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Quantitative Precipitation Forecast (QPF) Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1900Z Dec 20, 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
200 PM EST SAT DEC 20 2014


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


DAY 1...

06Z UPDATE...
ONLY MINOR CHANGES WERE MADE TO PRELIM GUIDANCE BASED MAINLY ON
SATL/RADAR TRENDS.

...PAC NW/NRN INTERMOUNTAIN REGION...

A POWERFUL 150+ KT UPPER LEVEL JET WILL TAKE AIM AT THE PAC NW
COAST THIS PERIOD AND WITH IT WILL COME A SIGNIFICANT HEAVY TO
POTENTIALLY EXCESSIVE RAINFALL EVENT FOR MUCH OF THE COASTAL
RANGES AND CASCADES. MODELS CONTINUE TO HAVE HAD A GOOD HANDLE ON
THIS SYSTEM FOR THE PAST SEVERAL RUNS... AND CONTINUE TO SHOW
RATHER GOOD MASS FIELD AGREEMENT. THE LATEST SATELLITE IR/WV LOOPS
SHOW AN ELONGATED MOISTURE FETCH (AXIS OF ANOMALOUS PRECIPITABLE
WATER VALUES) EMANATING FROM THE SUBTROPICS BEING RAPIDLY DIRECTED
INTO COASTAL AREAS OF WA INTO NRN CA. THE ANOMALOUSLY HIGH
MOISTURE TRANSPORT (3-4 STANDARD DEVIATIONS ABOVE NORMAL) WILL
CONTINUE TO FOCUS ACROSS THE PAC NW COAST... ESPECIALLY OVER
OREGON WHERE THE AXIS OF MAX PWATS (1.25 INCHES ALONG THE OR
COAST) WILL REMAIN FOCUSED. THE DEEP-LAYERED AND VERY STRONG
WESTERLY FLOW WITH 850 MB WINDS INCREASING TO 40-50 KTS WILL LEAD
TO VERY STRONG OROGRAPHIC LIFT THROUGH MUCH OF THE COASTAL RANGES
INTO THE CASCADES. WPC CONTINUED TO LEAN HEAVILY TOWARD THE HIGHER
RESOLUTION GUIDANCE AND CONTINUITY TO SMOOTH OUT SMALL MESOSCALE
DIFFERENCES WHILE MAINTAINING BETTER OROGRAPHIC DETAIL. SNOW
LEVELS WILL CONTINUE TO RISE WITH THE INCREASED PACIFIC ONSHORE
FLOW/WAA AND THE COMBINATION OF EXPECTED VERY HEAVY RAINFALL AND
SNOW MELT WILL LIKELY LEAD TO RUNOFF ISSUES OVER LOWER ELEVATIONS
OF THE CASCADES AS WELL AS OVER THE COASTAL RANGES. 30 HOUR
AREAL-AVERAGE RAINFALL AMOUNTS -- FROM 18Z SAT THROUGH 00Z MON --
ARE EXPECTED TO RANGE BETWEEN 3-5 INCHES ALONG THE
OROGRAPHICALLY-FAVORED COASTAL RANGES AND FROM 4-8 INCHES ACROSS
THE OR CASCADES... WITH HIGHER AMOUNTS EXPECTED (LOCALLY OVER 10
INCHES) PER THE HIGHER RESOLUTION GUIDANCE. THE LATEST SSEO MEAN
40 KM NEIGHBORHOOD PROBABILITIES OF 3-6 HOURLY QPF EXCEEDING 3-6
HOURLY FFG TOP OUT OVER 70% OVER THE OR AND SOUTHERN WA CASCADES.

FARTHER EAST...EXPECT MOIST DEEP-LAYERED WESTERLY FLOW TO BRING
SIGNIFICANT QPF AMOUNTS EWD INTO THE NRN INTERMOUNTAIN REGION WITH
SIGNIFICANT SNOWS PSBL OVER THE HIGHER ELEVATIONS.  MODEL QPFS
WERE ALSO REASONABLY SIMILAR OVER THESE LOCATIONS... BUT AGAIN
LEANED TOWARD THE HIGHER RESOLUTION GUIDANCE FOR BETTER TERRAIN
DETAILS. REFER TO THE LATEST QPFHSD FOR DETAILS ON THE WINTER
WEATHER POTENTIAL.

...SOUTHEAST U.S....

GENERALLY LIGHT RAINFALL AMOUNTS ARE EXPECTED ACROSS THE SOUTHEAST
DURING DAY 1 GIVEN A PERSISTENT (ALBEIT WEAK) OVERRUNNING PATTERN
AS WEAK SOUTHERN STREAM VORT LOBES ALLOW FOR PERIODIC WAVES OF LOW
PRESSURE ALONG THE SURFACE STATIONARY FRONT. AREAL-AVERAGE TOTALS
ARE EXPECTED TO RANGE BETWEEN .10 AND .25 INCH...WITH HIGHER
AMOUNTS EXPECTED OVER THE EASTERN GOMEX AND OVER THE ATLC GULF
STREAM GIVEN THE SLIGHTLY MORE FAVORABLE THERMODYNAMIC PROFILE
(HIGHER MUCAPES...CLOSER TO 500 J/KG).

HURLEY

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


24HR QP VT 22/00Z
 0.01 497323 494311 491307 490301 489294 488287 483274 481268
      478263 471254 468253 466254 463261 460266 456269 450279
      443284 437285 434284 433281 431267 427263 422263 417261
      414256 410253 403251 391247 378243 376237 373234 368230
      366226 364223 364220 368217 377214 381211 381205 380199
      384196 395198 401201 404203 407201 415196 416193 419194
      424196 428197 427194 423190 419187 414187 409187 402186
      393181 389173 394160 395156 393150 390145 389141 392140
      393135 392130 390128 381124 381117 384111 388107 398101
      402098 402093 398093 392092 388089 384086 379085 374082
      372078 372073 374068 377064 380060 390053 399048 419053
      424054 427058 423073 417083 418086 421086 424084 426086
      434090 439089 445090 451091 456095 463097 465096 464092
      461087 459084 455084 448084 444081 441077 438075 433071
      435069 438067 443064 443060 442057 440050 437045 436038
      439036 441034 441030 441025 445021 449017 453015 458013
      462013 474014 485020 493028 498038 504047 508050 512055
      521062 528068 531074 532080 535085 537091 543103 556128
 0.01 545185 545180 544174 543168 541162 540157 538153 534144
      524129 514113 506107 501114 497115 492115 490116 490119
      492122 497131 499138 505143 512149 523163 527173 531181
      535190 539193 542197
 0.01 507929 507919 507911 505903 502896 499893 492894 489893
      488884 485881 482880 479886 478894 474899 472900 470904
      469906 467905 465905 464900 466893 467887 469871 469863
      467856 465851 463849 460849 456849 455852 451855 448860
      446867 444873 442878 440885 436890 426894 425896 421898
      418896 415896 411898 406899 401903 399908 400917 401922
      409931 412934 414936 417936 419934 423933 430933 437927
      444925 450923 460927 464930 467937 475944 478948 480951
      478954 474957 470962 469968 471972 480978 488987 495995
      498998 500998 501993 490971 496970 499965 500956 502952
      506940 506931 507929
 0.01 494133 491129 489124 487119 484116 481114 478111 475109
      473111 472116 472118 474119 478121 482123 485126 488129
      491133 494133
 0.01 466199 466197 466195 464194 462194 461194 460195 459197
      460199 462199 463200 465200 466199
 0.01 444671 442668 438669 433674 427681 425684 421683 413683
      411686 409690 406696 404703 404709 402712 397719 396721
      396726 399726 403725 407724 410721 412719 417719 424718
      432716 435715 437712 433708 432703 433699 436693 439685
      443677 444671
 0.01 231969 235984 238989 246992 252992 257988 268981 273977
      277972 279964 277959 277955 278951 281944 285931 289916
      292899 296885 299878 301872 310861 320851 325846 327841
      324833 323830 322825 322815 324808 326800 329794 337782
      342769 346755 348747 348743 348738 351722 350715 347707
      344701 340696 337694 333694 326694 322695 320697 314701
      309705 309713 307729 304735 303745 305780 305785 302789
      299794 298797 296800 292806 294814 292820 288825 282829
      277833 271835 254835 247837 242841 232849 221857 224877
      234883 240884 245882 256878 261875 265876 266878 265886
      264892 259903 255913 253919 250925 246935 240946 235955
      231965
 0.25 524260 516246 511224 511219 514217 517215 519210 522199
      523189 523176 522171 519169 514163 507155 501151 495145
      490137 485131 478127 471123 464117 466113 466107 461101
      456100 454097 451094 447094 443095 440093 432093 429091
      427090 425091 425101 418104 414108 411105 409102 406103
      403106 399108 392111 390114 390116 391118 396123 402130
      405130 408128 414129 415132 413141 408147 403153 404158
      407161 413167 422169 424172 429175 433177 435178 435181
      433184 431185 429184 425186 426187 434187 436196 436202
      435206 430206 426204 423200 420199 416202 416206 414209
      411211 408211 403210 395206 391204 390205 393211 398218
      402221 402223 400225 392226 388226 385228 383230 384234
      389238 396244 405248 424251 439250 455247 462245 469245
      477249 483255 492272 499287 502290 503289 508283 511278
      516281
 0.25 499250 498246 496241 494238 491233 489229 486228 483229
      483234 486234 489237 492240 495244 498248 499250
 0.25 489190 488190 487189 486187 485187 484189 483189 482190
      480190 481191 483193 485193 486193 488192 489190
 0.25 479228 480226 479225 477224 475224 475227 477228 478228
      479228
 0.25 478192 480190 479187 476184 471183 464186 458189 454195
      451198 450202 451205 456206 460202 466205 470200 476196
      478192
 0.25 460121 461116 459112 457114 455119 448121 445122 441121
      437121 434123 430128 429133 430137 432137 434134 439129
      441126 446126 450128 453126 458122 460121
 0.25 450078 449077 448076 447075 446074 445073 445072 443071
      441071 440071 439072 440072 441072 443073 444075 446076
      447077 448078 449078 450078
 0.25 421178 422176 422174 421171 420171 418173 418175 417175
      417176 418177 419179 421179 421178
 0.25 415076 416066 416062 414061 407059 400059 396062 392066
      390068 390073 393078 399079 402076 410076 415076
 0.25 342753 341741 337733 333726 330723 327722 322722 317724
      314727 313732 312740 312749 313761 313773 312782 310790
      309799 308804 309807 312809 313807 316804 321798 330785
      337771 340763 342754 342753
 0.25 309820 306821 302825 295831 287834 280840 277843 270845
      261846 248846 239850 235852 232856 230861 233866 236868
      243869 253866 264863 271862 274863 275865 277870 279874
      283878 285878 288877 292874 294870 298859 304838 309820
 0.25 281908 280901 278896 273900 269905 263917 258929 254943
      252950 251958 251962 253964 259968 266965 268963 270960
      274947 277933 280916 281908
 0.50 523264 517257 514248 511238 507227 503219 499209 494201
      490199 486199 471202 468206 465207 461205 459205 457207
      454210 450210 447209 444205 445198 449195 454191 458188
      462186 466180 469175 472174 481171 489176 494176 497175
      498179 499185 505194 511200 514197 515194 516186 516181
      513175 510170 507167 503165 495164 493161 490157 492147
      488139 486134 483131 480129 476128 470125 468127 464129
      459130 452131 444134 438139 432143 427142 425139 424137
      421137 418140 413150 406154 409155 411159 413163 418164
      423162 426165 427171 435171 440172 442175 438186 443206
      435209 432211 428209 424207 425210 425214 423217 420220
      418227 415226 414221 414218 412217 408220 407225 404228
      395229 392231 391236 397242 405245 414246 424248 441246
      455243 463240 468241 472242 477245 482246 485245 487251
      495269 499277 501280 505281 506273 506270 509269 513273
      518277
 0.50 502254 500245 497239 493232 491228 487226 481223 477222
      474224 473227 476229 480231 482234 484238 487239 491242
      493246 497252 501256 502254
 0.50 486151 485149 485146 484146 483146 481146 480146 478146
      476146 475146 474146 474148 474149 476150 478150 479150
      481151 482152 484152 486151 486151
 0.50 455103 452097 446097 431094 429093 427095 428098 427103
      421104 417110 414110 410108 407105 402110 396111 394113
      394117 400120 407122 414123 418123 422125 426125 429123
      433119 438117 446117 450112 455103
 0.50 404217 403215 402214 402213 400212 398211 397212 397215
      398215 399217 401217 403217 404217
 0.50 414073 413072 413071 412068 410066 408066 407066 405065
      403066 402067 402069 403070 405071 406072 408073 410073
      411073 413074 414073
 0.50 337756 336748 335743 331738 328735 324733 319733 317737
      316742 315748 315755 316768 316782 316788 317792 319792
      325786 331776 335767 337756
 0.50 292843 290841 286842 282844 279846 278849 280852 282854
      285858 284864 285866 288866 290862 291856 291851 292845
      292843
 0.50 274927 274919 273916 270916 267921 264926 262931 260937
      259943 259951 261953 265952 268947 270943 272937 274929
      274927
 0.50 250851 249851 247851 245851 244851 245852 247852 249851
      250851
 1.00 500266 500264 499261 498261 498259 496257 494259 495262
      495263 497265 498267 500266
 1.00 495218 496213 494210 491205 484203 478203 476205 473204
      471208 468209 462209 458212 446214 439212 435215 429217
      424220 422221 421224 426228 431232 430235 427236 415231
      410230 405235 402237 398236 396238 399240 404240 411243
      416244 423246 447242 458240 463237 466237 467234 470225
      474221 479220 486222 492221 495218
 1.00 481242 481239 481237 481236 479233 478232 476231 475231
      473231 471232 469233 470235 470236 472238 473239 473240
      475241 476242 478242 480242 481242
 1.00 484161 483158 482157 481158 480159 478160 480162 481163
      483163 484161
 1.00 477159 468146 461141 457139 455140 449146 446148 444147
      439145 435146 432148 429151 430157 432161 435164 440165
      443166 445171 447177 445181 441184 441188 444190 452189
      458185 464180 463173 460172 457169 457164 460163 462164
      466167 470169 474164 477159
 1.00 450232 451230 451229 450229 449230 448231 448232 450232
      450232
 1.00 444111 442106 439104 434102 433104 428105 424105 423109
      425112 429114 433113 436112 442111 444111
 1.00 424117 425115 424113 422114 421114 420114 419114 417114
      415115 413115 412115 411115 410116 409117 410117 411118
      413118 413117 415118 417118 418118 420118 422118 424117
      424117
 1.00 418161 418160 416159 415160 416161 417161 418161
 1.50 488218 490213 489210 487207 484206 480204 478205 473206
      471211 469211 462211 458214 451213 446214 439214 433217
      429218 424221 423224 426226 431229 434232 435235 432235
      430237 425237 419234 413233 410235 409239 416242 423245
      427245 429243 441242 451240 457239 460237 460235 458232
      454232 452233 439231 444229 449227 453225 461227 471222
      474219 480218 488218
 1.50 480239 479236 479235 478233 476232 474233 473234 473237
      474237 475239 477240 478240 480239
 1.50 469162 469157 468152 464146 460144 457145 453153 448156
      443152 441149 436148 432152 432156 434160 438162 442162
      446163 448168 449176 449180 446182 443184 442187 449187
      457185 462181 463177 461174 457173 455171 453167 454163
      458157 462158 465160 467163 469162
 2.00 486212 485210 482207 476207 473209 471212 467212 461213
      460215 456215 453214 449215 444215 439215 434218 428219
      423222 425225 427226 435230 447227 452224 458224 470220
      476218 481216 486212
 2.00 478238 478235 477235 476235 477238 478238
 2.00 458237 457234 455233 451235 448234 443235 439236 435237
      432236 431239 433240 438241 442240 446239 449239 454238
      458237
 2.00 461180 461176 459175 458175 455174 453171 451170 449171
      449174 451177 452180 453183 455184 457184 459182 461180
 2.00 449185 449182 448182 447184 448186 449185
 2.00 441156 441155 441154 440151 438150 437150 436151 435152
      434154 434155 435157 435158 437158 439158 441157 441156
 2.00 428242 428241 426239 424238 423238 421237 420236 418236
      416235 414235 413236 412238 414240 415241 417241 419242
      420243 422243 424244 425244 427243 428242
 3.00 481211 481210 479210 477209 476209 475209 474210 473211
      472214 473215 475215 477215 479214 480213 481212 481211
 3.00 470218 470216 469215 468215 467214 465214 466217 468219
      469219 470218
 3.00 460220 456216 453215 451216 445216 438216 435218 429220
      424222 427224 430225 436225 442226 448225 452223 457220
      460220
 3.00 424241 422240 421240 420240 421240 422241 424241
 4.00 455219 454216 452216 451217 452219 454220 455219
 4.00 449222 450220 450217 449216 447216 445217 444217 442216
      440216 439216 438217 437218 436219 434220 433220 434222
      436222 438222 439222 441223 443224 444224 446224 447224
      448223 449222
 4.00 433222 433220 431220 429220 428221 427221 425222 425223
      427223 429223 430224 432223 433222
 5.00 448219 447218 445217 444217 442216 440216 440217 439219
      440219 441220 443221 445221 446221 447220 448219
 6.00 445218 443218 442217 441217 442219 443218 445218 445218