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 251858
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
157 PM EST WED FEB 25 2015


PRELIM DAY 1 QPF DISCUSSION
VALID FEB 26/0000 UTC THRU FEB 27/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...


...SOUTHEAST - MID ATLANTIC...

A VIGOROUS SOUTHERN STREAM SHORTWAVE OVER THE ARKLATEX EARLY THIS
AFTERNOON WILL FURTHER DEAMPLIFY AS IT PUSHES EAST INTO THE LOWER
MS VLY... THEN NORTHEAST ACROSS THE  MID ATLANTIC AS IT BECOMES
ABSORBED INTO THE FAST MID LEVEL FLOW (WHICH WILL BE AIDED BY THE
DIGGING LONGWAVE NORTHERN STREAM TROUGH). THE LONGWAVE TROUGH WILL
SPIN UP A SURFACE LOW ALONG THE LOW-LEVEL BAROCLINIC ZONE
STRETCHING ACROSS THE SOUTHEAST STATES. THE LOW TRACKS NORTHEAST
ALONG THE BOUNDARY TO A POSITION OFF THE MID ATLANTIC COAST BEFORE
EXITING THE REGION. IN TERMS OF THE 12Z MODELS...BOTH THE NAM AND
ECMWF HAVE SHIFTED THE SURFACE LOW TRACK A LITTLE MORE NW OFF THE
NC OUTER BANKS COMPARED TO THE PREVIOUS RUN. THE TREND IS
SUPPORTED BY THE UPSTREAM SATELLITE TRENDS WITH THE NORTHERN
EXTENT OF THE BAROCLINIC LEAF...ALONG WITH THE FACT THAT THE
NORTHERN STREAM SHORTWAVE CURRENTLY DIVING SE ACROSS THE NORTHERN
PLAINS WILL LIKELY ENSUE HEIGHT RISES WITH THE NORTHERN STREAM
ACROSS THE MID ATLANTIC AND NORTHEAST. ADJUSTMENTS TO THE DAY 1
QPF INCLUDE A NORTHWARD SHIFT OF THE .10 AND .25" QPF INTO THE
NORTHERN MID ATLANTIC REGION...PER A MULTI-MODEL CONSENSUS GIVEN
THE AFOREMENTIONED TRENDS...HOWEVER ONCE AGAIN FEEL THE NAM AND TO
A LESSER EXTENT THE LATEST ECMWF ARE A BIT TOO WET TOO FAR N INTO
THE COLDER LOWER LAYERS ACROSS E-NE NORTH CAROLINA AND SE
VIRGINIA. SNOW...SLEET...AND ICE WITH THIS STORM SYSTEM ARE
EXPECTED ACROSS A GOOD PORTION OF THE AREA. PLEASE REFER TO THE
LATEST SUITE OF WPC WINTER WEATHER PRODUCTS FOR MORE INFORMATION.


...MIDWEST...

THE AFOREMENTIONED UPPER LEVEL JET STREAK/SHORTWAVE ACROSS THE
NORTHERN PLAINS WILL DIVE SE INTO THE LONGWAVE TROUGH BASE OVER
THE MID MISSISSIPPI VALLEYST SPINS UP A SURFACE LOW THAT TRACKS
ALONG WITH THE SHORT WAVE...BEFORE BECOMING ABSORBED BY THE
LONGWAVE TROUGH. MODEL QPFS CONTINUE TO CONVERGE ON AMOUNTS OVER
THE MIDWEST...WITH A MULTI-MODEL CONSENSUS SUPPORTIVE OF A MAX
BETWEEN .25 AND .50 (AFTER 00Z 02/26) ACROSS NORTHEASTERN
MO/SOUTHEAST IA AND PORTIONS OF NORTHWEST IL.


SNOW IS EXPECTED WITH THIS SYSTEM. PLEASE REFER TO THE LATEST
SUITE OF WPC WINTER WEATHER PRODUCTS FOR MORE INFORMATION.


...CENTRAL/SOUTHERN ROCKIES...

A SHORT WAVE TRACKING FROM WESTERN CANADA ACROSS THE NORTHERN AND
CENTRAL ROCKIES PROVIDES SYNOPTIC SCALE LIFT ABOVE AN ARCTIC FRONT
BANKED UP AGAINST THE TERRAIN. THE COMBINATION OF THE LIFT AND
UPSLOPE FLOW IS EXPECTED TO PRODUCE AN AXIS OF QPF ACROSS THE
CENTRAL AND SOUTHERN ROCKIES. FOR THE MOST PART...THERE WAS DECENT
AGREEMENT WITH RESPECT TO THE TRACK OF THE SHORT WAVE AND THE
MAGNITUDE OF THE UPSLOPE...SO THE WPC QPF WAS BASED ON A BLEND OF
THE 00Z GFS/12Z ECMWF...WITH SOME 21Z SREF MEAN USED TO BETTER
DEPICT HIGHER TERRAIN QPF MAXIMA.

THE LIFT IS NOT OVERLY IMPRESSIVE WITH THE SHORT WAVE AS IT TRACKS
SOUTHEAST ALONG THE NORTHERN AND CENTRAL ROCKIES...BUT THE LIFT IS
AUGMENTED BY DIVERGENCE IN THE LEFT FRONT QUADRANT OF JET 90 KNOT
JET STREAK DIVING IN BEHIND THE SHORT WAVE. THE LIFT WILL NOT HAVE
MUCH MOISTURE TO TAP...AS PRECIPITABLE WATER VALUES IN THE COLUMN
GENERALLY REMAIN BELOW 0.25 INCHES. ACROSS THE NORTHERN
ROCKIES...THIS EQUATES TO A LARGE AREA OF 0.10 TO 0.25 INCHES QPF
EXTENDING FROM WESTERN MT THROUGH MUCH OF WY. AS AN ARCTIC FRONT
BECOMES BANKED UP AGAINST THE NORTHERN ROCKIES...THE UPSLOPE FLOW
AUGMENTS THE MOISTURE IN THE COLUMN...PRODUCING AXES OF 0.25 TO
0.50 INCHES OF QPF ACROSS THE ROCKY MOUNTAIN FRONT RANGE IN
MT...AS WELL AS THE GRAND TETONS AND BIG HORN RANGES IN WY.

FURTHER SOUTH...WHERE THE UPSLOPE FLOW BEHIND THE ARCTIC FRONT IS
STRONGER...THE AXIS OF 0.25 TO 0.50 INCHES OF QPF IS
WIDER...ENCOMPASSING MUCH OF THE ROCKIES OF CENTRAL CO INTO THE
SANGRE DE CRISTO MOUNTAINS OF NORTHERN NM. LOCAL 0.50 AMOUNTS ARE
EXPECTED IN THE HIGHER TERRAIN OF THE CO ROCKIES...WHERE THE
UPSLOPE FLOW IS FOCUSED.

SNOW IS EXPECTED THE HIGHER TERRAIN. PLEASE REFER TO THE LATEST
SUITE OF WPC WINTER WEATHER PRODUCTS FOR MORE INFORMATION.


...PACIFIC NORTHWEST INTO THE NORTHERN/CENTRAL GREAT BASIN...

SHORT WAVE ENERGY TRACKS SOUTHEAST ACROSS THE PACIFIC NORTHWEST
DURING DAY 1. THE SHORT WAVE PUSHES A PACIFIC FRONT ACROSS REGION
DURING THE SECOND HALF OF THE PERIOD...WHICH BECOMES THE FOCUS FOR
QPF. THERE WERE SOME MINOR TIMING DIFFERENCES AMONG THE 00Z MODEL
SUITE MEMBERS WITH RESPECT TO SHORT WAVE TIMING (WHICH IS TO BE
EXPECTED IN A FAST MID LEVEL FLOW)...SO THE WPC QPF WAS BASED ON A
BLEND OF THE 00Z GFS/12Z ECMWF...WITH SOME 21Z SREF MEAN USED TO
BETTER DEPICT HIGHER TERRAIN QPF MAXIMA.

AS A SHORT WAVE TRACKS SOUTHEAST INTO THE PACIFIC NORTHWEST DURING
THE SECOND HALF OF DAY 1...LIFT WITH THE SHORT WAVE IS AUGMENTED
BY DIVERGENCE IN THE LEFT FRONT QUADRANT OF A 110 KNOT JET STREAK
FOLLOWING ON ITS HEELS. THE LOW LEVEL FLOW AHEAD OF THE SHORT WAVE
USHERS IN PRECIPITABLE WATER VALUES NEAR 0.75 INCHES TO THE WA/OR
COASTLINES. THE LOW LEVEL FLOW FOCUSES THE MOISTURE IN THE HIGHER
TERRAIN...RESULTING IN STRIPES OF 0.25 TO 0.50 INCHES OF QPF
ACROSS THE NORTHERN OLYMPIC MOUNTAINS IN WA...AS WELL AS THE
CASCADES OF WA AND NORTHERN OR.


HURLEY


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

24HR QP VT 27/00Z
 0.01 321703 341673 362656 381655 394650 408647 414646 419647
      422648 427651 431655 433664 433670 432675 428688 426693
      424700 421706 420713 418719 416724 411734 400752 399759
      400767 406778 408782 407785 411786 414785 417783 420778
      423774 426773 427776 430778 435779 438787 437794 434802
      431808 430814 428818 426824 426828 429831 431833 429850
      428852 427857 426859 427863 433864 438863 443864 445865
      446868 445871 443871 438873 435875 434879 434888 431902
      430908 428915 425921 422926 415935 416940 416944 415945
      410943 405945 397951 380963 376965 373965 371963 370961
      369958 370954 371950 373945 376941 377937 374934 371934
      371930 371925 370922 365923 359923 357918 355915 353914
      349912 348910 347907 349901 354899 353897 350895 338893
      317886 306882 292883 284888 275894 267899 261901 255901
      250899 247895 245888 246879 238876 233865 235852 247826
      258805 279772 302737 312720 318711 321703
 0.01 520269 523244 524240 522235 521231 519225 514221 509215
      507207 506203 507198 512195 518198 522198 526198 526195
      526190 526183 522176 520173 518171 511167 495163 481155
      476149 480142 486144 488147 491149 501157 508160 511160
      514158 514155 512152 508145 503139 501136 497135 496132
      492130 486126 480122 471120 469121 467120 468117 472112
      474111 475105 475096 473087 470083 460089 456086 456081
      460079 463075 464070 462065 460059 455054 451046 448037
      444030 439029 432030 424029 408028 394028 391027 390025
      386019 384015 381012 372012 369012 366014 363016 360014
      345007 341001 339993 338986 337977 334970 332969 328971
      324975 323979 322983 324999 329014 331020 332031 331036
      328039 318038 313034 311032 307031 304032 304036 308041
      313045 318048 324052 326056 328058 337059 346060 353062
      358067 360068 365069 369070 371072 373082 376090 376098
      379099 381097 387093 394098 396104 395109 393111 386115
      382115 380116 377119 376123 375126 374132 373137 375140
      376137 377132 378129 384123 388123 391121 396123 400125
      405128 409129 410134 410137 408141 401143 398140 394139
      390139 388141 388150 390156 393161 397167 402172 407175
      413180 416182 417186 418194 421199 423202 428206 434209
      439210 442209 444212 442215 438216 436218 432221 431226
      432229 433233 431235 417235 415238 414244 417251 421258
      427263 438275 449284 462291 468296 476299 484302 490300
      496300 499299 501297 503295 506296 509294 510291 515278
      520269
 0.01 491196 492190 491184 483181 476179 473178 471183 466189
      462194 457199 461206 468207 474204 480202 484202 487200
      491196
 0.01 462119 461115 457113 452118 448119 446117 442116 440113
      435113 433116 429123 427126 426132 428135 432137 438134
      442133 444128 448123 451122 455122 459122 462119 462119
 0.01 448143 448141 447141 446138 444138 444137 443135 441137
      440139 441140 442142 442143 443144 444146 445145 447145
      448143
 0.01 450088 449083 447080 444077 439074 437075 436078 434076
      431074 427077 427081 428084 430087 432089 435088 438088
      442091 447092 449090 450088 450088
 0.01 422098 420095 419095 417095 415095 414097 413097 412099
      412101 413102 414103 416104 418102 420100 422098
 0.01 408091 408089 407087 407086 405085 404086 404088 405090
      405091 407092 408091
 0.01 401816 401813 399813 396814 392820 387827 382832 377837
      375844 373853 373858 372862 368880 365887 368890 370889
      376884 380877 382870 383861 386852 387849 390845 397843
      398834 399828 399823 401816
 0.25 501272 501265 498260 494251 491245 488241 484242 482241
      480235 476232 472233 469235 468239 469241 474244 478246
      483246 486250 489255 494264 497270 501272 501272
 0.25 502238 500229 497221 488210 483208 479207 474209 468213
      461215 449217 442220 443224 446226 453227 457228 459230
      463231 466229 470223 476221 478220 483221 487221 491223
      494230 497237 500239 502238
 0.25 466237 465236 464235 462233 460233 459232 457232 455233
      453234 452235 452237 453239 454240 456241 457241 459242
      461241 462241 463240 464239 465237 466237
 0.25 462181 463176 462173 458173 455172 453169 450169 448173
      449177 447181 441183 441188 444190 446189 451191 455187
      458184 462181
 0.25 413675 413672 412669 408668 402669 396672 393674 390672
      383667 380666 375667 368668 359673 351679 348682 345684
      339693 331708 323721 314736 304752 300759 295766 285780
      277794 265828 262835 257842 254845 253850 257850 260848
      265841 267833 276820 280813 285806 294792 300786 303785
      307785 305794 304805 300813 294820 289824 284831 283840
      276848 272853 271857 274859 276867 280867 286866 300860
      307856 312854 318853 326853 334857 340858 345857 350855
      353852 357845 361838 365829 370820 372812 373807 376803
      380794 380782 384774 386765 387755 390744 394724 399705
      400695 403687 406683 410681 413675
 0.25 413898 411891 409889 407891 404894 401901 398908 394911
      392913 391917 392923 394927 396929 400931 404929 406926
      409919 412910 413901 413898
 0.25 409066 408054 403047 397041 388038 380034 371032 362028
      355025 351022 346021 343023 343026 343033 344037 347048
      359059 364061 367063 370066 375068 376065 375063 373061
      377059 382060 400066 406068 409066
 0.50 481213 480213 479212 477212 476212 477214 479213 480213
      481213
 0.50 390702 389694 387688 385684 380683 369685 359690 350696
      343703 334719 327728 322736 313753 310763 317761 319761
      320766 316776 313786 311791 310798 310803 310810 306818
      301828 298832 297836 295841 297845 301848 305848 316846
      326842 333839 338836 342833 349825 354817 358809 364800
      371780 374769 377760 381748 384738 387728 389716 390702
 0.50 400051 388048 380043 375041 371042 367043 364041 360039
      351035 350037 351041 353045 355050 358054 362056 368057
      376053 382053 388053 397053 400051
 0.50 308767 301768 298771 295776 292782 290787 287791 288794
      289792 293787 296783 300779 304774 306769 308767
 0.50 282804 282802 281801 279802 279803 279805 280806 281804
      282804
 1.00 376717 374708 370702 365700 358703 352707 348712 345717
      342724 338737 333750 328762 324775 319806 317813 314819
      316822 322826 324827 327826 331821 339811 346800 354790
      360778 362771 363764 364756 367748 371736 374725 376717
 1.50 359736 358730 356728 353728 350731 342742 338749 335755
      329769 331784 332794 332802 337799 341795 347780 349772
      352765 354757 355748 359736

$$




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