FXUS64 KBMX 291231
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
630 AM CST SUN NOV 29 2009
.UPDATE...AVIATION DISCUSSION.
&&
.DISCUSSION...
SCATTERED TO BROKEN MID LEVEL CLOUDS WILL SPREAD ACROSS THE SOUTHEAST
STATES TODAY AHEAD OF ADVANCING NORTHERN STREAM SHORT WAVE TROF.
NORTHERN STREAM SHORT WAVE TROF WILL PUSH A COLD FRONT INTO NW
ALABAMA LATER TONIGHT. LOOKING AT UPSTREAM UPPER AIR SOUNDINGS...
PRECIPITABLE WATER (PW) VALUES ARE MEAGER WITH MOST LOCATIONS
REPORTING BETWEEN 0.50-0.75 INCHES. PW VALUES ARE FORECAST TO RISE
TO NEAR 1.5 INCHES MONDAY MORNING ACROSS NORTH ALABAMA...WHICH
WILL HELP KEEP SHOWERS GOING ALONG ADVANCING SURFACE FRONT. THE
LINE OF SHOWERS SHOULD WEAKEN AS IT MOVES SOUTHWARD ON MONDAY AS
MAIN UPPER LEVEL LIFT SHIFTS EASTWARD...AND KEPT ONLY LIKELY RAIN
CHANCES DURING THE MORNING HOURS. THE RAIN SHOULD BE GONE BY
SUNSET MONDAY AS MUCH DRIER MID LEVEL AIR MASS MOVES IN ON NORTH
SIDE OF SHORT WAVE TROF.
THE DRY AIR MASS WILL RESULT IN MOSTLY CLEAR SKIES MONDAY NIGHT
AND TUESDAY MORNING. CUT-OFF LOW OVER THE SOUTHWEST STATES WILL
LIFT EASTWARD AND BRING CLOUDS BACK INTO CENTRAL ALABAMA TUESDAY
AFTERNOON. MOISTURE WILL RAPIDLY INCREASE ACROSS AREA TUESDAY
NIGHT AND WEDNESDAY AS STRONG FORCING ALOFT SPREADS EASTWARD
AHEAD OF ADVANCING UPPER LOW. THE DEEPENING UPPER LOW WILL PRODUCE
A SURFACE LOW OVER THE NORTHWEST GULF OF MEXICO TUESDAY NIGHT.
THIS WILL ESTABLISH A STRONG LOW LEVEL BAROCLINIC ZONE ALONG THE
COAST WHERE STRONG CONVECTION WILL DEVELOP. MODELS ARE HAVING A
HARD TIME WITH TRACK OF SURFACE LOW WITH THE NAM AND ECMWF MODELS
SHOWING LOW MOVING NORTHWARD ALONG THE MISSISSIPPI RIVER WHILE THE
GFS TAKES THE LOW ON A MUCH MORE EASTWARD PATH TOWARDS NORTHWEST
FLORIDA. THE MORE NORTHERN TRACK WOULD INCREASE THREAT OF STORMS
ACROSS SOUTHERN COUNTIES. FORECAST WILL STAY WITH THE MORE
CONSISTENT GFS MODEL RUNS. CONFIDENCE IS TO LOW A THIS TIME TO
INCLUDE ANY THREAT OF STRONG STORMS IN OUTLOOKS. SURFACE WINDS
WILL INCREASE TO 15-20 MPH ON WEDNESDAY AS SURFACE LOW APPROACHES
SOUTH ALABAMA.
TUESDAY NIGHT THRU WEDNESDAY NIGHT WILL BE A VERY WET PERIOD
ACROSS CENTRAL ALABAMA DUE TO CLOSE PROXIMITY OF SURFACE LOW ON
WEDNESDAY AND STRONG UPPER LOW WHICH WILL MOVE ACROSS NORTH
ALABAMA WEDNESDAY NIGHT. UPPER LOW SHOULD BE EAST OF ALABAMA BY
SUNRISE THURSDAY. DRIER AIR AND SUBSIDENCE ON BACK SIDE OF TROF
WILL BRING CLEARING SKIES AND RAIN FREE CONDITIONS THURSDAY THRU
SATURDAY. DEEPENING AND EXITING SURFACE LOW WILL PULL DOWN A MUCH
COLDER AIR MASS AND HIGHS ON THURSDAY MAY NOT GET OUT OF THE 40S
ACROSS NORTH ALABAMA.
58/ROSE
&&
.AVIATION...12Z TAF DISCUSSION.
LIGHT RAIN SHOWERS BEGAN MOVING IN MUCH EARLIER THAN ANTICIPATED.
HOWEVER...THESE SHOWERS SHOULD HAVE LITTLE TO NO AVIATION IMPACTS
(VISIBILITIES AND CEILINGS) AT LEAST THROUGH THE NEXT 24 HOURS.
STILL EXPECTING FOR THE MAIN BULK OF RAIN TO MOVE IN
TOMORROW...MAINLY AFTER 06Z TONIGHT.
10/ARM
&&
.BMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
