Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 251908
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
208 PM EST SAT FEB 25 2017


PRELIM DAY 1 QPF DISCUSSION
VALID FEB 26/0000 UTC THRU FEB 27/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

COASTAL MID ATLANTIC INTO NEW ENGLAND

THE SHARP UPPER TROF INITIALLY EXTENDING FROM THE GREAT LAKES INTO
THE OH VALLEY WILL BECOME INCREASINGLY NEGATIVELY TILTED AS IT
LIFTS NORTHEASTWARD THROUGH THE MID ATLANTIC---NY STATE AND NEW
ENGLAND TONIGHT INTO EARLY SUNDAY.  THIS WILL HELP CONTINUE TO
ACCELERATE THE ASSOCIATED SURFACE FRONTAL BOUNDARY VERY QUICKLY
EASTWARD EARLY DAY 1 THRU THE COASTAL MID ATLANTIC---NORTHWARD
THROUGH NEW ENGLAND.  THE DEVELOPING AREA OF CONVECTION ALONG AND
AHEAD OF THE FRONT THIS AFTERNOON EXPECTED TO REMAIN WELL DEFINED
AT THE BEGINNING OF THE DAY 1 PERIOD IN A REGION OF STRONG
BOUNDARY LAYER CONVERGENCE AND ABOVE AVERAGE PW
VALUES---STRETCHING FROM THE COASTAL MID ATLANTIC--NORTHWARD THRU
EASTERN NY/FAR WESTERN NEW ENGLAND.  THIS CONVECTION WILL CONTINUE
TO PUSH RAPIDLY EASTWARD DURING THE FIRST 6 TO 9 HOURS OF DAY 1
THROUGH NEW ENGLAND--WITH A BRIEF PERIOD OF HEAVY RAIN.  THE
OVERALL FAST MOVEMENT OF THE SYSTEM WILL LIKELY KEEP PRECIP TOTALS
IN THE MODERATE RANGE... .25-.50"+---WITH ISOLATED HEAVY TOTALS
POSSIBLE.  FOR QPF DETAILS--THE DAY 1 WPC QPF LEANED TOWARD THE HI
RES ARW AND NSSL WRF GIVEN HIGHER CONFIDENCE IN THESE MODELS
PRECIPITATION FORECASTS.

NORTHERN PLAINS---UPPER MS VALLEY INTO THE GREAT LAKES

CYCLONIC FLOW IN THE WAKE OF THIS UPPER TROF WILL SUPPORT LAKE
EFFECT SNOW SHOWERS OFF THE UPPER LAKES EARLY IN THE DAY 1 PERIOD
AND OFF THE LOWER LAKES THROUGH SUNDAY MORNING.   WHILE LAKE
EFFECT SNOW SHOWERS WILL BE DIMINISHING EARLY DAY 1 OFF THE UPPER
LAKES---LARGER SCALE ISENTROPIC LIFT AHEAD OF A WEAK SURFACE LOW
MOVING EASTWARD ACROSS THE NORTHERN PLAINS INTO THE UPPER LAKES
WILL SUPPORT ADDITIONAL LIGHT SNOWS SPREADING EASTWARD OUT OF THE
UPPER MS VALLEY AND INTO THE UPPER LAKES TONIGHT INTO SUNDAY.

CENTRAL TO SOUTHERN COASTAL CALIFORNIA

THE SHARP POSITIVELY TILTED TROF OFF THE NORTHERN CALIFORNIA COAST
THIS AFTERNOON WILL BE PUSHING QUICKLY SOUTHEASTWARD ACROSS
CENTRAL TO SOUTHERN CALIFORNIA TONIGHT INTO EARLY SUNDAY.  MODEL
CONSENSUS IS FOR THE BULK OF THE PRECIP TO REMAIN OFF THE CENTRAL
CALIFORNIA COAST--WITH THE EASTERN EDGE BRINGING .10-.25" AMOUNTS
TO COASTAL CENTRAL CALIFORNIA.  FARTHER TO THE SOUTH ACROSS
SOUTHERN CALIFORNIA---THE LOW LEVEL FLOW WILL HAVE A MUCH STRONGER
ONSHORE WESTERLY COMPONENT---SUPPORTING MORE WIDESPREAD MODERATE
RAIN POTENTIAL FROM IN THE VICINITY OF PT CONCEPCION EASTWARD
THROUGH THE TRANSVERSE RANGE AND SOUTHWARD THROUGH THE HIGHER
TERRAIN EAST OF SAN DIEGO.  .25-.50"+ AREAL AVERAGE AMOUNTS
DEPICTED HERE.

PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES

IN THE WAKE OF THE LEAD AREA OF EASTERN PACIFIC HEIGHT FALLS
MOVING INLAND INTO CENTRAL TO SOUTHERN CALIFORNIA---ADDITIONAL
HEIGHT FALLS WILL AMPLIFY ALONG THE PACIFIC NORTHWEST COAST
TONIGHT---MOVING INLAND ON SUNDAY. PW VALUES ARE NOT EXPECTED TO
BE ANOMALOUS WITH THIS NEXT CLOSED LOW---MOSTLY BELOW SEASONAL
NORMS.  HOWEVER---STRONG ONSHORE WESTERLY FLOW WILL SUPPORT .50-1"
AREAL AVERAGE PRECIP TOTALS THROUGH THE WASHINGTON/OREGON
CASCADES---WESTWARD TO THE WASHINGTON/OREGON COAST RANGE AND SOUTH
INTO FAR NORTHWEST CALIFORNIA.  LIGHTER TOTALS OF .10-.25"
EXPECTED INLAND FROM NORTHEAST OREGON---NORTHEAST WASHINGTON STATE
INTO CENTRAL TO NORTHERN ID AND NORTHWEST MT.

ORAVEC

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

24HR QP VT 27/00Z
 0.01 494611 498617 502626 508639 511647 515657 518666 521676
      525698 524709 525725 524736 522742 517746 509748 496746
      485743 470743 461744 455748 446759 441764 440767 439772
      443781 447785 450786 460797 461788 465782 470776 471768
      472764 472761 473758 473754 472748 474745 477747 482752
      483756 487759 490766 496780 497786 498790 498796 497803
      496812 494822 492832 490840 490848 490859 489871 489882
      489895 489910 488914 489921 492928 492932 491937 491942
      487944 486942 482942 481948 481954 481977 484984 486992
      487000 487010 486022 485025 484032 482040 476047 471051
      466045 463038 464030 463024 464012 466009 467003 467999
      465996 462994 461991 459982 458972 458962 457951 458946
      457940 456930 456917 457905 454896 454890 456886 457874
      457867 452861 445860 431862 428862 424860 420860 420856
      422851 425850 427852 432852 435854 440850 451837 453835
      455830 451823 449819 445817 441818 438815 434809 432804
      432798 429796 427799 422804 417809 413810 412808 411799
      410794 407792 404794 399795 397798 393799 387805 384807
      379807 376806 377804 381797 385792 389790 394788 397786
      402785 408780 411776 414769 415763 414758 412753 410751
      407750 403751 397751 391748 385746 377749 370755 359764
      356767 351768 348766 348762 353757 358750 368741 374737
      380732 389724 400713 410702 414696 419690 423686 427684
      425681 411676 406670 405665 406660 407655 410650 413644
      417638
 0.01 356282 358272 362268 368268 375269 385264 390260 395254
      398248 404250 412253 422255 435258 440257 448259 460259
      466261 470264 482273 493284 497287 503289 508287 512281
      516273 519264 522255 524243 522236 522230 524227 530216
      537203 540195 543185 546174 547166 547158 547154 547147
      546141 544134 540129 533119 522112 518109 514110 512116
      514126 518142 519146 517150 513147 508142 502138 490129
      480119 478111 477102 476095 474091 469093 465100 460103
      454098 452094 448094 442096 431094 427089 426091 430097
      431101 428103 425103 423105 426108 430112 431114 435115
      441119 446123 449124 451122 454125 456129 457132 456134
      453136 450142 446146 444148 442147 437140 434140 433145
      433150 434153 435160 441173 438177 434180 432186 436193
      438195 439199 442201 445204 448204 450201 454196 460191
      467193 470195 472198 473201 471205 466207 461204 459205
      457210 452213 443213 429207 424202 423200 419201 419206
      420209 421215 419217 415215 412214 409215 406217 408224
      406227 402228 398226 391225 386228 381231 376231 375220
      371213 365208 362207 360203 357198 354190 348185 347179
      346171 344166 336163 322159 319159 317161 314165 316177
      312193 312199 316203 320201 324201 324206 317223 316232
      315238 316241 319255
 0.01 449080 449078 448075 447072 446072 445070 443069 441069
      441072 443074 444075 446077 448078 449080 449080
 0.01 451049 452034 451029 451024 449021 449017 451012 450008
      450000 446993 441993 441997 441004 439009 438024 438038
      443045 446048 449049 451049
 0.01 401209 399206 396202 393199 390196 386193 381192 380190
      377194 379197 382200 385203 390206 393209 397210 400209
      401209
 0.01 416066 411059 403055 399056 395059 391060 386060 384058
      382062 384067 384069 381068 368054 367052 362051 357052
      352053 350055 350062 348065 345065 343061 339056 336056
      330055 327056 332061 335069 338077 338082 334079 330077
      327080 325084 326087 329090 330094 332099 332104 343120
      348125 359127 362125 365121 363118 360116 356113 355109
      354105 354102 355095 355091 357087 358073 360069 365068
      369078 371083 373084 378084 382086 387091 388084 392082
      400082 408077 410076 413072 416066
 0.01 411108 409100 408098 406102 405105 404108 402108 394110
      389112 386114 384117 375127 381130 380142 382158 385161
      387160 392161 394163 398164 400162 401150 402142 398134
      395126 396120 398117 401117 402120 406121 407117 411108
 0.01 382920 382916 380915 377916 375918 373923 370929 369936
      368938 368943 369945 370949 373952 375947 377945 377940
      379938 379934 381927 381922 382920
 0.01 345956 343952 337949 330951 323951 308951 304951 301949
      296949 282953 270949 263949 257950 254957 253960 250960
      245958 238957 236958 234961 235968 238973 242978 251984
      256988 258990 258995 258999 260001 266003 281003 288002
      292000 296996 299989 304985 308983 328969 333967 338964
      340961 343960 345956
 0.01 268794 267789 263789 256791 250796 246801 243807 239813
      240818 243821 246823 252818 255812 260806 265800 268794
      268794
 0.25 470620 471625 473625 476622 481621 487623 495629 502639
      505643 507648 513665 515672 516680 515693 513701 509703
      503707 499707 498706 495698 493693 489688 485687 482688
      478691 474695 471701 467706 466712 470714 482714 491716
      496718 501721 500726 499728 494732 482732 460731 449734
      438736 428736 415734 413732 412729 415724 418719 422718
      433718 438716 439712 439709 437707 431706 430705 431702
      435697 443689 447685 452681 454667 455661 459655 463652
      468649 478642 475637 472632 470629 465630 458630 455631
      452634 449636 447635 446629
 0.25 503273 504267 504262 503253 500245 498244 496248 492242
      492238 495238 497235 499232 498221 499213 496204 494202
      490200 484202 474208 468212 462213 457215 450217 443216
      436217 424219 422224 424227 425231 422234 416232 409235
      407238 406241 411245 425248 440249 453250 467249 482253
      485253 486256 490263 496270 500274 503273
 0.25 495658 495655 493655 493656 495658 495658
 0.25 501173 500169 498166 490163 485158 481156 477156 471152
      464154 465158 467162 472166 479170 485175 493176 498175
      501173
 0.25 482232 483229 482229 480228 480229 481231 481232 482232
 0.25 485138 484136 484135 482134 481133 479133 477133 476132
      474133 473136 474138 475139 477139 479140 480140 482140
      484141 485138
 0.25 481847 480844 478842 477840 475837 473835 472833 469831
      468831 468836 469838 471842 472845 474848 477849 478851
      480849 481847
 0.25 459180 457179 456179 455179 455180 456182 457182 459180
      459180
 0.25 377242 367236 362232 363227 364223 364220 363216 358213
      354209 350205 347200 344186 343173 343169 341168 334166
      328165 330170 331177 331182 333184 337180 340185 341199
      336213 334220 335226 341235 340242 339250 339263 340266
      343267 347264 355257 364250 371246 376244 377242
 0.50 506664 506659 504659 502660 499664 498665 495667 493669
      492672 492677 493682 495682 498681 501679 503678 505675
      505672 506667 506664
 0.50 489216 489213 487210 484209 483209 479210 477210 474212
      473214 473218 476219 480219 483219 485219 487218 489216
 0.50 481244 480238 476232 470232 466230 463231 461233 458232
      452234 446234 441237 437237 433235 430237 426237 420236
      416235 414237 416242 424244 430245 436243 442242 448244
      462245 468243 474244 479245 481244
 0.50 477671 476666 475664 473662 470661 468661 465661 462663
      462666 462671 463674 465675 468675 472674 475673 477671
 0.50 482726 482723 481723 480722 478722 476721 474721 473723
      472726 473727 474728 475728 477729 479729 480728 482726
      482726
 0.50 466690 465685 462684 455687 443693 438698 437700 440701
      445703 452706 452711 449713 443718 438721 432725 428729
      434730 449727 455723 457720 457717 454711 454708 457705
      461700 464694 466690
 0.50 450225 450219 447219 442219 438221 434222 429220 425221
      426225 430228 433230 438231 442230 445228 448226 450225

$$




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