Quantitative Precipitation Forecast
Issued by NWS

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374
FXUS04 KWBC 070634
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
134 AM EST SUN FEB 07 2016


PRELIM DAY 1 QPF DISCUSSION
VALID FEB 07/1200 UTC THRU FEB 08/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...EASTERN SEABOARD...

LOW PRESSURE FORMING OFF THE SOUTHEAST COAST WILL INTENSIFY TO
NEAR 980 MB BY MONDAY MORNING...WITH THE UPSTREAM MID LEVEL TROUGH
DIPPING TO 3 STANDARD DEVIATIONS BELOW CLIMATOLOGY IN THE 500 MB
HEIGHT FIELD. A BAROCLINIC ZONE HAD PREVIOUSLY BEEN ESTABLISHED
OFFSHORE...WHICH WILL ENCOURAGE THE SYSTEM ALONG WITH A FAIRLY
PRONOUNCED EASTWARD COMPONENT OF MOTION WHILE ALSO LIFTING
NORTHWARD. THIS MEANS THE HEAVIEST PRECIPITATION WILL OCCUR NEAR
THE SC/NC COASTLINE EARLY IN THE PERIOD AS THE LOW BEGINS TO
INTENSIFY AND THE INFLUENCE OF HEIGHT FALLS EXPANDS INLAND. MODELS
ARE FAIRLY CONSISTENT IN FORECASTING THE HEAVIEST RAIN...INVOLVING
NEAR-SFC BASED INSTABILITY...TO REMAIN OFFSHORE...WHILE LESSER BUT
NONETHELESS SIGNIFICANT PRECIPITATION OCCURS ALONG THE SC/NC COAST
AND OUTER BANKS WITH AREAL AVERAGE 1 TO 2 INCHES NEAR THE
SHORE...AND 0.10 TO 0.25 INCHES AS FAR WEST AS FLORENCE TO
RALEIGH. ONE OF THE BIGGER QUESTION MARKS IS HOW MUCH PRECIP WILL
FALL UP THE COAST INTO THE MID ATLANTIC AND SOUTHERN NEW ENGLAND.
THE ZONE FROM SOUTHEAST VA TO NJ TO EASTERN MA WILL EXPERIENCE
HEIGHT FALLS PERHAPS SIGNIFICANT ENOUGH TO PRODUCE NOTEWORTHY
PRECIPITATION TODAY AND TONIGHT PER ABOUT HALF OF THE MODEL
GUIDANCE. THE OTHER HALF OF THE GUIDANCE IS DRY. WITH DRY AIR IN
PLACE INITIALLY FROM VA NORTHWARD...SOME EASTERLY WARM ADVECTION
MAY BE REQUIRED TO GET ANYTHING HEAVIER THAN A FEW HUNDREDTHS OF
AN INCH...AND THIS APPEARS MORE LIKELY TO OCCUR INTO SOUTHERN NEW
ENGLAND BY SUNDAY NIGHT PER THE MID LEVEL FORECASTS FROM THE
GFS/ECMWF RELATIVE TO THE SHAPE OF THE COASTLINE.

THIS THINKING WOULD SEEM TO FAVOR SOLUTIONS LIKE THE GEFS
MEAN...NAM CONUS NEST...AND TO SOME EXTENT THE GEM REGIONAL. OUR
IN-HOUSE BIAS-CORRECTED ENSEMBLE IS ALSO CLOSE TO THESE...ALTHOUGH
IT MAY BE SPREADING PRECIP A BIT TOO FAR INLAND UNDER THE
INFLUENCE OF THE MORE AGGRESSIVE SREF MEAN. TO TEMPER THAT...WE
TOOK A 40/40/20 BLEND OF OUR BIAS-CORRECTED ENSEMBLE WITH THE 18Z
GEFS MEAN AND 00Z NAM CONUS NEST...AND USED THAT OUTPUT AS A
TEMPLATE FOR ADJUSTING THE PREVIOUS WPC FORECAST...TO MAINTAIN
CONTINUITY.


...UPPER MIDWEST / GREAT LAKES / OHIO VALLEY...

THE HEIGHT FALLS THAT HAVE BEEN RACING EASTWARD FROM THE NORTHWEST
U.S. INTO THE NORTHERN PLAINS WILL BEGIN TO SLOW AS LARGE SCALE
AMPLIFICATION OCCURS ACROSS THE COUNTRY...RESULTING IN A LARGE
TROUGH OVER THE MIDWEST. WHILE MODERATE TO STRONG LIFT WILL OCCUR
ON A BROAD SCALE...PRECIPITATION WILL BE BATTLING DRY AIR AT LOW
LEVELS. THERMODYNAMICS AND/OR DEEP LAYER RELATIVE HUMIDITY SHOULD
PROVE MORE FAVORABLE FOR 0.10 TO 0.25 INCH MELTED ACCUMULATIONS
WITH NORTHWARD EXTENT...NEAR THE CENTER OF THE H7-5 TROUGH...FROM
NORTHERN MINNESOTA TO NORTHERN LOWER MICHIGAN. PRECIPITATION
EFFICIENCY WILL BE AIDED SOMEWHAT BY LAKE EFFECT ON LOCAL
SCALES...BUT ALSO AN ARCTIC FRONTAL BOUNDARY DRAPED ACROSS THE
TRACK OF THE SURFACE LOW PRESSURE CENTER THROUGH THIS REGION.
FARTHER SOUTH...MODELS PRODUCE WIDESPREAD VERY LIGHT ACCUMULATING
PRECIPITATION AS THE TROUGH DIGS AND ARCTIC AIR PUSHES THROUGH THE
MID MISSOURI VALLEY...AND DOWNSTREAM FLOW BECOMES INCREASINGLY
DIFLUENT ALOFT TOWARD THE OHIO VALLEY. THE PREVIOUS WPC FORECAST
PROVIDED A GOOD STARTING POINT...AND WE REFINED SOME OF THE
DETAILS USING HIGHER RESOLUTION GUIDANCE...BUT WITH LITTLE OVERALL
CHANGE TO THE GOING FORECAST.

BURKE

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

24HR QP VT 08/12Z
 0.01 416638 421641 425644 432655 438667 436678 433691 429704
      419724 416729 412734 404743 396752 388758 382759 378763
      374767 371774 365796 362803 359807 355811 349815 340819
      336822 329823 324825 317826 311825 306822 301819 298816
      291808 285799 277790 274787 269784 264783 257783 250784
      245783 242779 245774 250766 255757 262749 271741 289729
      322700 327691 333684
 0.01 538205 538188 533176 530174 528170 525170 520167 516167
      509167 504167 501167 501170 502176 507188 512192 516198
      518204 519212 522217 526220 530218 534214 538205
 0.01 518276 519269 519264 518258 516253 511237 506230 503227
      499226 494218 492212 486207 477207 471208 465211 464219
      472217 476218 478217 482218 486220 492221 495223 497227
      501236 502243 500246 498243 493235 486231 480228 472226
      468227 466230 465240 463242 459242 454246 449253 444260
      446265 454269 463272 471274 475275 478275 487278 494283
      502287 506289 509288 515283 518276
 0.01 512276 513274 512272 512271 511270 510269 509270 508272
      508275 509276 510277 512277 512276
 0.01 517957 516951 516942 514936 514929 510913 509907 508900
      505885 503872 503859 505847 504834 501821 496809 492797
      486788 482783 479779 475777 468774 463772 460770 456772
      454777 455781 454785 449782 443782 439784 431789 424792
      415796 406800 396804 389808 379814 370820 367822 363826
      359833 357837 357844 356849 354852 352858 355862 362865
      366876 368880 371884 374884 376881 380878 384875 402869
      410864 415863 418864 419867 421872 424872 425869 428864
      429859 430856 432855 435854 438856 443861 446863 448865
      448869 449876 450882 447887 444889 442892 439892 434892
      413885 409884 407882 397883 394885 392886 390888 385897
      382901 380906 380918 380925 385929 391936 395938 397941
      404947 409956 410959 414961 421970 426978 433983 437988
      441990 448995 455998 461998 465996 470996 472997 473001
      476013 481022 488028 493027 496023 501014 503006 510983
      512976 515968 516961 517957
 0.01 496655 495648 491643 484641 478643 476643 474647 470651
      469654 464665 461671 460676 457688 455693 454698 450710
      450716 449721 446727 445733 445741 446744 448744 456723
      460711 464703 472693 479686 492669 494666 496663 496655
 0.01 253826 253820 251816 249812 247808 245804 243800 240803
      240809 241815 242821 244825 246829 249831 252828 253826
 0.25 502278 503272 503268 501262 498257 494251 491247 488244
      486248 487253 488255 491261 493267 496273 500277 502278
 0.25 490881 489865 489858 487854 483846 479837 475827 472816
      470811 466808 460804 451802 443802 438803 435807 437812
      442812 445812 450814 454815 456818 460822 462827 463832
      463839 464846 466851 472856 478863 481872 485883 488885
      490881
 0.25 471910 471907 471905 471902 471900 471897 470896 469895
      468895 467895 465898 464900 464903 464905 464908 464910
      464913 465914 467915 469914 470912 470911 471910
 0.25 419673 418664 416659 413653 408649 404647 399647 390649
      377654 366661 359667 351674 342682 334690 329698 321706
      305722 302726 299730 295739 289748 282758 275764 271768
      270773 275774 281775 287776 291780 295791 301799 309806
      314809 320810 326810 331809 340804 349798 353793 356788
      360777 364769 370759 378749 392734 399726 406716 410707
      414696 418683 419673
 0.50 413675 412667 410660 407655 403652 395651 384654 374658
      364665 351678 343684 336692 324706 318713 311722 308725
      306730 303738 292756 300768 297779 298785 299790 306797
      312801 317803 321804 328804 335802 342797 348791 351787
      353782 358771 363762 368755 373748 381739 393725 398718
      404708 408699 411689 412680 413675
 1.00 404680 404673 402667 400662 397660 390658 386657 381659
      355681 340693 334698 330705 320718 316726 315733 312754
      314763 311769 306776 305781 305787 311792 317795 324797
      330797 335795 342790 345785 353767 362754 382729 387721
      392713 399697 403687 404680
 1.50 397682 397676 396673 390667 386666 382665 377668 371675
      365679 354688 342698 338699 335702 332707 327714 324721
      322728 321735 316769 312775 310779 311785 316790 322792
      331791 337789 340787 346774 348767 352760 360749 370737
      375732 378726 391699 395689 397682
 2.00 390683 387677 384678 381679 368684 363688 356693 354695
      353698 351704 348706 345705 339705 333715 329721 327728
      326735 327744 330751 328759 325764 320769 316774 315777
      314782 319787 322788 326788 331787 335785 337783 342772
      345765 349759 356750 361745 365738 372729 376723 379716
      384703 388693 390683
 3.00 363729 360728 356730 353735 344744 340750 338755 334762
      330766 321776 321778 321782 327781 333777 337773 344761
      347755 351751 359741 362734 363729
 3.00 337729 336727 335727 334728 335730 335732 336732 337730
      337729

$$





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