Quantitative Precipitation Forecast
Issued by NWS

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828
FXUS04 KWBC 111900
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
200 PM EST MON DEC 11 2017


PRELIM DAY 1 QPF DISCUSSION
VALID DEC 12/0000 UTC THRU DEC 13/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...GREAT LAKES / NORTHEAST...

WITH A DEEP COLD TROUGH ESTABLISHED OVER THE EASTERN U.S...A
CYCLONE IS FORECAST TO SPIN UP ALONG THE LEADING EDGE OF A FRESH
SURGE OF ARCTIC AIR TRACKING THROUGH THE NORTHEAST QUARTER OF THE
NATION. THE SYSTEM WILL PRODUCE AN INLAND SURFACE LOW TRACK
ROUNDING FROM THE NORTHERN OHIO VALLEY TO CENTRAL AND NORTHERN NEW
ENGLAND...THOUGH THE LOW MAY GET CLOSE TO COASTAL MAINE. A
PRONOUNCED LEAD SHORTWAVE TROUGH THAT WAS SEEN DIVING TOWARD LOWER
LAKE MICHIGAN THIS AFTERNOON WILL BE THE MAIN DRIVER OF THE
EVENT...ALTHOUGH A TRAILING LARGER SCALE TROUGH AXIS WILL
CONTRIBUTE TO FURTHER DEEPENING ON TUESDAY AS THE LARGER SCALE
SYSTEM TAKES ON A NEGATIVE TILT.

FROM A LIQUID TO LIQUID EQUIVALENT STAND POINT...THE SYSTEM
PROGRESSION...ALONG WITH LOW PRECIPITABLE WATER VALUES / BRIEFLY
PEAKING TO 0.50 INCHES OVER CENTRAL TO NORTHERN NEW ENGLAND / AND
THE DISJOINTED INTERACTION BETWEEN THE LEAD SHORTWAVE AND LARGER
SCALE TROUGH...ARE ALL REASONS TO HOLD THE PRECIPITATION TOTALS IN
CHECK. IN TERMS OF WINTER WEATHER IMPACTS...HOWEVER...CONDITIONS
ARE RIPE FOR SNOW WITH FAIRLY HIGH SNOW TO LIQUID RATIOS OF AT
LEAST 12:1 AND AS HIGH AS 16:1 IN SOME OF THE LAKE ENHANCED SNOWS.
SEE THE WPC HEAVY SNOW DISCUSSION...QPFHSD...FOR DETAILS.

LAKE EFFECT WILL BEGIN OFF LAKE SUPERIOR THIS AFTERNOON...LAKE
MICHIGAN THIS EVENING. SNOW BANDS WILL INITIATE OFF ERIE AND
ONTARIO TUESDAY...WHILE CONTINUING BACK WEST AS WELL...WITH SOME
STREAMERS FLYING ALL THE WAY THROUGH PARTS OF IN/OH TOWARD THE
CENTRAL APPALACHIANS...PER THE HI-RES GUIDANCE. FOR THE LAKE
EFFECT WPC QPF USED HI-RES MODELS WITH A CHECK VERSUS NDFD AS WELL.

THE SYNOPTIC PRECIP EVENT WILL KICK IN OVERNIGHT AS WARM ADVECTION
DEVELOPS FROM THE MID ATLANTIC TO NEW YORK / NEW ENGLAND...WITH
DEEP LAYER ASCENT ENHANCED BY THE LEAD SHORTWAVE. UPSLOPE
ENHANCEMENT LOOKS TO BE IN PLAY DURING MUCH OF THE EVENT FOR THE
MOUNTAIN AREAS IN NEW YORK AND NEW ENGLAND...THOUGH AGAIN THE LOW
PW VALUES WILL CAP THE PRECIP MAGNITUDES SOMEWHAT. THE 12Z 27KM
GFS SHOWED GOOD DETAIL IN THE TERRAIN ENHANCED AREAS AND COASTAL
MAINE...SO IT FORMED THE BASIS OF OUR FORECAST. THE BEST MATCHING
HI-RES MODEL WAS THE 12Z NMMB...SO WE STARTED WITH A 50/50 BLEND
AND THEN MADE SOME MANUAL ADJUSTMENTS.

BURKE

GRAPHICS AVAILABLE ON THE WEB AT
WWW.WPC.NCEP.NOAA.GOV/QPF/QPF2.SHTML


24HR QP VT 13/00Z
 0.01 505281 506275 505271 502263 500256 496249 492247 489244
      482242 475242 469244 463248 458249 454251 451251 445255
      441261 444263 447262 453260 459263 468265 474266 483269
      486271 488275 493281 501283 505281
 0.01 489701 488692 487686 482672 476665 470658 464651 459642
      455639 451638 447638 442639 436641 433644 427647 420648
      411648 402647 388650 382657 379659 376663 371670 360687
      349703 337718 334727 332737 335741 339743 342743 344744
      348747 353746 356745 364738 369731 375726 383720 391712
      393707 396704 400703 402704 404706 404711 402717 402723
      401728 402735 402760 404771 402778 399781 391786 386789
      382793 370808 359820 355829 353835 353841 357841 361839
      363836 367836 371835 376835 380837 384841 385846 389855
      396860 403864 408868 410873 412877 417877 422875 428875
      439874 450874 455877 459881 458896 461902 463905 467904
      478886 481874 479864 476859 474853 472848 471840 471831
      472823 472818 472811 470794 468788 469781 467765 467757
      466753 468750 475743 481734 484726 487715 489707 489701
 0.25 472713 472705 470699 467685 465680 462676 457667 455662
      452659 447659 442660 436666 433670 432675 427685 424694
      423699 420704 416711 415718 415724 414736 415748 418757
      423767 425772 423776 421780 419785 413791 411795 411800
      411812 413819 415821 418820 421817 424815 427817 427824
      430825 438823 446821 451821 457818 459815 460808 458804
      454802 446799 441800 438799 439796 443786 446778 449768
      453758 457749 461740 465730 469721 472713
 0.25 473880 472875 471869 469865 465861 462860 459864 458869
      461874 463876 465881 468884 471882 473880
 0.25 450862 447858 445857 438856 431857 424856 417853 414853
      412856 413861 415864 418867 421868 429867 438867 447865
      450862
 0.25 408676 406670 404668 401666 397666 391668 388670 382675
      371688 362700 354715 353735 358735 361733 366727 377715
      381709 386701 391695 397691 403685 407678 408676
 0.50 455693 455687 453680 452673 449670 445669 442672 437680
      434690 430697 427708 425717 423729 424732 427736 426749
      426760 429764 433765 436767 439763 441759 441752 439746
      439741 440736 439733 438731 441728 446725 446719 447714
      449710 453702 455698 455693
 0.50 455732 455731 453732 452733 453733 455733 455732
 0.50 451735 450735 450736 450737 451735
 0.50 428788 427786 424789 422794 420797 418802 417807 417812
      419809 421804 423799 425796 428791 428788
 0.50 396680 393678 390680 387682 385683 383685 382689 382691
      384692 387691 389690 391688 394685 395682 396680
 0.50 373711 373707 371706 368709 365715 361721 361725 363725
      367718 370715 371713 373711
 1.00 444698 444693 441693 440695 439698 437700 435703 434706
      435710 437711 439712 441711 442708 443705 444701 444698

$$





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