-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 302322
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
622 PM EST SAT NOV 30 2013

.SYNOPSIS...
HIGH PRESSURE EXITS SUNDAY.  WARMING TREND STUNTED BY WEAK SYSTEM
MONDAY...BUT RESUMES MID WEEK AHEAD OF A LARGER SYSTEM.  THAT SYSTEM
SLOWLY CROSSES LATE WEEK AS A WAVY COLD FRONT.  COLDER SATURDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
-- Changed Discussion --
OVERALL TRANQUIL WEATHER UNDER HIGH PRESSURE WITH LIGHT SOUTHEASTERLY
FLOW ACROSS THE REGION. CLEAR SKIES ACROSS THE REGION OVERNIGHT
WITH CLOUD COVER BEGINNING TO INCREASE TOWARDS MORNING AHEAD OF AN
APPROACHING COLD FRONT. OVERNIGHT LOW TEMPS SLIGHTLY WARMER
ACROSS THE NORTH WHERE INCREASED CLOUD COVER IS POSSIBLE...WITH
COOLER TEMPERATURES ACROSS EASTERN ZONES.

COLD FRONT WILL BE ACROSS NORTHERN OHIO SUNDAY AFTERNOON...GIVINGA
SLIGHT CHANCE FOR POPS ACROSS SOUTHEAST OHIO ZONES. FORECAST
SOUNDINGS LOOK PRETTY DRY AT MID AND UPPER LAYERS OF
ATMOSPHERE...SO NOT EXPECTING MUCH OUTSIDE OF A LIGHT SHOWER OR
SPRINKLE.
-- End Changed Discussion --

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
A FAIRLY UNSETTLED PATTERN ENSUES IN THE SHORT TERM...YET WITH FEW
NOTABLE IMPACTS. SUNDAY NIGHT AND MONDAY FLOW BACKS FROM ZONAL
INITIALLY TO SOUTHWESTERLY BY MON AFT AS AN UPPER TROUGH PROGRESSES
EASTWARD ACROSS THE CENTRAL CONUS...PROGGED TO BE LOCATED OVER THE
WESTERN GREAT LAKES SOUTHWARD INTO THE LOWER OHIO RIVER VALLEY BY
00Z TUE. MONDAY NIGHT...A COLD FRONT WILL APPROACH THE NW ZONES BUT
BECOME QUASI-STATIONARY...ALONG WITH A QUICK-MOVING S/W TROUGH WHICH
WILL PASS PRIMARILY TO THE NORTH OF THE FORECAST AREA. DEEP LAYER
MOISTURE IS LACKING BUT WITH NEAR-SATURATED LLVLS UP TO ABOUT 4-6KFT
AGL...WILL CARRY A SLIGHT CHANCE OF LIGHT RAIN SHOWERS FOR CENTRAL
AND NORTHERN ZONES OVERNIGHT AND EARLY MON MORNING WITH THESE
FEATURES. SFC TEMPS...WITH SLIGHTLY WARMER AIR JUST
OFF-SFC...EXPECTED TO KEEP PRECIP TYPE ALL RAIN FOR ALL LOWLAND
LOCATIONS. THE EASTERN HIGH TERRAIN WILL BE COLD ENOUGH TO SEE SOME
SNOW AND/OR A WINTRY MIX...WITH MOISTURE ONLY REACHING UP TO ABOUT
THE -5C TO -6C RANGE. WHETHER IT BE LIQUID OR FROZEN...ACCUMULATIONS
WILL BE ON THE LIGHT SIDE.

MONDAY...WILL PROBABLY SEE A LULL IN PRECIP FOR THE LATE MORNING AND
AFTERNOON HOURS AS THE FIRST S/W TROUGH CONTINUES OFF TO THE
NORTHEAST...WITH THE AFOREMENTIONED MORE STOUT UPPER TROUGH PUSHES
TOWARD THE AREA FROM THE WEST. SFC FRONT STILL REMAINS HUNG UP
ACROSS CENTRAL OHIO IT APPEARS IN RESPONSE TO SFC LOW TO THE
SOUTHWEST. SKIES DO HOWEVER REMAIN MOSTLY CLOUDY THROUGHOUT THE
DAY...WHICH MAKE MAX TEMPS TRICKY. LATEST MOS GUIDE ALONG WITH
PROGGED 850MB/925MB TEMPS MONDAY AFT DEPICT SFC LOWLAND TEMPS UP TO
AROUND 50F. WON/T COMPLETELY BUY INTO THOSE NUMBERS WITH THE CLOUD
DECK EXPECTED...YET WITH LITTLE PRECIP EXPECTED DURING THE PM HOURS
WILL NUDGE MAX TEMPS UPWARD SOME GENERALLY INTO THE MID/UPPER 40S
YET CONTINUE TO REMAIN BELOW GUIDANCE CONSENSUS.

MONDAY NIGHT AND TUESDAY...THE UPPER TROUGH PROGRESSES EASTWARD
THROUGH THE FORECAST AREA. LATEST NAM IS GENERALLY THE SLOWER
SOLUTION...WITH TROUGH AXIS LOCATED OVER THE EASTERN MOUNTAINS BY
12Z TUE. SREF MEAN AND OP GFS ARE EVEN QUICKER. EVEN WITH THE SLOWER
NAM SOLUTION...EVEN LESS LLVL MOISTURE APPEARS TO BE ADVECTED INTO
OUR AREA VERSUS SUNDAY NIGHT/S NORTHERN SYSTEM...WITH THE BULK OF
THE HIGHER MOISTURE CONTENT REMAINING SOUTH/EAST OF OUR AREA. AS
SUCH...WILL ONLY CARRY A SLIGHT CHANCE OF PRECIP MONDAY NIGHT INTO
EARLY TUESDAY. AND AS WITH THE PREVIOUS NIGHT...OVERNIGHT LOWS
REMAIN WARM ENOUGH FOR RAIN ACROSS THE LOWLANDS WITH WINTRY PRECIP
IN THE EASTERN MOUNTAINS...AND ONLY LIGHT ACCUMULATIONS ARE
EXPECTED. SFC FRONT MEANWHILE ATTEMPTS TO PUSH SOUTHWARD INTO AREA
BUT QUICKLY WASHES OUT AND REALLY NEVER MAKES INROADS INTO THE AREA.
WITH THE DEPARTING UPPER TROUGH ON TUESDAY...SKIES WILL REMAIN
MOSTLY CLOUDY FOR THE MOST PART WITH PERHAPS SOME LATE DAY PEAKS OF
SUN FOR THE LOWLANDS. DEPENDING UPON MODEL OF CHOICE...BOTH LATEST
NAM12 AND 12Z EC DEPICT 925MB TEMPS OF ABOUT 6C...WHICH WOULD
SUPPORT LOWLAND TEMPS OF ABOUT 55F. MOS GUIDANCE ALSO TRENDING
WARMER AS WELL. NOT QUITE WILLING TO GO ALL THE WAY TO THE MID 50S
WITH AFOREMENTIONED CLOUD COVER...BUT WILL BUMP MAX TEMPS UPWARD TO
ABOUT THE 50F DEGREE MARK FOR THE CRW-HTS CORRIDOR SOUTHWARD INTO
THE COALFIELDS AND MID/UPPER 40S FOR NORTHERN LOWLANDS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MAIN FEATURE THIS PERIOD IS A WAVY COLD FRONT THAT CROSSES THE AREA
AS A LARGE BUT PROGRESSIVE TROUGH THE MIDDLE CONUS.

GFS HAS A LEAD UPPER LEVEL LOW THAT LIFTS THROUGH THE UPPER GREAT
LAKES TUE NT AND WED WHICH THE OTHER MODELS DO NOT HAVE.  THE GFS
USES THIS FEATURE...AND ITS SFC REFLECTION...TO PUSH A COLD FRONT
INTO THE AREA WED...GIVING RISE TO RAIN SHOWERS.  OTHER MODELS HAVE
UPPER LEVEL RIDGING CROSSING THE AREA WED AFTERNOON AND
EVENING...WHICH WOULD KEEP THE WEATHER DRY THROUGH THEN AND THIS IS
IN LINE WITH WPC THINKING.

THE WPC/CMC/ECMWF SCENARIO THEN BRINGS THE COLD FRONT TOWARD THE
AREA THU...BEFORE BEING HELD UP INTO FRI BY WAVES OF LOW PRESSURE
MOVING UP ALONG IT...BENEATH THE BROAD SW FLOW ALOFT OUT AHEAD OF
THE LARGE MID CONUS TROUGH.  THIS INTRODUCES THE CHANCE FOR RAIN
SHOWERS LATE WED NT...THE CHANCE INCREASING THU TO HIGH CHANCE /
LIKELY FOR THU NT THROUGH FRI.  THIS CAPTURES THE TIME THE MAIN
CORRIDOR OF PRECIPITATION SHOULD BE OVER OR NEARLY OVER THE FCST
AREA...WHILE NOT ATTEMPTING TO TIME ANY INDIVIDUAL WAVES AT THIS
DISTANCE.

INCLUDED THE SLIGHT CHANCE FOR THUNDER FOR MAINLY THE MOUNTAINS
AHEAD OF THE FRONT LATE THU GIVEN HIGHER DEW POINTS AND STRONG FLOW.

THE FRONT PUSHES S AND E OF THE AREA FRI NT...WITH POPS GRADUALLY
WANING FRI NT AND SAT.  AN UNDERCUTTING PATTERN IS LIKELY BEHIND THE
FRONT WITH ADDITIONAL WAVES NOT OUT OF THE QUESTION.  WE MAY NEED TO
KEEP A WATCHFUL EYE ON THE LENGTH OF TIME THIS SYSTEM IS TO IMPACT
OUR AREA PER RAINFALL TOTALS...ALTHOUGH THESE WINDOWS DO TEND TO
NARROW AS THE TIME GETS CLOSER.

BLENDED IN BIAS CORRECTED VERSIONS OF THE ECMWFHIRES AND ADJMEX...AS
WELL AS WPC FOR TEMPERATURES.  HAVE IT MILDER AHEAD OF THE SYSTEM
WED AND THU...WITH A TIGHTER BAROCLINIC ZONE REFLECTED IN FCST HIGHS
FOR FRI.  COLDER...DRIER AIR SHOULD SET IN BY THE END OF THE PERIOD
/SUN MORNING/.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
VFR CONDITIONS WITH LIGHT SOUTHEASTERLY SURFACE WINDS THROUGH 06Z SUNDAY.
MID AND HIGH CLOUDS GRADUALLY INCREASE AFTER 06Z SUNDAY ACROSS
SOUTHEAST OHIO AND EASTERN KY. FLOW TURNS MORE SOUTHWESTERLY AFTER
12Z SUNDAY...BUT WINDS WILL REMAIN LIGHT.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
LIGHT PRECIPITATION MAY ARRIVE EARLIER THAN EXPECTED TOWARDS THE
END OF THE TAF PERIOD.

FORECAST CONFIDENCE: HIGH.

ALTERNATE SCENARIOS: NONE.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                                                 SUN
UTC 1HRLY       00   01   02   03   04   05   06   07   08   09   10   11
EST 1HRLY       19   20   21   22   23   00   01   02   03   04   05   06
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 00Z MONDAY...
IFR CIGS POSSIBLE SUNDAY NIGHT INTO MONDAY...MAINLY ACROSS MOUNTAINS.
-- End Changed Discussion --

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...TRM/50/SL
NEAR TERM...JW
SHORT TERM...50
LONG TERM...TRM
AVIATION...SL