Area Forecast Discussion
Issued by NWS Charleston, WV

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KRLX 200749
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
349 AM EDT SAT SEP 20 2014

.SYNOPSIS...
HIGH PRESSURE MOVING OFF NORTHEAST COAST...ALLOWS SOUTHERLY FLOW TO
BRING WARMER...BUT STILL MAINLY DRY WEATHER TODAY.  A COLD FRONT
CROSSES SUNDAY AFTERNOON.  FALL HIGH PRESSURE DOMINATES NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPSLOPE INDUCED LOW CLOUDS ALONG THE EASTERN SLOPES OF THE WV
MOUNTAINS WERE BEGINNING TO ERODE FROM THE S AND W...A TREND THAT
SHOULD CONTINUE TODAY AS THE FLOW CONTINUES TO VEER THROUGH S.

THIS WARM ADVECTION VEERING WAS ALSO ASSOCIATED WITH A STRATOCU DECK
FORMING TO THE W OF THE AREA IN THE THETA E AXIS.  THIS MAY
EVENTUALLY CONVERT AS SPOTTY SHOWERS W OF HTS LATER THIS MORNING.
MODELS SUGGESTS SPOTTY FRONTOGENETIC FORCING INTO THIS AFTERNOON
RIDING UP THE MIDDLE OHIO VALLEY WITH SUFFICIENT MOISTURE H85-H7 TO
PER HAPS STAND UP A SHOWER...ALTHOUGH NEAR TERM MODELS DO NOT OUTPUT
ANY RAINFALL AMOUNTS.  OTHERWISE WILL HAVE A SCT-BKN CU / STRATOCU
FIELD THIS AFTERNOON.

CLOUDS INCREASE AS A COLD FRONT APPROACHES TONIGHT.  LINE OF
CONVECTION WAS NEARLY CO-LOCATED WITH ASSOCIATED COLD FRONT OVER
THE MIDWEST EARLY THIS MORNING.  HAVE CHC SHRA/TSRA ENTERING THE
AREA FROM THE NW AROUND 06Z AND REACHING THE OHIO RIVER BY 12Z SUN
IN ASSOCIATION WITH THIS FEATURE.  THIS IS CLOSE TO MODELS WHICH
HAVE COME CLOSER TOGETHER FOR THE NEAR TERM PERIOD.  INSTABILITY
BECOMES ELEVATED AS THUNDER ROLLS INTO THE AREA OVERNIGHT TONIGHT.

HIGHS TODAY WERE CLOSER TO STRAIGHT GUIDANCE RATHER THAN THE LOWER
BIAS CORRECTED OUTPUT.  LITTLE CHANGE NEEDED OTHER THAN TO LOWER THE
EASTERN SLOPES A BIT...WITH DOWNSLOPE SRLY FLOW W OF THE MOUNTAINS.
BLENDED IN BIAS CORRECTED MET FOR LOWS TONIGHT AS THE MAV LOOKED TOO
LOW ALL AROUND EVEN WITH A BIT LESS FLOW COMPARED WITH THIS MORNING.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
COLD FRONT ACROSS NORTHWEST OHIO AND CENTRAL INDIANA AT BEGINNING OF
PERIOD...PUSHING EAST THROUGH THE CWA DURING THE DAY SUNDAY...AND TO
THE EAST OF THE HIGHER TERRAIN BY SUNDAY NIGHT. NAM STILL THE SLOWER
OF THE SOLUNS...BUT IS STARTING TO COME INTO BETTER AGREEMENT WITH
FASTER GFS/ECMWF. CONTINUED TO LEAN FORECAST TOWARDS GFS SOLUN.

COULD SEE ISOLATED STRONG WIND GUSTS SUNDAY AFTERNOON...MAINLY
SOUTHEAST OHIO AND NORTHERN WV COUNTIES ON SUNDAY WITH ANY
CONVECTION THAT DEVELOPS. SPC CONTINUES TO MAINTAIN A SEE TEXT OFF
TO OUR NORTHEAST.

UPPER TROUGH WILL SWING THROUGH THE AREA SUNDAY NIGHT/MONDAY...WITH
CLOUDS...AND PERHAPS SOME LIGHT PRECIPITATION OR DRIZZLE LINGERING
ACROSS THE CWA SUNDAY NIGHT INTO MONDAY...PARTICULARLY THE
WV/SOUTHWEST VA ZONES. HELD ONTO CLOUD COVER ACROSS THE
AFOREMENTIONED ZONES INTO MUCH OF THE DAY MONDAY...WITH HIGHER
TERRAIN COUNTIES LAST TO CLEAR.  HIGH PRESSURE WILL BUILD IN FOR
TUESDAY FOR A RETURN TO DRIER WEATHER.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
MODELS SHOWING A FALL HIGH PRESSURE SYSTEM OVER THE REGION THROUGH
THE PERIOD.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
THE AREA WILL BE IN A SRLY FLOW BETWEEN HIGH PRESSURE WELL TO THE
E...AND A COLD FRONT APPROACHING FROM THE W.  THIS WILL KEEP VFR
CONDITIONS FOR THE MOST PART WITH SCT STRATOCU AOA 5 KFT...AND FLOW
JUST STRONG ENOUGH TO PRECLUDE DENSE FOG.

THERE ARE A FEW CAVEATS.

MOISTURE IN S TO E FLOW ALONG THE EASTERN SLOPES COULD STILL GET
INTO BKW AT TIMES INTO SAT MORNING WITH CIGS CLOSE TO 1 KFT EITHER
SIDE.

THERE MAY STILL BE POCKETS OF IFR FOG IN DEEPER VALLEYS OF THE SRN
WV COAL FIELDS.

EARLY MORNING LLJ AOA 3 KFT CLOSE TO 40 KTS MAY BRING WIND SHEAR
CLOSE TO LLWS CRITERIA BUT HEIGHT OF LLJ AND SOME WIND AT THE SFC
WILL LIKELY KEEP CRITERIA /20 KTS WITHIN A 200FT LAYER EXISTING
WITHIN 2 KFT OF THE SFC/ FROM BEING MET.

SFC FLOW WILL AVERAGE FROM THE S THROUGH THE PERIOD...A BIT GUSTY ON
THE RIDGES AND HILLTOPS OVERNIGHT AND FRI.  THE WIND WILL TEND TO
VEER TOWARD SW DURING THE DAY AND BACK TOWARD SE AT NT.  FLOW ALOFT
WILL REMAIN MODERATE SW.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: IF SHALLOW INVERSION SETS UP AND ALLOWS WINDS
AT GROUND TO DECREASE...THICKER FOG POSSIBLE AT CRW AND EKN.  LLWS
CRITERIA COULD THEN BE MET.  ALSO...TIMING THE FORMATION OVERNIGHT
AND EROSION SAT MORNING OF THE LOW STRATUS CIGS INTO THE SRN
MOUNTAINS AROUND BKW 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                              SAT 09/20/14
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  H    H    M    M    M    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  L    M    M    L    L    L    L    M    M    M    M    H
EKN CONSISTENCY  H    H    M    H    H    H    H    M    H    H    H    H
PKB CONSISTENCY  H    H    H    M    M    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 06Z SUNDAY...
BRIEF IFR CONDITIONS POSSIBLE SUNDAY IN SHOWERS/THUNDERSTORMS.

&&

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

&&

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





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.