Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 190731
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 AM EST MON FEB 19 2018


PRELIM DAY 1 QPF DISCUSSION
VALID FEB 19/1200 UTC THRU FEB 20/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...EASTERN PLAINS / MID-UPPER MS VALLEY / GREAT LAKES / UPPER OHIO
VALLEY...

CONTINUED AMPLIFICATION OF THE LONGWAVE TROUGH WEST OF THE DIVIDE
AND RESULTANT DOWNSTREAM RIDGING ACROSS THE EASTERN CONUS WILL
LEAD TO A HIGHLY -PNA TOWARD THE END OF DAY 1 (12Z TUE), WITH 500
MB HEIGHT ANOMALIES AROUND 2.5 STANDARD DEVIATIONS BELOW/ABOVE
NORMAL OVER THE WEST/EAST RESPECTIVELY. AS THE PATTERN ALOFT
BECOMES HIGHLY MERIDIONAL, THE SURFACE FRONTAL ZONE DRAPED SW-NE
FROM THE SOUTHERN-CENTRAL PLAINS NORTHEAST INTO THE UPPER
MIDWEST-UPPER GREAT LAKES WILL EXHIBIT LITTLE EASTWARD
PROGRESSION, WITH THE NORTHERN EXTENSION OF THIS FRONT (ESPECIALLY
AFFECTING THE UPPER MIDWEST-UPPER GREAT LAKES) BECOMING BOLSTERED
BY THE STRENGTHENING UPPER JET TO THE NORTH AND THUS INCREASING
RIGHT ENTRANCE REGION DYNAMICAL FORCING. MEANWHILE, MOISTURE
PARAMETERS WILL TOO BECOME HIGHLY ANOMALIES DURING THE DAY 1
PERIOD, WITH PW VALUES RISING ABOVE 4 STANDARD DEVIATIONS ABOVE
NORMAL PER THE SREF AND GEFS AND 850 MB MOISTURE FLUX ANOMALIES
PEAKING OVER +5 STANDARD DEVIATIONS IN LIGHT OF THE 50-60 KT MOIST
SOUTHWESTERLY INFLOW INTO THE FRONTAL ZONE. ACCORDING TO THE
ATMOSPHERIC RIVER DETECTION FROM THE ESRL SITE, A CLEARLY DEFINED
ATMOSPHERIC RIVER IS NOTED FROM THE CARIBBEAN AND WESTERN GULF,
WITH INTEGRATED WATER VAPOR TRANSPORT VALUES EXCEEDING 750 KG/M/S.

FROM A DYNAMICAL AND THERMODYNAMICAL STANDPOINT, PRECIPITATION
EFFICIENCY IS ABOUT AS HIGH AS IT GETS FOR MID FEBRUARY,
ESPECIALLY ALONG/NORTH OF 40N, IN THE ABSENCE OF ROBUST DEEP LAYER
INSTABILITY. WHILE THE LATTER WILL BE A LIMITATION TO SHORT TERM
RAINFALL RATES, THE ROBUST DEGREE OF FORCING AND MOISTURE
TRANSPORT INTO THE QUASI-STATIONARY FRONT WILL SUPPORT THE
CONTINUATION OF A RATHER BROAD MARGINAL RISK FOR EXCESSIVE
RAINFALL DURING DAY 1 ACROSS MUCH OF THE MIDWEST INTO THE GREAT
LAKES AND UPPER OH VALLEY REGION, WITH 2 FOCUSED AREAS OF A MORE
ENHANCED ("SLIGHT") THREAT. WPC DID MAINTAIN THE SLIGHT RISK
STRADDLING THE WI/IL BORDER FROM YESTERDAY`S DAY 2 ERO, IN LIGHT
OF THE ANTECEDENT CONDITIONS/LOWER FFGs, WHILE INTRODUCING ANOTHER
SLIGHT RISK AXIS FROM CENTRAL IL NORTHEAST THROUGH
CENTRAL-NORTHERN IN AND FAR NORTHWEST OH GIVEN THE GROWING
HIGH-RES CONSENSUS OF SPOTTY 24 HOUR TOTALS AOA 3 INCHES. OVER
THIS REGION, THERE REMAINS A MULTI-MODEL SIGNAL FOR HEAVY RAINFALL
ALONG THE AXIS OF MAXIMUM PW VALUES AND 850-700 MB MOISTURE
TRANSPORT INTO THE FRONTAL ZONE, SO DESPITE THE INITIALLY HIGH FFG
VALUES, BELIEVE BY MONDAY NIGHT MORE AREAS WILL BECOME SUSCEPTIBLE
TO FLASH FLOODING WITH ADDITIONAL ROUNDS OF HEAVY RAIN.


...WEST...

THE RATHER DRAMATIC PATTERN CHANGE ACROSS THE WEST IS BEGINNING TO
TAKE SHAPE, AS A VERY COLD FULL-LATITUDE UPPER TROUGH ESTABLISHES
ITSELF OVER THE REGION. IN FACT, 12Z GFS STANDARDIZED ANOMALIES
INDICATE THIS 500MB FEATURE BEING 2.5 TIMES BELOW AVG WITH
HEIGHTS. SIGNIFICANT HEIGHT FALLS WILL DIG FROM THE PAC NW TO
SOUTHERN CA/DESERT SW WITH HELP FROM A VERY DYNAMIC UPPER-LEVEL
JET, WHILE WIDESPREAD SWRLY UPPER DI-FLUENT FLOW ENCOMPASSES THE
GREAT BASIN AND INTER-MOUNTAIN WEST. EXPECT CONCENTRATED QPF ALONG
COASTAL SECTIONS OF OR INTO CA WITH THE ADVANCEMENT OF THE 500MB
MID TO UPPER LOW CENTER AND IN THE WAKE OF UPPER JET, WHERE VERY
COLD 500MB TEMPS SURGE INLAND. MEANWHILE INLAND, THE
AFOREMENTIONED SWRLY UPPER DI-FLUENT FLOW WILL ENCOMPASS THE
REGION AND COUNTERACT THE MARGINAL PAC MOISTURE TRANSPORT FOR
HEAVY OROGRAPHIC QPF FROM MOGOLLON RIM TO THE SAN JUANS/CO ROCKIES
AND WASATCH. ALSO, THE PRESENCE OF SURFACE LOW PRESSURE OVER THE
GREAT BASIN AND STRONG HIGH PRESSURE TO THE NORTH OVER THE
NORTHERN PLAINS WILL YIELD VERY FAVORABLE UPSLOPE FLOW, WHICH
SHOULD ALLOW ORGANIZED HEAVY SNOWFALL TO CONSUME MUCH OF SOUTHERN
AND EASTERN WY TOWARD WESTERN SD. OVERALL THE GUIDANCE IS IN GREAT
SHAPE CONCERNING THE ESTABLISHMENT OF THIS LONG WAVE TROUGH, ALONG
THE DETAILS ON QPF, AND WPC GENERALLY FOLLOWED A MODEL BLEND OF
GLOBAL MODELS AND HI-RES GUIDANCE.

HURLEY/MUSHER


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



THIS DISCUSSION WILL TRANSITION TO MIXED-CASE FEB 26, 2018.  THE
LISTING OF ISOHYET POINTS CONTAINED BELOW WILL ALSO BE ELIMINATED
FROM THE PRODUCT FEB 26, 2018.  ISOHYET GRID INFORMATION WILL
CONTINUE TO BE GENERATED IN A VARIETY OF BINARY FORMATS AND MADE
AVAILABLE THROUGH THE WPC GIS PAGE.

24HR QP VT 20/12Z
 0.01 498321 499313 499308 496299 495293 493287 489280 484273
      474269 464266 459265 455265 450264 447265 439266 435267
      432270 429272 430277 434280 439281 449284 459288 461292
      459300 459306 460311 463315 467318 475322 485326 492326
      495325 498321
 0.01 495722 493707 491705 487707 487712 484715 483711 483703
      483696 474680 471675 471668 472659 473646 474639 471639
      464634 461633 458634 454637 449639 438642 427645 421648
      417651 411658 407665 403677 401689 398696 395704 393710
      392715 391721 389725 380743 379748 376753 367754 361755
      358754 349756 347759 341761 333758 329757 326760 325764
      322767 322771 325774 338774 342775 348775 348778 345781
      343783 342781 338780 335781 332785 327787 325791 324796
      325799 327800 331801 336800 346796 348796 350799 349804
      348809 348816 345826 340834 329842 336841 339843 338845
      330851 329855 329859 330863 333864 333867 337867 340868
      341871 333876 355867 352863 354857 360850 363847 363842
      359843 356847 352850 349849 351847 352842 356840 358836
      358832 356827 360823 368818 369812 372813 377822 377827
      379831 381833 381837 380843 377854 380870 377879 372886
      367895 362902 356908 355903 353900 351899 349901 349905
      351912 350915 348916 342924 337932 328945 323954 317960
      316965 311966 307968 303968 286974 289989 282995 280003
      278005 279007 281012 285014 288016 288019 290023 295023
      304022 307020 312020 316010 321003 329998 336995 343996
      354996 356991 359988 368983 372982 377984 386983 387986
      389983 393979 396977 406971 411972 412978 414978 415981
      413986 403001 398010 393016 389026 389033 387038 386043
      385046 383047 374044 368039 365041 363047 360049 358046
      357042 355040 352043 351045 353053 351054 348054 341053
      335053 330051 326049 323047 319048 322056 323061 320065
      316074 314078 317081 318084 313085 308086 305083 298077
      284069 266062 256058 249057 246060 246067 249075 254083
      261089 265093 268096 276101 283106 288114 291117 297119
      304117 314119 321121 324124 326122 329120 331122 331125
 0.01 331125 329128 329131 332127 335127 338129 343129 346133
      350139 355140 362138 366142 371145 372147 372150 368151
      362154 362157 364159 366157 371152 376150 382147 385148
      385151 381156 382158 384156 387154 389155 389159 387164
      385167 380163 375161 377164 382170 384172 383176 382182
      377181 374183 370183 363181 357181 351182 346187 346192
      347195 353200 354198 352195 352190 355188 358190 364192
      370196 375200 379204 385207 391208 396213 400213 400210
      400199 406194 402188 402185 404184 410178 414179 417182
      416186 414188 416195 411199 408205 405212 409213 413213
      415214 414217 413220 411225 413229 418225 418234 429232
      435230 439224 445221 447219 444217 437215 434216 430215
      427200 428193 430188 431184 429182 426180 430176 432174
      432171 428165 426163 425158 424152 423149 424147 425144
      427141 428142 432149 435159 435162 437165 440166 443164
      448164 447171 450178 449185 451188 457187 462183 466178
      468169 467155 467141 463142 458142 455140 453137 451136
      449140 446142 444142 443139 441133 437129 428118 429114
      433114 436112 439113 449110 450116 452117 456120 459117
      458114 460112 464112 465109 469110 467117 464119 465124
      467126 471127 475129 477118 478109 476100 474091 473088
      474084 473078 478064 478054 480042 478032 478022 477998
      479987 479984 482980 487966 489957 491948 494927 497907
      497901 493894 491886 488879 488874 486869 485864 485859
      485854 487849 486840 488821 489799 490779 490759 492741
      493736 493729 495722
 0.01 439251 440246 437244 433241 428237 426237 424240 400239
      397240 394239 389235 383232 378228 369213 366209 360210
      353208 348205 338198 337204 340209 348217 358225 368233
      372234 374237 378238 401250 406253 413255 419255 424254
      433254 439251
 0.01 420219 422217 421215 419216 419214 418211 416213 417215
      419216 419218 420219 420219
 0.01 423131 421126 420122 416122 411123 411126 412128 416130
      416132 410132 403132 402134 402138 406139 409138 415139
      416146 418144 419140 418137 419133 423131
 0.01 386111 387109 386107 384108 384109 383111 384111 385112
      386111
 0.01 372116 371114 370113 369112 368113 367115 369116 371117
      372116
 0.01 343180 345171 345167 343165 338162 333163 327160 322158
      319157 317158 314159 315161 317166 322170 328172 334176
      338179 343180
 0.01 350123 348122 346122 346123 346124 348124 350123
 0.01 342856 342853 340854 338854 338856 340858 342856 342856
 0.01 333073 331072 329071 327071 326072 327073 329073 331073
      333073
 0.01 326904 321899 322896 320893 307884 303878 301878 299882
      293887 289888 285887 282885 277885 272890 274894 276896
      279898 284898 287896 289896 290898 288906 299914 304914
      306919 308924 312920 312917 314912 317910 326904
 0.01 310154 310152 310151 308151 308153 308154 310154 310154
 0.01 298800 296798 294799 294801 296801 298800 298800
 0.01 291793 291789 289787 289785 287783 285781 283781 283785
      283790 282794 282796 284798 286798 288797 290795 291793
 0.01 292952 292951 290951 290952 288953 288954 287956 286956
      286958 286960 285962 284964 285965 286964 287964 288962
      289960 290958 290956 292954 292952
 0.01 283972 283970 283968 283966 282966 281967 280968 279969
      277970 275970 274972 273972 273974 274975 275975 277975
      279975 281974 283973 283972
 0.01 272810 268798 262798 259800 255801 250803 246798 240789
      236786 233785 230786 227791 226797 230811 231818 231826
      233833 235838 237845 240849 247858 251861 256864 258865
      263865 270864 271859 268855 260848 255836 252824 253819
      254816 253812 257811 259812 259815 260820 261821 265823
      266815 272810
 0.01 248002 248998 247996 246994 244991 241990 239989 236989
      234991 232993 232997 233000 234003 236005 238006 240006
      244004 245003 248002
 0.25 466749 466742 464736 460725 455718 449713 447710 442709
      440712 438716 436722 432724 425727 420728 419732 419739
      417744 414751 413758 415764 416769 413773 410782 406791
      404801 402824 401836 399846 393866 386882 377899 367913
      362920 359923 354925 350932 346940 343941 340945 336954
      331962 326968 316979 309983 301989 295995 293999 293004
      295008 299009 303008 306006 329982 332980 337980 344981
      347980 351977 356971 363968 368968 373968 382972 387972
      391970 396964 401955 411942 417935 423928 429925 432922
      435921 443923 449924 453923 459915 462905 464896 464890
      466886 469882 470876 470868 469861 464847 464835 463822
      462808 463798 465788 465782 465775 464769 465761 466749
 0.25 449672 447657 444654 442653 435652 429653 424657 421671
      418678 417686 418696 419701 419706 419715 422722 430711
      438700 442694 445688 448687 446684 447679 449672
 0.25 464873 464871 464870 464871 463873 464875 464873
 0.25 453008 454991 453977 454972 454964 451964 448968 443976
      440979 436981 433984 430989 428993 427998 427011 427018
      425025 424031 423034 424036 423040 421039 412044 404048
      400049 397053 395057 391060 374051 367051 362053 358053
      356055 355062 356067 358069 367074 372082 374087 377091
      383090 383093 386093 389090 390088 389086 388084 391085
      394090 401095 406098 408100 409098 414090 417076 424072
      428068 430063 430059 427053 426048 425043 429041 434041
      437040 441036 443031 445024 450016 453008
 0.25 396099 395097 394096 393098 394099 395100 396099
 0.25 392119 392117 392116 390116 389116 388116 387117 386118
      385119 384120 384121 386122 388122 390121 391121 392120
      392119
 0.25 393920 394917 392915 391916 390918 389919 389920 388922
      389924 389925 390924 391924 392922 393921 393920
 0.25 382135 382133 382131 382129 381128 380127 379126 377127
      375127 374129 374132 374133 375134 376135 378135 379135
      381136 382135
 0.25 368187 366186 364185 362185 361186 362187 364188 365189
      367189 368187
 0.25 378098 378096 378094 377096 377098 378099 378098
 0.25 380060 379059 378058 377057 375057 374056 372057 371057
      371059 372059 373060 375061 377061 379061 380060
 0.25 365121 363120 362121 363121 365121 365121
 0.25 349114 345105 345099 342094 337084 331078 328079 327082
      326087 326092 322095 322099 319103 316106 317110 323110
      326109 329111 332114 338116 344116 349114 349114
 0.25 343061 341059 339058 337058 336057 332055 330055 327055
      326057 328059 330060 334061 336062 339064 341063 343061
 0.25 303099 303097 302096 300095 298095 296095 295096 296097
      298098 299099 301099 303099 303099
 0.25 291094 288084 283078 276072 269068 260064 257063 253064
      252069 252074 257081 262086 270091 274093 280094 291094
 0.25 242821 242819 242817 240816 240817 240819 240821 241823
      242821
 0.50 454752 453746 452743 449740 445739 440741 435743 432742
      429740 426741 424746 424752 425758 427761 429767 428772
      427776 425779 422780 419779 415780 411788 409798 408808
      406816 405824 404834 402844 398860 391876 385890 378906
      375911 370916 365923 361930 356929 353930 353936 350945
      342947 339955 337962 337969 339973 342973 354965 356962
      360961 364959 367957 370951 373941 378928 383920 387913
      391908 395906 398906 401908 401914 398922 396929 393938
      391947 387954 387960 389962 393960 395957 403944 407938
      410931 414923 419919 424914 429905 432899 435891 437883
      437873 440864 444856 448850 450839 454822 455811 455800
      454790 454784 453779 451770 451762 454752
 0.50 406058 407056 406055 404054 402055 402056 401058 402060
      402061 404061 404060 405059 406058
 0.50 402072 401069 398067 394067 393066 389065 388068 387072
      387074 388077 390079 392080 394080 397078 399076 401074
      402072
 0.50 381083 383076 381072 379067 377064 372062 368059 366060
      365063 367068 369070 372074 374079 375083 378084 381083
      381083
 0.50 374053 372052 370052 368053 367054 366054 366056 366058
      367057 368056 370055 371055 372054 374053 374053
 0.50 346112 346111 345109 344107 343105 341106 340107 340109
      340110 341111 342112 344113 346112 346112
 0.50 342100 343098 342096 342095 340093 338093 337093 336095
      335097 334099 334100 335101 336103 337103 339104 341102
      342100
 0.50 334110 334108 333108 332110 333111 334110
 0.50 335088 336086 335086 334084 333084 332083 330083 330084
      330086 331088 333090 335090 335088
 0.50 334058 332057 330057 328057 328058 330058 332058 334058
      334058
 0.50 310996 310994 309994 308995 306995 305996 304997 302998
      300999 299000 299002 300003 302002 304001 306001 307000
      308000 309998 310997 310996
 0.50 281086 281082 280080 276075 272073 267069 262066 258065
      255067 254069 255075 258080 262084 267087 273089 279088
      281086
 1.00 444817 445810 443805 440801 439798 442791 441781 441775
      440768 437772 436776 433783 428792 424801 422805 420808
      413825 411828 409833 407842 404853 401861 387895 385902
      388903 390902 393900 406890 411884 417878 420875 423879
      424884 424891 421900 424899 426896 430876 432864 436857
      439847 436846 434848 431851 428848 428841 428836 429831
      431828 433825 437822 440825 442824 444817
 1.00 438758 437756 436756 435755 435756 435758 436758 437759
      438758
 1.00 377073 377071 377069 376068 375066 373064 372064 371064
      370063 369064 371066 371067 373068 373069 374071 374072
      375073 376075 377073
 1.00 361943 360941 359939 358938 357938 355938 355941 355943
      355944 356945 357947 359947 361945 361943 361943
 1.00 272083 273079 271077 270075 267072 265071 263070 260069
      258071 258072 259076 261078 263080 264081 266082 270084
      272083
 1.50 417853 417846 416839 413840 411843 407852 403862 400870
      396878 394883 395889 399887 402883 407875 411868 415859
      417853
 2.00 404873 404871 403869 402871 401871 401873 400875 400876
      399878 400879 401878 402876 404873 404873

$$





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