459  
FXUS61 KLWX 141855  
AFDLWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
255 PM EDT TUE AUG 14 2018  
   
SYNOPSIS
 
 
UPPER LEVEL LOW OVER NORTHEAST PENNSYLVANIA WILL CONTINUE  
LIFTING NORTHEAST AWAY FROM THE REGION TONIGHT. UPPER LEVEL  
RIDGE WILL BUILD OVER THE REGION WEDNESDAY AND THURSDAY. A COLD  
FRONT WILL MOVE INTO THE AREA AT WEEK'S END.  
 

 
   
NEAR TERM /THROUGH WEDNESDAY/
 
 
UPPER LOW TO OUR NORTHEAST IS SLOWLY BUT SURELY PULLING AWAY AT  
PRESENT. RIDGE OF HIGH PRESSURE WILL GRADUALLY BUILD EAST  
TONIGHT AND WEDNESDAY. LINGERING MOISTURE AND UPPER LEVEL  
ENERGY ROTATING AROUND THE LOW IS HELPING SPAWN A FEW MORE  
SHOWERS AND T-STORMS, BUT THESE SHOULD BE WEAKER THAN THE LAST  
FEW DAYS GIVEN MINIMAL CAPE AND SHEAR. CAN'T RULE OUT A SEVERE  
STORM BUT ODDS ARE MUCH LESS COMPARED TO YESTERDAY AND THE DAY  
BEFORE, WHILE FLOOD THREAT SEEMS TO HAVE DROPPED TO NEAR ZERO.  
UPPER LEVEL ENERGY MAY KEEP A FEW STORMS GOING PAST SUNSET BUT  
ALL STORMS SHOULD BE DONE BY MIDNIGHT. THE OVERNIGHT SHOULD BE  
DRY, WITH PERHAPS A LITTLE PATCHY FOG, AND TEMPS FALLING BACK  
INTO THE 60S ACROSS THE AREA.  
 
WEDNESDAY, ANY PATCHY FOG WILL DISSIPATE QUICKLY, AND THE DAY  
WILL BE MOSTLY SUNNY AREA-WIDE. HIGHS WILL REBOUND WITH THE  
RIDGE BUILDING OVERHEAD, WITH TEMPS APPROACHING IF NOT REACHING  
90.  
 

 
   
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/
 
 
UPPER LEVE DISTURBANCES OUT AHEAD OF THE MAIN SYSTEM START  
MOVING ACROSS THE REGION LATE WEDNESDAY NIGHT AND THURSDAY.  
INSTABILITY WILL BUILD THURSDAY WITH TEMPS AGAIN NEAR 90, SO  
SOME ISOLATED THUNDERSTORMS CAN'T BE RULED OUT, BUT ODDS FAVOR  
THE MOUNTAINS OVER THE METRO. STORMS THAT ARE HOME GROWN WILL  
LIKELY DIE OUT LATER THURSDAY NIGHT, BUT ADDITIONAL  
SHOWER/STORMS MAY MOVE IN FROM THE WEST OVERNIGHT. LOWS WILL BE  
WARMER, WITH READINGS STAYING CLOSER TO 70.  
 

 
   
LONG TERM /FRIDAY THROUGH TUESDAY/
 
 
A COLD FRONT WILL BE APPROACHING AND MOVING ACROSS OUR AREA ON  
FRIDAY. THIS WILL BRING AN INCREASE IN THE CHANCE OF SHOWERS AND  
THUNDERSTORMS OVER OUR CWA, MAINLY IN THE AFTERNOON/EVENING  
HOURS. GUIDANCE SUGGESTS THAT THE FRONT WILL STALL JUST TO OUR  
SOUTH THROUGH THE WEEKEND WHILE WAVES OF LOW PRESSURE TRACK  
THROUGH IT, ALONG WITH PULSES OF ENERGY ALOFT. THIS WILL ALLOW  
FOR ADDITIONAL DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER OUR  
AREA. THIS FRONTAL BOUNDARY WILL MOVE AWAY FROM OUR AREA LATE  
ON SUNDAY. A LOW PRESSURE THAT WILL BE TRACKING NORTHEAST  
THROUGH THE GREAT LAKES WILL LIFT A WARM FRONT OVER US ON  
MONDAY, FOLLOWED BY AN APPROACHING COLD FRONT ON TUESDAY,  
CONTINUING THE CHANCE FOR SHOWERS AND THUNDERSTORMS, MAINLY IN  
THE AFTERNOON/EVENING.  
 

 
   
AVIATION /19Z TUESDAY THROUGH SUNDAY/
 
 
GENERALLY VFR THRU THE NEXT 72 HOURS ALL TERMINALS. PATCHY FOG  
CAN'T BE RULED OUT AT MRB/CHO NEXT COUPLE OF MORNINGS, BUT  
ODDS ARE NOT HIGH NOW THAT THE AIR MASS HAS DRIED OUT A BIT.  
MAIN CONCERN THIS AFT/EVE WILL BE SCATTERED SHOWERS/T-STORMS  
WHICH COULD PRODUCE BRIEF REDUCTIONS OF CIGS/VIS AND A FEW WIND  
GUSTS UP TO 30 KNOTS. WEDNESDAY AND THURSDAY LOOK CONVECTIVELY  
QUIET.  
 
PERIODS OF SUB-VFR CONDITIONS ARE POSSIBLE FRIDAY THROUGH  
SUNDAY DUE TO POSSIBLE SHOWERS AND THUNDERSTORMS DUE TO A  
FRONTAL BOUNDARY MOVING ACROSS AND THEN STALLING NEAR OUR AREA.  
 

 
   
MARINE
 
 
WINDS HAVE INCREASED A BIT IN THE WAKE OF THE DEPARTING LOW. A  
FEW GUSTS MAY REACH 18-20 KNOTS. IN ADDITION, SCATTERED SHOWERS  
AND T-STORMS WILL CROSS THE WATERS, BUT MOST WILL BE RELATIVELY  
WEAK, WITH WINDS BELOW GALE FORCE. THEREFORE, DECIDED TO ISSUE A  
SCA FOR THIS AFT AND EVENING TO COVER THE THREAT OF 20-30 KNOT  
GUSTS. THINK ANY SHOWERS/STORMS SHOULD STAY BELOW 34 KNOTS BUT  
ITS NOT IMPOSSIBLE A SPECIAL MARINE WARNING BECOMES NECESSARY.  
 
LATE TONIGHT THROUGH THURSDAY NIGHT SHOULD BE DRY WITH WEAKER  
WINDS AND NO SHOWER/T-STORM ACTIVITY AS A RIDGE OF HIGH PRESSURE  
DOMINATES.  
 
WIND GUSTS MAY REACH SMALL CRAFT CRITERIA ON FRIDAY AS A FRONT  
MOVES THROUGH OUR AREA. THE FRONT WILL STALL NEAR OUR AREA  
THROUGH SUNDAY. SHOWERS AND THUNDERSTORMS ARE POSSIBLE THROUGH  
THIS TIME WHICH MAY BRING GUSTY WINDS AT TIME.  
 

 
   
LWX WATCHES/WARNINGS/ADVISORIES
 
 
DC...NONE.  
MD...NONE.  
VA...NONE.  
WV...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ530>543.  
 

 
 

 
SYNOPSIS...RCM  
NEAR TERM...RCM  
SHORT TERM...RCM  
LONG TERM...IMR  
AVIATION...IMR/RCM  
MARINE...IMR/RCM  
 
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