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
790
FXUS04 KWBC 050659
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
158 AM EST MON DEC 05 2016


PRELIM DAY 1 QPF DISCUSSION
VALID DEC 05/1200 UTC THRU DEC 06/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...SOUTHERN U.S...

WIDESPREAD RAINFALL WILL CONTINUE ACROSS THE SOUTHEAST THROUGH
TODAY. OVERALL EXPECT TO SEE A COMPLEX CONVECTIVE EVOLUTION...WITH
A FEW AREAS OF POSSIBLE EXCESSIVE RAINFALL DEVELOPING. AS OF EARLY
MONDAY MORNING CURRENTLY HAVE A BROAD SWATH OF STEADY RAINFALL
OVER PORTIONS OF CENTRAL TEXAS DEVELOPING IN THE STRONG WARM AIR
ADVECTION AHEAD OF THE UPPER LOW. THIS INLAND PRECIPITATION IS
DISPLACED WELL NORTH OF THE SURFACE FRONT AND BETTER
INSTABILITY...ALTHOUGH DO NOTE SOME WEAK ELEVATED INSTABILITY.
EXPECT THIS AXIS OF SHOWERS AND EMBEDDED CONVECTION TO GENERALLY
MOVE EASTWARD INTO CENTRAL LA THIS MORNING AND TOWARDS CENTRAL
MS/AL BY THIS AFTERNOON. WOULD NOT EXPECT THIS RAINFALL BE TO BE
ALL THAT INTENSE GIVEN THE LACK OF INSTABILITY AS MENTIONED
ABOVE...THUS ANY FLASH FLOOD THREAT SHOULD BE RELATIVELY LOW WITH
THIS ACTIVITY AND DRIVEN BY ANTECEDENT RAINFALL HAVING SATURATED
SOILS OVER PORTIONS OF THE AREA.

EXPECT MORE INTENSE CONVECTION TO FOCUS CLOSER TO THE GULF COAST
NEAR THE WARM FRONT...WHICH WILL SLOWLY LIFT NORTHWARD THROUGH THE
DAY. CAN ALREADY SEE THIS CONVECTION FORMING OFF THE TEXAS COAST
THIS MORNING. THE LATEST HIGH RES HRRR AND ARW (WHICH APPEAR TO
HAVE THE BEST HANDLE ON THINGS CURRENTLY) SUGGEST THIS ACTIVITY
SHOULD MAINLY STAY OFF THE TEXAS COAST. HOWEVER DO ANTICIPATE THIS
HEAVIER CONVECTION TO MOVE INTO SOUTHERN LA THROUGH THE MORNING
HOURS AS THE WARM FRONT LIFTS NORTH. DID LEAN OUR QPF TOWARDS THE
ARW/HRRR WITH THIS ACTIVITY. THIS DID RESULT IN AN INCREASE IN QPF
AMOUNTS ACROSS COASTAL LA FROM OUR PREVIOUS FORECAST.

AS WE HEAD THROUGH THE AFTERNOON HOURS WOULD ALSO EXPECT TO SEE
CONVECTIVE COVERAGE INCREASE FURTHER EAST ALONG THE GULF COAST
INTO THE FLORIDA PANHANDLE. RECENT MODEL GUIDANCE CONTINUES TO
SUGGEST THE PLUME OF MAX PRECIPITABLE WATER AND LOW LEVEL MOISTURE
TRANSPORT WILL FUNNEL INTO THE FL PANHANDLE AND SOUTHERN GA THIS
AFTERNOON. THIS MOISTURE PLUME IS THE RESULT OF ENHANCED LOW LEVEL
FLOW IN BETWEEN THE UPPER LOW TO THE WEST AND THE UPPER HIGH OVER
THE SOUTHERN ATLANTIC. IN FACT ANTICIPATE PWAT VALUES TO SURPASS
2" ACROSS THE FL PANHANDLE INTO SOUTHERN GA...WHICH WILL APPROACH
CLIMATOLOGICAL MAX VALUES. MEANWHILE...ALOFT THE FLOW WILL BECOME
INCREASINGLY DIVERGENT IN THE RIGHT ENTRANCE REGION OF THE UPPER
JET. THUS WOULD APPEAR TO BE A GOOD SETUP FOR WIDESPREAD
CONVECTION CAPABLE OF PRODUCING HEAVY RATES. WILL NOT NECESSARILY
SEE A LOT OF BACKBUILDING CONVECTION...BUT EXPECTED WIDESPREAD
COVERAGE SHOULD RESULT IN SOME TRAINING POTENTIAL. THUS WHILE
OVERALL WPC QPF WAS A MULTI MODEL GLOBAL AND HIGH RES
BLEND...PREFERENCE FOR QPF WAS GIVEN TO THE WETTER MODELS ACROSS
THIS REGION...GENERALLY THE HRRR AND OTHER AVAILABLE HIGH RES
MODELS. A MULTI MODEL HIGH RES SIGNAL EXISTS FOR POCKETS OF 2-4"
FROM THE FL PANHANDLE INTO SOUTHERN GA. THUS THE NEW 06Z WPC QPF
IS AN INCREASE ACROSS THIS REGION FROM OUR PREVIOUS FORECAST.

AS WE HEAD INTO TONIGHT AND THE UPPER LOW BEGINS TO EJECT INTO THE
LOWER MS VALLEY EXPECT TO SEE ADDITIONAL CONVECTION FORM ALONG THE
COLD FRONT FROM EASTERN LA INTO MS...MOVING INTO AL AND GA
OVERNIGHT. COULD SEE SOME LOCALLY HEAVIER RATES WITH THIS
ACTIVITY. MEANWHILE WILL CONTINUE TO SEE A BROAD AREA OF SHOWERS
AHEAD OF THE UPPER LOW PROGRESS INTO THE MID ATLANTIC AND SOME
WRAP AROUND RAIN ON THE BACKSIDE OF THE LOW FROM AR INTO THE
WESTERN OH/TN VALLEY. OVERALL THE TREND AMONGST ALL THE GUIDANCE
WAS FOR A SLIGHTLY FURTHER EAST LOW TRACK...THUS DID CUT BACK QPF
AMOUNTS SOME ACROSS THE NORTHWEST EDGE OF THE PRECIPITATION SHIELD
TO COME MORE IN LINE WITH THE CURRENT MODEL CONSENSUS.


...NORTHERN PLAINS/ROCKIES...

MULTIPLE PIECES OF SHORTWAVE ENERGY CURRENTLY OVER MT/WY WILL
MERGE OVER THE NORTHERN PLAINS RESULTING IN THE DEVELOPMENT OF A
CLOSED MID/UPPER LEVEL LOW OVER ND/MN BY TONIGHT. THE 0Z SUITE OF
MODELS HAVE ALL SHOWN QUITE A CHANGE FROM PREVIOUS RUNS ON HOW
THEY HANDLE THIS SYSTEM. THE TREND HAS BEEN TO CLOSE OFF THE LOW
FURTHER SOUTH...RESULTING IN A FURTHER SOUTH LOW AND MORE
PRECIPITATION OVER ND/MN. THIS TREND WAS SEEN IN ALL THE HIGH RES
GUIDANCE AS WELL AS THE 0Z GFS/NAM/UKMET. IT WOULD APPEAR THAT
THIS SYSTEM WAS VERY SENSITIVE TO THE MULTIPLE SUBTLE SHORTWAVES
INTERACTING...AND THAT RECENT OBSERVATIONS HAVE RESULTED IN THE
SOUTHWARD SHIFT IN THE MODELS. GIVEN THE APPARENT SENSITIVE NATURE
OF THIS SYSTEM...CAN NOT BE 100 PERCENT SURE THAT MODELS DO NOT
SHIFT A BIT BACK TO THE NORTH. HOWEVER GIVEN THE GOOD AGREEMENT
AMONGST BOTH HIGH RES AND GLOBAL MODELS...THOUGHT THE RIGHT COURSE
OF ACTION WAS TO MAKE A PRETTY BIG CHANGE FROM CONTINUITY AND
INCREASE QPF AMOUNTS ACROSS THIS REGION. WPC QPF THUS FOLLOWED
PRETTY CLOSE TO A BLEND OF THE 0Z GFS/UKMET AND THE 0Z HIGH RES
ARW/NMMB AND NSSL WRF. THE OLD 12Z ECMWF WAS NOT USED...GIVEN IT
WAS AN OLDER PIECE OF GUIDANCE AND APPEARED TOO FAR NORTH GIVEN
THE RECENT CONSENSUS.


...PACIFIC NORTHWEST...

A SHORTWAVE TROUGH MOVING INTO THE NORTHWEST TODAY WILL CONTINUE
THE MAINLY LIGHT PRECIPITATION THREAT OVER WESTERN WA/OR. OVERALL
MODELS WERE IN DECENT AGREEMENT ON QPF WITH THIS SYSTEM. THUS WPC
FOLLOWED CLOSE TO A GLOBAL AND HIGH RES CONSENSUS FOR QPF ACROSS
THIS REGION.

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

CHENARD

24HR QP VT 06/12Z
 0.01 507266 508258 508252 506239 501214 500208 498204 495199
      491196 488192 486187 485181 483175 481170 481164 480162
      478164 476162 471152 464146 461143 457145 453147 447148
      440151 436153 435160 436165 434171 429182 419204 420207
      419215 417223 414226 410229 406229 402231 400232 399237
      400248 402254 403259 410267 414266 417266 419269 440303
      443306 448309 459313 464311 467308 472300 477289 479282
      481276 483267 484264 486262 490262 495263 503266 507266
 0.01 526005 523995 517989 514985 515980 515964 516929 515912
      515894 514887 513882 511868 504849 504813 494763 490754
      487751 484745 479737 476732 475726 477717 476705 467687
      466682 463676 457669 449662 443656 440653 438647 436642
      432641 427644 421646 414643 410642 405644 400645 396649
      388655 383658 381660 381664 380667 383672 388681 389685
      385684 375689 360699 356701 353701 349700 344701 336705
      330711 324718 320726 312743 307752 300759 296765 291771
      281785 275792 272795 272798 274805 274808 272810 268810
      265812 259819 254826 249832 245839 242843 241848 240858
      241885 246906 250913 255919 257922 257925 257930 257944
      257957 257963 255968 255973 257976 264980 268982 271986
      274988 275993 279016 281026 284032 289034 296038 300040
      303040 307032 312024 321007 325998 330989 334982 338973
      341969 345967 351962 358957 365950 370943 374938 376933
      377929 377921 380911 387893 393869 395860 396855 396849
      397845 397838 396823 393814 389803 384794 379785 374776
      369765 376758 383753 395745 407743 415750 420757 425763
      431769 437777 443784 446796 446802 449807 452811 454816
      464837 468846 471857 472860 471864 469863 469860 465851
      463846 460846 458849 458858 464883 456883 454884 454886
      449889 442894 436899 432902 430905 426909 427912 436916
      438917 438920 436924 431932 431938 435938 435945 439945
      449943 454943 457945 460946 460949 457954 450971 448976
      450981 452983 456986
 0.01 456986 451005 449010 449016 447022 450027 452029 457027
      459025 462025 461029 460033 457037 451044 447041 445038
      440038 436040 427042 418045 416050 413052 408053 404053
      401051 402048 401041 399044 397049 394046 396051 399055
      395058 388062 384063 385065 388069 386073 383076 385076
      388075 391077 393080 395078 400078 405086 406092 407095
      407099 404103 401106 394110 390113 390117 393121 397123
      397131 397138 392146 394149 398149 407126 411119 414108
      417095 418090 418085 420083 424073 427075 430080 433084
      433089 432093 430098 427103 423105 423107 426110 430110
      438105 443099 442094 442086 444080 448083 452087 455088
      458084 460077 463082 466083 470086 470089 467090 467095
      468098 468103 466104 463104 458103 453102 451102 451105
      452107 456110 461113 463119 464124 467129 469133 470139
      477144 484152 488154 492155 497149 500145 500141 485127
      479121 476118 475116 476114 478107 480104 484100 484093
      485085 484080 484072 484068 486066 491066 494064 501055
      504052 507048 508045 509037 511031 514027 519020 524011
      526005
 0.01 455850 454847 456845 454842 454840 452843 453845 451848
      449850 450853 451855 451857 453855 453852 455850 455850
 0.01 435030 435028 433023 434018 434016 432014 430014 427015
      423015 421015 421018 423020 425023 426025 430028 431028
      433030 435030
 0.01 428788 427784 427781 424782 422784 420785 419787 417790
      416793 416797 417802 418802 422801 423799 424796 425794
      426791 428788
 0.25 496249 497233 495228 491226 484231 476234 472234 470230
      472218 470215 464214 455214 451213 445213 437216 430219
      426221 424223 425225 426229 425232 422237 420242 422245
      425249 430252 441254 450254 458250 462249 467251 472253
      477253 481251 484248 488248 494250 496249
 0.25 510019 511011 509003 507998 503993 497985 493975 495959
      498947 497940 495934 492932 487932 479928 477929 476933
      475939 473955 469967 467979 466988 466996 471006 477014
      483023 487035 491035 496033 502027 510019
 0.25 378723 379717 377712 375710 370711 364715 356719 352721
      347721 340721 333726 328731 319744 315751 311758 304772
      300778 296784 289789 285794 289796 294796 296798 294801
      289815 285821 279823 274828 269835 265841 261848 260856
      261863 264872 268880 274894 277903 277908 277914 277929
      273937 271945 272954 275956 280957 285957 290958 295964
      306973 308974 313973 316971 319971 323966 329962 341952
      347946 353942 356940 359936 361929 368914 371906 374896
      379878 383861 385852 384843 376841 375837 375833 375827
      374821 371819 370816 370806 369801 367798 366793 364791
      359785 357781 357774 357764 359757 363750 373738 377729
      378723
 0.25 314998 314994 313991 312989 308988 304989 303992 302994
      301998 303000 304003 306005 309005 311003 313000 314998
 0.50 494241 494239 494238 493235 492235 491234 490234 489235
      489236 489239 490242 492243 493243 493242 494241
 0.50 504016 504011 503006 499000 496994 492989 488983 487975
      487958 484954 481959 479960 477965 475972 472979 471989
      473997 478002 487010 489019 489028 492028 495026 499021
      504016
 0.50 463223 463220 461218 456218 447217 442217 438218 432222
      430225 431231 434239 438242 443244 448245 452243 458237
      456234 453233 451233 451230 454225 458226 462225 463223
 0.50 366737 366732 363730 359727 349728 341730 334733 329738
      320746 317751 314757 309771 306778 304785 306789 305791
      303797 298809 296816 292822 275841 273847 271855 272861
      275869 281880 283898 284916 283925 280933 277939 275945
      277948 281949 288947 292950 295956 302956 308952 326934
      333924 337925 340927 336934 333939 332943 336944 342942
      348937 352932 354925 355921 358918 362913 365906 368899
      370893 371885 366871 364863 364854 366838 362823 362818
      361815 358808 356797 353789 353782 353773 354766 354757
      356752 361746 364742 366737
 1.00 352746 353742 351739 346738 335743 329746 324749 321753
      319759 315770 311784 309796 304808 303814 302820 300827
      298832 294836 289838 285838 282839 279845 278852 279856
      281857 286862 288867 291873 292880 292885 289891 287903
      288912 287921 283932 280937 280941 283942 292936 299927
      303922 304920 306923 306929 305935 302941 301946 305947
      307945 312941 319931 324922 330913 337902 345877 347865
      348858 348848 347839 346832 345824 344816 340804 340797
      341790 346763 352746
 1.00 319888 319885 319883 318881 318880 317881 316883 314883
      314884 313885 312886 311888 311890 313891 315890 316890
      318889 319888
 1.50 342757 342753 340752 334751 327753 324759 314782 314790
      314798 311805 310812 307823 304831 302836 292843 286845
      283848 283850 285855 289859 292864 295872 298878 302880
      305880 308878 312873 315868 317864 319864 323867 323874
      323881 321888 318894 313898 309901 304900 300897 296896
      293897 287927 285932 284936 287937 292933 295928 303919
      307915 313914 314916 314921 312927 308939 310939 311937
      315932 321920 325908 329902 331896 331884 336871 339858
      340853 338849 335843 334826 333810 331802 331794 334778
      339767 342757
 2.00 338762 337760 333759 331757 329759 327762 326764 329765
      329766 327769 328772 331770 333768 334767 337764 338762
 2.00 328777 328775 326771 323773 321776 320778 319780 317783
      317787 319790 321793 323794 324792 326789 327786 328783
      328779 328777
 2.00 328818 327808 324799 322796 318799 316806 312824 308832
      304838 290845 288849 289853 292856 293861 296869 301875
      306874 308871 312864 315856 317853 320849 322847 324843
      326834 328818
 2.00 324896 324894 322894 322896 322897 324896 324896
 2.00 318903 318900 317900 315900 313900 312901 311903 311905
      311906 312907 313908 315907 316907 317905 317904 318903
 2.00 306909 303905 298903 293906 292912 290918 289925 287931
      286933 288934 292930 295924 299920 303917 306911 306909
 3.00 319834 316834 313837 310840 307843 303844 298847 295849
      298852 304852 307850 310847 313843 315839 317836 319834
 3.00 296916 295914 293915 293916 293918 294918 295917 296916

$$





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