Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 160725
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
324 AM EDT MON OCT 16 2017


PRELIM DAY 1 QPF DISCUSSION
VALID OCT 16/1200 UTC THRU OCT 17/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...PACIFIC NORTHWEST...

A STRONG JET STEAK OVER THE NORTHERN PACIFIC WILL HELP CARVE OUT A
SHORTWAVE THAT WILL MOVE QUICKLY TOWARD THE PAC NW TUE MORNING.
INCREASING UPPER DIFFLUENCE AND ATTENDANT DEEP LAYER WARM/MOISTURE
ADVECTION AHEAD OF THE TROUGH WILL MAKE FOR A PROGRESSIVELY WET
PATTERN ACROSS THE NORTHERN WA COASTAL AND CASCADE
RANGES...ESPECIALLY LATER IN THE PERIOD (00-12Z TUE) WHEN AN
ATMOSPHERIC RIVER OF 1-1.25" PWs AND STRONG WESTERLY LOW LEVEL
MOISTURE TRANSPORT DROPS SOUTH OF VANCOUVER ISLAND. 850-700 MB
MOISTURE FLUX ANOMALIES DURING THIS TIME ARE EXPECTED TO CLIMB TO
NEAR 3 STANDARD DEVIATIONS ABOVE NORMAL PER THE SREF AND GEFS...TO
GO ALONG WITH THE PW ANOMALIES AROUND +2. THIS ALONG WITH THE
PREDOMINATELY WESTERLY (LARGELY ORTHOGONAL) LOW-LEVEL FLOW WILL
LEAD TO 12 HOUR LIQUID EQUIVALENT ACCUMULATIONS AVERAGING BETWEEN
1-1.5" ACROSS THE OLYMPIC AND NORTHERN CASCADE RANGES IN NORTHWEST
WA.


...MID ATLANTIC TO SOUTHEAST...

AN UPPER LEVEL TROUGH ACROSS THE OH/TN VALLEYS EARLY THIS MORNING
WILL TRANSLATE EASTWARD TO ALONG THE MID ATLANTIC-SOUTHEAST COAST
BY 12Z TUE. STRONG...ELONGATED DEEP-LAYER WESTERLY FLOW IN ITS
WAKE WILL FOSTER SUCH SWIFT EASTWARD PROGRESSION OF THE UPPER
TROUGH AND ASSOCIATED SURFACE COLD FRONT...PARTICULARLY FARTHER
NORTH (MID ATLANTIC)... THOUGH WITH THE WEAKER WESTERLIES THE
UPPER TROUGH WILL RETARD SOMEWHAT OVER THE EASTERN GULF COAST
WHILE THE SURFACE BOUNDARY BECOMES NEARLY STATIONARY ACROSS SOUTH
FLORIDA BY 12Z TUE. NEVERTHELESS...MODEST AT BEST UPPER LEVEL
FORCING AND WEAKENING 850-700 MB MOISTURE TRANSPORT/FLUX WITH
TIME...ALONG WITH THE LIMITED DEEP-LAYER INSTABILITY
OVERNIGHT...WILL INHIBIT THE HEAVY RAINFALL THREAT (CONVECTIVE
TRAINING POTENTIAL) ACROSS MUCH OF THE FL PENINSULA DESPITE THE
SLOWER SURFACE FRONTAL PROGRESSION.

HOWEVER...AN INCREASED CHANCE FOR CELL TRAINING AND THUS HEAVY
RAINFALL WILL BE POSSIBLE THROUGH THIS EVENING ALONG THE SOUTHEAST
COAST...CAPITALIZING ON THE LINGERING DIURNAL INSTABILITY (MUCAPES
1000-1500 J/KG). UTILIZING A MULTI-MODEL BLEND WITH THE QPF...WITH
THE BULK OF THE WEIGHT COMPRISING THE HIGH-RES CAMS (ESPECIALLY
THE NBM AND HREF MEAN)...MAXIMUM AREAL-AVERAGE RAINFALL AMOUNTS
ARE EXPECTED TO RANGE BETWEEN 0.50-1.25" ALONG THE SOUTHEAST COAST
FROM NORTHEAST FL TO SOUTHERN SC. SPOTTY 2-3+" TOTALS ARE LIKELY
HOWEVER PER THE VARIOUS HIGH-RES WRFs. GIVEN THAT THESE AMOUNTS
COULD FALL WITHIN A 3 HOUR PERIOD...ALONG WITH THE CURRENT SOIL
MOISTURE ANALYSIS FROM THE NATIONAL WATER MODEL...THE CURRENT 1-3
HOURLY FFG...AND THE LATEST SSEO 40KM NEIGHBORHOOD PROBABILITIES
OF QPF>FFG EXCEEDANCE LATER THIS AFTERNOON (TOWARD 00Z)...WE WILL
INCLUDE A NARROW "MARGINAL" RISK AREA IN THE DAY 1 EXCESSIVE
RAINFALL OUTLOOK (ERO).

HURLEY


GRAPHICS AVAILABLE ON THE WEB AT
WWW.WPC.NCEP.NOAA.GOV/QPF/QPF2.SHTML


24HR QP VT 17/12Z
 0.01 555873 555858 554848 551839 546830 542824 542814 541801
      539788 536778 532771 528766 522760 516758 512759 510758
      496765 492766 489770 485775 482782 479792 480799 481803
      482809 484812 487821 490830 495851 497862 499871 503880
      508885 513884 515883 517884 521887 524896 525905 528913
      534918 539918 541916 545909 549903 552892 554883 555873
 0.01 538216 540198 538187 537180 536176 533171 529167 522160
      517155 509151 506153 505156 507157 509163 507163 500159
      495176 496179 500182 500188 503190 510204 514214 513216
      511213 505207 501203 495201 490200 486201 480203 476206
      472209 470212 465213 464214 467218 476222 475225 472228
      469232 466232 464231 463234 463240 463251 463256 462260
      460265 459277 461290 462295 461301 460307 461312 465316
      471318 478314 484309 489304 496296 508301
 0.01 483839 482833 479829 472833 467824 461816 459812 461808
      462803 462797 461780 460773 456773 453776 451782 450792
      449797 446801 439808 436813 433813 431811 424808 417804
      408802 399799 393796 388797 385799 378805 372814 370817
      370820 385809 389806 395807 398808 402811 410814 418816
      434821 439824 442825 445823 444819 448819 451823 454827
      455833 459837 459835 459831 462834 464838 467843 469853
      474861 476863 478862 480857 482848 483839
 0.01 451718 450716 450714 449714 448714 446714 446715 447717
      448717 450719 451718
 0.01 458847 456845 454845 453845 452845 451847 451848 449850
      448853 448855 450855 451855 453855 455852 456850 458847
      458847
 0.01 449741 447738 444737 439745 435753 426755 421763 420766
      423771 425775 428779 432779 435776 438765 441757 447749
      448746 449741
 0.01 431790 431788 429786 428786 426786 424784 422787 423789
      424789 426791 428791 430791 431790 431790
 0.01 431862 431861 429861 428862 426862 424862 422860 420858
      419860 419863 421865 423867 424867 426867 428867 429864
      431862 431862
 0.01 230965 233971 238973 250973 257969 263962 278923 286903
      294887 297877 301870 304863 307859 313852 332841 338835
      342829 353813 360804 366796 372788 378780 383772 388765
      399746 407726 413704 413701 410697 407698 404701 392716
      389721 386725 382722 386717 388712 389706 386702 381701
      376703 372706 366705 357713 353716 348718 331729 322727
      315734 307750 298766 287784 280792 277795 275796 271796
      265797 259798 253802 249806 251813 255815 258817 261820
      266821 272822 273824 270825 263826 259824 252818 249816
      246817 239823 236833 236840 239844 244850 249853 254853
      260854 261857 261861 260873 260886 259895 259902 258908
      253917 249925 246929 243933 235939 232943 230950
 0.01 362825 361823 361821 360823 359823 358825 358828 356830
      355832 355835 355837 357835 357834 358832 359832 360830
      360827 362825 362825
 0.25 534225 536214 537202 536193 534184 527172 518162 514161
      515171 510169 506167 505171 504183 509187 514192 520207
      525219 528227 530230 532229 534225
 0.25 527251 521244 516234 514229 512225 505218 501213 499209
      496207 491207 486207 482208 479211 478213 478218 484224
      485228 482232 477231 473232 471237 471245 471252 471257
      470272 469286 469293 471299 474302 478302 484294 490286
      493285 497286 502290 507292 510290 513284 517281
 0.25 534840 534835 533830 532827 530825 528824 525824 521826
      520829 520832 520836 522839 524842 526843 527845 530844
      532843 534840
 0.25 383756 383752 380752 377757 374763 371768 369772 366779
      364784 365787 368786 372781 375776 377771 379766 382759
      383756
 0.25 359725 357723 354724 349729 344734 341736 337736 323736
      318742 314749 308761 300773 293785 290793 288799 287809
      289815 291823 294826 298827 306825 312821 314819 318818
      324818 327816 332810 333807 333803 330797 328794 325796
      313803 310802 310797 315792 321788 325783 328777 330774
      330768 330763 332759 336755 346744 353735 359725
 0.25 307844 306841 305843 301843 299840 297840 296843 295845
      295849 297851 299851 301849 303847 305846 307844
 0.25 284885 285881 283878 278879 276881 274878 272871 270867
      268870 265876 265880 268893 264903 261915 257925 251934
      245942 237948 234954 233959 234965 237969 242971 249970
      256963 261953 265942 268929 272919 273913 274906 283886
      284885
 0.25 279834 277832 273833 270833 267833 264833 260834 258834
      256836 257839 261839 264839 268839 271838 275837 278836
      279834
 0.50 533222 534213 535204 535197 533190 528180 522171 516163
      516168 518175 509172 509176 511182 515185 518189 520195
      522202 526212 531222 533222
 0.50 525257 520248 516238 513231 511227 503218 498210 495208
      492209 488209 483210 480213 480216 481218 486223 491231
      491237 487236 481236 478233 475233 473234 472239 475250
      477263 478276 478285 480287 485277 491277 495280 500285
      503286 507287 511283 519274
 0.50 331748 329744 326743 319748 315753 311759 305772 302778
      301783 299785 295790 292797 289805 291810 295809 300804
      303799 309785 319782 322771 325763 328756 331748
 0.50 325808 323802 318804 315807 313809 308811 302812 299815
      298819 301822 306820 310818 313815 317814 321812 324809
      325808
 0.50 270909 270906 270904 269904 269907 268908 267909 267911
      266912 266913 266915 264917 264919 263921 264922 265921
      266920 267919 267917 268916 268915 269913 269911 270910
      270909
 0.50 265927 263925 259927 255933 250941 245947 239952 237955
      236961 238965 241968 246968 250966 255960 259952 262943
      263933 265927
 1.00 521264 520256 519252 514240 510230 507226 503222 497213
      493212 489214 486215 486219 489223 493234 495240 498244
      501248 502254 498253 496249 493243 489239 485238 483243
      477235 475238 477242 482253 487262 493272 501279 507281
      510276 514275 516272 521264
 1.00 258945 257941 254941 251945 248949 246952 243954 242960
      242962 244963 248962 252958 254954 255950 257946 258945
 1.50 519263 517253 513243 510235 507231 503228 498221 495217
      492219 491222 492227 496238 501245 503249 504255 504260
      502259 496252 492244 489241 485240 485246 486251 489260
      494269 500276 503279 506277 508273 512273 517269 519263
 2.00 517265 517260 516256 513247 509238 503231 499225 496221
      494220 492224 493228 496237 500244 505252 506258 505263
      502262 500258 494251 490243 486243 486247 490257 493264
      497272 504276 506271 509271 513271 515270 517265
 3.00 514266 514261 513258 511249 507240 503234 499229 497225
      494225 496234 499240 504247 507254 509264 512268 514266
 3.00 501269 502266 501263 499260 498258 495254 494252 492250
      491247 488247 489250 490254 491258 492261 494263 495266
      497268 499270 501269
 4.00 507245 507243 506242 505242 504240 502241 503243 504244
      505245 506247 507245
 4.00 500266 499263 497260 496258 495255 493253 491250 490250
      490253 491256 493258 495262 497265 498266 500266
 4.00 502238 501237 500235 500234 498233 497234 498235 498237
      499238 501238 502238

$$





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