Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 100659
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
158 AM EST SAT DEC 10 2016


PRELIM DAY 1 QPF DISCUSSION
VALID DEC 10/1200 UTC THRU DEC 11/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...PACIFIC NORTHWEST/NORTHERN ROCKIES...

DEEP LAYER CYCLONIC FLOW WEST OF VANCOUVER ISLAND WILL SLOWLY
SHIFT EAST AND INTO THE PACIFIC NORTHWEST THROUGH SAT AND SAT
NIGHT WHICH WILL MAINTAIN DEEPER LAYER AND MOIST ONSHORE FLOW.
NUMEROUS SHOWERS ARE EXPECTED TO FOCUS OVER THE WA/OR COASTAL
RANGES AND INTO THE CASCADES...WITH SOME SPILLOVER MOISTURE
FOCUSING DOWNWIND INTO THE HIGHER TERRAIN OF THE NORTHERN ROCKIES.
SNOW LEVELS WILL BE RATHER LOW IN GENERAL ACROSS THE PACIFIC
NORTHWEST WHICH WILL FOCUS ADDITIONAL HEAVY SNOWFALL ACCUMULATIONS
THROUGH EARLY SUN. A MULTI-MODEL CONSENSUS WAS USED FOR QPF...WITH
ADDITIONAL WATER EQUIVALENTS OF AS MUCH AS 1 TO 1.5 INCHES
EXPECTED OVER THE HIGHER TERRAIN OF WESTERN WA/OR. LESSER AMOUNTS
CLOSER TO A 0.50 INCH CAN BE EXPECTED WELL INLAND ACROSS THE
NORTHERN ROCKIES. PLEASE SEE THE LATEST QPFHSD FOR MORE WINTER
WEATHER DETAILS.

...NORTHERN/CENTRAL CALIFORNIA INTO THE GREAT BASIN AND CENTRAL
ROCKIES...

A STRONG JET MAX AND ASSOCIATED SHORTWAVE WILL CROSS NORTHERN CA
EARLY ON SAT ALONG WITH A WAVE OF LOW PRESSURE BEFORE THEN
SHEARING INLAND ACROSS THE GREAT BASIN AND TOWARD THE CENTRAL
ROCKIES. THIS ENERGY WILL FOCUS AN ATMOSPHERIC RIVER OF PACIFIC
MOISTURE WITH SOME SUBTROPICAL CONNECTION INTO THE
NORTHERN/CENTRAL CA COASTAL RANGES AND ESPECIALLY THE NORTHERN AND
GRADUALLY CENTRAL SIERRA-NEVADA THROUGH THE DAY ON SAT. VERY HEAVY
OROGRAPHICALLY FOCUSED RAINS ARE EXPECTED FOR THE WEST-FACING
SIERRA-NEVADA FOOTHILLS WHERE AS MUCH AS 5 TO 8 INCHES OF RAIN IS
EXPECTED FOR THIS PERIOD. THE HEAVIEST RAINFALL SHOULD BE
GENERALLY BEFORE 00Z SUN WITH A STRONGLY ORTHOGONAL ORIENTATION OF
THE DEEP LAYER FLOW RELATIVE TO THE HIGHER TERRAIN AND ALSO A CORE
OF ENHANCED LOW TO MID LEVEL MOISTURE FLUX. THE DEEP WESTERLY
PACIFIC FETCH OF MOISTURE AND JET ENERGY THOUGH SHOULD MAINTAIN
THE THREAT FOR ADDITIONAL HEAVY RAINS LOCALLY THROUGH EARLY SUN.

FARTHER INLAND INTO THE GREAT BASIN AND THE CENTRAL ROCKIES...MUCH
ABOVE AVERAGE PW VALUES AND THE AFOREMENTIONED JET ENERGY WILL
DRIVE MODERATE TO HEAVY PRECIPITATION...WITH PORTIONS OF NORTHERN
NV AND ESPECIALLY THE WEST-FACING SLOPES OF THE WASATCH AND THE CO
HIGH COUNTRY SEEING THE HEAVIEST TOTALS WHICH INCLUDE SOME HEAVY
SNOWFALL. WPC QPF TENDED TO LEAN TOWARD A CONSENSUS OF THE HIGHER
RESOLUTION GUIDANCE.

...NORTHERN PLAINS/UPPER MIDWEST...

LARGE SCALE LIFT IS EXPECTED TO STRENGTHEN OVER THE NORTHERN
PLAINS ON SAT AND PUSH TOWARD THE UPPER MIDWEST BY LATE IN THE DAY
IN ASSOCIATION WITH STRENGTHENING ISENTROPIC LIFT NORTH OF A WEST
TO EAST ORIENTED FRONTAL ZONE THAT WILL BE STRENGTHENING AS LOW
PRESSURE DEVELOPS OVER THE CENTRAL PLAINS. THE MODELS SUGGEST A
RELATIVELY DEEP LAYER OF FRONTOGENETICAL FORCING TOO THAT WILL
HELP TO FOCUS STRIPE OF MODERATE TO HEAVY SNOWFALL FROM THE
DAKOTAS EAST-SOUTHEAST ACROSS THE UPPER MIDWEST AND DOWN TO THE
LOWER LAKES REGION THROUGH SAT NIGHT AND EARLY SUN. WPC QPF
GENERALLY LEANED TOWARD A MULTI-MODEL CONSENSUS WITH PERHAPS A BIT
MORE WEIGHTING TOWARD THE GFS...WITH WATER EQUIVALENTS OF AS MUCH
AS A 0.25 TO 0.50 INCH. THIS WILL SUPPORT THE HEAVIEST SNOW
FALLING FROM SOUTHERN MN/NORTHERN IA DOWN ACROSS SOUTHERN WI AND
NORTHERN IL THIS PERIOD. PLEASE SEE THE LATEST QPFHSD FOR
ADDITIONAL WINTER WEATHER INFORMATION.

...GREAT LAKES...

COLD CYCLONIC FLOW OVER THE WARMER GREAT LAKES WILL CONTINUE TO
SUPPORT SOME LAKE EFFECT SNOW FOR SAT BEFORE GRADUALLY WANING AS
THE LOW LEVEL FLOW WEAKENS. BY SAT NIGHT AND EARLY SUN...THE LOW
LEVEL FLOW WILL BEGIN TO VEER AS WARM ADVECTION ENSUES AHEAD OF AN
AREA OF LOW PRESSURE DEVELOPING OVER THE CENTRAL PLAINS. BROAD
WARM ADVECTION AND RESULTING ISENTROPIC LIFT IS EXPECTED TO ALLOW
SNOW TO DEVELOP AND BEGIN OVERSPREADING PORTIONS OF ESPECIALLY
LOWER MI BY SUN. PLEASE CONSULT THE LATEST QPFHSD FOR MORE WINTER
WEATHER DETAILS.

...SOUTHEAST FLORIDA INTO THE FL KEYS...

LOW LEVEL EAST TO NORTHEAST FLOW OFF THE ATLANTIC WITHIN A DEEPER
POOL OF MOISTURE FOCUSED ALONG AND NORTH OF A FRONTAL ZONE NEAR
THE FL KEYS WILL CONTINUE TO FAVOR SOME SHOWER ACTIVITY. THE MAIN
THREAT WILL BE TO THE IMMEDIATE COASTAL AREAS OF SOUTHEAST FL AND
THE UPPER KEYS WHERE LOW LEVEL CONVERGENCE WILL BE A BIT
STRONGER...BUT THE ONSHORE FLOW WILL EXTEND UP THE FL EAST COAST
AND SO SOME SHOWERS WILL BE POSSIBLE FARTHER NORTH AS WELL ALONG
THE FL ATLANTIC COAST. CANNOT RULE OUT SOME ISOLATED HEAVY RAINS
DOWN NEAR THE FL KEYS GIVEN THE MOISTURE THAT WILL BE IN
PLACE...BUT OVERALL THE AREAL AVERAGE TOTALS SHOULD BE FAIRLY
MODEST WITH THE HEAVIER RAINS REMAINING OFFSHORE.

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

ORRISON

24HR QP VT 11/12Z
 0.01 531197 531192 530186 528174 518159 515155 510153 508148
      504146 502141 501134 507126 508122 509116 508104 506094
      501085 499071 499063 498058 498051 497046 494033 490012
      486988 485973 483961 480950 479934 476924 476909 478905
      479901 480897 480890 482885 482878 483873 481867 479863
      477857 476849 477842 478839 477834 469831 465829 463825
      464821 462815 459803 457798 456793 454793 444782 440775
      439768 440763 441758 441751 439745 436745 431753 429750
      428750 424748 419747 417749 416755 418759 419771 416782
      405776 398783 393791 391796 393801 396810 396818 397825
      398829 401839 402851 403866 403876 403884 402889 403897
      405902 411906 413918 416928 417933 417938 416943 416948
      417956 419961 425981 427985 428990 429995 432999 435002
      439001 442007 444012 445018 445024 442033 441038 442043
      445053 446063 445067 443067 440069 436071 434074 437077
      442078 445082 447087 447091 441090 436090 433089 429087
      426083 424077 425069 427065 427058 412050 409041 408035
      407030 404028 401030 401036 399044 398047 395050 391059
      383061 380064 378066 375066 373070 372077 372085 372088
      374092 376098 379101 380098 390098 395094 399093 404094
      403101 400102 397101 395104 392108 388110 381115 378118
      375123 372130 372141 371145 374148 379156 384158 386162
      384168 383176 384182 387185 388188 383186 375182 365180
      360178 357180 354182 353184 354189 353197 348198 346198
      345200 347210 342219 341230 342240 345243 346249 351256
      359254 363252 366246 368243 371243 380247 388250 393252
      396253 398255 414255 433257 450256 457255 463257 468259
      476264 483270 490277 500285 502286 505283 511277 516270
      517258 516252 514246 512233 508223 506214 510202 514203
      517201 520202 521205 526205 531197
 0.01 484194 485189 482187 477182 473180 469180 467182 463185
      460188 457197 459204 463204 464206 467207 469205 472200
      478200 479197 482196 484194
 0.01 469073 468070 467065 467063 468058 464055 461055 459057
      458062 457067 458071 462072 463074 465075 467077 468075
      469073
 0.01 472912 472910 472907 470905 469907 469908 467908 465910
      466913 467914 469914 470914 472912
 0.01 464883 465876 463871 461866 459862 454864 454872 453877
      453884 455889 457893 459898 462903 463899 463895 463891
      465885 464883
 0.01 451833 450830 448829 445827 441825 439823 436821 434823
      436828 437835 440839 442841 444846 446847 447843 449840
      450835 451833
 0.01 435809 435804 435799 435794 433791 431790 429786 428791
      428795 428798 428803 428807 429812 430816 432819 434821
      435816 435811 435809
 0.01 339958 335955 327955 320956 312956 308956 306958 300959
      286962 285964 281962 279960 276960 269960 263961 247961
      240961 234963 231968 231971 233973 241974 246973 252975
      258973 263974 268974 276975 284974 288979 288983 291985
      291989 289993 287994 287998 291002 295000 297993 299985
      302980 306975 310975 312977 317973 328969 336965 339958
 0.01 301813 300810 297809 293807 283802 278800 272797 273792
      270787 265784 261782 254783 248785 236790 227797 225801
      224807 225823 223835 223843 226847 230850 233850 236848
      240845 242840 244835 245827 246822 248816 251811 254807
      259804 263803 265805 272804 276804 278805 284807 289810
      296813 301813
 0.25 504273 506250 507243 507237 506229 504224 500214 498210
      495207 492204 489203 484203 480205 473208 470210 465210
      460210 456212 448214 440215 433219 430221 427225 428232
      427235 425235 416236 414232 411228 411224 413216 415210
      417208 419204 418198 417193 417189 423182 426170 428159
      429152 429146 429138 430130 432123 434119 436117 440115
      447116 451113 449107 449103 452100 449097 443097 439095
      436096 428090 424088 425091 429100 426102 422103 415109
      413106 411101 409098 406098 404105 400105 385116 383120
      386125 394126 400130 404130 407133 406139 402141 398142
      396145 394149 393155 393163 392170 391174 392178 397184
      397191 394193 388192 383191 375185 370184 364183 362184
      360187 363192 366196 367200 369204 368209 362209 359210
      355214 355220 357225 361228 366229 377231 387238 395242
      399243 404243 411241 414239 417243 421247 426249 436250
      445250 454250 463250 473254 481259 489265 496271 501275
      504273
 0.25 487231 487230 486228 485227 484225 482224 481223 479223
      477222 476223 474224 475226 477227 477228 478228 480229
      481231 482232 483233 485233 486231 487231
 0.25 491170 490163 487156 485153 481152 476152 470148 465144
      460144 458146 456150 455155 453157 448154 441154 440157
      442159 446161 448164 449173 453177 456175 455170 455166
      456163 458162 462163 467168 469170 472171 477169 484171
      487171 491170
 0.25 486141 485140 485138 484137 482136 481135 479134 477134
      476134 475134 474134 472135 472136 472138 473140 475139
      476139 477139 479139 480140 481140 482140 483142 485142
      486141
 0.25 471016 470014 470013 470014 471016 471017 471016
 0.25 457818 457815 457813 456811 455811 454809 453809 452808
      450807 448808 447809 447810 446812 447813 448814 449815
      451816 453817 454818 454819 456818 457818
 0.25 454983 455966 453952 450938 446928 439904 437890 435883
      433877 426858 420860 417865 415868 414875 415890 417903
      419917 422931 425942 430953 434964 438974 440979 445983
      449984 454983
 0.25 424798 424796 424794 423791 423790 421790 420792 419794
      419797 419799 419802 419804 420806 421807 421806 422803
      423801 423799 424798
 0.25 415073 415068 417062 411060 408056 403055 399055 391062
      386064 384070 381074 376076 375080 378083 383076 391082
      398083 400081 409077 414075 415073
 0.25 256799 255795 251794 242796 235800 232804 231808 230818
      230828 231834 233834 238827 241819 245812 250805 256799
 0.50 502267 499257 498251 498245 500242 503237 503232 502225
      500219 497215 489209 482207 474209 470212 466213 458214
      440217 436221 435226 438236 437239 438243 442245 451246
      461246 465246 470248 479253 487259 494265 499267 502267
 0.50 492235 490229 489226 486223 479221 473221 469223 465228
      468231 473230 478230 481234 484236 487236 492235
 0.50 471160 471158 470156 469155 467153 465152 464152 462153
      463156 463157 465159 466160 468162 469162 471160
 0.50 460230 459229 458228 456228 454228 453228 452228 451229
      449229 449231 447231 448232 450233 452233 454232 455232
      457231 459230 460230
 0.50 446111 444103 442100 438099 427094 432102 429104 425104
      421104 421109 419112 414111 412109 410105 409102 406100
      405102 404107 400107 394111 389115 386118 386120 393120
      400123 409125 416128 422126 427120 431115 436112 443112
      446111
 0.50 420176 418166 421161 421158 421145 420141 416142 409145
      401148 397152 397159 396166 395170 396174 399178 408180
      412181 415179 420176
 0.50 409216 409210 409206 407204 403204 401202 398199 387194
      378189 373186 368185 364186 364191 369199 373204 376207
      380211 385214 396217 402219 406219 409216
 0.50 404196 406194 405192 404193 404196 404196
 0.50 414071 410065 406064 407060 406057 402057 400065 393064
      390065 387068 386071 388075 389078 392080 393076 394071
      396075 399078 402075 403072 408076 413073 414071
 0.50 377224 377221 375218 373216 371215 369215 365215 364213
      360212 358214 358219 360221 362223 366223 369225 372226
      375225 377224
 0.50 247802 246801 245802 244803 243804 241805 239807 238808
      237810 236812 238813 240812 241811 242810 242809 243807
      245805 246803 247802
 1.00 495259 494251 492245 489240 485239 483241 481239 480236
      476232 472234 471238 471241 478245 482247 487252 491256
      495259
 1.00 497229 498226 498224 497224 496222 494222 494223 494224
      494225 495228 495229 497229 497229
 1.00 488215 487213 486212 484211 482211 481211 480211 479211
      477212 476215 477216 478216 480216 482217 483217 485217
      487216 488215
 1.00 463223 463221 463218 461217 460218 459218 457219 456218
      454218 452220 453222 455223 457223 458224 460224 462224
      463223
 1.00 458237 457236 455235 454236 453236 451237 450237 451239
      453239 454239 456239 457239 458237 458237
 1.00 448224 448221 447220 445219 443220 443221 443222 443223
      444225 446225 448224
 1.00 417121 418116 415114 412113 410112 409108 407105 405108
      403110 400111 398112 397115 399115 403117 406118 410119
      411120 415122 417121
 1.00 404214 403210 401207 396201 389197 383193 376189 369187
      367188 367192 371198 376204 381208 385211 389213 396215
      400216 403215 404214
 1.00 410152 408151 407152 408154 410152 410152
 1.50 479241 479238 478235 477235 476234 475235 474236 474237
      475239 476240 477241 478241 479241
 1.50 415118 415116 413115 413117 413118 415118 415118
 1.50 401214 399206 396203 390199 385196 379193 374190 369190
      370195 374200 378204 382208 387211 394213 398214 401214
 2.00 399211 397206 393201 388198 382195 376192 372191 371192
      371195 375200 378203 383207 388210 394213 398213 399211
 3.00 396210 396205 394204 391202 389201 386198 384197 381196
      377194 374195 376198 378201 380203 381205 385207 386208
      390209 393211 396210
 4.00 395207 394206 392204 390203 389202 388201 387200 386199
      384199 382198 380198 380199 380201 381203 383204 383205
      385205 386206 388207 390208 391209 392209 393209 395207
 5.00 388203 387202 385201 384201 383202 383203 385204 387204
      388203

$$




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