Quantitative Precipitation Forecast
Issued by NWS

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011
FXUS04 KWBC 090828
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
326 AM EST TUE FEB 09 2016


PRELIM DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 09/1200 UTC THRU FEB 12/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR

DAY 1

...COASTAL LOW DEPARTING NEW ENGLAND EARLY TODAY...

WATER VAPOR SATELLITE IMAGERY CONTINUES TO SHOW AN IMPRESSIVE
CYCLONE HEADING NORTHEAST INTO THE WRN ATLANTIC.  COMPOSITE RADAR
SATELLITE IMAGERY STILL SHOWED SOME PRECIPITATION WAS LINGERING
OVER PARTS OF NEW ENGLAND...ALTHOUGH PCPN WAS GRADUALLY COMING TO
AN END FROM SOUTHWEST TO NORTHEAST. BY LATER TODAY...ONLY SOME
LIGT PCPN IS EXPECTED IN THE WEST FACING AND NORTH FACING
MOUNTAINS IN NORTHERN NEW ENGLAND AND ALONG THE IMMEDIATE COAST OF
ME.

...COLD TROUGH DIGGING TOWARD THE OHIO VALLEY AND MID ATLANTIC...

A LONGWAVE TROUGH OVER THE EASTERN HALF OF THE NATION WILL BECOME
BETTER DEVELOPED THROUGHOUT THE DAY...WITH A BROAD AREA OF HI RH
WITHIN THE BROAD CYCLONIC CIRCULATION.  A MID AND UPPER LEVEL JET
STREAK EMBEDDED WITHIN THE FAST FLOW HAS BEEN MAKING ITS WAY
TOWARDS THE MID ATLANTIC EARLY THIS MORNING...WITH WHAT IS STILL A
DISORGANIZED AND COMPLEX AREA OF LOW PRESSURE NEAR THE VA/NC
BORDER COAST.  AS THIS LOW BECOMES BETTER ORGANIZED LATER
TODAY...AN INVERTED TROUGH AXIS SHOULD FORM AND EXTEND WEST OF THE
LOW.  THE CONVERGENCE ALONG THE TROUGH AXIS...STEEPENING LOW LEVEL
LAPSE RATES AND FAVORABLE UPPER LEVEL SUPPORT SHOULD HELP THE
PRECIPITATION PROCESSES.  THE 09/00Z GFS...NAM AND UKMET WERE MOST
HEAVILY USED WHILE PREPARING THE MANUAL WPC QPF...ALTHOUGH WE WERE
ABLE TO INCORPORATE SOME OF THE 00Z ARW/NMMB TO FOCUS SOME OF THE
HEAVIER QPF.

ACROSS THE GREAT LAKES...850 MB TEMPS WILL BE PLENTY SUFFICIENT
FOR LAKE EFFECT SNOW SHOWERS WITH THE COLDEST TEMPS LIKELY OVER
WRN LAKE SUPERIOR WITH 850 MB TEMPS LOWERING FROM -12C TO -21C.
NORTHWEST FLOW FAVORS HEAVIEST AMOUNTS OVER PARTS OF THE U.P. OF
MICHIGAN AND OVER WESTERN/NORTHWESTERN LOWER MI TO THE LEE OF LAKE
MICHIGAN.  THE PREVIOUS SHIFT KEYED IN ON THE COLDEST H85 TEMPS
BEING OVER WESTERN LAKE SUPERIOR AND WE SAW LITTLE REASON TO MAKE
CHANGES THERE.

...COLD FRONT PUSHING INTO THE SOUTHEAST U.S. AND FLORIDA...

INSTABILITY SHOULD REMAIN FAIRLY LIMITED ACROSS THE SOUTHEAST AND
FL TODAY AND TONIGHT WHICH LEADS TO SCATTERED NATURE OF ANY
SHOWERS WHICH FORM AND FAIRLY MODEST RAFL RATES/AMOUNTS.  WPC QPF
RELIED ON A BLEND OF THE LATEST HI-RES MODELS FOR THIS REGION OF
THE COUNTRY.

DAYS 2/3...

...GREAT LAKES/APPALACHIANS/NORTHEAST...

DEEP UPPER-LEVEL TROUGH WILL BE IN PLACE ACROSS THE EASTERN U.S.
AT THE START OF DAY 2 /18Z WED...WITH A SURFACE LOW CENTERED OFF
THE COAST OF SOUTHERN NEW ENGLAND. AN INVERTED TROUGH EXTENDING
WESTWARD INTO THE NORTHEASTERN U.S. ALONG WITH A SHORTWAVE
CROSSING THE NORTHERN MID-ATLANTIC REGION WED MORNING WILL RESULT
IN THE POTENTIAL FOR A FOCUSED BAND OF PRECIPITATION WHICH WILL BE
ONGOING AT 12Z WED ACROSS LONG ISLAND AND THE SOUTHERN NEW ENGLAND
COASTLINE. WPC QPF ACROSS THIS AREA REPRESENTS A NORTHWARD SHIFT
AMONG THE GFS/UKMET/ECMWF WITH THEIR 00Z RUNS...BRINGING SOMEWHAT
HEAVIER QPF AMOUNTS INTO THIS AREA.

ELSEWHERE BENEATH THE LONG WAVE UPPER TROUGH...LAKE EFFECT SNOWS
WILL OCCUR ON WED AND THURS. COVERAGE OF LAKE EFFECT SNOWS WILL
BEGIN TO DIMINISH IN COVERAGE AND INTENSITY BY THURS. UPSLOPE
SNOWS WILL ALSO OCCUR ALONG THE SPINE OF THE APPALACHIANS...WITH
COVERAGE AND INTENSITY AGAIN DECREASING BY THURSDAY AS COMPARED TO
WEDNESDAY.

WPC QPF GENERALLY FOLLOWED A BLEND OF THE GFS/ECMWF AND IN-HOUSE
PSEUDO BIAS-CORRECTED ENSEMBLE GUIDANCE...WITH SOME MANUAL
ADJUSTMENTS IN LAKE EFFECT BANDS AS WELL AS UPSLOPE AREAS.


...NORTHERN PLAINS TO MID-MISSISSIPPI VALLEY...

AN ARCTIC SURFACE FRONTAL BOUNDARY WILL PERSIST ACROSS THE PLAINS
THROUGH DAYS 2 AND 3...WITH RELATIVELY WEAK AND FAST-MOVING
MID/UPPER-LEVEL SHORTWAVES TRAVERSING THE REGION. THE FIRST
SHORTWAVE WILL MOVE FROM THE NORTHERN PLAINS INTO THE MID/UPPER
MISSISSIPPI VALLEY ON WEDNESDAY. THE SECOND
SHORTWAVE...ACCOMPANIED BY A MORE ROBUST WAVE ALONG THE ARCTIC
SURFACE FRONT...WILL MORE ACROSS THE NORTHERN PLAINS INTO THE
UPPER MIDWEST THURSDAY/THURSDAY NIGHT. BOTH SYSTEM WILL BE
RELATIVELY STARVED FOR MOISTURE...AND WILL RELY LARGELY ON THE
UPPER-LEVEL FORCING TO GENERATE PRECIPITATION. THE SECOND WAVE
WILL HAVE A LITTLE MORE LOW/MID-LEVEL SUPPORT TO TO STRONGER
THERMAL ADVECTION AHEAD OF THE WAVE. NONETHELESS...DUE TO THE
FAST-MOVING NATURE OF THESE SYSTEMS...QPF AMOUNTS ARE LIGHT WITH
MOST AREAS RECEIVING LESS THAN TENTH OF AN INCH LIQUID FROM EACH
SYSTEM. WPC QPF WAS COMPRISED OF A BLEND OF THE GFS/ECMWF ALONG
WITH IN-HOUSE PSEUDO BIAS CORRECTED ENSEMBLE GUIDANCE.


...NORTHWEST...

THE UPPER-LEVEL RIDGE ACROSS THE WESTERN U.S. WILL BE RATHER SLOW
TO BREAK DOWN -- BUT A MID/UPPER-LEVEL SHORTWAVE AND A COLD FRONT
WILL APPROACH THE NORTHWEST ON THURSDAY. MODELS SHOW SOME TIMING
DIFFERENCES...BUT GENERALLY EXPECT PRECIPITATION TO INCREASE IN
COVERAGE AND INTENSITY ACROSS WESTERN WASHINGTON AND OREGON LATE
THURSDAY INTO THURSDAY NIGHT. WPC QPF REPRESENTS A COMPROMISE IN
TERMS OF TIMING...TAKING A BLEND OF THE GFS/ECMWF AND IN-HOUSE
PSEUDO BIAS CORRECTED ENSEMBLE GUIDANCE.


GRAPHICS AVAILABLE ON THE WEB AT WWW.WPC.NCEP.NOAA.GOV

BANN/RYAN


24HR QP VT 10/12Z
 0.01 563046 560043 557036 555023 554018 551014 547011 542010
      524003 508993 498989 491984 487982 482981 474976 465971
      456969 445968 436973 435978 434985 436990 438994 437996
      434996 432999 431003 429004 426008 429021 432023 435022
      434017 436014 439014 447022 456025 462033 467041 470046
      475049 482056 490059 497064 505070 508071 510074 515074
      522072 528079 535088 541095 545098 549099 551095 554089
      555082 555077 556073 558055 563046
 0.01 509288 509281 507276 505272 504265 504258 502254 495246
      478244 472243 468244 465245 459244 442249 438248 434250
      430251 426254 427257 429258 433258 443258 452258 462258
      466258 471259 480265 485268 488271 495279 502286 506289
      509288
 0.01 335683 336688 333695 325704 320713 316724 306746 313775
      315792 317798 319796 324795 326795 328792 331787 336778
      342768 345763 350758 356750 360748 362749 367753 371756
      372759 372763 372771 373776 375779 383786 385789 384792
      382796 372804 370809 366813 361817 357821 350831 347836
      342839 338834 333837 332843 333849 329858 337867 340868
      341871 345876 351884 355888 358888 361890 366892 369887
      368878 374874 391864 391867 393870 393878 397894 400898
      404901 409899 417898 420898 422896 430895 435892 442895
      448894 451897 453901 455904 459907 463912 465913 468913
      472910 474904 477899 481891 483885 486879 488873 492868
      496863 499855 505844 507839 509833 513817 515802 516786
      517769 515747 514737 512724 510719 509710 506703 505695
      493665 490659 486654 480645 472636 469631 467629 465632
      456653 451654 448657 439668 432678 428683 425688 424694
      423698 421700 420693 422684 423678 423672 420666 418664
      415665 408667 404668 401667 392664 380661 379659 377660
      372663 366668 361671 345676
 0.01 447717 446705 445693 443689 439687 433693 430699 426708
      419709 416713 416717 419725 426726 435725 444722 447717
 0.25 552061 552060 551058 551057 550058 551060 552061 552061
 0.25 550050 550047 547045 544044 542043 539043 536043 534045
      536048 538051 540054 541056 543057 545057 548055 549052
      550050
 0.25 518028 517024 516022 513020 509020 506021 504022 503026
      505029 506032 509034 512034 514033 517030 518028
 0.25 475882 475877 474875 471868 469861 468858 465858 463864
      463868 463873 466881 467888 465895 465903 468900 471895
      473888 475882
 0.25 456842 456835 454830 451828 450823 447819 444817 435814
      432813 426814 424817 425824 429832 431837 434837 438835
      443834 448836 450840 452845 454845 456842
 0.25 451857 450856 448857 447858 446858 445860 443861 445861
      446861 448861 450860 451857
 0.25 426864 426862 424860 422859 420859 419859 417860 417861
      416863 416865 416868 417868 419869 421868 423867 424866
      426865 426864
 0.25 418811 418809 417808 417809 417811 418813 418811
 0.25 408759 407749 405743 403725 401715 398710 395705 391699
      387695 386691 387687 385683 384681 381680 375680 368681
      362683 356687 353691 350696 347700 346708 347717 350722
      356722 360718 367709 371713 373720 373729 376737 381748
      384757 385763 385767 390771 399778 405777 408775 407771
      408759
 0.25 403795 401790 397791 394794 390796 386799 384802 382807
      385809 387808 393810 396807 399803 401800 403795
 0.50 398728 398724 394721 388714 384713 381716 378725 378732
      380738 383741 385745 387750 389753 392754 393752 393745
      389735 390732 392738 396740 398735 398728
 0.50 399765 399763 399762 398763 398765 399766 399765

24HR QP VT 11/12Z
 0.01 536210 537202 535197 530190 526182 520173 517171 514172
      510174 510178 516185 519194 522205 524210 527214 532214
      534212 536210
 0.01 520271 522258 522253 521247 515231 510224 505218 500212
      494210 491209 489210 486213 485217 487226 485231 481231
      477229 473229 467233 463238 457243 444249 439254 434256
      426258 421263 415266 410270 405277 402289 403293 405296
      407299 412301 420303 426306 435309 441307 447305 454301
      459296 464292 467289 471290 476291 479290 493290 497290
      504293 508293 513291
 0.01 534021 534016 532013 529010 518004 510996 500990 492985
      487982 482977 464964 444953 426940 409926 405922 401916
      396908 390897 387890 383886 380880 377877 372873 368871
      363874 361879 363885 366890 375914 389935 391940 395945
      402952 418970 428978 435983 438983 440986 445990 454996
      464002 468006 473009 482014 492021 516022 527026 530027
      532025 534021
 0.01 508794 506772 504765 503755 503749 501747 496745 492744
      487747 486750 483751 481753 479749 477744 475736 474726
      473721 471719 468714 468710 469707 473702 476695 476689
      473685 470683 467684 460686 455690 451694 444703 443704
      440704 436700 444688 452679 457666 459654 456651 453651
      447653 442656 435659 431662 427662 426659 421653 419652
      416652 406658 398665 389674 377674 371677 365681 357689
      349699 347704 345710 341721 339726 335730 322750 315759
      314762 313767 312774 311777 312781 313788 320788 325786
      342770 348760 352756 357753 364754 370756 381752 385749
      390744 394740 397738 401738 409742 413745 415750 416758
      416764 418766 419771 415776 411777 409779 404781 399785
      393789 388791 384795 380800 376803 373809 369812 364814
      359819 357824 357829 356832 354838 353840 356840 359834
      362832 366834 368838 376838 381848 383850 386850 391847
      396844 401846 410854 412856 412861 415870 419874 424876
      437876 450874 455874 458875 460878 460897 461903 464907
      470907 472905 480892 482888 484881 485877 484871 483863
      479848 477846 479842 484839 492830 499822 503811 506801
      508794
 0.25 516272 518267 518261 516254 513247 510241 502228 498223
      495220 493223 492227 494235 494239 493243 488241 484244
      479249 478255 481262 485268 490273 499282 505284 510281
      516272
 0.25 448276 449274 447271 446272 445272 444273 443274 441275
      441276 440278 440280 438282 438283 439285 439286 440286
      441285 443284 443283 445282 446281 446280 447278 448276
      448276
 0.25 440762 440760 440757 439755 438754 437754 435755 435756
      433757 432759 431761 431764 432766 433768 433769 434770
      435771 436770 437770 438767 439765 439763 440762
 0.25 434780 434778 432777 431778 430779 430781 429783 429786
      431787 433786 433785 434783 434781 434780
 0.25 429788 429784 427783 425782 424787 422792 420795 416799
      416804 419807 421804 423799 425794 427791 429788
 0.25 391711 390704 386700 383699 382694 381686 378685 375687
      372692 366701 359711 353722 351727 350731 356733 363733
      369733 375731 383722 391713 391711
 0.50 515267 515264 515261 515259 515257 514256 514253 513253
      512251 511249 509248 508248 507250 507252 507253 508256
      508257 508259 509261 510262 510264 511265 512266 513268
      515267
 0.50 506276 504271 502267 499263 497260 495256 492253 488254
      489260 492265 494269 496273 498276 503279 506276
 0.50 378705 377700 375700 372702 370704 368706 367708 365711
      365715 366717 370718 373715 375713 376710 377707 378705

24HR QP VT 12/12Z
 0.01 537207 537201 535198 534193 532189 525174 524171 520169
      514166 511164 508161 503155 497150 496148 491147 486151
      484153 483158 482171 485179 491182 497187 507198 512205
      516209 520210 523209 528206 534207 537207
 0.01 546095 544079 540071 536067 532061 529055 524052 521046
      517043 513036 509029 506021 503016 498011 495008 489005
      485000 483994 474982 467971 464966 460959 454949 447935
      443923 438909 432896 427890 422886 416884 410884 404887
      402892 399898 399907 401916 403922 410935 417945 424954
      430959 435961 443971 447977 450983 455996 458003 461008
      469020 473024 476024 478027 482030 486036 490043 493051
      505073 509078 513084 517090 522094 526100 531103 532106
      535107 539108 540105 542105 544100 546095
 0.01 518268 520262 521253 521246 520240 519235 517230 513222
      503206 500203 496202 491200 486200 479201 472207 467212
      463215 459217 452220 448222 446226 444229 440231 432234
      426239 418241 411242 404245 400246 397250 394255 391258
      391261 396262 403260 410258 419262 424268 426271 425275
      424282 426292 427296 430300 433303 438305 448309 457313
      466315 483315 490313 497308 502302 507293 514280 518268
 0.01 474634 474626 471622 460626 453633 448638 444642 436649
      430651 427653 422656 417660 413661 408660 400657 389660
      382662 377665 369672 361679 356687 354692 353696 352709
      353716 354720 357725 359730 359737 362742 371746 380748
      383750 389749 397742 402740 406736 411730 418720 423708
      425706 427705 429707 432706 447695 452698 454701 451703
      444710 439712 435714 430716 427720 425727 423729 423732
      428736 431734 434734 436736 436740 433742 421744 418747
      417753 420761 421768 419773 410779 402785 391791 384797
      381802 379806 380810 382810 385809 387807 394802 399800
      402799 404801 408805 409811 412815 419814 425816 428820
      438824 446829 453833 455835 457830 455825 455818 456811
      457804 458797 457788 457783 455783 450782 447785 445793
      442796 441801 439806 436808 433807 427800 429795 432792
      435790 435787 437781 439775 440767 446759 451748 457738
      459734 460729 459714 460708 464706 469708 472706 474701
      473694 471691 468690 464688 460684 458675 462665 461657
      462654 464653 469646 474634
 0.01 483867 481856 480852 478849 474842 473837 473830 472824
      470823 468824 465829 464839 463842 459844 452843 447846
      445849 442851 438858 438862 440864 447866 455865 459864
      462866 463872 464879 463884 464890 465894 468896 472895
      474892 478885 480877 483867
 0.01 428862 428860 427859 426857 424857 422855 420855 418855
      417855 415856 415858 415861 415863 417865 419865 421865
      422865 424865 426863 428862 428862
 0.25 517265 518258 517249 512238 507227 502217 498212 493209
      488208 483208 479212 480217 481220 482222 481226 475226
      471227 466231 458237 455240 454245 454249 456250 456259
      449270 447276 447280 448283 450286 453287 460288 469288
      474286 479285 490288 495288 500287 504285 508281 517265
 0.25 469856 468853 467853 466853 466856 467858 469858 469856
 0.25 433766 433764 432763 432761 430760 429761 429762 428764
      429767 431768 433766 433766
 0.25 393711 391707 388703 385701 380701 376703 374706 371711
      369714 369721 373723 378722 383721 387719 391716 393713
      393711
 0.50 514266 515259 515253 514248 512242 504225 499216 496214
      491212 486211 483215 483219 486224 488228 488233 486235
      482236 479233 475230 471233 469236 468240 470251 466259
      461268 463272 468274 484273 488275 491278 498281 503281
      506279 510269 514266
 1.00 502272 501261 497250 497244 500245 504247 504244 501235
      500229 497226 495228 495233 494239 490241 487241 484245
      483253 483258 488265 496272 502272
 1.00 477240 478238 478235 477235 476234 475234 474237 475239
      476240 477241 477240
 1.50 493259 493256 493255 493253 492251 492250 491248 491247
      490245 488247 488249 489251 489252 490255 491257 492258
      493259 493259

$$





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