QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
458 AM EST WED NOV 25 2009
 
 
FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID NOV 25/1200 UTC THRU NOV 28/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 
 
DAY 1...

06Z UPDATE...
GENLY SMALL ADJUSTMENTS TO PRELIMS.  INCREASED AMOUNTS ACROSS SE
GA/SRN SC BASED ON SHORT TERM RADAR TRENDS AND LATEST NAM/ECMWF. 
ALSO PULLED .25 INCH SWD SOME ACRS THE MIDWEST BASED ON TREND OF
00Z ECMWF.  

...GTLKS/OH VLY...
TWO SYSTEMS WILL BE AFFECTING THE AREA THIS PD WITH CLOSED LOW
OVER THE MIDWEST REGION QUICKLY OPENING UP TO THE NE EARLY IN THE
PD IN RESPONSE TO STG COLD UPR TROF DIGGING SWD THRU THE NRN
PLAINS/MO VALLEY REGION.  LATTER SYSTEM WILL EVENTUALLY CLOSE OFF
OVER THE MIDWEST WED NIGHT...THREATENING PARTS OF THE AREA WITH
SOME ACCUMULATING SNOWS.  WITH LEAD SYSTEM RAPIDLY
WEAKENING..SHOULD SEE GENLY LIGHT AMOUNTS AS REMNANTS LIFT NWD
ACRS THE CNTL GT LAKES.  SOME VERY SLIGHT DIFFERENCES WITH TRACK
OF TRAILING UPR TROF..THOUGH QPF DETAILS ARE RATHER SIMILAR.  WEAK
COMMA HEAD BAND SHOULD DVLP NEAR THE MID/UPR CIRC WED NIGHT ACRS
SRN WI WITH POTNL FOR SOME .25 TO .50 INCH PLUS LIQUID AMOUNTS. 
SEE QPFHSD FOR DETAILS ON WINTER WEATHER.

...PAC NW...
MODELS SHOW INITIAL LOW PRES MOVING INTO WRN CANADA LEAVING POS
TILTED TROF AXIS ACRS THE NRN PAC AS NEXT UPSTREAM SYSTEM PUSHES
EWD TOWARD THE PAC NW COAST..BUT REMAINING WELL OFFSHORE BY THE
END OF THE PD.  AS A RESULT...SLOW MOVING FRONT WILL GRADUALLY
STALL ACRS WRN WA WED NIGHT WITH BROAD SWLY FETCH HELPING TO
MAINTAIN AXIS OF 1 INCH PWS DIRECTED INTO THE COASTAL
RANGES/OLYMPICS WED NIGHT.   MODELS GENLY SHOW AGREEMENT IN THIS
SCENARIO AND LIKEWISE SHOW REASONABLY SIMILAR QPFS...SO BASICALLY
FOLLOWED MODEL CONSENSUS WITH 1 TO 2 INCH RAINS ACRS THE OLYMPICS
AND SOME 1 INCH PLUS AMOUNTS OVER THE NRN CASCADES.

...FL...
MODELS GENL AGREE ON INCREASING ACTIVE CONVECTION VCNTY OF STALLED
FRONT ACRS FL AS S/WV ENERGY LIFTS ENEWD FROM THE CNTL GULF THIS
PD..THOUGH DIFFER SIGNIFICANTLY ON WHERE HEAVIER AMOUNTS WILL
OCCUR.  PARALLEL RUN OF GFS IS CONSIDERABLY FARTHER NORTH OF THE
OPERATION GFS AND IS IN CLOSER AGREEMENT WITH THE 12Z ECMWF IN
PRODUCING SOME 1 TO 2 INCH CONVECTIVE RAINS ACRS CNTL FL AS
OPPOSED TO SRN FL.  THE NAM DOESN'T SEEM TO BE HANDLING THE HIER
PWS EVIDENT NEAR THE KEYS AND CONSEQUENTLY IS PROBABLY ON THE DRY
SIDE WITH AMOUNTS. FOR NOW HAVE TENDED TO GO MORE WITH 12Z
ECMWF/00Z GFSP..THOUGH CONFIDENCE REMAINS LOW GIVEN WIDESPREAD
CONVECTIVE NATURE OF EVENT.   SOME REASONABLY HI PWS WL BE IN
PLACE..AOA 1.75 INCHES..SO SOME BRIEFLY INTENSE RNFL RATES ARE
LIKELY..AS ARE SOME LCLY HVY RNFL AMTS THIS PD.
 
 
DAYS 2/3...

...PAC NORTHWEST/NRN CA THROUGH NRN ROCKIES...  
  
THE MODELS STILL AGREE THAT A POTENT SYS WILL BE MAKING ITS WAY
FROM THE ERN NOPAC INTO THE PAC NW ON DAYS 2 AND 3...WITH THE BEST
FOCUS FOR PCPN BEING ALONG THE FRONT WHICH  PROGRESSES DOWN THE
COASTLINE AND WITH THE UPPER SYSTEM THAT APPROACHES THE WEST COAST
OF NORTH AMERICA WITH TIME.  THE MODELS STILL OFFER DIFFERING RE
STILL QUITE DISPARATE...BUT H5 PHASING/SFC LOW INTENSITY SEEMS TO
BE CLUSTERING AROUND THE 24/12Z AND 25/00Z ECMWF WHICH MADE MADE A
FAVORABLE ADJUSTMENT TOWARDS ITS OWN ENS MEAN ON TUESDAY. 
REGARDLESS OF WHICH SOLN VERIFIES...THE PERSISTENT/STRONG MSTR
FETCH SHOULD WILL FOSTER ANOTHER INCH OR MORE OF RAFL IN THE WA/OR
COASTAL RANGES...WITH LESSER AMOUNTS INLAND. 

...GTLKS REGION AND NORTHEAST...

TROF AMPLIFYING INTO THE MS VLY WILL SLOWLY SLIDE EAST THROUGH THE
PD...WHILE THE ORIGINAL SFC LOW DRIFTS THROUGH THE GTLKS.  THE
MODELS STILL DEPICT LESS THAN IMPRESSIVE AMOUTNS OF
MOISTURE...ALTHOUGH THE DYNAMICS ALOFT STILL FAVOR WRAP
AROUND/DEFORMATION PCPN WITH INSTABILITY ABLE TO CONTRIBUTE SOME
TO PCPN AMOUNTS.  GENERALLY 0.50-0.75 INCH IS EXPECTED MAINLY ON
DAY 2 HERE...SIMILAR TO THE 12Z NAM/ECMWF DEPICTION.  

ALONG THE ATLANTIC COAST...THE NAM REMAINS BULLISH WITH THE SYS
ALONG THE MID ATLANTIC COAST WHICH IS AN OUTLIER SOLN.  BOTH THE
GFS AND THE ECMWF AGREE THAT A LOW INITIALLY OFF THE CAROLINA
COAST AT THE START OF DAY 2 WILL BE MOVING NORTHWARD EITHER SIDE
OF 70W THAT DEEPENS SIGNIFICANTLY ONCE IT ROUGHLY REACHES THE
BENCHMARK.  WHEN IT DOES...THE ECMWF IS MORE INCLINE TO KEEP SOME
DISTANCE BETWEEN THE LOW AND A MID LEVEL TROF MAKING ITS WAY
EASTWARD ACROSS EASTERN NORTH AMERICA WHILE THE GFS IS MORE INLAND
DUE TO ITS ATTEMPT TO PHASE THE TWO SYSTEMS.  WE TEND TO PREFER
THE ECMWF GIVEN THE AMOUNT OF THINGS NEEDED TO HAPPEN TO
SUCCESSFULLY PHASE THE ATLANTIC LOW AND THE ERN U.S./CANADIAN
TROF. WHILE OUR PREFERENCE WAS FOR THE 25/00Z ECMWF...THE NCEP
MODELS AND NON NCEP MODELS PRODUCE DECENT AMOUNTS OF PCPN IN
ERN/NRN NEW ENGLAND WHETHER THE PCPN RESULTS FROM ONSHORE FLOW OR
MID LEVEL FORCING.

SULLIVAN/BANN

GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV
24HR QP VT 26/12Z
 0.01 524251 522247 520241 518236 515231 513226 511222 508217 
      505211 503206 505202 510203 513205 517210 520214 524217 
      529221 532222 534220 537216 538213 540207 540202 538196 
      535191 531183 527176 522170 517166 505157 497158 492161 
      487166 486168 486173 489180 490190 491193 489196 484197 
      474207 469210 464214 458219 456228 452231 445232 430256 
      430264 432272 429281 427287 428295 432301 436302 439301 
      443299 450294 454296 457300 464304 471303 476300 482296 
      488294 493294 510297 
 0.01 504751 491729 488726 485724 477719 470715 466715 462718 
      457720 452721 444722 426720 418719 415718 411715 407713 
      405710 397706 388709 383711 382734 385737 388738 392740 
      392743 384745 381749 381754 375757 370759 369764 372773 
      376776 380776 397773 406775 414775 418775 421779 420782 
      416786 411788 407792 406797 408800 407804 404809 397817 
      382829 380832 379838 383842 386844 389843 392846 391850 
      385858 383862 383867 384870 388881 391885 395888 399891 
      399903 399907 397913 395917 393922 393927 395930 399935 
      406938 413944 419947 424950 427954 435972 438975 443978 
      452981 461984 471986 477985 481982 484980 487975 486966 
      479957 473950 469945 466939 465934 465929 467923 470920 
      477915 482909 483904 485899 488895 491892 494887 497877 
      499864 500849 499833 497820 493804 502782 505776 506771 
      506766 504751 
 0.01 476683 473675 469670 462666 453664 446664 440667 438672 
      435677 434682 433693 436701 439704 443706 449705 458701 
      461701 462704 466706 470706 474700 476696 476688 476683 
 0.01 362737 362733 359731 355729 347730 329735 318739 310743 
      300748 290752 271764 265769 258775 245788 242794 239803 
      237812 237821 236836 236842 239848 244853 248853 252853 
      260855 276851 281857 288851 300838 313826 316822 320818 
      326811 328806 330804 333796 337785 343778 350772 355764 
      357757 358747 362737 
 0.25 523261 519249 514239 504220 500214 496211 485208 481209 
      476212 474216 472220 471223 468226 465229 458235 454238 
      451243 446252 444258 443266 444270 448274 454275 458274 
      465269 474264 475264 473269 470277 470281 471284 480283 
      490281 492280 498282 503284 509284 516284 
 0.25 531204 531199 529191 526187 523183 519177 516174 510170 
      507170 504173 502178 504183 509187 511190 516195 519199 
      522202 527205 531204 
 0.25 471801 471794 469788 464782 457777 452775 449775 445778 
      443785 444791 447795 451799 458804 463810 467814 470806 
      471801 
 0.25 466835 464829 461824 452826 447836 444847 442854 436856 
      429862 421869 417876 414890 414901 414914 415919 419921 
      429924 436927 441929 445924 447913 448886 449881 451876 
      459869 464858 466849 466835 
 0.25 343752 338749 335747 331747 326749 318753 314759 310764 
      310767 313771 317773 323773 328770 333764 338758 340753 
      343752 
 0.25 326800 326796 324793 320793 317794 311797 309796 310792 
      309788 308784 305781 297778 292776 287776 276777 265780 
      259786 253796 248805 245815 245820 245826 247834 251839 
      254841 260842 267840 273836 282830 289822 294819 296819 
      298822 303824 306821 309817 315813 320810 324806 326800 
 0.50 522268 520260 519255 516248 506230 500220 493215 483212 
      480213 477216 475220 476224 473227 468231 463234 461238 
      456244 451254 451260 453264 458266 462264 469260 477258 
      479262 478270 481276 490276 498278 502279 508279 517277 
 0.50 521192 520190 520187 518183 517181 515179 512178 510179 
      512182 514185 515186 517187 520191 521192 
 0.50 435874 431874 429877 426881 423886 422890 423898 424906 
      423910 426912 432910 437906 438902 436894 434886 435878 
      435874 
 0.50 299791 295789 293786 291784 284784 277787 268789 261793 
      257798 254804 251815 251822 252830 256835 261836 265836 
      269834 274831 279826 282822 291811 295805 298799 299791 
 1.00 518268 518264 517260 516255 512246 507236 501228 496222 
      492220 487218 482218 486221 491229 492234 492238 491240 
      484241 477234 473233 468235 465237 461246 458253 460256 
      462256 467252 476249 480249 483254 486264 489269 494272 
      499273 504272 512271 515270 518268 
 1.00 289803 288799 284799 280796 275796 272798 268802 264809 
      261814 259820 258823 259828 265830 272827 277822 281816 
      284811 286807 289803 
 1.50 515262 512252 508245 505239 500232 496231 496236 498244 
      502252 500256 499256 495247 491245 487246 486250 486253 
      487256 492265 496268 501266 503264 507265 513266 515262 
 1.50 480239 479237 476236 473237 469239 468240 469242 472243 
      475243 477243 478243 480239 
 1.50 283805 280805 277805 274806 272808 270810 268814 268815 
      267817 266818 267819 270820 270821 272819 273818 275816 
      276814 277814 279811 281809 281808 283805 
 2.00 512261 512256 511256 509251 508249 507249 506249 505253 
      506255 506258 508261 511262 512261 
 2.00 495259 494254 494253 492249 488251 488252 490257 490258 
      493260 495259  
 
24HR QP VT 27/12Z
 0.01 484640 482634 479628 473623 468619 460617 454618 451621 
      449626 445631 437651 419683 413691 408699 406704 405709 
      402712 399713 394713 379719 363728 357732 351734 344740 
      340746 339750 338758 340762 342764 349765 364760 363766 
      362771 362775 366775 371771 380770 384771 386775 379780 
      370785 363791 362794 363797 366800 369803 367807 356820 
      352830 353837 356839 359840 361838 363835 364835 369837 
      373838 375840 375844 374848 375855 378862 379870 381874 
      392885 396892 402898 406901 410902 416903 423902 428901 
      433898 441891 447885 453880 456879 458883 460890 460897 
      461901 463904 468900 474890 475884 477878 477866 477861 
      478856 482849 488841 494832 497825 498819 499805 499797 
      497789 494773 488751 484743 478732 470723 468718 467714 
      467707 470696 475685 481664 483649 484640 
 0.01 529189 521157 506148 497146 492144 487144 484146 484151 
      482156 480158 475161 469168 463174 461176 459179 451180 
      441182 438187 438195 441205 442209 440211 432208 428203 
      423199 418201 413207 408209 401209 394211 393215 395218 
      396221 394225 390227 388235 389243 391249 397255 399258 
      396260 386269 382274 380281 385284 392287 399288 406285 
      417280 427274 432272 436273 440276 442278 441284 439289 
      437291 428309 427313 427319 430326 434331 438333 441332 
      452325 463317 469313 472308 474302 474297 474289 474278 
      474270 477266 483265 490262 493257 496250 499248 503250 
      507252 510251 510242 514233 512222 511213 512209 515206 
      519201 522196 527194 529189 
 0.01 477190 476185 474183 471182 468180 465183 461186 458190 
      455193 453197 454200 457202 460200 463201 466202 468201 
      469200 472199 473198 475194 477190 
 0.01 320055 319048 318044 312030 308022 304016 300012 293007 
      289006 286009 284012 281017 278020 268014 260009 255008 
      251009 248013 246016 246020 247024 249029 248036 248042 
      249049 251055 254060 260067 259076 261082 267089 273092 
      280093 286093 292092 305088 307085 310080 314068 318061 
      320055 
 0.01 268792 268787 265786 257789 250793 245797 244802 242809 
      241816 241822 243825 246826 251821 255816 259811 262804 
      266799 267794 268792 
 0.25 507183 509178 508172 505164 502160 496160 490162 483164 
      480170 481175 482179 484184 484191 481200 476205 470209 
      462212 457214 452218 449221 446222 436221 413231 408234 
      404239 403243 404247 410252 414256 416259 416264 419269 
      426265 437262 441263 445266 452270 457269 463266 474255 
      484247 486244 489239 491234 494233 497232 498229 500217 
      498205 500198 502193 507183 
 0.25 443705 442701 441700 439698 437698 434700 432702 431704 
      430706 429710 429711 428715 428717 428720 428724 431727 
      434726 435724 436721 438718 441717 444715 444713 444708 
      444707 443705 
 0.25 466839 464836 460834 453834 447834 439838 436840 435845 
      433850 431859 435863 442865 448865 453862 458854 462848 
      465844 466839 
 0.25 439770 435764 430758 425756 418754 412755 409757 406759 
      408764 411768 415774 420777 424783 433779 436777 440774 
      439770 
 0.25 394750 392747 390745 389745 387745 383744 380744 377745 
      375746 373749 372750 373754 375757 376758 377760 380761 
      381761 383761 386761 389760 391758 393754 394750 
 0.50 502177 502173 501171 499168 496169 491168 487168 485170 
      486175 490182 491189 489194 486201 467218 463217 457219 
      453223 447227 444228 437227 431229 426235 415234 413235 
      410239 411244 414246 420248 423249 423252 424256 428259 
      436259 439258 446258 455261 460260 465258 474251 478247 
      482242 489224 493222 495215 493194 498185 502177 
 0.50 452850 451846 450844 447844 444849 444853 446857 449856 
      450855 451853 452850 
 1.00 486219 487215 486211 482211 480213 476215 478221 475221 
      471224 468227 462229 455231 446235 443239 445245 446251 
      451251 455250 461252 468247 471244 476242 479240 481231 
      483223 486219 
 1.50 476238 477234 477229 477228 475229 474229 471230 470231 
      468235 469238 472238 475239 476238 
 
 
24HR QP VT 28/12Z
 0.01 504663 501655 497653 485653 474644 470644 468645 462652 
      452653 440651 434651 426656 419662 414668 407679 394679 
      391682 388687 387690 387696 389702 390712 386724 383731 
      379737 376741 368748 364750 360753 359755 361759 365762 
      370763 382765 393768 399772 401775 403778 402780 396784 
      391788 385792 380797 374802 370809 367816 367826 370827 
      374827 380824 387821 395815 398812 404813 409815 422822 
      431825 436827 444826 446823 444819 439814 434810 431804 
      431796 432790 434785 441781 446774 451767 457761 465756 
      475751 487742 494735 499729 503722 506713 508702 508692 
      507676 504663 
 0.01 540112 540108 538101 532093 528092 529084 532066 535050 
      534038 532027 529019 524005 520994 515983 509974 507973 
      505974 502980 500989 500995 498004 498013 497022 496031 
      495050 494055 491059 487068 483080 477091 474094 467096 
      455093 451090 444088 436090 433092 427100 423101 418100 
      410098 406098 401104 399108 397116 397124 400127 403125 
      409122 412119 416115 419112 422111 425111 429114 434116 
      437118 444128 433138 429152 429159 424157 422152 421148 
      418147 415148 414154 413158 413162 418165 420166 421170 
      416172 411185 405194 398201 397190 397181 403174 405170 
      406166 406163 401161 397163 393165 391164 385166 381170 
      378174 376180 375186 376191 381199 385207 389209 387217 
      386220 388222 392223 396222 401223 408223 412222 417216 
      417212 421206 427201 435196 440194 444193 451196 460190 
      464187 470184 476184 479187 486187 489189 490193 492196 
      495197 501197 512197 518196 523193 529184 531174 531167 
      534151 538132 540112 
 0.01 519274 520262 518253 513243 509231 504216 499207 493199 
      488196 481197 476198 473199 468205 464205 462203 459202 
      456205 452210 447212 444212 431216 417224 415229 415234 
      417238 421239 429240 436243 440260 444268 448275 450284 
      451293 454304 458313 467324 470325 474321 478311 480299 
      480290 480278 481271 482263 484263 485266 490274 495281 
      503289 509290 515286 
 0.01 354201 355196 353190 351184 347182 343182 340181 338177 
      335173 332170 328169 324168 321169 318171 318174 320177 
      326180 331183 334186 335190 338197 343202 351202 354201 
 0.01 315029 312023 308018 303013 297010 294007 290001 285994 
      282990 278986 278984 282983 288980 291977 290971 288963 
      284959 282960 279962 277968 273969 270968 266965 259966 
      252969 244975 238981 236987 238993 242997 242001 241004 
      239010 240017 245019 251017 256012 260011 268010 274013 
      277019 280023 286026 290021 293021 295023 304029 310032 
      315029 
 0.25 493689 491680 487675 476668 473666 468664 462663 456664 
      446667 434674 428678 425682 421689 415694 412695 406696 
      403696 400698 398706 399718 400727 404732 413738 424744 
      427753 426761 431766 435766 441761 445756 452751 458748 
      464743 475732 480727 485721 489713 491706 493697 493689 
 0.25 532121 533116 531112 531111 528110 528111 525116 525120 
      525122 528125 531124 532121 
 0.25 506249 506243 503238 500233 499228 496217 493213 490211 
      487209 482208 473210 458214 452216 448221 451225 450230 
      446241 448245 450248 454252 456257 463275 466278 469262 
      473250 483250 485250 489249 493248 495245 498246 500248 
      504250 506249 
 0.25 518063 519058 518054 517050 516049 514046 513049 511052 
      511054 511058 511063 511068 514070 516068 517066 518063 
 0.25 506155 507151 505148 500143 496139 492134 486130 481128 
      474126 472127 471132 472138 473144 471147 468146 464148 
      462148 460152 464157 466166 464169 462172 461178 462179 
      464177 466176 470172 475174 489178 492179 495178 498172 
      498166 496158 491153 494151 505155 506155 
 0.25 444109 444107 441104 438106 437108 438109 441111 444111 
      444109 
 0.50 486695 485688 481681 478677 474674 466671 456671 448673 
      443678 438683 429691 423697 404705 404714 406719 410723 
      424736 431737 436740 439743 442745 447746 456744 461740 
      464736 473726 479717 484706 486695 
 0.50 488219 485213 479212 470214 464215 458217 455220 455227 
      456236 456241 459245 465248 471246 475242 473234 473231 
      474227 480221 487220 488219 
 1.00 478696 475692 471691 467691 463689 458688 453688 445694 
      438700 434705 432708 433712 436718 437722 439725 447736 
      452734 456729 461717 468710 474704 477701 478696 
 1.00 468222 466221 463221 466223 468222 
 1.50 460696 459696 456696 453697 450698 450699 450704 453705 
      455705 456704 458703 458702 460697 460696