FXUS04 KWBC 022218 PAA QPFPFD QUANTITATIVE PRECIPITATION FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 517 PM EST FRI APR 02 2004 FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION VALID APR 04/0000 UTC THRU APR 06/0000 UTC REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR DAY 1... UPDATE...NOT A LOT OF DIFFERENCE BETWEEN THE 1200 UTC AND 1800 UTC MODEL MASS FIELD FCSTS. AS A RESULT CHANGES FM THE PRELIM TO THE FINAL DAY1 PRIMARILY REFLECT CURRENT OBSERVATIONAL DATA. THE QSTNRY CLOSED LOW IN THE E WL FINALLY GET A BOOT ESEWD THIS PD FM THE PROGRESSIVE NRN STREAM..BUT THE SAME THING CAN'T BE SAID ABT THE SRN GT BASIN SYS..WHICH WL RMN CUT-OFF NR THE AZ/OLD MEXICO BRDR FOR THIS ENTIRE PD. ...TX WWD INTO THE SRN ROCKIES/SRN GT BASIN... THE MDLS ARE IN EXCELLENT AGREEMENT IN THEIR HANDLING OF THE STG..CLOSED MID/UPR LVL CNTR NR THE AZ/OLD MEX BRDR..WITH ALL OF THEM KEEPING IT STNRY THRU THE PD. WITH NO KICKER EVIDENT IN THE SRN STREAM..THIS IDEA OF KEEPING IT STNRY SEEMS QUITE CORRECT..AND XPC THERE TO BE WIDESPREAD RAINS AND HIER ELEV SNOWS ASSOCTD WITH THIS SYS FM SERN CA EWD INTO THE SRN ROCKIES AND TX. THE ACTIVITY OVR THE SRN GT BASIN INTO THE SRN ROCKIES WL BE SUPPORTED BY COLD MID LVL TEMPS/MID LVL DYNAMICS AND SOME UPR DIFL..WITH LOW LVL UPSLOPE FLO AIDING THE PCPN POTNL PTNS OF SERN CO INTO ERN NM. AXIS OF STGEST ESELY LLJ SUGGESTS HVIEST PCPN WL OCCUR FM NWRN TX INTO NERN NM AND SCNTRL/SERN CO..PRETTY MUCH IN LN WITH THE MDL QPFS. HERE..XPC SOME WTR EQUIVALENTS THIS PD TO EXCEED 2 INCHES..IN WHAT WL BE A RATHER LONG DURATION EVENT. BACK IN AZ AND EXTRM WRN NM..CONTD INSTABILITY ACCOMPANYING THE MID LVL CNTR WL RESULT IN WIDESPREAD RAINS..BUT WITH A TENDENCY FOR SOME OF THE HVIER AMTS TO OCCUR VCNTY OF THE MOGOLLON RIM..UNDER LGT SLY TO SSELY LOW LVL FLO REGIME. HVIER GFS QPF PREFERRED HERE. AND FINALLY..STILL DON'T HAVE A LOT OF CONFIDENCE IN THE VRY HVY GFS QPF SOLN OVR SCNTRL TX..IN SPITE OF SOME SIGNIFICANT CNVCTN WHICH IS GOING ON THERE NOW. THE GFS SEEMS TO BE CONTAMINATED BY GRID SCALE FEEDBACK PROBS..SO ITS HVY QPF IS SUSPECT..ALTHO AS USUAL THE ETA SEEMS TO BE UNDER DOING THE QPF. ONCE THE VORT LOBE WHICH IS SUPPORTING THE ONGOING CNVCTN LIFTS NEWD THRU THE REGION ERY TNGT..BELIEVE CNVCTN SHLD BCM MORE SCTTD..IN WHAT WL BE A SOMEWHAT UPR DIFL REGIME WITH SOME RATHER WK GULF LOW LVL INFLO. THUS..MANUAL QPF IS NOT AS HVY AS THE GFS QPF..BUT HVIER THAN THE ETA. ...NERN STATES... THE SEMI-PERMANENT MID/UPR LVL SYS WHICH HAS ANCHORED ITSELF OVR THE MID ATLC STATES PAST SVRL DAYS WL FINALLY GET SHOVED ESEWD THIS PD BY THE STS NRN STREAM S/WV DROPPING SEWD INTO THE GTLKS. LOW LVL INFLO WHICH WL BE WKNG AND LIFTING NWD WL SUPPORT SOME GENLY LGT RAINS IN ME ERY IN THE PD..BUT OTRW XPC ONLY GENLY LGT RAINS WRN NY STATE SWD INTO WRN PA IN DVLPG DEFORMATION ZONE BTWN THE SYSTEMS ON SAT..WITH SOME LGT SNOWS LIKELY TO ACCOMPANY THE NRN STREAM SYS THRU THE GTLKS ON SAT. MDL QPFS SIMILAR AND LOOKED OKAY. DAY 2... THE ETA IS FARTHER SOUTH WITH THE SWRN U.S. UPPER LOW THAN THE GFS...WHICH IS SUPPORTED BY THE UKMET. THUS HAVE USED THE ETA FOR THE MANUAL QPF. ACTUALLY THE ETA AND GFS BOTH HAVE QPF MAXES OVER ERN NM...BUT THE GFS HAS OVER TWICE AS MUCH PCPN FCST AS THE ETA. LOOKING AT INDIVIDUAL 6-HR PERIODS IT IS APPARENT THAT THE GFS ONCE AGAIN SHOWS GRID-SCALE FEEDBACK PROBLEMS BUT AT LEAST THE QPF MAXES ARE IN ROUGHLY THE SAME LOCATIONS IN BOTH MODELS. IN ANY EVENT...WITH HIGH PRESSURE SLIDING SWD THROUGH THE PLAINS...SOUTHEASTERLY FLOW WILL MAINTAIN MOISTURE FLOW FROM THE GULF WHICH WILL CONTRIBUTE TO QPF APPROACHING 3 INCHES OVER SERN NM. WITH THE SYSTEM IN THE EAST...HAVE OPTED FOR A MODEL QPF BLEND ACTUALLY ENDING UP MORE LIKE THE GFS DUE TO DOUBTS AS TO WHETHER THE CLOSED LOW WILL DROP AS FAR SOUTH AS THE ETA SUGGESTS. THUS ANTICIPATE A LARGE AREA OF THE NORTHEAST TO EXPERIENCE .25 INCH OR GREATER PCPN...IN THE FORM OF RAIN CHANGING TO SNOW AS THE VERY COLD AIR SWEEPS EWD THROUGH THE UPPER OH VALLEY AND CNTRL APPALACHIANS. DAY 3... MANUAL QPF AGAIN LEANED MORE HEAVILY TOWARD THE ETA OVER THE WRN U.S. THIS PERIOD...DUE TO CONTINUED SUPPORT FROM THE 12Z UKMET. STILL ANTICIPATE A LARGE AREA OF DECENT PCPN FROM .25 TO .50 INCH EXTENDING FROM SRN/ERN NM DOWN THE RIO GRANDE VALLEY AS HEIGHTS SLOWLY FALL AND ENERGY INTERACTS WITH MOISTURE CONTINUING TO BE PULLED IN FROM THE GULF ON SOUTHEASTERLY FLOW. IN THE EAST...HAVE GONE MORE OR LESS WITH THE GFS DUE TO LINGERING DOUBTS AS TO THE FARTHER SOUTH ETA TRACK WITH THE UPPER LOW. THUS EXPECT MOST OF THE PCPN TO OCCUR OVER INLAND NEW ENGLAND RATHER THAN THE SRN COASTAL PORTIONS. MUCH OF THE PCPN OVER ERN NEW ENGLAND IS EXPECTED TO CHANGE OVER TO SNOW AS THE COLD AIR SWEEPS IN...LEADING TO THE POTENTIAL FOR A SIGNIFICANT EARLY SPRING SNOW EVENT PARTICULARLY IN THE HIGHER ELEVATIONS OF NRN VT/NH/ME. TERRY/MAUSSER GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV 24HR QP VT 04/00Z 0.01 492664 490659 488653 483647 482647 478648 472654 468650 465643 461637 457631 452625 447622 444621 442623 436630 434637 434644 435660 434666 432672 428686 427689 427692 432693 434694 433698 432703 428715 428723 432731 441739 442741 442745 441749 438756 435763 431767 424770 420771 416770 412768 409764 409759 408752 406745 403741 398737 396736 392737 380761 379767 378771 380775 382778 382785 381790 379794 376799 372804 365812 357823 354828 352836 352842 354846 358847 362846 367841 375832 382825 385822 391819 417807 424805 432803 437803 442807 446813 449823 448830 445836 440845 437857 435866 435872 437878 441882 446884 453882 457882 458884 465897 467905 468911 467921 468927 470931 473934 476936 476940 473952 469969 468977 468988 466995 466000 467005 469009 472009 477003 483991 488978 498954 502944 504937 505929 505921 504911 500907 497907 494905 495900 499884 501877 502868 501863 499858 495853 491853 489851 489847 488830 485825 482823 479825 475829 471833 470831 469826 470819 473813 476804 477796 478789 477780 474768 470762 472754 478741 483727 488712 491696 492679 492664 0.01 438096 440088 440080 437069 434059 430053 424048 415045 400034 392029 388028 385024 373015 361002 351989 340974 332961 327955 322948 315941 308937 292933 287934 283936 278938 275939 268943 266950 266953 270958 273960 275964 272972 271982 273986 275987 276993 277001 280004 285004 293001 297002 297008 297013 296018 293025 291035 293043 296046 299048 302049 305052 307057 308062 308067 305072 299078 295083 292090 290100 290106 295117 298124 300132 301139 302142 309148 314154 318159 324165 331169 338174 346179 357183 366186 373189 376188 378184 399151 396139 393131 392127 394123 396120 398116 410099 414090 415087 418090 423096 429100 436100 438096 0.01 355752 354749 350747 345749 340753 333760 328767 324776 323784 323790 327795 332793 337788 341782 347774 349771 353765 355762 356756 355752 0.25 469669 465663 460657 454650 451650 448651 445655 445660 447668 450672 452683 455688 458692 464693 467690 469679 470672 469669 0.25 408061 409056 408053 405049 399044 395042 389039 381035 374031 368026 356010 345998 338992 335990 329989 323991 321995 320004 318015 318029 319036 319039 321042 326047 332055 333058 333062 326069 324072 322076 319081 316083 313086 310091 307098 305104 305109 306116 308119 313127 316131 319133 329134 338136 344139 350141 358142 361141 364137 367126 369122 372118 377116 378112 376109 375102 375095 378087 381079 387072 394068 408061 0.25 315980 315975 314970 311964 309958 304952 299950 295949 291950 286955 283959 281966 282968 285969 288975 292983 298983 301982 306982 310982 314981 315980 0.50 397057 397053 396049 393047 384043 378039 370033 359019 353012 347006 339001 336000 331001 326022 327028 328035 329040 332045 335047 342051 349057 354065 360070 369074 375073 378070 381066 384063 391060 397057 0.50 349120 351114 349109 346099 343089 338081 333079 329082 327088 325092 324095 321098 318103 318106 320111 323114 332116 340121 345122 349120 0.50 304972 304969 303966 301963 301962 299960 298958 296957 295956 292956 289957 288958 287961 286962 287965 290968 291969 292970 294973 297976 300974 302974 304972 1.00 381054 381049 377047 369040 364033 359026 353020 348017 345016 343020 345027 346041 349048 355056 358058 362058 366057 370054 375052 378052 381054 381054 1.00 341109 342106 341102 341099 339095 338094 335094 334095 334099 334102 335104 335105 337109 340109 341109 1.50 370047 368043 365040 363037 360032 357029 354026 351025 351027 351034 352037 354044 355048 358052 364053 369050 370047 2.00 364047 364044 363043 362040 360038 360037 357033 355037 356040 358043 358044 361046 362047 363048 364047 24HR QP VT 05/00Z 0.01 526686 528690 534712 536731 528758 510793 503806 496820 487834 477846 468856 456867 450872 444876 437878 431879 426878 420875 407872 403868 399862 395855 391850 388846 383842 376841 369843 361844 356845 353841 352837 351833 352828 352822 354817 357811 362805 367801 373796 378791 379785 379781 377778 373773 371769 370764 370756 373750 378743 384731 388725 391722 406712 415706 422702 427701 431699 433695 429679 430666 431656 439641 450626 466614 482611 499620 501622 503626 507634 0.01 380206 398215 419214 440210 454199 460183 470165 481142 489123 485104 475084 465088 453119 442134 432144 427151 419159 411165 400167 392168 387171 387175 390178 396183 399185 401190 400193 396191 388186 380179 372171 370166 368159 368153 369144 373139 378134 387127 397119 410114 412112 414108 414103 413099 410093 406087 399079 396074 395069 397063 400057 404052 403047 400038 394034 380029 371023 361018 352014 341010 329005 324001 319995 308971 303960 300956 295954 292957 291961 287965 282961 276958 269956 261957 254961 251964 249970 248977 248983 251994 257004 261013 264025 266033 269039 277049 281054 283059 288072 292081 298091 304099 307110 312124 317130 322134 333139 336141 337144 335149 328161 326168 328173 337179 347184 354187 359190 365193 370198 380206 0.25 495716 501710 499694 495684 496678 501670 506665 505659 494650 491647 475639 458646 449654 444666 449675 462684 466686 475690 483695 485704 489716 495716 0.25 470786 483770 504745 511727 505719 490737 479752 466752 453748 443747 435746 428742 422740 414738 404744 395751 389757 387762 390764 393767 398768 400775 399780 396784 391789 382796 378803 377812 379817 380818 384820 389820 398819 407816 415810 420807 426806 434807 440809 448807 453804 458799 470786 0.25 382083 381071 381063 381051 379047 375043 369038 361034 343025 335021 329017 321010 314003 302993 286982 280977 275970 271968 267968 261969 259972 258975 259979 265984 267990 267997 270007 274017 278025 282034 288043 308072 317087 319092 322095 332099 341103 348108 352110 359111 363110 368107 372104 376097 382083 0.50 339089 347094 356099 359094 359085 356072 362064 370055 369047 363041 355035 345031 333025 323019 314010 305005 300003 291004 288004 286007 286012 289028 294037 302048 308056 314068 317074 321078 331085 339089 1.00 361051 359047 355043 343038 335033 331031 324029 320027 315024 309025 307028 307033 313042 316046 321050 330056 341059 348060 354059 359057 361054 361051 1.00 345082 346079 344076 343075 341073 338072 337071 333071 331074 334079 338083 343084 345082 1.50 355051 352046 348044 344042 341041 335039 332038 326038 322039 321042 322045 325048 329052 333053 336055 341056 347056 352054 355051 2.00 337043 333043 329043 327044 329048 332050 339053 342054 348053 350051 348048 344046 339044 337043 24HR QP VT 06/00Z 0.01 521674 523684 523692 525702 525711 525716 524725 521739 516748 512753 508758 503764 492774 483780 468789 462792 458794 446797 435798 422803 409809 398816 386821 377823 373821 369815 369810 370806 379798 387792 395787 398783 407774 410769 411765 411761 407754 403749 398746 393746 388744 385741 383736 386725 389711 390704 392698 399680 411657 433621 441607 444602 449596 457591 464590 469591 473592 477595 482597 486601 489602 494607 0.01 342130 358145 375153 382164 388182 405199 416207 422228 435230 454206 472177 479147 479096 475064 453039 439034 433048 431064 433083 427088 427098 430113 429126 419137 414144 407144 403139 405128 413116 415088 415072 415059 410054 405053 401053 395051 387051 381050 376048 376044 377039 378033 378025 376021 373017 370014 368008 366001 359998 346996 343993 340989 335976 330969 326968 322969 312976 308975 304972 295963 287954 280950 273949 268948 263948 258951 251959 246965 246971 247977 249983 249992 253008 257016 263024 277037 282043 288053 301103 303108 306113 310116 317117 325119 334124 342130 0.25 512683 510672 507665 502651 495645 492642 488641 480638 477637 480632 483627 483621 481616 473608 465604 458605 452608 447614 445618 444622 445630 449634 452635 459638 459641 454644 450647 446652 441660 438669 438676 439681 441686 442693 438700 433707 424716 420720 420724 421730 424733 429737 437744 443749 449752 456753 465754 474752 489746 495742 500738 504734 507729 510719 512710 512693 512683 0.25 385114 390094 393079 389073 381074 376076 375079 372090 369096 366098 364104 363111 365118 366121 371123 376124 381122 383119 385114 0.25 364033 363027 360022 353017 345015 337016 330017 325016 322014 320009 317001 313996 300985 295979 291973 286964 280958 274957 269957 265959 261961 258965 257967 257973 259981 262988 268997 272003 281015 286023 291028 301037 309044 312053 313061 312