Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 031828
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
227 PM EDT FRI JUL 03 2015


PRELIM DAY 1 QPF DISCUSSION
VALID JUL 04/0000 UTC THRU JUL 05/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...MID MS VALLEY/TN VALLEY/OH VALLEY/MID ATLANTIC...

SHORT WAVES DROPPING INTO THE BROAD EASTERN UNTIED STATES TROUGH
INTERACT WITH MOISTURE AND INSTABILITY ALONG AND SOUTH OF A QUASI
STATIONARY BOUNDARY TO PRODUCE CONVECTIVE CLUSTERS WITH HEAVY TO
EXCESSIVE RAINFALL FROM THE MID MS VALLEY ACROSS THE OH AND TN
VALLEY INTO PORTIONS OF THE MID ATLANTIC. FOR THE MOST PART...THE
WPC QPF WAS BASED ON A BLEND OF THE 12Z GFS/00Z ECMWF...WITH EQUAL
PORTIONS OF THE 12Z REGIONAL GEM/12Z ARW/NMMB USED TO BETTER
DELINEATE THE POSITION OF THE AXIS OF HEAVIEST RAINFALL THIS
EVENING.

CONVECTIVE CLUSTERS CONTINUE TO DEVELOP AND MOVE EAST SOUTH OF A
QUASI STATIONARY FRONT EXTENDING FROM NORTHEAST TX ACROSS THE
AR/NORTHERN
MS/NORTHERN AL/GA...ALONG AN AXIS OF 2.00+ INCH PRECIPITABLE
WATER. THE BEST INSTABILITY REMAINS SOUTH OF THE BOUNDARY...AND
THE COMBINATION OF THE FRONT SLOWLY SAGGING SOUTH AND OUTFLOW
BOUNDARIES PUSHING SOUTH SHOULD RESULT IN THE AXIS OF HEAVIEST QPF
EXTENDING FROM THE LOWER MS VALLEY ACROSS NORTHERN AND CENTRAL
MS/NORTHERN AL INTO PORTIONS OF NORTHWEST GA/EASTERN TN. MOISTURE
(IN THE FORM OF PRECIPITABLE WATER VALUES BETWEEN 1.75 AND 2.00
INCHES) AND INSTABILITY REMAIN IN PLACE THROUGH THE EVENING
HOURS...AS A FIRST SHORT WAVE CROSSES NEAR THE FRONT...AND THE
THREAT FOR FLASH FLOODING CONTINUES THROUGH THAT TIME. THE 00Z
ECMWF WAS THE FURTHEST SOUTH WITH THE MAIN AXIS OF QPF SOUTH OF
THE FRONT...WITH MOST OTHER MODELS FURTHER NORTH (INCLUDING THE
MAJORITY OF THE HIGH RESOLUTION GUIDANCE). THE AXIS OF HEAVIEST
QPF WAS PLACED CLOSER TO THE POSITION OF THE 12Z GFS/12Z REGIONAL
GEM...FURTHER NORTH THAN THE 00Z ECMWF.

THE NEXT SHORT WAVE IN THE FLOW TRACKS FROM KS/MO ACROSS THE OH
VALLEY INTO THE NORTHERN MID ATLANTIC BETWEEN 4/06Z-4/12Z...WHICH
SPINS UP A SURFACE WAVE OVER NORTHERN WV AROUND 4/06Z. THE 20 TO
30 KNOT LOW LEVEL FLOW BACKS AHEAD OF A DEVELOPING WARM
FRONT...ALLOWING 1.75 INCH PRECIPITABLE WATER TO RIDE UP AND OVER
THE WARM FRONT. MODEL SOUNDINGS SHOWED MARGINAL INSTABILITY AND A
MOISTENING COLUMN...SUGGESTING WARM RAIN PROCESSES BECOME MORE
IMPORTANT WITH TIME. AN ASSOCIATION WITH THE LIFT AND MOISTURE
WITH THIS SYSTEM...A LONG AXIS OF 1.00 TO 1.50 INCHES OF QPF WAS
STRETCHED FROM EASTERN TN ACROSS EASTERN KY THROUGH MUCH WV INTO
CENTRAL PA. THE LOW LEVEL INFLOW FAVORS THE TERRAIN FOR HIGHEST
QPF AMOUNTS...AND THE MAJORITY OF THE GLOBAL AND HIGH RESOLUTION
MODELS PLACE THEIR QPF AXIS HERE.


...WESTERN STATES...

MONSOONAL MOISTURE COMBINING WITH MARGINAL TO MODERATE INSTABILITY
COULD LEAD TO ISOLATED FLASH FLOODING ACROSS PORTIONS OF THE
SOUTHWEST STATES...MAINLY AFTER 4/00Z. A LOW LEVEL EAST SOUTHEAST
FROM FROM THE SOUTHERN PLAINS TRANSPORTS 1.25 PRECIPITABLE WATER
AIR IN NM...WHILE THE MONSOONAL FLOW BRINGS 1.75 INCH PRECIPITABLE
WATER AIR IN SOUTHERN AZ. MODEL SOUNDINGS SHOWED MARGINAL TO
LOCALLY MODERATE INSTABILITY...
WHICH APPEARS TO PEAK AFTER 4/00Z ACROSS SOUTHEAST AZ/SOUTHWEST
NM. WEAK SHORT WAVES IN THE MID LEVEL EASTERLY FLOW COULD PROVIDE
LOCAL SYNOPTIC LIFT FOR CONVECTIVE DEVELOPMENT THROUGH 4/00Z...BUT
IT IS NOT CLEAR IN THE GUIDANCE WHEN/WHERE THIS OCCURS. THE HIGH
MOISTURE CONTENT OF THE AIR COULD RESULT IN LOCAL FLOODING
ISSUES...BUT LOCATING THESE PLACES IS PROBLEMATIC.

THERE IS A MULTI MODEL SIGNAL THAT A WEAK SHORT WAVE RUNNING
WESTWARD AT THE BOTTOM OF THE WESTERN UNITED STATES RIDGE COULD
SPARK AN MCS ACROSS NM/AZ. NAM SIMULATED SATELLITE IMAGERY
SUGGESTS AN MCS WILL FORM OVER WEST CENTRAL NM/EAST CENTRAL AZ
AFTER 4/02Z...WHICH TRACKS WESTWARD ACROSS AZ THROUGH 4/09Z. WHILE
MOST MODEL QPF OUTPUT ACROSS THIS AREA IS GENERALLY UNDER AN
INCH...THE HIGH MOISTURE CONTENT OF THE AIR COULD RESULT IN HIGHER
RAINFALL RATES WITH THE MCS.

OVER PORTIONS OF NORTHERN NV AND NORTHERN CA...PRECIPITABLE WATER
VALUES VALUES TOPPING OUT NEAR 1.25 INCHES (WHICH IS BETWEEN THREE
AND FOUR STANDARD DEVIATIONS ABOVE THE MEAN) WILL FUEL SCATTERED
CONVECTION DEVELOPING IN AN AREA OF DIFFLUENCE AND MID LEVEL
DRYING. THE CONVECTION PROBABLY REMAINS FAIRLY SCATTERED THROUGH
THE AFTERNOON AND EVENING HOURS...ESPECIALLY OVER THE SIERRA
NEVADA RANGE THROUGH NORTHERN NV. WHILE BASIN AVERAGE QPF SHOULD
RANGE BETWEEN 0.25 TO 0.50 INCHES...LOCAL AMOUNTS COULD EASILY
EXCEED AN INCH OR MORE...PARTICULARLY WHERE TRAINING OCCURS IN THE
MID LEVEL SOUTH SOUTHEAST FLOW.


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

HAYES

24HR QP VT 05/00Z
 0.01 400643 406648 411654 418664 424678 430689 437696 443703
      449714 456727 454743 452752 450757 448763 445770 443776
      439780 433789 426796 419804 409812 404816 399821 391832
      389838 387846 385859 368905 364940 369951 370958 370965
      363976 361981 357983 352985 351991 351997 351002 350004
      349013 345017 342011 340005 337988 332980 329974 323973
      321971 317971 313974 308977 305982 301994 297998 294000
      289000 277996 272994 269992 268988 261980 259977 257974
      257971 257964 260961 267955 272951 274947 274943 273923
      273918 274915 275907 276901 276892 278889 277885 276880
      272876 270872 264865 260860 258856 258848 263845 268841
      270838 266837 262833 259828 256823 249822 247820 247816
      248811 252807 255803 256801 259799 264799 271799 276800
      285803 292804 300804 307804 312800 323793 327790 331787
      332783 332780 332773 333769 336764 343756 335747 333743
      333739 331728 332713 334708 337701 340698 344694 349684
      357677 374660 387647
 0.01 567902 565893 563882 561876 558871 551863 545860 536861
      531870 527879 523891 521899 520909 518923 517930 516939
      516948 516956 515970 515973 512974 508974 502974 498972
      489967 480962 476957 472954 456944 449936 445930 440920
      436909 436904 434901 436893 435885 435881 434879 430878
      428878 428882 429899 429904 431907 431911 435923 436928
      439931 442940 444943 445947 449952 457959 464964 468968
      470973 477990 488008 491015 492019 491022 485032 479041
      477045 476053 475068 475074 477077 481080 486078 489077
      494074 495079 496088 495097 496104 496113 496121 496129
      495136 482125 478124 475126 470129 469133 482138 487141
      489146 489149 492151 496154 500157 503160 507162 510163
      510167 510175 511178 514183 517185 526183 530180 533174
      536161 535144 538130 540114 541102 547094 549089 553086
      556078 557069 560055 561049 562046 563037 564020 565990
      566972 566963 566952 567910
 0.01 527708 525698 524692 519681 514675 511671 507669 504672
      502677 497687 495696 490706 479749 476752 473753 471758
      471765 468769 464775 461779 460785 458799 455811 454837
      451850 451856 453862 469861 475860 480859 483855 485849
      482842 482835 486832 487836 488841 492841 499835 504827
      508820 514809 517798 522776 526763 528751 528736 527729
      526724 527708
 0.01 461106 461101 460101 456099 455097 453082 452076 450070
      447066 445063 443058 444055 445040 447034 449030 456021
      459016 461012 452007 432011 429008 427006 426008 421015
      416022 414025 412028 409026 405023 400020 390015 385013
      382014 374019 368023 360027 354034 349042 338037 331038
      328041 324043 322050 325059 329068 330073 325073 316071
      304069 282061 265051 239031 234035 234044 234050 236055
      240064 245072 250078 257082 272093 282100 289107 286108
      289112 296118 299121 302125 306126 308129 311131 315129
      320119 333117 338120 339126 342131 346133 356136 363133
      366130 369132 371133 372127 380131 384129 391128 395124
      399122 402120 407117 410113 411108 412101 410096 408093
      407087 407082 409078 414076 417076 420079 423082 425090
      427096 426100 424100 418107 424112 428112 431114 439113
      444115 448119 454115 461106
 0.01 422233 422231 420229 420223 421217 423214 426206 423200
      420197 415195 413191 412187 410178 410169 411155 412150
      411145 411139 409138 402137 395140 391141 388144 387147
      388150 393154 392159 389162 383163 378164 377166 382172
      386180 386182 383184 377181 369179 361177 358179 357183
      360188 366193 378204 391212 399217 406220 410223 407224
      401226 394228 394232 397235 402240 410242 419240 422233
 0.01 312156 311156 310154 310153 308153 307155 308156 309157
      311156 312156
 0.01 255814 253814 255814 255814
 0.25 564930 563909 563899 561891 559885 556884 552884 548888
      545895 542902 538915 537922 537930 538947 527971 523983
      518993 511004 509009 507017 507026 508031 511035 515038
      521038 525041 524048 522055 520062 518067 515073 513079
      515099 514111 516128 516143 518159 525169 528167 530160
      530146 530126 531116 532109 536094 538087 538078 543062
      548050 552037 555026 557016 559005 558995 558985 562952
      564930
 0.25 520726 520718 518711 514705 508703 505704 502707 497715
      495725 495737 492744 488753 483759 479767 480771 483772
      490777 494782 498784 502785 509785 512782 513777 515767
      517756 518745 520734 520726
 0.25 433766 433759 432752 431746 430740 429728 427720 425711
      422705 418702 410702 406702 402704 398710 395717 393725
      391731 387735 379747 378751 375755 370761 357763 353768
      352776 357792 357799 357805 354812 351820 348825 340834
      332844 327851 324853 320854 311856 308861 309870 311876
      314883 316892 318896 320900 320911 320922 320931 321938
      323944 325951 328958 334966 338971 342976 346977 347973
      347955 347939 346934 344930 345921 349905 355894 357887
      359879 362870 365863 371850 374844 377838 385827 390820
      394814 403804 413797 418792 422787 426782 430776 433766
 0.25 399206 398200 397196 396193 392190 387191 380190 375186
      370184 366183 362184 364185 367188 371190 376194 381199
      387203 390206 393207 399206
 0.25 385696 383692 379691 375690 370692 363698 357705 354712
      353718 354724 357726 360727 367722 375718 382711 385703
      385696
 0.25 380078 378069 377066 374064 371062 374060 377059 379055
      373050 365049 357049 353050 349048 342045 336046 332052
      330057 333060 339064 346066 352062 357064 360077 365083
      371086 374082 377082 380078
 0.25 372073 371071 371070 369069 368068 367068 366068 367070
      369072 369073 371075 372073
 0.25 355118 353113 350109 347104 347099 349086 349076 343074
      341073 338073 331079 327090 329095 331099 337101 341104
      347112 349117 354118 355118
 0.25 310094 308085 304080 298076 293075 289075 281076 276077
      274079 279084 280088 280090 284095 290098 297101 302102
      305100 309096 310094
 0.25 300819 295815 291814 286811 280810 275809 269811 265815
      268818 274821 279823 287822 294821 298821 300819
 0.50 561916 561903 554903 549910 546920 545926 544934 545949
      542963 539971 534982 532992 531004 536011 538011 539015
      540019 543019 546015 545006 549998 555975 558962 559950
      559925 561916
 0.50 544030 544028 544027 543027 542027 541028 540030 539032
      539033 539035 539038 538040 539042 540043 541043 541041
      542039 542038 543035 544033 544031 544030
 0.50 535064 535059 534058 532059 530062 528065 527068 525071
      524073 523078 524082 527081 528079 530077 531074 533070
      534066 535064
 0.50 526134 526132 526131 525129 524128 523128 522130 522131
      522133 524136 525137 526134
 0.50 512739 510737 508736 506738 505743 505746 504751 504754
      504759 507761 510758 511755 512752 512747 512741 512739
 0.50 425774 426768 424761 421754 417746 414741 418729 417721
      413717 409719 406722 403728 405736 400741 397745 393749
      392757 394766 396772 393776 389777 387779 383781 378781
      374782 372780 371774 369770 364766 358768 356772 357776
      361784 367788 370792 373794 377793 379796 378799 371801
      367807 361813 358819 354826 350831 343840 336852 329865
      327872 327880 325896 324903 324913 325923 325934 326944
      329949 333955 335957 336955 336946 338939 339927 341919
      345904 350892 354877 358860 360854 365847 370837 374831
      378828 397805 401800 406796 416789 422780 425774
 0.50 395203 395200 391197 390195 386194 385193 383193 379193
      379195 381197 384199 386201 389203 392204 395203
 0.50 347061 347059 346059 344061 346062 347061
 0.50 342096 341093 340092 338092 337093 336093 336095 336097
      336098 338098 340098 342096
 0.50 340054 341052 340051 339052 338054 339055 340054
 0.50 339056 338054 336055 334056 333058 334058 336058 338057
      339056
 0.50 304093 304089 303087 301084 299083 295082 292083 290083
      288085 286088 286091 287092 289093 293095 294096 298098
      301097 303095 304093
 1.00 416774 414770 410772 406777 401781 395787 391792 386799
      388801 394796 400792 407788 412783 415776 416774
 1.00 358843 359839 357836 352836 348842 345847 344852 340859
      335867 332876 331887 329896 327907 327919 329931 331935
      333932 334920 337910 341903 344895 350875 350863 349855
      351850 354847 358843
 1.50 347875 346868 344865 340867 337870 335874 334880 334891
      333897 331901 329905 329911 330917 332920 333908 335899
      340892 344884 347875
 2.00 341878 342875 341875 340875 339876 338878 338879 338880
      340882 341880 341878 341878

$$





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