Wildfire in Alabama, March 8, 2010

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
556 AM CST MON MAR 8 2010

.UPDATE...
UPDATED FOR 12Z AVIATION AND FIRE WEATHER DISCUSSIONS.

&&

.AVIATION.../12Z TAFS/
VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS AT BOTH
TERMINALS WITH ONLY HIGH CLOUDS AND LIGHT WINDS EXPECTED. KMSL WILL
SEE A LOWERING CLOUD DECK AFTER 09/09Z BUT THINK ANY -RA WILL
REACH THE TERMINAL AFTER 09/12Z.

&&

.DISCUSSION... /ISSUED 416 AM CST MON MAR 8 2010/

A FAIRLY COMPLEX FCST SITUATION TO EVOLVE STARTING TUES AND LASTING
THROUGH THE END OF THE WEEK. THE MAIN FCST CHALLENGES CENTER AROUND
PRECIP TIMING/AMOUNTS...AND PROBABILITIES FOR EMBEDDED CONVECTION.
RESULTING TEMPERATURES WILL BE DEPENDENT ON PRECIP TIMING...BUT THE
GENERAL PHILOSOPHY WAS TO TREND OVERNIGHT LOWS TOWARDS WARM SIDE OF
GUIDANCE AND DAYTIME HIGHS TOWARD LOW SIDE. AT THIS TIME...DOES NOT
LOOK LIKE A PARTICULARLY HEAVY PRECIP EVENT...ALTHOUGH SOME
LOCATIONS COULD RECEIVE AN INCH OR TWO BEFORE WEEK'S
END...ESPECIALLY IN THE SOUTH. THE AMOUNT OF EMBEDDED CONVECTION
COULD INCREASE PRECIPITATION WITH SOME OF THESE EVENTS...BUT
EXPECTING TSRA ACTIVITY TO BE MAINLY CONFINED TO THE FRONTAL
PASSAGE ON WED NIGHT/THURS MORNING.

SHORT TERM (TODAY THROUGH WEDNESDAY)...
THE FCST CHALLENGE FOR TODAY STILL CENTERS AROUND THE VERY DRY
AIRMASS IN PLACE. GUIDANCE APPEARS TO BE SUFFERING FROM AN
UNCHARACTERISTIC QUICK RETURN OF MOISTURE AGAIN TODAY...AND SO HAVE
UNDERCUT THIS. ALTHOUGH A POOLING OF HIGHER MOISTURE SHOULD TAKE
PLACE TO OUR NORTH TODAY...AM DOUBTFUL THAT WE WILL SEE THE 40S
DEW POINT TEMPS PROGGED BY GRIDDED GUIDANCE FIELDS. GIVEN THE
LIKELIHOOD OF ABUNDANT INSOLATION AND DEEP MIXING...UPSTREAM
SOUNDINGS USED TO COMPARE AGAINST GUIDANCE WOULD SUGGEST PERHAPS
MID AND MAYBE UPPER 30S DEW POINTS AT BEST THIS AFTN. OTHERWISE...
SHOULD BE A FANTASTIC WX DAY...WITH ABUNDANT SUNSHINE AND TEMPS
TOPPING OUT IN THE MID 60S TO NEAR 70.

AN UPPER TROUGH CURRENTLY APPROACHING THE DESERT SW WILL CONTINUE TO
ADVANCE TO THE EAST TODAY. LOW PRESSURE ALREADY DEVELOPING IN THE
FRONT RANGE OF THE ROCKIES...WILL STRENGTHEN RAPIDLY AND ADVANCE
SLOWLY INTO THE CENTRAL PLAINS BY TUES MORNING. WARM/MOIST ADVECTION
ALOFT WILL BEGIN TO OVERRUN MAINLY WRN PORTIONS OF THE FCST AREA BY
12Z. EVEN THE MORE ROBUST GFS SHOWS NEARLY ALL LIFT/MOISTURE
RELEGATED ABOVE 10 KFT...WITH A FAIRLY DRY LOW-LVL LYR. HAVE SCALED
BACK POPS SLIGHTLY...BUT WILL RETAIN CHANCE -RA FOR THE WRNMOST
COUNTIES. IF ANY PRECIP DOES REACH THE SFC...SHOULD BE LIGHT WITH
AMOUNTS LIKELY LESS THAN 0.10".

CONTINUED WARM/MOIST ADVECTION ALOFT WILL GRADUALLY LOWER AS THE
UPPER TROUGH APPROACHES FROM THE WEST ON TUES. A SHORT WAVE WILL
ROUND THE MAIN UPPER TROUGH AS IT BECOMES NEGATIVELY TILTED IN THE
CENTRAL PLAINS...AND CROSS OUR AREA DURING THE AFTN. AT THIS
TIME...IT LOOKS A LITTLE MORE LIKE A GLANCING BLOW JUST TO OUR WEST.
HOWEVER...WITH INCREASING ELEVATED INSTABILITY AND SUFFICIENT
ISENTROPIC LIFT IN THE WARM CONVEYOR BELT...WILL GO WITH LIKELY POPS
IN THE WRN TWO-THIRDS OF THE AREA...AND CHANCE IN THE ERN
TWO-THIRDS. AT THIS POINT...OVERALL QPF DOES NOT LOOK PARTICULARLY
HEAVY GIVEN THE FAIRLY SHALLOW NATURE OF LIFT INVOLVED...AND WILL BE
PARTIALLY DEPENDENT ON ANY POTENTIAL CONVECTION THAT DEVELOPS.

MUCH THE SAME WILL CONTINUE FOR WED AS THE AREA REMAINS STEEPED IN
S-SW FLOW...AND A STRONG TROUGH BEGINS TO EJECT OUT OF THE SW AROUND
THE SOUTHERN FLANK OF THE PARENT TROUGH IN THE MIDWEST. SHRA/TS
CHANCES WILL CONTINUE WITH MAINLY ELEVATED CONVECTION PRESENT.
ALTHOUGH...THE NAM DOES SUGGEST SFC BASED PARCELS MAY BE ALLOWED TO
PLAY A ROLE IN THE CONVECTIVE ENVIRONMENT. WILL HAVE TO WATCH
THIS...ALTHOUGH THIS IS NOT SUPPORTED BY THE GFS ATTM. FCST SHEAR
PROFILES ARE SOMEWHAT STRONG...BUT THINK GUSTY WIND POTENTIAL IS
STILL THE MAIN THREAT WITH ANY TSRA ON WED.

LONG TERM (WED NIGHT THROUGH SUNDAY)...
AS THE SECONDARY UPR TROUGH BECOMES ABSORBED INTO THE PARENT UPR
LOW...A SECONDARY SFC LOW IS PROGGED TO DEVELOP IN THE PLAINS AND
MOVE EWRD TOWARDS THE MID MISS VALLEY. A COLD FRONT TRAILING TO
THE SOUTH OF THE LOW IS EXPECTED TO PUSH ACROSS OUR FCST AREA
EARLY THURS...WITH DECENT AGREEMENT CURRENTLY AMONGST MODEL
SOLUTIONS. AS IN WED...THE NAM IS MORE AGGRESSIVE WITH LOW-LVL
MOISTURE AND RESULTING INSTABILITY. NEVERTHELESS...THINK SHEAR
PROFILES WOULD SUGGEST A LINE OF HVY RAIN WITH EMBEDDED TSRA
MOVING ACROSS THE AREA JUST AHEAD OF THE FRONT. AGAIN...STRONG
WIND GUSTS LOOK TO BE THE PRIMARY THREAT WITH THIS POTENTIAL LINE
OF RA/TSRA.

THE FRONT LOOKS LIKELY TO CLEAR THE AREA TO THE EAST BY LATE
THURS...WITH MILD CAA IN TOW. CURRENT MED RANGE GUIDANCE IS IN GOOD
AGREEMENT IN KEEPING THE DEEP UPR TROUGH OVER THE ERN CONUS AND THE
TN VALLEY THRU LATE IN THE WEEKEND. DISTINCT LOBES OF VORTICITY
SHOULD BRING BOUTS OF MAINLY -SHRA THROUGH THE WEEKEND AMIDST COOL
NW FLOW.

&&

.FIRE WEATHER...

RELATIVE HUMIDITY VALUES WILL FALL BELOW 25 PERCENT FOR MORE THAN
FOUR HOURS ACROSS NORTH CENTRAL AND NORTHEAST ALABAMA THIS
AFTERNOON. THUS...A RED FLAG WARNING IS IN EFFECT FROM 11 AM CST
UNTIL 6 PM CST. THINK THAT MOISTURE WILL INCREASE JUST ENOUGH
ACROSS NORTHWEST ALABAMA THIS AFTERNOON THAT RELATIVE HUMIDITY
VALUES WILL REMAIN ABOVE RED FLAG WARNING CRITERIA.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...RED FLAG WARNING FROM 11 AM THIS MORNING TO 6 PM CST THIS EVENING
     FOR THE FOLLOWING ZONES: CULLMAN...DEKALB...JACKSON...
     LAWRENCE...LIMESTONE...MADISON...MARSHALL...MORGAN.

TN...NONE.
&&

AVIATION/FIRE WEATHER...KNS
DISCUSSION...KDW

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
837 AM CST MON MAR 8 2010

ALZ001>010-016-TNZ076-096-097-082245-
LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN-
MARSHALL-JACKSON-DEKALB-CULLMAN-MOORE-LINCOLN-FRANKLIN TN-
837 AM CST MON MAR 8 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH ALABAMA AND PORTIONS
OF SOUTHERN MIDDLE TENNESSEE.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

RESIDENTS ARE URGED TO EXERCISE CAUTION WITH ANY OUTDOOR BURNING
ACTIVITIES TODAY AS DRY CONDITIONS AND LOW RELATIVE HUMIDITY
VALUES CONTINUE ACROSS NORTHWEST ALABAMA AND SOUTHERN MIDDLE
TENNESSEE.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

SCATTERED THUNDERSTORMS CAN BE EXPECTED WEDNESDAY NIGHT AND
THURSDAY AS A COLD FRONT MOVES THROUGH THE AREA. A FEW OF THESE
STORMS MAY BECOME STRONG AT TIMES WITH GUSTY WINDS AS THE PRIMARY
THREAT.

.SPOTTER CALL TO ACTION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL
IS NOT ANTICIPATED AT THIS TIME.