535  
FXUS61 KRLX 260010  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
710 PM EST SUN JAN 25 2015  
   
SYNOPSIS
 
 
LOW PRESSURE SYSTEM MOVES ACROSS THE AREA TONIGHT AND MONDAY.  
NORTHWEST FLOW TUESDAY BEHIND MAJOR COASTAL STORM WELL TO THE  
NORTHEAST. HIGH PRESSURE WEDNESDAY. LOW PRESSURE LATE THURSDAY.  
 

 
   
NEAR TERM /THROUGH MONDAY/
 
 
CURRENT FORECAST REMAINS ON TRACK. NO CHANGES NECESSARY AT THIS  
TIME.  
 
PREVIOUS DISCUSSION BELOW...  
QUITE A COMPLICATED FORECAST IN THE NEAR TERM PERIOD. FRONTAL  
BOUNDARY ACROSS CENTRAL OHIO AT 18Z...WITH LIGHT PRECIPITATION  
FORMING ALONG IT. MIXTURE OF PRECIPITATION JUST TO OUR  
NORTH...WITH AREAS OF EITHER RAIN...OR A RAIN SNOW MIX...WITH SNOW  
FARTHER TO THE NORTH ACROSS NORTHERN OHIO.  
 
THE SURFACE LOW...CURRENTLY CENTERED ON CENTRAL KY...WILL MOVE EAST  
ACROSS THE AREA TONIGHT...WITH PRECIPITATION CHANCES INCREASING AS  
IT DOES SO. EXPECT BULK OF PRECIPITATION TO START OUT AS  
RAIN...WITH A GRADUAL TRANSITION TO A RAIN SNOW MIX...THEN ALL  
SNOW THROUGHOUT THE NIGHT AND INTO THE DAY MONDAY AS THE LOW  
PUSHES EAST...AND UPPER TROUGH DIGS SOUTH ACROSS THE AREA...WITH  
FALLING TEMPERATURES EXPECTED DURING THE DAY ON MONDAY. THERE  
COULD BE A VERY BRIEF PERIOD OF SLEET DURING THE TRANSITION  
PERIOD.  
 
AT THIS POINT...FEEL CURRENT ADVISORY FOR JUST PERRY COUNTY SEEMS  
REASONABLE. BASED ON FORECAST SOUNDINGS...WHICH WILL BE FAVORABLE  
FOR SNOW...SURFACE TEMPERATURES FOR MUCH OF THE PERIOD WILL HOVER  
AROUND OR ABOVE THE FREEZING MARK...THUS LIMITING THE SNOWFALL  
POTENTIAL. SO ALTHOUGH IT MAY BE SNOWING...WE MAY HAVE A HARD TIME  
ACCUMULATING ADVISORY CRITERIA SNOW. OUTSIDE OF PERRY  
COUNTY...WHERE 1 TO 3 INCHES ARE CONFIGURED...GENERALLY HAVE AROUND  
AN INCH ACROSS SURROUNDING SOUTHEAST OHIO COUNTIES...WITH 1 TO 4  
ACROSS THE MOUNTAINS OF WEST VIRGINIA. PERRY COUNTY APPEARS TO STILL  
BE THE MOST FAVORABLE LOWLAND COUNTY FOR ACCUMS AS SURFACE  
TEMPERATURES SHOULD DROP EARLIER...AND STAY COLDER THERE LONGER.  
 

 
   
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/
 
 
PRECIPITATION CHANCES WILL DECREASE FROM THE NORTHWEST MONDAY NIGHT  
AS THE SYSTEM CONTINUES TO PULL AWAY FROM THE AREA. HOWEVER...  
NORTHWEST UPSLOPE FLOW...COLD AIR AND SUFFICIENT LOW-LEVEL MOISTURE  
SHOULD CONTINUE A CHANCE OF SNOW...MAINLY IN THE MOUNTAINS...INTO  
EARLY WEDNESDAY.  
 
APPEARS THE BEST CHANCES FOR SNOW ACCUMULATIONS IN THE MOUNTAINS  
WILL BE ON TUESDAY WHEN DEEP NORTHWEST FLOW BECOMES BETTER  
ESTABLISHED WHILE THE LOW-LEVEL MOISTURE IS STILL DEEP ENOUGH.  
 
CURRENT THINKING IS THAT SEVERAL ADDITIONAL INCHES OF SNOW WILL BE  
POSSIBLE ACROSS THE HIGHER ELEVATIONS...MAINLY MONDAY NIGHT AND  
TUESDAY.  
 
HIGH PRESSURE BUILDS IN WEDNESDAY...BRINGING THE SNOW CHANCES TO  
AN END.  
 
GUIDANCE TEMPS WERE COLDER FOR LOWS AND HIGHS THAN PREVIOUS  
FORECAST. WITH THIS IN MIND...HAVE TWEAKED THESE VALUES DOWN TO  
REFLECT LATEST THINKING.  
 

 
   
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
 
 
PERIOD STARTS WITH HIGH PRESSURE OVERHEAD...THAT ALMOST IMMEDIATELY  
GIVES WAY TO A LOW PRESSURE SYSTEM APPROACHING FROM THE W. MODELS  
ARE GENERALLY A BIT FASTER WITH THIS SYSTEM...SO PRECIPITATION COULD  
REACH WRN PORTIONS OF THE FCST AREA AROUND DAWN THU. THIS THEN  
SPREADS E ACROSS THE AREA THU...FOLLOWED BY UPSLOPE PRECIPITATION IN  
THE WAKE OF THE SYSTEM THU NT INTO FRI.  
 
WITH THE LOW CENTER TRACKING OF THE AREA...ENOUGH WARM AIR SHOULD  
ARRIVE FOR A MAINLY WET...NOT WHITE OR ICY...THU. HOWEVER...MIXED  
PRECIPITATION INCLUDING FREEZING RAIN COULD OCCUR AT THE BEGINNING  
IF PRECIPITATION IS ABLE TO RUSH IN BEFORE SFC TEMPERATURES CLIMB  
ABOVE FREEZING THU MORNING. HOWEVER...GIVEN MOST OF THE AREA WILL  
BE IN THE WARM SECTOR AHEAD OF A COLD FRONT THAT DOES NOT ARRIVE  
UNTIL EVENING...MOST OF THE PRECIPITATION SHOULD OCCUR IN THE  
AFTERNOON AND THEREFORE BE OF THE WET VARIETY.  
 
COLDER AIR COMING IN BEHIND THE SYSTEM CHANGES THE RAIN TO SNOW  
SHOWERS BUT THEN QUICKLY CUTS OFF THE PRECIPITATION FROM THE W AS  
THE DRIER AIR MOVES IN. UPSLOPE SNOW SHOWERS DIMINISH ON FRI...AS  
HIGH PRESSURE BUILDS IN FROM THE W...CUTTING OFF THE MOISTURE AND  
UPSLOPE FLOW. THIS SHOULD LEAD TO GOOD RADIATIVE COOLING FRI NT.  
 
ANOTHER SYSTEM AFFECTS THE AREA NEXT WEEKEND. THE MODELS REMAIN  
DIVERSE ON THE NATURE AND EVOLUTION OF THIS SYSTEM...BUT NONE  
ADVERTISE ANYTHING MAJOR...AND ALL SHOW THAT THE OVERALL COLD THEME  
IN A POSITIVE PNA CONTINUES. THUS HAVE THE CHANCE FOR LIGHT SNOW  
SHOWERS.  
 
AT OR VERY CLOSE TO WPC VALUES FOR TEMPERATURES...THEY LOOKED LIKE A  
VERY REASONABLE COMPROMISE BETWEEN THE INORDINATELY COLD AND DRY  
ECMWFHIRES...AND THE GFS BASED GUIDANCE...WHICH SEEMED TOO HIGH  
GIVEN ITS MASS FIELD SOLNS.  
 

 
   
AVIATION /00Z MONDAY THROUGH FRIDAY/
 
 
RADAR IMAGES AND SFC OBS SHOW AREAS OF RAIN MOVING FROM KY AND  
SOUTHERN OH INTO WV AND SOUTHEAST OH THIS EVENING. SFC  
TEMPERATURES ACROSS THE SOUTH STILL IN THE LOW TO MID 40S KEEPING  
PCPN LIQUID. ACROSS THE NORTH...TEMPERATURES ARE IN THE MID TO  
UPPER 30S...AND ARE EXPECTED TO LOWER SOME TONIGHT TO PRODUCE A  
TRANSITION FROM RAIN TO SNOW OVERNIGHT MAINLY AT PKB...CKB...AND  
EKN.  
 
THE CENTER OF A SFC LOW PRESSURE...LOCATED ACROSS CENTRAL KY WILL  
SLOWLY MOVE EAST NORTHEAST INTO WV OVERNIGHT. THIS MOVEMENT WILL  
PRODUCE WINDS TO SHIFT FROM THE SOUTH...TO THE SOUTHEAST AND THEN  
TO THE WEST BY 09Z. COLDER AIR IS EXPECTED BY 12Z AS WINDS SHIFT  
FROM THE NORTHWEST BRINGING SNOW ACROSS THE AREA AND ASSOCIATED  
IFR CONDITIONS. MOUNTAINOUS LOCATIONS SUCH AS KEKN WILL  
GENERALLY BE A RAIN SNOW MIX OR ALL SNOW AFTER 23Z TONIGHT.  
 
EXPECT WIDESPREAD MVFR TO DEVELOP AFTER 00Z...SPREADING FROM EAST  
TO WEST WITH IFR AND LOCAL LIFR AFTER 06-09Z. SOME GENERAL  
IMPROVEMENT TO MVFR EXPECTED ACROSS PARTS OF SOUTHEAST OHIO AND  
NORTHEAST KENTUCKY...GENERALLY AFTER 18Z MONDAY...WHEN SNOW  
SHOWERS WILL MOVE EAST ACROSS WV AS MUCH COLDER AIR RUSHES IN  
UNDER NORTHWEST FLOW. THIS NORTHWEST FLOW WILL PRODUCE UPSLOPE  
SNOW OVER THE NORTHEAST AND CENTRAL MOUNTAINS TO AFFECT EKN AND  
BKW WITH IFR CONDITIONS POSSIBLE THROUGH MONDAY EVENING.  
 
PCPN WILL TAPER OFF LATE MONDAY NIGHT AS MOISTURE RUNS OUT.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...  
 
FORECAST CONFIDENCE: MEDIUM.  
 
ALTERNATE SCENARIO: TIMING PRECIP AND DETERIORATING CONDITIONS MAY  
VARY FROM FORECAST.  
 
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  
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11  
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06  
CRW CONSISTENCY H H M M L L L L M M M M  
HTS CONSISTENCY M M L M L L M M M M M M  
BKW CONSISTENCY H H M M M L L M M M H H  
EKN CONSISTENCY M M H M H H H H L M M M  
PKB CONSISTENCY L L L L M M M M M M M M  
CKB CONSISTENCY L L L L L L M M M M M M  
 
AFTER 00Z TUESDAY...  
IFR POSSIBLE IN SNOW MONDAY NIGHT IN THE NORTHERN AND CENTRAL WV  
MOUNTAINS.  
 

 
   
RLX WATCHES/WARNINGS/ADVISORIES
 
 
WV...NONE.  
OH...WINTER WEATHER ADVISORY UNTIL NOON EST MONDAY FOR OHZ066.  
KY...NONE.  
VA...NONE.  
 

 
 

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