FXUS04 KWBC 010719 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 318 AM EDT SUN AUG 01 2004 PRELIM DAY 1 AND DAY 2 QPF DISCUSSION VALID AUG 02/1200 UTC THRU AUG 03/1200 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR PRELIM DAY 1... ...NEW ENG INTO THE MID ATLC STATES... WKNG/LIFTING OUT OF THE MID/UPR LVL TROF..A WKNG FNTL BNDRY..AND LESS FAVORABLE UPR JET DYNAMICS ALL PT TO LESS RNFL COVERAGE AND AMTS THIS PD COMPARED TO THE PAST COUPLE OF DAYS..WHEN THE SYS WAS MOVG THRU THE GTLKS AND OH AND TN VLYS. STILL..SLUG OF GTR THAN 2 INCH PWS UP THE NRN MID ATLC AND NEW ENG CSTS AND SOME RMNG WK LOW LVL CNVGNC LIKELY TO SUPPORT AT LEAST A BAND OF MSTLY MDT TO ISOLD HVY RNFL AMTS FM MD AND DE NNEWD INTO ERN ME. MDL QPFS WEREN'T THAT DIFF HERE..SO MANUAL QPF NOT THAT DIFF FM THEM ALSO. ...NC/SC... T.D. ONE PROGGED TO DRIFT NNWWD THIS PD TO VCNTY OF THE SRN NC CST BY MON MRNG. SYS RMNS RATHER DISORGANIZED EVEN NOW..AND ESP SO FM A RNFL PERSPECTIVE. THUS..NOT A LOT OF CONFIDENCE WITH QPF HERE. DECIDED TO GO CONSERVATIVE AND KEEP ANY MDT TO ISOLD HVIER RAINS ON THE INFLO SIDE OF THE SYS..UP THRU EXTRM NRN CSTL SC MUCH OF THE NC CST. ...GULF CST STATES... HI MSTR IN PLACE ALG THE GULF CST SHLD SUPPORT MAINLY DIURNAL CNVCTN..BUT WITH WK/NON EXISTENT MID/UPR FORCING AND LOLVL FOCUS HERE..TSTRMS WL LIKELY BE SCTTD IN NATURE. GFS QPF LOOKS TOO HVY HERE..WHILE THE ETA PROBABLY A BIT UNDERDONE..SO MANUAL QPF IS A COMPROMISE BTWN THE TWO. PWS IN EXCESS OF 2 INCHES AND A MODEST WSWLY H85 FLO INTO CNTRL AND SRN PTNS OF THE FL W CST SHLD AID IN MORE ORGANIZED CNVCTN THERE THIS AFTN..WITH SOME MDT TO LCLY HVY RNFL AMTS LIKELY FM TPA TO S OF FMY. ...NRN PLAINS/UPR MS VLY... WK S/WVS RIDING ALG THE SRN EDGE OF THE WLYS SHLD CONT TO TRIGGER CNVCTN PTNS OF THE NRN PLAINS INTO THE UPR MS VLY THIS PD..IN LOW LVL WAA REGIME. ONE SUCH S/WV NOW COMING INTO THE NRN PLAINS SHLD SPREAD CNVCTN INTO THE UPR MS VLY/WRN GTLKS ESP 1ST HALF OF THE PD..WHILE UPSTREAM SYS NOW OVR SWRN SASK/NRN MT SHLD INCREASE CNVCTN ACRS ND INTO MN LTR SUN AFTN/NGT..ON NOSE OF DVLPG 25-30KTS OF SWLY LLJ. GFS QPF IN ERN ND/WRN MN LIKELY A LTL TOO HVY..BUT DID BEEF UP THE ETA QPF..AND XPC MDT TO LCLY HVY RAINS ERN ND INTO WCNTRL MN. ...NAME... WHILE MID/UPR RIDGE GETS INTO A MORE FAVORABLE PSN TO SUPPORT MONSOON MSTR EVENTUALLY GETTING INTO THE SWRN U.S...THERE STILL IS A LOT OF DRY AIR CURRENTLY TO OVERCOME. THEREFORE.. CONDS WL REMAIN RELATIVELY DRY OVER THE NRN NAME AREA WITH ACTIVITY CONTINUING TO FOCUS PRIMARILY ALONG THE CNTRL/SRN PTNS OF THE SMO WHERE A MODEL BLEND WAS USED. DAY 2... THE DAY 2 FCST PERIOD SHOWS A GREAT DEAL OF UNCERTAINTY AND SPREAD LEADING TO A VERY LOW CONFIDENCE FORECAST FOR QPF ACROSS THE CONUS. THE UPCOMING FORECAST REVOLVES AROUND THE FUTURE OF TD ONE... A QUICK MOVING SHORT WAVE SLIDING ACROSS THE UPR MS VLY/GRT LAKES AND THE OLD UPPER-LEVEL LOW FROM NRN CA SHEARING OUT INTO THE INTER-MOUNTAIN REGION/NRN ROCKIES. THE ONLY CERTAINTY WITH THE 00Z MODEL GUIDANCE IS WITH THE CLOSED LOW SHEARING OUT INTO THE INTERIOR NW/NRN ROCKIES. THE GFS DOES APPEAR TO DEVELOP A FEW CONVECTIVE FEEDBACK VORTS BUT THE FLOW AHEAD OF THE DIGGING UPPER TROUGH OVER THE ERN PAC SHOULD BE VERY DIVERGENT ALOFT. MOISTURE STILL REMAINS AN ISSUE AS BOTH THE ETA AND GFS HAVE GENERALLY A .50 INCH TO .75 OF AN INCH PWS. BOTH MODELS HAVE BEEN UNDER-INITIALIZING/FCSTING PWS THROUGH THIS REGION THE LAST FEW WEEKS. ANYHOW... HPC FOLLOWED THE 00Z ETA CLOSELY WITH ITS MORE WIDESPREAD PRECIP HUGGING THE TERRAIN. AS THE UPPER RIDGE CENTER REMAINS STATIONARY OVER THE SRN PLAINS... MOISTURE SHOULD RETURN NORTHWARD THROUGH THE NAME AREA INTO THE SOUTHWEST. PWS WILL REMAIN VERY MOIST ACROSS THE SRN AREA OF THE TIER 1 REGION AND 1 INCH PWS WILL REMAIN PERSISTENT ACROSS SRN AZ/NM. FOLLOWING THE SHORT WAVE DETAILS DURING THE DAY 2 PERIOD IS RATHER DIFFICULT... EXPECT THE USUAL OF CONVECTION DEVELOPING OVER THE TERRAIN. THE VERY FAST MOVING SHORT WAVE BEGINNING OVER THE UPR MS VLY... SLIDING THROUGH THE GRT LAKES AND LIFTING INTO QUEBEC BY THE END OF THE PERIOD IS HANDLED DIFFERENTLY BY THE MODEL GUIDANCE. THIS IS DUE TO THE 00Z GFS DEVELOPING A CONVECTIVE FEEDBACK VORT AND GREATLY AFFECTING THE QPF AND INDUCING A SURFACE LOW WITH THE FEATURE. THE ETA/UKMET AND CANADIAN SEEM PRETTY CONSISTENT WITH EACH OTHER AND WERE FOLLOWED HERE. HPC FOLLOWED THE NHC/TPC OFFICIAL FCST WITH TD ONE ALONG THE SERN COAST DURING THE DAY 2 PERIOD. HOWEVER... EVERY 00Z MODEL OFFER A DIFFERENT SOLUTION ON THE FUTURE OF TD ONE. THE CANADIAN KEEPS THE 500 MB VORT AND SURFACE LOW WELL OFFSHORE THROUGHOUT THE FCST... THE ETA HAS TRENDED MUCH SLOWER WITH THE OVERALL TROPICAL FEATURE WITH A 60 HR POSITION JUST OFFSHORE OF ILM... THE UKMET DRIVES AN IMPRESSIVE 500 MB VORT/SURFACE LOW UP THE COAST INTO THE MID-ATL REGION AND GFS DRIFTS THE FEATURE FROM THE SC COAST TO THE ENE INTO THE ATLANTIC WITH THE SURFACE REFLECTION HUGGING THE COAST. LIKE MENTIONED EARLIER... HPC HAS VERY LITTLE CONFIDENCE IN THE QPF FOR DAY 2. HPC FOLLOWED THE NHC TRACK AND THE 50 KT 250 MB JET STREAK WITH THE 00Z GFS OVER THE MID-ATL TO COME UP WITH THE BROAD .25 AND .50 INCH AREAS OVER VA/MD/DE AND NC. TERRY/MUSHER GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 02/12Z 0.01 224061 229069 234074 247083 260093 274101 283100 288099 293097 297090 299088 302084 301081 296075 288071 275062 268056 263049 257033 254028 251026 241026 233027 228029 0.01 427610 423618 420625 419631 411650 387693 367711 354722 346726 338729 326735 315742 290761 275772 248793 240801 237812 240820 248830 251842 254856 266870 274879 280904 278946 272975 271988 266991 258993 250993 244992 241993 239995 239998 245004 256008 277018 281019 286015 289012 291004 295989 301980 312961 317951 323938 326924 328911 329904 330897 332892 336886 343875 347867 353855 360841 363835 366830 373819 382806 389796 404777 421751 429739 437726 445712 447708 468675 475647 474641 473634 465628 460631 455635 452639 450638 450635 451628 451606 448599 440597 0.01 541192 536176 531164 523151 515140 504132 499129 496128 492128 491132 490137 492144 503154 507159 511165 518176 526188 530193 534196 537197 539194 541192 0.01 456020 466038 474043 482047 484058 489080 500107 509111 512106 511098 505070 501045 501015 499974 495963 492955 489948 486942 483936 478931 469922 466919 463915 463909 462892 460882 459875 453863 449854 447843 445836 440829 436826 432827 430829 426835 425841 423855 422871 420876 414879 410884 408891 407897 408908 411927 417946 428973 437987 447995 456020 0.01 480146 481140 480136 476126 475123 475116 474110 470107 465101 463091 462081 459076 450075 447076 444079 442085 442091 442104 440107 437106 433099 429097 426099 423108 421111 417111 414104 414099 411095 409091 407089 402088 398089 393087 391085 389083 388078 388068 386061 381053 378050 375049 371049 367050 361060 360066 361070 364077 366086 371092 377094 381097 381101 380105 378108 373114 369120 369129 371137 371143 369147 364153 362155 362160 365173 367176 372179 377182 381183 386183 393181 400181 407178 410173 411166 412156 412150 408144 407141 406136 405133 406129 408125 425123 430122 432124 434129 435138 439146 440151 440157 440168 439180 440191 441196 441204 440210 436212 434212 432216 429223 431225 435225 442223 445221 447217 446213 447208 449200 453190 456184 462178 466169 473163 476159 478153 480146 0.25 367813 376798 398769 423732 442697 446685 448678 446667 443663 440657 436648 431646 426648 420657 412672 398715 389742 384758 373780 364805 362811 362816 367813 0.25 486993 486981 484971 479957 476949 472943 469938 465935 460932 457931 453932 450935 449938 450948 455964 460980 465993 472005 476009 480009 482007 485999 486993 0.25 448898 447890 443888 440888 438890 428897 424900 422904 420915 421923 423930 427938 431940 435939 439935 441931 444921 447910 448898 0.25 316811 323803 326801 330799 337796 345790 356780 363767 365756 364749 361745 356741 345744 329748 322751 316755 309762 304768 297779 291792 288794 284795 277795 270796 261799 256803 253810 253818 256828 261836 263845 264848 267850 274848 285840 308820 316811 0.25 395165 395161 395158 395154 395153 392150 389147 387149 389152 390153 389154 388157 385160 384163 384167 385167 387169 390169 392169 393168 395165 0.25 340841 338836 333837 325840 321842 317842 312841 309839 306842 304848 302863 301878 300891 297906 296922 294937 291950 289956 288960 288965 290968 294968 298964 306953 310944 316911 319882 321867 324861 328855 335848 340841 0.25 226054 234061 242070 252077 263084 274088 283089 287087 286083 283081 280077 269069 259063 250056 240048 235045 229045 226045 0.50 413710 426684 429679 429673 425667 421670 411698 407712 409715 413710 0.50 416737 424717 422713 417717 404732 400739 397746 397751 399755 402755 405752 409746 416737 0.50 478990 478983 478976 475964 472956 467948 463945 459943 455946 455951 459963 462971 464979 467987 470992 474995 477994 478990 0.50 359758 356752 353750 343751 332755 321764 316774 314778 316781 321787 330789 341787 349780 358766 359758 0.50 304907 303917 304919 306916 311898 311893 308893 304907 0.50 281816 278810 272807 266807 262808 259811 257816 258820 260824 263829 266835 270840 273838 275836 279830 281826 281818 281816 0.50 277084 277080 275078 266072 261069 253063 248059 240054 237052 234052 234054 238060 245065 250070 256075 264079 272083 277084 1.00 352758 350756 348757 347757 345758 342759 342760 340761 338764 336766 336768 336770 336774 338776 339776 342776 344775 347773 349771 351767 352766 352762 352758 24HR QP VT 03/12Z 0.01 224070 231077 239083 244087 250089 256092 262095 271102 280103 282097 286094 288094 299094 302097 301101 306105 310104 311102 313100 317101 323104 330105 335109 337113 346115 349118 351124 354127 356128 365131 372132 379131 384129 386127 388124 391119 395117 399119 405122 409122 416123 419126 417132 415138 415142 417144 420144 422143 425136 428129 433124 435120 437120 441120 442125 441130 439132 435136 434142 435148 438154 443160 447166 446172 445175 441181 438199 437208 438213 441211 448199 452192 457185 462182 465176 469167 472160 474152 473145 490146 492144 492141 489135 485128 482126 483121 488117 491112 491101 488090 485077 484071 485067 488059 489053 488047 486038 482030 478025 470014 461004 458002 454002 451003 448007 449013 449016 452022 455026 458033 461039 465046 468051 468054 471059 471062 470070 468073 463076 459077 453076 450076 447072 444068 439068 441072 444076 448078 450081 458084 461088 460092 455093 452090 448090 439088 435090 431089 426087 422092 418099 415099 412094 408091 404093 401099 400093 403087 407084 407076 405069 403066 399065 371059 354072 343067 335068 330069 322078 322082 319082 316081 314079 304072 297069 292066 280064 272063 269062 266060 263059 258055 250051 227043 0.01 540207 540201 536202 534199 532193 529187 523186 520188 517195 515199 513209 513213 514218 516223 521235 522246 519247 516242 509232 504230 500233 496236 493240 475242 466248 464251 467255 473264 472276 476288 478293 480297 483298 488299 490303 489308 489313 491318 494323 498324 0.01 481940 488933 492913 491874 485819 466779 448770 436780 422797 420801 417808 413818 405837 400862 398871 395884 395896 395909 398925 401936 401939 404942 407946 411948 416943 420932 421919 423918 425926 432933 443950 447953 450955 453955 466952 475946 481940 0.01 421690 417682 415675 413673 411674 405678 403683 400689 395700 393706 389711 382721 376729 366739 358744 351748 346753 338761 327768 315774 306778 295782 282786 274788 263790 257791 251794 246798 242802 240805 239811 240821 242827 246832 253836 262838 273838 276840 279845 282851 284857 284869 284879 283890 284902 286904 289902 291900 292910 292918 293926 295929 295934 295938 290948 286956 281964 278968 274971 268973 263972 252971 243976 242981 245986 253991 262992 272988 278988 282990 288994 294003 298007 303004 306000 308994 308987 307979 304966 305959 304951 303938 304927 308916 310907 311892 312867 310845 311840 313838 316837 323836 328837 337839 343839 349839 366823 372815 379806 384799 391788 396778 401766 404753 408742 416719 419704 421696 421690 0.01 452863 450862 448864 447865 445867 443869 440871 438873 440872 443872 446871 449869 450868 451865 452863 0.01 383108 384104 384101 380103 375105 372103 372092 370085 367084 365086 366093 363096 356096 350097 348098 348103 350108 354113 358116 363118 367117 371111 376110 380112 383108 0.01 319807 318804 318803 317804 315805 313807 311809 311810 311811 314811 317810 319807 319807 0.25 519273 520266 520262 514257 510250 507245 505242 502244 500247 500255 496259 493271 493277 495280 500286 507287 513284 517276 519273 0.25 478830 475812 466795 460796 453807 439813 428819 418839 424846 434842 441832 449831 456837 461860 468881 474883 477882 479879 480871 480860 480853 479842 478830 0.25 456938 455930 453921 449908 437889 425884 423898 433913 438923 445942 451943 454943 456938 0.25 399726 397726 392729 383735 365746 356750 349756 344763 340770 337778 337781 339783 356781 359781 362785 364791 366793 371794 376790 381783 390768 393760 395750 398732 399726 0.25 379079 378075 375074 374075 375079 375080 378080 379079 0.25 296826 293822 289819 285816 282812 279805 276801 271798 266798 259800 256803 253809 252814 252819 254824 259827 263829 273832 283831 288835 293837 296831 296826