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Quantitative Precipitation Forecast (QPF) Discussion
 
(Caution: Version displayed is not the latest version. - Issued 0619Z Dec 21, 2014)
 
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Abbreviations and acronyms used in this product
 
Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White


QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
119 AM EST SUN DEC 21 2014


PRELIM DAY 1 QPF DISCUSSION
VALID DEC 21/1200 UTC THRU DEC 22/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...


...PACIFIC NORTHWEST INTO THE CNTL/NORTHERN ROCKIES...

THE SCREAMING E/W PAC UPR JET (175 kTS OR SO) AND STG ONSHORE FLOW
PATRN WILL PROVIDE ONE MORE DAY OF HEAVY TO EXCESSIVE RAINS ACRS
PARTS OF THE PAC COAST REGION...WITH SIGNIFICANT RAINS AND HIER
ELEVS SNOWS SPREADING EWD ACRS THE NRN INTERMOUNTAIN REGION AND
SEWD INTO THE CNTL ROCKIES.  BY LATE IN THE DAY 1 PD..BUILDING
HEIGHTS OFF THE WEST COAST WILL HELP WEAKEN THE INTENSE ONSHORE
FLOW PATRN AND SLOWLY SHIFT WEAKENING E/W FRONTAL BNDRY NWD
THROUGH OREGON.  WHILE BROAD ONSHORE FLOW PATRN IS EXPECTED TO
IMPACT MOST OF THE PAC NW REGION...BY FAR THE HEAVIEST RAINS ARE
EXPECTED ACRS THE CNTL/SRN OREGON COASTAL RANGES INTO THE OREGON
CASCADES WHERE MAIN AXIS OF GREATER THAN 1.25 INCH PWS ALONG WITH
40 KT PLUS WLY 85H FLOW IS EXPECTED TO PERSIST FOR AT LEAST THE
FIRST 12 HRS OF THE DAY 1 PD.  MANUAL QPF CONTINUES TO LEAN TOWARD
COMBO OF SSEO MEAN AND GENL HI RES GUIDANCE GIVEN BETTER
TOPOGRAPHIC RESOLUTION..WITH MANUAL QPF AMOUNTS OF 2 TO 4+ INCHES
EXPECTED OVER THE OREGON CASCADES.  1 TO 2 INCH LIQUID EQUIVS ARE
LIKELY FARTHER E ACRS THE BLUE MTNS..SAWTOOTH RANGE...NRN
WASATCH...TETONS...AND NRN CO MTNS WITH LOCALLY HIGHER AMOUNTS IN
THE MORE FAVORED WRN FACING UPSLOPE AREAS.  THESE ADDITIONAL RAINS
WILL LEAD TO SOME LOCAL STORM TOTAL AMOUNTS CLOSE TO 10 INCHES
OVER WRN OREGON...AND LIKELY EXACERBATE ANY ONGOING FLOODING
PROBLEMS. REFER TO THE LATEST SUITE OF WINTER WEATHER PRODUCTS FOR
DETAILS ON THE WINTER WEATHER POTENTIAL OVER THE INTERIOR NW AND
CNTL ROCKIES.

...CNTL U.S...

STG JET PUNCHING INTO THE PAC NW WILL GRADUALLY LEAD TO DVLPMENT
OF LEE SFC LOW OVER THE NRN HI PLAINS ON SUN/SUN NIGHT WITH JET
EXPECTED TO DIG SHARPLY SEWD THRU THE INTERMOUNTAIN WEST.  AN AREA
OF HEIGHT FALLS/PVA IS EXPECTED TO SUPPORT AN AREA OF MIXED WINTRY
PCPN FROM ERN MT INTO THE DAKOTAS SUN/SUN NIGHT AS LOW PRES AND
ASSOCD PAC FRONT PUSH EWD ACRS THE REGION.  THE NAM WAS THE MOST
GENEROUS WITH PCPN ON THE BACKSIDE OF THE LOW THROUGH ERN MT BUT
THOUGHT PERHAPS IT MAY BE A LITTLE TO DVLPD WITH MID LEVEL LOW
DVLPMENT AND ASSOCD VORT COMPARED TO MODEL CONSENSUS..SO LEANED
AWAY FROM 00Z NAM AMOUNTS OVER ERN MT.   EAST OF THE
LOW...STRENGTHENING SELY LOW LEVEL FLOW/WAA PATRN IS EXPECTED TO
LEAD TO AN AREA OF MAINLY LIGHT WAA PCPN ACRS THE UPR MS VALLEY. 
WITH THE EXCEPTION OF THE 12Z UKMET...THERE IS GENL SUPPORT FOR AN
AXIS OF .10 TO .25 INCH AMOUNTS ACRS PARTS OF NRN WI INTO THE U.P.
OF MI BASED ON 00Z NAM/GFS AND CANADIAN GEM WHICH WERE FOLLOWED
CLOSELY.

...SOUTHEAST U.S....

SLOWLY BACKING FLOW AHEAD OF SHARPENING UPSTREAM LONGWAVE TROF
WILL HELP DRAW DEEPENING TROP MSTR NEWD FROM THE SRN GULF/WRN
CARIBBEAN REGION TOWARD THE ERN GULF OF MEX ALONG QSTRNY FRONTAL
BNDRY..WITH PWS INCREASING TO OVER 1.75 INCHES ACRS CNTL/NRN FL
REGION BY MON MRNG.  THE COMBINATION OF INCREASED MSTR FLUX INTO
THE FRONT..AND STRENGTHENING RT ENTRANCE REGION JET SUPPORT WILL
LEAD TO AN INCREASING THREAT OF RAINS/TSTMS ACRS NRN FL AND
LIGHTER RAINS NWD AS FAR NORTH AS SRN VA.  MANUAL QPF GENLY
FAVORED AN ENSEMBLE APCH GIVEN SMALL DETAIL DIFFERENCES REGARDING
TIMING OF WEAK UPR DISTURBANCES LIFTING NEWD ACRS THE NRN GULF AND
CONVECTIVE POTNL OVER NRN FL.  GENL 1+ INCH AMOUNTS ARE PSBL WITH
LOCALLY HEAVIER AMOUNTS WHERE STGR CONVECTIVE STORMS DVLPG AND
PSBLY TRAIN.

SULLIVAN

GRAPHICS AVAILABLE ON THE WEB AT www.wpc.ncep.noaa.gov/qpf/qpf2.shtml


24HR QP VT 22/12Z
 0.01 499321 491307 489295 489281 488270 486263 479257 473250
      468249 466248 464250 461255 460262 459266 460270 459275
      456281 455286 453286 446288 442283 437275 432266 429260
      422254 417253 411254 407253 403250 399250 395247 391245
      390242 386234 382227 378224 375221 381222 391224 397224
      397221 396218 388211 384209 383202 384200 388198 391197
      395199 399201 402203 404206 407207 409206 409201 411199
      414196 419195 422192 422188 420185 415179 410172 404169
      398173 395173 393170 395165 397163 396160 395150 394144
      392138 388131 380126 378123 379120 381116 404093 402090
      398092 393088 386088 378084 374082 373080 373075 373071
      370067 374061 368057 359056 363054 367054 374050 377052
      379055 382058 386059 393053 396050 399045 405042 408042
      411043 418048 425053 427057 428061 428065 426068 424075
      424083 429085 432089 435090 438089 442092 446091 452091
      456095 462097 465097 465093 466090 466087 464085 460083
      454082 450084 446082 441076 437077 435074 433070 435068
      442064 442058 441054 440050 436048 432045 427044 424040
      421037 417034 414029 413023 411017 409006 406997 399994
      396995 390995 382997 377986 373979 371973 366966 361967
      358967 353958 355955 353951 342947 341945 343941 346932
      350924 356918 364914 371909 374909 378906 384906 389908
      401908 404910 409909 415907 420905 422900 426894 432890
      435887 437884 442876 447865 450855 451850 453846 458837
      461832 463827 465818 468816 473815 480819 486829 510846
      510852 512861 513873 514879 514887 513892 510897 508901
      508905 509906 515913 517918 516920 512931 510933 507937
      504947 502952 499955 493955 489952 486954 487961 487971
      484995 483001 482006 483009 487020 489025 491030 494036
      495038 498039 501041 503042 510048 517054 522060 529069
      535082
 0.01 535082 541095 547112 549131 551139 551146 550146 544147
      541146 539143 527135 524134 521131 516127 509113 507106
      502103 498103 493109 491112 490116 492122 496130 498133
      496134 491129 488122 487119 484116 482114 478113 474114
      474121 480124 487128 491133 500142 506146 511152 520164
      528175 530183 531186 533190 539194 542198
 0.01 525238 524236 524235 523232 522229 521226 519228 519231
      518233 517235 517238 517239 519240 520241 522242 524240
      525238
 0.01 489195 488191 485188 481183 479179 479176 477175 473176
      471180 467187 463192 458197 459200 463202 467204 470202
      476199 482197 489195
 0.01 449689 447678 444675 440672 434671 431672 429676 427681
      424684 415686 409691 405698 404703 404709 403713 405717
      410723 416729 421734 424735 429733 432730 432727 431721
      434718 437714 436711 433710 430713 428713 426710 427705
      429702 434699 438698 441696 445694 448691 449689
 0.01 370194 369192 364189 360187 356188 351188 349190 350193
      353197 354195 359195 364196 368196 370194
 0.01 224878 230881 238884 244882 249882 250887 251891 252895
      256903 258906 257911 253919 249938 246945 246954 246965
      249974 255978 257980 261980 268976 274970 276964 276953
      275932 277923 279912 284897 287890 291883 295877 300869
      311858 317854 324849 340845 345845 348842 350840 352835
      355826 357823 361821 366816 370813 371810 374792 375790
      374783 373770 372764 370759 367750 364743 362738 359735
      355730 353727 351722 350715 348712 344702 339695 337694
      332695 324694 321696 317699 311703 309706 309711 307731
      308743 308752 309763 305771 299784 290797 282801 277802
      274804 270805 267807 260813 255817 251823 249826 248829
      246838 239843 234849 221857
 0.25 522262 515253 513250 512246 510237 500214 494204 491202
      487201 481203 469207 457209 453211 447211 446210 447204
      450198 454194 456189 464180 465177 465173 467169 477161
      483162 483158 480157 478154 473148 470144 470142 473142
      480142 483142 485145 489150 491151 493148 492143 490137
      485131 479127 474126 472124 466121 464120 461123 461126
      458127 446128 429144 426143 426137 426133 428129 432124
      469110 471109 470104 465106 463104 458102 454097 431092
      426090 425094 426098 414106 411100 409097 406099 404104
      400107 390111 385117 386122 388123 410125 415129 419133
      417139 414146 412149 408148 403154 404157 408157 413162
      416166 422170 428173 433170 436167 440167 442169 443175
      439180 436188 437197 438200 438206 435208 432209 423201
      419200 418204 422207 424212 425215 423217 419223 419230
      415229 411224 408229 406231 403233 399237 402242 408244
      417247 423248 430248 441246 452243 464239 466234 462232
      450232 447232 447230 451228 456226 464227 468225 474221
      476219 480220 486223 491224 494228 496236 500243 501248
      502254 499254 495250 491245 488242 486244 488252 494266
      500277 503278 505276 506269 508265 511269 514274 519277
 0.25 519210 521202 521196 520189 519185 515176 510167 508163
      506161 502161 498163 496168 496171 497177 496185 498190
      500193 507193 510194 512198 516206 519210
 0.25 481242 482239 482237 481235 480234 479232 478232 476232
      474232 473234 472236 472237 472239 473241 475242 476243
      478243 480242 481242
 0.25 474093 472091 471090 469090 468093 469094 471094 472095
      474093
 0.25 470890 471884 469879 467878 464878 458884 454889 448894
      446901 446907 446912 452916 456917 460916 464915 466912
      466907 464903 468895 470890
 0.25 450078 449078 448076 447075 446074 445072 443071 441070
      440071 439072 440072 441073 443074 444075 446077 448078
      449078 450078
 0.25 449044 449041 448040 446041 446043 446044 448044 449044
 0.25 425232 424229 422228 421228 422230 423231 424232 425232
 0.25 428187 427184 425186 426188 428187
 0.25 398239 398237 396238 398239 398239
 0.25 418067 419062 418059 414057 402053 397055 393058 386063
      381072 377072 376076 377080 380080 385078 393082 396084
      398083 402079 406077 411077 415074 417069 418067
 0.25 348758 348751 346744 341736 339733 334732 325738 319746
      318749 317755 317761 316767 312777 307785 302792 297800
      290808 277819 271827 266836 259843 252848 244852 236858
      229866 229870 233871 238872 243871 255869 261868 268868
      271870 274873 276878 277881 279881 286875 307843 313836
      319830 324821 330812 334802 337794 344774 347765 348758
 0.25 275906 275899 274894 270896 268900 266911 262921 258931
      255941 255948 258952 261953 263952 266947 268937 270925
      273913 275906
 0.50 499263 499262 499261 498259 497257 496257 495255 493254
      492256 493257 494259 494260 496262 497262 497263 499264
      499263
 0.50 500238 500235 500234 498233 497234 498236 498237 499238
      500238
 0.50 493217 493212 492208 488205 482205 476206 467210 455212
      444213 437213 432215 426218 422221 421224 423226 429231
      430234 425235 418233 411233 409235 408239 414242 421245
      429246 439243 451241 456239 460235 457233 454233 447234
      443232 447228 452226 458225 464224 468222 473219 476218
      480219 484221 488221 493217
 0.50 479239 479236 478234 476235 475236 475237 475238 477240
      478239 479239
 0.50 486136 485133 483131 480130 478129 474129 471127 468127
      468128 469133 470135 471138 473140 477139 479139 482139
      484138 486136
 0.50 472156 469147 464139 464136 462134 459133 456130 453132
      447137 446139 435145 431151 430156 433162 440163 444164
      446168 447178 441183 440189 443193 452193 458185 463179
      461174 458171 457167 458162 462161 466160 469159 472156
 0.50 455105 454100 452097 448096 445099 431093 426093 428097
      429101 425102 412108 410100 407100 405105 402108 399109
      391112 389114 387118 395119 400120 403122 406123 409122
      414123 417123 425122 430121 432118 438113 445110 445104
      447102 449103 452105 455105
 0.50 452112 451109 449108 447109 449111 449112 450114 452113
      452112
 0.50 427208 426207 424207 424208 425210 427208
 0.50 420161 421159 421157 421155 421152 420150 419150 417151
      417152 416153 416156 415158 416160 416161 417163 419162
      420161
 0.50 422143 423141 422139 420140 420142 421144 422143
 0.50 417064 415060 411059 406055 401055 399055 393060 387065
      387074 392079 396080 400078 404073 409075 413074 414068
      417064
 0.50 381076 382074 381073 380073 378074 378076 379078 381076
      381076
 0.50 341759 341754 339749 335743 331743 328746 324754 322762
      320769 316777 314781 311784 303796 293809 284820 279825
      274832 266845 260850 252854 245857 240861 240865 246865
      257863 263859 272858 282858 286856 289852 292845 297840
      309829 314823 317817 323801 326792 329786 334779 337771
      341759
 0.50 265939 265937 266935 266933 266931 265929 264929 263929
      261931 261932 261933 260935 260937 259939 259941 259942
      260943 261944 263943 264941 265940 265939
 1.00 486212 484209 483209 481208 480208 479208 478209 476209
      474211 473211 472213 471213 472215 473215 475215 477216
      478216 480217 482217 482216 483215 485215 486212 486212
 1.00 470218 470215 469214 463213 460215 456215 451213 447214
      439214 431217 424221 423225 428227 436232 444229 451225
      458222 466220 470218
 1.00 467149 460143 458143 455144 451151 447152 443150 438145
      434152 434153 437158 442159 446159 449162 450165 450168
      449173 450178 447182 444183 444187 448189 451188 457184
      461178 459176 457177 453169 453166 454162 464151 467149
 1.00 452237 449235 444235 438234 431236 425237 416235 414237
      415240 422244 429244 435242 442240 447238 452237
 1.00 453103 453102 451100 453102 453103 453103
 1.00 441108 437105 433099 432099 432103 432106 428104 423105
      421107 423109 423112 421112 415113 410112 409104 400110
      394112 390115 390117 393117 399117 404119 411120 422118
      426115 431112 436110 441108
 1.00 415064 414062 412063 412064 414065 415064
 1.00 412071 411068 408066 407065 403064 401065 399069 398070
      396073 397077 400076 402074 403070 406071 410072 412071
 1.00 393073 393071 392069 392068 391068 390068 390070 390073
      392074 393073
 1.00 305810 303808 300810 295815 290819 285824 281829 278836
      280838 284839 291835 295830 299823 302817 305810
 1.50 455221 456216 454215 449215 444215 441215 438216 433218
      427219 426220 424225 430227 435230 440229 444227 449225
      453222 455221
 1.50 459180 459179 457178 456179 457182 459180 459180
 1.50 454176 454174 453172 451171 450173 450175 451176 452178
      454176
 1.50 450185 451183 450182 450183 448183 447184 448187 450186
      450185
 1.50 439239 439238 437237 436238 435238 433238 432238 431239
      433240 435240 437240 439239 439239
 1.50 428242 428240 426239 425238 423238 421237 419237 418236
      416236 415239 417240 419241 420242 422242 424243 426243
      427243 428242
 1.50 441154 440151 439151 438149 437151 437153 438154 439155
      441154
 1.50 418116 413115 410115 408112 409109 407105 406107 403111
      400112 396113 392114 396116 401116 406118 411118 415117
      418116
 1.50 409068 408067 407067 405066 403067 403068 405068 406069
      408069 409068
 1.50 401074 399072 397073 397074 399075 401074
 2.00 455218 453216 449216 444216 438216 433218 427220 425221
      425224 430226 437229 442227 446225 451222 455218
 2.00 453176 453175 452173 451173 451174 452176 453176
 2.00 424241 422240 421239 419240 421241 422241 424241 424241
 2.00 409117 408116 406115 405115 404114 403113 402113 403114
      404116 406117 408117 409117
 2.00 407112 407110 407108 405109 404111 405113 407112 407112
 3.00 449222 449219 447217 442217 438218 434219 431220 427221
      425223 430225 435226 439225 443224 446223 449222
 4.00 447219 447218 445218 443218 442218 440219 439219 438220
      436220 435220 436222 437223 439223 441222 442222 443222
      445221 447220 447219
 4.00 434222 432222 431221 429221 430222 432222 434222