Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 201919
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
319 PM EDT SUN APR 20 2014

.SYNOPSIS...
DRY ATMOSPHERE WITH COOL NIGHTS AND WARM DAYS HOLDS ON THROUGH MONDAY.
COLD FRONT WITH MORE AVAILABLE MOISTURE CROSSES TUESDAY. ANOTHER
COLD FRONT FRIDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
NO MAJOR CHANGES WERE NEEDED IN THE NEAR TERM PERIOD FROM PREVIOUS
FORECAST. DRY ATMOSPHERE IN PLACE...PARTICULARLY IN LOWER
LEVELS...AND DAYTIME HEATING/MIXING...HAS RESULTED IN RATHER LOW
RELATIVE HUMIDITIES THIS AFTERNOON...AS EXPECTED. RELATIVE
HUMIDITIES ACROSS MUCH OF THE AREA HAVE ALREADY DIPPED INTO THE
TEENS AS OF 17Z. FORTUNATELY...WINDS REMAIN RATHER LIGHT THUS
MITIGATING A MAJOR FIRE ISSUE...BUT HAVE A SPS IN EFFECT UNTIL 00Z
TO ACCOUNT FOR THE DRY FUELS/ATMOSPHERE.

WITH THE VERY DRY ATMOSPHERE IN PLACE...EXPECTING PERIOD OF COOL
NIGHTS...AND WARM SUNNY DAYS TO CONTINUE IN THE NEAR TERM PERIOD.
CLOUDS AND DEW POINTS WILL GRADUALLY INCREASE TOMORROW OUT AHEAD
OF NEXT APPROACHING SYSTEM...TO AFFECT AREA MONDAY NIGHT AND
TUESDAY. DID ELECT TO ADD A SLIGHT CHANCE FOR SHOWERS ACROSS FAR
WESTERN ZONES...MAINLY EASTERN KY...MONDAY EVENING. ELECTED TO
LEAVE THUNDER OUT OF FORECAST FOR NOW DUE TO TIMING OF POPS.

LAST CHECK OF RAWS OBSERVATIONS IN SOUTHWEST VA SHOW FUEL
MOISTURES SLIGHTLY HIGHER THAN REST OF CWA...SO FOR NOW...WILL
CONTINUE TO KEEP THEM OUT OF THE SPS.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
FRONT CROSSES TUESDAY WITH BAND OF LIKELY POPS WITH MONDAY STAYING
DRY. APPEARS SOME PREFRONTAL ACTION TUESDAY MORNING WITH BAND OF
SHRA AND THUNDER WITH FRONT TO FOLLOW. FOR TEMPS MONDAY...LEANED
HEAVILY ON WARMER GUIDANCE WITH UPPER 70S TO AROUND 80F DEPICTED
IN THE LOWLANDS. CONTINUED THAT TREND FOR LOWS MONDAY NIGHT GIVEN
INCREASE IN BL STIR AS WELL AS CLOUDS. SOME POST FRONTAL STRATUS
WILL GRADUALLY BREAK UP OVER THE LOWLANDS AND MOUNTAINS TUESDAY
NIGHT WITH A CHILLY NIGHT ON TAP. SOME PATCHY FROST FOR SHELTERED
LOCATIONS IS POSSIBLE ACROSS THE LOWLANDS. COOL DAY TO FOLLOW FOR
WEDNESDAY WITH SOME AFTERNOON STRATOCU ESPECIALLY N WV...WHICH
DISSIPATES LATE WITH PASSAGE OF THERMAL TROF AND SUBSEQUENT WAA.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BEHIND MID WEEK COLD FRONT BRINGS DRIER AND
PLEASANT TEMPERATURES FOR WEDNESDAY AND WEDNESDAY NIGHT...WITH A
QUICK WARM UP THURSDAY AND FRIDAY AHEAD OF AN APPROACHING NEW COLD
FRONT.

MODELS...ECMWF/GFS HAVE MAINTAIN CONSISTENCY DURING THE PAST FEW
DAYS...SLOWING DOWN THE COLD FRONT EARLY FRIDAY MORNING...WITH PCPN
CONTINUING THROUGH FRIDAY AS IT EXITS NORTHEAST. THIS TIMING IS NOT
DURING THE PEAK DIURNAL HEATING UNDER CUTTING THUNDERSTORM
PROBABILITY.  MODELS DO SHOW HIGH DEEP LAYERED SHEAR AS WITH MOST
COLD FRONTS. BUT TOO FAR OUT TO TRUST THERMODYNAMIC PARAMETERS. KEPT
INCREASE IN DEWPOINT AHEAD AND ALONG THE COLD FRONT.

USED HPC GUIDANCE FOR TEMPERATURES AS NOTICED ONLY MINOR CHANGES
FROM PREVIOUS DAYS. KEPT POPS TO 51 PERCENT TO ACCOUNT FOR QPF ON
GRIDS. POPS COULD BE INCREASE TO LIKELY OR CATEGORICAL WITH FRIDAYS
COLD FRONT AS TIME APPROACHES.

SHOWER ACTIVITY LINGERS FRIDAY NIGHT FOR SLIGHT CHANCE POPS.

HIGH PRESSURE BUILDS BEHIND THE FRONT FOR THE WEEKEND PROVIDING
FRESH AIR FROM THE NORTH.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WITH LIGHT SURFACE WINDS WILL PREVAIL THROUGH THE
PERIOD.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...

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.

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    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 18Z MONDAY...
NO IFR CONDITIONS EXPECTED.

&&

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

&&

$$
SYNOPSIS...ARJ/TRM/SL
NEAR TERM...SL
SHORT TERM...30
LONG TERM...ARJ
AVIATION...SL








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