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
000
FXUS04 KWBC 141858
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
258 PM EDT SAT OCT 14 2017


PRELIM DAY 1 QPF DISCUSSION
VALID OCT 15/0000 UTC THRU OCT 16/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...CENTRAL PLAINS / MIDWEST / LOWER GREAT LAKES...

ALTHOUGH THE AIR ASSOCIATED WITH THE TROUGH IN THE WESTERN/CENTRAL
U.S. IS NOT PARTICULARLY COLD...IN TERMS OF PRECIPITATION STYLE WE
DO GET A TASTE OF COOL-SEASON FORECASTING. LOW PRESSURE WAS
FORMING MIDDAY SATURDAY OVER CENTRAL KANSAS...AND PROGRESSIVE
CYCLOGENESIS WILL OCCUR AS THE CYCLONE SLOWLY DEEPENS AND MATURES
ALONG ITS QUICK TRACK UP THROUGH THE GREAT LAKES. THE CONNECTION
TO TRUE SUB-TROPICAL MOISTURE WAS CUT OFF BY RIDGING OVER THE
SOUTHEAST STATES...BUT THE RECYCLED CONTINENTAL AIRMASS OVER THE
MIDDLE OF THE NATION WAS STILL PLENTY MOIST...WITH PRECIPITABLE
WATER GENERALLY 1.20 TO 1.60 INCHES ALONG THE FRONTAL ZONE AND PRE
FRONTAL TROUGH. AT MIDDAY CONVECTION WAS ONGOING...MOST OF IT
ROOTED ABOVE THE SURFACE...FROM KANSAS TO MICHIGAN. GOING FORWARD
IN TIME VEERED LOW LEVEL FLOW AND PROGRESSION OF THE DEVELOPING
SURFACE LOW WILL PLACE THE EMPHASIS FOR PERSISTENT AND REPEATED
LOW LEVEL MOISTURE TRANSPORT AND MODERATE TO HEAVY RAINFALL ALONG
THE DEVELOPING WARM FRONT FROM FAR NORTHEAST KANSAS TOWARD THE
LOWER GREAT LAKES. ACTIVITY WILL DWINDLE FROM WEST TO EAST AS THE
DEVELOPING FRONT SWEEPS THROUGH THIS REGION DURING THE EVENING AND
OVERNIGHT. CERTAINLY THERE IS POTENTIAL FOR REPEATED CONVECTION
AND HEAVY EVENT TOTAL RAINFALL ALONG THE WARM FRONT...AND
MESOSCALE DISCUSSIONS WILL PROVIDE GREATER DETAIL AS THE EVENT
UNFOLDS. FOR QPF...HOWEVER...THE CAPE AVAILABILITY IS SOMEWHAT
LIMITED WITH EASTWARD EXTENT...AND THERE ARE QUESTIONS ABOUT
PRECISE QPF PLACEMENT. SYNOPTIC DEEP LAYER ASCENT WILL ATTEMPT TO
REORGANIZE FARTHER NORTH TOWARD MILWAUKEE AND GREEN BAY AS THE
SOUTHERLY COMPONENT TO FLOW INCREASES OVER THE WARM SECTOR...BUT
ONGOING CONVECTIVE OUTFLOWS AT THE LATITUDE OF CHICAGO MAY PREVENT
THE SURFACE WARM FRONT OR EFFECTIVE FRONT FROM LIFTING QUITE SO
READILY. WPC QPF INDICATES BOTH SWATHS RECEIVING FOCUSED
RAINFALL...AS DEEP LAYER MOISTURE IS AVAILABLE TO THE SYNOPTIC
FORCING FARTHER NORTH...BUT FOR THE HEAVIER AMOUNTS WE STAYED
SOUTH ALONG THE EFFECTIVE FRONT AND MODEL SOLUTIONS SUCH AS THE
12Z WRF-ARW. WITH ANOTHER 1-2 INCH AREAL AVERAGE RAINFALL FORECAST
OVER NORTHERN ILLINOIS AND SOUTHERN LOWER MICHIGAN...AREAS THAT
HAD ALREADY RECEIVED HEAVY RAIN...THIS MAY TIP THE SCALES TOWARD
INCREASING ISSUES WITH RAPID SURFACE RUNOFF / FLOODING. WPC QPF
WAS DERIVED BY BLENDING WPC CONTINUITY TOWARD THE LATEST BIAS
CORRECTED ENSEMBLE TOOLS AND USING THE NAM CONUS NEST AND WRF-ARW
FOR SOME OF THE DETAILS.


...NORTHERN PLAINS / NORTHERN GREAT LAKES...

MODELS WERE IN FAIRLY GOOD AGREEMENT AS TO THE QPF STRUCTURE
WITHIN THE DEFORMATION ZONE / COMMA-HEAD FORMING OVER EASTERN
SOUTH DAKOTA AND TRACKING TOWARD THE U.P. OF MICHIGAN. TIMING IS
SOMEWHAT MORE AN ISSUE...WITH THE NAM BEING SLOW AND THE WRF-ARW
AND GFS PERHAPS A LITTLE FAST. THE WPC MODEL DIAGNOSTICS
PREFERENCE WAS FOR A NON-NAM BLEND. IN TERMS OF MAGNITUDE WE
LEANED A BIT TOWARD THE HEAVY SIDE AT LEAST IN A NARROW SWATH
WHERE THE GFS INDICATED ITS STRONGEST LIFT. THE GRADUAL DEEPENING
OF THE CYCLONE THROUGH 12-18Z SUNDAY SHOULD FAVOR WELL ORGANIZED
PRECIPITATION. OUR QPF APPROACH HERE WAS SIMILAR TO THE REST OF
THE CENTRAL U.S...BLENDING WPC CONTINUITY TOWARD THE LATEST BIAS
CORRECTED ENSEMBLE TOOLS AND USING THE NAM CONUS NEST AND WRF-ARW
FOR SOME OF THE DETAILS. THE RESULTING FORECAST IS SPATIALLY
IDENTICAL TO CONTINUITY...AND COMES UP WITH SLIGHTLY HEAVIER
AMOUNTS.


...SOUTHERN PLAINS...

HEIGHT FALLS AND CONFLUENCE OF 850-700 MB FLOW FAVOR EASTERN
KANSAS AND WESTERN MISSOURI FOR MORE ORGANIZED RAINFALL THIS
EVENING...WHILE A MORE NARROW AXIS OF MODERATE RAINS FORCED BY THE
SURFACE COLD FRONT SHOULD OCCUR DOWN INTO OKLAHOMA AND TEXAS. THE
FORECAST REMAINS LARGELY UNCHANGED...ALTHOUGH WE DO NOTE THE
GROWING MODEL AGREEMENT FOR 1 TO 2 INCH AREAL AVERAGE AMOUNTS OVER
SE KS / SW MO.


...CENTRAL GULF COAST...

HI-RES RUNS IN THE 00Z AND 12Z CYCLES TODAY HAVE SPORADICALLY
PRODUCED SOME HEAVY LOCAL RAINFALL TO OCCUR SUNDAY AFTERNOON FROM
SOUTHEAST LOUISIANA TOWARD SOUTHERN MISSISSIPPI. A WESTWARD MOVING
PLUME OF RICH MOISTURE WILL ENCOUNTER A SLIGHT INCREASE TO UPPER
LEVEL DIVERGENCE AHEAD OF THE CENTRAL U.S. TROUGH...SUCH THAT THE
IDEA OF LOCALLY HEAVY RAIN MAY HAVE SOME MERIT. WE INCREASED AREAL
AVERAGE QPF AMOUNTS HERE...SIMILAR ALSO TO THE LATEST GFS AND
ECMWF.

BURKE

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


24HR QP VT 16/00Z
 0.01 443630 444636 444640 445645 446651 442669 439676 435684
      423696 417701 414703 410705 397717 395717 396714 398705
      400696 402687 407670 409661 413654 417646 423640 427635
 0.01 537210 539201 538194 534184 527175 521166 510164 506165
      504166 503171 504177 506183 513192 517203 521213 526216
      531217 537210
 0.01 519265 519260 519257 518249 512234 510227 506221 500218
      493217 493220 496223 496227 493228 489234 488238 486241
      482245 480257 484261 488264 487269 487274 488278 492283
      499286 506285 510281 514275 519265
 0.01 527700 525687 521674 518665 514655 503644 496637 492637
      487640 480644 476646 473649 469658 463668 459671 456676
      452689 447710 444720 440729 430742 425751 419759 414766
      410773 396791 384805 372817 360830 355837 348844 339857
      335865 329873 327876 325878 323876 317872 314867 309865
      304866 301869 296877 295881 292883 286886 283891 281896
      278900 273919 269926 262932 257937 254940 252944 245962
      244967 246969 254973 257974 263973 267972 271968 272964
      274960 279953 284943 288934 301921 313909 316906 321905
      329904 334902 337900 342895 356882 367871 379855 385846
      392839 395836 394841 393847 390851 379866 373873 369879
      360896 356903 351910 346919 340924 327936 319943 315950
      309960 304968 293982 289980 284981 278984 268996 262996
      257997 251997 247999 248004 251007 259012 265016 269018
      275019 289013 295010 298007 304000 307996 309998 310003
      309007 308014 307019 303025 297033 297038 300042 299048
      301051 303053 302055 299058 292062 288063 285060 280053
      276051 270052 265055 261059 259064 255066 254071 257075
      263081 271085 277091 284094 295094 297091 298085 301082
      304080 307077 308072 309065 310060 311053 312047 316041
      322034 331030 345017 353011 360004 371991 382978 387971
      394964 399959 405952 420943 424945 427946 427950 428962
      434970 441978 445981 450980 459977 462975 465972 469964
 0.01 469964 479945 485922 486917 486909 492899 495890 498878
      502868 506857 508846 507828 507820 507812 508805 510800
      513790 517780 522755 527730 527716 527700
 0.01 522044 522036 520032 517027 516020 513011 509998 505989
      502985 502980 504975 504967 501954 497946 493942 489941
      489947 490952 488967 487972 488978 489985 487989 487995
      488000 489007 491013 491018 493024 497026 500031 502035
      507036 513044 515046 518047 522044
 0.01 384713 383710 380711 375713 370716 364719 354726 346734
      342738 339744 337749 337753 338756 342756 349754 358748
      367740 375731 381721 384713
 0.01 303812 302806 299803 296803 291805 288805 286804 284799
      278792 273792 269790 266786 261785 253786 245791 238797
      236801 236807 236818 238832 242832 245829 248825 254826
      260831 266837 274841 280834 288831 296824 300819 303812
 0.25 533209 534201 533195 531191 528188 526182 523181 523185
      522188 521192 522200 523204 526208 529210 532209 533209
 0.25 504249 504251 504249
 0.25 512699 511692 509683 504671 501666 497662 489658 484658
      480660 472670 465680 459694 456706 453718 450731 446741
      439751 434763 437766 439773 438780 436787 432799 429811
      428817 426826 422836 416848 410859 404870 396876 392879
      387882 381890 378896 376902 371911 368916 366921 361932
      356945 350957 345967 338974 336996 332999 328997 324998
      322002 316016 314029 318028 323025 327022 329017 332012
      335008 344002 349998 355995 360991 364987 370979 377970
      388952 394944 398940 403937 417918 423915 428918 434916
      438913 442910 447908 450911 451919 449934 447941 444945
      440949 438953 438959 441964 445967 451967 455966 460963
      464957 468945 472934 475920 477906 479889 484875 488863
      493848 504794 510762 512747 513731 512699
 0.25 435649 435643 432642 426647 421653 418659 415666 412673
      412679 416677 422681 427676 431668 433660 434652 435649
 0.25 427788 427784 424782 420785 419787 417790 416793 415795
      416800 418802 419801 422800 423798 425795 426791 427788
 0.25 367730 366727 364727 360729 356732 354735 351739 348742
      345745 350745 353742 357740 360738 363735 366732 367730
 0.25 365851 364849 360849 354854 350859 346865 342871 341874
      340880 343880 345877 350872 355867 360861 364856 365851
 0.25 313892 312882 311875 308872 305874 302878 302883 300887
      293893 288899 284908 285914 288917 293916 297915 304909
      309903 313894 313892
 0.25 301070 301067 300066 299066 297066 295066 294067 293067
      292069 291070 290071 289072 288075 289075 291075 292075
      294074 296073 298072 300071 301070
 0.25 287079 287078 285076 283077 282078 281080 283081 285081
      285080 287079 287079
 0.25 284005 284003 284001 283001 282003 284005 284006 284005
 0.25 277935 272936 265939 261944 257949 253956 252960 254964
      256966 261967 265966 267964 270957 272949 276941 277935
 0.25 267823 266820 266817 264813 263811 262809 258808 256810
      256814 257818 258819 260821 262823 264825 266825 267823
 0.25 244811 244809 244807 243805 241807 241809 240811 240813
      240815 240817 242816 243815 243813 244811 244811
 0.50 360734 359734 360734
 0.50 506701 505693 504686 499674 497670 493667 489666 484668
      474677 471681 468686 464697 461706 456730 450752 447758
      445767 443780 437801 431824 428834 423843 418853 414863
      404886 399895 394901 390899 388898 385899 379906 373914
      369924 364933 359945 355957 352966 347977 347984 348988
      353989 358985 365978 377963 383954 388945 393936 399930
      411912 418903 425895 430886 433877 435874 436877 434883
      430892 428898 428902 429905 435905 438902 446894 449894
      452901 454915 456921 456928 455934 453940 448949 447955
      449959 455957 458954 464941 467930 472905 474891 476878
      483854 488841 491828 496804 499792 502780 506753 506746
      505735 504728 503720 506701
 0.50 429656 429654 428652 427653 425655 424657 425660 426661
      428660 429659 429657 429656
 0.50 311892 311888 310886 309882 307880 305882 303888 300893
      295897 291900 288906 289910 292911 297910 302905 306901
      309897 311892
 0.50 326012 327010 326008 326007 324007 322009 322011 322012
      321014 320016 320018 321020 323018 325016 325014 325013
      326012
 0.50 267956 267954 267952 267949 267947 267945 266945 265947
      264947 263948 262949 261951 260952 259954 258956 258958
      259960 261961 263961 265960 266958 266957 267956
 1.00 496706 496696 494685 490678 486679 477689 473695 470701
      467707 465715 461731 453762 449776 447792 446802 445809
      444819 446826 449828 453823 458817 461810 465796 467788
      468779 472765 475757 477749 484739 487731 490724 494715
      496706
 1.00 479837 479829 477823 475821 471821 466826 463832 461839
      456855 454863 453872 456878 457883 458888 459896 461905
      463906 465903 467895 470878 472869 473860 475852 478845
      479837
 1.00 435840 436837 434836 432840 428845 420858 414873 408889
      402903 399910 398916 401918 410906 414901 420895 424891
      428883 431865 433845 435840
 1.00 389922 387920 387915 388912 387909 383911 377918 375921
      373927 374930 374933 371936 368945 372953 375954 378952
      383945 386936 389924 389922
 1.00 367949 368947 366947 364949 366950 367949
 1.50 489701 489695 487693 481695 477701 473707 470712 467720
      465728 464735 462743 461753 461761 459768 459773 460773
      463765 465758 468752 471745 473738 476731 480724 485712
      488706 489701
 1.50 470848 470843 469843 467846 466848 465852 464856 463859
      463864 464867 465866 467861 467858 468854 469851 470848
 1.50 428855 427852 425855 421862 419870 416878 413887 411894
      410898 411900 417895 422889 425883 426878 426871 427862
      428855
 2.00 417891 420884 423871 423869 421872 418882 415891 417891

$$





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