Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 061046
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
546 AM EST SAT FEB 6 2016

.SYNOPSIS...
HIGH PRESSURE BUILDS INTO SUNDAY...WITH A TRANQUIL FEBRUARY
ENVIRONMENT. COLD FRONT MONDAY. UNSETTLED/COLDER TUESDAY AND
WEDNESDAY UNDER MID/UPPER LEVEL LOW...WITH ROUNDS OF SNOW SHOWERS.

&&

.NEAR TERM /THROUGH TONIGHT/...
A SFC HIGH PRESSURE REMAINS IN CONTROL WITH DRY AND COOL WEATHER.
SATELLITE IMAGES AND SFC OBS SHOW HIGH LEVEL CLOUDS MOVING
NORTHEAST ACROSS THE AREA. EXPECT THESE CLOUDS TO CONTINUE
COVERING THE SKIES THROUGH TONIGHT.

TEMPERATURES WILL BE NEAR NORMAL. GENERALLY IN THE MID 40S
LOWLANDS TO UPPER 30S HIGHEST ELEVATIONS FOR HIGHS. LOWS WILL
DEPEND ON CLOUD COVER TONIGHT. SINCE EXPECTING MOSTLY CLEAR
SKIES...LIGHT AND VARIABLE TO CALM WINDS AFTER THE LOWER
ATMOSPHERE DECOUPLES...TEMPERATURES WILL DROP INTO THE MID TO
UPPER 20S.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SIGNIFICANT CHANGES IN AIRMASS AND PRECIPITATION CHARACTERIZE THE
SHORT TERM FORECAST WITH A WELL ADVERTISED UPPER LEVEL LOW DIVING
INTO THE SOUTHERN GREAT LAKES FROM THE UPPER MISSISSIPPI VALLEY.
SINCE THE OPERATIONAL NAM/GFS/ECMWF ARE IN FAIRLY GOOD
AGREEMENT...RELIED ON THE NAM FOR THE DETAILS FOR THE UPPER LEVEL
SYSTEM AND THE SURFACE SYSTEM COUNTERPART AS THEY TRAVERSE THE OHIO
VALLEY/CENTRAL APPALACHIANS.

INITIAL BAND OF SHOWERS EXPECTED WITH THE FRONT...AND ONCE
AGAIN...HAVE USED LOW TO MID LEVEL DEFORMATION TO TIME THE ARRIVAL
AND PASSAGE OF THIS FEATURE. EXPECTING A SLIVER OF DRY AIR BEHIND
THE COLD FRONT...AND TRIED TO REPRESENT THIS IN A MARKED DECREASE IN
CLOUD COVER AND DROPPING POPS TO SLIGHT CHANCE. TIMING OF THIS IS
ALWAYS TRICKY...HOWEVER. SHOULD BE COMPLETELY RESATURATED IN THE
LOWER LEVELS ACROSS THE ENTIRE CWA BY 06Z TUESDAY IN THE COLD AIR
ADVECTION. HAVE SNOW CHANCES INCREASING EARLY MONDAY NIGHT INTO THE
LIKELY/CATEGORICAL THROUGH MUCH OF TUESDAY...BUT THIS IS MORE OF AN
AUTOCONVECTIVE SCENARIO AS OPPOSED TO AN UPSLOPE CONDITION DUE TO THE
1000-850MB STREAMLINES THAT ARE MORE WESTERLY THAN
NORTHWESTERLY/PERPENDICULAR TO THE MOUNTAINS. NOT DISCOUNTING THE
TERRAIN INFLUENCES COMPLETELY THOUGH. 850MB TEMPERATURES DROP INTO
THE LOWER MINUS TEENS MONDAY NIGHT THROUGH TUESDAY.

DUE TO THE TIMING...EXPECT VERY LITTLE TEMPERATURE RECOVERY MONDAY
WITH THE FRONTAL PASSAGE DURING THE DAY. ALSO...HAVE TAKEN THE MAX
TEMPERATURES FOR TUESDAY DOWN FROM THE GUIDANCE NUMBERS A FEW
NOTCHES...WITH THE THINKING THAT ABOVE FREEZING VALUES WILL NOT BE A
GOOD PLAY HERE. GUIDANCE TENDS TO OVERPLAY THESE SITUATIONS AND HAVE
THE AREA TOO WARM...SO WILL KEEP IT COLD AREA WIDE.

FOR AMOUNTS...NOT TOO MANY CHANGES IN SNOW FROM THE PREVIOUS
FORECAST. DESPITE IT NOT BEING A PERFECT UPSLOPE SITUATION AS
PREVIOUSLY MENTIONED...THINK THERE WILL BE BETTER ENHANCEMENT OF THE
SNOWFALL IN THE HIGHER ELEVATIONS. BUT FOR THE MOST PART...THIS WILL
BE A SLOW ACCUMULATION OF SNOW OVER TIME IN OFF AND ON SNOW SHOWERS
AND SQUALLS OVER THE LOWLANDS. AS FAR AS FUTURE HEADLINE
CONSIDERATIONS GOES...A LOT WILL DEPEND ON DURATION/HOW LONG IT
TAKES TO GET THE ACCUMULATIONS...WHICH AS OF RIGHT NOW...SPANS
WELL INTO DOUBLE DIGIT HOURS. HWO WILL BE HIGHLIGHTED AS SUCH.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AFTER THE INITIAL SUPPORT SWINGS THROUGH ON MONDAY...POPS INCREASE
AGAIN MONDAY NIGHT...WITH UPPER/MID LEVEL LOW DROPPING INTO OHIO
AND SURFACE LOW TRYING TO TAKE SHAPE TOWARD DELMARVA.

GFS AND ECMWF SIMILAR NOW...WITH 500 MID LEVEL LOW IN OUR VCNTY
AROUND 18Z TUESDAY. OLD SOLUTIONS OVER THE PAST FEW DAYS...OF MID
LEVEL LOW GOING TO OUR SOUTH...SEEMS LESS LIKELY NOW.  WEAKENING 500
MB TROF REMAINS IN VICINITY INTO WEDNESDAY...WITH THE COLDER 850 MB
TEMPS STILL ADVECTING IN ON WEDNESDAY.  HAVE MIN TEMPS NEAR ZERO
AOB 4 THSD FT WEDNESDAY NIGHT. ONLY APPARENT TEMPS AT WIND
CHILL ADVISORY ALSO MOSTLY AOA 4 THSD FT.  SO NOT WORTH HIGHLIGHTING
IN THE HAZARDOUS WEATHER POTENTIAL.

ROUNDS OF SNOW SHOWERS STILL EXPECTED MONDAY NIGHT INTO WEDNESDAY.
ALSO STILL TRIED TO KEEP OUR POPS HIGHER THAN GUIDANCE IN THE MOIST LOW
LEVEL THERMAL TROF AND MOISTURE DEPTH STILL UP TO 10 THSD FT.

PICTURING AT THIS DISTANCE IN TIME...A LOT OF 1 TO 3 INCHES OF SNOW
IN LOWLANDS OVER 12 HOURS...AND 2 TO 4 INCHES OVR MOUNTAIN COUNTIES
MONDAY NIGHT INTO TUESDAY NIGHT. SO THINKING MORE TOWARD WINTER WEATHER
ADVISORIES THAN TAKING THE WINTER STORM WATCH/WARNING AVENUE. OF
COURSE...OVER 48 HOURS AMOUNTS WILL ADD UP OVER THE MOUNTAINS. WILL
INCLUDE IN HAZARDOUS WEATHER POTENTIAL.

LOW CONFIDENCE FOR DAY 6 AND 7...IN THE 100+ KNOT 250 MB FLOW FROM THE
WEST NORTHWEST. COULD EASILY SEE SOME CLIPPER ACTION...BUT
UNCERTAINTY IS IN THE TIMING. INCLUDED 20 POPS FOR NOW FOR
THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
SFC HIGH PRESSURE WILL PROVIDE DRY WEATHER...WITH LIGHT
SOUTHERLY WINDS THROUGH THE PERIOD. DESPITE OF A DRY
ATMOSPHERE...HIGH CIRRUS CLOUDS WILL BE COMMON SATURDAY.

VFR CONDITIONS WILL PREVAIL AS A SFC HIGH PRESSURE REMAINS IN
CONTROL THROUGH SATURDAY NIGHT. BUFKIT SOUNDINGS AND SFC OBS SHOW
A VERY DRY ATMOSPHERE IN THE BOUNDARY LAYER.

SFC FLOW WILL BE LIGHT MAINLY SW TODAY.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...

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               SAT 02/06/16
UTC 1HRLY       10   11   12   13   14   15   16   17   18   19   20   21
EST 1HRLY       05   06   07   08   09   10   11   12   13   14   15   16
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 12Z SUNDAY...
MVFR TO IFR CONDITIONS POSSIBLE IN RAIN/SNOW SHOWERS MONDAY INTO
WEDNESDAY MORNING.

&&

.HYDROLOGY...
THE RIVER GAUGE AT PARKERSBURG...ALONG THE OHIO RIVER...HAS BEEN
FIXED.

&&

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

&&

$$
SYNOPSIS...ARJ/26
NEAR TERM...ARJ
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ

HYDROLOGY...


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