QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
506 AM EST MON FEB 13 2012
 
 
FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 13/1200 UTC THRU FEB 16/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 
 
UPDATE...

NO SIGNIFICANT CHANGES MADE TO THE PRELIM DAY 1 QPF FOR THE FINAL
ISSUANCE.

...DAY 1...

MID TO LOWER MS VALLEY/CNTRL GULF COAST...

HT FALLS PUSHING EWD FROM THE LEE OF THE CNTRL TO SRN ROCKIES AND
INTO THE CNTRL TO SRN PLAINS WL CONT TO SUPPORT A BROAD REGION OF
ISENTROPIC LIFT ON THE WRN SIDE OF THE EWD MOVG SFC HIGH PUSHING
ACRS THE SERN US AND OFFSHORE DAY 1.  THIS WILL RESULT IN A LARGE
REGION OF MDT PCPN AMTS EXTENDING THRU THE MIDDLE TO LOWER MS
VALLEY AND CNTRL GULF COASTAL REGIONS DAY 1.  STRENGTHENING LOW
LEVEL SLY FLOW OFF THE GULF OF MEXICO MAY SUPPORT A CONVECTIVE MAX
IN PCPN MOVG ALONG THE GULF COAST FROM THE CNTRL TO UPR TX COAST
EWD INTO THE FL PANHANDLE REGION.  THE HI RES ARW WAS FOLLOWED
MORE CLOSELY HERE FOR QPF DETAILS...WHICH WERE ALSO SIMILAR TO THE
IN HOUSE PSEUDO BIAS CORRECTED ENSEMBLE MEAN.  TO THE NORTH OF THE
COASTAL CONVECTIVE MAX...LIGHTER PCPN AMTS EXPECTED.  COLD TEMPS
IN PLACE WL SUPPORT ACCUMULATING ICE ACRS PORTIONS OF THE LOWER MS
VALLEY FROM AR/NRN MS INTO SRN MO...WITH ACCUMULATING SNOWS TO THE
NORTH OF THIS INTO THE MID MS VALLEY REGION.  SEE THE LATEST
QPFHSD FOR FURTHER WINTER WEATHER DETAILS WITH THIS SYSTEM.

CA INTO THE GTBASIN...

GOOD MODEL AGREEMENT WITH THE NEXT AREA OF NERN PAC HT FALLS
EXPECTED TO AMPLIFY INTO A CLOSED LOW OVR NRN CA EARLY DAY 1 AND
THEN PRESS SEWD THRU CA MON AND TOWARD THE SWRN U.S. BY EARLY TUE.
 PCPN DISTRIBUTIONS AMONG THE LATEST OPERATIONAL GUIDANCE ARE
FAIRLY SIMILAR ALSO WITH MDT TO LOCALLY HVY PCPN AMTS EXPECTED IN
THE WELL DEFINED COMMA HEAD/DEFORMATION PCPN BAND AFFECTING AREAS
FROM THE NRN TO CNTRL SIERRA..EWD THRU CNTRL NV/SWRN UT INTO NWRN
AZ.  AREAL AVG .25-.50"+ AMTS DEPICTED DAY 1 ACRS THESE
AREAS...WITH HEAVY SNOWS LIKELY IN THIS AXIS.  SEE THE LATEST
QPFHSD FOR FURTHER WINTER WEATHER DETAILS WITH THIS SYSTEM.

LEE OF LAKE ONTARIO...

LAKE EFFECT SNOWS OFF OF LAKE ONTARIO SHOULD BEGIN TO DIMINISH
EARLY DAY 1 AS INCREASINGLY ANTICYCLONIC LOW TO MID LEVEL FLOW
BUILDS ACRS THE ERN GTLKS.

 
 
DAYS 2 AND 3...

...MID TO LWR MS VLY TO OH/TN VLYS AND SOUTH/SOUTHEAST ON DAY 2...

A SRN STREAM UPPER TROUGH MAKING ITS WAY EAST ACROSS CO EARLY
MONDAY MORNING BE FLATTENING AS IT MOVES INTO THE OH/TN VALLEYS
EARLY ON DAY 2.  THE AREA OF MOST ACTIVE PCPN SHOULD BE ALONG THE
GULF COAST AHEAD OF A COLD FRONT WHICH SHOULD BE MOVING EASTWARD
IN ASSOCIATION WITH THE TROF.  LIGHTER AMOUNTS OF PCPN ARE
INDICATED BY THE MODELS EXTENDING UP INTO THE SOUTHERN/ERN GREAT
LAKES.  OVERALL HPC MANUAL QPF CONTINUED TO FOLLOW A BLEND OF THE
GFS/ECMWF AND INTERNAL PSEUDO BIAS CORRECTED GUIDANCE.  STILL HAVE
ENOUGH CONFIDENCE TO KEEP AN AREA OF HALF AN INCH TO ONE INCH
AREAL AVERAGE RAINFALL FROM EXTREME SOUTHERN AL AND THE WRN FL
PANHANDLE INTO WRN GA DUE WHICH ROUGHLY CORRESPONDS TO THE AXIS OF
HIGHEST PW VALUES AND STRENGTHENING H85 FLOW.  

...PLAINS TO SOUTHERN GREAT LAKES/OH AND TN VALLEY ON DAY 3...

ANOTHER WAVE KICKING OUT OF THE ROCKIES AROUND 15/12Z IS EXPECTED
TO AMPLIFY AS IT MAKES ITS WAY NORTHEAST.  BACKING FLOW ALOFT
SHOULD ONCE AGAIN GET GULF MOISTURE MOVING NORTHWARD IN ADVANCE OF
A DEVELOPING COLD FRONT.  HIGHEST AMOUNTS AGAIN SHOULD BE CONFINED
THE THE SOUTHERN MOST TIER OR TWO OF STATES ALONG THE GULF
COAST...BUT GOOD MOISTURE TRANSPORT AND MOISTURE FLUX CONVERGENCE
SHOULD ALLOW FOR PCPN TO MAKE ITS WAY AS FAR NORTH AS THE SOUTHERN
GREAT LAKES BY 16/12Z.  THE 15/12Z ECMWF WAS INDICATING THAT THERE
SHOULD BE A FAIRLY WELL DEFINED PCPN MAX IN THE COLD AIR ACROSS
THE UPPER MIDWEST...BUT THE 16/00Z ECMWF CAME IN MUCH MORE LIKE
THE 16/00Z GFS.  THE GFS ALSO HAD BETTER SUPPORT FROM THE IN HOUSE
PSEUDO BIAS CORRECTED VALUE.  DID NOT GIVE MUCH WEIGHT TO THE NAM
WHICH APPEARED TO BE TOO SLOW COMING OUT OF THE MOUNTAINS...AND
THIS SLOWNESS CONTINUES AS IT MOVES DOWNSTREAM. 
   
...WEST COAST STATES INTO THE DESERT SOUTHWEST/FOUR CORNERS
REGION...

THE SYSTEM THAT KICKS OUT ONTO THE PLAINS BY THE END OF DAY 2
BEGINS AS A BROAD AND COMPLEX UPPER TROF/SFC LOW EARLY ON DAY TWO
ACROSS THE GREAT BASIN.  PCPN IN THE AREA BECOMES BETTER ORGANIZED
JUST BEFORE THE SYSTEM KICKS OUT ONTO THE PLAINS...AIDED IN PART
BY THE SPEED MAX OF AN H25 JET SHIFTING TO THE EAST SIDE OF THE
UPPER TROF. 

BY LATE DAY 2/EARLY DAY 3...ANOTHER TROF DROPPING SOUTH ALONG THE
WEST COAST IS FORECAST BY THE GFS/ECMWF TO DEVELOP INTO A CLOSED
MID LEVEL LOW WHICH DROPS SOUTH INTO CA.  THE GFS/ECMWF WERE MORE
AGGRESSIVE WITH THE PCPN ASSOCIATED WITH THE SYSTEM.  WE TENDED TO
FOLLOW THE QPF FIELDS FROM THOSE MODELS BUT SCALED BACK PCPN A BIT
GIVEN THE LACK OF DEEP MOISTURE FOR THE SYSTEM TO WORK WITH.  

ORAVEC/BANN

GRAPHICS AVAILABLE ON THE WEB AT WWW.HPC.NCEP.NOAA.GOV
 
24HR QP VT 14/12Z
 0.01 533190 534175 531171 529166 526157 523152 520148 514142 
      511138 510133 505123 503114 499105 494099 488099 482105 
      479106 476104 473103 470103 465105 461102 455097 450095 
      444094 435095 429093 427095 428098 426102 425109 422118 
      422124 426125 431119 435118 440120 446124 452190 458185 
      464180 465178 463174 460172 459169 460166 464168 466171 
      469172 471171 475169 477167 481167 489169 499172 504179 
      505183 503186 501188 496194 493198 489201 482201 473204 
      465208 458211 455211 451209 446203 440196 433180 428172 
      423166 420164 415163 411163 410158 411150 409146 406140 
      413107 410098 409096 406096 405101 402104 396104 394101 
      394095 399089 404084 411080 413078 415072 415068 417063 
      422062 425060 427054 429047 427040 424037 416036 413038 
      412043 410050 406052 401051 387057 382059 377059 370057 
      366057 362059 356064 355070 358078 364078 367080 367086 
      367093 365096 369102 372109 371110 369105 366108 360112 
      354109 348103 345101 340099 335102 333104 345133 348142 
      354145 357145 362146 364148 364153 362162 357172 356177 
      353176 349172 341158 332159 326157 320158 317160 314165 
      314171 315174 320180 332193 336199 339208 341215 347219 
      353223 362224 366221 367215 365212 354201 354195 357194 
      363197 374207 382211 385215 389216 395222 396224 394226 
      383225 381228 381233 386241 394245 402250 409254 416255 
      421256 426255 433253 438250 441245 443240 442232 449227 
      453226 458226 466225 475221 484223 490220 496217 503212 
      506211 513210 521206 525203 528199 533190 
 0.01 518273 519267 517261 514260 512256 509251 502258 495249 
      485252 480262 478266 479270 481276 483280 486283 490289 
      497290 505291 509288 513282 518273 
 0.01 458707 456706 454709 452711 449712 446712 445712 443713 
      440716 439721 439722 440725 442728 444731 446732 449732 
      451728 451726 452721 453721 454717 456714 456713 458710 
      458707 
 0.01 445744 443743 440743 439743 437743 434743 432746 430749 
      431753 432756 432757 433760 433761 435764 438766 441769 
      442769 443768 443763 443762 443758 444754 444753 445748 
      445744 
 0.01 459834 457832 454831 449833 443834 435835 428834 421828 
      416822 411815 404809 396806 391810 390814 387824 384831 
      380834 374835 366834 361831 354828 345828 336828 320834 
      309839 303846 300852 294859 291866 288873 286880 282888 
      280895 273910 270916 264923 255933 253937 253940 254945 
      250952 249956 251962 255966 262969 266970 267974 270980 
      273985 276988 282992 288994 294995 299994 312986 314983 
      319982 329981 340979 344977 347975 364966 371963 378959 
      388957 395956 401957 403959 408967 411972 414975 420980 
      422985 422992 420003 420010 425011 428008 431004 437999 
      441991 444984 444980 445973 445966 443952 444940 443916 
      443908 441901 440894 440889 443878 446869 452860 455852 
      459842 459834 
 0.25 433940 433938 431936 430934 427937 428941 429945 431947 
      433944 434943 433940 
 0.25 399212 397207 394205 389200 384196 379192 374187 370185 
      366186 365189 370195 375200 380205 386208 393212 399212 
 0.25 401185 399179 399170 399164 400155 398146 395142 390142 
      387141 382130 378125 373126 369131 368135 368140 374143 
      376144 377148 376162 379170 384174 388177 395178 397184 
      401185 
 0.25 387917 387913 385910 382907 378907 376909 372906 370902 
      365897 357892 351886 346863 341854 336847 333845 327846 
      317852 309856 302862 298869 294877 287894 281909 278919 
      281923 284924 285928 283934 282937 280941 274948 273951 
      273957 273964 280970 287974 296975 307972 312971 315967 
      318960 322958 328957 339955 344952 347949 359937 363934 
      367932 371932 376930 382924 386919 387917 
 0.50 390172 392169 393165 393161 392157 392154 392153 389152 
      386153 383156 384160 384164 385165 386167 387170 389172 
      390172 390172 
 0.50 386201 384200 381198 380196 378195 376194 374191 373190 
      370190 373192 374194 375196 378199 380201 383202 386201 
 0.50 349905 349901 348900 346899 344897 342896 341896 338895 
      335895 334899 334902 335905 338907 339908 341909 344908 
      346907 349905 349905 
 0.50 311872 311868 308867 305867 303869 298879 293886 290895 
      286905 284909 284915 289916 290917 291921 290933 285941 
      282945 280950 279954 279961 283965 288967 297968 301966 
      304962 305955 304948 307939 309927 308920 306913 309904 
      311899 310892 309879 311872 
 1.00 294954 291953 289953 287955 289956 292955 294954 294954  
 
24HR QP VT 15/12Z
 0.01 509255 510248 510244 508235 503227 498219 483205 474206 
      467206 462208 458207 453209 448205 445200 441193 436190 
      431188 424187 420190 418189 415184 411182 407183 402189 
      396192 389191 389186 392184 396176 400173 402167 402163 
      405159 410156 416157 419158 421156 421150 418147 415146 
      410147 406145 404139 404135 408129 412119 414113 414105 
      411095 413087 417079 418077 421078 422082 421094 419104 
      420109 423112 426115 427118 431121 434120 441121 443125 
      443131 445137 444141 436140 433151 434158 436162 445178 
      447188 449192 452194 463184 467181 471183 474188 479188 
      486187 488184 489180 487171 486166 482161 475162 471158 
      469153 470146 473145 477146 480149 485150 490150 492149 
      494146 491140 489137 487130 488123 490119 496117 501113 
      502110 504105 503097 501086 496078 491072 484068 480068 
      476072 474074 471074 467072 459067 457064 458061 460057 
      462053 464047 466040 466032 464029 460026 452024 446027 
      441029 439032 436041 436048 434051 432055 429056 425057 
      419062 414062 409061 406059 400060 391063 384065 383062 
      383057 385054 385046 380043 377042 372047 364051 335048 
      329048 324047 320047 316049 314053 313058 314063 315069 
      314075 309081 299081 292085 290088 291094 297099 309108 
      311112 310117 308124 307129 307134 308136 312139 316140 
      321140 327135 333132 337133 339136 341144 343148 348150 
      350151 354149 358145 360142 361135 363134 366136 370143 
      375147 376148 377151 374156 371158 364157 358157 354164 
      353166 353169 355173 358174 364175 369177 374183 376188 
      373191 371190 368190 365193 364197 366203 369205 376210 
      381216 385219 388221 394226 401235 398246 399250 402253 
      406255 411256 417256 428257 437259 451260 455262 459266 
      464273 477292 480296 484299 487301 491300 494297 496289 
      495281 493272 503266 508259 509255 
 0.01 389643 380651 367661 352672 340681 324693 318699 317705 
      316719 316726 314734 311743 309756 301780 289834 286843 
      280855 278861 274866 267874 265901 259927 254946 251958 
      252965 255966 258965 262963 264960 269955 277945 290926 
      302907 310898 314893 319889 324884 331879 337876 343875 
      357877 364877 370879 382879 389876 393873 402862 407856 
      409849 415844 419843 419845 423863 424867 428871 431872 
      435871 447862 454852 458845 459838 459830 458826 456826 
      443835 442837 440835 437829 436822 437818 438812 442809 
      448809 453808 456805 460798 462791 463782 464768 460756 
      457754 453755 447755 436753 429752 423752 417750 410751 
      407755 406759 406764 404768 399773 392778 378783 369794 
      363799 360805 356810 353805 352800 349796 344794 340790 
      339786 341782 345769 353756 359746 367734 382712 388705 
      390696 391689 395682 405667 408660 412655 414648 412639 
      408633 401633 
 0.01 409003 409990 408982 407975 403962 400957 397955 381948 
      373943 366937 360933 352930 340932 328935 319939 311944 
      305950 300958 297965 296974 298985 301990 304992 308994 
      310996 307002 302004 300008 298015 298021 299026 299032 
      301038 303040 306042 309041 312038 315035 318029 320022 
      325015 339003 345997 348994 349989 351984 354983 357983 
      359982 362983 366986 372989 378996 382006 385011 388013 
      394016 398017 402015 407008 409003 
 0.01 336177 337170 336165 333163 328159 326156 322154 318152 
      313153 312156 313160 316163 319167 321171 324173 326175 
      332178 336177 
 0.25 469218 467216 464216 462216 461217 457218 456219 457221 
      459224 459225 461224 463224 465221 466221 469218 
 0.25 379664 376662 369666 355676 349680 343686 339690 335696 
      335710 332724 332730 330736 325747 322753 320759 317772 
      316778 316784 318786 321786 325781 333771 340761 344755 
      347749 352737 359727 364720 366715 370708 374703 378697 
      380689 381676 379664 
 0.25 387090 387083 386079 383076 378073 375072 369072 367073 
      364075 366079 368082 370086 373090 374097 378101 383097 
      386094 387090 
 0.25 348845 348838 346832 343828 339825 332820 329819 323820 
      316826 311834 306841 298847 289862 287870 285879 285888 
      285895 288899 293899 298896 306890 311885 317877 322871 
      329864 345853 348845 
 0.25 352124 352119 350117 346111 346103 345098 344093 340089 
      333086 329087 327092 326098 328105 332112 336116 340120 
      345124 349125 352124 
 0.50 369676 366672 363672 353679 350687 348691 349694 348696 
      347700 342705 340708 339713 339719 340723 345718 350709 
      354703 358697 361694 367686 369680 369676 
 0.50 343843 339836 335831 329830 323833 318838 312843 302851 
      294863 292867 290875 291883 293888 294890 300888 307883 
      316873 323864 327859 335855 340851 343843 
 
 
24HR QP VT 16/12Z
 0.01 514281 517272 519263 518249 517239 515234 507227 501224 
      495223 486225 482230 479232 472237 463242 456245 451247 
      447247 441247 438249 434251 431257 430261 432265 437267 
      444269 449269 460275 466279 477280 484282 489285 500290 
      505291 509289 512285 514281 
 0.01 468747 466744 462742 458740 455737 451737 445738 440739 
      436742 432748 427756 425764 421780 421789 422794 426799 
      428800 432798 436791 437783 437773 441772 444775 449780 
      451781 455779 458772 460764 464758 468751 468747 
 0.01 461886 459879 458870 454850 451837 444823 436811 432807 
      427804 418801 410796 400791 395790 389789 380789 372790 
      368792 361793 354795 345797 336804 331809 329813 325825 
      323831 320837 314843 305852 299859 292868 282884 270905 
      266914 263923 263933 264939 266944 270948 274951 279953 
      278958 273967 273971 275976 277981 279986 282989 291993 
      298994 304994 312997 317997 322995 327992 332988 339982 
      345979 353977 362979 368979 372983 375989 376996 379007 
      376018 372024 368028 361029 357031 354036 355040 357043 
      364051 369054 372055 372060 369067 365079 380094 383094 
      389090 398082 404074 405071 404068 402060 404053 403049 
      401046 396042 391039 391031 397020 398013 402010 407007 
      411011 416022 421033 427044 434053 437055 441052 443047 
      448035 448029 447025 446019 443009 443004 444990 447982 
      452977 455973 457967 457961 456956 454951 451946 450941 
      450937 453926 459904 461894 461886 
 0.01 363672 362668 358668 353671 340679 333685 330690 326695 
      324701 320713 316724 309735 306739 303746 302752 302759 
      304772 307781 310786 315789 318788 320785 328763 340738 
      345727 352715 354710 358704 362691 363680 363672 
 0.01 421182 423174 423165 423160 421154 416148 412145 407141 
      390132 387124 385119 383117 380117 375119 371123 367130 
      365135 362136 359135 356135 353138 348141 343141 338140 
      322132 313130 307134 301141 296148 293151 292155 291160 
      292164 294168 296170 304175 310183 317189 326192 328192 
      330189 334186 339188 342196 345203 350205 354205 363199 
      368198 373200 377206 380210 384215 393221 399220 402217 
      404197 414187 419185 421182 
 0.25 444871 442860 438848 437843 433837 427836 422836 414838 
      408837 403836 396837 390837 386834 380818 377812 373808 
      369808 366809 358815 347821 342825 338828 331838 323850 
      316859 302876 295886 290895 287900 285906 283917 283924 
      284928 287929 291932 293938 292943 293952 298960 307970 
      313971 317970 321968 327965 337956 346948 357943 365941 
      369941 371943 377955 382958 388960 400963 404963 409960 
      413954 415948 422935 426922 428915 432908 436898 440889 
      442882 444871 
 0.25 383903 381900 380899 379900 377902 377904 378907 381906 
      383903 
 0.25 348168 348165 348164 346161 345160 343157 340157 339157 
      337158 335160 334163 335166 336168 339169 341170 344170 
      347169 348168 
 0.25 324161 323159 322158 320156 317156 315155 312156 313160 
      314161 316164 319165 321164 322164 324161 
 0.50 425881 425875 423870 420869 416872 413878 411886 410903 
      408913 403916 399920 395921 389923 385929 380937 382943 
      384945 390948 395948 399946 404942 407939 409934 410926 
      411917 412914 414911 421896 423890 425881 
 0.50 371832 371825 368821 364822 362825 359833 355839 351840 
      347838 344837 339839 330851 321865 317870 314877 315883 
      319885 322885 323888 320894 314901 309907 305908 301911 
      298916 296919 298921 302923 302930 302937 300945 301950 
      303953 307955 309958 313960 318959 325955 331951 343939 
      349934 353929 358920 360912 356889 355878 355872 357869 
      366856 369850 371843 371832 
 1.00 350908 349904 345901 338896 333897 328900 323906 319915 
      317923 318936 322939 326938 333933 338927 344920 349912 
      350908