517  
FNUS71 KLWX 211441  
FWSLWX  
 
SPOT FORECAST FOR MS2A, 2CS...DEP  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
1041 AM EDT FRI SEP 21 2018  
 
FORECAST IS BASED ON IGNITION TIME OF 1000 EDT ON SEPTEMBER 21.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION
 
 
HIGH PRESSURE WILL SHIFT OFFSHORE TODAY AHEAD OF AN APPROACHING  
COLD FRONT. THE FRONT WILL CROSS INTO THE REGION FROM THE  
NORTHWEST TONIGHT, PUSH SOUTHWARD ON SATURDAY, AND STALL NEAR THE  
REGION THROUGH MONDAY. THIS WILL BEING COOL, WET WEATHER TO THE  
AREA SUNDAY AND MONDAY. THE FRONT WILL RETURN NORTHWARD NEXT WEEK  
BRINGING ADDITIONAL UNSETTLED WEATHER.  
   
TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLOUDY (60-70 PERCENT) THEN BECOMING  
PARTLY CLOUDY (45-55 PERCENT) THEN BECOMING  
MOSTLY CLOUDY (60-70 PERCENT). SCATTERED  
THUNDERSTORMS LATE IN THE EVENING. SCATTERED  
SHOWERS LATE IN THE EVENING, THEN ISOLATED  
SHOWERS EARLY IN THE MORNING.  
CWR.................10 PERCENT INCREASING TO 30 PERCENT LATE IN THE  
EVENING, THEN INCREASING TO 50 PERCENT  
OVERNIGHT DECREASING TO 20 PERCENT EARLY IN THE  
MORNING.  
MIN TEMPERATURE.....AROUND 65.  
MAX HUMIDITY........100 PERCENT.  
WIND (20 FT)........WEST WINDS 5 TO 10 MPH. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS LATE IN THE  
EVENING.  
MIXING HEIGHT.......100-1100 FT AGL.  
TRANSPORT WINDS.....SOUTHWEST 12 TO 20 MPH SHIFTING TO THE WEST 7  
TO 8 MPH AFTER 3 AM.  
SMOKE DISPERSAL.....POOR TO FAIR (9300-17600 KNOT-FT) DECREASING TO  
POOR (1000 KNOT-FT) EARLY IN THE EVENING.  
 
TIME (EDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM  
SKY (%).........66 49 51 55 65 76  
WEATHER COV..... SCTTRD SCTTRD SCTTRD  
WEATHER TYPE....NONE NONE NONE RNSHWR RNSHWR RNSHWR  
CWR.............10 10 10 30 50 50  
TEMP............73 70 69 68 67 67  
RH..............84 93 97 100 100 100  
20 FT WIND......S 10 S 10 S 9 S 8 SW 6 W 5  
20 FT WIND GUST.20 18 17 15 12 9  
MIX HGT (FT)....1100 300 200 200 300 100  
MIXNG WIND......S 20 S 14 S 14 S 14 SW 14 W 8  
VRATE KT-FT/100018 4 2 3 3 1  
   
SATURDAY
 
 
SKY/WEATHER.........PARTLY SUNNY (55-65 PERCENT). ISOLATED SHOWERS  
EARLY IN THE MORNING.  
CWR.................20 PERCENT DECREASING TO 10 PERCENT EARLY IN  
THE MORNING.  
MAX TEMPERATURE.....AROUND 71.  
MIN HUMIDITY........61 PERCENT.  
WIND (20 FT)........NORTH WINDS 6 TO 9 MPH.  
MIXING HEIGHT.......600-2500 FT AGL INCREASING TO 2800-3300 FT AGL  
IN THE AFTERNOON.  
TRANSPORT WINDS.....NORTHWEST 12 TO 17 MPH SHIFTING TO THE NORTH  
LATE IN THE AFTERNOON.  
SMOKE DISPERSAL.....POOR TO FAIR (5300-15000 KNOT-FT) INCREASING TO  
FAIR TO GOOD (27800-37300 KNOT-FT) EARLY IN THE  
MORNING.  
 
TIME (EDT) 6 AM 9 AM NOON 3 PM  
SKY (%).........74 53 42 51  
WEATHER COV.....ISOLTD  
WEATHER TYPE....RNSHWR NONE NONE NONE  
CWR.............20 10 10 10  
TEMP............66 67 70 70  
RH..............100 81 63 63  
20 FT WIND......NW 6G12 N 8G16 N 8G17 N 6G13  
MIX HGT (FT)....600 1800 2500 3200  
MIXNG WIND......W 12 N 22 N 17 N 13  
VRATE KT-FT/10005 34 37 36  
 

 
FORECASTER...WITT  
REQUESTED BY...JOLEEN DUDLEY  
TYPE OF REQUEST...PRESCRIBED  
.TAG 1816056.0/LWX  
.DELDT 09/21/18  
 
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