000
FXUS04 KWBC 181747
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
146 PM EDT SAT MAY 18 2013


PRELIM DAY 1 QPF DISCUSSION
VALID MAY 19/0000 UTC THRU MAY 20/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


...WEST...

VERY UNSETTLED WEATHER CONTINUES FOR THE WRN STATES AS PAC SHRTWV
ENERGY CONTINUES TO DIG INTO THE BACKSIDE OF THE BROAD UPPER TROF
ADVANCING SLOWLY EWD FM THE INTERIOR WEST.  AMPLE MOISTURE..
DIURNAL HEATING AND BROAD SCALE VERTICAL LIFT SHOULD RESULT IN
WIDESPREAD QPF ACROSS THE INTER-MOUNTAIN WEST..ESPECIALLY ALONG OR
JUST EAST OF THE FRONT RANGE OF THE NRN ROCKIES.  MODEL QPFS HAVE
BROAD GNRL AGREEMENT BUT SPECIFICS ARE ANOTHER MATTER.  THE GEM
REGIONAL AND ECMWF APPEAR TO HAVE BETTER AGREEMENT ON DETAILS THAN
MOST OTHER GUIDANCE AND LEANED TWDS A BLEND OF THOSE MODELS FOR
THE FCST.

...PLAINS/UPPER MIDWEST...

THIS IS A QPFERS NIGHTMARE.  THERE ARE SGFNT MODEL QPF DIFFERENCES
NOT ONLY BTWN ONE ANOTHER..BUT ALSO THE SAME MODEL FROM RUN TO RUN
AS THE ATMOSPHERE IMPOSES SUMMER LIKE MSTR WITH SPRING LIKE
DYNAMICS.  BEST THING TO SAY AT THIS POINT IS THAT THE UKMET..AT
LEAST IN REGARDS TO ITS QPF..HAS SHOWED BETTER RUN TO RUN
CONSISTENCY THAN THE OTHER GUIDANCE..PARTICULARLY OVR THE NRN
PLAINS AND UPPER MS VLY.  ITS QPF ALSO HAS SUPPORT FM THE GEM
REGIONAL EARLY IN THE PD AND THEN TO SOME EXTENT THE 18/00Z ECMWF
DURING THE 2ND HALF.  FOR THAT REASON LEANED TWDS ITS GUIDANCE FOR
THE MANUAL QPF.  IN ANY CASE..THERE IS LITTLE DOUBT THAT HGT
FALLS..AND STG JET FORCING ASOCTD WITH THE ADVANCING WRN U.S. TROF
WILL PRODUCE SGFNT RNFL TOTALS GIVEN THE LIFT THAT WILL BE
GENERATED ON BOTH THE SYNOPTIC AND EVENTUALLY TO SOME EXTENT THE
MESOSCALE.  ABOVE TO MUCH ABOVE NORMAL PER PWS ARE ALREADY IN
PLACE TO SUPPORT THE EVENT WITH A CONTG NWD MSTR FLUX THRU THE
CNTRL U.S. CONTG TO REPLACE MSTR.  ONE BIG FLY IN THE OINTMENT IS
TO WHAT EXTENT THE CAP CAN BE BROKEN OVR THE SRN AND CNTRL PLAINS
HENCE GENERATING SHWRS THAT COULD INHIBIT THE NWD MSTR FLUX AS
EXPECTED.

...SERN U.S./MID ATLC STATES AND ADJACENT APLCNS...

A WEAK MID/UPPER LVL LO/TROF WILL CONTINUE TO ADVANCE SLOWLY EWD
THRU THE FCST PD AND GENERATE SCTD AREAS OF SHWRS..SOME VRY
HVY..ACROSS THIS RATHER LARGE AREA OF THE NATION.  MODEL QPFS ARE
BEGINNING TO REFLECT THE WKNG UPPER SYSTEM AND ARE NOW SHOWING
LARGER DIFFERENCES AND RUN TO RUN DISCONTINUITIES.  FOR THE QPF
TOOK A BLEND OF THE GEM REGIONAL AND UKMET WHICH HAVE BEEN DOING A
RELATIVELY GOOD JOB TO THIS POINT IN TIME HANDLING THIS SYSTEM.
STILL SOMEWHAT CONCERNED ABOUT THE POTENTIAL FOR HVY RAINS TNGT
OVR NRN AL/W CNTRL GA WHERE ISENTROPIC LIFT WILL CONTINUE ON THE
BACKSIDE OF THE MID/UPR LVL COOL POCKET.

KORTY

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

24HR QP VT 20/00Z
 0.01 535195 536184 536176 534153 534146 532143 528134 524127
      519121 505100 499087 495080 493074 489061 489050 489040
      496013 499999 501995 503986 510961 512954 513943 515924
      515911 516906 516899 516877 515868 515857 516849 514838
      512822 510816 508813 505814 502817 498822 495828 493835
      490841 485839 478833 474831 470828 469829 467832 464839
      464844 466852 468861 471864 473874 472878 469881 460892
      447899 442900 433901 428899 422898 415899 411898 405900
      403903 405912 402913 400912 388897 383889 380887 380882
      379875 378868 376859 377853 381849 387846 393845 398845
      404842 405837 406832 407829 409821 410819 409814 408809
      409804 407799 406792 409779 412767 414760 414754 418741
      415735 411733 407732 403732 388728 383727 378727 373726
      368728 347733 341741 340748 344753 348758 351762 350766
      348771 342777 326793 315801 311804 305807 300808 297808
      288805 279803 270802 260803 257806 255811 253814 256816
      263820 271824 277825 282828 307829 309833 310838 308849
      307855 311863 317866 322862 325862 327864 333875 342895
      346898 350898 352896 355893 358893 361894 365897 372902
      381910 385914 388916 387921 365937 360941 358945 350956
      347959 340961 333963 330965 313976 306981 298988 288002
      288006 293007 305005 311004 316000 320998 328996 332995
      337996 342998 358996 359999 358001 356005 355009 357011
      362014 363016 363020 363025 363033 365039 366044 370049
      375054 379055 381056 382058 379062 368063 365064 366068
      367072 370082 372086 376091 381092 385094 386095 388094
      392090 396092 401088 405083 408082 411083 411088 408091
      407095 404099 387111 380119 376122 376130 381139 385141
      388145 395151 398160 399167 402171 412180 413185 411189
      406202 423214 421226 425228 427231 426236 424238 424242
      425243 430244 436242 442242 448244 453243 459244 465242
      469239 474240 477241 479240 478232 479228 481227 484226
      487226 490227 494231 496236 500237 502231 506227 510223
      511222 510218 509212 507208 510204 516205 519206 522210
      526213 528213 531209 532202 535195
 0.01 484205 486199 485193 482187 480179 477177 473173 469174
      465178 459186 455194 449193 446197 445202 442203 439202
      437199 434197 430200 428199 427202 429207 434212 440213
      448214 455215 460212 464210 470210 473208 477208 484205
 0.01 484152 484147 483145 480145 477143 474143 471145 474149
      474150 476152 479153 482154 484152
 0.01 443178 445175 443171 443170 440165 437163 435160 433156
      431148 430144 427140 423141 421146 422153 423158 425161
      425164 422166 420174 424181 429183 432187 434188 438189
      441181 443178
 0.01 419142 419138 418134 416132 414131 411131 408131 407133
      406137 407138 410141 413143 416142 417142 419142 419142
 0.25 509900 509892 508883 506874 503867 501865 497864 492867
      489870 484877 479884 471895 456909 451915 447917 441918
      428916 426917 425922 423924 419924 388943 382947 378952
      375960 375964 377969 380972 387978 393982 388988 383994
      381999 387001 394001 397004 399007 399013 398018 396026
      396033 398038 409043 424048 430052 433057 434062 436071
      439081 437101 438111 441117 443121 448124 456121 464118
      467119 470121 478124 483128 494140 502142 506142 507134
      504126 501117 494099 488083 483074 479063 476053 475041
      476031 478021 480011 482002 490982 496963 501945 506928
      507918 508910 509900
 0.25 401750 400743 396740 388738 375738 372738 367742 363748
      360756 359763 356773 354776 350780 345785 337790 330796
      325804 317815 323823 318831 316837 315843 315850 320851
      322851 326852 336863 342872 346878 350880 355878 361872
      358865 356845 362839 370834 377830 384824 391817 395809
      394799 392794 392789 401754 401750
 0.25 412118 413114 412113 410110 409106 406105 406106 405110
      403112 400113 397113 400117 403118 406118 408119 411118
      412118
 0.25 395117 394115 391116 391117 394117 395117
 0.25 396083 396079 395079 395083 395084 396083
 0.25 300818 298816 294814 289812 285811 282810 279810 273811
      273816 276818 280819 285821 288821 292821 297820 300818
 0.50 504906 503896 502885 499877 496875 491878 488881 482889
      476899 468907 454920 446928 436935 429950 420958 417962
      415967 413971 412977 413984 411988 407000 405011 403022
      402027 403032 414037 423039 431041 435044 438048 441052
      444058 443067 447071 449073 451072 452069 450064 448060
      447056 451054 455049 461041 465031 463027 458028 455029
      454026 455022 457020 464013 474997 485976 489965 491955
      496942 500929 502919 504906
 0.50 490121 489103 487095 484090 476078 472073 468070 460071
      456073 456080 457089 456093 454094 450094 447097 448103
      447107 444113 447115 449112 454109 457108 460107 465110
      476115 487122 490121
 0.50 391752 388749 385747 378745 375745 371748 368753 362770
      360775 356781 350786 342791 336795 331799 327806 326810
      329815 330823 326828 320833 318840 319844 322845 328848
      338856 342861 346867 347870 352869 351860 350854 348848
      347845 348840 354835 360832 366827 370820 373813 377808
      382804 381792 381789 384786 387780 388774 388765 389759
      391752
 0.50 401955 402951 399949 396948 394950 391953 388955 388957
      389958 392958 394957 397957 400956 401955
 1.00 495914 495907 494899 494893 491889 487895 484902 479909
      474913 463923 453933 448945 441959 437963 430965 424970
      421973 420978 420984 418991 413008 410022 415027 423029
      438024 442026 446023 449015 455006 460000 465993 473982
      476976 480967 484953 489938 493923 495914
 1.00 359796 356792 353791 348793 342796 339798 335802 333804
      335807 340807 343807 347809 347812 350815 354814 359812
      360807 358803 358800 359796
 1.00 332840 333836 330835 328835 327835 326836 326839 328840
      331841 332841 332840
 1.50 481936 481930 480926 473929 471932 465935 461934 457936
      454941 452947 452952 460947 463943 465944 466948 463954
      458959 455960 452952 450957 446964 443970 441974 437978
      430979 426982 425989 422994 420000 419008 419010 425011
      430008 433005 436006 442005 445003 448003 452998 456996
      460992 462988 469974 473964 477951 480938 481936
 2.00 464975 465970 463968 460967 457970 454972 452975 450977
      449980 448982 450984 450986 453989 456990 457989 459986
      460984 461981 462979 464975 464975

$$