Quantitative Precipitation Forecast
Issued by NWS

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114
FXUS04 KWBC 060934
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
432 AM EST SAT FEB 06 2016


FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID FEB 06/1200 UTC THRU FEB 09/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


...SOUTHEAST STATES...

AN IMPRESSIVE MID WINTER SHORTWAVE DIGS TO A LOW LATITUDE...WITH
500 MB HEIGHT ANOMALIES DOWN TO -2.5 STANDARD DEVIATIONS OVER
FLORIDA BY SUNDAY MORNING. CYCLOGENESIS OFFSHORE OF
FL/GA/SC...ALONG WITH AN INCREASINGLY DEEP UPPER SYSTEM WILL LEAD
TO STRONG ASCENT AND AN INFLUX OF MOISTURE...PRODUCING AN
ORGANIZED PRECIPITATION EVENT ACROSS THIS AREA. MODEL AGREEMENT IS
FAIRLY GOOD THROUGH EARLY DAY 2...AND THE QPF INHERITED FROM THE
PREVIOUS SHIFT PROVIDED A GOOD STARTING POINT. WE INCORPORATED
WHAT LITTLE TREND WAS OBSERVED TO THE QPF CONSENSUS ON THE 18-00Z
CYCLES...MAINLY A WESTWARD EXPANSION OF EACH ISOHYET BY ABOUT 30
MILES...CATCHING MORE OF SE GA WITH 0.10 TO 0.50 INCH AREAL
AVERAGE FOR THE 24-HOUR PERIOD. THE 00Z NAM DID APPEAR TO BE TOO
STRONG WITH THE SYSTEM AT AN EARLIER LEAD TIME...WHICH CAUSED ITS
DAY ONE OUTPUT TO PRODUCE MUCH MORE PRECIPITATION OVER SE GA INTO
COASTAL SC. WHILE THIS REGION SHOULD SEE THE MAXIMUM PRECIPITATION
AMOUNTS...GIVEN THEIR PLACEMENT IN THE DIFLUENT REGION NORTHEAST
OF THE UPPER LOW...THE MANUAL FORECAST IS MORE CONSERVATIVE THAN
THE NAM...BEING MORE IN LINE WITH THE GLOBAL CONSENSUS...THE
CANADIAN GEM REGIONAL MODEL...AND THE NAM CONUS NEST.

MEANWHILE...DOWN ACROSS SOUTH FLORIDA A REMNANT FRONTAL SYSTEM
WILL LIFT NORTHWARD FROM CUBA...BUT IS LIKELY TO REMAIN JUST
OUTSIDE OF THE STATE BEFORE LOW PRESSURE FORMS OFF THE SOUTHEAST
FL COAST AND LIFTS UP TOWARD THE CAROLINAS. AT THE SAME
TIME...HOWEVER...A SHARPLY DEFINED SURFACE TROUGH SHOULD FORM FROM
WEST OF NAPLES...CUTTING ACROSS SOUTH FLORIDA IN RESPONSE TO THE
INTENSE UPSTREAM HEIGHT FALLS. STEEPENING OF LAPSE RATES AND
STRONG SURFACE CONVERGENCE SHOULD BE SUFFICIENT TO FORM
THUNDERSTORMS DESPITE THE AREA BEING NORTH OF THE SYNOPTIC FRONT.
SOME SOLUTIONS SEEMED OVERDONE FOR MAGNITUDES GIVEN THE EVENT WILL
BE QUICKLY EVOLVING...BUT THERE WAS GOOD SPATIAL AGREEMENT TO THE
QPF FROM THE ECMWF...WRF-NMM...AND NAM CONUS NEST. THESE WERE
BLENDED WITH THE PREVIOUS WPC FORECAST TO MAINTAIN CONTINUITY.


...NORTHERN U.S. FROM MONTANA TO NORTHERN  NEW ENGLAND...

A SHARPLY DEFINED NORTHERN STREAM WAVE WILL DEEPEN AS IT ENTERS
THE NORTHERN PLAINS...WHERE HIGH WIND AND BLIZZARD WATCHES WERE IN
EFFECT. A DOWNSTREAM TROUGH WILL ALSO GRAZE THE GREAT LAKES AND
NORTHERN NEW ENGLAND. BOTH WEATHER SYSTEMS ARE WORKING WITH
RELATIVELY DRY AIR...BUT THERE IS AGREEABLE MODEL SIGNAL FOR AREAL
AVERAGE 0.10 INCH LIQUID FROM NORTHERN ND ACROSS NORTHERN MI TO
NORTHERN NY AND MAINE. THE SYSTEM ENTERING NORTH DAKOTA IS
PARTICULARLY DYNAMIC...SUCH THAT IT MAY SQUEEZE OUT AMOUNTS
GREATER THAN A QUARTER INCH THROUGH SUNDAY MORNING UP AROUND
BOTTINEAU AND NORTH OF DEVILS LAKE. THE PREVIOUS WPC FORECAST
PROVIDED A GOOD STARTING POINT...AND WE INCORPORATED SOME ASPECTS
OF THE GFS/ECMWF AND 18Z GEFS MEAN TO DEFINE THE SOUTHERN EXTENT
OF MEASURABLE PRECIPITATION AND EACH CATEGORY UP TO 0.25 INCH
AREAL AVERAGE. THE 00Z GEM REGIONAL AND SOME OF OUR IN-HOUSE
DOWNSCALED QPF TECHNIQUES WERE ALSO HELPFUL...AND LINED UP SUCH AS
TO INCREASE OUR CONFIDENCE.


...NORTHWEST / NORTHERN ROCKIES...

THE SHARP WAVE PASSING TOWARD THE NORTHERN PLAINS WILL PUSH A COLD
FRONT THROUGH THE NORTHWEST STATES AND NORTHERN ROCKIES. MOISTURE
IS IN LIMITED SUPPLY...BUT STRONG WESTERLY TO NORTHWESTERLY FLOW
WILL PAINT THE HIGHER TERRAIN WITH LIGHT ACCUMULATING
PRECIPITATION. MODEL FORECASTS AND OBSERVED PRECIP ASSOCIATED WITH
ANALOG EVENTS FROM THE GEFS REFORECAST DATABASE ARE WELL ALIGNED.
WE STARTED WITH THE PREVIOUS FORECAST AND MADE MINIMAL
CHANGES...INCORPORATING THE GEM REGIONAL AND NDFD FOR SOME OF THE
DETAILS.


...SOUTHERN PLAINS TOWARD THE WESTERN TO CENTRAL GULF COAST...

A STRONG MID LEVEL TROUGH CONTINUED TO DEEPEN AND DEVELOP TOWARD
HAVING A CLOSED CIRCULATION PER SATELLITE IMAGERY. THE SYSTEM WAS
SURROUNDED BY SUCH DRY AIR...HOWEVER...THAT WIDESPREAD RADAR
ECHOES APPARENTLY REPRESENTED MAINLY VIRGA...ALTHOUGH A FEW SITES
IN OK/TX HAD REGISTERED MEASURABLE PRECIPITATION AS OF 09Z. MODELS
CONTINUE TO AGREE THAT THE BEST LIKELIHOOD FOR ANY SIGNIFICANT
RAINFALL WOULD BE JUST EAST AND NORTHEAST OF THE TRACK OF THE MID
LEVEL LOW...ACROSS EASTERN TX. A SECOND SWATH OF PRECIPITATION
WILL FORM OFFSHORE IN THE GULF...WHILE MOST AREAS INLAND ACROSS
SOUTHEAST AND CENTRAL TEXAS SHOULD SEE ONLY A FEW HUNDREDTHS OF AN
INCH AS THE TROUGH PASSES QUICKLY THROUGH THE REGION EARLY TODAY.


DAYS 2/3...

...GREAT LAKES TO OH-TN VALLEYS/APPALACHIANS...

WIDESPREAD BUT GENERALLY LOW VALUES OF LIQUID EQUIVALENT ARE
EXPECTED TO DEVELOP IN ADVANCE OF THE LONGWAVE TROUGH POSITION
SUNDAY NIGHT INTO MONDAY AS A UPPER TROUGH EVOLVES INTO A CLOSED
MID/UPPER LEVEL LOW OVER THE OH VALLEY. GIVEN THE COMPLEXITY OF
THE SMALLER-SCALE AND SUBTLE RUN-TO-RUN VARIABILITY OF SOLUTIONS
EMBEDDED WITHIN THE TROUGH...A MODEL CONSENSUS WAS USED TO DERIVE
THE QPF. SINCE SOME PRECIPITATION WILL ALSO FALL AS SNOW...REFER
TO THE LATEST GUIDANCE FROM THE WPC WINTER WEATHER DESK FOR MORE
INFORMATION.


EAST COAST...

THE 06/00Z MODEL RUNS BACKED AWAY FROM THE SLIGHT WESTWARD SHIFT
THAT THEY MADE DURING THE 05/12Z PRODUCTION CYCLE.  AT FIRST...THE
REACTION WAS NOT TO MAKE TOO MUCH OF A MOVE AWAY FROM THE 05/12Z
ECMWF AND THE 06/00Z NAM WHICH CLUSTERED WELL.  THE CORRESPONDING
RUNS OF THE GFS AND UKMET WERE NOT AS AMPLIFIED AS THE
ECMWF/NAM...CONSEQUENTLY THEY TENDED TO MOVE THE FIRST WAVE OUT TO
SEA MORE QUICKLY.  THE QUESTION HAS BEEN WHETHER A SECOND
SHORTWAVE DROPPING IN FROM THE GREAT LAKES WOULD BE FORCED TO TAKE
A SOUTHERN TRACK IN THE EVENT THE FIRST WAVE WAS BLOCKING ITS
FORWARD PROGRESSION OR WHETHER THE FIRST WAVE WOULD BE OUT OF THE
WAY IN TIME TO ALLOW MORE AMPLIFICATION OF THE SECOND WAVE.  SINCE
THE OVERNIGHT RUN OF THE GEFS MEAN WAS FAIRLY CONSISTENT WITH ITS
PREVIOUS RUN...WE OPTED NOT TO MAKE ANY TOO MANY CHANGES IN THE
WPC FORECAST.  WITH THE MODELS HAVING A RATHER DIFFICULT TIME IN
HANDLING THE WAY THE MASS FIELDS INTERACT...IT FOLLOWS THAT THE
CONFIDENCE IN THE RESULTING QPF WAS BELOW AVERAGE.

REFER TO THE QPFHSD FOR MORE INFORMATION ON ANY WINTER WEATHER
WITH THIS SYSTEM.

GRAPHICS AVAILABLE ON THE WEB AT WWW.WPC.NCEP.NOAA.GOV

BURKE/BANN


24HR QP VT 07/12Z
 0.01 532203 533193 532185 528172 525165 522160 519156 514152
      505145 494138 486129 482125 477124 474122 476115 474108
      470105 468103 466104 465110 462094 460089 458083 450073
      446068 442067 437068 432073 436078 442080 447083 451088
      455093 457097 457101 455100 452095 447094 440095 436095
      433092 429090 427088 426089 428092 429098 430102 428105
      426107 427108 430110 429115 432118 436114 442117 445121
      446123 449124 452119 456116 461114 463114 463119 462121
      463124 462128 460131 458134 458140 456146 455154 460157
      468164 481163 490172 493176 496183 505191 514198 524206
      529206 532203
 0.01 545987 539956 536947 533942 529936 514889 501860 495847
      492841 489833 489827 490823 493815 496803 498795 499786
      499777 496772 495765 498751 499741 495733 495714 497695
      502688 506672 501639 491626 483636 472657 459685 452698
      448712 447720 446726 435753 435761 434769 430781 425795
      423801 427798 440776 444771 447766 451760 453758 454760
      453764 447792 445799 442804 440811 441814 444817 451826
      451831 450834 450839 449843 440852 437858 437863 438866
      442866 444864 447864 447867 444874 444882 445890 448898
      452911 455917 458923 459925 462927 466931 465935 461941
      457947 457955 455962 458968 465979 467982 467987 468997
      468006 469014 477042 479049 481057 485073 490101 495115
      497118 500119 505114 508110 513098 514081 514063 516050
      525034 529030 532024 535019 540011 542003 545987
 0.01 516262 518249 517243 514238 505221 501212 495205 492203
      487201 481206 474209 465211 463213 458214 454218 459226
      467223 475221 484223 489225 492228 496237 498243 495245
      489239 485238 482241 478230 473234 472236 475242 480248
      485256 486262 484266 481269 477271 464278 460287 457302
      458307 461310 469315 477315 484311 490307 498302 503296
      507288 510282 512274 516262
 0.01 482095 482092 483090 481090 479092 481095 480097 482097
      482095
 0.01 452168 452166 450163 449160 448157 446155 445152 443149
      441149 439151 438153 437156 441157 442159 444162 445165
      448165 450168 452168
 0.01 429248 428241 423238 417237 412239 408241 405246 404252
      407256 413256 417254 422251 427249 429248
 0.01 446046 445043 445041 443038 441038 440040 441043 443045
      443046 444046 446046 446046
 0.01 440060 441055 438050 436045 434042 431040 429042 427046
      428051 432054 433057 436062 439062 440060
 0.01 426060 426058 425058 425060 426061 426060
 0.01 415076 415073 413070 412068 414066 415066 416062 414061
      412063 409063 407065 405065 401067 405070 406070 408075
      410075 413076 415076
 0.01 406058 405058 404056 402055 402056 404058 405058 406058
 0.01 358752 357739 356734 352731 344727 335725 327727 323729
      317730 313732 310735 303742 288752 273762 258773 253779
      248786 244794 242797 241803 239807 236811 233820 230826
      227834 227840 230840 239837 241842 244843 248843 252840
      256841 259846 262854 253868 250875 246885 245889 245895
      249901 252906 253914 254923 255934 257938 257945 260954
      265962 268964 274964 285964 294960 299954 303952 309952
      317955 334963 339963 342961 341954 340949 336940 332936
      329934 323930 314926 308920 301915 291901 289897 287891
      286885 285879 284868 281859 279854 279848 276843 273840
      266835 265831 269829 275828 280825 284824 287827 305830
      307833 311833 318826 327823 332822 336820 340818 345814
      350809 352800 355789 356779 358766 358758 358752
 0.01 457130 456132 455133 454132 454130 455130 456129 457130
 0.25 534000 534994 533987 528979 526976 523970 522966 522962
      523955 522948 518938 514929 512926 509925 508926 509929
      506929 507936 508942 510950 507948 504950 501949 497947
      497952 498957 502967 506975 511983 517990 522997 527005
      529006 532005 534000
 0.25 502278 503273 502270 498268 497276 494280 490284 485287
      481291 482295 485296 491297 495293 498288 501280 502278
 0.25 506006 505001 502994 499988 496982 492979 487981 485987
      485997 487003 491008 495010 501013 505012 506009 506006
 0.25 489142 489139 489138 488136 487135 486134 484136 485137
      486139 487140 488142 489142
 0.25 475845 473844 472843 471843 469843 469846 470847 471846
      473847 475845 475845
 0.25 350744 347743 342744 338746 334745 322743 319741 315742
      309747 304752 298757 275774 263784 253794 249800 245807
      239820 238825 240828 244827 247825 253821 261818 266813
      273810 280807 284805 289805 300813 308814 315816 319817
      323818 330814 336809 340803 344796 346788 345765 345759
      347754 350744
 0.25 328949 327947 327946 326945 325944 324943 323942 322941
      321941 319940 317939 316941 317943 317944 319945 321947
      322947 323948 325949 327950 328949
 0.25 282941 281932 279923 278914 275907 271900 269898 266897
      264900 263905 264913 267921 270929 272935 273940 276942
      280943 282941
 0.50 342755 334755 328759 316771 314773 309774 308772 309769
      310766 315759 315755 315749 313747 310749 305756 294766
      289771 282776 275780 269785 258795 251809 246815 245819
      248821 260812 266807 274803 284794 289792 292793 296794
      299798 300804 301808 306809 312807 317807 320810 324811
      328810 334804 338799 341790 339766 341759 342755
 0.50 270909 270908 269909 270909 270909
 1.00 332776 332770 329767 322772 316779 311784 304791 302793
      303797 304804 309804 316800 324795 329788 332778 332776
 1.50 327781 326777 323776 321778 319780 316784 313787 311790
      308794 308799 312799 315796 319793 321791 324788 327783
      327781
 2.00 315792 315791 315792 315792

24HR QP VT 08/12Z
 0.01 534193 533184 529178 520165 515158 511153 509150 505149
      499149 491146 489147 490152 492155 495157 498159 498163
      493167 491168 492171 498175 505177 509177 511179 515186
      524200 526202 530204 532201 534195 534193
 0.01 520258 520252 517247 514243 512239 509227 507224 503220
      497213 488210 485215 484222 485225 483226 479226 472234
      469243 474245 477246 478249 476255 473259 467266 463274
      465279 468283 472285 476289 481291 485290 489291 493290
      501286 508280 513273 515266 518261 520258
 0.01 528952 525930 525926 526923 526917 526900 522879 519865
      516853 512833 510827 510822 504811 495797 492793 489792
      484783 483780 481777 475771 461765 458763 453764 450767
      449773 449779 448785 442788 436793 426795 408802 394809
      389810 384813 377818 365827 362829 360832 355841 350848
      349852 349859 350864 352867 355870 358872 357880 357886
      360890 370889 377885 391877 403865 407866 409868 410871
      410873 406876 401884 397891 396897 396902 396915 398919
      398926 402933 411946 424958 429964 436968 449978 455983
      457985 460989 467994 470996 471999 471003 469008 468012
      469017 469021 474029 484030 492031 498028 502025 504021
      510014 513004 515994 522973 526961 528952
 0.01 507685 505669 503655 498643 492637 484635 479637 477641
      468661 463669 459679 455688 454700 453705 454714 453719
      454725 458727 464725 471718 476711 482703 485700 488699
      490700 493702 499701 505694 507685
 0.01 488136 487136 486133 484132 483132 481132 479131 478131
      476129 474128 473128 474131 476132 478132 479133 481133
      482133 484136 486136 487137 488136
 0.01 438859 438856 436855 434857 433857 431859 431860 429860
      428862 429864 431866 433866 434864 435863 436861 438859
 0.01 417693 416686 413680 409676 405674 400673 392676 381674
      371674 365673 357675 351677 347680 338687 330695 320702
      302716 292721 281727 274733 269737 265742 259749 252759
      248767 247772 249775 251776 257775 260774 262772 267769
      268767 272767 278768 283773 290779 293782 296788 299792
      305794 308797 315800 320802 325803 335804 342804 347801
      352798 355795 360783 361769 367759 370754 375752 386747
      395740 404732 410722 412717 414710 416701 417693
 0.25 511257 511250 508245 505244 503246 498247 493248 490252
      487259 485264 486268 489270 493269 497268 501264 506261
      509262 511260 511257
 0.25 493939 493933 492926 491914 491900 491886 489874 488869
      486864 481858 475854 473856 472861 472868 470873 466893
      463902 462905 461913 462924 466932 470941 474948 480952
      484952 487951 491945 493939
 0.25 474825 472816 469809 466806 462805 456806 449809 446811
      447817 452821 455822 458825 459828 462830 469833 473830
      474825
 0.25 402701 402696 400693 397690 392690 378685 372683 363682
      354686 348690 336701 325713 315725 311730 304736 296739
      289743 284748 285753 287757 296771 305782 310788 317792
      323795 332796 339795 344792 346789 349782 352773 355766
      360759 365753 372747 393725 397719 400714 402708 402701
 0.50 398709 398699 395697 392696 385696 377694 367689 359689
      351693 340702 331712 323722 314734 306744 303750 301757
      301762 302766 306772 310778 314783 319787 325790 333791
      341788 344782 347775 353762 357757 361751 366746 371742
      382733 387728 391723 395716 398709
 1.00 393711 391706 383707 379710 376710 374707 370704 364703
      353700 347703 343707 335714 327724 321733 315743 311755
      310762 313768 319778 324782 329784 335783 340779 351758
      357748 364740 368736 375734 380731 384726 390718 393711
 1.50 387717 386714 384714 379716 374719 370720 367719 359714
      351711 345712 341715 334721 328730 323739 319748 317760
      318766 320771 323774 326777 332778 335778 339775 343770
      352751 357742 359738 363733 367731 370730 373731 376730
      380727 385721 387717
 2.00 356732 356728 355724 350721 345720 340724 332732 326742
      324747 323754 321760 322764 324769 327772 332774 337773
      342768 347758 352746 355735 356732
 3.00 345752 345745 343741 338741 335743 332748 331752 330757
      328760 328766 331768 336768 340764 341762 344757 345752
      345752

24HR QP VT 09/12Z
 0.01 512037 511032 508027 505022 501020 495020 491017 488012
      485009 482004 478002 476001 473999 472999 470001 473011
      479019 486027 487033 491036 495038 500040 510040 512037
 0.01 504860 503842 502826 495815 493812 493807 492798 486786
      484781 481777 478772 475768 471764 467761 452750 446748
      442745 440742 441739 444735 447706 449700 453697 457694
      462689 464683 465678 463666 459648 457640 454634 450630
      446631 436634 425652 421657 415659 405663 399667 393670
      388673 384677 362688 356696 353699 347700 343699 341703
      334710 326719 319727 311735 304744 300747 298752 293761
      286780 283787 280792 277797 276802 276809 280812 290816
      298820 292828 286835 282839 283845 284853 287859 292870
      297880 301883 305885 309886 312884 323877 330872 337865
      340862 344864 348866 351872 354878 357883 361885 368885
      370885 372888 373906 375913 377916 378918 382918 386918
      389913 392911 396906 401901 411897 417896 421898 430906
      434910 438911 444914 448918 452920 455925 460932 462935
      466936 471937 480932 487922 490912 490894 495889 497883
      501870 504860
 0.01 361765 360760 358758 353758 350759 348762 343766 338771
      335776 329787 322799 321802 322805 326810 332813 337815
      341811 345805 356799 357797 355795 352795 351786 350782
      352780 357774 361765
 0.25 481864 473845 470835 469821 467810 461802 454797 446795
      430792 421790 412790 403791 397793 393796 388802 383803
      379805 374811 371815 366817 361825 360829 360832 365833
      368835 371838 375839 381840 385838 390831 392827 394825
      398822 402823 407824 410828 417832 423836 431838 443839
      450840 454840 458841 461845 462851 462878 464889 466895
      468898 472897 475893 478884 480873 481864
 0.25 451676 452668 451661 447655 443654 440654 437656 432659
      425664 416669 405675 394681 391684 387688 383697 379700
      375701 356706 348712 340720 333728 328736 317752 312762
      309766 305769 303773 302777 303785 306790 310790 314787
      321780 334765 347751 359735 365733 368729 379729 387732
      398733 404733 409730 416724 424718 428714 431710 437700
      443692 448684 451676
 0.50 442672 441668 439666 434667 431669 418675 405682 399686
      395690 391696 390703 389712 391717 394719 400718 406717
      413713 417709 423705 427700 436689 439683 441676 442672
 0.50 359720 359716 357714 350718 345721 340727 335732 331739
      328746 326753 322759 318765 314770 313774 314779 316779
      319776 323771 326764 327761 330759 337756 341750 350738
      358725 359720

$$





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