FXUS04 KWBC 191042 PAA
QPFPFD
 
QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
541 AM EST WED FEB 19 2003
 
FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 20/1200 UTC THRU FEB 22/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 

...UPDATE DAY 1...
NO MAJOR MDL CHNGS. SOME MINOR MANUAL QPF CHNGS DUE TO
ONGOING RDR/SATL TRENDS.

DAY 1...

...NWRN U.S....
MDLS CONT TO TREND TWD MORE DIGG AS A STG PAC SHRTWV RIDES
INTO THE PAC NW AND THEN SLIDES SEWD INTO SRN CA BY THE END OF
THE PD. SOME OF THE ENERGY IS XPCD TO SPLIT AND MOV EWD INTO THE
NRN ROCKIES. ALTHOU THE MIDLVL DYNAMICS ARE QUITE STG...FOR A
WHILE...MSTR IS LIMITED AND THE MDLS ARE SHOWG VRY WEAK
OROGRAPHIC FORCG. THEREFORE...PCPN SHLD BE RELATIVELY LGT THRU
THE REGION. HIER ELEV SNWS ARE LKLY.

...SRN ROCKIES EWD INTO TX AND THE SRN APLCHNS...
VRY COMPLEX SCENARIO THIS PD AS WE BEGIN TO SETUP FOR WHAT
LOOKS TO BE A RATHER WET PD BEYOND DAY 1. MSTR THRU THE SRN U.S.
CONTS TO SLOLY BUILD...WHILE THE MDLS SHOW SVRL RELATIVELY WEAK
MIDLVL IMPULSES MOVG THRU THE MEAN FLOW. THE KEY TO THIS AREA
SEEMS TO BE LINKED TO THE DVLPMENT OF THE DEEP MIDLVL LOW OVR
SRN CA BY THE END OF THE PD AND HOW THIS AFFECTS THE UPSTREAM
HGT FIELDS. THE ETA SEEMS TO BE HNDLG THE SYS DIGG INTO CA BETTER
AND HAS BEEN MORE CORRECT THE PAST FEW DAYS...EVEN THOU THE
WHOLE SCENARIO HAS BEEN RATHER FLUID. OUR CONFIDENCE REMAINS
ON THE LOW SIDE DUE TO THE DAILY CHNGS SEEN IN THE MDLS. MSTR
THRU THE SCNTRL U.S. IS NOT THAT IMPRSV ERLY THIS MRNG AND THE
GFS WAS A LITTLE TOO WET AFTER SEEG THE LATEST SSM/I & GOES PWS
LOOPS. WL LEAN TWD THE LGTR ETA QPF. ONE SHRTWV WL SHEAR EWD
FM THE CNTRL/SRN PLNS INTO THE OH VLY WITH SOME MOD RNS ERLY
THIS MRNG IN THE AXIS OF THE LLJ AND MOD LOLVL THERMAL FORCG. LGT
RNS SHLD SPRD NEWD INTO THE OH VLY LATER TDA AS THIS SYS SLOLY
WEAKENS. THE SFC/8H FNTS LYG ACRS THE SRN PLNS WL SINK INTO TX
TNGT WITH MSTR CONTG TO BUILD AND POOL ALNG THE BNDRY. THE MDLS
SHOW SOME INCRS IN LOLVL CVRG LATER TNGT THAT SHLD SUPPORT
RW/TRW OVR SRN TX LATER TNGT. ALSO...THE LOLVL FLOW WL CONT TO
BACK AND FEED MSTR UP THE RIO GRANDE VLY INTO FAR WRN TX AND
THE SRN ROCKIES. THIS SHLD SUPPORT SOME UPSLOPE RNS OVR THE
LWR ELEVS WITH HIER ELEVS SNWS LATE TNGT. 

...SRN FL...
MDLS SUPPORT INCRSG SERLY FLOW FM THE CARIBBEAN THAT WL BRING
DEEP MSTR INTO THE REGION. THIS SHLD FOCUS ALNG THE SERN CSTL
AREAS AND SUPPORT SOME LGT RW.

DAY 2...

THE RETURN OF GULF INFLOW/HIGHER PWS  INTO THE WRN GULF COAST
REGION IS SETTING THE STAGE FOR AN OUTBREAK OF SIGNIFICANT RAINS
IN E TX/AR BY THE END OF THIS PERIOD. 

I HAVE GENERALLY GONE ALONG WITH THE ETA QPF OVER THAT OF THE
GFS...AS PER THE LATEST MODEL DIAGNOSTIC DISCUSSION.  AN
EXCEPTION TO THIS THINKING IS  THAT I INCREASED CONVECTIVE QPF
AMOUNTS IN TX FOR THE PREDAWN HOURS FRI. FOR THAT TIME...THE GFS
FORECASTS  DEVELOPMENT OF A SLY LOW LEVEL WIND MAX INTO SE
TX...ACCOMPANIED BY PWS OF ABOUT 1.5 IN.       

ONSHORE FLOW WILL BRING SOME MODERATE QPF TO THE WA/OR
CASCADES/BITTERROOT RANGES BEFORE WEAKENING THU NIGHT.     
OTRW...EXPECT ONLY LIGHT SNOWS OVER THE UPPER GREAT LAKES IN
CONNECTION WITH A WEAK WAVE ON AN ARCTIC FRONT.  

DAY 3...

I CONTINUE THE SAME REASONING AS DAY 2...PLAYING UP A PRIMARY
MAXIMUM OF CONVECTIVE PCPN INLAND FROM THE GULF COAST.  A
SUPERCHARGE OF VERY HIGH PWS FOR LATE FEB NWD INTO THE GULF
COAST REGION SHOULD SATURATE AT FAIRLY HIGH THICKNESSES. THIS
WILL HELP RELEASE CONVECTION FAIRLY FAR S.  IN ADDITION...A CLOSED
UPPER LOW WILL BE OPENING UP/EJECTING OUT OF THE SWRN STATES
SUPPLYING POTENT UPPER DYNAMICS FOR CONVECTION.  SOME OF THE
CONVECTION IN THE PRIMARY MAXIMUM SHOULD BE STRONG...REFER TO
SPC CONVECTIVE OUTLOOKS. 

A SECONDARY MAXIMUM OF PCPN IS EXPECTED THRU THE OH VLY
ALONG/JUST N OF A POLAR FRONT AS A FAIRLY VIGOROUS SURFACE LOW
MOVES NEWD OUT OF THE LOWER MS VLY INTO THE LOWER  OH VLY.

PACIFIC NW PCPN SHOULD TAPER OFF FRI WITH DECREASING ONSHORE
FLOW AND SLOWLY BUILDING SURFACE PRES. MOSTLY LIGHT SNOW IS
EXPECTED IN THE LOWER LAKES THU AS A SURFACE WAVE RIPPLES EWD
THRU THE ST LAWRENCE SEAWAY...ALLOWING THE FRONT AND ATTENDING 
SN SHOWERS TO SURGE S.      

  
ECKERT/FLOOD

GRAPHICS AVAILABLE ON THE WEB AT http://www.hpc.ncep.noaa.gov

24HR QP VT 20/12Z
 0.01 483687 478668 475660 471652 466645 462643 458643 455645
453648 
      452660 453673 456688 457703 459719 460734 461747 461761
461777 
      461783 464791 467796 471798 474797 477794 480790 482783
484776 
      487763 488749 489733 488719 486705 483687 
 0.01 404832 407812 409791 409775 408760 402750 392751 383756
375765 
      369775 360799 356811 352822 345842 337860 332870 326880
321889 
      316900 312909 309918 303937 299947 294955 289965 286970
282974 
      272979 270981 268986 268988 271994 276002 283008 290012
300016 
      304020 306027 308052 309067 308081 309089 312093 315097
318098 
      322096 323093 323088 324085 330088 332092 334096 337099
340101 
      343100 340080 342079 347082 352085 356082 358076 361071
362067 
      361065 362061 367059 370056 373051 374047 373043 369042
365045 
      355044 344040 340038 338033 332015 329003 328994 328986
330975 
      333966 337960 345954 348951 356948 363948 368950 378951
384943 
      387929 387923 388915 390904 393892 395880 398866 401855
404843 
      404832 
 0.01 279800 277797 274795 266793 261792 256795 251797 247797
243798 
      241800 242803 240805 235808 238814 244821 248822 251822
258817 
      265811 275808 278807 279803 279800 
 0.25 530204 531199 530194 528189 525183 521177 516171 510166
508165 
      504164 499165 493165 487163 481160 478164 480168 483173
486176 
      492178 498181 503182 511189 517196 525204 530204 
 0.25 514266 516260 515253 513247 506232 499218 494212 488208
480207 
      475209 469213 464215 452219 449221 451224 455224 459225
463226 
      466224 471221 476220 483222 489229 488233 483236 479234
475233 
      473234 470237 468237 460236 455237 451238 451240 459242
466244 
      474248 479253 484259 494272 503282 506284 508282 508273
506269 
      507266 508264 512267 514266 
 0.25 425242 426239 425238 422236 419236 416236 416236 413236
410236 
      407237 407237 404238 401239 401243 403245 405246 409245
409245 
      412244 415243 415243 418243 421243 424243 425242 
 0.25 410226 412223 412219 410217 407217 406217 407218 408221
407225 
      408228 410226 
 0.25 442223 439221 437222 439226 442223 
 0.25 377909 379897 380884 381875 380870 374870 369873 364878
360887 
      356895 355902 354911 354914 355925 359927 364926 370925
375920 
      376916 377909 
 0.25 334916 329906 327905 324906 321910 312928 304946 300956
297966 
      294976 289984 287986 286989 287993 291996 296998 304997
304992 
      301988 300984 300979 302974 305971 314954 325937 330927
334918 
      334916 
 0.25 336062 338058 337055 335051 332048 329044 327039 325035
323030 
      320026 318030 317036 316042 318049 319052 321058 324062
327062 
      333062 336062 
 0.25 262801 261801 258801 256802 253803 251805 250806 252807
254806 
      257805 259804 262802 262801 
 0.50 506277 504272 502266 499260 497256 494252 492248 489244
487243 
      484246 485250 488256 490260 492264 494268 498274 502278
506277 
 0.50 490215 488214 485212 482212 479211 478212 479215 481217
484218 
      487218 490215 
 0.50 373902 373898 371896 368899 367900 366902 365904 364906
363908 
      362912 362912 362912 364915 365916 368914 368914 370910
370910 
      371906 372904 373902 
 0.50 313946 321936 326928 326921 321921 316927 312935 308946
307952 
      309951 313946  
 
24HR QP VT 21/12Z
 0.01 532219 536207 529170 516145 508123 506100 508076 509060
508048 
      507028 506022 495004 471002 457024 459044 462053 466064
473082 
      477090 478098 478103 476106 467108 461106 458104 451100
446098 
      441097 432097 428099 425102 422106 421114 425124 432129
437132 
      442133 445134 446140 445146 441148 437153 435156 437160
439164 
      445170 451177 463179 474182 479184 482187 483192 480195
466200 
      448205 433212 427215 419220 416221 413225 413231 416234
423241 
      428248 446251 454252 464254 469254 474257 480263 487273
492282 
      498288 502292 506292 510289 513284 518275 518268 522257
521250 
      520243 515233 510222 506214 505207 506205 509205 515210
520214 
      526217 532219 
 0.01 501803 498744 488739 478755 467778 455821 450849 449863
447873 
      448879 447884 448897 453908 455914 456921 458935 459942
461945 
      464959 468970 469976 473976 476979 480978 485976 487972
492963 
      496954 498949 499944 499930 498916 500904 499891 499879
500863 
      499851 500846 500839 500813 501803 
 0.01 364861 363855 360852 357850 354850 349852 344858 341861
337865 
      331870 323885 322889 317901 306910 297914 290928 280938
273942 
      260950 258965 266984 267006 269014 282030 286047 295061
298074 
      298091 300098 307113 318118 327114 335108 341098 345088
348073 
      350059 355049 361030 357020 358006 366995 372993 374988
375978 
      375966 374956 373946 370938 363919 361913 360907 360898
360888 
      363879 364869 364861 
 0.25 516253 513242 509231 504220 497209 495206 490203 484202
479204 
      471206 462208 453210 443214 436217 433220 433225 436230
440232 
      444236 446241 450244 456245 465247 476251 479253 484259
489266 
      496276 502280 505277 508269 510263 512259 516253 
 0.25 518191 520184 519179 513171 509165 502159 497155 492148
489143 
      483138 479136 476137 480144 483151 481152 476151 471146
465143 
      462144 462147 462151 464156 475164 489173 500183 508188
514191 
      518191 
 0.25 339001 345992 353982 360968 362961 360951 359944 356932
351921 
      347917 345915 342916 333922 328924 322923 318922 311924
304930 
      298938 291943 282948 277951 274955 270963 272972 273985
273998 
      275004 276008 282014 290020 293025 293031 294037 295044
300049 
      304055 305059 306068 308073 311083 312085 315090 319091
322084 
      320070 318064 315059 313053 315045 320037 327032 337031
340028 
      340019 338010 339001 
 0.25 294049 294046 293046 293046 293050 294051 294049 
 0.50 503271 504265 504261 504248 506247 509244 508239 506233
502224 
      496215 491208 485206 480206 464210 449216 442220 442223
444226 
      454229 457233 454239 458241 467244 475246 482252 494267
499273 
      503271 
 0.50 328001 329998 332988 338980 348968 353953 348936 336936
331938 
      326937 323934 317933 311935 302943 293950 284958 280962
277967 
      277973 278981 280995 282003 286007 291009 295012 298017
303024 
      308025 312022 319010 328001 
 1.00 498265 498264 496259 496259 494254 494253 492248 492248
489245 
      487243 484245 486249 486251 488254 489256 490258 493260
495263 
      495264 498265 498265 
 1.00 298958 291964 288972 288980 289988 293993 305992 316984
325970 
      324955 317950 312949 305952 298958 
 1.50 314967 314964 312961 312961 309960 307962 306962 304965
303965 
      302968 301969 299972 298973 298976 300979 300979 303980
305978 
      305978 308975 309974 310973 313971 313970 314967  
 
24HR QP VT 22/12Z
 0.00 427241 426241 425232 430228 436226 451223 454221 457218
460209 
 0.00 342033 334037 327048 322061 
 0.01 507660 505651 501642 494627 483615 479612 474611 470613
467616 
      464622 463628 461658 459685 458693 456699 449712 443723
440734 
      439741 439750 438766 438791 438808 438816 438823 439831
440841 
      442848 445856 450861 451866 454881 456888 459896 464896
467891 
      474876 477861 480849 481837 484819 485802 487774 488767
489758 
      494744 501719 504703 507687 508673 507660 
 0.01 525178 527170 528161 527151 525147 519127 510106 505090
503075 
      501060 501043 499029 498018 493002 488991 482980 476972
470966 
      463961 458956 455952 454947 454941 457936 461927 463920
464914 
      461906 457902 451897 443896 437899 431906 425917 420927
416936 
      413945 412952 414957 418961 419964 418974 418987 419004
419011 
      419017 419025 421030 424041 429065 430073 426074 421072
416076 
      414082 413090 414099 417109 421119 426130 431147 435166
441179 
      448184 455183 463184 467187 471192 475197 478203 476208
467212 
      461210 453210 441209 433211 427217 424225 423230 424234
426239 
      431242 438242 458235 475229 482230 490234 501238 505238
510235 
      513229 513225 513209 512196 511187 516186 521183 525178 
 0.01 423749 421744 417740 413738 410733 407722 403709 399701
396697 
      393696 390696 385697 374705 371708 368714 362723 355733
346748 
      341759 339766 338773 337778 334782 329791 321798 315801
309802 
      293803 280804 275808 275814 279820 282823 286826 287830
286833 
      281840 280847 279863 275880 268895 257916 251939 253954
258966 
      267978 267983 264989 253008 253024 254038 255042 258046
264052 
      268054 274055 284054 295055 302059 308062 311062 319063
324062 
      333055 339047 342035 342023 342010 343004 344996 348985
355977 
      361969 366960 371950 378932 388909 393897 398887 402878
406868 
      409858 412848 415833 418820 419806 421793 423783 424772
425757 
      423749 
 0.25 492658 490651 486645 482642 479643 477648 477655 477662
477667 
      479675 482683 483687 486690 489687 491683 493678 494672
493663 
      492658 
 0.25 480715 480710 477707 477707 474709 473710 472712 470716
470718 
      469722 468723 467728 467729 468733 468738 469742 472741
473739 
      474738 476733 476732 477728 478726 479722 479720 480715
480715 
 0.25 463776 465791 468793 473777 470762 466764 465767 465770
465772 
      463776 
 0.25 482160 483154 484147 484141 483137 480126 474118 462111
457119 
      457137 464156 467160 472164 478162 482160 
 0.25 407767 404755 400743 396735 391729 383726 377728 373733
364747 
      361755 359762 355777 351796 348805 344811 340815 336816
328816 
      320818 312822 305826 300832 290847 288854 287862 286869
284876 
      281884 278891 271905 268913 267920 264934 262943 264952
267958 
      273962 278967 280970 281974 281982 279988 276995 282999
285001 
      288999 296995 304007 307012 311017 317016 319015 324012
325008