Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 281903
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
303 PM EDT SUN MAY 28 2017


PRELIM DAY 1 QPF DISCUSSION
VALID MAY 29/0000 UTC THRU MAY 30/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...TEXAS AND LOUISIANA...

AT MIDDAY THE CONVECTION IN THE SOUTHERN U.S. HAD REACHED A
DIURNAL MINIMUM IN COVERAGE. A SQUEEZE PLAY WAS UNDERWAY BETWEEN
FLAT RIDGING ACROSS THE GULF AND ELONGATED TROUGHING CENTERED OVER
THE MIDWEST/GREAT LAKES. THE CONFLUENCE ZONE BETWEEN THESE
FEATURES...MARKED BY A STRENGTHENING UPPER JET CIRCULATION...WILL
PROVIDE THE DEEP LAYER SUPPORT FOR RENEWED THUNDERSTORM
DEVELOPMENT THIS AFTERNOON. WHERE THIS FORCING OVERLAPS WITH
INSTABILITY AS AFFORDED BY OUTFLOWS AND DIFFERENTIAL CLOUD
COVER...WILL DETERMINE THE LOCATION OF ORGANIZED CONVECTION FROM
EAST TEXAS EASTWARD. MODELS ARE FAIRLY CONSISTENT IN A LOCAL
MAXIMUM OF RAINFALL OCCURRING OVER THE PINEY WOODS IN THE VICINITY
OF LUFKIN TX...AND EXTENDING BOTH WEST AND EAST FROM THERE. THE
SOLUTIONS ARE VARIABLE AS TO THE INTENSITY AND BREADTH OF THIS
RAINFALL...HOWEVER...PERHAPS OWING TO MID-RANGE DEEP LAYER ASCENT
MAGNITUDES AND POOR LAPSE RATES IN THE LOWER REACHES OF THE MID
LEVELS.

THIS PROBLEM OF WARM AIR IN THE SOUNDINGS...NEAR THE TOP OF THE
BOUNDARY LAYER AND INTO THE LOWER PORTION OF THE MID
LEVELS...BECOMES MORE PRONOUNCED WITH WESTWARD EXTENT. DEEP LAYER
FORCING WILL NOT BE PARTICULARLY STRONG WITH WESTWARD EXTENT...BUT
CONVERGENCE AHEAD OF THE SAGGING COLD FRONT...ALONG WITH SOME
BOOST TO CONVECTIVE INITIATION FROM THE HIGHER TERRAIN OF THE
SIERRA MADRE...MAY BE SUFFICIENT FOR SCATTERED CONVECTION TO
FORM...WHICH WOULD THEN HAVE POTENTIAL TO PROPAGATE OUT AND FIND
THE POCKETS OF DEEPER MOISTURE AND STRONG INSTABILITY THAT WILL
DEVELOP OVER SOUTH TEXAS. THIS ACTIVITY MAY BE FURTHER AIDED BY A
SLUG OF RICH MOISTURE SEEN IN SATELLITE TPW IMAGERY AND IN THE
MODEL MIXING RATIO FIELDS...MOVING ONSHORE THIS AFTERNOON AND
EVENING. GIVEN THE NUMBER OF FAVORABLE FACTORS...ALONG WITH
CONSISTENT SOLUTIONS FROM THE HI-RES MODELS...ESPECIALLY WRF-ARW
AND NSSL WRF...WE DO ANTICIPATE THAT CONVECTION WILL BECOME
WIDESPREAD AND CONSUME THE AVAILABLE INSTABILITY IN SPITE OF THE
OBSTACLES IN THE LOWER PORTION OF THE SOUNDINGS...BUT ARE LESS
CERTAIN AS TO HOW QUICKLY THIS EVOLUTION WILL TAKE PLACE.
ALSO...IT MAY BE THAT EVENING CONVECTION SENDS OUTFLOW BOUNDARIES
THAT THEN SPUR A RE-INVIGORATION OF ORGANIZED CONVECTION ALONG THE
COASTAL FRONT OVERNIGHT...FROM DEEP SOUTH TEXAS EASTWARD AND
OFFSHORE. PER SEVERAL HI-RES MODELS...THIS COULD YIELD A RELATIVE
MINIMUM RIGHT ALONG THE CENTRAL AND UPPER TEXAS COAST...ALTHOUGH
IN A SCENARIO THIS COMPLEX OUR CONFIDENCE IS MEDIUM AT BEST.


...SOUTHERN U.S. FROM MISSISSIPPI TO THE CAROLINAS...

SYNOPTICS WILL BE SOMEWHAT FAVORABLE FOR MODEST AREAL AVERAGE
PRECIPITATION FROM RAIN AND THUNDERSTORMS TO THE SOUTH OF THE
STRENGTHENING UPPER JET AXIS...AND AHEAD OF THE SLOWLY ADVANCING
COLD FRONT. THE LIMITING FACTOR WILL BE OUTFLOWS AND CLOUD COVER
INHIBITING BOUNDARY LAYER RECOVER THIS AFTERNOON WITH EASTWARD
EXTENT AWAY FROM LOUISIANA. WPC MAINTAINED AN AXIS OF MODEST
RAINFALL AMOUNTS THROUGH PARTS OF  MS/AL/GA BASED PRIMARILY ON
GLOBAL MODEL CONSENSUS AND THE LIKELIHOOD THAT THERE WILL BE SOME
RECOVERY AND INITIATION... AND/OR SPILLOVER FROM CONVECTION
FORMING UPSTREAM IN LOUISIANA. THERE ARE A FEW HI-RES SOLUTIONS
THAT PRODUCE VERY LITTLE RAIN THIS FAR EAST...BUT THE HRRR HAS
BEEN MAINTAINING AT LEAST SOME SIGNAL FOR DECENT COVERAGE OF LIGHT
AMOUNTS.

THEN LOOKING FARTHER EAST INTO NORTH CAROLINA...A PATTERN HAS BEEN
ESTABLISHED THE LAST COUPLE OF DAYS...WITH SUFFICIENT INSTABILITY
GENERATED EACH DAY TO SUPPORT INITIATION OFF THE HIGHER TERRAIN
AND WITHIN THE MORE DEEPLY POOLED MOISTURE ALONG A WARM FRONT THAT
EXTENDS UP INTO VIRGINIA. EXPECT RELATIVELY ACTIVE AFTERNOONS
THROUGH MONDAY WITH THE SLOW APPROACH OF THE DEEP LAYER TROUGH OUT
OF THE MIDWEST STATES. WPC QPF WAS BUILT AROUND THE WRF-ARW...OUR
IN-HOUSE ENSEMBLE...AND CONTINUITY.


...NORTHERN U.S. FROM THE UPPER MIDWEST TO NEW ENGLAND...

AS THE CLOSED MID-UPPER LEVEL LOW DROPS INTO THE UPPER MS VALLEY
DURING THE DAY 1 PERIOD THE COLD AIR ALOFT ALONG WITH OCCASIONAL
SHORTWAVE PERTURBATIONS ROTATING AROUND...WILL SUPPORT CONTINUED
SHOWERS WITH LIGHT AREAL AVERAGE AMOUNTS OVER PARTS OF ND/MN/MI.
INCREASING DOWNSTREAM UPPER DIFFLUENCE ALONG WITH THE ARRIVAL OF
THE THE INITIAL UPPER SHORTWAVE/VORT LOBE AND 850-700 MB WARM
FRONTAL ARC WILL ALLOW FOR AN EXPANSION OF SHOWERS AND
THUNDERSTORMS FROM THE EASTERN GREAT LAKES TO THE MID ATLANTIC
THIS AFTERNOON...ESPECIALLY WHERE THE LOWER-LAYER FLOW (SW-WSW)
CAN ENHANCE THE COVERAGE/AMOUNTS OROGRAPHICALLY. DEEP-LAYER
INSTABILITY WILL BE MODEST AT BEST...WITH THE MUCAPES GENERALLY
BETWEEN 1000-1500 J/KG. PER THE HIGH-RES MODELS...THERE REMAINS A
SIGNAL FOR LOCALLY HEAVY RAINFALL...AREAL AVERAGE 0.50 TO 1.25
INCHES BUT LOCAL VALUES OVER 2 INCHES...ACROSS NORTHEAST
OH...WESTERN PA...AND NORTHERN WV.


...WESTERN U.S...

SHALLOW DIURNALLY ENHANCED CONVECTION WILL PRODUCE LIGHT
PRECIPITATION GENERALLY NEAR AND JUST EAST OF THE CONTINENTAL
DIVIDE BOTH SUNDAY AFTERNOON AND MONDAY. COVERAGE AND INTENSITY
SHOULD INCREASE SOMEWHAT ON MONDAY AS PRECIPITABLE WATER VALUES
RATCHET UP TO VALUES SOLIDLY ABOVE 0.50 INCHES OVER NEW MEXICO
WITHIN POST-FRONTAL UPSLOPE FLOW. STILL...GIVEN WEAK FORCING AND
RELATIVELY WEAK INSTABILITY...THE AREAL AVERAGE PRECIPITATION
AMOUNTS WILL REMAIN GENERALLY LIGHT...EXCEPT WHERE GREATER
INSTABILITY WILL WORK ITS WAY UP THE RIO GRANDE INTO THE BIG BEND
AND TRANS-PECOS REGION. MODEL QPFS ARE NOT PARTICULARLY
ROBUST...BUT TRENDS WILL NEED TO BE MONITORED.

BURKE

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


24HR QP VT 30/00Z
 0.01 530178 531171 529167 525159 520153 513148 507143 500138
      497136 493134 489132 486130 483128 479126 474126 473128
      473138 476137 480138 485140 486144 491152 490158 491164
      489173 493174 495178 496184 497187 505190 509183 517180
      524180 528180 530178
 0.01 525941 525933 525926 523922 522915 520902 517889 514881
      508873 502867 495863 491863 489861 486862 482862 478859
      475847 474833 477825 480812 483809 486804 488800 489795
      490790 488785 490774 489758 487754 486745 484741 483736
      479726 474716 478709 482696 484684 481675 475666 472665
      470667 467670 462673 460678 459683 459690 455690 451686
      448685 444683 440684 435685 431684 425676 421675 415676
      410677 406679 402683 400687 397695 393705 391711 390718
      389726 388732 383735 380737 374738 369734 365730 363725
      360722 356721 352722 349726 345734 342743 339753 339763
      340776 336784 335795 337798 337803 336808 335815 333820
      329829 326837 323846 321849 319849 319846 319836 317830
      313829 309831 307836 306846 306859 302867 294882 290890
      286900 278918 273928 271932 267934 259937 255939 252944
      247962 243969 240978 239984 237989 236998 240006 242008
      246011 250013 253016 256020 257026 260036 260040 257041
      254044 251049 249054 253059 255061 261063 265065 269064
      283056 288063 292065 295063 297058 299060 300065 301072
      304081 309088 316095 320096 325097 330097 334102 338109
      342112 347112 351110 352107 351104 350099 350093 350087
      352083 354084 358081 360077 362072 365067 366061 374058
      380058 382063 384067 389068 396064 401063 404065 408068
      413069 420065 430068 433068 432063 426053 422049 419049
      411044 408042 403041 383040 378037 375035 370028 367025
      364026 360028 357033 352041 346046 342049 338047 329046
      326050 328052 327056 329058 334060 337062 336065 332069
      326070 323072 320071 315069 313065 311055 310051 308047
      302041 297035 296028 299025 302022 305018 319981 323972
      327965 334948 339938 344929 354912 362896
 0.01 362896 371884 375878 380873 389861 390857 390854 385852
      374862 372866 369867 364873 358878 354878 351876 354868
      357861 360852 361848 363846 377840 380837 382833 386828
      390828 392831 396839 400844 402846 401849 399853 392865
      381897 380902 379906 376914 375918 375922 379918 384915
      389909 398897 406884 415872 424858 434847 451846 456846
      458848 460853 458858 453862 449869 447872 446877 445882
      444887 441896 441901 443904 447909 451909 454911 457918
      462925 465927 466934 465947 466957 467962 470964 476968
      482970 484973 485975 484978 484982 485986 489994 492998
      495999 501001 509001 509997 508994 507990 502985 500982
      502976 505970 511963 517958 520955 522951 525941
 0.01 454179 454176 453174 453171 451170 451171 451173 451175
      451176 452176 454179 454179
 0.01 456160 457152 454147 450138 448132 448124 449115 448109
      449105 452105 457107 461105 460099 458095 454091 449089
      444089 435085 432087 430085 425083 422087 424092 427097
      428099 427103 424106 422112 427113 429108 431103 434103
      435107 434110 437110 440110 443113 444122 443130 440134
      437139 440151 446157 450161 454162 456160
 0.01 436221 436220 434220 432221 431221 430221 429223 428223
      429224 430224 432225 432224 434223 436221 436221
 0.01 445075 445072 445070 443067 442067 440067 438069 438071
      438074 439074 441075 443075 444075 445075
 0.01 442019 443009 441002 443000 443995 441988 438983 433983
      431983 431987 432995 434000 435004 434006 430009 430011
      434014 439017 440019 442019
 0.01 420235 420233 418231 417231 415230 413231 412233 413234
      414236 414237 416238 418237 420236 420235
 0.01 409110 409108 409105 409103 408100 408098 407100 407103
      407105 407107 409110 409110
 0.01 387201 386198 384196 384195 383194 381194 379194 378192
      376191 374190 374191 375193 376194 377194 379195 380197
      382198 384199 385200 385201 387201 387201
 0.01 268814 268810 266808 265806 264802 261802 259804 256805
      254806 252808 252812 253815 257815 260815 263815 266816
      268814
 0.25 515929 515919 513910 509904 508895 505888 500883 495880
      489878 482879 477882 474888 470895 472904 475912 478918
      479922 481924 491934 496936 502937 509937 514933 515929
 0.25 476765 476757 476749 474741 472736 460719 449705 431703
      423699 417693 413689 410691 405699 398718 396729 393740
      390744 386746 383750 381754 380760 382764 390763 395762
      397759 399759 401764 401769 391787 391800 391803 393804
      397806 399812 402814 403809 405807 408808 415812 418816
      418822 417828 417833 419837 421838 424837 432831 436833
      439834 441833 445829 449827 453826 458823 461820 464816
      466804 469793 471788 471781 472776 474772 476765
 0.25 367759 367753 364749 361745 359743 356738 353737 351741
      352746 354750 356753 357757 359759 363761 365761 367759
 0.25 363778 362768 359764 356763 354759 350759 347758 346761
      345770 345776 347780 351789 349800 349809 350813 350819
      348827 347831 344833 339836 334843 327859 324866 319873
      317882 315890 312899 308905 303909 299911 297910 296908
      295902 294899 291901 290904 284919 282926 277933 273938
      265943 260948 256954 249968 243984 241993 242997 244000
      251003 257008 261015 261019 263023 266027 267032 269036
      270040 270046 273050 275050 279049 284050 289051 291046
      290041 289036 286030 286020 289014 293010 296008 300000
      306985 312970 320955 327941 332924 334915 335904 337896
      339886 339875 343867 346861 350854 354848 357841 361832
      361824 360820 360814 361803 363778
 0.25 366043 364041 362043 360045 357047 355049 354051 355053
      356053 359052 361051 363048 365045 366043
 0.25 342094 342091 341088 339085 337083 336080 334078 332077
      331078 330081 332083 334084 335088 335091 337093 340095
      342094
 0.25 310873 309871 308870 308871 307873 307874 306875 307876
      308877 309878 309877 310875 310874 310873
 0.50 511924 510916 508911 503904 500896 500891 498888 495884
      491883 486884 485889 486896 484902 483907 484913 485918
      488922 491924 495927 499928 504928 509926 511924
 0.50 471753 471746 470740 464732 461729 457728 453730 450730
      446727 445723 446716 443713 438714 435717 432718 429716
      426712 422710 419706 417702 414698 410699 407703 405708
      404718 403725 401728 400734 400737 403738 406740 408745
      410767 409778 407785 403786 400788 398791 398793 400798
      403800 406802 409798 413797 416800 422809 425812 424815
      420826 420832 421833 424832 427823 429818 428815 430812
      433808 434804 436799 437797 440798 447803 447810 449815
      452819 456818 459814 459808 457803 456798 462792 461773
      465772 468766 471759 471753
 0.50 434780 434775 432774 429774 426773 423773 420775 419778
      420783 421785 422787 426787 429786 431784 432783 434780
 0.50 425722 425720 424718 423718 422718 420718 419720 418721
      418724 419725 421725 423724 424723 425722
 0.50 360801 359799 359796 359794 357793 356795 355796 355797
      356799 356801 356803 355806 355808 355810 357812 357813
      357812 359811 359810 359807 360805 360803 360801 360801
 0.50 352777 351773 352771 353769 353768 352768 351770 349774
      349776 349778 350778 352778 352777
 0.50 350848 350844 347844 344839 341840 339842 336847 332856
      329870 325879 327881 327885 326892 323898 320901 313909
      309913 304915 298916 294915 290918 287923 281933 276941
      267946 262949 259954 254963 250973 246984 244992 247997
      256002 263009 265021 269025 271030 276029 279024 278017
      284007 293001 295996 297989 304983 309973 313961 318952
      323941 327931 329924 330918 330905 333894 334881 333874
      335869 341860 345853 350848
 0.50 286045 287043 286041 286040 285039 284038 282038 280038
      279040 278041 277042 277044 278045 280046 282046 284047
      285047 286045
 1.00 466747 465745 462743 460742 456742 453745 451746 450748
      448751 449753 451755 454757 456759 458759 460758 463755
      464752 465750 466747
 1.00 440750 439748 439744 440740 438738 436739 434742 433744
      432747 431752 433754 437754 439753 440750
 1.00 432797 433795 432794 430794 429795 428797 428798 429798
      430798 432797 432797
 1.00 323930 324925 324919 322915 320915 305922 300922 298925
      296927 292926 289927 290932 292934 293939 290958 281970
      278977 275983 273980 274976 277968 279961 281956 281951
      280945 278946 274947 271949 264953 260958 255965 252972
      250980 250986 254994 259998 271006 276005 279004 285999
      289993 291984 294977 296973 299970 303970 307964 312956
      315949 319939 323930
 1.50 460751 460748 458747 457748 455749 455750 456752 457752
      459752 460751
 1.50 317932 316926 314924 310924 305928 303930 300931 301937
      301943 300952 301960 303961 307961 309956 312949 314944
      316939 317932
 1.50 288979 287975 285977 281983 279988 277990 272989 270987
      268982 271974 274968 276960 278957 277953 272957 267957
      265958 260964 256970 253976 252981 253984 255988 259990
      262996 267000 275002 280999 283996 284991 286985 288979
 2.00 314932 314930 312930 308931 306933 305935 304939 305942
      305945 307949 308947 310943 310942 310941 312937 313935
      314932
 2.00 277997 277996 275997 277997 277997
 2.00 272995 271994 271993 270992 268990 266990 264992 265994
      266995 268996 269996 271995 272995
 2.00 272968 272962 270959 266961 264964 261968 259970 257974
      255978 256982 259982 263979 266976 268974 271970 272968

$$




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