Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 191845
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
145 PM EST SUN NOV 19 2017


PRELIM DAY 1 QPF DISCUSSION
VALID NOV 20/0000 UTC THRU NOV 21/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...PACIFIC NORTHWEST/NORTHERN ROCKIES...

TONIGHT BEGINS A SEVERAL DAY PERIOD OF RAIN IN THE
CLIMATOLOGICALLY WET REGION FROM WESTERN WASHINGTON TO NORTHWEST
CALIFORNIA. PERIODS OF MODERATE AND HEAVY RAIN WILL
OCCUR...LEADING TO ACCUMULATIONS RANGING FROM 2 TO 5 INCHES AT THE
LOWEST ELEVATIONS TO MORE THAN 10 OR 15 INCHES OF LIQUID IN THE
FAVORED WEST AND SOUTHWEST FACING TERRAIN THROUGH FRIDAY. THE
EVENT BEGINS WITH A LEAD SHORTWAVE DRAGGING A SUB-TROPICAL
MOISTURE PLUME ONSHORE FROM NOW THROUGH MONDAY...FOLLOWED BY
CONSOLIDATION AND AMPLIFICATION OF A DEEP OFFSHORE TROUGH WHICH
WILL ACCESS A BROAD AND RICH MOISTURE PLUME GOING INTO MID WEEK.
THE LONG TERM RAINFALL IS EXPECTED TO PRODUCE RIVER FLOODING...SEE
PRODUCTS FROM LOCAL OFFICES AND THE NORTHWEST RIVER FORECAST
CENTER FOR DETAILS. ADDITIONALLY...WE MAY SEE WPC OUTLOOKS FOR
EXCESSIVE SHORTER TERM RAINFALL RATES AND ASSOCIATED IMPACTS
EXPAND IN COVERAGE AS THE FORECAST CONTINUES TO COME INTO FOCUS.

IN THE DAY 1 PERIOD...00Z THIS EVENING THROUGH 00Z TUESDAY...THE
MODELS HAVE STRUGGLED SOMEWHAT WITH THE SHORTWAVE DETAILS IN THE
MID LEVELS AS A SMALLER WAVELENGTH TROUGH PASSES BENEATH SHORTWAVE
RIDGING. THE RESULTING ONSHORE FLOW...HOWEVER...IS SOMEWHAT
INDEPENDENT OF THE SHORTWAVE STRENGTH. GENERALLY WE FAVORED THE
MORE SHARPLY DEFINED SYSTEM DEPICTED IN THE CANADIAN GLOBAL
MODEL...TEMPERED A BIT TOWARD THE 06Z GFS. THE 12Z NAM AND GFS
CAME IN FLATTER THAN DESIRED...BUT THE 12Z ECMWF TRENDED TOWARD
OUR PREFERRED SOLUTION. THIS TREND BROUGHT THE ECMWF QPF FOR THE
24-HOUR PERIOD MORE IN LINE WITH THE MANUALLY MODIFIED WPC QPF AND
SOURCES THAT WERE USED TO CONSTRUCT IT...SUCH AS THE WRF-ARW AND
NAM CONUS NEST.

DEEP LAYER FORCING SLIDES SOUTHWARD THROUGH WA/OR DURING THE
PERIOD...AND A SOMEWHAT SEPARATE STREAM OF ENHANCED MID LEVEL
GRADIENTS AND ONSHORE FLOW DEVELOPS INTO FAR SOUTHWEST OREGON AND
NORTHWEST CALIFORNIA AT THE SAME TIME. THE RESULT IS A FAIRLY EVEN
DISTRIBUTION OF 1 TO 3 INCHES OF RAIN UP AND DOWN THE COASTAL
MOUNTAIN RANGES AND THE CASCADES...BUT WITH HEAVIER TOTALS IN THE
FAVORED LOCATIONS. MODERATE TO HEAVY TOTALS OF BOTH RAIN AND SNOW
WILL ALSO EXTEND INTO INLAND TO THE HIGH TERRAIN IN NORTHEAST
OREGON AND OVER INTO ID/MT. SEE THE WPC HEAVY SNOW
DISCUSSION...QPFHSD...FOR WINTER WEATHER DETAILS.


...ELSEWHERE...

THIS AFTERNOON AND EVENING A PROGRESSIVE CYCLONE AND ASSOCIATED
COLD FRONT WILL LIFT AWAY FROM MAINE...LEAVING IN ITS WAKE ONLY
LAKE EFFECT SNOWS OFF THE EASTERN GREAT LAKES...AND A BROKEN LINE
OF SHOWERS/FEW STORMS DROPPING THROUGH FLORIDA. THE SOUTHERN
PORTION OF THE FRONT IS FORECAST TO STALL...AND CONVERGENCE WITHIN
THE FRONTAL ZONE ALONG WITH GRADUAL UPSTREAM TROUGH AMPLIFICATION
WILL MAINTAIN SOME PRECIPITATION IN THE VICINITY OF SOUTH FLORIDA
AND THE KEYS THROUGH MONDAY. MORE WIDESPREAD RAIN WILL LIKELY
DEVELOP OVER THE PENINSULA BY TUESDAY.

BURKE

GRAPHICS AVAILABLE ON THE WEB AT
WWW.WPC.NCEP.NOAA.GOV/QPF/QPF2.SHTML

24HR QP VT 21/00Z
 0.01 529199 530191 531183 530175 528171 525160 524154 524147
      523136 522125 522120 520115 518109 516104 511096 508093
      502092 499090 496092 495105 494111 492115 490121 487123
      482121 479117 477107 483099 484093 484090 482089 479086
      475087 471087 469086 463094 459094 457091 451075 448071
      444068 438069 438073 445079 448081 450085 448090 445092
      442094 437094 433093 429090 426091 427096 425102 421105
      418113 413112 411108 409105 407108 403111 399111 398113
      400116 404119 409120 413122 414127 410139 404148 402152
      402158 403162 404168 403179 407185 409191 409198 406201
      403203 384194 380192 377194 380201 386207 385216 383221
      380223 377227 376232 376238 378244 382254 385261 389269
      394277 401281 411284 421287 431287 440286 455282 468273
      479264 494254 499248 503247 506244 507240 509232 510217
      509208 509204 511203 515204 521205 525204 529199
 0.01 534011 535997 535985 534977 533965 535955 535943 535920
      533909 531900 527885 524876 521870 518864 514858 510854
      504850 499848 497847 495849 492856 490865 489872 489878
      491881 491886 493891 495899 498906 500914 500926 500938
      500960 501970 502981 504998 505003 506007 509014 517023
      521023 523021 528019 534011
 0.01 480193 478191 475191 473192 469191 467192 465194 462196
      461198 463199 467200 469199 471198 474197 476196 479195
      480193
 0.01 482857 480851 476845 473840 469836 462828 460823 458815
      457807 454799 449786 444774 443757 445749 448744 448740
      446738 443738 433739 426741 423741 421743 420749 421752
      421756 420761 422766 423770 421773 417775 408782 397788
      392790 387793 383797 381802 379808 380810 384809 395803
      397799 402795 406794 408796 409805 412819 415823 417817
      420811 423807 426806 429807 431814 439818 445821 448825
      451832 452841 449846 445851 439858 440861 444861 448858
      452854 455849 460850 461857 465871 467879 468889 470896
      471895 473888 473880 472863 473859 475858 478860 482857
 0.01 466705 465699 463698 460699 457702 450705 444709 440711
      438714 440718 443719 445718 446721 443723 443730 451729
      456723 458716 463709 466705
 0.01 440728 439727 438726 437726 435726 434726 432726 430726
      428727 427727 426729 425731 425732 427733 429732 431732
      432731 434731 436730 437730 439730 440728
 0.01 443127 443125 444123 443120 441119 439118 438119 437119
      436121 435121 434123 433123 432126 431128 431130 431131
      433132 435133 436133 438133 439132 440131 441130 442129
      443127
 0.01 412708 409690 405677 400662 396659 392660 388666 387672
      387680 389688 393704 390709 389716 392723 396726 402726
      404724 405721 406714 407711 409712 412708
 0.01 289787 288777 282767 275761 271761 267762 263766 262769
      262775 258779 253785 249790 243802 239809 238816 240823
      237830 232845 229851 228858 225866 225870 227874 233877
      235879 239878 244872 247867 251862 254855 255845 257838
      259832 260828 258827 255824 254819 251814 255808 259804
      263802 267801 273803 279800 283796 289787
 0.01 283972 283968 281966 279962 272953 267941 263937 257937
      253940 250945 248951 247958 248972 250978 253984 257988
      261986 272983 275982 277981 281976 283972
 0.01 261019 261014 260010 256006 255003 252000 249997 247000
      247004 250008 252012 254016 257018 261019 261019
 0.25 518183 519172 517163 513158 508155 504152 500146 493137
      488132 484128 471123 466125 461126 456125 452127 448134
      448141 445145 438144 434148 432155 436165 440166 443169
      446175 441189 441206 438209 432210 426208 421202 419204
      420207 420210 420214 416216 412216 409214 405211 399208
      395206 391206 393209 395214 399220 386232 385239 387246
      394256 397261 400267 403271 409275 417275 422274 428272
      432273 435275 438276 443275 451269 461260 469253 473251
      480252 484250 488246 490244 492240 497237 500232 501227
      502222 503212 501207 500203 500198 503194 513192 516186
      518183
 0.25 517939 517936 517934 517931 517929 517928 515926 515929
      515931 515934 514936 514939 514942 515944 515945 516944
      516942 517940 517939
 0.25 481226 481224 479226 480227 481226
 0.25 492194 491188 487185 483187 481185 477181 473181 467186
      459190 456191 453195 451203 454206 457204 461204 466205
      470204 473202 480200 488198 492194
 0.25 504156 504154 503155 504157 504156
 0.25 454105 455100 453098 451096 448097 446104 441104 434102
      430106 430110 433111 438110 443111 447111 450113 451110
      454105
 0.25 451814 451809 451804 450799 449797 447794 445791 443793
      443798 443803 444807 444812 447814 449816 451814
 0.25 438763 438758 437753 435751 433751 429752 428755 428758
      429761 429764 431769 432771 434775 435777 437775 438770
      438765 438763
 0.25 397679 396680 397680 397679
 0.25 428190 429187 429185 429184 427183 425184 423186 424188
      424190 426191 426193 428192 428190
 0.25 423796 424794 424791 424789 422788 421789 421790 420792
      419793 419794 418797 418798 418799 418802 418804 419804
      420802 421801 422799 423796 423796
 0.25 272775 272772 272770 270769 269769 268769 267771 267772
      267773 268775 268777 267779 268781 270780 270779 271777
      271776 272775
 0.25 264790 263786 258787 255789 253792 249796 248799 246803
      247807 250806 254803 257800 261797 263794 264790
 0.25 232864 235866 240866 244863 249854 248847 245841 244833
      242832 240834 237840 235844 233850 232856 232864
 0.50 512186 514179 513174 509167 504163 497161 493158 491154
      488152 486148 485151 482152 476149 474144 477142 484142
      488148 494152 497154 498154 498150 497146 494144 485133
      471128 468135 465135 461133 458132 455134 453137 453141
      452146 451149 449151 445150 438148 436150 435156 439162
      445166 448174 449177 448181 446188 448191 451190 464184
      468179 470175 473174 498175 503178 506184 509188 512186
 0.50 498229 499215 498210 496206 489203 482202 468207 461205
      459206 455209 448210 440211 434213 426213 420220 418223
      414222 400226 396227 392230 391234 390239 392247 397253
      407267 410269 415270 421269 429265 436263 442268 449264
      455259 460254 465249 471246 481247 484246 485242 486235
      485231 483232 482229 477226 472225 474222 477222 481223
      483227 489227 494232 498229
 0.50 446802 447800 446798 445800 446802 446802
 0.50 436763 436761 434760 432760 432761 432764 432766 432768
      433770 433771 435772 435770 436768 436765 436764 436763
 0.50 408218 407216 406215 405214 403213 402213 400213 399213
      400215 400216 401216 403217 404219 406219 408218
 0.50 257795 258793 256792 255793 254793 253794 252796 251797
      251798 250800 249802 250803 252802 254800 255798 256797
      257796 257795
 0.50 245853 245851 243847 242845 241841 239841 238844 237846
      236849 235852 235856 234858 235860 238861 241859 243857
      244855 245853
 1.00 492219 493217 493213 490210 485206 479206 473208 470209
      466209 459209 457212 454212 448213 440213 435216 429217
      426218 424220 423224 425228 423229 419229 411227 406230
      398230 396232 395238 395242 397245 403249 408254 412261
      417264 422262 432251 438248 441250 443253 448255 451254
      456250 466242 469240 472241 478243 480243 482240 481234
      479230 474229 469231 466226 471222 476220 483221 489221
      492219
 1.00 486164 484157 478157 474154 470150 467144 461142 458143
      458145 458153 461157 464162 466165 469167 473163 476162
      479164 486164
 1.00 476136 475136 474136 475137 476136
 1.00 463178 463176 463175 461174 459175 458176 456176 455176
      454179 453181 454181 455183 457183 459182 460181 462181
      462180 463178
 1.00 446157 444157 443156 441155 439155 439156 441157 442157
      444157 446158 446157
 1.50 486218 487213 486210 481208 476208 472211 467210 463212
      454213 444215 439216 436218 426221 426224 430227 436228
      441227 445228 448231 439236 438238 438241 443244 447246
      452245 459242 465239 467236 466232 464230 462231 460233
      457232 452230 454226 458226 461227 464226 467223 475218
      483219 486218
 1.50 479238 479236 478233 477233 476232 474232 473234 473236
      474238 475239 477240 479239 479238
 1.50 470160 471158 470157 469155 469154 467153 466154 466157
      467157 468158 469160 470160 470160
 1.50 428250 430244 430240 428236 425233 417231 412230 410231
      404235 398236 398240 400243 406243 412249 416255 419257
      421257 426252 428250
 2.00 482216 482214 482211 481211 480211 479211 477212 476212
      475213 473214 473215 475216 477216 478216 480216 482216
      482216
 2.00 471218 472216 471214 469212 463215 456215 449216 442217
      439218 437221 442225 449227 453225 457224 461225 463224
      465221 469220 471218
 2.00 465237 466234 464232 462233 462234 461235 462237 463238
      465237 465237
 2.00 461238 460235 457233 454233 452234 448234 446235 444238
      444240 445241 449242 450242 454241 456241 459240 461238
 2.00 435223 434222 432221 431221 429221 427222 427223 428224
      430225 432225 433224 434224 435223
 2.00 427247 428244 428240 427236 422234 417232 411233 409235
      409239 412243 415246 419249 421250 425249 427247
 3.00 447221 446221 447221 447221
 3.00 463221 462220 461219 459219 457218 456217 454216 452218
      451220 452221 453221 455222 457222 459222 460223 462222
      463221
 3.00 453238 451236 450235 448235 447236 448237 449239 451238
      453238 453238
 3.00 468217 468216 468217 468217
 3.00 426244 427242 426240 426239 425238 423237 421236 419236
      418235 416235 414235 413236 413238 414239 415241 417242
      418243 420244 421245 421246 423246 424246 425245 426244
 4.00 424244 425242 424240 423239 421239 419239 417238 416239
      417240 419240 420242 421243 422244 424244 424244
 5.00 423241 422240 421241 422241 423241

$$





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