924
FXUS61 KRLX 161754
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
154 PM EDT WED OCT 16 2013
.SYNOPSIS...
MOIST AIR TODAY AHEAD OF FRONT. COLD FRONT INTO THE WESTERN LOWLANDS
THIS EVENING. FRONT SLOWS DOWN OVERNIGHT. WAVE PASSES ALONG FRONT ON
THURSDAY. DRIER AND COOLER AIR FOR FRIDAY AND FRIDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
130 PM UPDATE...
PRECIP STILL SLOWLY PUSHING EASTWARD ACROSS THE OHIO RIVER BUT IS
PICKING UP SOME FORWARD SPEED. LOWERED MAX TEMPS THIS AFTERNOON
2-3 DEGREES MOST LOCATIONS PER TRENDS AND NEAR-TERM GUIDE.
PREVIOUS DISCUSSION...
IT IS NEVER EASY...BUT AT LEAST WE ARE ENJOYING ANOTHER PREDAWN
WITH TEMPERATURES IN THE 50S AND LOWER 60S IN THE WEST. SOME 40S
THOUGH IN THE DEEPER MOUNTAIN VALLEYS OF RANDOLPH AND POCAHONTAS
COUNTIES THOUGH.
AT 07Z HAVE FRONT APPROACHING A FWA...IND...EVV...PAH LINE. HAVE
FRONT REACHING NEAR CMH 17Z OR SO...THEN SLOWING DOWN BY
DARK/23Z...NEAR A A PIT...UNI...IOB LINE.
THE FRONT HAS ONE THING GOING FOR IT...AVAILABLE MOISTURE.
PRECIPITABLE WATER ALREADY AROUND 1.5 ALONG THE OHIO RIVER COUNTIES
THIS PREDAWN. SURFACE DEW POINTS NEAR 60 DEGREES. ONE 500 MB VORT
MAX MOVES NE...UP THE OHIO RIVER REACHING INTO SW PENNSYLVANIA
AROUND13/14Z. IT IS WAKE...HAVING A TOUGH TIME FINDING MUCH SUPPORT
FOR LATER TODAY. AS A RESULT...WILL BE SLOWER INCREASING THE POPS
OVER THE MOUNTAINOUS COUNTIES. ALSO...CONFIDENCE IN LIKELY POP INTO
THE HEART OF WV HAS LOWERED. WILL KEEP LIKELY POPS MOSTLY W OF THE
I-79 CORRIDOR TODAY. OF COURSE...THE CONFIDENCE IN THE MAXIMUM
TEMPERATURE HAS LOWERED TOO. DID TRY TO INCREASE MAX TEMPERATURE A
BIT FOR CKB TO EKN VCNTY WITH THOSE LOWER POPS.
AS THE FRONT CREEPS A BIT FURTHER SE TONIGHT...CEILINGS SHOULD
LOWER...COULD EVEN SEE THE PCPN TAKE MORE OF A DRIZZLE FORM FOR THE
COUNTIES JUST IN THE WAKE OF THE FRONT. BUT AS OF NOW WILL LEAVE IT
AS SHOWERS. BASED ON MODEL FORECAST SOUNDINGS AND LACK OF AFTERNOON
SUPPORT...DID LOWER THE CHANCE OF T TO AOB 14 PCT.
HAVE THE FRONT ENDING UP CKB TO HTS AROUND 06Z THURSDAY..THEN MAYBE
INCH A BIT FURTHER S BEFORE 12Z THURSDAY. AS A RESULT...A STRONG
MOISTURE AND TEMPERATURE SETS UP ACROSS OUR CWA...WHICH AS
USUAL...MAKES HOURLY DETERMINISTIC FORECASTS/GRIDS DIFFICULT.
HAVE THE HOURLY POPS STOPPING ITS DECLINE BY 09Z THURSDAY. WITH DRY
NORTH OF A HTS-CRW-SUTTON LINE. YET...BETWEEN 09Z AND 12Z...START
INCREASING POPS FROM THE S AND SW WITH WAVE ALONG THE FRONT.
IN THIS PATTERN...TRIED TO HOLD MINIMUM TEMPERATURES HIGHER THAN WE
HAD FOR THE CRW AND SOUTHERN WV COAL FIELDS OVERNIGHT TONIGHT.
YET...STILL SOME MID 40S IN PERRY COUNTY WITH THAT CLEARING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
FRONT SHOULD BE NEARLY STALLED ACROSS CENTRAL CWA TO START THE SHORT
TERM PERIOD...WITH WAVE ALONG THE FRONT RIDING NE OUT OF TN/KY.
CLOSED 500MB LOW WILL BE PASSING OVER E IA/NW IL...AND OPENING UP IN
RESPONSE TO STRONGER UPPER LOW DROPPING THROUGH CENTRAL CANADA. IN
COORDINATION WITH NEAR TERM...SPED UP AND INCREASED POPS FOR THE
SURFACE WAVE. WAVE SHOULD CROSS WV FROM SW TO NE THROUGH THE
DAY...AND AS IT PASSES IT WILL GET COLD FRONT MOVING AGAIN.
FLATTENING 500MB TROUGH PASSES SATURDAY IN FAIRLY QUICK FLOW...AND
MAINTAINED CHANCE SHOWERS ACROSS THE NORTH.
WITH SLIGHTLY WARMER TEMPS FORECASTED THURSDAY NIGHT...COMBINED WITH
SOME LINGERING CLOUDS AND SURFACE FLOW BEHIND THE COLD FRONT...WILL
REMOVE HWO MENTION OF FROST FOR SE OHIO. STILL COULD GET ISOLATED
UPPER 30S THERE THOUGH. 850S ALREADY WARMING BACK UP LATER FRIDAY
INTO FRIDAY NIGHT...SO BUMPED UP OVERNIGHT LOWS THEN TOO. MINIMAL
CHANGES TO HIGHS BY BLENDING IN BIAS-CORRECTED SREF
GUIDANCE...GENERALLY HAVE 60S AREA WIDE EACH AFTERNOON.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THIS PERIOD WILL BE DOMINATED BY A POLAR VORTEX OVER EASTERN CANADA
WITH GENERALLY DRY WEST TO NORTHWEST FLOW ALOFT OVER THE EASTERN
HALF OF THE NATION. THIS WILL KEEP TEMPERATURES SLIGHTLY BELOW
NORMAL. LITTLE PRECIPITATION IS EXPECTED AS THE GULF MOISTURE WILL
BE SUPPRESSED. THERE IS GOOD MODEL AGREEMENT ON THIS SCENARIO.
OTHERWISE...HIGH PRESSURE WILL DOMINATE WITH DRY CONDITIONS AND
SLIGHTLY BELOW NORMAL TEMPERATURES INTO EARLY NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
18Z WEDNESDAY THROUGH 18Z THURSDAY...
ACTIVE WEATHER WITH SUB-VFR CONDITIONS PREVALENT IN THE VALID
PERIOD WITH A COLD FRONT AND UPPER TROUGH MOVING ACROSS THE
FORECAST AREA. ONE LINE OF SHOWERS CURRENTLY CROSSING THE OIO
RIVER EXPECTED TO CONTINUE EASTWARD ACROSS THE AREA THIS
AFTERNOON. WITH IT MVFR VIS AND CIGS...WITH INTERMITTENT IFR
VIS...WILL BE POSSIBLE.
THERE SHOULD BE A BRIEF RELATIVE LULL IN PREPIP COVERAGE THIS
EVENING...WITH SHOWERS QUICKLY RETURNING FROM SOUTHWEST TO
NORTHEAST AFTER 06Z THU AS A DISTURBANCE PUSHES NORTHEAST...WITH A
GOOD CHANCE OF PRECIP FOR MANY LOCATIONS EAST OF THE OHIO RIVER BY
AROUND THE 12Z TIME FRAME. THIS ALONG WITH COOLER NIGHT TEMPS SHOULD
RESULT IN WIDESPREAD IFR AND POSSIBLE LIFR CIGS FROM ROUGHLY THE
OHIO RIVER EASTWARD WITH LITTLE IMPROVEMENT FOR THE REMAINDER OF
THE VALID PERIOD. SOME SLIGHTLY BETTER CIGS IN THE MVFR RANGE MAY
BE REALIZED AT THE SITES ON THE OHIO RIVER.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATIVE SCENARIOS: CIGS AND VIS MAY VARY WITH PRECIP COVERAGE.
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 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY M M M M M M M M M M M H
HTS CONSISTENCY M M M M M M M M M M M M
BKW CONSISTENCY M M H H H H M M M M M M
EKN CONSISTENCY M H H H H M M M M M M H
PKB CONSISTENCY H H H H H M M M M M H H
CKB CONSISTENCY H H M M M M M M M M H H
AFTER 18Z THURSDAY...
ALONG FRONTAL WAVE...IFR LIKELY IN RAIN/FOG AND STRATUS THURSDAY
AFTERNOON AND INTO THE EVENING HOURS EAST. IMPROVING THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB/50
SHORT TERM...MZ
LONG TERM...JMV
AVIATION...50