Spot Forecast
Issued by NWS Sterling, VA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 
000
FNUS71 KLWX 180858
FWSLWX

Spot Forecast for Buck Mountain...USFS
National Weather Service Baltimore MD/Washington DC
458 AM EDT Thu Apr 18 2024

Forecast is based on ignition time of 0500 EDT on April 18.
If conditions become unrepresentative...contact the National Weather
Service.

Please contact our office if you have questions
or concerns with this forecast.

.DISCUSSION...
Skies remain mostly cloudy this morning with any threat for
additional showers having ended. Mild conditions are in place with
good nighttime recoveries. A weak cold front tracks through by
miday which leads to a shift to northwest winds for this
afternoon. Deep mixing in the lower atmosphere will yield
increasing mixing heights (on the order of 5,000 to 5,500 feet
this afternoon). Winds eventually shift to northeast to east by
later in the evening and into the night. This raises humidity
levels after daytime RH values around 30 to 35 percent.

The next system brings a chance for wetting rains on Friday. There
is also a slight chance for thunderstorms with this activity.
Total rainfall amounts are expected to be around 0.20 to 0.30
inches. In the wake of this frontal system, a dry and gusty
northwest wind is in the forecast for Saturday. Gusts could
approach 25 to 30 mph with daytime RH values around 30 percent.


.REST OF TONIGHT...

Sky/weather.........Mostly cloudy (45-55 percent).
CWR.................0 percent.
Min temperature.....Around 57.
Max humidity........83 percent.
Eye level winds.....West winds around 5 mph.
Wind (20 ft)........West winds around 8 mph.
Transport winds.....Northwest around 15 mph.
Smoke dispersal.....Fair (17700 knot-ft).
Haines Index........3 or very low potential for large plume
                    dominated fire growth.

TIME (EDT)      5AM
Sky (%).........51
Weather cov.....
Weather type....
Tstm cov........
CWR.............0
Temp............59
RH..............78
20 FT wind dir..W
20 FT wind spd..8
20 FT wind gust.12
Eye lvl wnd dir.W
Eye lvl wnd spd.5
Eye lvl wnd gst.7
Transp wind dir.NW
Transp wind spd.15
Haines index....3
Vrate kt-ft/1K..18
Ventrate Cat....PR

.TODAY...

Sky/weather.........Mostly sunny (30-40 percent).
CWR.................0 percent.
Max temperature.....Around 74.
Min humidity........34 to 37 percent.
Eye level winds.....Northwest winds up to 6 mph.
Wind (20 ft)........Northwest winds 7 to 10 mph, gusts up to 17 mph.
Transport winds.....Northwest 14 to 16 mph.
Smoke dispersal.....Fair (17400 knot-ft) early in the morning
                    increasing to excellent (63900 knot-ft) in the
                    afternoon.
Haines Index........3 to 4 or very low to low potential for large
                    plume dominated fire growth.

TIME (EDT)      6 AM   8 AM   10 AM  NOON   2 PM   4 PM
Sky (%).........52     55     46     31     11     12
Weather cov.....
Weather type....NONE   NONE   NONE   NONE   NONE   NONE
Tstm cov........
CWR.............0      0      0      0      0      0
Temp............58     58     63     68     71     73
RH..............77     72     65     50     42     38
20 ft wind......W 7    W 8    NW 10  NW 10  NW 10  NW 10
20 ft wind gust.12     16     17     17     16     16
Eye level wind..W 4    W 5    NW 6   NW 6   NW 6   NW 6
Eye lvl wnd gst.7      10     10     10     10     10
Transport wind..NW 15  NW 14  NW 15  NW 15  W 14   NW 16
Haines index....3      3      4      4      4      4
Vrate kt-ft/1K..17     21     45     59     55     64
Ventrate Cat....POOR   POOR   FAIR   FAIR   FAIR   GOOD

.TONIGHT...

Sky/weather.........Mostly clear (20-30 percent) then becoming
                    mostly cloudy (50-60 percent).
CWR.................10 percent.
Min temperature.....Around 50.
Max humidity........86 percent.
Eye level winds.....Northwest winds up to 5 mph early in the
                    evening becoming light.
Wind (20 ft)........Northwest winds around 8 mph decreasing to 5 mph
                    early in the evening, then becoming light in the
                    late evening and overnight.
Transport winds.....North 8 to 15 mph shifting to the southeast 1
                    to 6 mph in the late evening and overnight.
Smoke dispersal.....Good (49900 knot-ft) early in the evening
                    decreasing to poor (0 knot-ft) late in the
                    night.
Haines Index........4 to 5 or low to moderate potential for large
                    plume dominated fire growth.

TIME (EDT)      6 PM   8 PM   10 PM  MIDNGT 2 AM   4 AM
Sky (%).........10     5      12     21     32     52
Weather cov.....
Weather type....NONE   NONE   NONE   NONE   NONE   NONE
Tstm cov........
CWR.............0      0      0      0      0      0
Temp............72     64     60     57     53     51
RH..............39     52     60     69     77     83
20 ft wind......NW 8   N 5    NE 3   E 3    SE 3   SE 3
20 ft wind gust.13     6      5      5      5      5
Eye level wind..NW 5   N 3    NE 2   E 2    SE 2   SE 2
Eye lvl wnd gst.8      4      3      3      3      3
Transport wind..NW 15  N 12   E 3    SE 1   SE 2   SE 5
Haines index....4      5      4      4      4      4
Vrate kt-ft/1K..50     24     2      0      0      1
Ventrate Cat....FAIR   POOR   POOR   POOR   POOR   POOR

.FRIDAY...

Sky/weather.........Mostly cloudy (75-85 percent). Rain showers
                    likely in the morning, then rain showers and
                    slight chance of thunderstorms in the
                    afternoon.
CWR.................10 percent increasing to 30 percent early in
                    the morning, then increasing to 60 percent late
                    in the morning increasing to 80 percent late in
                    the afternoon decreasing to 60 percent.
Max temperature.....Around 69.
Min humidity........63 percent.
Eye level winds.....Light winds becoming south up to 5 mph early in
                    the morning, then shifting to the southwest
                    around 4 mph late in the afternoon.
Wind (20 ft)........Light winds becoming south 5 to 8 mph early in
                    the morning, then shifting to the southwest
                    around 6 mph late in the afternoon. Gusty and
                    erratic winds expected near thunderstorms late
                    in the afternoon.
Transport winds.....South 7 to 15 mph decreasing to around 9 mph
                    late in the afternoon.
Smoke dispersal.....Poor (1800 knot-ft) early in the morning
                    increasing to fair (18400 knot-ft) in the
                    afternoon.
Haines Index........2 to 4 or very low to low potential for large
                    plume dominated fire growth.

TIME (EDT)      6 AM         10 AM        2 PM
Sky (%).........68           85           87
Weather cov.....             CHANCE       DEFNTE
Weather type....NONE         RNSHWR       RNSHWR
Tstm cov........                          S CHC
CWR.............10           30           80
Temp............50           57           66
RH..............86           77           63
20 FT wind......SE 3G6       S 6G10       S 7G12
Eye level wind..SE 2G4       S 4G6        S 4G7
Transport wind..SE 7         S 14         S 13
Haines index....4            3            2
Vrate kt-ft/1K..2            13           16
Ventrate Cat....POOR         POOR         POOR

$$
Forecaster...Rubin-Oster
Requested by...Collett
Type of request...PRESCRIBED
.TAG 2411261.0/LWX
.DELDT 04/18/24
.FormatterVersion 2.0.0
.EMAIL Jay.Collett@usda.gov
USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.