699  
FXUS61 KRLX 301412  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
1012 AM EDT THU OCT 30 2014  
   
SYNOPSIS
 
 
HIGH PRESSURE TODAY. LOW PRESSURE WITH RAIN FRIDAY EVENING. COLDER  
AIR AND THE LOW SHOULD RESULT IN ACCUMULATING SNOW IN THE MOUNTAIN  
COUNTIES OVERNIGHT FRIDAY NIGHT INTO SATURDAY.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
15Z UPDATE...  
NO MAJOR CHANGES.  
 
PREVIOUS DISCUSSION...  
HIGH PRESSURE...CURRENTLY CENTERED OVER THE MIDDLE  
MISSISSIPPI VALLEY...WILL BUILD NORTHEAST INTO THE AREA BY LATE  
TODAY...AND THEN TO OUR EAST BY LATE TONIGHT. EXPECT AN AREA OF  
LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES REGION BY LATE  
TONIGHT...WITH A COLD FRONT EXTENDING SOUTHWEST ACROSS CENTRAL KY  
INTO SOUTH TEXAS.  
 
AS EXPECTED...CLOUDS WERE DEVELOPING...MAINLY ACROSS NORTHERN  
PORTIONS OF THE AREA. SOME CLOUDS SHOULD CONTINUE TODAY...WITH  
SOUTHERN PORTIONS OF THE REGION SEEING MORE SUNSHINE THAN THE  
NORTH.  
 
AS THE LOW AND ASSOCIATED COLD FRONT APPROACH FROM THE WEST...  
EXPECT CLOUDS WILL BEGIN TO THICKEN AND LOWER...WITH MOSTLY CLOUDY  
SKIES EXPECTED BY LATE TONIGHT. POPS SHOULD BEGIN TO INCREASE FROM  
THE WEST LATE AS WELL.  
 
FORECASTED HIGHS TODAY LOOKED GOOD AND HAVE ONLY MADE SOME TWEAKS  
TO REFLECT LATEST TRENDS IN GUIDANCE.  
 
FOR TONIGHT...LATEST GUIDANCE IS COOLER THAN THE PREVIOUSLY  
FORECASTED VALUES. WITH LIGHT WINDS AND DRY AIR...THIS TREND IS  
BELIEVABLE. HOWEVER...FEEL INCREASING CLOUDS SHOULD ACT TO LIMIT  
OF RADIATIONAL COOLING THAT MAY OCCUR. HAVE LOWERED OVERNIGHT  
LOWS...HOWEVER...NOT AS MUCH AS SUGGESTED BY THE LATEST GUIDANCE.  
 

 
   
SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/
 
 
FIRST MEANINGFUL SNOW OF THE SEASON ANTICIPATED FOR THE WV AND VA  
MOUNTAINOUS COUNTIES...AND PERHAPS HILLTOPS IN THE SOUTHERN WV COAL  
FIELDS...OVERNIGHT FRIDAY NIGHT AND SATURDAY MORNING...  
 
WHATEVER THE WINTER OF 2014/15 WILL BRING...IT BEGINS EARLY AND  
LOUDLY...AS MAJOR E COAST L/W TROUGH AMPLIFICATION TAKES PLACE EARLY  
THIS PERIOD.  
 
A NRN UPPER LEVEL LOW DROPS ALMOST DUE S...DOWN THE BACKSIDE OF THE  
AMPLIFYING L/W AND INTO THE BASE...OR FROM THE GREAT LAKES TO THE  
SMOKIES...12Z FRI-12Z SAT. A LEAD SRN STREAM S/W TROUGH ALREADY IN  
THE BASE OF THE L/W OVER THE SERN STATES AS OF 12Z FRI...MOVES UP  
THE E SIDE OF THE L/W...ALONG THE E COAST...GENERATING AN INITIAL  
SFC WAVE ALONG AN OFFSHORE BAROCLINIC ZONE.  
 
FRI FINDS THE FCST AREA ALREADY IN IN RELATIVELY DRY...CHILLY AIR  
NEARLY CAPABLE OF SUPPORTING SNOW WITH KEY VALUES NEAR  
THRESHOLDS...LIKE 0C AT H8.5 AND 540 KM BETWEEN H5 AND H10...ALONG  
WITH PROGGED PW VALUES OF ONLY TWO THIRDS OF AN INCH. AS SUCH...THE  
NRN STREAM UPPER LEVEL LOW WILL NOT HAVE MUCH MOISTURE OR  
BAROCLINICITY TO WORK WITH AS IT DIGS THROUGH OR JUST W OF THE FCST  
AREA...WITH ASSOCIATED FRONTOGENETIC FORCING NOT REALLY CRANKING UP  
UNTIL THE LOW APPROACHES THE SE COAST.  
 
SHOWERS WILL BREAK OUT FRI AS THE SFC COLD FRONT ASSOCIATED WITH THE  
NRN STREAM FEATURE...APPROACHES AND THEN MOVES THROUGH FROM THE W.  
PRECIPITATION WILL LIKELY BECOME MORE WIDESPREAD FRI NT INTO  
SAT...AS THE NEGATIVE TILT FEATURE DIGGING S OF THE AREA PLACES THE  
AREA IN STRONG FORCING INCLUDING Q VECTOR CONVERGENCE. THE  
AFOREMENTIONED FACTORS WILL KEEP QPF VALUES MAINLY BELOW A HALF AN  
INCH / 6 HRS.  
 
THE COLD CORE SLIDES SEWD ACROSS SW PORTIONS OF THE FCST AREA FRI NT  
INTO SAT...WHILE THE WARMER AIR GETS HUNG UP OVER NERN PORTIONS OF  
THE FCST AREA FRI INTO FRI NT...UNTIL THE PRIMARY SFC LOW JUST TO  
THE N FILLS BY SAT MORNING. THE WARM BOUNDARY LAYER AIR DOES NOT  
GET COMPLETELY ERADICATED...KEEPING ACCUMULATING SNOW LEVELS ABOVE  
2500 OR EVEN 3000 FT...WITH LEVELS PERHAPS GETTING BELOW 2500 FT  
OVER SW PORTIONS OF THE FCST AREA...CLOSER TO THE UPPER LOW TRACK.  
 
ALL OF THIS SORT OF BALANCES SNOW AMTS IN THE MOUNTAINS THE COLDEST  
AIR OVER THE SMALLER SRN MOUNTAINS. GENERALLY LOOKING AT COUNTY  
AVERAGES IN THE ADVISORY RANGE AT BEST...WITH PEAK AMOUNTS NEAR 4  
INCHES FOR THE SRN MOUNTAINS AND AS HIGH AS 6 INCHES AT SNOWSHOE.  
WILL THUS MAINTAIN HWO MENTION FOR THE MOUNTAINOUS COUNTIES.  
 
AS THE L/W SHIFTS E...THE SYSTEM SCOOTS UP THE E  
COAST...OFFSHORE...IT MAKE TAKE UNTIL SUN MORNING FOR THE UPSLOPE  
SNOWS SHOWERS TO WANE AND THE CLOUDS TO BREAK UP. HIGH PRESSURE  
SAILS ACROSS SUN NT...PROVING IDEAL RADIATIVE COOLING MOST OF THE NT,  
 
HAVE TEMPERATURES NEARER LOWER SIDE OF GUIDANCE WITH BIAS CORRECTED  
GUIDANCE NOT A GOOD FIT IN THIS HIGHLY ANOMALOUS PATTERN.  
 

 
   
LONG TERM /MONDAY THROUGH WEDNESDAY/
 
 
MODELS RAPIDLY LIFT THE UPPER LOW OFF THE ATLANTIC COAST SATURDAY  
NIGHT...WHICH WILL END THE LINGERING MOUNTAIN SNOW SHOWERS...WITH  
ONLY ADDITIONAL MINOR HIGH ELEVATION ACCUMULATIONS BEFORE DAWN  
SUNDAY. STRONG DRY CANADIAN HIGH PRESSURE WILL THEN BE THE DOMINANT  
FEATURE THROUGH MONDAY. THE HIGH PRESSURE CENTER WILL SETTLE OVER  
THE AREA SUNDAY NIGHT...THEN SHIFT OFF THE ATLANTIC COAST EARLY NEXT  
WEEK. THIS WILL BRING A DRAMATIC TURNAROUND IN TEMPERATURES THIS  
PERIOD. WELL BELOW NORMAL TEMPERATURES THIS WEEKEND WITH WIDESPREAD  
SUB FREEZING TEMPERATURES SUNDAY NIGHT UNDER THE CENTER OF HIGH  
PRESSURE...WILL WARM UP TO NEAR NORMAL VALUES BY TUESDAY AS THE HIGH  
SHIFTS OFF THE ATLANTIC COAST.  
 
WHILE ALL THIS ABOVE IS HAPPENING...MODELS SHOW ANOTHER UPPER TROUGH  
DIGGING INTO THE MISSISSIPPI VALLEY AND DRIVING IT EAST TO AFFECT  
OUR AREA LATER TUESDAY AND WEDNESDAY. BY THIS TIME...TEMPERATURES  
WILL BE WELL ABOVE FREEZING FOR A RAIN EVENT.  
 

 
   
AVIATION /14Z THURSDAY THROUGH MONDAY/
 
 
15Z UPDATE...  
NO MAJOR CHANGES. VFR CONDITIONS FOR MOST SITES EXPECTED TO  
CONTINUE THROUGH THE AFTERNOON.  
 
PREVIOUS DISCUSSION...  
LATEST SURFACE OBSERVATIONS AND FOG CHANNEL SATELLITE  
IMAGERY SHOWS CLOUDS AT OR ABOVE 3500 FT WHERE DEVELOPING ACROSS  
PORTIONS OF THE AREA. STILL NOT REAL CONFIDENT THAT MUCH IN THE  
WAY OF MIST/FOG WILL DEVELOP BETWEEN 07Z AND 12Z...ESPECIALLY WITH  
THE DEVELOPMENT OF THESE CLOUDS. HAVE CONTINUED MENTION OF MVFR  
CONDITIONS WHERE THE CLOUDS ARE MOST LIKELY TO IMPACT...SUCH AS  
CRW AND EKN...WITH IFR CONDITIONS POSSIBLE ACROSS THE VALLEYS OF  
THE SOUTHERN COAL FIELDS.  
 
EXPECT ANY IFR/MVFR CONDITIONS THAT MAY DEVELOP WILL IMPROVE BY  
14Z...WITH VFR CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE  
AREA.  
 
WINDS SHOULD BE LIGHT THROUGH THE PERIOD.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...  
 
FORECAST CONFIDENCE: MEDIUM.  
 
ALTERNATE SCENARIOS: TIMING AND DENSITY OF MORNING FOG.  
 
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 14 15 16 17 18 19 20 21 22 23 00 01  
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21  
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 12Z FRIDAY...  
IFR DEVELOPING FRIDAY EVENING IN RAIN...CHANGING TO MOSTLY SNOW OVER  
SOUTHERN MOUNTAIN COUNTIES INCLUDING BKW 06Z TO 12Z SATURDAY...WITH  
A RAIN AND SNOW MIXTURE IN THE LOWLANDS SATURDAY.  
 

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

 
 

 
SYNOPSIS...JSH/TRM  
NEAR TERM...JSH/LS  
SHORT TERM...TRM  
LONG TERM...JMV  
AVIATION...JSH/LS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab WV Page
The Nexlab OH Page
The Nexlab KY Page
The Nexlab VA Page Main Text Page