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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 230836
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
435 AM EDT THU MAY 23 2013

.SYNOPSIS...
-- Changed Discussion --
WEAK COLD FRONT EXITS FIRST THING THIS MORNING.  SECOND COLD FRONT
CROSSES THIS EVENING.  UPPER DISTURBANCE CROSSES EARLY FRIDAY
MORNING.  COOL CANADIAN HIGH PRESSURE ARRIVES TO START THE WEEKEND.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
A COLD FRONT WAS BARELY DISCERNIBLE AT THE SURFACE AS IT MOVED
ACROSS THE FCST AREA OVERNIGHT...STRETCHING FROM EASTERN OHIO
SOUTHWARD ACROSS CENTRAL WV EARLY THIS MORNING.  NONETHELESS...SFC
AND DEEP LAYER MOISTURE DECREASE A BIT FROM WED...SO ATMOSPHERE WILL
NOT BE QUITE AS UNSTABLE AS ON WED.  EVEN SO...WITH 35 KTS LOW-MID
LEVEL FLOW AND WBZ SLOWLY FALLING THROUGH 9KFT COULD STILL LEAD TO
GUSTY WINDS AND SMALL HAIL FROM THUNDERSTORMS THIS AFTERNOON INTO
THIS EVENING.

IT IS A SFC COLD FRONT DRIVEN BY A PAIR OF UPPER LEVEL DISTURBANCES
CROSSING THE AREA THIS AFTERNOON AND EVENING THAT WILL PROVIDE THE
FORCING MECHANISM FOR THE PRECIPITATION.  THE FIRST S/W TROF
ACTIVATES CONVECTION IN THE WESTERN PORTION OF THE FCST AREA BY
EARLY AFTERNOON...AND MOVES ON E ACROSS THE AREA DURING THE
AFTERNOON.  THERE WILL BE A LITTLE FURTHER DRYING TAKING PLACE ONCE
THAT S/W CROSSES.

SECOND S/W TROF FOLLOWS BEHIND SFC COLD FRONT TONIGHT...WITH A
SECOND ROUND OF CONVECTION LIKELY ALONG/AHEAD OF THE FRONT THIS
EVENING.  THE POTENTIAL FOR CONVECTION WILL END WITH THE PASSAGE OF
THE COLD FRONT...BUT ANAFRONT SHOWERS ARE LIKELY TO PERSIST BEHIND
THE FRONT OVERNIGHT...ESPECIALLY IN THE MOUNTAINS AS DAWN APPROACHES
FRI.

RAISED TEMPERATURES A BIT TODAY TO REFLECT THE LATEST GUIDANCE.
LITTLE CHANGE NEEDED ON LOWS TONIGHT BUT FINESSED HOURLY
TEMPERATURES TO REFLECT PASSAGE OF THE COLD FRONT.  HAVE SNOWSHOE
DROPPING TO THE MID 30S BY DAWN SAT HAS H85 TEMPERATURES DROP TOWARD
0C.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
DRIER...COOLER WEATHER TO SET UP ACROSS THE REGION BEHIND THE
EXITING UPPER TROUGH. 850MB TEMPS WILL DROP INTO THE SINGLE DIGITS
FRIDAY NIGHT...SOME OF THE COOLEST AIR WE HAVE SEEN IN A FEW WEEKS.
THIS...ALONG WITH HIGH PRESSURE SETTLING INTO THE REGION...AND A
CLEARING SKY...WILL SEE GOOD RADIATIONAL COOLING FRIDAY NIGHT...AND
FROST/FREEZE HEADLINES MAY BE NEEDED IN MANY
LOCATIONS...PARTICULARLY ACROSS THE NORTH. IN MOUNTAINOUS
COUNTIES...THIS WOULD MAINLY AFFECT SHELTERED VALLEYS...AS NOCTURNAL
LLJ SHOULD PREVENT FROST FORMATION. WILL HIGHLIGHT THE POTENTIAL FOR
FROST/FREEZE IN THE HWO. FLY IN THE OINTMENT HOWEVER WILL BE THE
POTENTIAL FOR MID AND HIGH CLOUDS MOVING INTO THE AREA FROM AN UPPER
DISTURBANCE. THIS MAY PREVENT FROST FORMATION PARTICULARLY ACROSS
EASTERN KY...SOUTHWEST VA...AND SOUTHERN COAL FIELDS OF WV.

COULD SEE A SLIGHT CHANCE FOR SHOWERS SUNDAY MORNING ACROSS SOUTHERN
ZONES...BUT FOR NOW...MUCH OF THE ENERGY AND MOISTURE ASSOCIATED
WITH THIS LOOKS TO REMAIN OFF TO OUR WEST...SO FOR NOW WILL MAINTAIN
A DRY FORECAST SUNDAY MORNING.
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
HAVE GENERALLY FOLLOWED WPC THINKING FOR THIS PORTION OF THE
FORECAST.

HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER ACROSS THE AREA INTO
SUNDAY NIGHT.  HOWEVER...MODELS SUGGEST A FEW WEAK MID-LEVEL
SHORTWAVE MAY MOVE SOUTHEAST.  BELIEVE AREA SHOULD REMAIN DRY...WITH
A FEW MORE CLOUDS BEGINNING SATURDAY NIGHT

A WARM FRONT WILL THEN DEVELOP AND APPROACH THE REGION ON MONDAY. AS
A RESULT...THERE WILL BE A CHANCE OF SHOWERS AND STORMS MONDAY AND
TUESDAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.

TEMPERATURES ON SATURDAY SHOULD BE NEAR NORMAL WITH DAYTIME HIGHS IN
THE 70S ACROSS THE LOWLANDS...WITH 60S ACROSS THE HIGHER
ELEVATIONS.  AS THE HIGH PUSHES EAST ON SUNDAY...EXPECT TEMPERATURES
TO WARM TO SLIGHTLY ABOVE NORMAL VALUES MONDAY AND TUESDAY.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
VFR TO OCCASIONAL MVFR CIGS/MIST IN SHOWERS OVERNIGHT IMPROVING TO
VFR DURING THE DAYLIGHT MORNING HOURS THU.

ANOTHER FRONT APPROACHING FROM THE W THU AFTERNOON WILL GIVE RISE TO
CONVECTION AGAIN THU8 AFTERNOON AND EVENING...BRINGING MVFR AND
LOCALIZED IFR CONDITIONS.  THUNDERSTORMS CAN PRODUCE GUSTY WINDS THU
AFTERNOON AND EVENING.

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

FORECAST CONFIDENCE...MEDIUM.

ALTERNATE SCENARIOS: TIMING AND DEGREE OF FLIGHT RESTRICTIONS DUE TO
SHOWERS AND POST RAIN FOG COULD VARY...WITH ISOLATED DENSE FOG NOT
OUT OF THE QUESTION.  TIMING OF CONVECTION THU AFTERNOON AND NT
COULD ALSO 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                              THU 05/23/13
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  M    M    M    M    M    M    M    H    H    H    H    H
HTS CONSISTENCY  H    H    M    M    M    H    H    H    H    H    H    H
BKW CONSISTENCY  M    M    M    M    M    M    H    M    M    M    M    H
EKN CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    M    M    H    H    H    H    H    H    H    H
CKB CONSISTENCY  M    M    M    M    M    H    H    M    M    H    H    H

AFTER 06Z FRIDAY...
IFR CONDITIONS POSSIBLE IN FOG EARLY SATURDAY MORNING.

&&

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

&&

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