Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS04 KWBC 201900
QPFPFD

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


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



...CENTRAL-NORTHERN CA INTO THE NORTHERN ROCKIES...

PER RECENT SATELLITE TPW LOOPS ALONG WITH SHORT-RANGE ESRL/ARDT
INTEGRATED WATER VAPOR TRANSPORT (IVT) FORECASTS...THE ELONGATED
ATMOSPHERIC RIVER EXTENDING FROM THE ITCZ INTO CENTRAL CA IS NEAR
PEAK WITH MAX OBSERVED PW VALUES PER GPS AROUND 1.25".
THERMODYNAMIC PROFILES ARE HIGHLIGHTED BY THE ANOMALOUS DEEP-LAYER
MOISTURE AVAILABILITY (PW ANOMALIES 3-3.5 STANDARD DEVIATIONS
ABOVE NORMAL)...ALONG WITH A ROBUST SOUTHWESTERLY LLJ (40-50+ KTS
AT 850 MB). MEANWHILE...DYNAMICAL FORCING WITHIN THE FAVORABLE
WARM CONVEYOR BELT (WCB) IS QUITE IMPRESSIVE...WITH THE
BROAD-SCALE UPPER DIFFLUENCE BOLSTERED SOMEWHAT BY THE STRENGTH OF
THE UPPER JET FORCING IN THE EXIT REGION (140+ KTS AT 250 MB).
ALL-IN-ALL...THE MECHANICS REMAIN IN PLAY FOR ADDITIONAL
SIGNIFICANT RAINFALL AND HIGHER ELEVATION SNOWS ACROSS
CENTRAL-NORTHERN CA...PARTICULARLY FROM THE BAY AREA AND NORTHERN
CENTRAL CA COAST THROUGH MUCH OF THE SACRAMENTO VALLEY AND INTO
THE CENTRAL-NORTHERN SIERRA THROUGH THIS EVENING. PER THE LATEST
SUITE OF AVAILABLE 12Z HIGH-RES CAM GUIDANCE...HOURLY RAINFALL
RATES ~0.50" WILL BE COMMON...WITH ISOLATED RATES OF 0.75-1.0+
INCH.

OVERALL...CONSIDERING THE MINIMAL MODEL DISCREPANCIES AT THIS
POINT IN TERMS OF MASS FIELDS...THE DAY 1 QPF ACROSS THE WEST WAS
A COMPILATION OF MULTIPLE MODEL SOURCES...INCLUDING THE PREVIOUS
FORECAST (CONTINUITY)...ALONG WITH SEVERAL HIGH-RES COMPONENTS
(INCLUDING THE HREF MEAN AND HIGH-RESOLUTION VERSION OF WPC`S
IN-HOUSE BIAS CORRECTED QPF). HIGHEST AREAL-AVERAGE TOTALS RANGED
FROM 3-5" ACROSS THE CENTRAL-NORTHERN SIERRA...WITH 2-3" ACROSS
THE EASTERN FOOTHILLS OF THE SACRAMENTO VALLEY AND NORTHERN SAN
JOAQUIN VALLEY. THERE IS SOLID ACCORD WITH THE HIGH-RES GUIDANCE
IN TERMS OF THE DEPICTION OF LOCALLY HIGHER AMOUNTS IN THE 6-9"
RANGE. FOR DETAILS ON WINTER WEATHER...SEE THE WPC WINTER WEATHER
DESK QPFHSD DISCUSSION.


...CENTRAL GULF COAST...LOWER MISSISSIPPI VALLEY...

THE INITIALLY FULL-LATITUDE UPPER TROUGH WILL BEGIN TO SPLIT
TOWARD THE END OF THE PERIOD (ON TUE)...WITH THE FLATTENING
NORTHERN STREAM WAVE PICKING UP MORE FORWARD SPEED WHILE THE
SLOWER...MORE VIGOROUS SOUTHERN STREAM TROUGH DEEPENS AND
EVENTUALLY CLOSES OFF AT MID LEVELS. UP TO THIS POINT...THE MODELS
HAVE STRUGGLED WITH THE FORWARD (EASTWARD) PROGRESSION OF THE
CONVECTION OUT AHEAD OF THE TROUGH...ALONG WITH THE NORTHERN
EXTENT OF THE HEAVIER RAINFALL. MANY OF THE MODELS... PARTICULARLY
THE HIGHER-RESOLUTION CAMS...NOW SHOW A BI-MODAL DISTRIBUTION WITH
THE HEAVIER QPF...WITH 2 STRIPES OF 1-2" AREAL-AVERAGE TOTALS
ALIGNED GENERALLY N-S. THE INITIAL AREA (FARTHER E) IS ALONG THE
MAX INSTABILITY AXIS WHERE OUTFLOW CONTRIBUTIONS WILL LIKELY ALLOW
THE CONVECTION TO RUN OUT AHEAD OF THE BEST DEEP-LAYER FORCING AND
AXIS OF HIGHEST PWS. WPC UTILIZED MORE OF THE HIGH-RES CAMS (ARW
IN PARTICULAR) WITH THIS INITIAL LINE...WHILE INCORPORATING A
GENERAL MULTI-MODEL BLEND OF THE GUIDANCE WITH THE AXIS FARTHER
WEST ACROSS EASTERN LA AND AR.

HURLEY

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

24HR QP VT 22/00Z
 0.01 520194 520189 519187 518182 514174 508164 505161 504157
      505153 502142 496133 491130 487126 484123 483119 483115
      479092 472084 469073 466060 465055 463052 458054 457062
      457069 458074 463083 465088 465095 466101 465104 463101
      457100 455095 451092 446091 440089 434089 426082 421087
      419092 418098 415102 412104 410101 407097 404102 401106
      397108 389114 394118 406122 408123 408127 408135 407140
      405142 402145 399152 395156 392162 387171 389176 392179
      394180 394184 390186 386187 381184 377181 370179 362177
      358179 356181 353186 354189 361197 364201 359201 354199
      350196 348191 348185 345180 343180 341187 339192 335198
      335203 338207 345215 349218 351223 354228 358231 361236
      360244 359246 361248 365250 370243 376249 380253 383258
      386268 388273 388279 388290 390296 395299 401302 404302
      412301 420301 426300 430297 436291 449280 454265 457261
      461258 466248 470247 474248 479250 483253 489255 495257
      501251 504247 507243 506229 505223 506218 507216 511212
      515206 520194
 0.01 528836 528827 526823 521815 519809 519804 517787 515738
      512726 507727 505729 485740 476746 465749 462749 459749
      454750 442752 431766 425777 422782 419785 413795 407801
      393818 385824 377828 372830 365830 356828 351826 346826
      334827 328829 323831 312836 295843 272851 266853 260856
      252861 244865 238872 233880 230887 232901 235910 239909
      239914 241918 239921 233928 231934 231938 232941 234945
      237948 246950 252952 257952 270952 277952 282950 296950
      306949 311951 316954 321954 324953 333950 342946 348944
      354943 357940 362938 367935 372934 393927 397926 403925
      413925 438924 452924 461925 474926 478927 484928 490928
      493929 499924 506916 513908 515904 516896 518884 518874
      518870 521869 525865 527863 527857 528845 528836
 0.01 475121 475119 474117 473118 473121 473122 475121
 0.01 449080 450078 450077 449075 448074 447073 446072 445070
      445069 443069 442067 441067 440069 439069 439072 440072
      441073 443074 444075 446076 447077 448078 449080 449080
 0.01 412073 412071 412068 412067 410066 409065 408065 407067
      406068 406070 406072 408073 410073 412073 412073
 0.01 403063 404060 404058 404056 402056 402058 403060 403063
      403063
 0.01 401074 399071 398071 397071 397073 397076 399076 401074
      401074
 0.01 375143 375141 376139 376137 376136 374134 374132 376130
      377128 375127 374130 374132 374134 374136 373138 374139
      375141 375143 375143
 0.25 507869 507864 504860 499851 491832 492826 495823 495822
      493821 487821 484821 481821 480818 479812 476811 475808
      476802 478798 485791 497776 496771 493773 487774 484772
      483768 481768 476769 473773 470778 468788 466793 463797
      453800 445807 443810 443817 446830 444844 446848 443851
      436857 433862 433866 433871 435873 428881 417894 414899
      415907 417910 421912 429911 439908 458903 468902 479901
      486901 491899 498893 503882 507869
 0.25 493168 491158 491154 489151 488149 486150 484153 481153
      478144 482143 485144 489148 489145 485136 482132 476131
      472131 471137 468142 464143 459145 457145 448138 443132
      442130 441126 444123 450114 453103 453097 450095 441094
      434092 430089 428087 424088 424093 425097 426100 424102
      421105 420111 417113 413115 415120 426136 428142 429148
      432157 437165 440169 443172 447175 448180 448185 451190
      453191 456187 461179 458169 459161 458157 460158 461161
      461165 464169 467171 469172 475174 477178 478182 481179
      484176 487174 492170 493168
 0.25 475219 477215 476210 473208 467209 463208 455206 453202
      451205 448207 445203 443208 437209 434210 431207 427204
      424200 422193 423187 423179 425173 425167 422169 416167
      412169 408182 401190 395192 389191 377185 372182 365180
      359181 358184 358187 365196 372205 374210 371211 368211
      348198 346198 345202 347207 354216 360224 364227 370231
      375232 382236 389245 395254 396260 397266 394284 394291
      400294 409294 418288 428279 435272 463236 470229 475219
 0.25 375916 373906 365901 359894 354888 348882 348875 347868
      344864 341861 337852 334850 330849 321849 300853 280858
      262864 255869 248875 243883 242891 244898 247903 249907
      251912 249917 248921 244925 241931 240938 242942 245944
      251944 261942 278937 288935 299934 309935 318937 327941
      334941 342939 350935 359931 366927 372922 375916
 0.50 496876 496865 492857 487853 483846 474835 469829 463826
      460826 458830 458836 459842 462849 459857 454861 452862
      455863 470865 474879 483890 487890 489888 495882 496876
 0.50 480165 481163 480161 478162 477164 478165 479166 480165
 0.50 462223 463218 459216 453214 450215 441217 437217 431217
      428216 426214 420207 412193 404195 394194 388193 383191
      377186 369183 364182 360183 361188 363191 369199 374204
      377209 376211 368214 362210 355206 352206 354210 359218
      362222 366223 373227 377228 382229 393242 399248 404257
      404263 405270 405281 409285 414286 418285 424278 430270
      435266 441258 443253 445247 447243 451240 453237 456229
      462223
 0.50 465881 464874 461871 457871 454873 451877 449880 447884
      446889 447894 450897 453895 456891 459888 461886 464881
      465881
 0.50 450163 451159 451156 448150 444145 441139 438135 434136
      432138 431145 432152 435157 438162 443165 447166 449165
      450163
 0.50 447114 448102 448099 443098 434095 428089 425091 427096
      429099 430103 428105 425107 425110 423114 419116 423121
      426122 430120 436116 440114 443118 447114
 0.50 363923 363917 361914 358912 355908 352901 353897 351892
      347888 341881 339870 334865 330861 323857 313856 304856
      286859 277862 270865 258873 251879 249885 252890 256893
      255898 256903 261904 265904 264909 259915 255921 249927
      247930 247935 249938 253938 261935 271934 279931 286930
      296929 306928 314929 329934 339936 345932 355927 360925
      363923
 1.00 438241 439237 437235 433230 431228 428229 424232 415229
      417218 415215 413214 409213 406206 402201 397198 390196
      384193 373186 367183 364184 364188 371198 386217 392216
      399219 404220 406222 405226 403228 392228 389231 391234
      394238 404245 410249 414255 415262 418267 423263 427258
      430255 433249 438241
 1.00 442154 442152 441151 440151 439151 440152 440153 441154
      442154
 1.00 444111 445108 444106 443103 442103 441102 439102 437102
      436102 435104 435105 436107 435108 434109 435110 437110
      438110 439110 440110 442110 443111 444111
 1.00 432097 431096 430094 429093 429094 429095 430097 431097
      432097
 1.00 374223 373221 373220 373218 372217 370217 369219 370221
      370222 371223 373223 374223
 1.00 364218 363216 363215 362214 360213 359214 360215 360217
      361218 363219 364218
 1.00 347923 346923 344922 343922 341922 339923 337923 337924
      339924 341924 343924 344924 346923 347923
 1.00 333889 330883 329872 318864 312862 302861 293862 284863
      277866 270869 265872 260878 269888 271891 276891 285889
      292888 302888 320887 327889 330890 333889
 1.00 332913 328910 322908 317906 313902 308900 302902 295903
      290906 288910 282914 278916 275921 268923 274925 279923
      286924 293924 301922 312918 317916 323915 332913
 1.50 431246 428236 423235 418233 414231 413226 415221 414217
      412216 409217 408220 408227 405231 401232 397234 398238
      402242 407243 413245 421250 426250 429248 431246
 1.50 407215 406210 404207 398200 388196 381192 373187 370185
      366185 366189 369192 375200 380206 385213 396216 401218
      406217 407215
 1.50 319873 317869 314867 306866 298866 292866 283869 278873
      277877 279879 283884 292883 301882 309881 315877 319873
 1.50 307914 306911 304909 301909 299910 295911 293913 292914
      289916 290920 292921 295920 297920 301918 303917 305916
      307914
 2.00 428242 428240 425237 421236 419235 416234 414234 411233
      407234 409237 412240 413241 417242 420244 423245 426244
      428242
 2.00 413221 413219 412218 411219 411220 412221 413222 413221
 2.00 404214 402207 400204 396201 389198 383194 376190 369187
      368190 370193 375198 380204 384209 388212 393213 399216
      403216 404214
 2.00 309875 308873 306872 305872 303872 301872 299873 298874
      297874 296876 295876 296877 298877 299877 301877 303877
      305876 307877 308876 309875
 3.00 400213 399208 397205 394202 389200 386198 381196 379198
      380200 383204 386207 390209 395212 398213 400213
 4.00 397208 395206 394205 394204 392204 390203 389202 387202
      386200 385200 385202 385203 387204 388205 389206 390207
      392208 393209 395209 397208

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.