998  
FXUS61 KRLX 200901  
AFDRLX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON WV  
401 AM EST THU FEB 20 2020  
   
SYNOPSIS
 
 
LOW PRESSURE PASSES SOUTH OF THE AREA TODAY. STRONG HIGH  
PRESSURE DOMINATES FRIDAY THROUGH THE WEEKEND, WHICH STARTS COLD  
AND THEN MODERATES. LOW PRESSURE MONDAY AND AGAIN MIDWEEK.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
AS OF 145 AM THURSDAY...  
 
SLIGHT NORTHWARD PUSH TO THE PRECIPITATION SHIELD AS SEE IN THE  
MIDLEVEL DEFORMATION ZONE AROUND THE 18Z TIME FRAME, AND HAVE  
ADJUSTED THOSE POPS ACCORDINGLY. STILL LARGELY ON THE NORTHERN  
FRINGE OF THIS BROAD PRECIPITATION SHIELD THAT WILL AFFECT CWAS  
FURTHER SOUTH MORE THAN OURS. TEMPERATURES MARGINAL, WITH MID  
30S IN THE FORECAST AROUND PRECIPITATION ARRIVAL TIME AND FOR  
DAYTIME MAX VALUES, SO POCKETS SOUTH OF THE AFOREMENTIONED  
DEFORMATION ZONE MAY FIND THEMSELVES IN RAIN OR A RAIN/SNOW MIX.  
THINK THE BULK OF THE MOS GUIDANCE IS TOO WARM GIVEN THE  
NORTHERLY WIND FLOW AD THE COLD HIGH PRESSURE IN PLACE SO THE  
VALUES IN THE FORECAST ARE HUGGING THE LOWER SIDE OF GUIDANCE.  
THE BEST CHANCES FOR ACCUMULATING SNOW IS GOING TO BE THE ON THE  
SOUTHERN EDGES OF OUR TWO VA COUNTIES. COULD SEE A TOUCH OVER  
AN INCH IN THESE AREAS, WHILE ANYWHERE ELSE IN THE SHIELD OF  
POPS WILL BE LESS THAN AN INCH. THE DURATION OF THIS  
PRECIPITATION IS FAIRLY LIMITED, FROM 15Z TO AROUND 22Z BEFORE  
THE POPS COME BACK BELOW 15. NO ADVISORY PLANNED AS SNOW DOES  
NOT MEET 12 HOUR ADVISORY CRITERIA. CLEARING EXPECTED OVERNIGHT  
WILL CHILLY READINGS EXPECTED, BUT NOT UN-FEBRUARY LIKE BY ANY  
MEANS.  
 

 
   
SHORT TERM /FRIDAY THROUGH SUNDAY/
 
 
AS OF 345 AM THURSDAY...  
   
..DRY WEEKEND ON TAP
 
 
A LARGE HIGH PRESSURE SYSTEM SLOWLY WEAKENS AS IT CROSSES THE  
AREA THIS PERIOD. THE HIGH REPRESENTS A MODIFYING ARCTIC AIR  
MASS THAT CONSERVES ITS LOW DEW POINTS MUCH MORE THAN THE  
TEMPERATURES. TEMPERATURES START OUT BELOW NORMAL, AND THEN RISE  
SEVERAL DEGREES PER DAY, GETTING ABOVE NORMAL FOR SUNDAY  
AFTERNOON. ADJUSTED CENTRAL GUIDANCE LOWS DOWN IN THE VALLEYS  
GIVEN CLEAR, CALM CONDITIONS. THERE MAY BE STRATOCU IN AND NEAR  
THE MOUNTAINS FIRST THING FRIDAY MORNING BUT, WITH VERY DRY AIR  
ARRIVING, THESE CLOUDS SHOULD MIX OUT QUICKLY, AND THEN THERE  
SHOULD BE NARY A CLOUD UNTIL SOME CIRRUS ARRIVES ON SUNDAY, AS  
UPPER LEVEL RIDGING FLATTENS.  
 
AFTERNOON RH VALUES WILL DROP INTO THE 20S AND 30S, WITH  
SATURDAY BEING THE DRIEST, WITH WIDESPREAD 20S, EVEN TEENS IN  
THE MOUNTAINS. THE COOL WEATHER AND LIGHT FLOW SHOULD KEEP THE  
FIRE DANGER MINIMAL, THOUGH. RH VALUES AT LEAST THIS LOW IN  
THIS TYPE OF PATTERN THIS TIME OF YEAR IS A HIGH CONFIDENCE  
FORECAST, AND ACTUAL VALUES MAY TURN OUT TO BE EVEN LOWER.  
 

 
   
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/
 
 
AS OF 345 AM THURSDAY...  
   
..FOLLOWED BY ANOTHER ACTIVE WEEK
 
 
A SOUTHERN STREAM TROUGH AND LOW PRESSURE SYSTEM APPROACH  
SUNDAY NIGHT, AND THEN THE SURFACE LOW TRACKS NORTH OF THE AREA  
MONDAY THROUGH MONDAY NIGHT. CLOUDS WILL BE ON THE INCREASE  
SUNDAY NIGHT, AND RAIN WILL OVERSPREAD THE AREA QUICKLY MONDAY  
MORNING, MAKING FOR ANOTHER WET START TO THE WORK WEEK, IN THE  
WARM ADVECTION AHEAD OF THE SYSTEM. THE COLUMN MAY WET-BULB COOL  
ENOUGH FOR WET SNOW TO BE IN THE MIX OVERNIGHT SUNDAY NIGHT  
ACROSS THE NORTH, BUT THIS WILL BE PRIMARILY A RAIN EVENT. THE  
WET WEATHER CONTINUES MONDAY NIGHT, AHEAD OF THE COLD FRONT  
THAT EVENTUALLY CROSSES, AND OF THE APPROACHING SHORT WAVE.  
 
MODELS DIFFER ON HOW QUICKLY THE SYSTEM PULLS OUT ON TUESDAY,  
BUT A SECOND SOUTHERN STREAM TROUGH DROPS DOWN AS THE FIRST  
LIFTS OUT, AND THEN A NORTHERN STREAM SHORT WAVE TROUGH DROPS  
IN, AS AN AMPLIFYING LONG WAVE TROUGH SETS UP SHOP OVER THE  
EASTERN U.S. MID TO LATE WEEK.  
 
THE SECOND SOUTHERN STREAM SHORT WAVE BRINGS A GOOD CHANCE FOR  
RAIN WEDNESDAY. PRECIPITATION SHOULD TRANSITION TO SNOW OR SNOW  
SHOWERS SOMETIME WEDNESDAY NIGHT, BUT THE TIMING, AND COVERAGE,  
WILL DEPEND UPON WHERE LOW PRESSURE FORMS AND TRACKS, AND HOW  
QUICKLY IT INTENSIFIES. NEXT THURSDAY SHOULD, AT THE LEAST,  
BRING NORTHWEST LOW LEVEL FLOW GIVEN LOW PRESSURE EAST OR  
NORTHEAST OF THE AREA BY THEN, BENEATH DEEP TROUGHING ALOFT.  
THIS WOULD SPELL NUMEROUS SNOW SHOWERS, BUT DAYTIME TEMPERATURES  
MAY STILL LIMIT ACCUMULATIONS ACROSS THE LOWLANDS.  
 
NO CHANGES WERE MADE TO CENTRAL GUIDANCE TEMPERATURES, WHICH  
DROP BACK BELOW NORMAL AT THE END.  
 

 
   
AVIATION /09Z THURSDAY THROUGH MONDAY/
 
 
AS OF 1225 AM THURSDAY...  
 
CRW, HTS, PKB, CKB, AND EKN ALL VFR AND PRECIPITATION FREE  
THROUGH THE PERIOD. EACH SITE WILL SEE A VARYING DEGREE OF  
CEILING LOWERING FROM A SOUTHERN STREAM LOW PRESSURE SYSTEM.  
 
BKW IS ANOTHER STORY, AND WILL GET INTO A BRIEF PERIOD OF SNOW.  
WILL UTILIZE A FEW HOURS OF 2SM -SN AND CEILINGS TOUCHING MVFR,  
BUT THE BULK OF THE PRECIPITATION FROM THIS SYSTEM WILL BE TO  
THE SOUTH OF AREA. THE BKW TERMINAL LIES ON THE NORTHERN FRINGE  
OF THE MOISTURE THAT IS DEEP ENOUGH FOR PRECIPITATION, AND SOME  
LIGHT ACCUMULATION IS NOT OUT OF THE QUESTION.  
 
WINDS LESS THAN 12KTS ACROSS THE BOARD.  
 
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...  
 
FORECAST CONFIDENCE: HIGH.  
 
ALTERNATE SCENARIOS: SOME TIMING ADJUSTMENTS FOR SNOW AT BKW MAY  
BE NEEDED.  
 
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 02/20/20  
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20  
EST 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15  
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 L H M  
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 06Z FRIDAY...  
NO WIDESPREAD IFR CONDITIONS EXPECTED AT THIS TIME.  
 

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

 
 

 
SYNOPSIS...26/TRM  
NEAR TERM...26  
SHORT TERM...TRM  
LONG TERM...TRM  
AVIATION...26  
 
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