Flash Flood Warning 6, NWS Birmingham, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
339 AM CDT FRI JUL 3 2015

.DISCUSSION...

THE OVERALL WEATHER PATTERN HAS CHANGED VERY LITTLE OVER THE PAST
FEW DAYS WITH A LARGE-SCALE TROUGH IN PLACE OVER THE EASTERN HALF
OF THE COUNTRY. TIMING OF SHORTWAVES ROTATING AROUND THE BASE OF
THE TROUGH HAS BEEN PROBLEMATIC TO SAY THE LEAST. CONFIDENCE IS A
BIT HIGHER IN THIS FORECAST PACKAGE THOUGH...AS MODELS GENERALLY
AGREE IN THE EVOLUTION OF THE PATTERN THROUGH SUNDAY. A POSITIVELY
TILTED TROUGH AXIS STRETCHING FROM INDIANA TO THE SOUTHERN PLAINS
WILL APPROACH OUR AREA OVER THE NEXT 36 TO 48 HOURS. SEVERAL
EMBEDDED IMPULSES ARE EXPECTED TO EJECT EASTWARD BEFORE THE MAIN
TROUGH AXIS MOVES INTO THE AREA ON SUNDAY. LOW-LEVEL FLOW
CIRCULATING AROUND A SUBTROPICAL RIDGE OVER THE EASTERN GULF WILL
CONTINUE TO PROVIDE AN EXCELLENT SOURCE OF MOISTURE DURING THIS
TIME FRAME. THE AFOREMENTIONED SETUP SHOULD LEAD TO A CORRIDOR OF
PERSISTENT SHOWER AND THUNDERSTORM ACTIVITY THAT SAGS SLOWLY
SOUTHWARD AS THE TROUGH AXIS APPROACHES. WE ARE ALREADY SEEING
EVIDENCE OF THIS IN THE FORM OF A BAND OF SHOWERS AND STORMS
CURRENTLY EXTENDING WEST TO EAST FOR SEVERAL HUNDRED MILES AND
FLIRTING WITH THE NORTHERN FRINGE OF THE CWA. AS A RESULT...POPS
HAVE BEEN RAISED FOR TODAY AND TONIGHT FOR AREAS MAINLY NEAR AND
NORTH OF I-20. PWAT VALUES NEAR 2 INCHES AND A SYNOPTIC PATTERN
SUPPORTIVE OF TRAINING ECHOES COULD LEAD TO SEVERAL INCHES OF
RAINFALL IN A SHORT PERIOD OF TIME. WILL INTRODUCE A POTENTIAL FOR
ISOLATED FLASH FLOODING INTO THE HWO THROUGH TONIGHT...AND THIS
MAY NEED TO BE EXTENDED INTO SATURDAY OR SATURDAY NIGHT AS WELL.

THE TROUGH WILL BE SLOW TO MOVE THROUGH AND HIGH POPS ARE
WARRANTED FOR SATURDAY AND SUNDAY AS WELL. THE MAIN ZONE OF
RAINFALL IS EXPECTED TO CONTINUE TO SAG SLOWLY SOUTHWARD ACROSS
THE CENTRAL AND POSSIBLY INTO THE SOUTHERN PART OF THE AREA BY
SUNDAY. SOMEWHAT LOWER RAIN CHANCES ARE EXPECTED BY MONDAY AND
TUESDAY THE TROUGH FINALLY MOVES EASTWARD AND WEAKENS.

87/GRANTHAM

&&

.AVIATION...
06Z TAF DISCUSSION.

LOOKING FOR PERIODS OF SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN HALF OF THE AREA. A BOUNDARY SAGGING SOUTHWARD WILL
INCREASE THE CHANCE FOR SHOWERS LATER TONIGHT TO AROUND DAYBREAK.
THESE SHOULD DIMINISH BEFORE A MORE ACTIVE AFTERNOON PATTERN
DEVELOPS ACROSS THE NORTH WITH LIMITED POTENTIAL IN THE SOUTH NEAR
MGM AND TOI. WINDS SOUTHWEST AT 5 TO 15 KTS.

88

&&

.FIRE WEATHER...

HIGH HUMIDITY VALUES AND ABOVE NORMAL RAIN CHANCES WILL CONTINUE
FOR THE NEXT FEW DAYS. THERE ARE NO FIRE WEATHER CONCERNS.

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     86  69  82  69  83 /  80  80  70  50  60
ANNISTON    87  70  84  69  83 /  60  80  70  60  60
BIRMINGHAM  88  71  84  70  84 /  60  80  70  60  60
TUSCALOOSA  91  71  84  71  87 /  60  80  70  60  60
CALERA      88  70  84  70  84 /  60  70  60  60  60
AUBURN      89  71  84  70  83 /  30  40  60  60  60
MONTGOMERY  94  73  89  72  88 /  30  40  50  50  60
TROY        93  72  87  71  87 /  20  20  50  50  50

&&

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

87/88

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
416 AM CDT FRI JUL 3 2015

ALZ011>015-017>050-041230-
MARION-LAMAR-FAYETTE-WINSTON-WALKER-BLOUNT-ETOWAH-CALHOUN-CHEROKEE-
CLEBURNE-PICKENS-TUSCALOOSA-JEFFERSON-SHELBY-ST. CLAIR-TALLADEGA-
CLAY-RANDOLPH-SUMTER-GREENE-HALE-PERRY-BIBB-CHILTON-COOSA-TALLAPOOSA-
CHAMBERS-MARENGO-DALLAS-AUTAUGA-LOWNDES-ELMORE-MONTGOMERY-MACON-
BULLOCK-LEE-RUSSELL-PIKE-BARBOUR-
416 AM CDT FRI JUL 3 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE
NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM.

.DAY ONE...TODAY AND TONIGHT.

A SLOW MOVING BOUNDARY WILL SLIDE SOUTHWARD THROUGH TONIGHT
ACROSS THE NORTHERN PORTIONS OF CENTRAL ALABAMA. SHOWERS AND
STORMS WILL MOVE EASTWARD ALONG AND BEHIND THAT BOUNDARY.
STORMS WILL TRAIN OVER THE SAME AREAS AND WILL RESULT IN AT
LEAST LOCALIZED FLOODING AND POSSIBLE FLASH FLOODING.

AREAS NORTH OF A VERNON TO ASHVILLE MAY SEE THE FLOODING THIS
MORNING. AREAS NORTH OF TUSCALOOSA TO TALLADEGA MAY SEE THE
FLOODING THIS AFTERNOON AND TONIGHT. AREAS NORTH OF A LINE FROM
DEMOPOLIS TO ALEXANDER CITY COULD SEE HEAVY RAIN AND LOCALIZED
FLOODING TONIGHT AND INTO THE OVERNIGHT HOURS.

IN ADDITION TO THE FLOODING...CAN NOT RULE OUT AN ISOLATED SEVERE
THUNDERSTORM WITH DAMAGING WINDS THE MAIN CONCERN ALONG AND AHEAD
OF THE BOUNDARY. THE MAIN TIMEFRAME OF CONCERN HERE WOULD THIS
AFTERNOON THROUGH 9 PM.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT MAY BE
NEEDED THROUGH TONIGHT.