Flash Flood Warning 34, NWS Huntsville, AL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
652 AM CDT TUE AUG 6 2013

.UPDATE...
FOR 12Z TAFS

&&

.DISCUSSION...
/ISSUED 315 AM CDT TUE AUG 6 2013/
A GRADUAL RETURN TO SOUTHERLY FLOW LATE IN THE EVENING ON MONDAY
HELPED DEWPOINTS TO CLIMB BACK INTO THE UPPER 60S AND LOWER
70S...WHICH HAS LED TO A MILD NIGHT/EARLY MORNING ACROSS THE TN
VALLEY. COMPARED TO LOWS LAST NIGHT IN THE MID TO UPPER
60S...TEMPERATURES HAVE ONLY COOLED INTO THE LOWER 70S TO UPPER 60S.
ELSEWHERE...A COMPLEX OF THUNDERSTORMS THAT TRACKED ACROSS NE ARK IN
THE LATE EVENING MONDAY CONTINUES TO WEAKEN INTO -RA AS IT SLIDES
SSE ACROSS THE MEMPHIS METRO. THE TRAIN OF MCS ACTIVITY CONTINUES
THOUGH WITH ANOTHER COMPLEX TRACKING ACROSS SOUTHERN MO ATTM.

THE COMPLEX OF STORMS CURRENTLY OVER SOUTHERN MISSOURI WILL CONTINUE
TO BE DRIVEN EASTWARD BY A MID LEVEL SHORTWAVE. WHILE THE PREVIOUS
MCS TOOK A DIVE MORE SOUTHWARD DURING THE LATE NIGHT/EARLY MORNING
HOURS TODAY...BULK SHEAR VECTORS AND MODIFICATION OF THE 500MB FLOW
THROUGH TODAY SHOULD DRAW THIS NEXT SYSTEM A BIT MORE SOUTHEASTERLY.
AM THEREFORE ANTICIPATING THAT THE WESTERN PORTION OF THE CWA WILL
HAVE THE BEST CHANCE TO SEE SOME SHOWERS AND THUNDERSTORMS
TODAY...WITH SPREAD OF STORMS EASTWARD ACROSS THE CWA POSSIBLE
DEPENDING ON THE EXPANSION OF THE COLD POOL. THE LOW LEVEL POCKET OF
DRY AIR THAT HELPED REDUCE POP CHCS YESTERDAY ACROSS THE TN VALLEY
HAS ALSO MODIFIED (PER BMX AND OHX SOUNDINGS CAN SEE THAT IT HAS
SHALLOWED AND MOISTENED OVER THE PAST 24HRS)...SO THIS HAS HELPED
INCREASE CONFIDENCE IN MORE POPS THAN WE SAW YESTERDAY.

WIDESPREAD HIGH/MID LEVEL CLOUD COVER AHEAD OF THIS SYSTEM
SHOULD ALSO CONTINUE TO TRACK ACROSS THE CWA TODAY AND KEEP AFTERNOON
MAX TEMPS NEAR THE MID 80S SEEN YESTERDAY (OR A COUPLE OF DEGREES
WARMER DUE TO THE SOUTHERLY FLOW). IN FACT...WITH THE CLOUDS AND
RAIN EXPECTED THROUGH THE END OF THE WEEK...KEPT WITH THE TREND TO
UNDERCUT MOS GUIDANCE IN TERMS OF MAX TEMPS THROUGH THE END OF THE
WORK WEEK.

THE NEXT WEAK SHORTWAVE CURRENTLY OVER THE HIGH PLAINS SHOULD THEN
BRING ANOTHER ROUND OF ENHANCED PRECIP CHCS TO THE CWA ON WEDNESDAY
AFTERNOON. BUT THE BUILDING HIGH PRESSURE OVER THE SOUTHERN PLAINS
SHOULD HELP SHIFT THIS ROUND OF STORMS SLIGHTLY FURTHER EASTWARD AS
IT TRACKS TOWARD THE OHIO/TN VALLEYS. IT SHOULD BE NOTED THAT EACH
ROUND OF STORMS EXPECTED THROUGH THE NEXT WEEK WILL BRING THE
POTENTIAL FOR STRONG WINDS...FREQUENT LIGHTNING AND HEAVY DOWNPOURS
LEADING TO FLASH FLOODING CONCERNS. DEWPOINTS WELL ABOVE 65
DEGREES...CAPE VALUES CLIMBING ABOVE 1500 J/KG EACH AFTERNOON AND
PWATS ARND 1.8 TO 2+ INCHES SUGGEST THE POTENTIAL FOR STRONG TO
SEVERE STORMS.

NO SIGNIFICANT CHANGES HAVE BEEN MADE TO MUCH OF THE REMAINING
FORECAST...WITH A NON-PROGRESSIVE 500MB PATTERN EXPECTED TO DOMINATE
THE CONUS. AS NOTED IN THE AFD YESTERDAY MORNING THE BLOCKING OVER
WESTERN CANADA AND BROAD RIDGING OVER THE SOUTHERN HALF OF THE CONUS
WILL KEEP MUCH OF OUR WEATHER DOMINATED BY SHORTWAVES MOVING ACROSS
THE SHALLOW TROF/NW FLOW. OFF AND ON RAIN CHANCES CAN THEREFORE BE
EXPECTED FOR THE DURATION OF THE FORECAST...WITH TIMING DISCREPANCIES
AMONG VARIOUS MODEL OUTPUT LEADING TO MORE GENERAL CHC POP CHANCES IN
THE FCST. AFTERNOON AND EVENING POP CHANCES WILL STILL BE HIGHER THAN
THE GENERAL FCST THOUGH...WITH WEAK BOUNDARIES MOVING ACROSS THE
REGION AND SOME DIURNAL HEATING TAPPING INTO A MOISTURE RICH
ATMOSPHERE.

THE GOOD NEWS IS THAT ENOUGH MOISTURE IS EXPECTED TO REMAIN ACROSS
THE REGION TO KEEP MOSTLY CLOUDY SKIES THRU MUCH OF THE FORECAST AND
PREVENT A SIGNIFICANT ROUND OF HOT WEATHER. THURSDAY AND FRIDAY MAY
BE THE WARMEST DAYS ACROSS THE CWA AS DEWPOINTS ARE EXPECTED TO CLIMB
INTO THE LOWER/MID 70S AS MOISTURE POOLS AHEAD OF AN APPROACHING
FRONTAL BOUNDARY. THE FRONT WILL BE SLOW MOVING AND LIKELY STALL NEAR
THE TN VALLEY...LEADING TO POP CHCS CONTINUING THROUGH THE WEEKEND.

CCC

&&

.AVIATION...
FOR 12Z TAFS...THE INITIAL BROKEN LINE OF SHRA/TSRA WITH AN
OCCASIONAL TEMPO 4SM TSRA WAS MOVING THROUGH THE HSV TERMINAL AS OF
TAF ISSUANCE. HAVE ADDED IN A TEMPO MVFR VISIBILITY UNTIL 13Z TO
ACCOUNT FOR THIS TSRA ACTIVITY AT HSV. EXPECT ANOTHER AREA OF
SHRA/TSRA ACTIVITY TO MOVE INTO THE TAF SITES BETWEEN THE 18Z AND 19Z
TIME FRAME. THERE MAY BE A TEMPO 4SM/5SM TSRA TEMPO GROUPING WITH THE
NEXT AREA OF SHRA/TSRA EXPECTED TO DEVELOP AND MOVE ACROSS THE AREA.
THE MODELS ARE SIMILAR INVOLVING LESSENING SHRA/TSRA CHANCES AFTER
06Z...BUT WILL ADD IN A TEMPO MVFR FOG AT BOTH HSV AND MSL AFTER 09Z.

TT

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
719 AM CDT TUE AUG 6 2013

ALZ006-061300-
MADISON AL-
719 AM CDT TUE AUG 6 2013

...SIGNIFICANT WEATHER ADVISORY FOR MADISON COUNTY UNTIL 800 AM
CDT...

AT 719 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
AREA OF STRONG THUNDERSTORMS FROM NEAR MADISON TO NEAR REDSTONE
ARSENAL...MOVING SOUTHEAST AT 25 MPH.

VERY HEAVY RAINFALL WITH AMOUNTS RANGING FROM ONE TO CLOSE TO TWO
INCHES WITHIN THE NEXT HOUR...FREQUENT LIGHTNING AND WIND GUSTS TO
AROUND 25 MPH WILL BE ASSOCIATED WITH THE AREA OF STORMS.

LOCATIONS IMPACTED INCLUDE...
HUNTSVILLE...MADISON...MOORES MILL...MERIDIANVILLE AND REDSTONE
ARSENAL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL OCCURRING WITH THESE STORMS MAY LEAD TO MINOR
FLOODING ON ROADS AND IN LOW LYING AREAS. DO NOT DRIVE YOUR VEHICLE
THROUGH FLOODED ROADWAYS.

&&

LAT...LON 3493 8643 3462 8637 3458 8669 3459 8671
      3477 8679 3481 8679 3496 8645
TIME...MOT...LOC 1211Z 300DEG 35KT 3468 8662

TT