Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 230012
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
712 PM EST SAT NOV 22 2014

.SYNOPSIS...
LOW PRESSURE APPROACHES FROM THE SOUTHWEST OVERNIGHT AND
SUNDAY...AND PASSES WEST OF THE AREA SUNDAY NIGHT.  A STRONG COLD
FRONT WHIPS THROUGH ON MONDAY.  CHILLY HIGH PRESSURE TUESDAY NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
700 PM UPDATE...
NO SIGNIFICANT CHANGES NEEDED.

PREV DISCN...
JUST A FEW RAIN SHOWERS STILL LINGERING ACROSS NORTHERN CWA...BUT
MOISTURE IS PULLING AWAY TO THE NORTH AND EXPECT THESE TO DRIFT
NORTH AND TAPER OFF EARLY THIS AFTERNOON. THE STRATUS DECK IS EVEN
BREAKING UP ACROSS SOUTHERN OH AND NORTHERN KY. WARM AIR ADVECTION
IS FINALLY KICKING IN AND HAVE RAISED TODAYS HIGHS A GOOD DEAL...AND
MAY NOT BE HIGH ENOUGH YET. AFTER A BRIEF DRIER PERIOD TONIGHT INTO
SUNDAY MORNING...MOISTURE REALLY INCREASES FROM THE SOUTH AS THE
NEXT SYSTEM APPROACHES. HAVE POPS INCREASING FROM THE SOUTH THROUGH
THE DAY SUNDAY.

STRONG WINDS JUST OFF THE SURFACE TOMORROW...WITH GFS SHOWING UP
TO 80 KTS AT 850MB. ADD IN SOME DOWNSLOPING WITH THE EASTERLY
FLOW...AND EXPECT A VERY BREEZY AFTERNOON SUNDAY...ESPECIALLY FOR
THE HIGHER TERRAIN AND WESTERN SLOPES. DO NOT HAVE HIGH ENOUGH
WINDS FOR AN ADVISORY AT THIS POINT...BUT WILL NEED TO KEEP
WATCHING THIS. ALSO TRIED TO GO WITH LOWER POPS IN THE DRY
DOWNSLOPING REGION. HOLDING OFF ON LIKELY POPS FOR THOSE AREA
UNTIL SUNDAY EVENING.

INCREASED BOTH LOWS AND HIGHS. BLENDED MET INTO THE LOWS...AND
USED A CONSENSUS BLEND FOR HIGHS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AN APPROACHING LOW PRESSURE SYSTEM WILL LIFT FROM THE MISSISSIPPI
VALLEY...NORTH NORTHEAST INTO THE OH VALLEY AND WV SUNDAY AND
MONDAY. MODELS INDICATE WIND FLOW WILL TURN DEEP FROM THE SOUTH
SOUTHWEST...TO BRING MOIST AND WARM AIR MASS ON SUNDAY. A WARM
FRONT WILL MERGE FROM THIS FLOW TO PRODUCE AREAS OF RAIN SPREADING
FROM SOUTH TO NORTH.

WIND FLOW WILL INCREASE BY 00Z MONDAY...AS SUGGESTED BY H850 WINDS
FROM THE GFS/ECMWF OF ABOUT 65-70 KNOTS. UNDER ISENTROPIC
UP GLIDING...IT WILL BE MORE LIKELY FOR SOME OF THESE WINDS TO
CREATE GUSTY CONDITIONS OVER HIGHER ELEVATIONS.

AN ASSOCIATED COLD FRONT WILL CROSS WEST TO EAST EARLY MONDAY. WITH
H850 TEMPERATURES AROUND 10C...EXPECT ALL PCPN TO FALL AS LIQUID.
THEREFORE...EXPECT ROUNDS OF SCATTERED TO NUMEROUS RAIN SHOWERS. PW
AROUND 1.25 INCHES AND STRONG DEEP LAYERED SHEAR COULD PRODUCE A LOW
CHANCE FOR THUNDER...BUT WILL KEEP MENTION OUT OF FORECAST. COLDER
AIR RUSHES IN BEHIND THE COLD FRONT DROPPING TO MINUS 6C BY 06
TUESDAY.

WENT CLOSE TO PREVIOUS TEMPERATURES...PERHAPS A LITTLE WARMER
SUNDAY INTO MONDAY DUE TO STRONG DEEP SOUTH SOUTHWESTERLY FLOW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WE HAVE LOW CONFIDENCE IN THE DETAILS FOR THE LONG TERM AS FAST FLOW
ALOFT DOMINATES.  THIS INCLUDES SEVERAL ELEMENTS NOT JUST
POPS...INCLUDING CLOUDS AND TEMPERATURE.  GENERALLY WENT A BIT
COLDER THAN WPC MEDIUM RANGE GUIDANCE AND A BIT MORE LIBERAL ON
CHANCE POPS FOR SNOW SHOWERS.

AT THE START OF EXTENDED...THINKING LEFTOVER STRATOCUMULUS LOW
LEVEL MOISTURE FROM THE DAY ON TUESDAY...ESPECIALLY ACROSS THE
NORTH...SHOULD BE DRYING UP/THINNING TUESDAY EVENING.

WITH THE MEAN MID/UPPER LEVEL TROF STILL TO OUR WEST...ECMWF MOST
AGGRESSIVE KINKING THE MID LEVEL MOISTURE BACK WEST FOR WEDNESDAY.
CAN NOT GO THAT FAR WEST...WILL TREND MORE TOWARD THE GFS AND CMC
AND HAVE JUST CHANCE POPS FOR WEDNESDAY FOR MOSTLY LIGHT SNOW MAINLY
12Z TO 16Z WEDNESDAY SOME EASTERN MOUNTAIN COUNTIES.

IN THE WAKE OF THAT EAST COAST SYSTEM...DISTURBANCES IN THE FAST
WEST AND NORTHWEST FLOW ALOFT DOMINATE AROUND THANKSGIVING INTO
FRIDAY NIGHT. GFS SOLUTION HAS 850 MB TEMPERATURES WARMING UP
THURSDAY...AHEAD OF ONE OF THOSE SYSTEMS.  MEANWHILE...ECMWF MUCH
COLDER.  DID NOT GO AS COLD AS THE ECMWF.

THINK COLDEST 850 MB AIR SHOULD BE OVER US FRIDAY.  WILL INCLUDE
SOME 20 TO 30 POPS FOR SNOW SHOWERS ACROSS NORTHERN COUNTIES FRIDAY
AND FRIDAY NIGHT.

DEEPER MOISTURE MAY START RETURNING BY END OF EXTENDED...OVERNIGHT
SATURDAY NIGHT.

OVERALL...NO MAJOR STORMS...BUT THE FINER DETAILS STILL HARD TO TIME.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AFTER A VFR NT WITH JUST ENOUGH WIND TO PRECLUDE FOG...CLOUDS
INCREASE SUNDAY...IN ADVANCE OF A LARGE AND COMPLEX LOW PRESSURE
SYSTEM APPROACHING FROM THE S AND W...WITH RAIN ARRIVING FROM THE S
BY LATE SUNDAY.  RAIN WILL BRING CIGS DOWN TO AROUND 5KFT BUT MVFR
VSBY POSSIBLE BY THE END OF THE PERIOD SRN SITES.  EXCEPTION IS BKW
WHERE SE FLOW WILL BECOME QUITE GUSTY...POTENTIALLY UP TO AROUND 30
KTS BY THE END OF THE PERIOD.   THESE STRONG SE WINDS WILL BRING
CIGS DOWN TO NEAR THE IFR THRESHOLD BY THE END OF THE PERIOD.

LIGHT S TO SE SFC FLOW OVERNIGHT WILL BECOME SE ON SUNDAY AND
STRENGTHEN...BECOMING GUSTY SRN SITES BUT QUITE STRONG AND GUSTY ON
THE RIDGES OF THE WV MOUNTAINS.  MODERATE SW FLOW ALOFT WILL BECOME
LIGHT S SUNDAY MORNING AND THEN MODERATE S SUNDAY AFTERNOON.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...

FORECAST CONFIDENCE: HIGH...DECREASING LATE.

ALTERNATE SCENARIOS: TIMING OF RAIN AND ASSOCIATED MVFR VSBY LATE
SUNDAY COULD VARY.  LOW CIGS AND STRONG WINDS AT BKW SUNDAY
AFTERNOON COULD 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.

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 POSSIBLE ON EASTERN MOUNTAIN SLOPES AND ACROSS THE MIDDLE OHIO
VALLEY IN RAIN AND STRATUS SUNDAY NT INTO MON MORNING.

&&

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

&&

$$
SYNOPSIS...TRM
NEAR TERM...TRM/MZ
SHORT TERM...ARJ
LONG TERM...LS
AVIATION...TRM





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