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Quantitative Precipitation Forecast (QPF) Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1853Z Mar 27, 2015)
 
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Abbreviations and acronyms used in this product
 
Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White


QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
253 PM EDT FRI MAR 27 2015


PRELIM DAY 1 QPF DISCUSSION
VALID MAR 28/0000 UTC THRU MAR 29/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

CENTRAL TO EASTERN LONG ISLAND/SOUTHERN NEW ENGLAND

HEIGHT FALLS ROTATING THROUGH THE BASE OF THE ELONGATED EASTERN
TROF TONIGHT AND OFFSHORE OF THE CAROLINAS BY EARLY SATURDAY WILL
INDUCE CYCLOGENESIS OFFSHORE OF THE NORTHERN MID
ATLANTIC/SOUTHEAST NEW ENGLAND SATURDAY.  THE DEVELOPING COMMA
HEAD/DEFORMATION PRECIPITATION BAND WILL AFFECT CENTRAL TO EASTERN
LONG ISLAND INTO SOUTHERN NEW ENGLAND WITH A RAIN TO SNOW
CHANGEOVER AND POSSIBLE ACCUMULATING SNOWFALL SATURDAY.  THE 0000
UTC ECMWF WAS A DRY OUTLIER WITH QPF AMOUNTS OVER THESE
AREAS--WITH A MAJORITY OF THE REMAINING GUIDANCE IN THE .10-.25"+
RANGE.  THE 1200 UTC ECMWF DID TREND WETTER ACROSS THIS
AREA---MUCH CLOSER TO THE NAM---GFS---SREF MEAN---1200 UKMET
CONSENSUS WHICH WAS FOLLOWED FOR THE DAY 1 QPF. 

MID ATLANTIC

FARTHER TO THE SOUTHWEST THRU THE MID ATLANTIC---LIGHTER
PRECIPITATION TOTALS POSSIBLE ACROSS MOST OF THE MID ATLANTIC FROM
PA INTO THE CAROLINAS AS THE STRONG UPPER TROF AXIS SWINGS
EASTWARD EARLY DAY 1.  NOT A LOT OF CONFIDENCE WITH QPF DETAILS
HERE.  THERE IS MODEL CONSENSUS FOR A SMALL AREA OF .10"+ PRECIP
TOTALS OVER SOUTH CENTRAL VIRGINIA.  HOWEVER--WITH THE SIZE OF THE
AREA SO SMALL AND NOT LOCKED TO TERRAIN---CONFIDENCE IS LOW.


LOWER MO VALLEY INTO THE LOWER MS VALLEY

ADDITIONAL HEIGHT FALLS DIVING SOUTHEASTWARD IN THE NORTHWESTERLY
MID TO UPPER LEVEL FLOW OVER THE MS VALLEY WILL ENHANCE UVVS ON
THE COLD SIDE OF THE SURFACE FRONTAL BOUNDARY STRETCHING FROM
NORTHWEST TO SOUTHEAST OVER THE PLAINS.  LIMITED MOISTURE AND THE
QUICK MOVEMENT OF THE ASSOCIATED SURFACE WAVE WILL KEEP PRECIP
TOTALS ON THE LIGHT SIDE ACROSS PORTIONS OF THE LOWER MO AND LOWER
MS VALLEY.

PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES

THERE IS GOOD MODEL AGREEMENT WITH THE INLAND MOVEMENT OF STRONG
NORTHEAST PACIFIC HEIGHT FALLS THROUGH THE PACIFIC NORTHWEST
TONIGHT AND INTO THE NORTHERN ROCKIES ON SATURDAY.  STRONG UVVS
AND ABOVE AVERAGE PW VALUES ALONG THE INLAND MOVING FRONT EARLY IN
THE PERIOD AND POST FRONTAL ONSHORE FLOW IN THE WAKE OF THE FRONT
WILL SUPPORT WIDESPREAD MODERATE TO LOCALLY HEAVY PRECIPITATION
TOTALS IN THE FAVORED TERRAIN AREAS FROM NORTHEAST
OREGON---NORTHEAST WASHINGTON STATE---NORTHERN ID AND NORTHWEST MT
AND FROM THE WA/NORTHERN OREGON CASCADES---WESTWARD TO THE
NORTHERN OREGON COAST RANGE INTO THE WASHINGTON COAST RANGE AND
OLYMPIC RANGE.  QPF DISTRIBUTIONS ARE FAIRLY SIMILAR WITH THE 12KM
OUTPUT FROM THE NAM USED PRIMARILY.

ORAVEC

GRAPHICS AVAILABLE ON THE WEB AT www.wpc.ncep.noaa.gov/qpf/qpf2.shtml

24HR QP VT 29/00Z
 0.01 454626 458631 460639 462643 460649 445672 440682 437688
      437692 438695 442696 446695 449694 451698 453699 456699
      460696 456710 451719 442728 437732 431736 429742 423744
      418745 413743 405744 402744 400742 396737 391740 383748
      376757 372763 376769 380774 381780 378785 376787 373788
      369786 365782 357775 350772 348771 346772 332775 322781
      316784 312780 308765 307757 308750 308743 309737 313724
      316719 320715 328707 337700 348693 360686 374683 378683
      383680 395672 397658 399650 401643
 0.01 539199 539192 538186 537179 535174 523157 517149 512136
      510120 512100 513083 515077 515067 515051 515036 516018
      513004 510001 506004 498011 495013 493015 493019 489032
      487038 486047 483059 476068 473072 470077 468083 466087
      462087 458084 454080 449073 443072 444075 447080 449085
      450088 449091 445093 442091 438093 435092 426087 424091
      426095 421105 421109 419114 415116 414120 418122 421126
      424129 426127 433116 437114 439117 442121 447131 449136
      449141 447145 442144 438146 434150 435154 440164 445171
      445176 443178 442178 440183 442190 439196 442200 447202
      450197 455195 458192 461191 463192 470194 474193 481190
      487191 491194 491198 489199 484201 475204 467207 461207
      457209 448211 438214 430216 426218 423221 426231 421233
      416232 410234 407239 402242 404246 409247 413247 424248
      435248 445251 455252 468256 474259 478263 485272 492280
      495284 501288 503290 505290 510289 514283 517276 520268
      524255 528236 530230 532222 534217 536210 539199
 0.01 477982 476977 473972 467966 457959 449956 429951 423942
      419940 416935 380916 374909 367904 359898 353890 347880
      341873 338869 333868 331866 327868 325872 324877 326882
      329885 331889 338897 345906 355922 361930 361934 359936
      357938 373950 374955 377961 388959 411959 415961 419966
      428971 433973 438974 447978 457982 465986 470986 472985
      476984 477982
 0.01 434782 434777 433772 431766 428764 425765 417768 412772
      409777 398788 386794 382795 381798 377805 372810 368815
      361818 358816 355812 351809 346807 339805 335804 333806
      331809 331812 334819 338824 345827 347827 349832 350840
      353842 355839 360834 367824 372819 375817 379816 389811
      407809 410808 413810 419807 424801 429798 433790 434782
 0.01 275791 274779 272775 269773 264773 260772 255772 251774
      239787 232802 226817 220833 220837 225837 228840 230844
      235844 238842 244837 254822 262807 273795 275791
 0.25 528202 527199 527198 526196 524194 523194 522195 521197
      522200 522201 523203 523204 525205 526205 527204 528202
      528202
 0.25 515269 517260 517252 513237 511231 508226 504221 502215
      498209 494206 489206 482206 462212 453216 442219 443223
      449226 454224 458227 458229 455233 450235 447236 447239
      452243 457243 463244 468244 474249 482257 486261 490267
      495277 499282 502284 506285 515269
 0.25 518182 518178 518175 516172 509166 504159 503147 489135
      486132 482130 474130 472133 471139 478144 478149 473149
      464145 461147 458150 456154 454159 457162 461163 467170
      483179 500187 505187 510190 514190 517185 518182
 0.25 489231 489228 487225 484224 481222 478221 474221 472221
      471226 473228 476230 478231 480234 482237 485235 487233
      489231
 0.25 464179 463176 462176 461176 459176 458177 457177 456178
      455179 454181 454184 455184 457185 458185 458184 460183
      462181 464179
 0.25 445654 438651 434650 429651 419658 411664 392696 383696
      378697 374699 365705 358710 342719 334725 327731 322739
      318746 316755 317763 320765 325766 328763 337759 354749
      369741 378736 386730 393724 396724 401724 410728 421724
      436715 436712 434711 431709 423704 421697 423691 428685
      433676 438668 445654
 0.25 251792 251788 248786 243789 240795 238799 236806 235812
      234818 236822 240817 243813 245808 247802 250797 251792
 0.50 513258 510238 501224 498216 496211 491210 483208 476210
      470213 463216 456218 456221 460225 465224 471219 474218
      478219 488223 490226 491230 495238 500245 503248 505252
      507261 510263 513260 513258
 0.50 505281 506277 506273 505266 500256 494248 492243 488239
      482239 479234 475232 472234 472239 473241 475245 481249
      486257 492266 497276 500280 503282 505281
 0.50 494174 496169 494166 490162 485157 479156 474153 469153
      466152 462153 465159 469164 474166 479170 483174 490176
      494174
 0.50 486136 484135 482135 484136 486136 486136
 0.50 426669 425667 424668 422670 420673 418675 414676 413678
      412682 412683 414685 416684 418681 420678 421675 423674
      425672 426669
 1.00 499271 499266 497262 495257 494253 491248 490244 486243
      487249 489252 490258 492262 495267 498270 499271
 1.00 500238 500235 500232 498231 498229 497227 497226 496224
      495223 494222 494223 494225 494227 495228 495231 495232
      496233 496234 498236 498237 499237 500238
 1.00 479241 479238 478235 477235 476234 474234 474236 474237
      475239 475240 477241 478241 479241