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 151900
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EDT WED APR 15 2015


PRELIM DAY 1 QPF DISCUSSION
VALID APR 16/0000 UTC THRU APR 17/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

...ROCKIES AND HIGH PLAINS..

SYNOPTICALLY IT IS A STRAIGHT-FORWARD FORECAST ON DAY 1 WITH
STRONG UPPER DIFLUENCE...FRONTAL FORCING...AND LOW LEVEL UPSLOPE
FAVORING MUCH OF CENTRAL AND SOUTHEAST WYOMING AND FAR NORTHERN
COLORADO FOR THE GREATEST SNOW AND LIQUID PRECIPITATION
AMOUNTS...TO THE NNE OF THE TRACK OF A CLOSED MID LEVEL LOW
CENTER. SOME SOLUTIONS SUCH AS THE 00Z ECMWF DISPLACED OR
STRETCHED A QPF MAXIMUM FARTHER NORTH AND EAST INTO NE/SD. WE KEPT
THE HEAVIER AMOUNTS CONFINED TO THE POST-FRONTAL UPSLOPE AREAS
FARTHER WEST IN THE NE PANHANDLE AND EASTERN WYOMING...USING A
BLEND OF PREVIOUS WPC WITH OUR IN-HOUSE ENSEMBLE AND THE GFS.
COMPARED TO THE PREVIOUS FORECAST WE TRENDED SLIGHTLY HEAVIER IN
WY/NRN CO AND SLIGHTLY DRIER IN SRN UT/CO WHERE WESTERLY FLOW WILL
PERSIST SOUTH OF THE LOW CENTER. THE STORM OVERALL WAS NOT DRAWING
UPON ANY REMARKABLE MOISTURE FEED...BUT STRONG FORCING WILL
COMPENSATE TO PRODUCE GENEROUS PRECIPITATION...WITH LIQUID
EQUIVALENT AMOUNTS OF 0.25 INCHES IN NORTHERN COLORADO AND BETWEEN
0.50 AND 1.0 INCHES IN SE WY/FAR WRN NE THROUGH 17/00Z.

WE ALSO ATTEMPTED TO SHOW MORE OF A BREAK IN THE AMOUNTS ACROSS NW
KS AND CENTRAL NE...FOCUSING ON THE POST FRONTAL EVENT FARTHER
WEST AND THE WARM ADVECTION TONIGHT AND THEN STRONGLY FORCED
CONVECTIVE EVENT FARTHER ALL OCCURRING A LITTLE FARTHER SOUTH AND
EAST.


...GULF COAST STATES...

AHEAD OF THE WESTERN U.S. CLOSED LOW A ZONE OF MODERATE WEST TO
SOUTHWESTERLY UPPER FLOW AND COINCIDENT MOIST GULF AIR MASS WILL
PERSIST FROM TEXAS TO FLORIDA. TODAY CONVECTION SHOULD BE MORE
LOOSELY ORGANIZED THAN IN PREVIOUS DAYS...WITH DRY AIR HAVING
TEMPORARILY SURGED INTO SOUTHEAST TX AND SOUTHWEST LA...AND WITH
ANY DISCERNABLE SHORTWAVE TROUGHS REMAINING PRIMARILY OVER THE
GULF. SEA BREEZE ACTIVITY WILL PRODUCE BRIEF BUT LOCALLY HEAVY
DOWNPOURS ALONG THE CENTRAL GULF COAST. BY THURSDAY MORNING
EMPHASIS SHIFTS BACK TO THE WEST AS A WARM ADVECTION REGIME SETS
UP OVER TX/LA IN ADVANCE OF THE DIGGING WESTERN U.S. TROUGH.
MODELS HAVE BEEN TRENDING NORTHWARD WITH AN AXIS OF MODERATE TO
HEAVY RAINFALL PREDICTED FROM SOUTH TX TO SOUTHERN AL AND THE FL
PANHANDLE. A BETTER DEFINED MID LEVEL SHORTWAVE IS PREDICTED TO
CONTRIBUTE TO ORGANIZATION OF THIS RAINFALL OVER LOUISIANA IN
PARTICULAR. IT WAS THERE THAT WE HAD THE GREATEST CONFIDENCE TO
PLACE SOME HEAVIER AMOUNTS...AREAL AVERAGE 1-2 INCHES THROUGH
THURSDAY AFTERNOON. CONVECTION INITIATING WITHIN WARM ADVECTION
ALONG THE TX/LA COAST EARLY IN THE DAY MAY GROW UPSCALE AND MOVE
ESE. WE WERE LESS CONFIDENT FARTHER DOWNSTREAM OWING TO RELATIVELY
WEAK LOW LEVEL INFLOW WHICH MAY ENCOURAGE MORE OUTFLOW DOMINANCE
AND SPREADING OF THE HEAVIEST CONVECTION INTO THE GULF RATHER THAN
INLAND AREAS OF MS/AL. WE UNDERCUT SOME OF THE HEAVIER GUIDANCE
THERE...PREFERRING THE MORE CONSERVATIVE 09Z SREF MEAN. BACK OVER
CENTRAL TEXAS THE DETAILS ARE ALSO HARD TO DISCERN...BUT THE WAVE
ALONG THE LA COAST SHOULD NOT BE SO STRONG AS TO AFFECT THE CHANCE
OF ORGANIZED PRECIPITATION OVER THE TX HILL COUNTRY...AS
MOISTURE/INSTABILITY INCREASE BENEATH ENERGETIC AND BROADLY
DIFLUENT MID LEVEL FLOW. WPC QPF IN THIS REGION WAS SPATIALLY
SIMILAR TO OUR IN-HOUSE ENSEMBLE...BUT MORE CONSERVATIVE ON
AMOUNTS...AND KEEPING WITH CONTINUITY.


...CAROLINAS AND TENNESSEE / OHIO VALLEYS...

A FOCUSED CONVECTIVE EVENT WILL BE SQUEEZED BETWEEN A SINKING
FRONTAL BOUNDARY AND APPROACHING MID LEVEL SHORTWAVE OVER SC/ERN
GA/NRN FL THROUGH THIS EVENING. IN AREAS NORTH OF THE FRONT THE
MID LEVEL WAVE WILL PUSH LIGHT TO MODERATE RAIN THROUGH NC/VA.
FARTHER WEST PRECIPITATION WAS FRACTURED AS OF WED AFTERNOON
WITHIN A ZONE OF WEAK BUT STEADY WARM ADVECTION OVER TN/KY.
PRECIPITATION WILL REMAIN ROOTED ABOVE THE SURFACE...AND LITTLE
INSTABILITY WILL DEVELOP...EXCEPT CLOSER TO A SURFACE FRONT DRAPED
ACROSS SOUTHERN TN. INSTABILITY...AND HEAVIER PRECIPITATION WILL
BE MORE LIKELY ACROSS CENTRAL AND WESTERN TN/KY BY THURSDAY AS A
WEAK WAVE FORMS ALONG THE SURFACE BOUNDARY. FARTHER NORTH...A
NORTHERN STREAM TROUGH DIPPING INTO THE GREAT LAKES WILL GRADUALLY
DRAG MOISTURE NORTH AND EASTWARD. LIGHT PRECIPITATION IS LIKELY TO
FALL OUT OVER A BROAD AREA EXTENDING INTO THE OHIO VALLEY AND
EASTERN GREAT LAKES THROUGH THURSDAY...BUT THE MODEL SIGNAL FOR
SIGNIFICANT AMOUNTS IS HARD TO FIND. WE REMAINED ON THE
CONSERVATIVE SIDE.

BURKE

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

24HR QP VT 17/00Z
 0.01 537213 538204 538197 537189 535184 530175 527169 523165
      520161 516161 508164 507173 508177 510185 512189 516201
      519212 523217 528219 533219 536215 537213
 0.01 524260 521252 517244 515240 514235 511232 507230 504221
      501219 497218 493217 492224 494233 497242 497247 495244
      489238 486238 483240 481259 482265 483270 481283 481288
      483292 486295 490297 493299 506297 517285 524260
 0.01 482055 482050 477049 473048 470046 469040 472035 476025
      478019 478013 478007 477004 473004 469006 466009 461010
      455014 452016 446017 444013 445008 446002 445996 445990
      443988 438983 433978 426975 421973 419970 414966 406961
      402959 399960 393964 387965 384967 369975 365977 359978
      350979 339979 335978 332977 328975 326972 324965 325956
      326943 327933 328922 330911 333901 337900 341902 343907
      348909 353909 358908 364903 376894 393888 396886 401886
      409885 418884 422883 439870 445862 443852 441847 445840
      447837 453829 449818 433804 424801 400789 381788 375793
      369792 367786 362775 358763 349740 346736 342728 340726
      337726 329729 323734 315739 309743 302751 297757 295765
      297771 298774 297777 285787 274796 261804 257811 263823
      281843 276859 265887 261920 266962 264976 264979 265984
      267987 270990 278995 276999 277002 280011 280016 283021
      286023 290025 300026 303027 306026 307023 306019 310014
      314011 319012 322014 327015 336019 339024 344023 348026
      355031 358033 360038 360049 365068 367073 367077 368081
      366085 365090 362093 359094 357098 356100 361101 363104
      364108 367118 368124 371127 375130 379132 386134 390133
      393130 402132 408131 416125 422121 426117 428113 430109
      433107 440106 444105 449105 454105 455101 463084 467076
      472069 478062 482055
 0.01 345831 341827 337823 332821 325822 322825 317830 318838
      321844 327842 334840 339838 342834 345831
 0.01 265017 266012 264009 262002 259994 255989 252987 248987
      243992 241995 241000 243007 247014 250015 253014 261015
      265017
 0.25 531208 532206 533203 533200 532198 532197 531196 529195
      528196 527197 526198 525199 525201 525203 525204 525206
      526208 527209 527210 529210 531208 531208
 0.25 518271 518262 516257 512244 507238 503234 500235 499240
      501247 502251 500255 496251 491246 488247 488265 489273
      491279 499287 503288 509286 512282 515277 518271
 0.25 446053 448042 447036 445034 440029 437024 430013 428006
      425999 423990 421987 417984 416990 418994 419003 416007
      407013 405023 403033 396043 393049 390057 391062 395062
      399067 400072 399074 397078 396082 396092 400095 403102
      406108 410109 413108 414106 416100 417089 419087 421088
      426092 429094 432091 434087 433083 435077 438071 443062
      446053
 0.25 410850 406843 401837 396831 390828 382827 376830 369842
      366849 364859 361862 357861 351862 344863 335863 328862
      322862 319860 315854 311846 310835 307828 302822 297818
      291815 284814 278813 276817 278820 287823 292826 295831
      299837 300841 301846 298856 295862 292865 287866 280869
      277876 271887 268896 268903 273906 277915 280923 281931
      277947 277955 277965 278974 283980 290985 294989 297992
      301992 305993 308995 311997 316997 317994 318990 314972
      312962 313956 317937 320922 321912 323898 328887 334885
      339884 346886 353884 356881 360879 363878 366874 368871
      372871 386871 395869 401865 405862 408857 410850
 0.25 399007 401002 400996 399990 399987 397984 391983 384984
      378987 367992 355997 344003 343007 345009 352011 359012
      365011 372009 378008 384009 390012 394012 396010 399007
 0.25 350773 346757 344749 341744 334742 326742 319746 314750
      306760 305763 305767 306774 305781 306788 311791 318790
      325788 332785 344783 349778 350773
 0.25 289014 290012 291010 290008 289006 287005 286006 285007
      285008 285010 285011 286012 287014 289015 289014
 0.25 255008 255006 256004 256002 255000 255999 254998 253997
      252996 251995 250996 249997 249998 249000 249001 250002
      251004 252006 253007 254008 255008
 0.50 515269 516262 515258 511249 508245 504244 505257 504261
      499259 494252 492251 490254 490265 492271 493275 499282
      504285 507283 512274 515269
 0.50 437052 439038 436033 431028 428025 421022 416025 414027
      414031 413037 410040 405044 402049 403056 405061 412071
      417075 423077 427077 431072 434066 436059 437052
 0.50 398851 398846 397842 394837 389833 384832 380833 377834
      374839 372846 373851 376852 381853 387854 394854 398851
 0.50 391997 392995 391993 391991 390990 389988 387987 385988
      384989 382990 382991 380992 380994 380995 381997 382998
      383999 385000 387001 389001 390000 390999 391997
 0.50 341764 341757 339751 335747 332746 327747 324747 318755
      312763 309768 309773 309784 311786 314786 318784 326779
      335773 339769 341764 341764
 0.50 324879 324875 323871 319867 314866 308867 307872 303876
      296883 288890 284894 283900 284914 288927 285941 286956
      284962 285965 288964 291965 294966 296968 295972 296978
      300983 302980 302977 302969 301964 302957 305954 314931
      314924 314916 314908 314901 316894 318890 323881 324879
 0.50 305831 304829 303827 302826 301825 300824 299823 298823
      296822 295824 296826 296827 297828 298830 300832 302833
      304833 305831
 1.00 513263 512261 512260 511259 510257 510256 509257 509259
      509260 510262 510263 512265 513263
 1.00 505279 505276 504271 503268 502266 500264 497262 495259
      494259 493264 494267 495270 497273 499275 500277 503280
      505279
 1.00 421048 421046 420044 419046 419048 420048 421048
 1.00 306922 306916 305907 304899 300895 293897 290902 289908
      290914 292920 293929 294931 297932 304931 306924 306922
 1.50 502273 502272 501269 500269 500272 501272 502273 502273
 1.50 303916 302914 301910 299907 297906 294908 293910 293914
      294916 295920 295922 297926 298926 301925 302922 303918
      303916

$$




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