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000
FXUS64 KBMX 160910
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
410 AM CDT SUN JUN 16 2013

.SYNOPSIS...
A WEAK WARM FRONT MOVES NORTHWARD TODAY AND GRADUALLY DISSIPATES.
BOUNDARY LAYER WINDS WILL SHIFT FROM SOUTHEAST TOWARD A SOUTH
SOUTHWEST DIRECTION ALLOWING SURFACE DEW POINTS TO INCREASE. AN
OUTFLOW BOUNDARY FROM PREVIOUS CONVECTION WILL APPROACH FROM THE
NORTHWEST TODAY BUT THE MAIN FRONT WILL REMAIN NORTH OF THE AREA.
MOISTURE AHEAD OF THE OUTFLOW WILL INCREASE THE MEAN MOISTURE FOR
NORTHERN COUNTIES. A SHORT WAVE TROUGH ALSO TRAVERSES THE AREA THIS
AFTERNOON. THEREFORE...THERE IS A CHANCE OF CONVECTION TODAY MAINLY
DURING THE MAXIMUM HEATING OF THE DAY.

IT APPEARS THAT THE ADVERTISED UNSETTLED WEATHER WILL REMAIN A GOOD
BET MONDAY THROUGH WEDNESDAY. A FEW BOUTS OF SHOWERS AND
THUNDERSTORMS WILL OCCUR ASSOCIATED WITH SEVERAL UPPER LEVEL WAVES
AND AN APPROACHING COLD FRONT. THE FRONT SHOULD SLOWLY SAG
SOUTHWARD BY WEDNESDAY AFTERNOON...LIMITING CONVECTION SOUTHWARD BY
THEN.

A SHIFT TO MORE CLIMATOLOGICAL AND DIURNAL CONVECTION THURSDAY
THROUGH SUNDAY.

&&

.SHORT TERM...
TODAY THROUGH WEDNESDAY...

INCREASED SHOWER AND THUNDERSTORM PROBABILITIES TODAY INTO THE
CHANCE RANGE (25-30). SHORT WAVE ENERGY DEPICTED NEAR EASTERN TEXAS
THIS MORNING WILL MOVE EASTWARD AND PROVIDE SOME INCREASE IN WINDS
ALOFT AND UPWARD MOTION/LIFT. BULK SHEAR VALUES CLIMB BUT ONLY INTO
THE 25-35 KT RANGE. THIS WILL COMBINE WITH INCREASING MEAN MOISTURE
LEVELS AS WARM FRONT/SOUTHERLY FLOW INCREASES. EVEN WITH PRECIP
WATER VALUES JUMPING BACK TO 1.70+...K INDICES DO NOT JUMP OVER 30.
THEREFORE...THINK THE COVERAGE WILL BE LIMITED. CAN NOT RULE OUT A
STRONG STORM OR TWO DUE TO THE INSTABILITY...SLIGHT INCREASE IN
WINDS ALOFT...MDPI/WINDEX VALUES...AND DRY AIR IN THE MID LEVELS...
WITH GUSTY WINDS THE THREAT. OF NOTE HERE...THE NAM IS A BIT MORE
AMBITIOUS WITH INSTABILITY AND MOISTURE THIS AFTERNOON.

A FEW MORE SHORT WAVE TROUGHS EMBEDDED WITHIN THE UPPER LEVEL FLOW
WILL TRAVERSE THE REGION AS A TROUGH APPROACHES. THIS SETS
THE STAGE FOR A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS MONDAY INTO
EARLY WEDNESDAY. THE MODELS HAVE BEEN IN FAIR AGREEMENT WITH THE
THERMODYNAMIC ENVIRONMENT BUT HAVE HAD SOME TIMING ISSUES. THE GFS
IS THE FASTEST WITH BRINGING A TEMPORARY DRYING INTO CENTRAL
ALABAMA...FOLLOWED BY THE NAM AND CMC...WITH THE SLOWEST BEING THE
ECMWF/HPC. WILL LEAN TOWARD THE MIDDLE GROUND OF THE NAM/CMC WHICH
IS CLOSER TO THE GFS THAN THE ECMWF. THE ECMWF KEEPS THE FRONT AS A
CONVECTIVE FOCUS THROUGH THURSDAY BEFORE A SHORT BREAK. THE GFS HAS
BEEN TOO FAST WITH SYSTEMS LATELY WHILE THE NAM HAS BEEN SLOW...SO
THE ECMWF SEEMS WAY TOO SLOW IN THIS FORECAST PERIOD. THERE WILL
ALSO BE MESOSCALE EFFECTS THAT WILL PLAY A ROLE IN THE OVERALL
EVOLUTION OF THE EFFECTIVE FOCUSING MECHANISMS.

.LONG TERM...
THURSDAY THROUGH SUNDAY...

IT APPEARS THAT THE VARIOUS MODEL OUTPUT IS IN A BIT MORE AGREEMENT
TODAY WITH THE OVERALL SYNOPTIC PATTERN...BUT DIFFERENCES STILL
APPEAR IN THE SENSIBLE WEATHER DEPARTMENT. MEAN RELATIVE HUMIDITY
VALUES VARY BETWEEN MODEL AND DAY TO DAY. ADDITIONALLY...THE
POSITION OF ANY LEFTOVER SURFACE BOUNDARIES WILL PLAY A ROLE IN
FOCUSING CONVECTION. IT ALSO APPEARS WE WILL BE IN THE PATH OF ANY
MCS THAT CAN DEVELOP UPSTREAM AS WE WILL REMAIN UNDER A WEAKNESS
IN THE UPPER RIDGE THROUGH THE PERIOD.

WITH ALL THIS BEING SAID...WILL LEAN TOWARD A MORE
CLIMATOLOGICAL/DIURNALLY ENHANCED POP FORECAST AT THIS TIME. IF AND
WHEN ANY PARTICULAR FEATURE CAN BE PIN POINTED WITH ANY ACCURACY...
SOME ADJUSTMENTS IN THE POP TIMING MAY BECOME NECESSARY.

75

&&

.AVIATION...
06Z TAF DISCUSSION.

VFR CONDITIONS CURRENTLY ACROSS THE TERMINALS AND EXPECT THESE
CONDITIONS WILL CONTINUE OVER THE NEXT 24 HRS. MODELS ARE COMING
IN LESS IMPRESSIVE WITH THE LOW LEVEL AND HAVE DECIDED TO REMOVE
ANY MENTION OF MVFR CEILINGS. THERE COULD BE A BRIEF PERIOD OF
MVFR CONDITIONS AROUND SUNRISE BUT NOT ENOUGH CONFIDENCE EXISTS TO
INCLUDE IN THE TAFS. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
TOMORROW AFTERNOON BUT WILL BE TOO SCATTERED TO INCLUDE IN THE
TAFS AT THIS TIME.

05/MA

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     89  68  86  71  84 /  30  40  60  70  70
ANNISTON    88  71  87  72  85 /  30  30  60  50  70
BIRMINGHAM  88  73  88  74  85 /  30  30  60  50  70
TUSCALOOSA  92  73  90  74  86 /  30  30  60  50  70
CALERA      89  72  87  73  85 /  30  30  60  50  70
AUBURN      88  71  86  72  84 /  30  20  50  40  50
MONTGOMERY  92  74  90  74  88 /  30  20  50  40  50
TROY        91  70  90  74  90 /  30  20  40  30  50

&&

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

&&

$$

75/75/05