Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS04 KWBC 080624
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
123 AM EST MON FEB 08 2016


PRELIM DAY 1 QPF DISCUSSION
VALID FEB 08/1200 UTC THRU FEB 09/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...STORM MOVING UP THROUGH NEW ENGLAND EARLY TODAY...

AN IMPRESSIVE...ALREADY MATURE CYCLONE WITH CENTRAL PRESSURE NEAR
OR BELOW 980 MB AT 06Z WILL LIFT UP THE COAST TODAY. THE STORM
WILL PASS WELL EAST OF THE 70/40 DEGREE BENCHMARK...BUT CLOSE
ENOUGH FOR PARTS OF NEW ENGLAND TO FEEL THE INFLUENCE OF 850-700
MB WARM ADVECTION AND MODERATE TO STRONG 12 HOUR HEIGHT FALLS.
THIS WILL YIELD A WINTER STORM WITH HEAVY SNOW AND STRONG
WINDS...WITH BLIZZARD CONDITIONS ALSO BEING FORECAST IN SOME
AREAS. PRECIPITATION SHOULD BE HEAVIEST FROM EASTERN LONG ISLAND
TO CENTRAL/EASTERN MASSACHUSETTS. NORTHEASTERLY LOW LEVEL WINDS
WILL ENHANCE PRECIPITATION TOTALS VIA OCEAN EFFECT OVER EASTERN
MASS. FORECASTS OF LIQUID EQUIVALENT PRECIPITATION WERE RELATIVELY
STEADY FROM THE 12Z SUNDAY TO 00Z MONDAY MODEL CYCLES. WPC AND
LOCAL NWS OFFICES HAVE LEANED TOWARD SOME OF THE HEAVIER GUIDANCE
OWING TO THE SYSTEM STRENGTH. PRECIPITABLE WATER VALUES RISE ABOVE
0.50 INCHES DURING THE STORM AND EASTERLY 700 MB FLOW PEAKS AROUND
3 STANDARD DEVIATIONS FROM CLIMATOLOGY. WPC MADE ONLY A FEW
ADJUSTMENTS...FAVORING THE 12Z WRF-NMM AND ENSEMBLE CONSENSUS
TRENDS. THE MAIN EFFECT OF THE CHANGES WAS TO TIGHTEN THE GRADIENT
ON THE NORTHERN AND WESTERN SIDES OF THE PRECIPITATION
SHIELD...WITH JUST A VERY SLIGHT REDUCTION OF AMOUNTS FROM
SOUTHEAST NY TO CENTRAL NH AND CENTRAL ME. SEE THE LATEST WPC
HEAVY SNOW DISCUSSION...QPFHSD...FOR ADDITIONAL WINTER WEATHER
INFORMATION.


...COLD TROUGH DIGGING TOWARD THE OHIO VALLEY AND MID ATLANTIC...

THERE IS GOOD LARGE SCALE AGREEMENT AS TO THE AMPLIFICATION OF AN
ELONGATED AND BROADENING UPPER TROUGH STRETCHING FROM THE GREAT
LAKES SOUTHWARD THROUGH THE OH/TN VALLEYS TO THE CENTRAL GULF
COAST. WITH MID SEASON ARCTIC AIR HELPING TO CARVE OUT THE
TROUGH...850 MB TEMPERATURES AND 500 MB HEIGHTS DIP WELL BELOW
CLIMATOLOGICAL VALUES...ESPECIALLY ACROSS THE SOUTH. THE SYSTEM IS
LACKING FOR AN INFLUX OF MOISTURE...WITH THE DEEPER SUB-TROPICAL
PLUME BEING DIRECTED OUT ALONG THE PRECEDING FRONTAL BOUNDARY IN
THE CARIBBEAN AND WESTERN ATLANTIC. COLD TEMPERATURES...STEEP
LAPSE RATES...AND SUSTAINED LARGE SCALE FORCING...HOWEVER...WILL
PROVE SUFFICIENT FOR BROAD AREAS OF AT LEAST 0.10 TO 0.25 INCH
AREAL AVERAGE PRECIPITATION THROUGH TUESDAY MORNING. ON THE LARGE
SCALE PRECIPITATION DISTRIBUTIONS AMONG THE MODELS ARE SIMILAR
WITH ONE MAX IN THE VICINITY OF THE SURFACE LOW TRACK FROM THE
UPPER MS VALLEY INTO THE UPPER LAKES...AND A SECOND MAX ALONG THE
TRAILING FRONTAL BOUNDARY PUSHING EASTWARD THROUGH THE OHIO VALLEY
INTO THE SOUTHERN APPALACHIANS AND MID ATLANTIC. UPPER LEVEL
DIFLUENCE AND LARGE SCALE HEIGHT FALLS WILL BE ESPECIALLY
PERSISTENT ON THE NORTH AND NORTHEAST SIDE OF THE MID LEVEL LOW
CIRCULATION...TRACKING FROM MICHIGAN THROUGH OHIO TO WEST
VIRGINIA. THIS FORCING IS LIKELY TO EXTEND OUT ACROSS THE MID
ATLANTIC THROUGH VA/MD/DC AND SOUTHERN PA MONDAY NIGHT NEAR A
DEVELOPING SURFACE OCCLUSION.

MODEL QPFS WERE GENERALLY SPATIALLY CONSISTENT WITH ONE
ANOTHER...WHILE VARYING IN THE SMALL SCALE DETAILS. GIVEN THE
SYSTEM IS DRY IN A TOTAL PW SENSE...AND PRECIPITATION WILL BE
FORCED LARGELY BY THE MID LEVELS...WITH LOCAL UPSLOPE INFLUENCES
AT LOW LEVELS...THE DISTRIBUTION OF HEAVIER POCKETS OF
PRECIPITATION MAY BE DIFFICULT TO ANTICIPATE. WITHIN THE ZONE OF
PERSISTENT MID LEVEL ASCENT DESCRIBED EARLIER FROM MICHIGAN TO THE
MID ATLANTIC...HOWEVER...QUARTER INCH ACCUMULATIONS APPEAR TO BE A
GOOD BET BASED ON THE ENSEMBLE PROBABILITIES AND AGREEMENT AMONG
THE GFS...WRF-ARW...WRF-NMM...AND GEM REGIONAL. HOW QUICKLY THESE
ACCUMULATIONS BUILD OUT INTO THE MID ATLANTIC IS ANOTHER
QUESTION...HOWEVER...WITH THE 00Z HI-RES GUIDANCE TRENDING
SLOWER...AND HOLDING OFF MORE OF THE PRECIPITATION UNTIL DAY 2.
FOR NOW...WPC NUDGED THE SMALL SCALE DETAILS TOWARD THE 18Z GEM
REGIONAL...12Z WRF-NMM...AND 12Z WRF-ARW...WHILE MAINTAINING A
GREAT DEAL OF CONTINUITY. ONE OF THE MORE SIGNIFICANT CHANGES WAS
TO DRY THE FORECAST OVER UPSTATE NY...WHERE THEY WILL BE CAUGHT IN
BETWEEN THE COASTAL SYSTEM AND THE DEEPER FORCING PASSING THROUGH
THE OHIO VALLEY. WEAK WARM ADVECTION SHOULD YIELD LIGHT MEASURABLE
PRECIP...BUT NOT MUCH MORE THAN 0.10 INCHES FOR MOST OF UPSTATE NY
PER AGREEMENT IN THE ENSEMBLE PROBABILITIES AND MOST OF THE
DETERMINISTIC GUIDANCE.


...COLD FRONT PUSHING INTO THE SOUTHEAST U.S. AND FLORIDA...

THE AIR MASS HAD DRIED SIGNIFICANTLY IN THE WAKE OF THE EARLY
WEEKEND SYSTEM OVER THE SOUTHEAST. A STRONG COLD FRONT APPROACHING
THE REGION TODAY MAY TAP A LIMITED RETURN FLOW OF MOISTURE OFF THE
NORTHEAST GULF...AND STEEPENING LOW LEVEL LAPSE RATES MAY SUPPORT
SHOWERS. ANALOG DATA FROM THE GEFS REFORECAST SUGGESTS A
DISTRIBUTION OF LIGHT PRECIPITATION OVER FL/GA/SC RESEMBLING THE
00Z NAM AND GEM REGIONAL...WHICH WERE CLOSE TO THE PREVIOUS WPC
FORECAST.

BURKE

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

24HR QP VT 09/12Z
 0.01 468621 471622 474621 477625 483636 483642 484649 483664
      485683 486693 485700 477712 473718 466722 463723 461726
      458731 455747 455759 453763 454767 456775 469776 475777
      481781 486783 488791 492805 486816 484824 481829 479836
      481842 483850 486853 492865 494870 493878 490887 488894
      487904 486910 486917 486926 482930 479927 476927 474930
      459941 454944 451945 447945 440945 439939 438937 440933
      440928 441925 440922 438918 435916 429919 421926 417928
      412924 408923 405919 400916 396915 395917 396922 398926
      404931 407931 409933 411934 414938 417943 422949 421954
      417954 412954 407950 398944 392943 387940 384938 381934
      377930 373927 366918 362905 361894 361889 360885 359881
      358877 355872 352867 348871 343873 341871 339866 335861
      331859 329851 329848 330844 333837 337832 339826 337823
      334823 329827 312841 305846 300843 298839 296832 293827
      292822 293816 293811 293804 295796 297793 298789 297779
      296771 298766 304756 308747 314739 328715 335705 343696
      357678 372664 374662 378661 386661 389661 391664 395669
      407662 411659 415653 420644 427635
 0.01 522036 519025 516022 511019 505016 500013 495012 473011
      469013 466011 458005 449005 445008 442012 452027 459033
      467038 472039 475041 478042 480044 483047 486053 489055
      493058 498060 501059 502052 505047 508045 511043 514043
      518043 520041 522036
 0.01 437842 436840 436837 435835 433836 431836 430836 428836
      426836 425839 426841 428840 428841 430842 432843 434844
      435844 437842
 0.01 421744 420742 418743 416742 415743 416745 417745 418747
      420747 421744
 0.01 374754 373749 372745 369741 366744 359748 353753 348758
      345764 342771 342775 346776 353772 358767 365762 370758
      373756 374754
 0.01 288837 288833 286831 285828 283826 281825 278825 277828
      278832 278834 280838 282840 284840 286839 288837
 0.01 272803 272799 268797 257798 252799 248801 244809 243819
      244824 247827 249825 251820 253817 253812 251809 252806
      254804 259801 265802 268806 271806 272803
 0.01 273073 273069 271065 268058 265053 262047 258045 256046
      250048 249053 252056 254063 256069 261076 263077 268077
      273073
 0.25 470646 470641 468638 464636 459637 456635 452635 449636
      442639 433647 418661 411671 403680 400684 394686 390689
      386689 384682 379679 376679 372681 367685 339718 334727
      329734 326740 324745 321758 320764 321769 323769 327766
      336760 345751 352743 357735 362723 364718 372717 378715
      381714 384715 390722 398728 404730 411729 422725 430720
      441712 441706 444698 446693 449689 456682 459677 460671
      463663 466658 469652 470646
 0.25 475887 475882 475877 474875 471873 469875 468880 468883
      467888 466892 466895 466900 468900 470898 471895 473892
      474890 475887
 0.25 468814 466808 464804 458799 448798 443796 440791 436788
      432792 426798 422800 420801 417800 412797 409792 407792
      407789 407783 408778 407775 402771 400765 399758 396752
      391744 392740 391734 389734 387736 386742 385749 384756
      385763 385769 382778 382791 379797 376803 374807 370809
      363814 358821 351832 349836 348841 348844 351844 354844
      367831 373831 377829 385827 396827 400829 405834 409834
      412831 414826 417824 425817 426814 429814 433816 446824
      456829 461830 465827 467821 468814
 0.25 465866 464865 463866 464867 465866
 0.25 423862 422862 421862 420863 421863 422863 423862
 0.50 460649 454643 450642 445643 439649 432658 425663 418671
      413678 407686 401694 398698 397704 398710 400713 403716
      408717 416717 422717 427713 433707 437697 445678 449670
      452665 456660 459654 460649
 0.50 461815 461812 461811 460810 459809 457809 455810 454810
      453811 452812 452814 452816 454818 454819 456820 456821
      458821 460820 461817 461815
 0.50 413816 413813 410812 404811 398810 393808 392805 389804
      385809 380813 379816 381820 386821 392821 399822 404822
      409820 413816
 0.50 401779 400777 400776 398775 397775 396775 395774 394775
      395777 397779 399781 400779 401779
 0.50 379696 379691 377687 374686 372688 371691 370693 369697
      368700 369705 372706 375703 377701 378698 379696
 0.50 363823 363822 363823 363824 363823 362825 361824 361825
362826 362825 355837 355835 354837 355837 355837 354839 353838
353839 354839 354839 358832 358830 357832 356832
      355835 357835 357834 358832
      358832 360827 360828 360827
 0.50 351735 348735 346735 346732 349725 348720 344718 340722
      335730 332735 331738 331744 331748 334752 337752 340750
      345745 349740 351735
 1.00 446656 446653 444653 443654 441656 440658 438660 438661
      437663 437664 437666 438667 439667 441665 442663 443661
      444661 445659 445658 446656
 1.00 434674 431673 428676 425677 421680 418688 414694 411701
      411704 413707 419709 423708 425705 427698 430690 432682
      434674

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.