376
FXUS64 KHUN 151712 AAC
AFDHUN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1212 PM CDT MON JUL 15 2019
UPDATE
FOR 18Z TAFS.
NEAR TERM
(REST OF TODAY)
ISSUED AT 855 AM CDT MON JUL 15 2019
REMNANTS OF TROPICAL STORM BARRY WILL CONTINUE TO IMPACT THE REGION
TODAY, WITH PERIODS OF MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS
EXPECTED -- ESPECIALLY ACROSS NORTHWEST AND NORTH CENTRAL ALABAMA. A
CURRENT GLANCE AT SATELLITE RADAR SHOWS BANDS OF DEEP CONVECTION
PUSHING NNE FROM EAST CENTRAL MISSISSIPPI TOWARD THE WESTERN ALABAMA
BORDER. THIS TREND WILL CONTINUE OVER THE NEXT 3-6 HOURS, AND WOULD
EXPECT A STEADY UPTICK IN COVERAGE AS THIS OCCURS. WITH VERY HIGH
PWAT VALUES (CLOSE TO 2" ACROSS THIS AREA), WOULD EXPECT HEAVY
RAINFALL AND POSSIBLE LOCALIZED FLOODING ISSUES TO OCCUR, ESPECIALLY
IN AREAS WEST OF THE I-65 CORRIDOR WHEN 2-3" OF RAINFALL HAS OCCURRED
SINCE 12Z SUNDAY. IT IS CONCEIVABLE THAT RAINFALL RATES IN THE
DEEPEST CONVECTION OF 1-2"/HR COULD CAUSE SOME CONCENTRATED AREAS OF
FLASH FLOODING -- ESPECIALLY WHERE TRAINING OCCURS.
AS IS THE CASE WITH ANY LANDFALLING TROPICAL SYSTEM, WE'LL HAVE THE
POTENTIAL FOR SOME STRONG TO SEVERE THUNDERSTORMS, ESPECIALLY IF
THINGS CAN DESTABILIZE A LITTLE MORE LATE THIS MORNING INTO THIS
AFTERNOON. THE CURRENT AREA OF CONCERN IS A BAND STRONG THUNDERSTORMS
CURRENTLY MOVING NNE FROM AROUND THE GWX RADAR SITE INTO FAR
NORTHWEST ALABAMA BY 15-18Z. WITH SOME DENSE MORNING CIRRUS, WE'VE
REMAINED CAPPED ACROSS MUCH OF THE AREA -- BUT WOULD EXPECT SOME
BREAKS TO DEVELOP BY THE AFTERNOON. THIS WOULD ALLOW FOR AT LEAST
SOME MODEST DESTABILIZATION (CAPE ~ 1000 J/KG). THIS COMBINED WITH A
HIGHER LOW-LEVEL HELICITY VALUES COULD CREATE SOME MARGINALLY SEVERE
LOW-TOPPED STORMS CAPABLE OF LOCALIZED DAMAGING WIND GUSTS AND A
WEAK, BRIEF TORNADO. THE MOST FAVORED AREAS OF DEEP CONVECTION WILL
BE LOCATIONS ALONG AND WEST OF THE INTERSTATE 65 CORRIDOR, ESPECIALLY
ACROSS FAR NORTHWEST ALABAMA.
OTHERWISE, EXPECT PERIOD OF RAIN WITH A MOSTLY CLOUDY SKY. THESE
CONDITIONS WILL LIMIT HEATING AND KEEP TEMPERATURES WELL BELOW
NORMAL, WITH HIGHS RANGING FROM THE UPPER 70S/LOWER 80S (WEST) TO THE
MID 80S (EAST).
SHORT TERM
(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 AM CDT MON JUL 15 2019
THE REMNANTS OF EX-TROPICAL SYSTEM BARRY BY THE EARLY EVENING SHOULD
BE MOVING NORTHWARD OVER THE OZARKS OF AR/MO, THEN BE NEAR THE SAINT
LOUIS AREA TOWARDS TUESDAY AFTERNOON. DEEP TROPICAL MOISTURE
ASSOCIATED WITH THIS SYSTEM WILL BRING MORE CLOUDS AND CHANCES OF
SHOWERS THROUGH THE MID WEEK. HIGHER RAIN CHANCES WILL GENERALLY BE
OVER AREAS WEST OF I-65 THROUGH TUESDAY EVENING. THE EX-TROPICAL
SYSTEM TOWARDS THE MID WEEK WILL BEGIN HEADING TO THE NE AND THE
SOUTHERN GREAT LAKES. AN AXIS OF MOISTURE MOVING SOUTH OF IT WILL
BRING GREATER RAIN CHANCES TO OUR NORTHERN AREAS FOR THE MIDWEEK. AS
SUCH, KEPT LIKELY SHOWER/THUNDERSTORM CHANCES FOR WEDNESDAY
AFTERNOON.
OVERALL SHEAR WILL DECREASE DURING THE TUE-WED TIME FRAME, WHICH WILL
REDUCE A SEVERE WEATHER THREAT. BUT HIGH AMOUNTS OF PRECIPITABLE
WATER WILL RESULT IN LOCALLY HEAVY DOWNPOURS, GUSTY WINDS AND
FREQUENT LIGHTNING. BETWEEN AND BEFORE SHOWERS, HIGH TEMPERATURES FOR
TUE/WED SHOULD RANGE IN THE UPPER 80S TO AROUND 90 (TRENDING A BIT
COOLER ON WED GIVEN HIGHER RAIN CHANCES). HEAT INDEX VALUES WILL
RISE INTO THE MID TO UPPER 90S EACH DAY.
LONG TERM
(THURSDAY NIGHT THROUGH SUNDAY)
ISSUED AT 328 AM CDT MON JUL 15 2019
THE MAIN STORY IN THE LONG TERM WILL BE THE RETURN OF THE EXCESSIVE
HEAT AS ZONAL FLOW TAKES OVER AND HIGH PRESSURE SETTLES IN OVER THE
VALLEY TOWARD THE WEEKEND. HIGH TEMPERATURES WILL RETURN TO THE 90S
ON THURSDAY, AND WILL REACH WELL INTO THE MIDDLE 90S BY THE WEEKEND.
THIS, COUPLED WITH DEW POINTS IN THE LOW TO MIDDLE 70S WILL BRING
HEAT INDICES WELL ABOVE 100 FROM THURSDAY THROUGH THE END OF THE
WEEKEND. AT THIS POINT, IT CERTAINLY LOOKS LIKE WE COULD REACH HEAT
ADVISORY CRITERIA DURING THIS PERIOD IN AREAS AROUND THE VALLEY,
WITH HEAT INDICES TOPPING OUT IN THE 105-108F RANGE. THIS WILL
CERTAINLY BEAR WATCHING IN THE COMING DAYS. OVERNIGHT LOWS WILL
GENERALLY RANGE FROM THE LOW TO MIDDLE 70S, SO NO REAL RELIEF FROM
THE HEAT IS EVIDENT AT THIS POINT.
THUNDERSTORM CHANCES WILL GENERALLY DECREASE THROUGH THE SECOND HALF
OF THE WORK WEEK, WITH ONLY SLIGHT CHANCES FOR SHOWERS AND STORMS
DURING PEAK DIURNAL HEATING HOURS. NO ORGANIZED SYSTEMS ARE EXPECTED
THROUGH THE WEEKEND.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1211 PM CDT MON JUL 15 2019
VFR CONDITIONS WILL BE THE PREDOMINANT FLIGHT CATEGORY AT EACH
TERMINAL THROUGH THE PERIOD. A BAND OF SCATTERED SHRA WILL CONTINUE TO
MOVE ACROSS NORTH ALABAMA THIS AFTERNOON, PERHAPS PRODUCING
LOCALIZED MVFR CONDITIONS BETWEEN 1518/1521. A BRIEF PERIOD OF VCTS
MAY ALSO BE POSSIBLE AT KMSL LATE THIS AFTERNOON. LATE TONIGHT INTO
EARLY TUESDAY MORNING, LOW CLOUDS WILL FORM AT BOTH TERMINALS, WITH
BKN CEILINGS AROUND 2.5 KFT. THESE MVFR CONDITIONS MAY LAST THROUGH
MOST OF THE REMAINDER OF THE PERIOD.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...AMP.24
SHORT TERM...RSB
LONG TERM...25
AVIATION...AMP.24
FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page