Area Forecast Discussion
Issued by NWS Jackson, MS

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000
FXUS64 KJAN 272116
AFDJAN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
316 PM CST SAT DEC 27 2014

.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...WV IMAGERY THIS
AFTERNOON SHOWING MID/UPPER LEVEL SYSTEM CONTINUING TO DIG
SOUTH...NOW ENTERING NW MEXICO. TO THE EAST...MID/UPPER LEVEL
ANTICYCLONE REMAINS NEARLY STATIONARY OVER THE CARRIBEAN. RESULTING
FLOW IN BETWEEN HAS BECOME INCREASINGLY SSW ALLOWING THE MOISTURE
RICH AIR (PWATS NEAR 2 INCHES) OVER THE NW GULF OF MEXICO TO BE
TAPPED.

ALREADY...ELEVATED CONVECTIVE CLUSTERS MOVING OVER SE MS HAVE
PRODUCED SUBSTANTIAL RAINS WITH SPORADIC STREET FLOODING BEING
REPORTED. LATEST HRRR DATA IS INDICATING CONVECTION WILL FILL BACK
IN ALONG THE MID 60 DEWPOINT AXIS...CURRENTLY BISECTING LA...AS IT
MOVES INTO WESTERN MS EARLY THIS EVENING. BELIEVE THE AXIS OF
HEAVIEST RAINS WILL SET UP ALONG THE EASTERN FLANK OF THE DEWPOINT
GRADIENT WHICH WILL OCCUR COINCIDE WITH THE AXIS OF HIGHEST PWAT
COMING IN OFF THE NORTHERN GULF OF MEXICO. THE NAM...HRRR...GFS...
AND ECMWF ALL HAVE SIMILAR QPF SOLUTIONS.

WHILE PWAT VALUES AS HIGH AS WE ARE SEEING IS ANOMALOUS ENOUGH (+3
STANDARD DEVIATIONS)...EVEN MORE AMAZING IS THE FACT THAT THE
MAJORITY OF THE MOISTURE SEEMS TO BE LOCATED BELOW 700 MB WHEN
LOOKING AT AREA SOUNDINGS FROM THIS MORNING AND AFTERNOON. ABOVE 700
MB PROFILES ARE QUITE DRY. THIS HAS ALLOWED FOR CONVECTIVE
DESTABILIZATION AS MOISTURE CONTINUES TO STREAM IN AND IS MOST
LIKELY RESPONSIBLE FOR THE ELEVATED STORMS WITH HAIL THAT WE ARE
CURRENTLY SEEING. BELIEVE THIS WILL CONTINUE TO BE A PROBLEM TONIGHT
UNTIL THE COLUMN CAN BECOME SUBSTANTIALLY SATURATED. WILL CONTINUE
TO OUTLOOK OUR LIMITED SEVERE THREAT...BUT MOVE IT A LITTLE FURTHER
NORTH BASED ON CURRENT TRENDS. THERE STILL APPEARS TO BE A LIMITED
TORNADO THREAT OVER THE SOUTHERN FRINGES OF THE FORECAST AREA WHERE
MORE IN THE WAY OF SURFACE BASED CONVECTION CAN GET GOING.

FRONTAL BOUNDARY MOVING THROUGH AFTER MIDNIGHT WILL ALLOW RAINFALL
TO WANE SOMEWHAT. HOWEVER...DO EXPECT IT TO BREAK OUT AGAIN SUNDAY
AS WHATS LEFT OF PHASING MID LEVEL WAVE WORKS ITS WAY THROUGH.
RAINFALL WILL TAPER OFF RAPIDLY AFTER MIDNIGHT SUNDAY NIGHT./26/

.LONG TERM...MONDAY THROUGH SATURDAY...SURFACE HIGH PRESSURE RIDGING
WILL BUILD IN ON MONDAY ACROSS THE ARKLAMISS WITH COOLER HIGHS
RANGING FROM THE LOW TO MID 50S. LITTLE CHANGE IS EXPECTED TUESDAY...
BUT COLDER AIR WILL MOVE IN TUESDAY NIGHT AS COLD HIGH PRESSURE NOSES
INTO THE REGION. NEW YEARS EVE DAY TEMPERATURES WILL ONLY CLIMB INTO
THE 40S AND LOWER 50S. NEW YEARS EVE WILL BE COLD WITH LOWS WEDNESDAY
NIGHT FALLING INTO THE UPPER 20S/LOW 30S.

THE PATTERN OVER THE AREA WILL BEGIN TO CHANGE ON THURSDAY AS THE
SURFACE HIGH SHIFTS TO THE EAST AND AN UPPER TROUGH DEEPENS OVER THE
SOUTHERN PLANES. MOISTURE WILL INCREASE OVER THE AREA THURSDAY NIGHT
INTO FRIDAY WITH SHOWERS ON THE INCREASE FRIDAY AFTERNOON. THE
GLOBAL MODELS DIVERGE ON THEIR SOLUTIONS FRIDAY NIGHT INTO SATURDAY
WITH THE GFS TAKING THE SURFACE LOW NORTH AND THE ECMWF FURTHER
SOUTH. EITHER WAY SHOWERS AND STORMS WILL BE ON THE INCREASE AS WE
GET INTO THE WEEKEND WITH ANOTHER ROUND OF HEAVY RAINFALL AND
POSSIBLY SOME SEVERE STORMS./15/26/

&&

.AVIATION...LOW MVFR TO IFR CIGS NOW COVER AREA. TSRA WITH VERY
HEAVY RAIN MOVING THROUGH PINE BELT REGION HAS BEEN LOWERING VSBYS
TO LESS THAN 1SM AT TIMES AT KHBG THIS AFTERNOON. MORE OF THIS SORT
OF ACTIVITY WILL MOVE INTO KHBG AREA AFTER 22Z...AS WELL AS POTENTIALLY
IMPACT KGLH/KGWO/KHKS TOWARD 00Z. OVERALL...IFR CIGS WITH OCCASIONAL IFR
VSBYS/LIFR CIGS IN SHRA/TSRA WILL BE THE RULE TONIGHT AT ALL TAF
SITES. RAINFALL WILL TAPER OFF SOMEWHAT FROM WEST TO EAST 09Z TO 15Z
AS COLD FRONT SLOWLY MOVES EAST ACROSS REGION. WINDS WILL SHIFT TO THE
NW/N AFTER FROPA...AND BECOME GUSTY IN THE DELTA REGION AS STRONG HIGH
PRESSURE BUILDS INTO THE REGION. IFR/LOW MVFR CIGS WILL PERSIST IN THE
WAKE OF THE FRONT THROUGH AT LEAST 18Z.        /AEG/


&&


.PRELIMINARY POINT TEMPS/POPS...
JACKSON       52  54  42  53 / 100  97  94   8
MERIDIAN      58  62  45  56 / 100  94  95  14
VICKSBURG     48  50  40  52 / 100  98  89   6
HATTIESBURG   62  67  48  59 / 100  63  82   7
NATCHEZ       50  52  41  53 / 100  95  87   5
GREENVILLE    43  46  37  50 / 100  89  75   7
GREENWOOD     46  48  39  51 / 100  96  85   9

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLASH FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR MSZ026>033-
     036>039-042>066-072>074.

LA...FLASH FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR LAZ026.

AR...NONE.
&&

$$







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