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Quantitative Precipitation Forecast
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000
FXUS04 KWBC 211902
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
302 PM EDT TUE MAY 21 2013


PRELIM DAY 1 QPF DISCUSSION
VALID MAY 22/0000 UTC THRU MAY 23/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR



DAY 1

PACIFIC NORTHWEST INTO THE NORTHERN GREAT BASIN AND NORTHERN
ROCKIES

NO MAJOR MODEL DIFFERENCES WITH THE STRONG HEIGHT FALLS DIVING
SOUTHEAST ALONG THE SOUTHWEST CANADIAN/PACIFIC NORTHWEST COAST AS
THEY SWING SOUTHEASTWARD AND INLAND INTO THE PACIFIC NORTHWEST.
PERSISTENT ONSHORE WESTERLY LOW LEVEL FLOW ON THE SOUTHERN SIDE OF
THIS CLOSED LOW WILL SUPPORT MODERATE TO ISOLATED HEAVY
PRECIPITATION TOTALS FROM THE WA/OR CASCADES---WESTWARD TO THE
WA/OR COAST RANGE AND OLYMPIC RANGE.  FARTHER INLAND THE
COMBINATION OF UPSLOPE FLOW FROM BOTH THE WEST SOUTHWEST AND THE
SOUTHEAST WILL SUPPORT MODERATE TO HEAVY PRECIPITATION POTENTIAL
FROM NORTHERN ID--FAR NORTHEASTERN WA AND NORTHWESTERN MT.
OVERALL---MODELS ARE IN GOOD AGREEMENT WITH THIS PRECIPITATION
DISTRIBUTION---WITH THE NAM AND SREF MEAN USED FOR QPF DETAILS
THIS PERIOD.


EASTERN TX/LOWER MS VALLEY---NORTHEASTWARD INTO THE OH VALLEY AND
LOWER GREAT LAKES

STRONG HEIGHT FALLS ROTATING EASTWARD ACROSS THE SOUTHERN PLAINS
ARE SIGNALING A MORE PROGRESSIVE NATURE TO THE ACTIVE CONVECTION
THAT HAS BEEN ACROSS PORTIONS OF THE SOUTHERN PLAINS INTO THE
LOWER MS VALLEY.  CURRENT SLOW MOVING CONVECTION MOVING WEST TO
EAST ALONG AND NORTH OF THE OUTFLOW BOUNDARY STRETCHING FROM
NORTHEAST TX INTO SOUTHERN AR WILL BE PUSHED SOUTHEASTWARD BY THE
MORE PROGRESSIVE CONVECTION THAT HAS FORMED AHEAD OF THE STRONG
HEIGHT FALLS AND ASSOCIATED COLD FRONT MOVING EASTWARD THROUGH THE
SOUTHERN PLAINS.  THIS CONVECTION SHOULD REMAIN WELL DEFINED THIS
EVENING INTO THE OVERNIGHT HOURS IN AN AXIS OF ABOVE AVERAGE PW
VALUES AND FAVORABLE UPPER JET DYNAMICS PUSHING INTO THE LOWER MS
VALLEY. THERE IS A GENERAL MODEL AGREEMENT ON A DECREASE IN HEAVY
RAINFALL POTENTIAL BY EARLY WEDNESDAY AS UPPER DYNAMICS WEAKEN.
HOWEVER---WITH PW VALUES REMAINING ABOVE AVERAGE FROM THE LOWER MS
VALLEY NORTHEASTWARD THROUGH THE OH VALLEY AND INTO THE LOWER
GREAT LAKES---ORGANIZED PRECIPITATION LIKELY ACROSS THESE
AREAS--ALBEIT WITH A LESSENED HEAVY RAINFALL THREAT.

UPPER MS VALLEY INTO THE GREAT LAKES

THERE IS GOOD MODEL AGREEMENT ON A SLOW EASTWARD MOVEMENT TO THE
WELL DEFINED CLOSED LOW MOVING INTO THE UPPER MS VALLEY REGION DAY
1.  ADDITIONAL LONG DURATION LIGHT TO MODERATE PRECIPITATION
AMOUNTS LIKELY IN THE COMMA HEAD/DEFORMATION PRECIPITATION BAND
ASSOCIATED WITH THIS UPPER CENTER.

UPPER LAKES--NORTHERN NY INTO NORTHERN NEW ENGLAND

TO THE EAST OF THE UPPER MS VALLEY CLOSED LOW---WEST SOUTHWESTERLY
TO SOUTHWESTERLY LOW LEVEL FLOW WILL CONTINUE TO OVERRUN THE WEST
TO EAST ORIENTED WARM FRONTAL BOUNDARY MOVING SLOWLY NORTHWARD
THROUGH THE UPPER LAKES---NORTHERN NY AND NORTHERN NEW ENGLAND.
THIS WILL CONTINUE TO SUPPORT MODERATE TO HEAVY RAINFALL POTENTIAL
AMOUNTS IN THE OVERRUNNING ZONE TO THE NORTH OF THIS BOUNDARY.
CONFIDENCE IS LOW WITH QPF DETAILS GIVEN THE WIDE SPREAD IN MODEL
QPF SOLUTIONS.  DAY 1 QPF USED A COMBINATION OF THE SREF MEAN AND
ECMWF FOR QPF DETAILS---DEPICTING AREAL AVERAGE .25-.50"+ AMOUNTS
WITH LOCALLY HEAVIER TOTALS POSSIBLE.

FL

THE CLOSED LOW OVER NORTH FL IS EXPECTED TO MOVE ONLY VERY SLOWLY
EASTWARD THIS PERIOD.  PERSISTENT SOUTHERLY TO SOUTHEASTERLY LOW
LEVEL FLOW TO THE SOUTH AND SOUTHEAST OF THIS UPPER CENTER IN THE
AXIS OF ABOVE AVERAGE PW VALUES STREAMING OFF THE ATLANTIC WILL
MAY FOCUS ISOLATED VERY HEAVY RAINFALL AMOUNTS ALONG THE COASTAL
SOUTHEAST PORTIONS OF FL. THESE HEAVY TOTALS MORE LIKELY IN THE
EARLY MORNING HOURS--WITH CONVECTION THEN PROGRESSING INLAND
DURING THE AFTERNOON.   ISOLATED 2-5"+ TOTALS POSSIBLE ALONG THE
COASTAL SOUTHEAST---ESPECIALLY IN THE EARLY MORNING HOURS---WITH
VERY LOW CONFIDENCE WITH PLACEMENT. THESE INTENSE RAINFALL RATES
AND AMOUNTS POSE RUNOFF ISSUES---ESPECIALLY OVER URBANIZED AREAS
ALONG THE SOUTHEAST COAST OF FL.



ORAVEC

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

24HR QP VT 23/00Z
 0.01 490671 487669 484664 479654 476653 475650 472643 465640
      455637 446654 431663 427667 421676 421682 420690 421694
      420697 418699 413704 413715 413721 411726 410730 408733
      405743 401759 400767 398772 394774 386778 382782 367784
      355779 351777 350772 349771 346772 332765 325764 316769
      300776 293778 288776 281773 275771 269775 268778 264780
      260783 257782 253784 246792 241797 237805 234811 233814
      235820 239825 244828 248832 254835 265841 270842 277842
      280842 283837 286835 289836 298836 305835 311839 317842
      321844 325845 328847 331851 331855 330858 319867 312871
      310874 306876 301881 296886 280905 277911 274914 272917
      273924 275928 276934 277944 275952 273964 275979 274992
      276998 281001 288000 292996 316976 326968 331962 336957
      340954 343948 352938 358934 364933 368934 373934 380935
      396926 399924 401925 402929 403935 405937 414949 418956
      423961 425963 427970 428982 431989 433000 440016 443020
      446027 449031 454031 464030 470025 475016 475010 477004
      477995 479989 479986 479980 480973 495896 499875 498865
      499860 498853 498845 498841 498834 500824 501804 503795
      502788 503782 501772 502768 502763 501757 501753 499740
      499735 498729 495718 495712 493703 491691 490680 490671
 0.01 534225 536209 536196 536189 536181 534175 521144 514136
      507130 497121 489119 482116 477112 476106 474102 468098
      459093 453090 447088 445087 441088 435091 430087 426087
      424088 427094 430098 429102 423103 423107 425110 431115
      435116 437114 441115 446121 446125 448130 449134 449142
      447144 443144 439140 439137 435148 435157 439165 443172
      443179 441182 438192 438197 440201 459203 459206 457208
      454210 450213 447212 430210 426209 424213 421221 421226
      417230 410231 404231 400230 401241 401251 403253 407254
      415257 419259 423262 451267 464274 480281 489286 499292
      503294 507292 512287 516280 518273 525252 530235 534225
 0.25 475694 473685 469676 461670 454666 445670 441673 440676
      437686 437697 431708 428711 425718 423730 422737 420741
      417750 413760 410769 409779 408783 409791 411794 411798
      411804 409810 406816 392828 388832 383835 374841 367845
      361851 329876 315887 302898 297902 294906 290914 287924
      287933 287943 286952 284960 284965 287968 289971 290979
      291981 294981 298979 305975 312970 325960 338946 344939
      350930 356924 363919 369914 371909 375906 386904 391902
      395899 403891 408887 409881 411877 415877 415888 417892
      423893 428892 431894 433900 436903 439905 444906 449903
      454892 457887 458885 461885 464889 466888 469885 470880
      471876 471868 469838 467807 466799 467795 468789 469784
      475763 478751 478739 476724 476713 475694
 0.25 528208 529203 529197 528189 524177 520164 517153 512147
      507142 498137 490131 487129 481126 474126 471127 469131
      466135 463137 460140 457146 456151 452158 452162 454171
      457174 460172 465172 471174 477181 481188 483195 482200
      481204 477206 470210 461212 456215 449216 440216 432218
      428220 425222 427226 429231 427235 422237 419240 418243
      419247 422250 427253 434254 445256 454256 461255 465253
      473251 480255 484260 489270 495278 499283 503287 507284
      511275 514271 516264 517262 516254 514239 514234 516228
      520220 523217 525214 528208
 0.25 499246 498245 496243 495240 494236 493235 492230 491230
      489226 486224 483223 480225 479226 480228 480230 482235
      482236 484240 487241 490242 493243 494244 495246 498248
      499246
 0.25 466940 465934 459934 455934 453935 449940 446945 443950
      442954 445961 448963 453961 456958 460954 464950 466944
      466940
 0.25 308801 305796 303795 297792 287790 274789 268788 260789
      255791 250794 246799 244805 245812 245814 249815 259812
      265810 270811 284811 297812 304807 308801
 0.50 512261 512256 510250 507249 507250 508254 508257 509260
      511262 512261
 0.50 519206 521202 522197 521190 518181 513170 511165 508160
      508157 505157 502155 503153 508155 509151 505147 497142
      491135 488134 485134 486139 489143 492148 491151 473153
      466156 466162 469164 473167 476171 480177 486187 490196
      496203 498207 503210 508211 515209 519206
 0.50 464698 461690 457688 454684 451682 450689 451694 452698
      451702 451708 448719 443723 436723 433724 430728 428733
      426744 422754 419765 419769 420773 422774 428771 431771
      439774 448777 451777 454776 455774 460764 467757 469750
      469743 469732 469723 468717 467709 464702 464698
 0.50 506277 505275 504272 503269 503266 501264 498263 496264
      495268 497271 498274 499276 502279 504280 506277
 0.50 458825 457822 456821 453820 452824 451826 451829 452833
      453837 454840 455842 458841 458839 458834 458830 458829
      458825
 0.50 467239 467234 463230 465221 463216 455216 450217 446217
      440218 437219 430224 434233 431239 429240 429244 432247
      443250 452250 458249 462246 465243 467239
 0.50 445832 445826 443820 441815 439811 435809 430809 426811
      420817 412826 403835 393842 374857 361865 349872 327883
      319892 313901 304907 296914 293919 292925 292938 289961
      294963 293970 292974 295975 301973 318963 328955 336947
      343938 348930 356918 363910 370901 373897 379893 388883
      390878 390874 388869 392866 397861 404858 408857 412857
      418859 423861 426867 425873 426878 429875 431871 432867
      445832
 0.50 293804 290799 287796 280793 273792 264791 256794 250799
      250803 252806 260805 269805 278807 284808 290807 293804
 1.00 504187 504178 503173 500168 496164 493162 487161 484160
      483165 484166 486172 489177 491182 494186 499190 504187
 1.00 459241 459237 458236 455235 454235 452236 449236 446236
      445236 443238 440239 442241 445242 448243 451243 452243
      454242 457242 459241
 1.00 452222 451221 448220 445219 443219 442219 439222 438222
      439223 441226 444227 447227 449225 451223 452222
 1.00 366897 365893 362892 356893 349891 342892 336894 327898
      312911 303918 300921 298925 299932 301936 302943 306942
      310941 310945 306955 305961 309963 317959 327953 333947
      345930 351921 356913 363905 366897
 1.00 283802 281799 277798 272796 268796 265795 260797 255800
      255801 259802 264801 268801 273802 276803 280804 283805
      283802
 1.50 363897 362894 359894 353896 346898 339899 332901 327904
      322908 320913 316923 317928 318932 324929 328928 333930
      337932 342931 345927 349923 354914 360905 363901 363897
 2.00 360898 359898 356898 354900 353900 351902 349904 348905
      346908 345910 344912 342914 341914 342914 345914 347913
      350912 351912 353911 355908 356907 357904 359902 360902
      360898

$$
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