Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center

 
 

 

Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Air Quality
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings

Satellite and Radar Imagery
   Satellite Images
   National Radar
Product Archive
WPC Verification
   QPF
   Medium Range
   Model Diagnostics
   Event Reviews
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   Staff
   WPC History
   Accomplishments
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.
 
Quantitative Precipitation Forecast (QPF) Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1853Z Sep 29, 2014)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
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 MON SEP 29 2014


PRELIM DAY 1 QPF DISCUSSION
VALID SEP 30/0000 UTC THRU OCT 01/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...INTERMOUNTAIN WEST OUT INTO THE CENTRAL/NORTHERN HIGH PLAINS...

THE CLOSED MID/UPPER LEVEL LOW CURRENTLY ACROSS THE GREAT BASIN
WILL FINALLY LIFT E THEN NE INTO THE NORTHERN PLAINS BY THE END OF
THE PERIOD AS ANOTHER SHORTWAVE TROUGH AND ASSOCIATED UPPER JET
STREAK DROPS INTO THE PAC NW AND NORTHERN INTERMOUNTAIN WEST.
THESE TROUGHS WILL EVENTUALLY PHASE...THOUGH NOT DURING THE DAY 1
PERIOD (THROUGH 00Z WED)...HOWEVER THE APPROACHING UPSTREAM JET
AXIS/SHORTWAVE TROUGH WILL CAUSE THE LEAD TROUGH TO TAKE ON A
NEGATIVE TILT UPON LIFTING OUT INTO THE CENTRAL/NORTHERN PLAINS ON
TUESDAY. STRENGTHENING DYNAMICAL SUPPORT WILL SPREAD INTO THE
FOOTHILLS AND EVENTUALLY CEN/NRN PLAINS DURING THE PERIOD...WITH
THE INCREASINGLY NEGATIVE TILT TO THE TROUGH LEADING TO STRONGER
UPPER LEVEL DIFFLUENCE/DIVERGENCE AND DEEP LAYER QVECTOR
CONVERGENCE. THE MODELS AGAIN SHOW THE UPPER DIVERGENCE MAXIMIZING
OVERNIGHT OVER THE WY/NORTHERN CO FOOTHILLS AND INTO THE NORTHERN
HIGH PLAINS...AS AN UPPER LEVEL JET STREAK ROUNDS THE TROUGH BASE
(ENHANCED LEFT EXIT REGION FORCING AND MORE ROBUST DEEP-LAYER
ASCENT). AT LOW LEVELS...THE PRE-TROUGH THERMODYNAMIC ENVIRONMENT
BECOMES INCREASINGLY FAVORABLE GIVEN THE INCREASING S-SE LOW-LEVEL
AGEOSTROPHIC RESPONSE...THOUGH THE AXIS OF HIGHEST PWS (ABOVE 1.25
INCHES) ALONG A 40-50 KT LOW LEVEL JET SHIFTS FARTHER EAST ACROSS
THE CEN/NRN PLAINS WHILE BECOMING MORE DISPLACED WITH THE BEST
UVVS/UPPER DIVERGENCE OVER THE FOOTHILLS AND HIGH PLAINS. AS A
RESULT...MODEL PROJECTED MUCAPES WITHIN THE AXIS OF BEST DYNAMICAL
FORCING (AND ANOMALOUS EASTERLY/UPSLOPE LOW-LEVEL FLOW) ARE
GENERALLY BELOW 500 J/KG...THEREFORE THE EXCESSIVE RAINFALL
POTENTIAL (SHORT TERM RAINFALL RATES) WILL BE LIMITED. AT THE SAME
TIME...THE AFOREMENTIONED ANOMALOUS EASTERLY COMPONENT (NEGATIVE
850 MB U WIND COMPONENT BTWN 4-5 STANDARD DEVIATIONS) ACROSS THE
WY/NORTHERN CO FOOTHILLS AND NORTHERN HIGH PLAINS WILL AGAIN FAVOR
MAXIMUM TERRAIN- ENHANCED RAINFALL TOTALS (AREAL-AVERAGE AMOUNTS
BETWEEN 1-3 INCHES)...EVEN THOUGH THE EXCESSIVE RAINFALL POTENTIAL
WILL BE MITIGATED BY THE LACK (ABSENCE) OF DEEP LAYER INSTABILITY.


...SOUTHEASTERN STATES...

EXPECT AREAS OF MODERATE TO HEAVY RAINFALL TO CONTINUE INTO THE
EVENING HOURS OVER THIS REGION AS THE UPPER TROUGH -- CURRENTLY
PUSHING THROUGH THE TN VALLEY -- CONTINUES TO PRESS EASTWARD. 
ANOTHER 3-6 HOURS OF FAVORABLE DYNAMICAL SUPPORT (UPPER LEVEL
DIVERGENCE AND MORE FOCUSED SOUTHERLY LOW-LEVEL MOISTURE
CONVERGENCE) AHEAD OF THE SHORTWAVE TROUGH WILL MAINTAIN THE
WIDESPREAD WARM-TOPPED CONVECTION...WHILE THE BACK EDGE OF THE
HEAVIER RAINFALL GRADUALLY PUSHES EAST. AS NOTED EARLIER...MAXIMUM
OBSERVED RAINFALL REPORTS (2-4+ INCHES) REMAIN HIGHER THAN THE
RADAR ESTIMATES...INDICATIVE OF THE EFFICIENT WARM RAIN PROCESSES
WITH THE DEEP WARM CLOUD LAYER (WET BULB ZERO HEIGHTS ~14000 FT OR
HIGHER) AND HIGH PWS (AOA 2.25 INCHES PER THE 12Z KCHS RAOB AND
LATEST GPS DATA). CONTINUE TO EXPECT THE WIDESPREAD CLOUD
COVER/LACK OF DIFFERENTIAL HEATING AND WEAK/MOIST ADIABATIC LAPSE
RATES ALOFT TO LIMIT THE RAINFALL RATES IN AREAS FARTHER NORTH OF
THE WARM/STATIONARY FRONT...HOWEVER HIGHER MUCAPES (~1000 J/KG)
ALONG AND SOUTH OF THE SFC FRONTAL BNDRY CURRENTLY ACROSS NRN FL
(NEAR THE SE GA BORDER) WILL ENHANCE THE EXCESSIVE RAINFALL
POTENTIAL ACROSS SE GA/NRN FL...WHILE ALSO INTO EASTERN PORTIONS
OF THE FL PENINSULA GIVEN THE ENHANCED MOISTURE CONVERGENCE VIA
THE EAST COAST SEA BREEZE COMPONENT. WPC CONTINUED TO LEAN MORE
CLOSELY TO THE HIGHER RESOLUTION GUIDANCE IN TERMS OF TIMING AND
LOCATION OF HEAVIEST RAIN...AS ADDITIONAL AREAL-AVERAGE AMOUNTS
ARE EXPECTED TO RANGE BETWEEN 1-2+ INCHES FROM SE GA INTO MUCH OF
THE FL PENINSULA...THE BULK OF WHICH WILL OCCUR PRIOR TO 00Z. PER
THE HIGH RES GUIDANCE...ADDITIONAL LOCALIZED AMOUNTS OF 3-4+
INCHES ARE EXPECTED.


...GREAT LAKES INTO THE NORTHEAST...

THE DIGGING H5 S/WV NOW VICINITY OF THE UPPER GREAT LAKES REGION
WILL PUSH A COLD FRONT RATHER QUICKLY THROUGH THE GREAT LAKES BY
LATER TONIGHT...AND INTO THE NORTHEAST ON TUESDAY. THIS NORTHERN
STREAM TROUGH WILL TRIGGER GENERALLY LIGHT-MODERATE SHOWERS WITH A
SYSTEM THAT WILL BE FAST MOVING AND ACCOMPANIED BY PWS TOPPING
AROUND 1.25 INCHES VICINITY OF THE FRONT.  MODEL QPFS WERE IN GOOD
AGREEMENT ON SOME 0.25-0.50 INCH RAINFALL AMOUNTS GRAZING THE
NORTHEASTERN LAKES AND STAYED CLOSE TO THIS SOLUTION.

HURLEY


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

24HR QP VT 01/00Z
 0.01 541192 542185 542178 541172 539167 537159 533151 529144
      524138 512128 508126 506124 496122 480124 470122 467119
      467116 469115 474113 476109 475104 472103 468105 464106
      462102 458096 456086 453077 453071 455065 462064 471064
      488062 496060 504056 517052 523047 528042 530037 529031
      528026 525023 521017 514014 501008 496001 492992 483978
      473966 467959 461952 455947 452940 449935 445932 440928
      436928 437931 441938 425936 417937 410942 397950 385961
      379966 371972 366976 360982 355989 350995 345001 340006
      334010 329016 327023 333026 330029 326031 319035 313040
      309047 307052 305057 304061 304067 307073 313075 317073
      321070 326066 337056 343052 351050 366047 382046 388046
      392048 395051 396054 395057 389063 385065 380064 376064
      373066 373068 376073 378076 377081 377085 379083 385079
      387077 389079 391083 393085 397085 402086 403090 405094
      406099 403110 397115 397120 401122 402126 402132 405142
      409159 416163 421162 422157 423150 423142 424136 426130
      430124 435126 437129 435147 433164 438169 444171 444174
      442176 441181 439185 438192 440195 443196 446193 453188
      459183 466180 473177 480183 486188 488191 488196 487200
      484203 478205 471208 465211 452215 445216 441216 438218
      436223 434225 436232 433233 430236 431242 434245 438245
      443245 450243 465242 473245 478246 481249 486256 489258
      492256 499253 503247 504237 505226 505218 508214 514209
      518209 521211 526212 530210 537203 540196 541192
 0.01 497737 496723 494710 493697 490688 488678 484670 481664
      478661 475661 473660 471662 467669 466679 467686 467691
      465735 464747 462755 455769 453777 449782 445784 442784
      436781 433780 428780 422777 420776 421773 425771 434769
      440765 445759 448752 450748 450743 445735 440732 437731
      432732 426735 418738 411739 405742 399747 395746 394745
      389745 386747 379752 374757 362767 350777 345778 341777
      340772 342770 346765 353760 358756 362751 371740 375734
      375729 375724 373720 370720 367718 362719 353721 346725
      333734 326740 321744 316749 311754 291773 286778 283783
      282786 278788 268788 260787 256788 253790 249793 248798
      248802 250805 255811 260816 261819 259821 262827 265834
      266836 266841 264847 261854 258862 259870 261876 265882
      267884 272884 274883 277880 280878 282874 286864 296855
      300853 303846 312835 320824 326812 335801 348791 357788
      363783 375772 378768 384763 390758 394753 398754 400757
      404762 404766 401769 395774 385786 381792 384795 387797
      385815 388826 391835 393843 397850 405842 407839 408843
      409854 411864 412868 415872 417875 419879 420891 423893
      426893 429893 431890 434882 436871 441851 443845 444841
      448839 451840 454840 456837 454834 453831 455828 460825
      468820 473814 478808 482800 488785 490777 493767 494760
      495752 497737
 0.01 428242 427240 426238 425238 423237 421237 419236 418236
      416235 414235 413236 414237 415239 417240 418239 419239
      421239 423240 424240 425242 426243 427243 428242
 0.01 447087 447079 446072 445066 443063 440062 430059 426058
      423060 418063 415066 415073 415078 412083 411088 412092
      412097 414103 418106 423105 427102 430097 434095 440095
      444093 447087
 0.01 427688 425684 421684 415690 409697 405705 402715 402720
      403727 407727 409723 414715 418707 422699 426691 427688
 0.01 376053 376051 372050 370050 367052 363052 361054 358053
      356055 356058 357058 361058 363058 366057 368057 372055
      374053 376053
 0.01 309933 309924 308918 303905 297895 293891 291891 289893
      287897 287906 291918 293924 293933 294949 295956 297956
      299954 303943 309933
 0.01 283080 284073 284070 282069 279065 275063 267056 262054
      256053 249053 244054 239056 236059 235063 237067 240071
      245073 254078 264081 277082 281082 283080
 0.25 536193 537182 534174 532170 529167 524163 518162 515165
      514171 514179 515182 518185 518191 522197 526201 528202
      531201 534199 536193
 0.25 504199 503197 501196 499196 498196 497198 496200 497202
      499203 500203 502202 502201 504199
 0.25 507159 507151 503145 499144 495148 492154 488157 484161
      484171 487175 492176 497172 500167 504163 507159
 0.25 492222 492217 490215 487213 484212 481212 478213 475214
      473216 474220 478221 481222 484223 486223 489222 492222
 0.25 507040 509033 507029 504024 495015 473001 467999 462996
      458989 456982 453974 450967 447960 443956 437953 431951
      425948 420946 413949 408952 403956 401959 402963 403967
      405968 410967 416968 422972 433977 445985 450989 455993
      445000 441001 437000 433000 429002 426006 419006 412004
      406005 399007 393008 379011 368017 357023 348030 339036
      336040 337043 341044 344043 358040 369035 375033 380033
      389033 396035 407042 412047 417050 432052 446056 459056
      472055 485053 492051 497049 503044 507040
 0.25 476139 475138 474137 472138 473141 475140 476139
 0.25 472153 471150 470148 469145 466143 463142 461144 459147
      458150 460152 462154 464156 467157 468157 471155 472153
 0.25 476787 476777 473773 468774 463779 457788 452792 446795
      439795 432796 426796 420795 413798 410801 407807 408817
      409822 411821 414818 417818 417823 417830 415837 415846
      416850 419850 423844 432819 437816 439817 435830 437834
      439832 443827 451821 460813 469804 474797 476787
 0.25 444113 444111 443111 442113 443114 444113
 0.25 429755 428750 426748 424746 422745 420744 416745 415746
      413748 414750 417752 419754 421756 423758 425759 428757
      429755
 0.25 407794 407793 406792 405792 404792 404793 402795 402796
      402797 404799 406798 407796 407795 407794
 0.25 404977 403976 401976 400975 398975 396975 394975 393976
      391977 390979 390981 390984 391984 392985 394985 396984
      398983 400982 401980 402979 403978 404977
 0.25 387974 386972 385972 384972 382973 381974 380976 379977
      378978 378979 377980 376981 376983 377984 378983 380983
      382982 384981 384979 385977 386976 387974
 0.25 347747 345745 342746 336748 326755 320760 316764 306774
      289793 284794 277794 271793 262793 258794 255796 255799
      255802 260807 264811 269815 273820 276826 273829 272832
      276837 280837 282835 286829 291825 301817 304819 308819
      312815 319804 325792 336768 343757 345752 347747
 0.25 268068 266064 263062 259061 253061 250061 244061 242063
      244065 247067 253068 258068 260068 265069 268068
 0.50 529180 529179 529178 528176 527177 526179 526180 527183
      529181 529180
 0.50 502036 503031 501028 497024 492020 486017 478010 472007
      466006 459005 454006 440007 431014 423014 417013 411012
      407014 393016 388020 387023 388025 396027 401030 409038
      414043 419046 433049 446052 453053 460053 473052 485050
      491048 495046 500041 502036
 0.50 418954 419952 417950 416951 414951 413952 412952 410954
      409956 410958 412958 414958 415956 416956 417955 418954
 0.50 371026 370022 366021 364023 361025 359027 358029 357033
      359037 361036 363034 366032 368030 370028 371026
 0.50 332763 327763 323765 316772 312775 307777 303781 300785
      296794 294799 290799 279797 268796 262798 263803 265807
      271810 285822 289819 291814 293810 295808 298809 306814
      309816 311812 315802 319793 328774 331768 332763
 1.00 494038 492032 489030 481024 472021 467019 463016 454013
      450012 446012 439019 428020 409022 404022 404027 410034
      417040 421043 427043 446048 455049 466049 475048 480047
      484044 489042 494038
 1.00 308795 307793 306792 304793 304795 305796 306797 308795
 1.00 283806 283804 283802 281801 279801 277800 276800 274800
      272800 270801 270802 269804 271805 271806 272806 274806
      276807 278807 280807 282807 283806
 1.50 482037 476033 472032 470028 466023 459018 453016 446017
      441022 433023 418026 409026 411031 416036 418039 422040
      430041 438044 453044 461044 469042 482037
 2.00 463025 458019 453018 449019 442025 433026 425027 420029
      421034 424038 429039 438041 442041 445039 452039 457030
      463025
 3.00 438033 436032 435032 433031 431032 430032 429032 428035
      429035 431035 433036 435036 436035 438033