 0.01 518077 519071 517067 513061 508057 501058 494059 491060
      489065 491071 493081 494084 496083 502079 505079 510080
      512083 515082 518077
 0.01 484863 487858 495850 496834 490812 484784 480777 470783
      452808 425844 390878 360896 329893 307870 295866 282871
      263884 257908 262924 275938 285951 283964 285981 290992
      300995 310989 324978 332985 331998 321013 303030 304039
      312047 311053 302059 295066 290075 281075 275072 265071
      258073 255074 255078 260085 261090 264092 271097 279099
      287100 291101 294103 303111 306113 311113 315110 326096
      335091 338083 336074 340067 348072 349084 354094 367100
      381102 389099 393101 392107 384116 378121 375129 380133
      389129 397121 407115 416115 420111 421105 420091 426069
      432036 441005 449978 460954 472923 477898 480889 483867
      484863
 0.01 440201 445208 449203 448202 448201 446199 446198 445196
      443195 441195 440194 438194 439197 440201
 0.01 422155 422152 423150 423148 423145 423143 421142 421143
      421145 420147 420149 419152 418152 418154 419156 420157
      422155 422155
 0.01 322036 322042 329041 337032 348018 347012 345009 343011
      336019 330027 324034 322036
 0.01 247810 255813 261816 270810 276811 273823 273827 283829
      295824 306821 314812 310799 305793 298790 288793 283794
      278792 269789 265790 261793 251797 246803 244808 245811
      247810
 0.25 511271 513266 514261 513256 512254 510251 507250 505250
      503252 502257 501259 499263 499269 500271 502274 505274
      507274 510273 511271
 0.25 396066 394064 393065 391066 389068 389070 390072 391073
      392073 394071 395069 396066 396066
 0.25 383054 383051 381049 379046 377044 375042 374042 372044
      370046 367048 366050 368052 370053 374053 377053 381055
      383054
 0.25 379080 381076 381072 380068 378066 375064 373064 370064
      368066 370068 372071 373073 374076 376080 377081 379080
 0.25 374947 373944 370941 365941 363938 361931 359927 355926
      349929 343934 332943 328947 323952 317956 312960 310964
      311966 319968 324969 332966 340966 345967 347969 350970
      353968 357963 362958 368953 374947
 0.25 312090 310086 308083 305080 299080 291081 287081 283080
      274077 270077 266078 270086 272089 276091 287092 298094
      303095 309094 312090
 0.25 300901 300891 299888 296886 290889 284893 280900 280908
      283915 286921 291922 294920 299914 300905 300901
 0.50 304089 302087 301085 299085 297084 296084 295084 294084
      292085 291085 292086 293087 294088 295088 297089 299089
      300090 302090 304089 304089

24HR QP VT 28/12Z
 0.01 518258 520238 519225 527217 533206 530177 518157 520140
      515131 506119 511113 517100 508078 487066 471039 463045
      463058 469077 470084 465087 460077 449066 439069 444076
      450084 446093 434095 417101 407124 411155 416225 420245
      435252 460255 465255 467257 474261 494283 498285 502286
      508280 513274 516267 518258
 0.01 357968 390947 418937 450914 487849 500772 491714 476672
      464656 453662 420738 383798 369798 350788 338800 330801
      321800 309807 305809 292807 288807 285805 279802 276797
      272794 266796 264798 264802 264807 266810 271814 279817
      286818 293818 300818 306820 312821 314830 298853 276877
      259897 256926 249953 246977 252988 261992 278991 301990
      325986 348975 357968
 0.01 493964 490982 490013 495053 501052 508023 505986 502975
      502970 501965 498957 496954 494957 493964
 0.01 472933 471944 469968 472982 479981 484968 485938 482932
      477924 475924 475930 472933
 0.01 418076 417069 412063 403062 401064 396064 391068 385072
      385079 389086 394090 403091 406089 410089 414085 418076
      418076
 0.01 316049 318036 316023 310015 309005 300002 287015 278036
      278040 279049 284059 290073 292092 300095 309078 316049
 0.25 511249 511241 509234 504224 502217 501210 502204 504197
      507192 509190 510184 510180 508177 505174 501170 498166
      495160 494153 489141 487136 484132 477124 472120 467120
      464125 462132 456142 452146 449148 439146 437147 436153
      439159 444173 444186 445192 450194 457189 460186 464181
      467179 473181 477183 483186 485189 486193 482198 479201
      477203 466209 449210 434211 432222 438233 452242 462245
      474248 486259 497271 501271 504270 505266 508261 511249
 0.25 502251 500245 498242 496238 493233 491229 487227 483227
      481231 483235 485239 488243 489247 494251 497253 500252
      502251
 0.25 477834 487791 487772 487758 486749 481728 478717 475710
      471704 468703 466707 463715 463720 465729 465751 459784
      449826 443852 444875 459871 477834
 0.25 447111 448109 447107 447106 446106 444105 442106 441108
      440109 439110 440111 442112 443112 445112 447112 447111
 0.25 385883 389864 385852 379843 369839 366838 356834 352832
      349829 345827 340826 337825 333827 325834 320841 307854
      302862 296868 285881 279890 275898 274903 268930 270950
      281968 289971 295971 299969 305964 320953 334943 342936
      347929 352922 359915 366908 372902 378895 383887 385883
 0.50 371887 373874 371864 363852 354848 348846 339841 327845
      323847 316851 311856 306861 285885 280899 276915 275930
      279948 284954 292958 300957 310950 320941 337922 340919
      346914 357905 363900 369894 371887
 0.50 496223 496215 494210 488206 482206 472210 467212 462213
      451215 446216 441219 443223 446225 449226 458232 463231
      467227 472225 476222 483223 488223 493226 495225 496223
 0.50 480241 480239 479237 478236 477235 476234 475235 474237
      475239 475240 477241 478242 480241
 0.50 486172 488165 487159 487155 485151 482148 480147 473142
      465141 461148 458155 457161 459164 465168 472171 478175
      482176 485174 486172
 0.50 477805 477802 477800 477797 477795 476794 475794 473795
      473796 472798 470801 470802 470803 469806 469808 470811
      471813 473814 474813 476810 476807 477805 477805
 0.50 459178 460175 460173 458172 456173 455174 454175 454176
      453178 452181 452183 453185 455185 456184 457183 457182
      459180 459179 459178
 1.00 485217 485215 482212 481211 479211 475212 474213 472214
      469215 467217 469219 472218 475218 477217 480218 483219
      485217
 1.00 350877 351872 350868 346869 337874 321863 313864 309867
      301872 293880 287889 284900 282906 282910 280926 283940
      286943 292943 296941 298939 307929 318918 321915 328907
      335899 342892 348884 350877
 1.50 324892 324887 322884 318880 311878 306878 299880 294885
      291889 289896 288903 284918 284930 286934 290938 293937
      296935 299929 305918 313908 321898 324892
 2.00 313898 313893 310890 302887 295893 291899 290910 288920
      288931 291932 294932 296928 300920 304912 310905 313898
 3.00 301907 299907 298910 299910 301908 301907

$$




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