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Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 170234
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1034 PM EDT SUN JUN 16 2013

.SYNOPSIS...
-- Changed Discussion --ONE DISTURBANCE ALOFT EXITS EARLY OVERNIGHT. ANOTHER MOVES THROUGH
EARLY MONDAY MORNING. DEEPER MOISTURE IS THEN SHUNTED SOUTH MONDAY
AS THAT DISTURBANCE EXITS. ANOTHER DISTURBANCE PASSES TUESDAY.-- End Changed Discussion --

.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --1030 PM UPDATE...
FINE TUNED BACK EDGE OF POPS WITH S/W TROF CURRENTLY MOVING ON
THROUGH. HAVE CHANCE POPS RETURN S AS ANOTHER S/W TROF MAY GENERATE
SHOWERS LATE OVERNIGHT THERE. LOWERED OVERNIGHT TEMPERATURES IN
ACCORDANCE WITH EVENING TRENDS AND LAV.

800 PM UPDATE...
FCST ON TRACK.

PREV DISCN...
THE ONE MID LEVEL DISTURBANCE...DISCUSSED IN THE MORNING
UPDATE...WAS CROSSING THE MOUNTAIN COUNTIES AT 18Z. NEW CELLS
WERE FORMING ALONG ITS TRAIL ACROSS SOUTHERN WV AT 18Z.

AS IS QUITE OFTEN IN SUMMER...NEAR TERM MODELS/GUIDANCE STRUGGLING
WITH ADDITIONAL DISTURBANCES MOVING UP THE OHIO VALLEY FROM SOUTHERN
INDIANA. THINKING BEST SUPPORT ARRIVES 21Z TO 02Z ACROSS THE
SOUTHERN HALF OF OUR CWA.

STILL HAVE THAT WATER CONCERN FOR THE POSSIBILITY OF WEST TO EAST
TRAINING DEVELOP IN THIS EVENING PATTERN. STEERING MID LEVEL FLOW
DOES WEAKEN FROM AROUND 40 KNOTS TO 25 TO 30 KNOTS. SO CELL MOTION
MAY DECREASE BY THIS EVENING. PRECIPITABLE WATER AROUND 1.7 INCHES
AT 18Z...MAY PEAK AROUND 00Z AT 1.8/1.9 SOUTH OF THE ROUTE 50
CORRIDOR. SO CONTINUED A WATER HAZARD IN THE HWO MAINLY FOR SOUTHERN
HALF OF OUR CWA TONIGHT. STILL THINKING THIS THREAT WOULD SETTLE
SOUTH WITH TIME. THINK THE BEST PLAN OF ACTION IS TO...CONTINUING
TO TAKE A MONITORING MESOSCALE MODE...TO SEE HOW THIS ALL EXACTLY
SETS UP AND UNFOLDS. STILL WOULD TAKE 1.5 TO 2 INCHES OF RAIN IN
SHORT TIME FRAME BEFORE REAL CONCERNS ABOUT SMALL STREAM FLOODING.
AFTER COORDINATION...BEST MOVE IS NOT TO POST ANY HEADLINES AT 18Z.

THINKING THE FRONTAL BOUNDARY WILL ONLY TRY TO SNEAK DOWN AS FAR
SOUTH AS UNI-PKB-CKB BY 12Z MONDAY...THEN STALL AND WEAKEN. SO DO
NOT HAVE FRONT REACHING SOUTHERN COUNTIES. AS A RESULT...
WILL BE SLOW TO COMPLETELY REMOVE SHOWER CHANGES IN THE NORTH LATE
TONIGHT WITH BOUNDARY IN VCNTY...DESPITE DEEPER MOISTURE WELL TO THE
SOUTH.

12Z MODELS PUSH THE DEEPER MOISTURE EVEN TO THE SOUTH AND SOUTHWEST
OF OUR SOUTHERN COUNTIES MONDAY. YET...WITH LOW LEVEL MOISTURE
LINGERING. FIGURING ON PLENTY OF LOWER CLOUDS AT DAWN..THE LIFTING
BY AFTERNOON. YET...STILL HELD ONTO SOME 20/30 POPS IN SOUTHERN HALF
OF THE CWA EVEN MONDAY AFTERNOON.

AT 18Z...STILL WORKING ON MIN AND MAX TEMPERATURES FOR TONIGHT...BUT
NOT PICTURING BIG CHANGES.-- End Changed Discussion --

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
SOME RUN TO RUN DIFFERENCES IN MODELS WITH HOW THE SYNOPTIC PATTERN
PROGRESSES TUESDAY. PREVIOUS RUNS OF THE NAM/GFS WERE SHOWING A COLD
FRONT PUSHING THROUGH DURING THE DAY...BUT NEWER RUNS OF
NAM/GFS...AND ALSO THE 00Z ECMWF...LOOK TO KEEP THE BULK OF THE
ENERGY SOUTH...WITH JUST A WEAKER SECONDARY FRONT DROPPING THROUGH
CWA TUESDAY AFTERNOON. THE MOST ENERGETIC VORT MAX ALSO LOOKS
FARTHER SOUTH...PASSING ACROSS WV COAL FIELDS. SO DEVELOP AND AREA
OF LIKELY POPS ACROSS THE SOUTH EARLY TUESDAY...THEN EXPAND IT UP
THE MOUNTAINS BY MID DAY BEFORE EVERYTHING BEGINS SHIFTING SOUTH AND
EAST AS UPPER RIDGE BUILDS TO THE WEST.

ALL MODELS POINT TO A VORT MAX SLIDING THROUGH WEDNESDAY AS WELL.
NAM/ECMWF TAKE IT ACROSS THE NORTHERN CWA...WHILE GFS IS FARTHER
SOUTH. MOISTURE SHOULD BE DECREASING AS THE SURFACE FRONT CONTINUES
SOUTHEAST...SO KEPT CHANCE POPS IN THE MOUNTAINS WITH SLIGHT CHANCE
INTO THE EASTERN LOWLANDS...DRYING OUT AGAIN WEDNESDAY NIGHT.

TEMPERATURES WILL REMAIN SEASONABLE...WITH ONLY MINOR CHANGES MADE
TO PREVIOUS FORECAST.

.LONG TERM /THURSDAY THROUGH SUNDAY/...
UPPER RIDGE OVER THE SOUTHERN PLAINS WILL INFLUENCE MOST OF THE LONG
TERM PERIOD...WITH GRADUALLY WARMING AND MOISTENING OF THE BOUNDARY
LAYER. UNFORTUNATELY...THE RIDGE LOOKS RATHER DIRTY WITH SEVERAL
VORT MAXES DROPPING DOWN THE EASTERN SIDE IN THE NW FLOW OVER THE
MID AND UPPER OHIO VALLEY/CENTRAL APPALACHIANS. THIS SPELLS AT LEAST
SOME CHANCES OF THUNDERSHOWERS FOR THE SECOND HALF OF THE WORK WEEK.
UNTIL TIMING ON INDIVIDUAL VORTS CLEARS UP...KEPT PRECIP TIED TO THE
DIURNAL CYCLE...WITH THE HIGHEST POPS IN THE AFTERNOON OVER THE
HIGHER TERRAIN. BY NEXT WEEKEND...BOTH GFS AND ECMWF ADVERTISE A
STRONGER VORT MAX FOR SATURDAY...AND WITH MORE MOISTURE IN PLACE
INCLUDED CHANCE POPS CWA-WIDE.

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
TAF/S ISSUED WITH AMD NOT SKED ON ACCOUNT OF A COMMS ISSUE
PREVENTING SURFACE OBSERVATIONS FROM GETTING INTO THE SYSTEM. WITH
THE PROBLEM APPARENTLY RESOLVED...THE AMEND NOT SKED WILL BE REMOVED
UPON RECEIPT OF TWO CONSECUTIVE OBSERVATIONS.

A ZONES OF SHOWERS AND SCATTERED THUNDERSTORMS OVER MUCH OF THE AREA
WILL DRIFT SLOWLY S THROUGH THE PERIOD...AS A WEAK SURFACE FRONT
SLOWLY SLIPS S INTO THE AREA. ANY THUNDERSTORMS CAN QUICKLY BRIG
ABOUT IFR CONDITIONS ALONG WITH STRONG WIND GUSTS ESPECIALLY THIS
EVENING. OTHERWISE WE EXPECT MVFR STRATOCU AND FOG TO FORM
OVERNIGHT. LOCALLY DENSE FOG MAY FORM IN THE VALLEYS...ESPECIALLY
IN LOCATIONS THAT GOT RAIN DURING THE DAY OR WILL GET RAIN TONIGHT.

ONCE THE FOG BURNS OFF MON MORNING...WE EXPECT A MAINLY VFR
DAY...WITH SHOWERS AND THUNDERSTORMS SCATTERED ABOUT FROM AN HTS-CRW
LINE S.

SFC FLOW WILL REMAIN LIGHT SW OR VARIABLE...WHILE MODERATE W FLOW
ALOFT OVERNIGHT BECOMES LIGHT TO MODERATE ON MON.

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

FORECAST CONFIDENCE...MEDIUM TO HIGH.

ALTERNATE SCENARIOS: TIMING AND DURATION OF CONVECTION AND
ACCOMPANYING SUB-VFR CONDITIONS MAY VARY FROM CURRENT FCST. EXTENT
AND HEIGHT OF LOWER CIGS OVERNIGHT INTO MON ALSO MAY VARY. EXTENT
OF FOG FORMING OVERNIGHT MAY VARY FROM CURRENT FCST INTO MON MORNING.

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 MON 06/17/13
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY M M M H H H H H H H H H
HTS CONSISTENCY M M H H H H H H H H H H
BKW CONSISTENCY L M M M M M M M M H H H
EKN CONSISTENCY M H H H H M H H H H H H
PKB CONSISTENCY M M H M M M M H H H H H
CKB CONSISTENCY M M M M M M H H H M M H

AFTER 00Z TUESDAY...
IFR AT TIMES IN SHOWERS AND THUNDERSTORMS TUESDAY.

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

$$
SYNOPSIS...TRM/MZ
NEAR TERM...KTB/TRM
SHORT TERM...MZ
LONG TERM...MZ
AVIATION...TRM

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