Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 201900
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
159 PM EST MON NOV 20 2017


PRELIM DAY 1 QPF DISCUSSION
VALID NOV 21/0000 UTC THRU NOV 22/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

NORTHWEST CALIFORNIA INTO THE PACIFIC NORTHWEST

IN THE WAKE OF THE CLOSED LOW SHEARING SOUTHEASTWARD MONDAY
NIGHT/EARLY TUESDAY FROM THE PACIFIC NORTHWEST INTO THE NORTHERN
ROCKIES---MID TO UPPER LEVEL RIDGING WILL BE BUILDING NORTHWARD
FROM NORTHERN CALIFORNIA INTO THE PACIFIC NORTHWEST/NORTHERN
ROCKIES REGION.  THIS WILL RESULT IN STRENGTHENING SOUTH
SOUTHWESTERLY LOW LEVEL FLOW FROM NORTHERN CALIFORNIA INTO THE
PACIFIC NORTHWEST AND A NORTHWARD SURGE OF MUCH ABOVE AVERAGE PW
VALUES INTO THE PACIFIC NORTHWEST---NORTHERN GREAT BASIN AND
NORTHERN ROCKIES.  OVERALL---THERE IS GOOD MODEL AGREEMENT WITH
THIS EVOLUTION AND THE PRECIPITATION DISTRIBUTIONS AND AMOUNTS DAY
1.  WIDESPREAD MODERATE TO HEAVY PRECIP TOTALS LIKELY FROM THE
NORTHWEST CALIFORNIA COAST RANGE---THROUGH THE OREGON AND
WASHINGTON CASCADES AND WESTWARD TO THE OREGON AND WASHINGTON
COAST RANGES AND OLYMPIC RANGES.  WITH THE LOW LEVEL FLOW HAVING A
SIGNIFICANT TERRAIN PARALLEL COMPONENT---VERY HEAVY TOTALS NOT
EXPECTED.  MODEL CONSENSUS FOR THE GREATEST OROGRAPHIC COMPONENT
TO THE LOW LEVEL FLOW WILL BE OVER FAR SOUTHWEST OREGON/FAR
NORTHWEST CALIFORNIA AND INTO THE OLYMPIC PENINSULA.  IN BOTH OF
THESE AREAS---MAX PRECIP TOTALS IN EXCESS OF 5 INCHES
POSSIBLE---WITH AREAL AVERAGE 1-2"+ AMOUNTS ELSEWHERE FROM THE
CASCADES WESTWARD TO THE COAST RANGES.

INLAND OVER THE NORTHERN GREAT BASIN AND NORTHERN ROCKIES

THE AREA OF PRECIP ASSOCIATED WITH THE SOUTHEASTWARD SHEARING
CLOSED LOW EARLY DAY 1 WILL DECREASING IN SIZE AND INTENSITY
RAPIDLY EARLY IN THE DAY 1 TIME PERIOD AS THE CLOSED LOW WEAKENS.
LIGHT TO LOCALLY MODERATE PRECIP TOTALS POSSIBLE EARLY DAY 1
ACROSS THE NORTHERN ROCKIES FROM NORTHERN WY INTO CENTRAL TO
NORTHERN ID AND WESTERN MT.  ADDITIONAL LIGHT TO MODERATE PRECIP
LIKELY TO SPREAD BACK INTO THE NORTHERN GREAT BASIN AND NORTHERN
ROCKIES LATE DAY 1 FROM FAR NORTHEAST OREGON---EASTERN WASHINGTON
INTO CENTRAL TO NORTHERN ID NORTHWEST MT

UPPER GREAT LAKES

STRONG HEIGHT FALLS WILL BE DIVING SOUTHEASTWARD FROM SOUTHERN
MANITOBA---ACROSS PORTIONS OF THE NORTHERN PLAINS---UPPER MS
VALLEY AND INTO THE GREAT LAKES.  THE CORE OF THE HEIGHT FALLS AND
THE TRACK OF THE ASSOCIATED SURFACE LOW WILL KEEP THE LARGE SCALE
OVERRUNNING PRECIP NORTH OF THE GREAT LAKES ACROSS CENTRAL
ONTARIO.  IN THE WAKE OF THE TRAILING COLD FRONT SWEEPING
SOUTHEAST THROUGH THE GREAT LAKES LATE TONIGHT INTO TUESDAY---POST
FRONTAL NORTHWESTERLY FLOW WILL SUPPORT INCREASING LAKE EFFECT
SNOW SHOWERS OFF OF LAKES SUPERIOR AND MICHIGAN WITH LIGHT TO
LOCALLY MODERATE TOTALS POSSIBLE FROM THE U.P. OF MI INTO THE
NORTHERN L.P.

HEIGHT FALL MOVING OFF THE SOUTH TX COAST EARLY DAY 1 AND
ADDITIONAL UPSTREAM HEIGHT FALLS DIVING SOUTHEAST INTO THE
SOUTHERN PLAINS LATER DAY 1 WILL HELP AMPLIFY THE SOUTHERN STREAM
TROF OVER THE GULF OF MEXICO THIS PERIOD.  PRECIP DOWNSTREAM OF
THIS TROF---INITIALLY CONFINED TO THE EASTERLY LOW LEVEL FLOW MAX
IN THE VICINITY OF THE OLD FRONT OVER SOUTH FLORIDA---WILL BE
LIFTING MORE TO THE NORTH WITH TIME AS THE LOW LEVEL FLOW VEERS TO
A SOUTHERLY DIRECTION AHEAD OF THE AMPLIFYING SOUTHERN STREAM
TROF.  THIS WILL SUPPORT POTENTIAL FOR PRECIP EXPANDING NORTHWARD
ALONG THE EAST COAST OF FLORIDA AND TOWARD THE SOUTHEAST COAST
WHERE WELL DEFINED LOW LEVEL FRONTOGENESIS IS EXPECTED.  PRECIP IS
ALSO EXPECTED TO EXPAND NORTHWARD FROM THE EASTERN GULF OF MEXICO
TOWARD THE FL PANHANDLE. CONFIDENCE IS LOW WITH DETAILS OF THE
EXPANDING PRECIP OVER BOTH OF THESE AREAS.  WITH PW VALUES RISING
TO 1.0-1.5+ STANDARD DEVIATIONS ABOVE THE MEAN---LOCALLY MODERATE
TO HEAVY TOTALS POSSIBLE.

ORAVEC

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


24HR QP VT 22/00Z
 0.01 545771 545763 543757 539744 536730 534724 530721 524716
      517708 513706 507708 501716 498727 496734 492738 486745
      481754 474762 467769 458775 451782 438797 424810 416818
      410828 406837 400846 396869 398872 403871 405868 407863
      408857 411852 415839 422832 426829 431826 436820 442819
      446823 448828 446834 443845 441849 436852 429852 425855
      422858 420858 421863 426862 429862 432864 436866 440866
      446865 448865 450862 451860 454861 457865 460870 460877
      458888 456894 458899 462903 467905 469902 472897 476887
      478882 482877 486875 487878 487882 485893 475912 472937
      476942 477948 477956 479962 484962 487960 490957 492957
      492960 505980 508989 513001 518009 521012 526014 532015
      534014 535010 535005 536996 536975 536968 535965 535961
      535943 534923 533917 533909 533890 532872 530858 530849
      531841 533827 537813 539802 540791 543785 545771
 0.01 529223 531208 528193 523182 518174 511165 509162 508159
      507153 501143 497131 494120 489108 486095 483090 482085
      476074 474069 471063 466053 463047 460042 454035 449034
      445034 434018 424013 423019 425025 427029 432030 435033
      436036 435045 438055 440059 439063 436067 432071 434076
      438077 442080 447085 449091 446093 442089 435091 427083
      422084 421088 423093 424096 423099 420103 419105 419108
      417112 412112 410100 407099 405105 401111 397113 392114
      392117 402117 407119 413120 418124 419131 417137 413141
      410144 408150 404153 402158 401162 403165 405169 408173
      414177 421184 424189 425192 424196 420199 414198 411200
      411204 409206 406206 401203 391197 383192 379194 380200
      385209 392218 400224 392227 389226 387228 383230 381238
      383242 385249 387254 392263 399270 409277 413279 418283
      428287 433286 438283 441278 443271 446264 447261 450260
      459262 465264 468267 474269 479273 497285 501288 506287
      509283 512278 515271 517264 522250 529223
 0.01 454127 445123 441121 436121 429125 424134 423148 427156
      428161 430163 431159 430154 430147 432140 434137 438135
      441134 444136 447136 448133 454127
 0.01 443210 441207 439204 437201 436199 435196 433193 430195
      429199 430203 431205 433207 436210 437211 441212 443210
 0.01 448743 446739 442737 438737 435740 435746 437751 439756
      441761 443762 445756 446751 447746 448743
 0.01 436177 437175 437172 436170 434169 433167 431166 431168
      429170 429173 428175 428177 429180 431180 433180 434179
      435178 436177
 0.01 428061 429052 429047 428044 419036 414035 410038 408044
      408052 406053 403051 399052 397053 389061 388065 389068
      389073 391079 397082 403083 407082 409081 417074 422070
      426066 428061
 0.01 367806 361807 358805 354806 350806 347804 345800 345796
      346787 349780 355766 357760 354754 349751 343753 336758
      334760 330761 312763 304765 297768 285773 273780 267785
      263778 262775 258776 255778 254782 249793 244799 241804
      241809 241819 243824 243825 246823 248820 251819 257816
      263819 266826 260830 255835 246844 237852 234860 233868
      232875 235880 247877 254875 257869 264866 270865 280865
      286867 300870 304869 306868 310864 316859 320853 320850
      318849 312843 308839 308828 309825 312822 318819 321818
      325817 331821 329824 329827 332833 331835 332840 332850
      334852 336850 342847 345847 348844 351838 354830 357823
      367806
 0.01 310941 308936 302934 295931 293924 292916 289911 288900
      289891 286884 284883 280883 275886 271891 269897 269906
      271914 270919 273926 274932 275943 274951 269954 263957
      250960 237963 234964 232966 232974 233977 235980 238980
      242980 247980 253978 255977 260976 266975 272973 275972
      278970 298956 305949 309945 310941
 0.25 531790 530780 528771 525762 521758 513759 508762 504768
      501775 500781 495794 492797 492800 493808 496815 496821
      496827 497838 497848 498870 497878 497884 498888 500894
      501906 504913 507918 512918 515913 518905 519897 519876
      520855 521837 522827 523820 528804 530797 531790
 0.25 514256 515248 514242 511232 506223 502212 498202 495198
      492195 487193 485190 485180 483175 483168 481164 475156
      467152 464150 462150 461153 463155 471195 468200 464202
      460202 457206 455211 451214 442215 437215 433212 427210
      425213 422221 421228 416230 410225 407236 402245 410250
      415253 418256 421260 425262 429260 432257 437255 441255
      451255 460256 466258 471260 480266 494277 499280 503280
      506276 509270 514256
 0.25 489142 489139 487136 486134 485133 484133 483131 482130
      481129 480130 479131 479132 479134 479135 481136 482138
      484139 485141 487143 488143 489142
 0.25 465176 461174 458176 455172 454166 453162 451157 445150
      443147 439144 436148 436153 438158 440161 446169 447173
      451178 452179 450183 451187 455186 462182 465176
 0.25 453081 454078 453077 451076 451075 450074 449073 448072
      447070 445068 443067 441069 441070 442072 443073 443074
      444076 445077 446078 448080 449081 451081 453081 453081
 0.25 444111 443102 442098 438098 434094 428089 426091 430099
      428103 425104 422106 423110 422117 424120 426122 429120
      433116 440114 444111
 0.25 399213 399211 399209 399208 397206 396206 394205 392205
      390206 392208 392209 393210 395212 396213 398214 399213
 0.25 412071 412068 410067 408067 407066 405066 403067 403068
      405069 406070 408072 408073 409073 410072 412072 412071
 0.25 408058 407058 405057 404056 402055 400055 402058 404059
      405059 407059 408058
 0.25 327794 322789 314785 309782 305781 299782 292784 284789
      275791 267791 259790 256791 254796 252803 254805 259803
      264804 267805 274809 280814 285819 290819 292817 299813
      308811 313809 316806 322802 326796 327794
 0.25 296855 295849 292846 286841 283840 277840 270840 261842
      256844 252846 250850 251853 253856 258858 267858 278859
      287858 293859 296855
 0.50 510254 511246 509238 507233 505231 502225 500217 498211
      492205 487202 481202 476204 470208 465210 462209 459210
      455214 449216 442217 436217 430217 424221 423223 425226
      419232 416231 412235 411242 415247 420252 426254 432254
      437251 443250 456251 463252 470254 478258 484263 494271
      499275 502275 504273 506267 506260 510254
 0.50 517824 517815 515809 512806 507810 506814 504821 504830
      504839 503854 504867 506876 508882 510886 512879 514866
      514848 515834 517824
 0.50 498250 498249 497247 496245 496244 495242 494241 494239
      493238 493236 491237 492239 493240 493242 494243 495245
      496246 496247 497250 498250
 0.50 485233 486230 486228 485227 485225 484224 483223 481222
      479222 478222 476222 475222 476224 477224 478225 479226
      480228 480229 481231 482232 483234 485233 485233
 0.50 475224 474223 472223 470226 472226 474225 475224
 0.50 453173 451171 449172 449173 451174 453173
 0.50 437107 436102 436097 433094 429094 431097 433102 430105
      425105 425109 428112 431111 436109 437107
 0.50 316798 314794 310792 300792 292791 286793 281795 277795
      273795 269798 268800 271804 278808 282810 286812 295808
      304805 312802 316798
 0.50 289852 289851 288850 287848 286848 285847 283847 281847
      279848 278850 280851 282852 283853 285853 287853 289852
      289852
 0.50 277848 276848 274848 272847 270846 268846 267846 265846
      263846 261847 259848 261850 263850 265851 267851 269851
      271851 272851 274851 275851 276850 277848
 1.00 505242 504237 502233 499225 497217 495213 493211 485207
      478209 467215 460215 453218 451221 447221 442220 440222
      443224 447224 451223 454223 459225 463226 466224 471220
      478220 486222 489224 491227 494234 499240 503242 505242
 1.00 499266 498258 494249 491243 489239 486237 484240 482238
      479231 476228 473229 466231 453234 447236 440238 438239
      435242 438243 442242 450245 457246 465248 473250 481254
      486259 492264 495266 499266
 1.00 435225 436223 434221 433221 431221 430221 429223 428223
      429223 430225 432226 434226 435225
 1.00 428245 428240 426239 423237 421236 418234 415234 414236
      414238 415241 417244 420246 423247 426247 428245
 1.50 495259 494254 492250 488241 482239 479234 476230 472231
      469233 464233 460235 453237 454240 459242 467245 476246
      484250 489258 493260 495259
 1.50 498229 497224 495218 492216 489213 484210 480211 476212
      474217 478218 483219 486220 489219 491222 492225 495230
      498229
 1.50 462223 464221 464219 463217 461217 459217 457217 456218
      455218 455221 457222 458223 460224 462223 462223
 1.50 425244 425242 424240 423239 422238 421238 419237 418236
      416235 415236 415239 415240 416241 417242 418243 420244
      422244 424244 425244
 2.00 496226 496225 495223 494222 494223 495226 496226 496226
 2.00 486217 486215 485215 484213 482212 481212 479213 477215
      478216 480217 482217 483217 485218 486217
 2.00 481241 480239 479235 478233 474231 473232 471235 469236
      467235 465234 462236 463240 464242 466242 470241 473242
      476243 479244 481241
 2.00 462221 461219 459219 457219 457220 459221 460222 462221
 3.00 478238 478235 477235 476234 474234 474235 474237 475238
      477239 478238

$$




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