Quantitative Precipitation Forecast
Issued by NWS

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337
FXUS04 KWBC 280701
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
301 AM EDT THU APR 28 2016


PRELIM DAY 1 QPF DISCUSSION
VALID APR 28/1200 UTC THRU APR 29/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

UPPER MS VALLEY---LOWER LAKES---UPPER OH VALLEY---CENTRAL
APPALACHIANS INTO THE MID ATLANTIC

THE LEAD CLOSED LOW MOVING INTO THE UPPER MS VALLEY THIS MORNING
WILL CONTINUE TO WEAKEN...SHEARING EASTWARD ACROSS THE UPPER MS
VALLEY INTO THE GREAT LAKES DAY 1.  WITH THE OVERALL WEAKENING
TREND TO THIS LEAD SYSTEM---PRECIPITATION AMOUNTS AND INTENSITIES
TO THE EAST OF THIS SYSTEM LIKELY TO DECREASE FROM THE UPPER MS
VALLEY INTO THE LOWER LAKES.  STRONGER ISENTROPIC LIFT OVER THE
STATIONARY FRONTAL BOUNDARY DRAPED FROM THE OH VALLEY INTO THE
CENTRAL APPALACHIANS AND SOUTHERN MID ATLANTIC WILL SUPPORT
HEAVIER PRECIP TOTALS ACROSS THESE REGIONS DAY 1.  HEAVIEST TOTALS
LIKELY IN THE VICINITY OF THE FRONTAL BOUNDARY OVER EASTERN NC
WHERE THERE MAY BE A REPEAT OF THE CURRENT ACTIVE CONVECTION ALONG
THE WEST TO EAST ORIENTED FRONT LATE THURSDAY AFTERNOON INTO
THURSDAY EVENING.  WHILE FFG VALUES ARE CURRENTLY HIGH IN THE
VICINITY OF THIS FRONT...CURRENT CONVECTION AND POTENTIAL FOR
ADDITIONAL CONVECTION ALONG THE BOUNDARY MAY POSE ISOLATED RUNOFF
ISSUES---ESPECIALLY WHERE TRAINING IN A WEST TO EAST DIRECTION
OCCURS.

SOUTHEAST INTO THE CENTRAL GULF COAST

LOW CONFIDENCE IN QPF DETAILS ALONG AND AHEAD OF THE FRONTAL
BOUNDARY PRESSING EAST SOUTHEASTWARD FROM THE LOWER MS VALLEY INTO
THE TN VALLEY AND SOUTHEAST.  THERE IS A WIDE SPREAD WITH RESPECT
TO QPF DETAILS AMONG THE LATEST GUIDANCE ACROSS THESE AREAS.
WHILE PW VALUES ARE ABOVE AVERAGE ACROSS THESE AREA---LARGE SCALE
FORCING IS WEAK.  WHILE THERE WILL LIKELY BE LOCALLY HEAVY TOTALS
IN THIS AXIS--CONFIDENCE LOW GIVEN THE AFOREMENTIONED SPREAD.  DAY
1 QPF DID GO TOWARD THE MODEL CONSENSUS FOR A MAX IN THE VICINITY
OF THE CENTRAL GULF COAST FROM EASTERN LA INTO FAR SOUTHERN
MS---SOUTHERN AL AND THE WESTERN FL PANHANDLE.

SOUTHWEST INTO THE GREAT BASIN AND CENTRAL ROCKIES

AS THE LEAD CLOSED LOW OVER THE UPPER MS VALLEY WEAKENS DAY 1--THE
NEXT IN THE SERIES OF AMPLIFYING CLOSED LOWS WILL PUSH FROM THE
SOUTHWEST EARLY DAY 1---INTO THE SOUTHERN ROCKIES AND SOUTHERN
HIGH PLAINS BY THE END OF THE PERIOD.  PRECIPITATION SHOULD REMAIN
CONCENTRATED INITIALLY TO THE NORTH OF THIS STRENGTHENING CLOSED
LOW ACROSS THE SOUTHERN GREAT BASIN IN A REGION OF A FAIRLY WELL
DEFINED COMMA HEAD/DEFORMATION PRECIPITATION BAND---EXPANDING WITH
TIME INTO THE CENTRAL ROCKIES IN A REGION OF INCREASING UPPER
DIFFLUENCE DOWNSTREAM OF THIS CLOSED LOW.    MODEL CONSENSUS IS
FOR A WIDESPREAD REGION OF MODERATE PRECIP TOTALS FROM NORTHERN
AZ--EASTERN NV INTO MOST OF UT---AND INTO CO---WITH ISOLATED HEAVY
TOTALS POSSIBLE---ESPECIALLY THROUGH THE WASATCH AND INTO THE
CENTRAL ROCKIES.  LATE SEASON HEAVY SNOWS POSSIBLE ACROSS THE
WASATCH AND INTO THE CENTRAL ROCKIES.  SEE THE LATEST QPFHSD FOR
ADDITIONAL WINTER WEATHER INFORMATION.

CENTRAL TO SOUTHERN PLAINS

INCREASINGLY UPPER DIFFLUENT FLOW AND STRENGTHENING LOW LEVEL FLOW
INTO AND OVER THE WEST TO EAST ORIENTED FRONTAL BOUNDARY OVER THE
SOUTHERN PLAINS WILL SUPPORT INCREASING PRECIPITATION COVERAGE
ACROSS PORTIONS OF THE CENTRAL TO SOUTHERN PLAINS.  THERE IS A LOT
OF MODEL DETAIL DIFFERENCES ACROSS THESE REGIONS---LEADING TO LOW
CONFIDENCE WITH THE QPF DETAILS DAY 1.  QPF DIFFERENCES ARE BOTH
WITH HOW FAR TO THE NORTHEAST PRECIP SPREADS INTO THE CENTRAL
PLAINS TO THE NORTH OF THE WEST TO EAST FRONTAL BOUNDARY---AND THE
DEVELOPMENT OF POTENTIALLY ORGANIZED CONVECTION CLOSER TO THE WEST
TO EAST BOUNDARY OVER THE SOUTHERN PLAINS.  DAY 1 QPF KEPT WITH
CONTINUITY IN SHOWING MODERATE TOTALS SPREADING NORTHEASTWARD INTO
THE CENTRAL PLAINS---WHILE SHOWING HEAVIEST PRECIP POTENTIAL
FARTHER TO THE SOUTH IN THE VICINITY OF THE WEST TO EAST BOUNDARY
FROM THE TX PANHANDLE---ACROSS NORTHERN TX/SOUTHERN OK.  STILL A
LOT OF TIMING DIFFERENCES HERE ALSO WITH HOW CONVECTION DEVELOPS.
 WITH A LOT OF INSTABILITY ALONG AND SOUTH OF THIS
FRONT...STRENGTHENING SOUTHERLY INFLOW INTO THE BOUNDARY AND VERY
DIFFLUENT FLOW DOWNSTREAM OF THE SOUTHWEST/SOUTHERN ROCKIES CLOSED
LOW---BELIEVE THERE WILL BE A GOOD CHANCE OF INCREASING CONVECTION
IN THE VICINITY OF THE FRONT FROM 0000-1200 UTC FRIDAY.  DAY 1 QPF
LEANED TOWARD THE IN HOUSE QPF MEAN WHICH SHOWED PRECIP PUSHING
DOWNSTREAM FASTER...CLOSER TO THE ECMWF AND GFS.  WHILE AREAL
AVERAGE PRECIP TOTALS WERE KEPT IN THE .25-.50"+ RANGE---THERE
WILL LIKELY BE HEAVIER TOTALS GIVEN THE POTENTIAL FOR ORGANIZED
CONVECTION IN THE VICINITY OF THIS FRONT.  RUNOFF ISSUE ARE ALSO
POSSIBLE IN THE VICINITY OF THIS FRONT...WITH A BROAD SLIGHT RISK
OF EXCESSIVE RAINFALL DEPICTED IN THE VICINITY OF THIS BOUNDARY.

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

ORAVEC

24HR QP VT 29/12Z
 0.01 529207 529201 529198 527191 525187 524182 518174 515170
      511166 515163 513158 511151 506143 502140 499136 495127
      494121 494117 490104 486097 481088 480082 480076 477065
      475054 471051 470043 469031 465003 462990 462984 461980
      461976 461970 460965 459952 455929 453901 448879 446874
      445866 444860 443853 441846 440838 437828 434796 433788
      432781 428769 427763 427759 425747 419726 416702 405685
      400676 394668 391667 390673 380677 376681 374685 372689
      368693 361694 357698 351704 347713 343720 334736 329743
      324749 314763 312766 310772 310776 310782 311788 317788
      317793 314798 312803 309807 304808 302811 295809 291807
      286809 281811 277813 278816 282818 289822 295826 298838
      300841 300847 295864 285881 283885 281890 282904 285913
      290921 297926 299929 303927 310922 312918 315913 320906
      323898 330880 340866 349851 361834 363832 365835 366843
      369853 372853 375852 383855 392860 396862 401863 404865
      407868 411877 414887 416899 422923 422935 422943 424947
      424955 426961 426966 424972 424978 422980 421978 419975
      415968 412960 409956 406953 396958 392959 386959 380954
      377953 373952 368951 365949 359947 356945 345932 339926
      332919 329918 326919 322921 317929 308946 308970 310975
      313979 315984 316989 302998 293007 292014 296017 303021
      306023 311022 316023 321025 342031 349031 354030 357028
      359029 360032 357054 357062 358067 360069 365070 368074
      370078 371082 371086 367092 364096 359097 353103 350108
      347105 341089 339086 335087 333091 334095
 0.01 334095 335103 337109 343119 341131 345136 346143 350149
      353155 357160 360163 366163 370167 374179 373185 370186
      365182 361183 360186 362187 370195 374198 378200 380197
      379194 382194 388197 389189 390184 392181 408166 418161
      419151 413150 412142 413136 417132 423129 427125 430119
      435114 437113 438115 443120 446117 450114 454115 454126
      452129 452134 445142 438136 438139 437142 438148 442152
      445155 447157 451163 452170 454176 459176 461178 466175
      471171 475172 477175 482179 482186 483191 482196 478200
      474200 473203 474207 481209 488209 493207 497205 501199
      503193 507196 512201 521210 524212 526211 529207
 0.01 497156 492153 491150 488144 485141 480141 475141 471143
      471147 474150 477153 480155 485158 489157 494157 497156
 0.01 450085 442076 439071 437068 438064 440063 442059 440052
      438038 436030 433023 430009 428003 426005 427007 429013
      429018 430023 430031 431038 434054 434062 435069 428068
      424065 419069 415073 412079 410084 410093 411100 413107
      414110 417110 423107 426103 429100 427096 426091 424089
      426086 427084 431085 440090 443089 446089 450085
 0.01 344178 345171 343167 340165 334164 329163 323162 321164
      322169 326170 330169 334168 338170 340175 343177 344178
 0.25 479127 478126 476126 475126 476127 478127 479127
 0.25 422818 422811 420804 418796 415788 415776 416765 414758
      413754 410746 406738 401730 398721 395716 393714 386712
      377713 370714 362719 358723 348737 337748 331754 327761
      325764 326768 334766 338766 338771 336781 337787 342794
      345796 350797 353793 354789 359803 373810 377817 383822
      390826 398823 406823 411827 416830 419832 420830 422818
 0.25 421844 421841 421844 421844
 0.25 407110 408103 402104 397098 394098 392103 386106 380108
      374114 372116 369116 359115 352115 350118 351122 355127
      362131 367136 374140 378140 381138 385133 391128 396124
      400118 405114 407110
 0.25 410052 409046 408040 403031 401026 400022 400007 399001
      399993 397987 393984 384983 376985 370987 366984 356981
      349977 346974 345967 345956 342946 337937 331932 327932
      323936 321941 320946 321954 323958 326966 330970 332975
      332985 329995 326005 322011 322014 325016 333019 339021
      345021 354019 360019 363023 366028 366033 366042 363046
      363052 363055 366056 372057 374061 371063 375082 381085
      384089 389091 392090 396087 398083 403074 408064 408055
      410052
 0.25 378766 379762 378757 376755 373754 371754 370756 370759
      370763 371768 371772 371775 373777 375776 377773 377769
      378766
 0.25 327842 322838 319838 313842 310845 306850 304855 300867
      297880 296887 298892 302895 306892 313884 319874 324863
      327857 326848 325842 327842
 0.50 407761 404753 401748 397742 392738 393746 396754 397765
      396775 390786 384789 381796 380799 381804 384810 389814
      394811 405804 408796 408792 407788 404779 404774 404769
      407761
 0.50 400051 399044 398040 396036 393033 388031 386028 382026
      379028 373033 369037 368041 367046 366049 367052 372053
      375054 382058 388059 391058 395056 398053 400051
 0.50 388120 388118 387116 385116 381116 379117 377119 375121
      373123 372127 373130 376131 378130 380128 382126 384124
      386122 388120
 0.50 380015 381007 380999 377995 374995 368996 363994 359990
      353989 347989 341991 338994 335999 333003 332010 334015
      340017 351015 356013 360010 363011 365013 367017 370019
      373018 377017 380015
 0.50 368786 367773 365761 362756 360754 356750 353751 351754
      349758 345767 342775 342781 345785 354780 358788 360794
      363798 366797 367793 368786
 0.50 343967 343959 341952 339947 336942 334939 330939 328941
      327945 329952 331958 333965 335971 337978 339980 341978
      342973 343967
 0.50 320855 320851 318849 313849 309854 307858 305865 304871
      302878 302882 303886 309883 312879 316873 318868 319862
      320855
 1.00 382047 381045 381044 380043 378043 377044 377046 378047
      379048 381048 382047
 1.00 364789 364782 363776 363769 361764 359761 355759 352762
      352766 353771 357772 360776 361783 363787 364789
 1.00 352004 353002 351000 349999 347999 346000 344001 343002
      343004 343006 344008 345008 347008 349007 350007 351005
      352004

$$





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