Severe Thunderstorm Warning 39, NWS Huntsville, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
240 PM CDT SUN JUL 4 2004

.DISCUSSION...
REGIONAL RADARS SHOWING A LINE OF STRONG/SEVERE STORMS EXTENDING
FROM MARTIN TN TO CORINTH MS TO NEW ALBANY MS. THIS LINE OF STORMS
IS FEEDING OF MID 70S DWPTS AND SBCAPES BETWEEN 3-4 KJ/KG. WATER
VAPOR IMAGERY AND PROFILER DATA ALSO SHOWS A DISTINCT S/W TROUGH
APPROACHING THE MS RIVER WITH A 40-50 KT MID LEVEL SPEED MAX PUSHING
ACROSS SRN MO. ALTHOUGH THE LOW LEVEL MASS CONVERGENCE IS FAIRLY
WEAK AND THE LINE HAS SHOWN SOME WEAKENING TREND OVER THE LAST 30
MINS...THE FORCING ALONG THE COLD POOL SHOULD BE SUFFICIENT TO
SUSTAIN THE CONVECTIVE LINE FOR A WHILE LONGER.

ON ITS CURRENT COURSE...THE STORMS WILL CLEAR THE REGION BEFORE
SUNSET AND WILL TAPER POPS ACCORDINGLY. WITH CLEARING SKIES...HIGH
DWPTS AND POTENTIAL FOR WET GROUNDS (IF LINE HOLDS TOGETHER)...WILL
MENTION FOG FOR OVERNIGHT. U/L HEIGHTS WILL RISE ACROSS THE SERN
QUARTER OF THE NATION OVER THE NEXT SEVERAL DAYS AND THIS WILL HELP
TO LIMIT PRECIP CHCS TO THE ISOLD CATEGORY. TEMPS WILL ALSO RISE TO
ABOVE CLIMO VALUES FOR THE FIRST TIME IN A WHILE...AND COMBINED WITH
DWPTS IN THE LOWER 70S...WILL PRODUCE HI VALUES NEAR 100 MON/TUE
AFTNS.

LONGER TERM (WEDNESDAY THROUGH SUNDAY)...THE PRIMARY STORM TRACK
WILL RETURN TO THE NORTHERN TIER OF THE CONUS OVER THIS PERIOD AS A
LOW AMPLITUDE RIDGE POSITIONS ITSELF FROM NRN MEXICO TO THE SERN US
COAST. THE GFS CONTINUES TO INDICATE A FROPA IN THE WED/WED NIGHT
TIME FRAME...BUT THE LAST ECMWF AND 12KM ETA STALLS THIS FEATURE
NORTH OF THE TN VLY. GIVEN THE UPPER FLOW PATTERN...AM INCLINED TO
TREND TOWARD THE ECMWF.ETA12 SOLUTION. HOWEVER...THE FAIRLY LOW
AMPLITUDE NATURE OF THE UPPER RIDGE SHOULD HELP KEEP TEMPS FROM
GETTING TOO FAR OUT OF CONTROL LATE THIS WEEK AND WILL TREND TOWARD
THE MID RANGE OF THE ENSEMBLE OUTPUT (I.E. AROUND 90F FOR HIGHS MOST
OF THE WEEK). WILL ALSO CONTINUE WITH THE HIGHEST POPS FOR WED INTO
EARLY THU WITH PASSAGE OF WEAK S/W TROUGH...AND THEN CARRY ISOLD
DIURNAL POPS FOR REMAINDER OF THE WEEK.
&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    73  92  73  92 /  50  20  10  20
SHOALS        73  93  74  91 /  40  20  10  20
CULLMAN       72  93  73  92 /  50  20  10  20
FAYETTEVILLE  72  92  73  91 /  50  20  10  20
FT PAYNE      70  92  71  91 /  50  20  10  20

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...SEVERE THUNDERSTORM WATCH UNTIL 4 PM FOR LAWRENCE...LAUDERDALE
...COLBERT AND FRANKLIN COUNTIES.
TN...NONE.

&&

15

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HUNTSVILLE AL
345 PM CDT SUN JUL 4 2004

ALZ001>010-016-TNZ076-096-097-051000-
COLBERT-CULLMAN-DE KALB-FRANKLIN AL-FRANKLIN TN-JACKSON-LAUDERDALE-
LAWRENCE-LIMESTONE-LINCOLN-MADISON-MARSHALL-MOORE-MORGAN-
345 PM CDT SUN JUL 4 2004

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

.DAY ONE...(THROUGH TONIGHT)...

A COMPLEX OF THUNDERSTORMS MOVING INTO NORTHWEST ALABAMA LATE THIS
AFTERNOON WILL SWEEP ACROSS THE REGION THROUGH EARLY EVENING. AT THIS
TIME...IT APPEARS THAT THE HIGHEST THREAT FOR SEVERE WEATHER WILL BE
ACROSS FAR NORTHERN ALABAMA AND SOUTHERN TENNESSEE...AND THE BEST
TIME FOR SEVERE WEATHER WILL BE BETWEEN 3:30 PM AND 7 PM THIS
EVENING.

THE PRIMARY THREAT WITH THESE STORMS WILL BE STRONG DAMAGING WINDS IN
EXCESS OF 60 MPH. FREQUENT CLOUD TO GROUND LIGHTNING AND VERY HEAVY
RAIN ARE LIKELY WITH THIS COMPLEX AS WELL. COMBINED WITH RECENT
RAINFALL...ISOLATED CASES OF FLASH FLOODING CANNOT BE RULED OUT...
ESPECIALLY ACROSS NORTHWEST ALABAMA.

.DAYS TWO THROUGH SEVEN...(MONDAY THROUGH SATURDAY)...

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

DRY CONDITIONS ARE EXPECTED FOR EARLY NEXT WEEK. AFTERNOON
TEMPERATURES WILL CLIMB INTO THE LOWER 90S BOTH MONDAY AND TUESDAY...
WITH EXPECTED HEAT INDICES EXCEEDING 100 DEGREES.

A MORE TYPICAL SUMMERTIME PATTERN WILL DEVELOP BY THE MIDDLE AND
LATTER PORTIONS OF THE WORK WEEK...WITH ISOLATED AFTERNOON AND EARLY
EVENING THUNDERSTORMS A POSSIBILITY EACH DAY.

.SPOTTER CALL TO ACTION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL MAY
BE REQUIRED LATE THIS AFTERNOON INTO THIS EVENING.

BCC/CBD