874 
FXUS61 KRLX 022022
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
422 PM EDT FRI NOV 2 2012

.SYNOPSIS...
SOME LIGHT PRECIPITATION COULD LINGER IN THE MOUNTAINS TONIGHT. A 
LOW PRESSURE CENTER PASSES TO THE SOUTH LATE SATURDAY AND SATURDAY 
NIGHT. A SYSTEM PASSES SOUTH AND EAST OF THE REGION FOR MID WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AT THE BEGINNING OF THE PERIOD THE UPPER 500MB LOW PROGGED TO BE 
LOCATED OFF THE SOUTHERN NEW ENGLAND COAST WITH NW FLOW ALOFT OVER 
THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BE NOSING IN FROM THE 
NORTHWEST. GOOD FORCING FOR SUBSIDENCE WILL CONTINUE OVER THE AREA 
TONIGHT ON THE BACKSIDE OF THE UPPER LOW. DESPITE THIS...WILL RAMP 
UP POPS AGAIN TO LOW/MID CHANCE DURING THE OVERNIGHT/EARLY MORNING 
HOURS IN THE EASTERN HIGH TERRAIN MAINLY WEBSTER COUNTY AND POINTS 
NORTHEAST WITH FAVORABLE UPSLOPE CONDITIONS AND TRAPPED LLVL 
MOISTURE IN PLACE. DO HAVE A CONCERN HOWEVER WITH FREEZING 
DRIZZLE/MIST IN THOSE AREAS. NAM/GFS/SREF SOUNDINGS ARE ALL DRY AT 
-10C WITH GOOD SATURATION ONLY EXTENDING TO ABOUT -7C TO -8C AND SFC 
TEMPS WELL BELOW FREEZING. TOUGH CALL ON THIS REGARDING PRECIP TYPE 
HOWEVER AS OFTENTIMES IT SEEMS SOUNDINGS IN THIS AREA WOULD INDICATE 
FREEZING DRIZZLE YET SNOW IS STILL THE RESULT. QPF AMOUNTS ARE IN 
THE TWO TO FIVE HUNDREDTHS ROUGHLY. WILL LEAVE ANY ICE ACCUM OUT OF 
GRIDS FOR NOW AND LET EVENING SHIFT TAKE ANOTHER LOOK WITH 
SUBSEQUENT DATA.

PRECIP SHOULD QUICKLY WIND DOWN DURING THE MORNING HOURS ACROSS THE 
HIGH TERRAIN. HEIGHTS INITIALLY RISE DURING THE MORNING HOURS AS 
UPPER LOW CONTINUES AWAY FROM AREA BUT ANOTHER S/W TROUGH DIGGING 
THROUGH THE CENTRAL MISS VALLEY ESSENTIALLY TURNING THE FLOW FROM NW 
DURING THE MORNING TO ZONAL BY END OF PERIOD. A WARM FRONT WILL 
EXTEND EASTWARD FROM SFC LOW OVER WEST/CENTRAL TENN TO AROUND THE 
NC/VA BORDER BY LATE AFT SATURDAY. SOME WEAK ISENTROPIC LIFT IS 
NOTED ON 300K-305K SFCS WELL ABOVE AGL AND THE SOUNDING IS VERY 
WEAKLY CONVECTIVE.  BUT AS PREV FCST NOTED...MUCH OF THE FORCING IS 
FRONTOGENETIC IN NATURE AND FLOW AT H85 AND H7 ESSENTIALLY PARALLEL 
TO WARM FRONT...SO NOT REALLY AN OVERRUNNING SCENARIO. ELECTED TO 
SLOW DOWN POPS JUST A TAD BUT PREV FCST STILL HAD A GENERAL GOOD 
HANDLE ON PRECIP MOVING INTO THE SW ZONES BY END OF PERIOD.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
LOW PRESSURE PASSES S OF THE AREA THIS WEEKEND.  ASSOCIATED WARM 
ADVECTION AND ISENTROPIC LIFT SPREADS PRECIPITATION INTO SOUTHERN 
PORTION OF THE AREA LATE SAT OR SAT EVENING DEPENDING UPON HOW LONG 
IT TAKES TO MOISTEN THE LOW LEVELS.  EXPECT PRECIPITATION TO BE 
LIGHT GIVEN VERY ACUTE ANGLE ON PRESSURE ADVECTION ON THE 295 AND 
300 K ISENTROPIC SURFACES.  MAINLY A RAIN EVENT GIVEN THERMAL 
FIELDS.  EVEN WHERE NEAR 0C AT H85...THERE IS NO MECHANISM TO GET 
SURFACE TEMPERATURES DOWN TO FREEZING ACROSS LOWLANDS.  SOME SNOW IS 
POSSIBLE HIGH TERRAIN OF CENTRAL MOUNTAINS SAT NT BUT HAVE LOW 
CHANCE THERE ON NORTHERN EDGE OF SYSTEM.

SYSTEM PULLS AWAY SUN BUT UPPER LEVEL S/W TROUGH WILL LIKELY KEEP 
SOME CLOUDS AROUND.  THIS FEATURE EXITS FIRST THING MON 
MORNING...ALLOWING HIGH PRESSURE TO PROVIDE FOR A NICE START TO THE 
NEW WORK WEEK.

WITH PRECIPITATION HYDROLOGICALLY INSIGNIFICANT...LOWS IN THE 20S TO 
AROUND FREEZING AND HIGHS IN THE 40S WHERE THE HIGH TERRAIN SNOW 
PACK IS...THE SLOW MELT CONTINUES...WITH NOTHING MORE THAN 
LOCALIZED SMALL STREAM AND CREEK ISSUES WHERE STORM DEBRIS CREATES 
BLOCKAGES.  IT LOOKS LIKE SWE VALUES IN THE SNOW PACK ARE DOWN TO 
THE TWO TO FOUR INCH RANGE.

BLENDED IN BIAS CORRECTED ADJMET ON TEMPERATURES EARLY ON AND THEN 
BIAS CORRECTED CONSALL - OVERALL NO MAJOR CHANGES INVOLVED.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
USED A BLEND OF THE ECMWF AND ECMWF ENSEMBLE MEAN FOR THIS PERIOD. 
THIS WOULD HAVE A STORM SYSTEM SOUTH AND EAST OF THE REGION POSSIBLY 
GRAZING THE AREA FOR MID WEEK. A WARM FRONT WOULD THEN PUSH 
NORTHWARD TOWARD THE END OF THE WEEK.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
18Z FRIDAY THRU 18Z SATURDAY...GENERAL VFR CONDITIONS EXPECTED
ACROSS THE AREA FOR THE VALID PERIOD. THE ONLY EXCEPTION TO THIS
WILL BE EKN...WHERE UPSLOPE FLOW AND TRAPPED LLVL MOISTURE SHOULD BE
ENOUGH TO WRING OUT A SOLID MVFR/IFR CLOUD DECK WITH SOME LIGHT
MIXED PRECIP IN THE AREA. THIS SHOULD DISSIPATE DURING THE MORNING
HOURS. OTHERWISE...A WEST/NORTHWEST WIND WILL CONTINUE THROUGH THE
PERIOD AROUND 5 TO 10KTS OVERNIGHT...WITH GUSTS TO AROUND THE
15-20KT RANGE BOTH THIS AFTERNOON AND LATE MORNING SAT.


FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
          
FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: TIMING OF CIG HEIGHTS AND PRECIP CONDITIONS
AT EKN MAY VARY.

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.

UTC 1HRLY       20   21   22   23   00   01   02   03   04   05   06   07
EDT 1HRLY       16   17   18   19   20   21   22   23   00   01   02   03
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    M    M    M    M    L    L    L
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 18Z SATURDAY...
NO WIDESPREAD IFR EXPECTED.

&&

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

&&

$$
SYNOPSIS...TRM/RPY/50
NEAR TERM...50
SHORT TERM...TRM
LONG TERM...RPY
AVIATION...50