Area Forecast Discussion
Issued by NWS Birmingham, AL

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FXUS64 KBMX 020007
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
607 PM CST SUN FEB 1 2015

.UPDATE...
MESOSCALE UPDATE AND AVIATION.

&&

.DISCUSSION...

LINE OF SHOWERS AND THUNDERSTORMS ALONG A COLD FRONT WAS JUST
ENTERING NORTHWEST ALABAMA AND EXTENDED SOUTHWEST TOWARD JACKSON
MISSISSIPPI. THE LINE WAS MOVING RATHER QUICKLY AROUND 50 MPH.
0-6KM BULK SHEAR VALUES WERE AROUND 50KTS WHILE LOW LEVEL
HELICITIES WERE AROUND 250. SURFACE BASED CAPE VALUES WERE AROUND
500 IN A SMALL AREA APPROACHING SOUTHWESTERN ALABAMA...BUT
DECREASING. THEREFORE...STILL EXPECT A DECREASE IN INTENSITY AS
CAPE DECREASES FURTHER...BUT AN ISOLATED DAMAGING WIND GUSTS IS
NOT OUT OF THE QUESTION FOR
SUMTER...GREENE...HALE...MARENGO...PERRY...BIBB AND DALLAS
COUNTIES THE NEXT FEW HOURS. OTHERWISE...UPDATED FOR RADAR AND
TEMPERATURE TRENDS.

75

&&

.AVIATION...
00Z TAF DISCUSSION.

THE COLD FRONT IS MOVING INTO THE STATE. MODELS ARE ALL OVER THE
PLACE AS FOR TIMING...SO WENT WITH A TIMING BASED ON CURRENT
MOVEMENT AND EXPECTATIONS. ADDED IN A 2 HR WINDOW FOR THUNDERSTORMS
AT ALL NORTHERN SITES. AS FOR THE SOUTH WENT JUST VCTS AS THE LINE
MOVES THROUGH SINCE ACTIVITY SHOULD BE ON THE DOWNWARD PROGRESSION.
EXPECT GUSTY NORTHWESTERLY WINDS BEHIND THE FRONT WITH MVFR
CEILINGS. WE WILL NOT SEE CLEARING UNTIL AFTER 18Z...PROBABLY CLOSER
TO 21Z.

16

&&

.PREV DISCUSSION...
/ISSUED 346 PM CST SUN FEB 1 2015/

MUCH OF THE AREA IS CURRENTLY EXPERIENCING A LULL IN THE RAINFALL
AS A BIT OF A DRY SLOT NOSES IN BEHIND AN AREA OF PREFRONTAL RAIN.
ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS LOCATED ALONG THE
COLD FRONT NEAR THE MISSISSIPPI RIVER. THOUGH IT MAY ONLY LAST AN
HOUR OR TWO AT ANY GIVEN LOCATION...THE BAND OF SHOWERS ALONG THE
FRONT SHOULD BE SOLID ENOUGH TO PRODUCE MEASURABLE RAINFALL ACROSS
THE ENTIRE AREA BETWEEN 00-06Z TONIGHT. THE COLD FRONT WILL MOVE
THROUGH QUICKLY OVERNIGHT AS STRONG FORCING APPROACHES WITH A
DYNAMIC UPPER-LEVEL TROUGH AXIS. A FEW SNOW FLURRIES CANNOT BE
RULED OUT AROUND DAYBREAK ACROSS THE NORTH AS 850MB TEMPS DROP TO
AROUND -10C...BUT THIS WILL NOT BE BIG DEAL. TEMPERATURES WILL
STRUGGLE TO RISE MUCH THROUGH THE DAY AS STRONG COLD ADVECTION
CONTINUES INTO THE AFTERNOON. HIGH PRESSURE SHOULD MOVE IN QUICKLY
TO PRODUCE A COLD TUESDAY MORNING WITH LOWS IN THE LOW TO MID 20S.

THERE IS STILL MUCH UNCERTAINTY WITH THE INTERACTION OF SHORTWAVES
IN THE NORTHERN AND SOUTHERN STREAMS ON WEDNESDAY INTO THURSDAY.
MODELS HAVE TRENDED TOWARD A MORE SUPPRESSED SOLUTION TODAY...BUT
THIS COULD EASILY FLIP-FLOP AGAIN BEFORE THE SYSTEM ARRIVES. HAVE
DECIDED TO KEEP LOW POPS FROM WEDNESDAY AFTERNOON INTO THURSDAY.
THERE COULD BE ENOUGH FORCING WITH A NORTHERN STREAM SHORTWAVE TO
PRODUCE LIGHT PRECIPITATION AS A STRONG COLD FRONT PLOWS SOUTHWARD
ON THURSDAY. HAVE LEFT A SLIGHT CHANCE OF A RAIN/SNOW MIX IN THE
NORTHWEST CORNER IN CASE THIS OCCURS. WILL MONITOR FOR CHANGES IN
THE INTERACTION BETWEEN THE NORTHERN AND SOUTHERN STREAM WAVES TO
SEE IF POPS NEED TO BE RAISED OR LOWERED.

DRY AND COOL WEATHER SHOULD TAKE OVER FOR FRIDAY WITH A BIT OF A
WARMING TREND FOR SATURDAY INTO SUNDAY.

87/GRANTHAM

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     36  39  21  50  28 / 100  10   0   0   0
ANNISTON    37  40  24  50  30 / 100  10   0   0   0
BIRMINGHAM  36  41  24  51  32 / 100  10   0   0   0
TUSCALOOSA  36  43  25  53  33 / 100  10   0   0   0
CALERA      37  42  26  52  33 / 100  10   0   0   0
AUBURN      43  44  27  53  34 / 100  10   0   0   0
MONTGOMERY  42  46  27  54  34 / 100  10   0   0   0
TROY        44  46  25  55  33 / 100  10   0   0  10

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$







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