864
FNUS71 KLWX 132111
FWSLWX
SPOT FORECAST FOR POTOMAC RANGER STATION PILES...USFS
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
411 PM EST TUE JAN 13 2026
FORECAST IS BASED ON IGNITION TIME OF 0700 EST ON JANUARY 14.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.
PLEASE CONTACT OUR OFFICE IF YOU HAVE QUESTIONS
OR CONCERNS WITH THIS FORECAST.
DISCUSSION
HIGH PRESSURE WILL CONTINUE OFF THE SOUTHEAST US COAST WEDNESDAY MORNING
WITH A WARM FRONT LIFTING WELL NORTH OF THE AREA. MEANWHILE, A PREFRONTAL
TROUGH WILL CROSS THE AREA WEDNESDAY MORNING INTO WEDNESDAY AFTERNOON BRINGING
A SCATTERED SHOWERS TO THE REGION. A STRONG COLD FRONT WILL QUICKLY FOLLOW
WEDNESDAY EVENING INTO WEDNESDAY NIGHT DELIVERING ADDITIONAL RAIN SHOWERS THAT
WILL CHANGE TO SNOW AS TEMPERATURES FALL. LIMITED ACCUMULATION IS EXPECTED
ALTHOUGH A FLASH FREEZE IS POSSIBLE PENDING ON HOW QUICKLY THE COLD AIR SETTLES
IN.GUSTY WINDS ARE EXPECT THURSDAY INTO FRIDAY AS DRIER CONDITIONS RETURN.
MINIMUM RELATIVE HUMIDITY VALUES WILL FALL INTO THE 45 TO 55 PERCENT RANGE
WEDNESDAY AFTERNOON WITH RECOVERIES BACK INTO THE 70 TO 75 PERCENT RANGE
WEDNESDAY NIGHT INTO THURSDAY MORNING. WINDS WILL REMAIN LIGHT OUT OF THE SOUTH
AND SOUTHWEST AT 5 TO 10 MPH WEDNESDAY MORNING INTO WEDNESDAY AFTERNOON. THESE VALUES
WILL INCREASE WEDNESDAY NIGHT INTO THURSDAY WHILE SWITCHING TO THE NORTHWEST DIRECTION.
EXPECT SUSTAINED WINDS AT 5 TO 15 MPH WITH GUSTS UP TO 30 MPH AT TIMES. GUSTS
OF 30 TO 35 MPH ARE EXPECTED THURSDAY MORNING INTO THURSDAY AFTERNOON IN THE
WAKE OF THE FRONTAL BOUNDARY. THIS WILL LEAD TO MINIMUM RELATIVE HUMIDITY VALUES
IN THE 35 TO 40 PERCENT RANGE THURSDAY AFTERNOON.
PRECIPITATION AMOUNTS THROUGH THE PERIOD WILL REMAIN LESS THAN A TENTH OF
AN INCH.
WEDNESDAY
SKY/WEATHER.........MOSTLY CLOUDY (80-90 PERCENT SHADING). SLIGHT CHANCE OF
RAIN IN THE MORNING, THEN RAIN LIKELY IN THE
AFTERNOON.
CWR.................10 PERCENT INCREASING TO 20 PERCENT LATE IN
THE MORNING, INCREASING TO 70 PERCENT IN
THE AFTERNOON.
CHANCE OF THUNDER...2 PERCENT.
MAX TEMPERATURE.....AROUND 51.
MIN HUMIDITY........61 PERCENT.
WIND (20 FT)........SOUTHWEST WINDS 5 TO 7 MPH.
MIXING HEIGHT.......3700 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 10 TO 17 MPH SHIFTING TO THE WEST 15
TO 21 MPH LATE IN THE MORNING.
SMOKE DISPERSAL.....POOR (11700 KNOT-FT) EARLY IN THE MORNING
INCREASING TO EXCELLENT (66800 KNOT-FT) IN THE
AFTERNOON.
TIME (EST) 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........72 81 76 81 76 80 91 94 95 95 95
WEATHER COV..... SCH SCH SCH SCH CHC LKY LKY LKY CHC
WEATHER TYPE.... RN RN RN RN RN RN RN RN RN
TSTM COV........
CWR.............10 20 10 20 20 20 50 60 70 70 50
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0
TEMP............39 40 42 46 48 49 49 50 51 49 47
RH..............79 79 76 71 68 66 68 66 61 66 65
20 FT WIND DIR..SW SW SW SW SW SW SW SW SW W W
20 FT WIND SPD..6 6 5 6 6 6 6 7 7 6 6
20 FT WIND GUST.10 10 10 12 13 13 13 13 13 13 12
MIX HGT (KFT)...1.3 1.4 1.9 2.9 3.2 3.6 3.7 3.7 3.5 3.3 2.5
TRANSP WIND DIR.W SW SW W W W W W W W W
TRANSP WIND SPD.10 10 10 17 20 21 21 20 20 17 15
VRATE KT-FT/1K..12 13 17 44 54 66 67 63 60 50 33
VENTRATE CAT....PR PR PR FR FR GD GD GD GD FR PR
WEDNESDAY NIGHT
SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT SHADING). CHANCE OF RAIN
EARLY IN THE EVENING, THEN CHANCE OF SNOW LATE
IN THE EVENING. SLIGHT CHANCE OF SNOW
OVERNIGHT.
CWR.................50 PERCENT DECREASING TO 20 PERCENT OVERNIGHT.
CHANCE OF THUNDER...4 PERCENT.
MIN TEMPERATURE.....AROUND 18.
MAX HUMIDITY........73 PERCENT.
WIND (20 FT)........WEST WINDS AROUND 5 MPH EARLY IN THE EVENING
BECOMING LIGHT, THEN BECOMING NORTHWEST 5 TO 12
MPH WITH GUSTS TO AROUND 28 MPH IN THE LATE
EVENING AND OVERNIGHT.
MIXING HEIGHT.......2300 FT AGL.
TRANSPORT WINDS.....NORTHWEST 16 TO 25 MPH INCREASING TO 26 TO 33
MPH OVERNIGHT.
SMOKE DISPERSAL.....EXCELLENT (128900 KNOT-FT) EARLY IN THE EVENING
DECREASING TO GOOD (33600 KNOT-FT) LATE IN THE
NIGHT.
TIME (EST) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........95 96 89 88 86 80 73 67 64 60 57 55
WEATHER COV.....CHC CHC CHC CHC CHC CHC CHC SCH SCH SCH SCH SCH
WEATHER TYPE....RN RN RN RN SN SN SN SN SN SN SN SN
TSTM COV........
CWR.............50 50 50 50 50 50 50 20 20 20 20 20
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0 0
TEMP............45 42 39 36 34 32 29 27 25 23 22 20
RH..............68 73 73 72 69 66 66 63 62 62 59 62
20 FT WIND DIR..W W W W W W NW NW NW NW NW NW
20 FT WIND SPD..5 3 3 5 6 7 7 6 9 9 8 12
20 FT WIND GUST.12 10 10 13 12 15 16 14 21 23 17 28
MIX HGT (KFT)...2.4 2.3 2.4 2.7 3.1 3.6 3.9 4.1 4.3 4.4 4.4 4.3
TRANSP WIND DIR.W W NW NW NW NW NW NW NW NW NW NW
TRANSP WIND SPD.16 18 18 20 25 25 26 29 31 32 33 33
VRATE KT-FT/1K..34 37 39 47 68 79 91 104 117 124 129 126
VENTRATE CAT....PR PR PR FR GD GD GD VGD VGD VGD VGD VGD
THURSDAY
SKY/WEATHER.........MOSTLY SUNNY (40-50 PERCENT SHADING). SLIGHT CHANCE OF
SNOW EARLY IN THE MORNING.
CWR.................20 PERCENT DECREASING TO 10 PERCENT.
CHANCE OF THUNDER...0 PERCENT.
MAX TEMPERATURE.....AROUND 28.
MIN HUMIDITY........42 PERCENT.
WIND (20 FT)........WEST WINDS 10 TO 13 MPH WITH GUSTS TO AROUND 29
MPH.
MIXING HEIGHT.......4900 FT AGL.
TRANSPORT WINDS.....NORTHWEST 26 TO 32 MPH.
SMOKE DISPERSAL.....EXCELLENT (108700 KNOT-FT).
TIME (EST) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........54 52 53 53 54 53 51 50 46 43 39 37
WEATHER COV.....SCH
WEATHER TYPE....SN
TSTM COV........
CWR.............20 10 10 10 10 10 10 0 0 0 0 0
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0 0
TEMP............19 19 19 21 22 23 25 26 26 26 26 25
RH..............61 59 59 54 52 50 46 44 44 42 42 44
20 FT WIND DIR..W W W NW NW NW W W W W W W
20 FT WIND SPD..12 10 13 13 10 13 13 13 13 13 13 12
20 FT WIND GUST.29 21 29 29 23 26 24 23 24 25 25 24
MIX HGT (KFT)...4.2 4.1 4.2 4.3 4.5 4.6 4.7 4.7 4.8 4.9 4.8 4.5
TRANSP WIND DIR.NW NW NW NW NW NW NW NW NW W W W
TRANSP WIND SPD.32 32 31 31 30 29 28 26 28 29 30 30
VRATE KT-FT/1K..117 114 112 117 117 115 112 109 116 123 126 118
VENTRATE CAT....VGD VGD VGD VGD VGD VGD VGD VGD VGD VGD VGD VGD
FORECASTER...TAYLOR
REQUESTED BY...ROBERT CUMMINGS
TYPE OF REQUEST...PRESCRIBED
.TAG 2600061.0/LWX
.DELDT 01/13/26
.FORMATTERVERSION 2.0.0
.EMAIL ROBERT.CUMMINGS@USDA.GOV
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