National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS64 KHUN 072157
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
357 PM CST FRI MAR 7 2014

.DISCUSSION...
A RELATIVELY BENIGN AND PERHAPS WELCOME PATTERN IS
STILL FORECAST FOR THE TN VALLEY FOR MOST OF THE NEXT SEVEN DAYS.
THE LARGE SCALE PATTERN WILL FEATURE A GENERAL ZONAL UPR FLOW ACROSS
THE SOUTHERN TIER OF THE CONUS...WHILE A SERIES OF STRONG UPR SHORT
WAVES WILL CONTINUE TO MAINTAIN NW FLOW ACROSS MUCH OF THE NORTHERN
TIER.  CHANCES FOR PRECIP FOR THE TN VALLEY STILL REMAIN FOR
SUNDAY...WITH BETTER CHANCES MAINLY FOR TUESDAY NIGHT AND WEDNESDAY.
OTHERWISE...AN OVERALL WARMER PATTERN IS IN STORE FOR THE REGION
THROUGH WEDNESDAY...BEFORE SEASONABLY COOL CONDITIONS RETURN ON
THURSDAY. CHANGES TO THE ONGOING FCST WERE RELATIVELY MINOR...WITH
SLIGHTLY GREATER CONFIDENCE IN RAIN ON SUNDAY AND AGAIN ON TUESDAY
NIGHT LEADING TO INCREASED POPS FOR THOSE PERIODS. AS USUAL...MORE
DETAILS CAN BE FOUND BELOW.

TEMPS HAVE RISEN MAINLY INTO THE 60S THIS AFTERNOON UNDER ABUNDANT
SUNSHINE AND AS WINDS SHIFT TO THE WEST BEHIND A DEPARTING TROUGH.
ALTHOUGH A FEW GUSTS HAVE OCCURRED TODAY...WINDS HAVE BEEN
RELATIVELY LIGHT FOR THE MOST PART...AND WILL CONTINUE TO WEAKEN AS
A SFC RIDGE CROSSES THE AREA TONIGHT. A NARROW RIBBON OF MOSTLY
TRANSLUCENT CIRRUS WILL CROSS THE AREA TONIGHT...BUT SHOULD NOT A
SIGNIFICANT IMPACT ON TEMP DECREASES. TEMPS ARE LIKELY TO FALL INTO
THE 30S AT MOST LOCATIONS...AND PATCHY FOG IS ALSO EXPECTED MAINLY
IN LOW-LYING AND VALLEY LOCATIONS.

WARMER CONDITIONS ARE ANTICIPATED FOR SATURDAY UNDER GOOD INSOLATION
AMIDST DEEP SW-W FLOW. TEMPS ARE GENERALLY ABOVE MOS VALUES WITH
AFTERNOON VALUES MOSTLY IN THE MID 60S TO LOW 70S.

CLOUDS WILL GRADUALLY BE ON THE INCREASE SAT NIGHT AS ISENTROPIC ASCENT
AND MID/UPR MOISTURE ADVECTION DEVELOP AHEAD OF AN APPROACHING SHORT
WAVE TROUGH. LIFT IN THE MOIST-BEARING LAYER SHOULD BE SUFFICIENT TO
PRODUCE SOME LIGHT PRECIP IN OUR NW COUNTIES AROUND 06-09Z.
ALTHOUGH...OVERALL FORCING IS WEAK AND LIFT IS NOT SUBSTANTIAL...THUS
ONLY LIGHT RAIN IS EXPECTED AT THIS TIME WITH THE UPR TROUGH AS IT
MOVES ACROSS THE REGION. THE LIKELIEST PERIOD FOR MEASURABLE RAIN
(ALBEIT LIGHT) SHOULD OCCUR DURING THE 12Z-18Z PERIOD...WHEN A
CONSENSUS OF GUIDANCE INDICATES THE FLOW WILL BE MOST ORTHOGONAL TO
ISOBARS ON THE THETA SFC. STILL...THIS LOOKS LIKE A LIGHT RAIN EVENT
AT BEST...AND HAVE ONLY RAISED POPS TO 30 PCT FOR SUNDAY. MOS APPEARS
A BIT OPTIMISTIC FOR TEMPS ON SUNDAY...BUT VALUES WERE NOT ADJUSTED
THAT MUCH FOR NOW. IF CLOUD COVER REMAINS SUFFICIENTLY THICK FOR MOST
OF THE DAY...CURRENT VALUES IN THE LOW/MID 60S ARE LIKELY TO
DECREASE.

A WARMING TREND WILL ENSUE ON MONDAY AND CONTINUE INTO TUESDAY AS A
TROUGH DIGS INTO THE WEST...A CLOSED LOW MOVES ACROSS TX...AND UPR
FLOW HERE IN THE TN VALLEY TILTS SLIGHTLY FROM WNW TO WSW. IN THE
LOWER LEVELS HOWEVER...SW FLOW AROUND THE WESTERN FLANK OF HIGH
PRESSURE WILL ENVELOP THE REGION IN WAA. TEMPS MAY REACH THE LOW TO
MID 70S FOR MANY LOCATIONS BY TUESDAY AFTERNOON.

MOISTURE ADVECTION AND ISENTROPIC ASCENT WILL AGAIN TAKE PLACE BY
LATE TUESDAY AS THE SOUTHERN PLAINS SYSTEM LIKELY TAKES A PATH ALONG
THE GULF COASTAL PLAIN. ANOTHER MUCH MORE SIGNIFICANT SERIES OF
SHORT WAVES EMBEDDED WITHIN THE NH WESTERLIES WILL CARVE OUT A
TROUGH IN THE CENTRAL PLAINS BY LATE TUESDAY INTO WED AND GIVE RISE
TO CYCLOGENESIS IN THE SOUTHERN/CENTRAL PLAINS. THE TWO SYSTEMS MAY
NOT ENTIRELY PHASE...BUT THE RESULT WILL BE TO KEEP RAIN CHANCES IN
FOR THE AREA FROM TUESDAY NIGHT THROUGH WED NIGHT. THIS FORECAST
PACKAGE WILL TREND TOWARDS THE 12Z ECMWF SOLUTION...WHICH FAVORS A
MORE PROGRESSIVE PATTERN WITH THE SHORT WAVE TROUGH DIGGING INTO THE
WESTERN CONUS TUES-WED. THE GFS SOLUTION TENDS TO CLOSE THE LOW OFF
IN THE SW CONUS...WHICH WILL NOT ENTIRELY UNREALISTIC LOOKING...HAS
LIMITED SUPPORT FROM ENSEMBLE GUIDANCE. IT IS POSSIBLE THAT A
PORTION OF THE MID-LVL COLD POOL (VORT MAX) WILL BECOME CLOSED
OFF...BUT GIVEN THE EXPECTED HEIGHT OF THE NW RIDGE AND DOWNSTREAM
TROUGHING...A MORE PROGRESSIVE OVERALL PATTERN APPEARS LIKELY AT
THIS TIME. WILL KEEP ONLY RAIN CHANCES IN THE FORECAST FOR THE
PERIOD AND WILL NOT ADD LIGHTNING/THUNDER...AS INSTABILITY APPEARS
QUITE LIMITED AND MOSTLY RELEGATED TO ELEVATIONS BELOW THE MIXED
PHASE LAYER ON TUESDAY NIGHT AND WED.

KDW

&&

.AVIATION...
/ISSUED 1159 AM CST FRI MAR 7 2014/
FOR 18Z TAFS...VFR CONDITIONS ARE EXPECTED AT KHSV/KMSL UNTIL FOG
DEVELOPMENT AROUND 09Z. VIS MAY LOWER INTO UPPER MVFR CATEGORY FOR A
FEW HOURS. VARIABLE NORTHERLY WINDS TODAY WILL BECOME SOUTHEASTERLY
BY SATURDAY MORNING BUT VFR CONDITIONS ARE EXPECTED THROUGH THE REST
OF THE TAF PERIOD.

JMS

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    40  71  46  66 /   0  10  10  30
SHOALS        40  71  45  65 /   0  10  20  30
VINEMONT      38  67  47  64 /   0  10  10  30
FAYETTEVILLE  35  66  45  62 /   0  10  20  30
ALBERTVILLE   38  68  46  66 /   0  10  10  30
FORT PAYNE    37  67  47  66 /   0  10  10  30

&&

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

$$

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