FXUS64 KBMX 302321
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
515 PM CST MON NOV 30 2009
.UPDATE...FOR AVIATION DISCUSSION.
&&
.DISCUSSION...
TONIGHT THROUGH WEDNESDAY NIGHT...A COLD FRONT WAS ON ITS WAY
OUT OF CENTRAL ALABAMA THIS AFTERNOON. THE FRONT SHOULD EXIT
SOUTHEAST AREAS WITHIN THE NEXT FEW HOURS. STILL SOME LIGHT RAIN
SHOWERS IN THE VICINITY OF THE FRONT...BUT THE MORE CONSIDERABLE
RAIN HAS PUSHED SOUTH OF THE AREA. AT THIS TIME...WILL NOT MENTION
ANY RAIN FOR THE OVERNIGHT HOURS. CLOUDS WILL DECREASE FROM NORTH
TO SOUTH OVERNIGHT WITH TEMPERATURES DROPPING INTO THE 30S
AREAWIDE.
THE COLD FRONT STALLS NEAR THE GULF COAST AND WILL QUICKLY RETURN
NORTHWARD AS A WARM FRONT TUESDAY NIGHT AS SOUTHERN STREAM ENERGY
KICKS OUT OF THE SOUTHWEST. THE NAM REMAINS THE SLOWEST AND FARTHEST
WEST OF THE MODELS WHILE THE GFS IS THE QUICKEST AND FARTHEST EAST.
WILL LEAN TOWARD THE ECMWF AS IT HAS SHOWN GOOD RUN TO RUN
CONSISTENCY IN TIMING AND PLACEMENT. THE DYNAMIC UPPER SYSTEM WILL
ALLOW CYCLOGENESIS TO OCCUR NEAR THE MOUTH OF THE MISSISSIPPI TUESDAY
EVENING. THE LOW WILL QUICKLY MOVE NORTHWARD AND INTO THE TENNESSEE
VALLEY BY WEDNESDAY EVENING.
THE WIND FIELDS ASSOCIATED WITH THIS SYSTEM ARE TREMENDOUS. THERE
WILL BE SOME TYPE OF ADVISORY NEEDED AS WIND GUSTS UP TO 35 MPH
WILL BE POSSIBLE...IF NOT HIGHER...AREAWIDE TUESDAY NIGHT INTO
WEDNESDAY. INSTABILITY APPEARS TO BE LACKING SOMEWHAT. SURFACE
BASED LI'S ONLY MANAGE -1 OR SO FAR SOUTH. CAPES ARE ALSO LIMITED
WITH VALUES OF 500 OF LESS. WIND SHEAR IS VERY HIGH AND ANY
VERTICAL DEVELOPMENT MAY NOT REMAIN ORGANIZED...IT MAY TIP OVER.
THEREFORE...SEVERE POTENTIAL REMAINS FAIRLY LOW. BUT WITH ANY
DEEPENING LOW PRESSURE SYSTEM COMING OUT OF THE GULF IN A HIGH
SHEAR/LOW CAPE ENVIRONMENT...WE NEED TO WATCH THE PARAMETERS CLOSELY
FOR BRIEF SPIN UP TORNADOES AND STRAIGHT LINE WINDS. THE SMALL SEVERE
THREAT APPEARS LIMITED TO AREAS GENERALLY ALONG AND SOUTH OF I-85...
BUT WILL BE DE ON THE TRACK OF THE SURFACE LOW. RAINFALL MAY
BECOME EXCESSIVE...WITH RAIN AMOUNTS OF 2 TO 4 INCHES EXPECTED IN A
12 HOUR PERIOD. THE FORCING WITH THIS SYSTEM IS VERY HIGH AND
PRECIPITABLE WATER VALUES APPROACH 1.5 INCHES OR HIGHER ACROSS MUCH
OF THE AREA SOUTH OF I-20. A FEW SHOWERS ARE POSSIBLE WEDNESDAY
NIGHT AS THE STORM SYSTEM EXITS NORTHEASTWARD AND DRIER AIR BUILDS
IN FROM THE WEST LATE.
THURSDAY THROUGH MONDAY...THE GFS AND ECMWF HAVE ENOUGH
SIMILARITIES THAT THE CONFIDENCE ON A COLD STRETCH GOES UP. DOME
OF HIGH PRESSURE BUILDS OVER THE HEART OF DIXIE AND THICKNESS
VALUES PLUMMET. IT WILL BE QUITE COLD THURSDAY THROUGH SATURDAY
WITH HIGHS ONLY IN THE 40S NORTH. BY FRIDAY AND SATURDAY
MORNINGS...HAVE LOWS IN THE MID 20S IN MANY LOCATIONS. THIS
APPEARS TO BE THE COLDEST AIRMASS OF THE SEASON SO FAR. MODELS
HINT AT MORE OF A ZONAL FLOW BY PERIODS END WITH A GRADUAL
MODERATION.
&&
.AVIATION...00Z TAF DISCUSSION.
CEILINGS 1500 TO 2500 FEET WILL DISSIPATE FROM NORTHWEST TO
SOUTHEAST ACROSS THE AREA THROUGH 04Z. AFTER 04Z EXPECT CLEAR SKIES
ACROSS THE AREA. NORTH WINDS AROUND 10 MPH WILL DIMINISH AFTER 04Z
WITH EAST WINDS 5 TO 10 MPH EXPECTED AFTER 15Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
GADSDEN 33 55 45 58 40 / 0 0 90 100 50
ANNISTON 34 58 49 61 40 / 0 10 100 100 40
BIRMINGHAM 35 60 53 58 40 / 0 10 90 100 40
TUSCALOOSA 35 58 53 59 39 / 0 10 90 90 40
CALERA 37 57 53 60 40 / 0 10 100 90 40
AUBURN 37 62 49 61 42 / 10 10 100 100 30
MONTGOMERY 37 60 54 64 43 / 0 20 100 100 30
TROY 38 60 56 64 43 / 10 20 100 100 30
&&
.BMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
KSL
