Quantitative Precipitation Forecast
Issued by NWS

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831
FXUS04 KWBC 270702
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
302 AM EDT WED APR 27 2016


PRELIM DAY 1 QPF DISCUSSION
VALID APR 27/1200 UTC THRU APR 28/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...WEST COAST/GREAT BASIN...

ENERGY DIVING SEWD ALONG THE PAC COAST IS FCST TO CLOSE OFF TOWARD
SRN NV/NW AZ BY THUR MRNG.  THE ASSOCD HEIGHT FALLS AND ASSOCD PAC
MSTR/MID LEVEL INSTABILITY WILL SPREAD LIGHT TO MODERATE PCPN ACRS
THIS REGION..ESPECIALLY THE SRN GT BASIN INTO THE WASATCH.   12Z
EC WITH A SLIGHT DRY OUTLIER ACRS THE GT BASIN/WASATCH BUT
REASONABLY SIMILAR ELSEWHERE.  THUS MAIN ADJUSTMENT WAS TO GO
TOWARD THE SLIGHTLY WETTER CONSENSUS AS MID/UPR LOW BECOMES BETTER
ORGANIZED OVER THE SRN GT BASIN WED NIGHT.


...REGARDING UPR LOW OVER THE CNTL U.S...

WHILE OVERALL MASS FIELD FCSTS ARE REASONABLY SIMILAR WITH THE
HANDLING OF THE UPR LOW LIFTING NWD INTO THE MO VALLEY..LOTS OF
DETAIL DIFFERENCES EXIST WITH VARIOUS VORTS ROTATING AROUND THE
MEAN CENTER WHICH HAVE AN IMPACT ON PCPN PLACEMENT AND AMOUNTS
ESPECIALLY EAST OF THE LOW CIRC.  STG 85H/7H THETAE ADV AROUND THE
NORTH SIDE OF THE CIRC WILL SUPPORT A DECENT COMMA HEAD PCPN BAND
ESPECIALLY TO THE NORTH AND WEST SIDE FIRST HALF OF PD BEFORE
SIGNIFICANT DRY SLOT WRAPS NWD THE THE MID MS VALLEY.  THE 12Z EC
WAS PERHAPS A LITTLE SLOW WITH DRY SLOT THRU IA SO PERHAPS A
LITTLE TOO ROBUST AND WIDESPREAD OF HEAVIER QPF AMOUNTS THERE...
OTHERWISE...THERE IS DECENT MODEL CONSENSUS WITH 1 TO 2 INCH RAINS
ACRS THE ERN HALF OF SD SWD INTO CNTL NEB.

FARTHER EAST...STGLY DIFFLUENT UPR JET PATTERN ACRS PARTS OF THE
MIDWEST WILL PRIME REGION FOR POTENTIALLY HEAVIER RAINS ESPECIALLY
LATER WED/WED EVENING WITH MODEST SWLY MSTR FLUX AHEAD OF CNTL
U.S. COLD FRONT FEEDING INTO QSTNRY E/W FRONT.  STG INSTABILITY
DVLPG TO THE SOUTH OF THE FRONT AND IN ADVANCE OF MID LEVEL DRY
SLOT WILL HELP SUPPORT AN INCREASE IN SHWER/TSTM ACTIVITY.  THERE
IS A DECENT SIGNAL IN THE HI RES MODELS SUPPORTING HEAVIER RAINS
ACRS SRN IL INTO SRN IN/WRN KY WHICH IS ALSO SUPPORTED BY SEVERAL
GLOBAL MODELS..THOUGH THE LATTER MAY BE A TAD TOO FAR NORTH WITH
THE HEAVIER AMOUNTS.  STORM PROPAGATION VECTORS SUGGEST ANY
ORGANIZED MCS THAT MAY DVLP HERE COULD BE SLOW MOVING THRU THE
AFTN/EARLY EVENING PROVIDING SOME THREAT OF RUNOFF CONCERNS.

ACRS ERN TX INTO THE LOWER MS AND TN VALLEYS...BOTH THE HI RES ARW
AND LATEST HRRR RUNS REALLY ACCELERATE SQLN ACRS THE SRN PLAINS
E/SEWD AS COMBO OF COLD POOL DYNAMICS AND INCREASING MID LEVEL
FLOW SOUTH OF THE UPPER TROF SUPPORT THE CONTINUED PROGRESSION OF
THIS LINE.  THESE SOLNS ARE WELL EAST OF MOST OF THE GLOBAL MODELS
THOUGH THE CANADIAN GEM HAS GONE TOWARD THE QUICKER SOLN.  CURRENT
TRENDS CERTAINLY SUPPORT THE FASTER SE PROGRESSION AND FOR THE
MOST PART HAVE FOLLOWED A BLEND OF THE HRRR/ARW AND CANADIAN GEM
WITH TIMING AND QPF AMOUNTS.  THE SQLN IS FCST TO REMAIN FAIRLY
ACTIVE THRU PARTS OF THE LOWER MS VALLEY THIS MRNG BEFORE
WEAKENING WITH SOME 1 TO 2 INCH AMOUNTS PSBL OVER PARTS OF SRN
LA/SRN MS/SW AL.  OUTFLOW REMNANTS WILL ACT AS THE EFFECTIVE FRONT
OVER THIS REGION AS DEEPER MSTR WILL FOCUS EAST OF THE OUTFLOW
UNTIL LATE WED/WED NIGHT WHEN A SECONDARY SURGE OF HIER PWS WITH
STRENGTHENING SWLY 85H JET SUPPORTS AN INCREASE IN SHWRS/TSTMS IN
ADVANCE OF TRUE FRONT ADVANCING EWD ACRS THE LOWER MS VALLEY.
AGAIN..A GENL BLEND OF THE WRF ARW/HRRR AND CANADIAN GEM WAS
PREFERRED WHICH RESULTED IN A FASTER PROGRESSION OF HEAVIER RAIN
AXIS FROM CONTINUITY.

...OH VALLEY/MID ATLC...

REMAINS OF A EARLIER WELL DEFINED MCS THAT MOVED ACRS PORTIONS OF
THE MIDWEST/LOWER OH VALLEY WILL CONTINUE EWD ALONG AND JUST SOUTH
OF E/W COLD FRONT WITH GENL WEAKENING TREND THIS MRNG BEFORE
ADDITIONAL STORMS DVLP SOUTH OF THE FRONT AND ALONG OLD OUTFLOW
BNDRIES THIS AFTN WITH DAYTIME HEATING.  THE STGR INSTABILITY
GRADIENT AND POOLING OF 1.5" OR GREATER PWS ACRS SRN VA/NC BORDER
REGION WOULD SUGGEST LOCAL QPF MAX ACRS THAT REGION WITH A BLEND
OF THE GFS/NAM AND HI RES MODELS SUPPORTING .50 INCH OR GREATER
AREAL AVG AMOUNTS THOUGH EMBDD HEAVIER RAINFALL AMOUNTS IN EXCESS
OF 2 INCHES WILL BE PSBL.

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

SULLIVAN

24HR QP VT 28/12Z
 0.01 511295 492282 478271 474267 469267 465267 459266 456267
      450264 440261 421255 414253 410252 407253 388248 378246
      373243 370241 367237 364232 365230 370229 373228 373225
      370223 361219 356216 353213 347205 347201 344196 343193
      342188 335181 332178 328177 325175 319173 311169 303160
      302157 305156 308155 313156 315159 318159 324160 336163
      346164 351164 354160 354154 352151 345146 341138 338133
      338126 336117 337108 343105 351105 356106 362105 366104
      368101 371094 373089 372082 370070 364061 357056 357051
      360049 369046 371043 376042 385044 394047 399051 408053
      412055 413060 414071 415073 411075 409080 408082 409084
      412091 417097 418099 421098 423093 426084 431085 433081
      432069 432058 430054 430046 428041 425037 423032 421025
      417019 411016 402012 396008 393005 388004 384004 381002
      378001 375998 374994 375988 378977 385970 382961 380950
      375928 357922 350924 342927 336931 331935 325940 319946
      314952 308956 301964 298966 292968 284971 281973 278971
      272966 271952 272947 274942 277934 279930 275928 274923
      274918 278902 282893 286886 288878 292872 297863 298856
      300851 305845 312841 319834 326829 330828 333828 334826
      337815 341798 342794 342790 344781 346772 346761 347741
      350736 351731 355721 357711 359702 360698 362693 365683
      368680 374678 377677 380681 384688 386701 388721 388727
      389734 390741 391747 399760 404771 409782 417799 425820
      429827 435835 437840 437844 441853 446871 451894 453902
      457913 464942
 0.01 464942 466953 469962 475982 477992 481998 485005 488012
      495030 499039 502049 504057 507067 511082 514095 515105
      516111 515118 515124 513130 508146 506148 503147 497143
      490137 487139 484138 476141 476146 480149 508162 516178
      512182 508183 504183 497182 490178 483176 481174 477172
      472171 469168 463162 459163 459167 464174 465178 464181
      460188 455191 450191 447194 449206 452209 454210 456210
      463208 471207 477204 481199 486193 490188 500191 501195
      501201 501207 500209 494215 482217 478217 475218 468218
      460220 457220 456222 455223 451231 451234 454234 457233
      459232 460235 455238 452239 452242 455246 460247 479254
      489257 492256 497257 505260 509261 512259 516253 521248
      526233 527228 528228 533230
 0.01 487647 486641 484638 482635 479633 473634 464637 461638
      458641 456644 454648 457655 459659 461659 467662 475659
      478658 481655 486650 487647
 0.01 492713 490707 485705 480701 477699 471696 468697 467702
      471708 473713 477718 480720 483719 489717 492713
 0.01 451088 451086 450085 449083 448082 447081 446080 444080
      444079 443078 441077 439078 437077 436078 436081 437083
      439085 440085 442086 444086 445087 447088 449088 450088
      451088
 0.01 336800 334795 331796 327799 325802 323806 319809 311812
      293811 273811 261812 253810 256814 262819 269824 276827
      285830 293831 305830 315828 319826 322823 326817 331809
      334805 335802 336800
 0.25 493084 494078 492074 489067 486062 482059 478054 476045
      474038 473030 473020 471014 468004 460979 456960 453946
      450929 445914 440904 437899 435892 432879 431873 428867
      424861 419857 414854 412848 408834 403818 401813 398809
      394806 392801 390794 389784 390778 390774 389769 386763
      384760 383763 383772 382778 380781 377781 375770 374763
      374757 373749 369746 367744 364744 362748 357758 354768
      354779 357787 360802 360806 358810 355815 347822 336840
      332844 329847 320853 308861 303865 300868 296881 290893
      286903 283914 286923 282935 281943 281951 284957 288958
      293955 297950 304940 310934 321930 330924 338917 347906
      356901 360899 363901 368904 374906 379909 390926 391933
      390938 393944 397947 402952 405959 407965 406971 403977
      397978 393978 391980 392987 395991 399995 406001 423015
      433024 440033 447044 456052 464059 469063 473063 474064
      475067 476073 479079 483082 489085 493084
 0.25 452161 451156 448153 446150 444146 441142 437143 435147
      436150 438154 442156 444159 447163 452164 452161
 0.25 416232 415231 413231 415232 416232
 0.25 409112 411105 410099 407098 404100 400106 394110 385112
      382114 379117 378128 382127 387129 388133 385136 382138
      383142 383149 376155 374158 374163 378166 383167 389163
      392160 394156 397147 401137 400129 401122 403118 406116
      408113 409112
 0.25 389199 388193 385190 382187 379184 376181 372179 367177
      364180 365184 367188 371191 374194 378196 382199 387200
      389199
 0.25 375726 375722 374717 374713 372710 369709 367712 366717
      366719 366723 368728 369730 370732 374731 374728 375726
 0.25 366135 365133 365132 364132 362131 360132 360134 361135
      363136 365136 366135
 0.25 353188 351188 353188 353188
 0.25 359874 358865 357861 355859 350859 348862 344868 341873
      337880 333887 332890 334893 336895 340896 346893 351887
      355881 358879 359875 359874
 0.50 464033 466023 465013 462000 455974 452962 449950 448938
      447931 445928 444922 443920 439915 436916 432912 419895
      416884 418883 420878 418872 415870 407866 403861 401854
      400846 398841 392831 388827 385822 379818 375806 372802
      369804 366809 364816 340843 338849 334850 326857 318861
      313862 308866 304870 299879 290900 287910 289914 289918
      285937 284946 285950 287952 291952 294948 308933 323924
      330918 333915 335910 334908 331907 325906 321902 319898
      320894 322889 329881 334873 337865 338852 347848 352844
      358842 361842 363845 363850 366867 366876 365883 365887
      367892 372899 380902 384906 387911 395918 398922 399926
      398929 397935 400941 403945 407949 411952 413956 412960
      413965 414969 412973 410977 407980 403983 401985 400989
      404994 412001 419006 429011 436017 442023 455037 458040
      461042 463040 464033
 0.50 408107 409105 408103 408101 406102 406104 405105 404107
      403108 403109 401111 400113 401114 402113 403112 404111
      405110 406109 407108 408107
 0.50 371799 369791 365784 367781 369779 368768 366759 364758
      362760 360768 359778 360786 363794 367800 371799
 1.00 458020 459011 459002 455991 447969 442958 437949 424933
      419931 414933 412935 412938 415940 424946 428949 430954
      430961 428966 423974 418977 414981 408989 412994 417996
      425001 435005 442010 450019 454022 458020
 1.00 407905 406897 402892 400889 399885 397876 396867 393860
      390854 386849 377848 373855 372862 370870 370876 370884
      372890 375893 378894 383896 388900 392906 397910 403912
      407905
 1.00 325872 323868 319868 312872 308874 304877 302884 299889
      298894 294901 294905 296907 301907 297913 293921 290930
      289935 289939 290942 294942 297939 308927 314920 314915
      312912 309908 305906 304903 306900 316886 322879 324875
      325872
 1.50 447995 446988 443982 440976 438971 435970 433973 432980
      429986 426990 427995 432998 439998 445998 447995
 1.50 388872 387865 385863 382860 380859 377864 375867 373873
      373878 374882 377886 380886 382882 384878 386874 388872
 1.50 307920 306916 304915 301916 299917 297920 296922 295924
      295929 297930 301930 303928 305925 306922 307920

$$





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