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Quantitative Precipitation Forecast (QPF) Discussion
 
(Caution: Version displayed is not the latest version. - Issued 0658Z Apr 24, 2014)
 
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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
258 AM EDT THU APR 24 2014


PRELIM DAY 1 QPF DISCUSSION
VALID APR 24/1200 UTC THRU APR 25/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

PACIFIC NORTHWEST---NORTHERN CA---NORTHERN GREAT BASIN AND
NORTHERN ROCKIES

THE LEAD AREA OF NORTHEAST PACIFIC HEIGHT FALLS MOVING TOWARD THE
PACIFIC NORTHWEST EARLY THURSDAY WILL PUSH THE ASSOCIATED FRONTAL
BOUNDARY INLAND INTO THE PACIFIC NORTHWEST/NORTHERN CA THURSDAY. 
ORGANIZED PRECIPITATION IN THE AXIS OF ABOVE AVERAGE PW VALUES
ALONG AND AHEAD OF THIS FRONT WILL BE FOLLOWED BY POST FRONTAL
ONSHORE FLOW  SHOWERS.  THE UPPER TROF OFF THE PACIFIC
NORTHWEST/NORTHERN CALIFORNIA COAST IS EXPECTED TO AMPLIFY TOWARD
THE END OF DAY 1 WHICH WILL ENHANCE UVVS FROM NORTHERN CA---INTO
SOUTHERN OREGON AND INLAND INTO NORTHERN NV AND SOUTHWEST ID LATE
THURSDAY INTO EARLY FRIDAY.  THE DAY 1 QPF LEANED TOWARD THE
HEAVIER QPF OF THE CMC GEM AND GFS NEAR THE END OF DAY 1.  
OTHERWISE---A BLEND OF THE NAM---SREF MEAN AND ECMWF WERE USED FOR
QPF DAY 1 ACROSS THESE AREAS, 

UPPER MS VALLEY/UPPER LAKES---SOUTHWARD THROUGH THE MID TO LOWER
MS VALLEY---LOWER OH AND LOWER TN VALLEYS

HEIGHT FALLS IN NORTHERN AND SOUTHERN STREAMS EXPECTED TO PUSH
EASTWARD IN TANDEM DAY 1 FROM THE NORTHERN AND SOUTHERN PLAINS
INITIALLY---EASTWARD INTO THE UPPER MS VALLEY/UPPER LAKES REGION
AND MID MS VALLEY/LOWER OH VALLEY BY THE END OF THE DAY 1 PERIOD. 
THIS WILL SUPPORT A FAIRLY WIDESPREAD REGION OF MODERATE TO HEAVY
PRECIPITATION POTENTIAL STRETCHING FROM THE UPPER MS VALLEY/UPPER
LAKES REGION---SOUTHWARD THROUGH THE MID TO LOWER MS VALLEY AND
LOWER OH VALLEY IN AN AXIS OF ABOVE AVERAGE PW VALUES---WELL
DEFINED BOUNDARY LAYER CONVERGENCE/UPPER DIVERGENCE AHEAD OF THESE
HEIGHT FALLS.  THE LATEST SUITE OF OPERATIONAL---HI RES AND SREF
GUIDANCE IS SHOWING INCREASING DIVERGENCE IN QPF DETAILS IN WHAT
IS EXPECTED TO BE AN ACTIVE PRECIPITATION PATTERN---LEADING TO LOW
CONFIDENCE IN THE SHORT TERM DETAILS.  HOWEVER---WITH A VERY
FAVORABLE PATTERN FOR MODERATE TO HEAVY PRECIPITATION AMOUNTS
AHEAD OF THE AFOREMENTIONED HEIGHT FALLS---CONFIDENCE IS GREATER
THAT THERE WILL BE WIDESPREAD MODERATE TO HEAVY PRECIPITATION
TOTALS ACROSS THESE AREAS.   AREAL AVERAGE .50-1"+ AMOUNTS
DEPICTED ACROSS THESE AREAS DAY 1---WITH THE DAY 1 QPF LEANING
MORE TOWARD THE BETTER PERFORMING IN HOUSE PSEUDO BIAS CORRECTED
ENSEMBLE MEAN. 

EASTERN MAINE

THE INCREASINGLY NEGATIVELY TILTED HEIGHT FALLS MOVING OFF THE
EASTERN NEW ENGLAND COAST EARLY THIS MORNING ARE EXPECTED TO
CONTINUE TO AMPLIFY INTO A CLOSED LOW MOVING TO THE SOUTH OF THE
CANADIAN MARITIMES THURSDAY.   THERE IS FAIRLY GOOD AGREEMENT THAT
THE BULK OF THE PRECIPITATION WITH THIS AMPLIFY SYSTEM WILL REMAIN
ACROSS NOVA SCOTIA INTO NEW BRUNSWICK--IN AN AXIS OF ENHANCED UVVS
ALONG AN INVERTED TROF EXTENDING NORTHWESTWARD FROM THE ASSOCIATED
DEEPENING SURFACE LOW---WITH THE WESTERN EDGE OF THE QPF AXIS
BRINGING POTENTIAL FOR MODERATE PRECIPITATION
AMOUNTS---.25-.50"---TO FAR EASTERN MAINE THIS PERIOD.

ORAVEC

GRAPHICS AVAILABLE ON THE WEB AT www.wpc.ncep.noaa.gov/qpf/qpf2.shtml

24HR QP VT 25/12Z
 0.01 466622 476625 486627 491628 496631 500634 503639 506645
      509652 513670 515676 515686 514693 512696 511700 510705
      507712 503715 496717 487714 478709 469702 459697 442684
      438681 432680 426682 421680 417677 412673 408670 405665
      403661 404653 405647 408641
 0.01 547036 547026 545020 542008 541002 542000 540994 537984
      535977 531962 527947 518923 514908 511895 506880 500866
      496861 493853 490847 487843 483839 479839 469844 458843
      449840 437835 427829 417823 407819 386813 375812 366809
      359806 355803 349800 343798 338797 330798 327802 327806
      325810 316814 309815 303814 292813 282810 277807 271805
      268806 266809 269815 272818 277821 287823 293825 299827
      304830 309832 316831 320828 324824 326819 330813 332814
      334816 341827 341835 339841 335853 332865 328876 324889
      320898 317913 317917 315921 312926 308930 305937 302942
      301949 301956 303962 306964 310962 315961 317967 324974
      332975 340975 355976 360978 368979 375979 380977 390972
      394969 398967 408962 421963 431970 435974 441978 450983
      460984 473985 481985 489987 493989 497993 500998 503001
      511014 514020 517027 521038 524050 525055 527056 532060
      534062 537062 541057 543054 545052 545047 546038 547036
 0.01 533208 534202 535195 534184 528164 524155 519149 507140
      501143 498142 495139 489133 480128 474125 471123 471117
      474110 473105 470102 455100 453098 448096 444097 439097
      434096 431094 428095 430100 429107 428109 429115 437117
      440119 442123 443128 439129 432134 424136 418140 408149
      402155 401159 404160 409162 411167 410174 408179 407185
      409187 410190 411196 409202 408206 403205 400202 392198
      386194 382191 377190 374189 373194 376202 381209 394218
      395221 394224 385223 382225 379229 378233 381236 386242
      393246 394249 399251 409256 416259 420260 423259 439254
      442253 448254 451253 455254 464257 471257 473260 477263
      483268 489273 496281 501286 507286 512279 514275 516267
      520260 524254 521244 517234 513225 509217 510210 513209
      519213 523216 527215 533208
 0.01 468207 469203 467200 463199 461201 458201 456202 454206
      452208 454211 457212 458210 460208 462208 466209 468207
 0.01 452210 452208 452205 453203 453201 451201 450202 449205
      449207 448207 447209 447211 446214 447214 449214 450212
      451211 452210
 0.25 453626 467634 474639 479644 491656 496663 500672 502678
      500684 494689 486691 481692 477690 463684 450674 444669
      439663 433655 430650 430644 438631
 0.25 512266 514261 515256 513249 512241 510233 505223 498211
      493207 490206 479208 474212 470216 465214 459215 449217
      436216 432214 429212 427213 424218 421221 418220 416216
      410214 404211 398207 396205 393203 389203 388205 390210
      394214 403220 409223 410226 410229 400234 397238 400243
      411248 417249 424248 429247 434244 442237 449230 454227
      462229 466226 470221 474221 479223 485226 490229 492236
      496242 499244 499250 495248 489237 486236 484237 481234
      479231 475231 471230 469233 466234 464236 464241 467245
      471249 480255 490265 496274 501279 505281 507279 509277
      510271 512266
 0.25 517188 517181 513176 506168 495163 487156 484154 481154
      476155 471151 468147 465144 462142 458142 455146 450148
      445145 441141 436141 433146 431151 430158 429165 430171
      441175 442182 442186 444187 449190 454190 458188 462184
      469175 474176 478178 482181 489184 493184 498182 503182
      508186 514188 517188
 0.25 516965 516953 514945 509925 505905 503896 501891 494878
      487861 483857 478853 471852 463853 456854 450857 445861
      437864 430867 427867 426862 424855 420848 415849 410854
      401866 395869 390867 386863 382858 376855 371853 361853
      359851 359844 358835 355829 352828 349829 346838 343851
      339868 336875 336882 338891 337897 331909 331913 331919
      336924 346924 348925 350928 353934 353940 354943 358948
      366949 381952 390952 396950 407943 411940 417938 423954
      428957 437959 449961 464962 480964 487965 493967 499971
      505974 510974 513971 516965
 0.50 510257 511250 510244 507235 503225 498217 495214 491212
      482214 481218 484221 491227 494236 500243 504252 506258
      508259 510257
 0.50 505276 503265 497255 492245 489241 485243 481242 480236
      478234 475233 472236 472242 476246 481249 484253 490262
      497271 505276 505276
 0.50 507957 508952 507949 504943 502935 501924 499908 498899
      496891 490880 483867 480863 475861 469860 462861 457863
      452865 447869 442873 433883 429885 425885 422884 402873
      391878 385877 380873 373865 372864 367863 360862 356866
      352870 348874 345879 342891 337906 337910 343912 347912
      349913 355916 356923 358928 366940 376945 383947 389946
      395944 399941 409933 414930 421929 431933 435939 438942
      450940 454939 457932 464923 469927 472931 479942 487952
      491956 496958 503961 507957
 0.50 483664 482659 479654 473647 467642 460639 452638 448640
      446643 446647 447651 449655 453663 459671 466675 474675
      479673 481670 483664
 0.50 489175 489170 488168 486166 483163 481163 480163 476164
      476165 477167 479170 482173 483174 487176 489175
 0.50 463223 462219 457219 454218 450219 443219 436220 429220
      425223 431228 434230 437229 442227 447226 450225 454221
      457221 460224 463223
 0.50 457182 459179 458177 456174 456168 457162 455158 451156
      446152 441147 436148 434154 435160 440166 444170 449175
      454181 457182
 0.50 428243 429239 428236 423235 418233 413233 410235 405235
      403235 402237 404242 408244 413245 416245 420245 425244
      428243
 0.50 402216 403214 402213 400213 399211 398210 397208 396208
      396206 394207 394209 395211 395212 396213 398214 399215
      400215 401216 402216
 0.50 353844 353839 351838 350839 347844 345851 344856 342863
      341871 341876 345871 347866 349862 351855 352846 353844
 1.00 501238 501235 500234 499232 498231 497229 496231 496233
      496234 498235 499237 501238 501238
 1.00 495259 494258 494256 493255 493253 492252 491250 490250
      489252 490254 491255 491256 492258 493259 494261 495259
 1.00 453896 453889 451887 448888 442894 439897 435901 427905
      419910 408912 398915 390918 373926 371929 373935 376937
      382938 387937 392934 400929 409926 417921 425917 433913
      436911 438911 439915 443918 447920 450921 452916 453909
      452901 453896
 1.00 419240 420238 419237 418236 417237 417239 419240 419240
 1.00 410898 408898 406898 404899 406901 408901 410899 410898
 1.00 377893 377889 376884 370883 365882 361881 358881 352881
      349886 348892 348897 349900 353904 359903 364901 371898
      375896 377893
 1.50 358899 358896 358895 356896 356897 357899 358899 358899