620
FXUS64 KJAN 171757
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1157 AM CST FRI JAN 17 2025
..NEW AVIATION
MESOSCALE UPDATE
ISSUED AT 1036 AM CST FRI JAN 17 2025
DRY AND SUNNY CONDITIONS ARE ALLOWING TEMPERATURES TO WARM ABOVE
SEASONAL NORMS TODAY WITH A PLEASANT DAY IN STORE. WEAK RETURNS
ARE ALREADY SHOWING ON RADAR OVER NORTHERN AND CENTRAL LOUISIANA,
INDICATING MOISTENING IS ALREADY UNDERWAY UPON APPROACH OF A
SOUTHERN STREAM SHORTWAVE. THIS WILL BRING AN ONSET OF RAIN
SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM LATER THIS AFTERNOON
AND EVENING. MOST OF THE DAY WILL REMAIN DRY HOWEVER, AS DEWPOINT
DEPRESSIONS REMAIN 10-20 DEGREES./SAS/
DISCUSSION
ISSUED AT 442 AM CST FRI JAN 17 2025
TODAY THROUGH TOMORROW...
WE'LL STAY DRY TODAY WITH AFTERNOON HIGHS IN THE LOWER 60S F AFTER
BEING AROUND THE FREEZING MARK FOR MOST AREAS AS WE START THE DAY
THIS MORNING. PATCHY FROST AND SOME SHALLOW PATCHY FOG WILL GIVE WAY
TO PLENTIFUL SUN AND AN AFTERNOON THAT MIGHT BY SOME ACCOUNTS FEEL
PLEASANT. CERTAINLY A WARMER REPRIEVE WHEN CONSIDERING THE RECENT
AND INCOMING COLD PERIODS. TONIGHT WILL FEATURE INCREASING CLOUDS
AND SHOWERS WITH ISOLATED THUNDERSTORMS MOVING GENERALLY FROM
WEST TO EAST. WITH CLOUDS AND ENHANCED WARM ADVECTION, LOWS
CONTINUE TO WARM AHEAD OF THE FRONT THAT WILL CLEAR THE AREA BY
LATE DAY SATURDAY. LOWS TONIGHT LIKELY WILL BE 15 DEGREES F OR SO
WARMER THAN WE ARE SEEING THIS MORNING, RANGING FROM THE UPPER 40S
F TO LOWER 50S F. SATURDAY WARMS QUICKLY ON BREEZY WARM, SOUTH
WINDS AS SHOWERS AND ISOLATED THUNDERSTORMS BEGIN TO MOVE EAST OF
THE AREA INTO THE AFTERNOON WITH A SHARP COLD FRONT SCOURING
REMAINING MOISTURE. TEMPERATURES WILL RISE QUICKLY INTO THE 60S F
AND PERHAPS LOWER 70S F BEFORE ABRUPTLY TURNING COLDER:
TEMPERATURES IN THE EARLY EVENING WILL LIKELY ALREADY HAVE FALLEN
INTO THE LOWER 40S F AROUND HIGHWAY 82 AND INTO THE 50S F FOR
POINTS NEAR AND SOUTH OF I-20, A DROP OF 4 TO 5 DEGREES F AN HOUR
FOR 2-3 HOURS IMMEDIATELY BEHIND THE FRONT. /86/
SATURDAY NIGHT THROUGH MID-WEEK...
FRIGID TEMPERATURES AND SNOW CHANCES ARE IN STORE! BE SURE THAT YOU
AND YOUR LOVED ONES HAVE A WARM PLACE TO STAY NEXT WEEK.
AN ARCTIC AIR MASS IS PROGGED TO MOVE INTO THE AREA SATURDAY NIGHT
BRINGING FRIGID TEMPERATURES AND SNOW CHANCES TO THE AREA.
TEMPERATURES WILL BE FAR BELOW SEASONAL NORMS, WITH LOWS IN THE
TEENS AND HIGHS IN THE MID 30S. MODEL GUIDANCE CONTINUES TO SUGGEST
WINTRY WEATHER, PREDOMINATELY IN THE FORM OF SNOW, WILL BE POSSIBLE
FOR MUCH OF THE AREA WITH AREAS ALONG THE THE HIGHWAY 84 CORRIDOR
CREEPING INTO "PROBABLE" CHANCES (>50% LIKELIHOOD) FOR ACCUMULATING
SNOWFALL. AS IS OFTEN THE CASE, DETERMINING SNOW
AMOUNTS/ACCUMULATION IS CHALLENGING WITH MODEL GUIDANCE HAVING HIGH
VARIANCE. FOR EXAMPLE, SNOW AMOUNTS ACROSS BOTH GFS/ECMWF ARE
SUBSTANTIALLY LOWER THAN THE CANADIAN GEM MODEL WITH THE SUITE OF
TYPICALLY RELIABLE GUIDANCE RANGING FROM ALMOST NOTHING TO SEVERAL
INCHES. OF INCREASING CONFIDENCE THOUGH, IS THAT THE SOUTHERNMOST
QUADRANT OF THE FORECAST AREA IS EXPECTED TO BE WHERE OUR LARGEST
ACCUMULATIONS ARE LIKELY TO OCCUR FOR THIS EVENT, DUE TO THE
INCREASED GULF FLOW/MOISTURE IN PROXIMITY TO THE DISTURBANCE MOVING
ACROSS THE GULF OF MEXICO. UNUSUALLY, THIS EVENT IS LIKELY GOING TO
BE CONTINGENT ON ADEQUATE MOISTURE FOR PRECIPITATION AS OPPOSED TO
SUPPORTIVE THERMAL PROFILES AS A CONSENSUS OF RELIABLE GUIDANCE HAS
LARGELY CONVERGED ON FORECASTS VERY SUPPORTIVE OF FROZEN
PRECIPITATION, WERE IT TO FALL.
BEHIND THIS FRONT, AS MENTIONED ABOVE, FRIGID COLD DRY WINDIER
CONDITIONS WILL BUILD INTO THE AREA WHICH WILL CAUSE TEMPERATURES TO
PLUMMET. WHILE AMBIENT HIGH TEMPERATURES WILL HOVER IN THE MID 30S
THE WINDIER INFLUENCE WILL CAUSE WIND CHILLS TO RANGE IN THE MID 20S
AND WIND CHILL LOWS TO DROP INTO THE SINGLE DIGITS AT TIMES. IT IS
FOR THAT REASON THAT WE HAVE CONTINUED TO ADVERTISE A DANGEROUS COLD
HAZARD GRAPHIC. IT SHOULD BE NOTED THAT GUIDANCE HAS TRENDED COLDER
EACH RUN AND TEMPERATURES MAY BE EVEN COLDER IN FUTURE FORECAST
PRODUCTS, IF THE UPSTREAM COLD AIR SAMPLING DEMONSTRATES THAT A
COLDER FORECAST IS IN ORDER.
THURSDAY ONWARDS...
A BRIEF RETURN TO ONSHORE FLOW WILL CAUSE A BIT OF A REBOUND TO OUR
MOISTURE PROFILE THIS REBOUNDING OF MOISTURE AHEAD OF AN APPROACHING
LOW WILL ALLOW FOR A CHANCE OF PRECIPITATION ACROSS THE CWA. TIMING
AND EXACT INTENSITY OF THE MOISTURE PROFILE WILL BE KEY TO
FORECASTING THIS UPCOMING SYSTEM. AS WAS THE CASE WITH THE PREVIOUS
EVENT, SOME MODEL MEMBERS HAVE PRECIPITATION STARTING WHEN
TEMPERATURES ARE AT OR ABOVE FREEZING, FOR THE SAME PERIOD; OTHER
MEMBERS HAVE US BELOW FREEZING BUT INSUFFICIENT MOISTURE FOR
PRECIPITATION. AT THIS TIME WE FEEL ITS BEST TO ERR TOWARDS STARTING
THE PRECIPITATION LATER ON IN THE DAY WHEN TEMPERATURES HAVE
REBOUNDED ABOVE FREEZING. THIS WILL HAVE THE EFFECT OF FORECASTING A
COLD RAINY DAY. BE MINDFUL OF UPDATES FOR THIS TIME FRAME AS WE GAIN
MORE CONFIDENCE ON THE AFOREMENTIONED FACTORS AND THE SUBSEQUENT
PRECIPITATION TYPE AND INTENSITY. /OAJ/
AVIATION
(18Z TAFS)
ISSUED AT 1153 AM CST FRI JAN 17 2025
VFR CONDITIONS WILL PREVAIL THROUGH THE DAY TODAY. CLOUDS WILL
INCREASE THIS AFTERNOON AND EVENING AND RAIN WILL ONSET THIS
EVENING. TIMING FOR MOST OF THE RAIN WILL BE BETWEEN 6PM AND
MIDNIGHT. WINDS WILL ALSO BEGIN TO GUST AROUND 15 TO 20MPH AHEAD
OF AN APPROACHING COLD FRONT OUT OF THE SOUTH. IN THE WAKE OF THE
RAIN, LOW STRATUS WILL SETTLE IN TOMORROW MORNING, WITH CEILINGS
DROPPING TO MVFR THROUGH THE REST OF THE TAF PERIOD./SAS/
PRELIMINARY POINT TEMPS/POPS
JACKSON 51 67 29 39 / 70 20 0 0
MERIDIAN 49 69 31 42 / 90 20 0 0
VICKSBURG 51 66 29 40 / 60 0 0 0
HATTIESBURG 52 73 36 45 / 80 20 0 0
NATCHEZ 53 66 31 41 / 50 0 0 0
GREENVILLE 47 59 28 35 / 30 10 0 0
GREENWOOD 49 62 27 37 / 70 20 0 0
JAN WATCHES/WARNINGS/ADVISORIES
MS...NONE.
LA...NONE.
AR...NONE.
LP/OAJ/SAS20
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