Weather Prediction Center

National Oceanic and Atmospheric Administration

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
247 AM EST Tue Nov 15 2016

Valid 12Z Tue Nov 15 2016 - 12Z Thu Nov 17 2016

...Coastal low to bring locally heavy rain to New England...

...Low pressure system to bring rain and snow to much of the
western U.S...

...Well above average temperatures continue for the central U.S...

A low pressure system will move northeastward along the
Mid-Atlantic and northeastern U.S. coastline today and Wednesday.
The system will produce widespread rain from portions of the
coastal northern Mid-Atlantic region to New England today, which
will persist into Wednesday across northern New England. Locally
heavy rainfall will be possible. Across the western U.S., a
Pacific storm system will move onshore today, spreading rain and
high elevation snows into the Northwest and northern Intermountain
Region to northern Rockies. As the system moves inland tonight and
tomorrow, a deepening upper-level trough across the West will
lower snow levels, with snow becoming more widespread across the
interior western U.S. on Wednesday and Wednesday night. Wednesday
night into Thursday morning, the system will begin to move from
the Rockies into the central plains, with the potential for snow
spreading into portions of the northern High Plains by that time.

High pressure aloft will remain in place across the central U.S.
today and Wednesday, keeping conditions generally dry with well
above average temperatures. Afternoon highs are forecast to be 15
to 25 degrees above average across the plains and portions of the
Upper Midwest today and Wednesday.

Across the Southeast, wildfires across the southern Appalachians
will continue to spread smoke across portions of northern Georgia,
eastern Tennessee, and western portions of the Carolinas. Portions
of these areas may experience reduced visibilities as well as
unhealthy air quality. Please refer to products issued by local
NWS forecast offices for further details on smoky conditions.


Ryan

Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1256 AM EST TUE NOV 15 2016

VALID 12Z FRI NOV 18 2016 - 12Z TUE NOV 22 2016

...IT'S BEGINNING TO LOOK A LOT LIKE...WINTER...


...OVERVIEW...

SIGNIFICANT SYSTEM WILL TRANSITION OUT OF THE SHORT RANGE (DAYS
2-3) AND INTO THE MEDIUM RANGE OVER THE UPPER MIDWEST ON FRIDAY
AND CONTINUE EASTWARD THIS WEEKEND. COLD FRONT AND A NEW LOW MAY
REORGANIZE NEAR NEW ENGLAND LATE THIS WEEKEND AND LIFT NORTHWARD
AND EASTWARD INTO CANADA AS COLDER AIR DESCENDS INTO THE EASTERN
HALF OF THE COUNTRY. THE WEST COAST WILL SEE AN UPPER TROUGH
APPROACH THE COAST AND THEN FINALLY MOVE INLAND, SPREADING RAIN
AND HIGH ELEVATION SNOW TO SOME OF THE SOUTHWESTERN STATES.


...GUIDANCE EVALUATION/PREFERENCES...

THROUGH THE 12 AND 18Z/14 GUIDANCE, OF WHICH THIS FORECAST WAS
BASED, THE MODELS/ENSEMBLES REMAINED STUCK IN THEIR RESPECTIVE
CAMPS WITH RESPECT TO THE ROBUST MIDWEST SYSTEM -- THE ECMWF AND
ITS ENSEMBLES QUICKER VS BASICALLY ALL OTHER GUIDANCE. THE
MULTI-DAY ONGOING WPC CONTINUITY CONTINUED TO OFFER THE BEST
MIDDLE GROUND SOLUTION. THIS WAS USED THROUGH MON/D6. HOW THE
EASTERN SYSTEM EVOLVES NEXT SUN/MON IS QUITE UNCERTAIN BUT IT DOES
APPEAR THAT A DEEPER SFC LOW MAY LIFT THROUGH NEW ENGLAND. WILL
LET THE DAY SHIFT DIGEST THE 00Z/06Z GUIDANCE BEFORE MAKING ANY
CHANGES. AGAIN, A MIDDLE GROUND BETWEEN THE GFS AND ECMWF WAS
PREFERRED.

IN THE WEST, INITIAL SYSTEM SHOULD LIFT NORTHWARD IN THE NORTHEAST
PACIFIC FRI/SAT AND APPROACH THE OR/WA COAST INTO SUNDAY. ENSEMBLE
SPREAD INCREASES WEST OF CALIFORNIA IN THE BASE OF THE TROUGH AS
VORTICITY DIVING DOWN FROM THE NORTH PACIFIC ROUNDS THE BASE ON
MONDAY. THIS SHOULD CARRY A COLD FRONT INTO SOUTHERN CALIFORNIA
BUT THE ECMWF ENSEMBLES BECOME MUCH QUICKER WITH THE TROUGH THAN
THE GFS ENSEMBLES. GIVEN THE LACK OF GOOD CONTINUITY WITH THE
EVOLUTION OF THIS FEATURE, OPTED TO SPLIT THE ENSEMBLE DIFFERENCE
FOR NEXT TUESDAY FOR NOW.


...WEATHER HIGHLIGHTS AND IMPACTS...

FOCUS WILL INITIALLY BE OVER THE HIGH PLAINS INTO THE MIDWEST AND
GREAT LAKES WITH RAIN IN THE WARM SECTOR AND SNOW TO THE NORTH AND
NORTHWEST OF THE SURFACE LOW. THOUGH PLACEMENT OF THE HEAVIEST
SNOW WILL CONTINUE TO WAVER, WIDESPREAD LIGHT TO MODEST AMOUNTS
ARE PROBABLE WITH SOME AREAS PERHAPS EXCEEDING A FOOT. MARGINAL
TEMPERATURES AND SNOW-TO-LIQUID RATIOS MAY AFFECT HOW MUCH SNOW
CAN ACCUMULATE. ALONG/AHEAD OF THE COLD FRONT, RAIN WILL BREAK OUT
NEAR AND EAST OF THE MISSISSIPPI VALLEY ONCE SOME LIMITED GULF
MOISTURE GETS TAPPED. THIS WILL THEN SPREAD INTO THE OH/TN VALLEY
AND CENTRAL APPALACHIANS THIS WEEKEND AND FINALLY INTO THE
NORTHEAST/MID-ATLANTIC AS THE UPPER TROUGH DIGS THROUGH THE
NORTHEAST, SUPPORTING A NEW SURFACE LOW. COLD AIR WRAPPING AROUND
THE SFC LOW OVER THE RELATIVELY WARM GREAT LAKES SHOULD SUPPORT
SOME LAKE-ENHANCED PRECIPITATION THIS WEEKEND INTO NEXT MONDAY.
TROUGHING JUST OFF THE WEST COAST SHOULD KEEP THE PRECIPITATION
AIMED AT NORTHERN CALIFORNIA AND POINTS NORTHWARD THIS WEEKEND.
DEPENDING ON HOW THE NEXT SYSTEM DEVELOPS FATHER SOUTH,
PRECIPITATION COULD SPREAD THROUGH SOUTHERN CALIFORNIA AND INTO
THE FOUR CORNERS REGION EARLY NEXT WEEK.

VERY WARM TEMPERATURES AHEAD OF THE EMERGING PLAINS STORM WILL
SLOWLY BE REPLACED BY NEAR TO BELOW AVERAGE TEMPS (BY ABOUT 5-15F)
THROUGH THE PERIOD, WHICH WILL LIKELY BE THE COLDEST AIR OF THE
SEASON FOR MANY, INCLUDING FLORIDA AND SOUTH TEXAS. THE
WEST/ROCKIES WILL SEE A WARMING TREND AS UPPER RIDGING MOVES IN
STARTING THIS WEEKEND, PUSHING TOWARD THE PLAINS BY NEXT TUESDAY. 


FRACASSO

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
556 AM EST TUE NOV 15 2016


FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID NOV 15/1200 UTC THRU NOV 18/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1...

...PACIFIC NORTHWEST/NORTHERN ROCKIES...

A DAY OF WIDESPREAD MODERATE PRECIPITATION IN STORE AS A LARGE
SCALE TROUGH BEGINS TO MOVE BODILY INLAND. THE PRECEDING RIDGE IS
SO ANOMALOUSLY MILD THAT THE ANTICIPATED 24-HOUR HEIGHT FALLS ARE
GREATER THAN 200 METERS IN THE GREAT BASIN AND NORTHERN
CALIFORNIA...WITH LESSER BUT STILL SIGNIFICANT HEIGHT FALLS
THROUGHOUT THE REMAINDER OF THE WESTERN STATES. MOISTURE
CONTENT...HOWEVER...IS SOMEWHAT MARGINAL...AND WITH NO SUBSTANTIAL
CYCLOGENESIS SLATED TO TAKE PLACE UNTIL THIS SYSTEM REACHES THE
PLAINS...THE PRECIPITATION OVER THE WEST SHOULD FALL OUT IN A
RATHER EVEN DISTRIBUTION OF LIGHT TO MODERATE AMOUNTS...WITH
LITTLE INDICATION OF PARTICULARLY HEAVY AMOUNTS ON DAY 1. OUR
IN-HOUSE ENSEMBLE USUALLY PERFORMS WELL DURING HEAVIER EVENTS IN
THE NORTHWEST...BUT IN THIS CASE IT APPEARS TOO LIMITING OF THE
COVERAGE AND INTENSITY OF THE LIGHTER PRECIPITATION.
THEREFORE...BASED ON MASS FIELD ARGUMENTS...WPC FAVORED THE GFS
AND ECMWF...WHILE ALSO LOOKING TO MAINTAIN SOME PERCENTAGE OF
CONTINUITY. THE NAM CONUS NEST AND WRF-ARW HELPED FILL IN SOME OF
THE HIGHER RESOLUTION DETAIL IN OUR MANUAL CONTOURS BEFORE TURNING
THE PROCESS OVER TO THE DOWNSCALING SCHEMES. THE RESULTING WPC QPF
IS VERY SIMILAR TO THE GEFS REFORECAST DATA BASED ON ANALOG
EVENTS. THE COASTAL HIGH TERRAIN IN SOUTHWEST OREGON AND THE
MOUNTAINS IN CENTRAL/NORTHERN IDAHO INTO WESTERN MONTANA ARE BEST
ALIGNED TO INTERCEPT THE NARROW PLUME OF SLIGHTLY ANOMALOUS
MOISTURE COINCIDING WITH THE SURFACE FRONTAL PUSH TODAY AND
TONIGHT. AREAL AVERAGE AMOUNTS WILL LIKELY TOP ONE INCH LIQUID IN
THESE AREAS...AND IN OTHER SPOTTY LOCATIONS THROUGHOUT THE
CASCADES IN BOTH WASHINGTON AND OREGON. THE SOUTHERN EXTENT OF
MEANINGFUL PRECIPITATION LOOKS TO DIP INTO THE NORTHERN SIERRAS
THROUGH WEDNESDAY MORNING.


...EAST COAST / INCLUDING NEW ENGLAND AND SOUTH FLORIDA...

A LARGE SCALE...ROUGHLY NEUTRALLY TILTED TROUGH WILL CONTINUE TO
SHARPEN UP DURING THE DAY 1 PERIOD. ONCE AGAIN THE MORE
VIGOROUS...CONVECTIVELY ENHANCED PRECIPITATION...WILL REMAIN
LARGELY OFFSHORE. WE WILL TRY THIS ONCE AGAIN ALONG THE EAST
COAST...AFTER HAVING SEEN THE UPPER TROUGH PRODUCE VERY LITTLE IN
THE WAY OF SIGNIFICANT RAINFALL OVER THE MID ATLANTIC ON
MONDAY...OWING TO DRY AIR INFLUENCE. THE MODELS CONTINUE TO INSIST
GREATER COVERAGE OF AMOUNTS 0.50 INCHES AND HIGHER WILL OCCUR FROM
SOUTHERN NEW YORK THROUGHOUT COASTAL NEW ENGLAND UP TO DOWN EAST
MAINE. THIS...AS A MID LEVEL CIRCULATION BECOMES A BIT BETTER
DEFINED...AND MID LEVEL ASCENT SHOULD INTENSIFY A BIT AS THE LOW
CLOSES OFF AND LIFTS THROUGH THE EASTERN SIDE OF THE LARGE SCALE
TROUGH. AGAIN...THE CONVECTION OFFSHORE MAY INHIBIT DEEPER
MOISTURE FROM COMING ONSHORE...AND THE ANTECEDENT AIRMASS OVER NEW
ENGLAND WAS EQUALLY AS DRY AS IT HAD BEEN IN THE MID ATLANTIC ON
MONDAY...SO WE TRIED TO TAKE A MORE CONSERVATIVE APPROACH. TO DO
SO WE INCORPORATED SOME ENSEMBLE MEANS...BLENDING THE PREVIOUS WPC
FORECAST TOWARD THE SREF MEAN AND ECMWF ENSEMBLE MEAN...WHILE THE
DOWN-SCALED VERSION OF OUR IN-HOUSE ENSEMBLE ALLOWED US TO ADD
BACK IN SOME DETAIL. THE RESULT WAS A REDUCTION OF AMOUNTS OVER
MAINE...AND VERY SLIGHT INCREASE DOWN THE COAST INTO
MASSACHUSETTS...ESSENTIALLY WORKING TOWARD A MORE UNIFORM SWATH OF
AMOUNTS APPROACHING OR SLIGHTLY EXCEEDING ONE INCH LIQUID. THIS
APPROACH IS CERTAINLY MORE CONSERVATIVE THAN THE ECMWF...AND THE
RAW OUTPUT FROM OUR IN-HOUSE ENSEMBLE...WHICH WAS PERHAPS INFLATED
BY THE ECMWF.


...ELSEWHERE...INCLUDING THE GREAT LAKES AND LOWER MISSISSIPPI
VALLEY...

WARM ADVECTION AND THEN HEIGHT FALLS ASSOCIATED WITH A SHARPENING
SHORTWAVE TROUGH WILL DRIVE THE GENERATION OF LIGHT PRECIPITATION
OVER THE NORTHERN GREAT LAKES. MODELS SHOW A SURPRISING AMOUNT OF
SIMILARITY IN THE COVERAGE OF MEASURABLE PRECIPITATION...WITH
AMOUNTS GREATER THAN A TENTH OF AN INCH BEING FAVORED JUST NORTH
AND EAST OF THE SURFACE LOW TRACK / WARM FRONT. PROBABILITIES OF
24-HOUR 0.10 AND 0.25 INCH PRECIPITATION FROM THE ECMWF ENSEMBLE
WERE USEFUL...IN ADDITION TO A BLEND THAT INCLUDED THE GFS/ECMWF
AND PREVIOUS WPC FORECAST.

DOWN IN THE LOWER MISSISSIPPI VALLEY...SCATTERED CONVECTION
BREAKING OUT THIS MORNING IN ADVANCE OF AN ENERGETIC DIGGING
WAVE...WILL BECOME LESS AND LESS SUPPORTED OVER TIME...AS MID
LEVEL ASCENT MOVES OFF OF THE NARROW INSTABILITY AXIS BY MIDDAY
TUESDAY. WPC BLENDED THE PREVIOUS MANUAL QPF TOWARD THE LATEST
GLOBAL AND HI-RES MODEL CONSENSUS...BUT THERE WAS REALLY VERY
LITTLE CHANGE AND SHOULD BE VERY LITTLE IMPACT FROM THIS LIGHT
AREAL AVERAGE PRECIPITATION.


DAYS 2 AND 3


...WEST COAST TO THE ROCKY MOUNTAINS AND ADJOINING
WESTERN/NORTHERN HIGH PLAINS...

A TROF...WHICH HAD BEEN A DEEP UPPER LEVEL VORTEX OVER THE GULF OF
ALASKA...WILL BE WEAKENING AS IT APPROACHES THE WEST COAST OF THE
U.S. AT THE START OF THE DAY 2 PERIOD AT 16/12Z.  THE AXIS OF 120
TO 140 KT UPPER LEVEL JET MAKING ITS WAY EASTWARD ACROSS THE ERN
NOPAC WILL HELP SHARPEN THE TROUGH OVER THE INTERMOUNTAIN REGION. 
THE RESULT SHOULD BE SOME WIDESPREAD BUT GENERALLY LIGHT PCPN WITH
SOME ENHANCED AMOUNTS IN REGIONS OF OROGRAPHIC LIFT.

AS THE TROF AMPLIFIES ON WEDNESDAY AND WEDNESDAY NIGHT...THE
HEIGHT FALLS SPREADS EASTWARD ACROSS THE INTERMOUNTAIN REGION AND
THE ROCKIES AND EVENTUALLY LEADS TO SURFACE CYCLOGENESIS OVER THE
PLAINS ON THURSDAY AND THURSDAY NIGHT.  THERE HAS BEEN LITTLE
AGREEMENT BETWEEN THE VARIOUS GLOBAL MODELS GOING BACK SEVERAL
DAYS INTO THE MEDIUM RANGE PERIOD...AND NOT A LOT OF RUN TO RUN
CONSISTENCY BY ANY PARTICULAR MODEL.  THE ECMWF HAD BEEN ON THE
FAST SIDE OF THE GUIDANCE AND WAS CONSEQUENTLY TO THE EAST OF THE
OTHER MODELS BEFORE IT DEEPENS THE SURFACE LOW.  THIS HAD BIG
CONSEQUENCES WITH RESPECT TO WHERE PCPN FORMS AND FOR
PRECIPITATION TYPE. 

THE 15/06Z WPC QPF WAS LARGELY BASED ON A SOLUTION CLOSER TO THE
GFS/NAM SOLNS AND NOT AS FAST AS THE 14/12Z ECMWF WHILE THE DAY 3
FORECAST WAS BASED LARGELY ON THE WPC MEDIUM RANGE SURFACE PROGS.
THE SHIFTS IN THE 00Z NUMERICAL GUIDANCE WAS TOWARD THE PREFERRED
WPC SOLN ON DAY 3 WHICH RESULTED IN FEW CHANGES BEING MADE FOR THE
15/12Z WPCQPF PACKAGE. STILL SUSPECT THERE WILL BE CHANGES IN THE
FORECAST INTENSITY AND FORECAST TRACK OF THIS SYSTEM DURING THE
NEXT COUPLE OF DAYS.

REFER TO THE WPC WINTER WEATHER DESK FORECAST GRAPHICS AND
DISCUSSION FOR DETAILS ABOUT THE POTENTIAL FOR MODERATE TO HEAVY
SNOW FROM THIS SYSTEM ON DAY 3 ACROSS THE UPPER MIDWEST.


---NORTHEAST U.S.---

GENERALLY LIGHT TO MODERATE PRECIPITATION WILL BE CONTINUING
ACROSS THE EASTERN PORTION OF MAINE EARLY ON DAY 2 AS A SURFACE
LOW PRESSURE SYSTEM MOVES NORTHEAST ALONG THE COASTLINE. 
PRECIPITATION WILL BE TAPERING OFF WEDNESDAY NIGHT/EARLY THURSDAY
AS THE CENTER OF LOW PRESSURE AND THE TROF AXIS IN THE LOW LEVELS
SHIFTS OFF THE COAST.

BURKE/BANN


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


24HR QP VT 16/12Z
 0.01 536204 538191 540175 541161 540149 533095 529073 526064
      524052 519028 513019 508011 503003 498997 496994 491995
      488997 486001 485014 486030 485037 487041 486048 484052
      482062 480068 480075 476084 475087 473088 470085 464083
      460080 456079 454082 455087 451089 443093 436094 432092
      428091 427096 430098 430101 429107 424110 425114 425122
      424126 423129 418139 414146 409154 405161 396177 395182
      400183 400187 401193 403194 402197 397197 386194 382194
      379192 374191 373196 375200 377204 378207 381210 383215
      381217 378216 376214 372218 371224 368229 369233 368237
      371244 378249 382251 386251 394251 404255 410257 416259
      435261 467262 472263 477265 481267 484271 491280 495284
      500286 504288 507286 510283 512278 515275 518271 519266
      520259 521252 520247 517234 519231 521232 524229 530221
      533211 536204
 0.01 500693 499686 497682 491675 486669 479665 470661 461657
      452655 443656 440655 435655 431655 426656 420659 417662
      411668 390670 369674 335691 332694 327696 319701 303717
      292729 282742 275750 268757 263755 259756 251761 240772
      235778 232788 230797 229810 228835 227838 228843 230846
      235847 239848 241844 244836 248826 252816 254813 260812
      267805 272799 274795 277793 286778 292769 298762 304754
      312748 318743 327739 344731 366725 372725 378725 387726
      390729 390734 389739 390743 395752 400758 409763 419765
      424765 429765 434761 439760 448759 455753 462753 470747
      479740 483736 485732 487727 488720 490715 493710 498703
      500693
 0.01 512921 512914 512906 509897 504869 502865 499861 494854
      483839 477832 471826 468823 466822 465817 461807 457800
      451794 447790 443788 438788 435786 426786 422787 418789
      415792 412796 413804 415807 422812 425814 428818 432826
      434830 434834 433840 433846 432851 432857 434862 438873
      443875 445877 456891 460901 458913 458927 461936 462942
      465949 469950 472947 475945 480944 488943 493942 497940
      502939 505935 509929 512921
 0.01 494115 494112 493110 493109 491107 490109 488111 486111
      484113 486115 487115 489115 491116 492116 494115
 0.01 475197 474194 472191 470189 467188 464189 462191 461193
      459195 457197 455201 458204 461204 464205 466204 469202
      471201 473199 475197
 0.01 348875 348870 346868 343869 334873 328874 325876 321879
      318885 315896 313901 313907 315911 319913 323913 328909
      333900 339893 344884 347879 348875
 0.01 231977 233978 237978 241978 244978 246978 250976 252976
      254974 254972 254970 250970 246969 243970 242970 239969
      237969 233971 231971
 0.25 528202 530196 530191 529185 530177 531162 530152 530140
      528127 526126 524132 522140 523147 522156 520162 519161
      507151 499146 495143 493140 487132 480128 472127 465124
      462124 463119 465115 466111 466105 464101 456101 452100
      449102 447109 448116 450123 449129 446132 436142 432153
      432158 434162 436167 435172 437173 441171 444174 445177
      446183 448187 456185 462183 465171 472168 476169 479172
      483181 484185 487188 488192 487196 481201 476204 469208
      461210 453212 444213 430214 423212 418213 413213 411209
      402206 393201 388201 385205 386210 392216 398220 399224
      396227 393230 391236 395240 399243 407248 415251 431253
      438253 445252 453252 462252 467253 473255 478258 482259
      490260 493257 494253 499247 502244 503240 504225 506216
      509212 515208 519207 522204 524200 526199 528202
 0.25 481693 481687 479683 473678 467674 460672 443668 438669
      433671 425676 419680 410680 394679 374682 363686 353690
      338696 323705 316710 308717 302723 297730 295737 288741
      283747 280755 274763 272767 269769 266767 263768 259767
      255769 250774 246781 240795 237803 235813 233824 232828
      233833 234837 236839 242833 245826 247818 251808 254806
      261805 266799 270791 273785 277778 285765 294750 300743
      309739 339723 347721 358718 368716 379717 388716 394715
      398714 399718 401731 401739 404744 414745 419743 423741
      427741 431740 448734 452728 454718 456714 459715 461722
      463728 467729 470728 474719 480708 481700 481693
 0.25 431171 432169 432166 431164 430162 428162 427163 426164
      425165 424167 424169 425171 427172 429171 430171 431171
 0.25 420207 422205 421202 420204 420207 420207
 0.50 514184 516177 514172 511167 508164 492161 487160 483158
      477156 475151 470144 466141 460139 455140 453142 449146
      444147 438146 436149 435152 436155 439159 445165 448168
      452170 454169 460163 463161 468163 471162 475159 479159
      482163 487172 490174 493178 498181 503182 512187 514184
 0.50 498229 499221 499213 498210 494208 489206 487204 484204
      480206 472211 463213 453216 442216 433220 428222 426227
      425232 422233 416233 412234 410235 408239 409243 414247
      424248 437248 457246 461245 467245 474248 478251 484253
      487249 488243 486236 489232 492231 496231 498229
 0.50 480229 480228 478228 477227 477228 478228 480229 480229
 0.50 488141 488139 487138 486136 486135 484135 482134 481133
      479133 477133 476133 475134 476135 477137 479137 480138
      482138 484139 485140 487141 488141
 0.50 476704 476697 473692 469689 467684 463680 458679 448677
      444675 438676 433679 430683 424694 421699 418703 415701
      414692 408686 403685 396685 384685 373686 362689 349695
      338700 321710 313717 309722 307726 309730 314730 320729
      324727 336721 348717 360714 371713 377714 385712 391710
      395706 399704 405702 407702 408704 406709 404715 403722
      405738 407741 412739 420733 425732 431732 434730 435727
      438721 442720 446716 450706 454703 458702 464705 467709
      469712 473710 476704
 0.50 407220 407215 405212 404212 400210 399208 396205 394204
      392204 390207 390209 392211 394213 396215 399217 403219
      404219 407220
 0.50 269785 268781 266781 260778 254779 250786 244797 241801
      239807 237814 236822 235828 236832 238835 242830 243823
      244817 247808 249804 251802 254802 258803 261801 264794
      267790 269785
 1.00 490219 491216 490216 489214 488213 487212 486211 484210
      483210 481210 480211 479212 478213 478215 478217 479218
      480219 481220 483220 485220 486221 488221 490219 490219
 1.00 469155 469153 469152 468150 467149 466147 464146 463145
      461144 459144 458145 457146 457147 457150 459151 460151
      460150 462150 464150 465152 467154 468155 469155 469155
 1.00 455690 455687 453686 447685 444685 441686 439690 435699
      428707 424710 419713 414713 411717 414721 417724 423723
      427719 431710 437708 441704 448697 452694 455690
 1.00 453159 453156 451155 450155 448155 446155 444154 443154
      441154 440154 443155 446156 448157 449159 450161 451162
      452161 453160 453159
 1.00 421241 421240 419239 418239 419240 421241 421241
 1.00 395696 391692 384690 378690 370691 363693 356696 350700
      342703 337706 330710 327714 328718 332718 339717 348714
      353712 360711 367710 374711 382710 389707 393701 395696
 1.50 388702 388700 387700 386700 384700 382701 380701 379701
      377702 375703 375706 376708 378708 379708 381708 383708
      385707 386705 388703 388702
 1.50 383692 374693 369695 363696 359698 355701 353704 348706
      338709 336712 340713 351709 359707 368705 370703 369700
      378696 383692 

24HR QP VT 17/12Z
 0.01 456625 465627 472629 476630 481628 486626 491625 495627
      498630 503636 508645 511649 513656 521678 522683 524693
      523707 524715 523721 521731 519735 516738 507745 499747
      494748 491747 482748 477747 473743 473738 474732 472727
      468724 462719 457718 452719 446721 443724 441726 437724
      435722 434715 436705 438699 440694 440690 438685 435683
      431682 420682 401684 397683 390684 383683 375679 371675
      372669 374664 381658 389651 400643
 0.01 531195 531183 527173 519160 516153 514150 511147 508145
      506142 502136 498128 492121 489118 483117 478116 476111
      474101 471095 467089 466086 467080 471057 472051 470048
      468048 466051 475016 479006 482002 482995 481992 478992
      474994 471996 465000 461006 458010 457013 454022 450031
      448034 444037 441038 441043 442048 440051 434055 428060
      424063 419068 412068 408067 405070 399075 393078 391080
      392085 399090 404092 404095 405102 402106 387111 381114
      376120 373128 372131 373135 383145 386145 389141 392142
      392146 388153 384161 383165 384169 384175 385177 390183
      398187 404185 408184 408180 410178 415172 419166 427153
      427144 429134 434129 438132 439134 438138 436144 434149
      434156 435160 437163 440165 443171 447178 441183 440187
      443189 448190 451193 456188 461184 464181 464176 460172
      457166 457162 461162 466167 474170 486182 488187 489192
      487195 484198 470205 464209 460209 456211 451213 443214
      430216 419225 416226 415220 412216 416215 418211 419206
      419203 421200 420197 415195 406194 400195 393199 386201
      380196 376190 369186 367183 365182 362186 366194 371199
      376201 379204 384205 389207 393211 397214 402215 406217
      404222 402226 398226 386232 380236 377240 376245 381260
      393260 402262 406262 410262 414261 419263 429266 438269
      445268 452266 459265 466263 470262 473264 477273 480282
      484289 492293 495294 498292 501286 502280 501274 506269
      510263 513253 514246 514239 512228 508219 505210 505203
      509201 513201 519202 524204 527203 531195
 0.01 540092 541076 540063 539049 537037 533015 534008 534999
      534984 533978 533971 533965 532959 530946 530928 528922
      528918 525906 521896 517887 511881 507882 504885 504892
      506896 507903 507907 505907 501905 497905 493906 491910
      490914 490922 491931 492937 492949 489949 487954 487967
      490980 496999 499011 503021 505024 507029 507038 506053
      507059 509064 512069 515069 517074 518079 520091 522096
      524102 530103 532104 534103 538097 540092
 0.01 495794 494789 493787 488785 484785 481784 474784 462782
      455780 451777 439774 432773 425773 418772 411774 403776
      397779 389787 379798 376803 374808 381806 384805 387803
      393800 396798 399800 406799 411803 437799 442802 446806
      457813 462815 469814 477813 483810 488808 491805 495794
 0.01 488879 488874 486871 483867 479864 475860 469860 465863
      466871 469876 474878 480882 485882 488879
 0.01 467127 466126 465125 463124 461126 463128 464128 466128
      467127
 0.01 455823 455820 455818 454817 453816 452815 451814 451813
      449813 447813 447814 446817 445817 445819 446822 446824
      448826 450826 451826 453826 455823 455823
 0.01 438763 437758 436756 435753 431752 429752 428754 426755
      424758 423761 422763 423765 425767 428768 431767 434766
      436765 438763
 0.01 423100 422099 420098 418098 417098 415099 413099 411099
      409101 410103 411105 413105 414105 416105 417104 418103
      420103 421102 422102 423100
 0.01 335169 334168 332168 331166 330166 329165 327164 325165
      324165 325166 327166 328168 330167 332169 333169 335169
      335169
 0.01 313727 312719 307716 304716 300719 295722 284731 273739
      264748 255759 248769 241781 234791 231798 229805 230809
      232812 237814 239822 243823 245822 248817 251810 254804
      258799 267790 275780 283769 292759 301749 309737 312732
      313727
 0.25 515693 514680 512669 509659 504652 500648 494646 488645
      482641 470637 464635 457634 449636 442635 435641 431646
      416650 409654 402658 396663 393668 395671 398674 403676
      418676 432677 440679 444683 448690 454694 461694 464694
      467696 471704 472708 475711 480713 487714 495714 502713
      507710 511705 514699 515693
 0.25 516180 516179 515177 515176 513174 512174 510174 509175
      509178 510178 511181 513181 514181 516180 516180
 0.25 524033 524031 524028 524027 523025 522023 521020 521017
      521015 520017 519019 519020 519022 518025 518028 518030
      519032 519033 520035 522035 523036 524033
 0.25 522015 523012 522012 521015 522015 522015
 0.25 501238 500232 498224 497218 495215 492213 487213 481212
      475214 476217 481218 486221 491224 495229 498234 501238
 0.25 499170 501163 500157 498146 496141 493138 486131 483129
      478129 475131 474136 475140 478143 482151 483154 482156
      480158 483163 488162 490162 493167 495171 499170
 0.25 487251 487246 485241 478233 471227 466217 459216 454217
      450220 445226 437229 433231 430233 425235 421236 412237
      408239 405243 406248 409251 414254 420256 425257 429257
      438255 454250 463251 470251 475253 479255 482255 487251
 0.25 472156 472153 471150 469148 466145 463145 459144 458145
      457149 459151 462153 464154 467156 470156 472156
 0.25 462114 464107 463103 460094 459083 457078 455074 450068
      448064 443064 440066 439070 439074 439079 440083 440086
      439088 433093 428088 426083 423084 423088 425091 431097
      430102 428105 424107 424112 424117 426120 431121 434120
      449121 455120 459117 462114 462114
 0.25 405116 404116 403116 404116 405116
 0.25 393124 393123 391122 390123 391124 393124 393124
 0.25 278755 278751 275750 268753 259762 251771 244782 239793
      239800 239804 241806 245806 247804 252799 258789 265778
      272767 278755 278755
 0.50 507669 506664 505661 501658 496657 490657 482649 476645
      471645 468646 467650 467652 463653 452657 449663 444663
      441662 440658 438654 435652 430651 425652 419655 413660
      408664 407665 406668 408669 419672 425672 431671 437673
      442676 450684 456687 462687 467688 472690 476695 480700
      485699 490696 503689 505685 506680 507669
 0.50 486139 486137 484136 484135 482135 481135 482138 484138
      485140 486139
 0.50 460240 457237 453235 450235 444235 441235 437238 436242
      439245 444245 448244 452243 456242 459240 460240
 0.50 460111 459103 456098 452093 446095 441098 437101 436104
      437107 440114 445116 450116 455114 460111
 0.50 424246 423245 423243 422243 420242 419242 417241 415243
      415246 416246 418247 419247 420247 421247 423246 424246
 0.50 267765 265762 262764 257769 253775 249780 245786 243793
      243798 246799 251794 254789 258783 262776 265770 267765 

24HR QP VT 18/12Z
 0.01 501280 504271 503264 501259 500253 498247 495243 490240
      486236 482233 476231 467232 457233 448234 439236 428237
      417235 417239 418243 422247 424252 430254 435254 454252
      466255 475261 482270 487280 490284 496286 499284 501280
 0.01 507245 506238 503232 498221 493216 489212 476209 465211
      461213 458217 459222 464221 468218 471218 473217 485220
      490223 493227 499238 503244 505246 507245
 0.01 516150 515141 513138 510136 498128 485120 482114 480109
      480104 479100 479094 480082 482056 483052 483047 482044
      482038 479024 478022 478017 480008 483999 485992 490974
      493965 495956 499939 502917 505902 508882 508872 509868
      510860 511840 511827 511817 511804 510794 504779 494790
      490795 487800 481812 478820 473828 471846 468866 466884
      464892 461899 458908 455913 451919 449921 445923 443925
      438925 431925 424927 415928 407929 404930 400930 369936
      362938 355938 353940 349940 346941 344943 333952 323959
      312968 308973 306981 306985 309986 317986 329979 335974
      342972 353965 364961 377957 386956 389955 392958 403966
      404969 400970 396970 393972 389972 387974 380975 373976
      370978 367978 362980 359980 357984 357987 359989 366994
      380997 387000 393005 395009 395014 392023 387037 386043
      385047 382054 376053 369053 365053 363055 359058 357060
      358065 363070 368075 371079 373089 375091 379092 383093
      385095 390100 397105 396110 394111 387111 382115 379121
      377127 376130 380131 384129 387126 390125 393124 396122
      398124 408121 502160 508162 512160 516150
 0.01 479150 478148 476147 476146 475144 473144 473143 472141
      470143 471145 473148 474148 475149 476151 477151 479150
 0.01 462181 463176 462175 456172 455159 455157 452155 448153
      440149 438151 437154 437158 439159 442164 445167 448172
      447177 446181 444184 441185 443190 447192 451196 454191
      460184 462181
 0.25 497268 496260 493254 489250 483247 481241 480238 477236
      470235 465235 455237 449239 450242 461242 468243 473244
      478247 482250 485257 489262 493266 497268
 0.25 493896 494885 493875 491857 489850 487850 484857 483864
      476894 473909 470922 466937 460949 454959 448969 439978
      428981 421987 417992 414998 417005 421009 422015 420023
      417027 415033 415038 412043 408049 408055 412059 415061
      419060 423063 425066 424070 421075 418078 414085 413088
      414092 418095 425097 431097 436095 441093 447092 457094
      461079 464063 464048 463039 464029 467015 470001 472993
      474987 478971 481955 482947 483939 487925 493896
 0.25 461114 461109 460106 459103 457101 456098 453096 451100
      450102 448104 447106 446111 448114 450116 453117 457116
      459116 461114
 0.25 414073 412068 408065 403065 399068 395071 391069 389071
      388073 390081 395080 401078 404078 409075 412073 414073
 0.50 473969 473962 470958 467955 464958 460961 459965 455976
      453986 454991 452995 447003 444007 443012 441017 439020
      436023 436030 433043 439050 443051 444046 446040 451031
      453020 458012 462003 465993 469982 473969
 0.50 450068 450064 449061 447058 446057 442057 440059 438061
      437064 437069 438072 441074 445074 447072 449070 450068 

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
904 AM EST TUE NOV 15 2016

...VALID 15Z TUE NOV 15 2016 - 12Z WED NOV 16 2016...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS
THAN 2 PERCENT.

HURLEY

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
236 AM EST TUE NOV 15 2016

VALID 12Z TUE NOV 15 2016 - 12Z FRI NOV 18 2016


DAYS 1 THROUGH 3...

...NORTHWEST/NORTHERN ROCKIES/NORTHERN PLAINS/UPPER MISSISSIPPI
VALLEY...

THE FIRST SIGNIFICANT SNOWSTORM TO MOVE OUT OF THE ROCKIES INTO
THE PLAINS STATES AND UPPER MISSISSIPPI VALLEY IS IN THE FORECAST.
 A SHARP DEEPENING UPPER LEVEL TROUGH THAT BECOMES NEGATIVELY
TILTED BY THURSDAY NIGHT INTO FRIDAY...WILL PROVIDE THE
INGREDIENTS FOR HEAVY SNOW ESPECIALLY ACROSS NORTHERN WYOMING AND
SOUTHERN AND WESTERN MONTANA INTO PORTIONS OF THE NORTHERN PLAINS
AND MINNESOTA

WHILE THERE HAS BEEN CONSIDERABLE MODEL ENSEMBLE VARIABILITY WITH
THIS SYSTEM...WITH THE GEFS VS ECMWF ENSEMBLES DEPICTING QUITE A
SPREAD WITH THE SLOWER GEFS VS FASTER ECMWF KEEPING UNCERTAINTY
QUITE HIGH FOR THE PAST COUPLE DAYS...PERHAPS  MORE CLARITY WAS
INTRODUCED BY THE MODEL SOLUTIONS TONIGHT AS THE 00Z GFS/NAM
SHIFTED FASTER WHILE A LOOK AT THE PARALLEL VERSION OF THE ECMWF
SHOWED A SLOWER VERSION THAN THE OPERATIONAL 12Z ECMWF...WHICH WAS
REPRESENTATIVE OF THE ECMWF ENSEMBLE MEANS. WITH THOSE KIND OF
DIFFERENCES...WITH BASICALLY TWO DISTINCT SET OF SOLUTIONS PRIOR
TO THIS EVENING...THE FORECAST WAS CLEARLY DIFFICULT. 
HOWEVER...NEW SET OF OPERATIONAL RUNS THIS EVENING POINTS TO A
MORE COMPROMISED SOLUTION BETWEEN THE EARLIER 2 CAMPS...WITH A
LITTLE MORE CONFIDENCE IN THE SNOWFALL FORECAST ISSUED THIS
EVENING.  WHILE THERE STILL REMAINS QUITE A BIT OF
UNCERTAINTY...THE 00Z ECMWF HAS TRENDED SLIGHTLY SLOWER THAN ITS
PREVIOUS RUN...AGAIN BOLSTERING A COMPROMISE SOLUTION. 
DIFFERENCES BETWEEN THE OPERATIONAL RUNS HAVE DIMINISHED THIS
EVENING.

DAY 1...

A LEAD SHORTWAVE AHEAD OF THE MAJOR TROUGH MOVES EASTWARD THROUGH
TUESDAY DROPPING SNOW LEVELS ACROSS THE NORTHWEST AND SENDING A
STREAM OF MOISTURE EASTWARD PRODUCING THE GREATEST CHANCE OF HEAVY
SNOW ACROSS THE WASHINGTON CASCADES...WITH A MODERATE TO HIGH
LIKELIHOOD OF GREATER THAN 8 INCHES OF SNOW ESPECIALLY ACROSS THE
NORTHERN CASCADES NEAR THE CANADIAN BORDER.  FOUR TO 8 INCHES OF
SNOW IS MORE LIKELY ACROSS THE OREGON CASCADES INTO THE
BITTERROOTS/SALMON RIVER AND SAWTOOTH MOUNTAINS IN IDAHO AND
WESTERN MONTANA...AS WELL AS THE HIGHER ELEVATIONS OF THE
MOUNTAINS OF EXTREME NORTHERN CALIFORNIA/BLUE MOUNTAINS AND THE
ABSAROKA RANGE IN SW MONTANA.

DAY 2...

AN AMPLIFYING UPPER TROUGH ACCOMPANIED BY A 150+ KT JET DRIVING
THE TROUGH EAST/SOUTHEASTWARD IS ACCOMPANIED BY A STRONG COLD
FRONT DRIVING EASTWARD ACROSS THE INTERMOUNTAIN WEST. HEAVY SNOW
IS EXPECTED TO DEVELOP IN THE COLDER AIR BEHIND THE FRONT AND
BECOMING HEAVY ESPECIALLY ACROSS NORTHERN/NORTHWESTERN WYOMING AND
ACROSS SOUTHWESTERN AND SOUTHERN MONTANA...WHERE RAIN IS EXPECTED
TO CHANGE TO SNOW.  A MODERATE TO HIGH PROBABILITY OF 4 TO 8
INCHES OF SNOW IS FORECAST ACROSS ALL OF NORTHWESTERN WYOMING AND
AND GOOD CHUNK OF SOUTHWESTERN MONTANA WITH A MODERATE PROBABILITY
OF GREATER THAN 8 INCHES SNOW AND A LOW PROBABILITY OF GREATER
THAN 12 INCHES ALTHOUGH THERE IS A MODERATE TO HIGH PROBABILITY OF
LOCAL AREAS OF SOUTHWESTERN MONTANA RECEIVING GREATER THAN 12
INCHES OF SNOW AGAIN OVER THE ABSAROKA RANGE. 

DAY 3...

AS THE TROUGH BEGINS TO BECOME NEGATIVELY TILTED...AN AREA OF LOW
PRESSURE IS EXPECTED TO DEVELOP FROM EASTERN COLORADO
NORTHEASTWARD ACROSS KANSAS INTO IOWA.  EARLIER RUNS OF THE ECMWF
HAD THIS SYSTEM DEVELOPING EXPLOSIVELY BUT NOW APPEARS TO HOLD UP
THE MAJOR DEVELOPMENT UNTIL LATE IN THE PERIOD OR EVEN BEYOND.  AS
A RESULT...SNOWFALL SPREADS EASTWARD AND EVEN SOUTHWARD INTO
COLORADO BUT THE MAJOR EXPANSION IS FROM NORTHERN WYOMING INTO
WESTERN SOUTH DAKOTA TOWARD NORTHEASTERN SOUTH DAKOTA/SOUTHEASTERN
NORTH DAKOTA INTO NORTHWESTERN MONTANA.  THIS PERIOD IS
CHARACTERIZED BY A MODERATE TO HIGH PROBABILITY OF 4 TO 8 INCHES
OF SNOW ACROSS MUCH OF CENTRAL AND EASTERN WYOMING ACROSS WESTERN
AND CENTRAL SOUTH DAKOTA INTO SOUTHEASTERN NORTH DAKOTA...WITH
MOSTLY MODERATE PROBABILITIES ACROSS SOUTH DAKOTA INTO NORTH
DAKOTA INDICATING REMAINING UNCERTAINTY.  AT PRESENT...THERE IS
ONLY A LOW PROBABILITY OF GREATER THAN 8 INCHES OF SNOW DUE TO
REMAINING SPREAD OF SOLUTIONS THAT MAY HAVE A BETTER HANDLE ON
WHERE THE AXIS OF HEAVY SNOW IS EXPECTED FROM THE NORTHERN PLAINS
INTO THE UPPER MISSISSIPPI VALLEY WITH THE NEXT SET OF MODEL
SOLUTIONS ON TUESDAY. 

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.

HAYES

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1256 AM EST TUE NOV 15 2016

VALID 12Z FRI NOV 18 2016 - 12Z TUE NOV 22 2016

...IT'S BEGINNING TO LOOK A LOT LIKE...WINTER...


...OVERVIEW...

SIGNIFICANT SYSTEM WILL TRANSITION OUT OF THE SHORT RANGE (DAYS
2-3) AND INTO THE MEDIUM RANGE OVER THE UPPER MIDWEST ON FRIDAY
AND CONTINUE EASTWARD THIS WEEKEND. COLD FRONT AND A NEW LOW MAY
REORGANIZE NEAR NEW ENGLAND LATE THIS WEEKEND AND LIFT NORTHWARD
AND EASTWARD INTO CANADA AS COLDER AIR DESCENDS INTO THE EASTERN
HALF OF THE COUNTRY. THE WEST COAST WILL SEE AN UPPER TROUGH
APPROACH THE COAST AND THEN FINALLY MOVE INLAND, SPREADING RAIN
AND HIGH ELEVATION SNOW TO SOME OF THE SOUTHWESTERN STATES.


...GUIDANCE EVALUATION/PREFERENCES...

THROUGH THE 12 AND 18Z/14 GUIDANCE, OF WHICH THIS FORECAST WAS
BASED, THE MODELS/ENSEMBLES REMAINED STUCK IN THEIR RESPECTIVE
CAMPS WITH RESPECT TO THE ROBUST MIDWEST SYSTEM -- THE ECMWF AND
ITS ENSEMBLES QUICKER VS BASICALLY ALL OTHER GUIDANCE. THE
MULTI-DAY ONGOING WPC CONTINUITY CONTINUED TO OFFER THE BEST
MIDDLE GROUND SOLUTION. THIS WAS USED THROUGH MON/D6. HOW THE
EASTERN SYSTEM EVOLVES NEXT SUN/MON IS QUITE UNCERTAIN BUT IT DOES
APPEAR THAT A DEEPER SFC LOW MAY LIFT THROUGH NEW ENGLAND. WILL
LET THE DAY SHIFT DIGEST THE 00Z/06Z GUIDANCE BEFORE MAKING ANY
CHANGES. AGAIN, A MIDDLE GROUND BETWEEN THE GFS AND ECMWF WAS
PREFERRED.

IN THE WEST, INITIAL SYSTEM SHOULD LIFT NORTHWARD IN THE NORTHEAST
PACIFIC FRI/SAT AND APPROACH THE OR/WA COAST INTO SUNDAY. ENSEMBLE
SPREAD INCREASES WEST OF CALIFORNIA IN THE BASE OF THE TROUGH AS
VORTICITY DIVING DOWN FROM THE NORTH PACIFIC ROUNDS THE BASE ON
MONDAY. THIS SHOULD CARRY A COLD FRONT INTO SOUTHERN CALIFORNIA
BUT THE ECMWF ENSEMBLES BECOME MUCH QUICKER WITH THE TROUGH THAN
THE GFS ENSEMBLES. GIVEN THE LACK OF GOOD CONTINUITY WITH THE
EVOLUTION OF THIS FEATURE, OPTED TO SPLIT THE ENSEMBLE DIFFERENCE
FOR NEXT TUESDAY FOR NOW.


...WEATHER HIGHLIGHTS AND IMPACTS...

FOCUS WILL INITIALLY BE OVER THE HIGH PLAINS INTO THE MIDWEST AND
GREAT LAKES WITH RAIN IN THE WARM SECTOR AND SNOW TO THE NORTH AND
NORTHWEST OF THE SURFACE LOW. THOUGH PLACEMENT OF THE HEAVIEST
SNOW WILL CONTINUE TO WAVER, WIDESPREAD LIGHT TO MODEST AMOUNTS
ARE PROBABLE WITH SOME AREAS PERHAPS EXCEEDING A FOOT. MARGINAL
TEMPERATURES AND SNOW-TO-LIQUID RATIOS MAY AFFECT HOW MUCH SNOW
CAN ACCUMULATE. ALONG/AHEAD OF THE COLD FRONT, RAIN WILL BREAK OUT
NEAR AND EAST OF THE MISSISSIPPI VALLEY ONCE SOME LIMITED GULF
MOISTURE GETS TAPPED. THIS WILL THEN SPREAD INTO THE OH/TN VALLEY
AND CENTRAL APPALACHIANS THIS WEEKEND AND FINALLY INTO THE
NORTHEAST/MID-ATLANTIC AS THE UPPER TROUGH DIGS THROUGH THE
NORTHEAST, SUPPORTING A NEW SURFACE LOW. COLD AIR WRAPPING AROUND
THE SFC LOW OVER THE RELATIVELY WARM GREAT LAKES SHOULD SUPPORT
SOME LAKE-ENHANCED PRECIPITATION THIS WEEKEND INTO NEXT MONDAY.
TROUGHING JUST OFF THE WEST COAST SHOULD KEEP THE PRECIPITATION
AIMED AT NORTHERN CALIFORNIA AND POINTS NORTHWARD THIS WEEKEND.
DEPENDING ON HOW THE NEXT SYSTEM DEVELOPS FATHER SOUTH,
PRECIPITATION COULD SPREAD THROUGH SOUTHERN CALIFORNIA AND INTO
THE FOUR CORNERS REGION EARLY NEXT WEEK.

VERY WARM TEMPERATURES AHEAD OF THE EMERGING PLAINS STORM WILL
SLOWLY BE REPLACED BY NEAR TO BELOW AVERAGE TEMPS (BY ABOUT 5-15F)
THROUGH THE PERIOD, WHICH WILL LIKELY BE THE COLDEST AIR OF THE
SEASON FOR MANY, INCLUDING FLORIDA AND SOUTH TEXAS. THE
WEST/ROCKIES WILL SEE A WARMING TREND AS UPPER RIDGING MOVES IN
STARTING THIS WEEKEND, PUSHING TOWARD THE PLAINS BY NEXT TUESDAY. 


FRACASSO