FNUS74 KHUN 131243 FWSHUN SPOT FORECAST FOR COLBERT FERRY WEST...NATIONAL PARK SERVICE NATIONAL WEATHER SERVICE HUNTSVILLE AL 643 AM CST FRI FEB 13 2009 FORECAST IS BASED ON IGNITION TIME OF 1000 CST ON FEBRUARY 13. IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION... MOSTLY HIGH CLOUDS WILL BE PRESENT THIS MORNING...BUT EXPECTING A GRADUAL INCREASE IN MID-LEVEL CLOUD COVER DURING THE AFTERNOON AS A LOW PRESSURE SYSTEM APPROACHES THE REGION FROM THE WEST. RELATIVE HUMIDITY VALUES WILL FALL NEAR 30 PERCENT THIS AFTERNOON DURING PEAK MIXING AND HEATING THIS AFTERNOON. WINDS WILL GENERALLY BE LIGHT SOUTHEASTERLY TODAY AND TONIGHT AHEAD OF THE LOW...ALLOWING FOR FAIRLY LOW DISPERSION RATES. RAIN WILL BEGIN TO MOVE INTO THE AREA AHEAD OF A COLD FRONT AROUND 2 AM CST...BUT CONFIDENCE IN TIMING REMAINS LOW. THE COLD FRONT WILL CROSS THE AREA BY ABOUT 9 AM CST...RESULTING IN A WIND SHIFT FROM THE NORTH AND BRINGING AN END TO ANY PRECIPITATION. HOWEVER...LOW CLOUDS ARE EXPECTED TO LINGER ACROSS THE AREA INTO THE AFTERNOON. DUE TO THE RELATIVELY LIGHT WINDS...DISPERSION VALUES WILL CONTINUE TO BE LOW. .TODAY... SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT). SLIGHT CHANCE OF RAIN IN THE AFTERNOON. TEMPERATURE.........52 AT IGNITION...MAX 66. RH..................53 PERCENT AT IGNITION...MIN 30 PERCENT. WIND (20 FT)........WINDS SOUTHEAST AT 4 MPH AT IGNITION...OTHERWISE LIGHT WINDS BECOMING SOUTHEAST AROUND 5 MPH IN THE AFTERNOON. CWR.................10 PERCENT INCREASING TO 20 PERCENT IN THE AFTERNOON. MIXING HEIGHT.......1000 FT AGL AT IGNITION...OTHERWISE 200-1000 FT AGL INCREASING TO 4400-4700 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....SOUTHEAST 5 TO 6 MPH INCREASING TO 6 TO 7 MPH IN THE AFTERNOON. TIME (CST) 10 AM NOON 2 PM 4 PM SKY (%).........MCLDY MCLDY MCLDY MCLDY WEATHER COV..... S CHC S CHC S CHC WEATHER TYPE....NONE RAIN RAIN RAIN TEMP............52 60 65 65 RH..............53 37 31 31 20 FT WIND......SE 3 SE 5 SE 5 SE 5 MIX HGT (FT)....1000 4700 4700 4400 TRANSPORT WIND..SE 6 S 7 S 7 SE 6 DISPERSION IDX..4 28 28 22 CHC OF PCPN (%).10 20 20 20 .TONIGHT... SKY/WEATHER.........CLOUDY (90-100 PERCENT). CHANCE OF RAIN IN THE EVENING...THEN RAIN LIKELY AFTER MIDNIGHT. TEMPERATURE.........MIN 50. RH..................MAX 84 PERCENT. WIND (20 FT)........SOUTHEAST WINDS AROUND 5 MPH BECOMING SOUTHWEST. CWR.................70 PERCENT. MIXING HEIGHT.......400-1500 FT AGL. TRANSPORT WINDS.....SOUTHEAST 7 TO 10 MPH SHIFTING TO THE SOUTH 14 TO 17 MPH AFTER MIDNIGHT. TIME (CST) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM SKY (%).........MCLDY MCLDY MCLDY CLOUDY CLOUDY CLOUDY WEATHER COV.....CHANCE CHANCE CHANCE LIKELY LIKELY LIKELY WEATHER TYPE....RAIN RAIN RAIN RAIN RAIN RAIN TEMP............61 57 55 53 52 51 RH..............37 46 55 65 74 80 20 FT WIND......SE 5 SE 5 S 5 S 3 S 5 SW 5 MIX HGT (FT)....1100 1100 400 1400 1400 1500 TRANSPORT WIND..SE 10 SE 10 SE 7 S 17 S 17 S 14 DISPERSION IDX..13 13 0 12 12 9 CHC OF PCPN (%).40 40 40 70 70 70 .SATURDAY... SKY/WEATHER.........PARTLY SUNNY (60-70 PERCENT). TEMPERATURE.........MAX 61. RH..................MIN 50 PERCENT. WIND (20 FT)........SOUTHWEST WINDS AROUND 5 MPH BECOMING NORTH 5 TO 7 MPH IN THE LATE MORNING AND AFTERNOON. CWR.................10 PERCENT. MIXING HEIGHT.......1200-1800 FT AGL INCREASING TO 4000-4100 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....SOUTHWEST AROUND 8 MPH SHIFTING TO THE NORTHWEST IN THE LATE MORNING AND AFTERNOON. TIME (CST) 6 AM 8 AM 10 AM NOON 2 PM 4 PM SKY (%).........MCLDY MCLDY MCLDY MCLDY MCLDY MCLDY WEATHER COV..... WEATHER TYPE....NONE NONE NONE NONE NONE NONE TEMP............50 52 56 59 60 60 RH..............84 81 72 62 54 50 20 FT WIND......W 3 W 3 W 5 NW 7 NW 6 N 6 MIX HGT (FT)....1200 1200 1800 4000 4000 4100 TRANSPORT WIND..SW 8 SW 8 W 12 NW 13 NW 13 NW 13 DISPERSION IDX..5 5 8 35 35 35 CHC OF PCPN (%).10 10 10 10 10 10 $$ FORECASTER...WHITE REQUESTED BY...SHAWN NAGLE TYPE OF REQUEST...PRESCRIBED .TAG 20090213.COLBE.01/HUN