000
FXUS64 KBMX 182010
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
310 PM CDT TUE JUN 18 2013


.SHORT TERM...TONIGHT THROUGH FRIDAY.

A SURFACE FRONT HAS PUSHED INTO NORTHWEST ALABAMA THIS AFTERNOON.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS HAVE DEVELOP IN
THE WARM AND UNSTABLE AIR MASS SOUTH THE FRONT. THE FRONTAL
BOUNDARY SHOULD BE NEAR THE I-20 CORRIDOR BY SUNSET...SO ANY RAIN
AREAS AFTER SUNSET SHOULD BE CONFINED TO AREAS SOUTH OF I-20. WITH
DRIER AIR MOVING IN ALOFT TONIGHT AND WEAK COOL AIR ADVECTION AT THE
LOW LEVELS...THERE WILL LIKELY A ZONE A STRATUS AND FOG ALONG THE
I-20 CORRIDOR FORMING AFTER MIDNIGHT. WITH THE SURFACE FRONT
STALLING OUT BETWEEN MONTGOMERY AND TROY ON WEDNESDAY...THERE WILL
A CHANCE OF THUNDERSTORMS ACROSS THE SOUTHEAST COUNTIES. NORTHERLY
WINDS ON WEDNESDAY WILL BRING LOWER HUMIDITIES TO MOST OF THE
AREA...BUT WITH MOST FRONTS THIS TIME OF YEAR...THERE WILL NOT BE
ANY INTRUSION OF COOLER AIR...AND HIGHS ON WEDNESDAY WILL BE
ACTUAL SLIGHTLY ABOVE AVERAGE.

THE MODELS CONTINUE TO SHOW AN EXPANSION OF THE TEXAS UPPER RIDGE
TO THE NORTHEAST BY FRIDAY. THE SOUTHEAST STATES REMAIN UNDER A
WEAK UPPER TROF...SO SMALL RAIN CHANCES WILL CONTINUE ACROSS THE
AREA THURSDAY AND FRIDAY...MAINLY EAST OF I-65.

58/ROSE

.LONG TERM...SATURDAY THROUGH TUESDAY.

VERY LITTLE CHANGE IN THE UPPER AIR PATTERN DURING THIS PERIOD
WITH ABOVE AVERAGE PRECIPITABLE WATER VALUES AND WEAK FLOW ALOFT.
THIS PATTERN WILL ALLOW FOR SCATTERED DIURNAL CONVECTION EACH DAY.

58/ROSE


&&

.AVIATION...
18Z TAF DISCUSSION.

EXPECT NUMEROUS SHOWERS/TSTORMS TO CONTINUE THRU THE AFTN/EVNG
AHEAD OF A COLD FRONT. SOME STORMS COULD PRODUCE GUSTY
WINDS AND BRIEF HEAVY RAINFALL...AND OF COURSE LIGHTNING WILL BE
PRESENT. WENT WITH A GENERAL SHRA VCTS FOR ALL SITES IN THE
NEAR TERM...BUT WILL AMEND TO ACCOUNT FOR MORE DIRECT IMPACTS FROM
TSRA. ACTIVITY SHOULD COME TO AN END ACROSS THE NORTH THIS
EVENING AS THE FRONT PUSHES SOUTHWARD. THE SOUTHERN TERMINALS
COULD SEE SOME SCT SHOWERS AND ISO TS INTO THE NIGHT BEFORE THE
FRONT PASSES THRU. WINDS WILL SHIFT FROM SW TO W JUST AHEAD OF THE
FRONT AND THEN TO THE NW BEHIND THE FRONT.

OTHER THAN TIMING OF TSRA TODAY THE OTHER FORECAST CHALLENGE WILL
BE CIG/VIS OVERNIGHT. MODELS DISAGREE ON WHETHER THERE WILL BE
STRATUS OR FOG OR NEITHER. BASED ON WHAT OCCURRED BEHIND THE FRONT
ACROSS THE MID MISSISSIPPI VALLEY LAST NIGHT...WILL LEAN TOWARD
THE DEVELOPMENT OF A LOW STRATUS DECK (IFR) ACROSS THE NORTH
BEHIND THE FRONT LATER TONIGHT. NOT EXTREMELY CONFIDENT BUT FEEL
THAT THIS IS THE MOST LIKELY OUTCOME ATTM. IF NO LOW CLOUDS
DEVELOP AND SKIES REMAIN MOSTLY CLEAR...THEN WITH LIGHT/CALM WINDS
FOG WILL BE LIKELY. COULD ALSO SEE SOME MVFR CIGS IN THE
SOUTH...BUT THERE SHOULD BE ENOUGH CLOUD COVER THERE TO PREVENT
ANY WIDESPREAD FOG CONCERNS. WILL MONITOR TRENDS CLOSELY FOR
POSSIBLE UPDATES/CHANGES TO THE OVERNIGHT FORECAST.

19


&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     64  89  63  89  66 /  10  10  10  10  10
ANNISTON    67  89  65  89  68 /  20  10  10  20  10
BIRMINGHAM  67  89  69  91  70 /  20  10  10  10  10
TUSCALOOSA  68  91  65  92  69 /  20  10  10  10  10
CALERA      68  88  68  90  68 /  30  10  10  20  10
AUBURN      70  86  68  89  69 /  40  20  10  20  20
MONTGOMERY  72  88  68  92  70 /  50  20  10  30  20
TROY        71  87  68  90  69 /  40  30  10  30  20

&&

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

&&

$$