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Quantitative Precipitation Forecast (QPF) Discussion
 
(Caution: Version displayed is not the latest version. - Issued 0700Z Feb 22, 2018)
 
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Abbreviations and acronyms used in this product
 
Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White


QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
200 AM EST THU FEB 22 2018


PRELIM DAY 1 QPF DISCUSSION
VALID FEB 22/1200 UTC THRU FEB 23/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

NORTHEAST TX---LOWER MS VALLEY---LOWER TN VALLEY---OH
VALLEY---NORTHERN MID ATLANTIC INTO SOUTHERN NEW ENGLAND

ANOTHER ROUND OF WIDESPREAD HEAVY TO EXCESSIVE PRECIPITATION
LIKELY FOR THE UPCOMING DAY 1 TIME PERIOD FROM NORTHEAST TX---INTO
PORTIONS OF THE LOWER MS VALLEY---LOWER TN VALLEY AND INTO THE OH
VALLEY.  THERE IS EXPECTED TO BE NO BIG CHANGES TO THE BROAD
SOUTHWEST MID TO UPPER LEVEL FLOW FROM THE SOUTHERN PLAINS
NORTHEASTWARD INTO THE LOWER TO MID MS VALLEY---GREAT LAKES AND
INTO THE NORTHEAST.  PW VALUES IN THIS SOUTHWEST MID TO UPPER
LEVEL FLOW WILL REMAIN HIGHLY ANOMALOUS WITH VALUES 3-4+ STANDARD
DEVIATIONS ABOVE THE MEAN.  THE CURRENT AXIS OF HEAVY PRECIP FROM
NORTHEAST TX INTO THE LOWER MS VALLEY---LOWER TN VALLEY INTO THE
OH VALLEY IS EXPECTED TO WEAKEN AFTER 1200 UTC WITH A CONCENTRATED
AREA OF PRECIP MOVING OUT OF THE UPPER OH VALLEY---ACROSS THE
NORTHERN MID ATLANTIC AND INTO SOUTHERN NEW ENGLAND DURING THE
FIRST HALF OF THE PERIOD.  PRECIP IS THEN EXPECTED TO REFOCUS IN
AN AXIS FARTHER TO THE NORTHWEST FROM THE EARLY MORNING ACTIVITY
AS LOW LEVEL FLOW RE-STRENGTHENS OUT OF THE SOUTH AND INTO THE
FRONTAL BOUNDARY STRETCHING NORTHEAST FROM NORTHEAST TX ACROSS THE
LOWER MS VALLEY AND INTO THE OH VALLEY.  DIFFERENCES IN MODEL QPFS
REVOLVE AROUND THE LATITUDE OF THIS NEXT MAX AXIS.  DAY 1 QPF
LEANED TOWARD THE SOLUTIONS THAT WERE FARTHER TO THE SOUTH AND
EAST---TRENDING APPROX 40-60NM FARTHER TO THE SOUTHEAST FROM THE
PREVIOUS FORECAST.  THERE IS A LOT OF RUN TO RUN VARIABILITY WITH
THE QPF DETAILS AT THE SHORTER FORECAST INTERVALS.  WHILE THE
SECOND ROUND OF PRECIP WILL LIKELY OVERRUN THE ABOVE MENTIONED
FRONTAL BOUNDARY FAIRLY FAR TO THE NORTH---WPC CONTINUED TO FAVOR
THE SOLUTIONS THAT WERE FARTHER TO THE SOUTHEAST CLOSER TO THE
GREATER INSTABILITY NEAR THE FRONTAL BOUNDARY.  THERE WILL LIKELY
BE ANOTHER ROUND OF POTENTIALLY TRAINING CONVECTION BETWEEN
0000-1200 UTC FRIDAY FROM NORTHEAST TX---NORTHEASTWARD INTO
AR---NORTHWEST MS---WESTERN TN---FAR SOUTHEAST MO INTO THE LOWER
OH VALLEY. 



                                                     
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 23/12Z
 0.01 499909 499897 498886 495867 494861 492858 488851 477841
      471840 465838 459837 456837 454839 449843 444847 437848
      432845 428831 424822 426813 433777 437743 438728 439720
      437712 435706 434701 433692 430674 428663 427660 426653
      424646 423643 416647 411644 403646 397648 392652 385654
      382661 378666 376673 373687 370703 370724 372734 374743
      372758 370763 367768 361783 358796 360807 360810 363809
      367811 366816 364824 357840 351853 343865 337876 331885
      327890 324896 321901 319903 316903 303899 294898 287897
      288908 293912 296914 299915 299923 296931 292934 288939
      285941 279952 276963 270967 264970 258973 257981 256992
      253995 248995 241996 238997 238001 240009 245012 250014
      255014 263015 265015 268013 272008 278006 286006 294004
      309001 313002 317003 324005 339002 348996 356988 369992
      379997 379015 382024 384023 389023 395020 399019 401022
      404040 405044 408046 414045 422036 429028 474997 482988
      484986 484982 484972 484961 487954 489946 491937 493929
      496921 499909
 0.01 464224 465219 465215 463214 453215 447216 444215 441212
      433203 430199 423197 418189 413186 412182 415178 419176
      436180 442177 441183 443187 446188 448190 450195 452197
      455194 458190 463181 464173 460174 460166 462161 464155
      463148 461143 457138 453124 444120 438112 436106 435102
      430092 428087 427084 427080 428071 425067 422067 422070
      421080 420083 421085 421088 423090 426094 427097 425100
      417105 413107 411103 410097 408093 405095 401098 398097
      398093 400085 402079 406074 411076 413076 415073 415069
      415061 408056 399053 388047 387051 382049 376048 370048
      365049 361051 355055 354063 356069 356072 360073 366074
      369076 372080 372085 371090 370097 367103 363105 356113
      351112 348109 342107 343112 346116 347121 344124 345129
      348139 356136 362137 366136 370137 372139 373144 374148
      376149 380154 386157 387161 386165 384172 380174 381182
      377184 371181 365180 359180 350182 346186 343190 338201
      339206 347208 351212 354215 360222 363225 368227 372230
      376235 383241 387246 393247 406252 419253 428251 435247
      439236 444234 450234 458229 461227 464224
 0.01 475111 475106 474104 472102 468101 466102 464107 464109
      465112 464114 463119 463122 467123 470124 472123 473118
      473113 475111
 0.01 404224 403221 400219 395217 390213 384210 374204 368201
      366196 364193 361192 354190 352190 350193 348197 349201
      350203 352205 359208 364210 369214 376216 379220 382221
      386222 391222 397225 400226 402225 404224
 0.01 395105 395101 392099 389094 383095 378098 374102 371107
      367113 370113 372111 377109 380109 382110 387111 393107
      395105
 0.01 381063 381060 381059 379059 377058 375058 373058 372059
      371059 372060 373060 374062 375062 377062 378063 380063
      381063
 0.01 345182 345173 343166 338164 334163 327160 322160 320161
      314163 317168 324174 331176 335178 337180 342185 345182
 0.01 297809 296805 295803 294801 291799 288799 286797 284798
      281800 281802 280805 281807 283808 286809 288810 291810
      293812 295811 297809
 0.01 275828 272816 268806 267799 264796 257797 253799 246805
      239811 239819 242823 245828 248825 250819 252818 254823
      257828 262829 267830 273829 275828
 0.25 481884 480876 478872 476872 471878 468877 462879 455882
      451887 448892 444898 440905 438908 434909 429909 421911
      418912 416915 414922 412928 410937 409943 411947 412950
      416951 421954 425958 432961 440971 443977 444987 447994
      452993 459979 462974 464967 466958 467952 469949 472943
      474935 477918 479910 480899 481890 481884
 0.25 441154 441151 440150 438150 437151 436152 436153 438154
      439154 441154
 0.25 428743 428732 427719 425712 423710 420709 415710 408721
      405727 401734 399741 398751 397762 394771 393774 390776
      387783 385790 384797 384808 383818 378824 370828 357852
      354859 351866 343882 336894 330905 319915 312931 306944
      300956 297962 294970 293975 294980 296983 299985 302986
      306987 314986 326980 331975 338973 341971 344967 346958
      351954 355949 359944 363937 371926 374922 376918 381912
      389900 391894 392885 394877 393869 400852 404846 409840
      411835 413826 417811 419799 421790 425774 428757 428743
 0.25 415241 415239 414237 412236 411235 409234 407234 405234
      404235 403235 401237 401239 401241 401242 402243 404244
      406244 407244 408244 409243 411243 412242 413242 415241
 0.25 399211 398200 399195 396190 396195 394200 389199 386196
      378189 368183 361183 357185 364189 372196 380202 388208
      394211 399211
 0.25 386086 385081 381079 379076 378070 376066 373063 368062
      368066 371069 373073 375078 379080 382083 384086 386086
 0.25 343173 343171 343169 341168 340170 341171 341173 342175
      343173
 0.25 334169 334167 334166 332165 330164 329164 327165 327168
      328169 330170 332170 333170 334169
 0.50 420759 420749 418743 416742 411742 408745 406750 403763
      403771 400778 396791 393800 391808 390816 389824 386838
      384844 380850 373863 369869 365874 362877 362868 365862
      367858 364857 358861 356864 354868 352875 349879 342890
      335901 331907 326912 322917 319924 316937 310947 305955
      303961 302965 302969 308971 319968 332963 338960 343955
      347950 350945 355934 358927 362923 368916 371910 385888
      392857 398846 404834 406828 407817 411811 414804 417789
      420775 420759
 0.50 378196 377195 377194 376192 375191 374190 373189 372188
      371187 369186 368185 366185 365186 366188 367189 369190
      371191 372192 372193 374194 375196 377197 378196
 0.50 376073 377071 376069 375066 373064 371063 370063 369064
      370066 371067 373068 374071 374073 376074 376073
 1.00 387854 386852 384853 379859 373870 369875 365881 357890
      348899 343902 346895 346892 344893 340899 333908 329914
      326921 322934 319941 317945 319946 320949 321954 321957
      323956 327955 330953 336949 340945 343940 350928 357916
      371896 378883 382870 387854
 1.50 376877 373877 370880 367886 361892 356896 347906 337916
      333922 329928 326936 326939 329939 342932 347927 351921
      359910 367897 371890 374883 376877
 2.00 361903 358901 353905 349908 345912 341917 337921 336928
      343928 346924 350919 353914 356910 359905 361903