Area Forecast Discussion
Issued by NWS Jackson, MS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KJAN 221617 AAA
AFDJAN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
1015 AM CST SAT NOV 22 2014

.UPDATE...LATEST SATELLITE AND UPPER AIR ANALYSIS SHOWED AN INTENSE
SHORT WAVE DEVELOPING INTO THE SOUTHERN PLAINS WITH PLENTY OF JET
ENERGY COMING IN FROM THE ROCKIES...WHICH WILL HELP IT TO BECOME
NEGATIVELY TILTED IN THE SHORT TERM. THE REGION WAS UNDER SOUTHWEST
FLOW AHEAD OF THIS FEATURE. OVER THE ARKLAMISS A POCKET OF DRY AIR
WAS NOTED ACROSS THE REGION FROM THE EAST WITH PWATS FROM 0.6 TO ONE
INCH. PWATS WAS AS LOW AS .50 TO THE EAST OF THE REGION. REGIONAL
SOUNDINGS SHOWED MOSTLY MIDLEVEL MOISTURE ACROSS THE REGION. IT ALSO
SHOWED THAT WE WILL HAVE NO PROBLEMS REACHING INTO THE 60S FOR TODAY.
ALSO SOUTHERLY LOW LEVEL FLOW IS GOING TO INCREASE MOISTURE ACROSS
THE REGION FOR TODAY. AREA RADARS WERE PICKING UP SOME LIGHT
SPRINKLES ACROSS THE NORTHWEST DELTA REGION. LATEST HIRES MODELS
SHOWS THAT THE SPRINKLES WILL MOVE NORTH OF THE REGION BY THIS
AFTERNOON AS THE DRY AIR WILL HAMPER RAIN CHANCES. HOWEVER SOME SPOT
SHOWERS MAY TRY TO DEVELOP ACROSS THE SOUTH BY MID TO LATE AFTERNOON
AHEAD OF THE APPROACHING DEVELOPING STORM SYSTEM. SO WITH THIS IN
MIND HAVE ADJUSTED POPS. HIGHS TODAY IN THE 60S TO AROUND 70 LOOKS
TO BE ON TRACK WITH MORNING READINGS IN THE 50S./17/

&

.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING...BUT
EXPECT QUICKLY DETERIORATING CONDITIONS LATE TONIGHT THROUGH SUNDAY
MORNING AS A SQUALL LINE CROSSES THE REGION. IN THE WAKE OF THE
SQUALL LINE STRONG GUSTY SW WINDS ARE EXPECTED SUNDAY THAT WILL
BECOME LIGHTER BY SUNDAY EVENING. /EC/22/

&&

./PREVIOUS DISCUSSION...448 AM CST SAT NOV 22 2014

...SEVERE WEATHER STILL EXPECTED MAINLY SUNDAY MORNING...

.DISCUSSION...

TODAY THROUGH SUNDAY NIGHT...

THE FORECAST PROCESS HAS RECENTLY BEEN HAMPERED BY UNUSUALLY
DIVERGENT MODEL SOLUTIONS IN THE PAST FEW DAYS...BUT IT SEEMS THEY
ARE BEGINNING TO CONVERGE ON A SOLUTION FOR THE UPCOMING SEVERE WEATHER
SCENARIO EXPECTED TO BEGIN IN ROUGHLY 24 HRS. A STRONG SHORTWAVE
TROUGH IS MOVING STEADILY ACROSS NORTHERN OLD MEXICO AND WILL REACH
THE LOWER MS VALLEY SUNDAY. THE WAVE IS ACCOMPANIED BY AN IMPRESSIVE
TROPOSPHERIC UNDULATION AND PV INTRUSION WHICH WILL QUICKLY DEEPEN
THE LOW PRESSURE SYSTEM AS IT CROSSES THE MS VALLEY REGION. IN THE
ARKLAMISS...UP TO 12MB/6HR SURFACE PRESSURE FALLS ARE ANTICIPATED
SUNDAY MORNING WITH AN INTENSIFYING LOW LEVEL JET > 50KTS SETTING UP
NEAR THE MS RIVER BY 12Z.

WHILE A STABLE BOUNDARY LAYER WILL BE PRESENT INITIALLY...STRONG
MOISTURE TRANSPORT WILL SEND MID 60S DEWPOINTS WELL INTO THE
ARKLAMISS AND HELP TO DESTABILIZE THE AIRMASS SUFFICIENTLY FOR SEVERE
WIND POTENTIAL...PARTICULARLY SE OF THE NATCHEZ TRACE WHERE HIGH RES
GUIDANCE GENERATE A RAPIDLY MOVING QLCS SUNDAY MORNING. 0-3KM SHEAR
VECTORS ORTHOGONAL TO THE LINE OF STORMS CONTINUE TO FAVOR MESOVORTEX
GENERATION AND A THREAT FOR TORNADOES/ENHANCED DOWNBURSTS. HAVE
TAILORED THE HAZARDOUS WEATHER GRAPHIC TO ACCOUNT FOR MORE AGGRESSIVE
BOUNDARY LAYER MOISTURE TRANSPORT AND EXTENDED THE ELEVATED/LIMITED
CATEGORIES FARTHER NORTH...ESPECIALLY OVER ERN MS. THIS IS SUPPORTED
BY SLU CIPS ANALOG GUIDANCE WHICH HAS CONSISTENTLY KEYED ON NE/EC MS
AS AN AREA FOR GREATER SEVERE PROBABILITIES.

THE SYSTEM WILL MOVE QUICKLY THROUGH THE AREA AND BRING A RAPID END
TO THE SEVERE WEATHER POTENTIAL BY AROUND NOON SUNDAY...BUT LINGERING
SHOWER CHANCES ARE FORECAST AHEAD OF THE APPROACHING COLD FRONT FROM
SUNDAY AFTERNOON INTO SUNDAY NIGHT...MAINLY NORTH OF THE I-20
CORRIDOR. HAVE CONTINUED TO MENTION THE POTENTIAL TO MIX DOWN
STRONGER WINDS SUNDAY AFTERNOON THAT COULD REACH WIND ADVISORY
CRITERIA SHOULD TEMPERATURES GET WARM ENOUGH. /EC/

LONG TERM (MONDAY THROUGH NEXT SATURDAY)...BEYOND THIS WEEKEND QUIET
AND RELATIVELY COOL WEATHER CONDITIONS WILL PREVAIL ACROSS THE AREA.

THE PERIOD WILL BEGIN WITH LONGWAVE UPPER TROUGHING OVER THE CENTER
OF THE CONUS...WITH THE ASSOCIATED SURFACE FRONT HAVING ALREADY
DEPARTED THE CWA. WITH THE UPPER TROUGH AXIS STILL LINGERING TO THE
WEST...SOME LOW CLOUDS MAY LINGER INTO THE DAY MONDAY.  MEANWHILE A
SHARP UPPER RIDGE WILL SET UP SHOP ALONG THE PACIFIC COAST OPENING
THE DOORS FOR ANOTHER DOSE OF ARCTIC AIR TO SPILL ACROSS MUCH OF THE
CENTRAL AND EASTERN CONUS. THE BRUNT OF THIS PARTICULAR COLD AIRMASS
WILL REMAIN NORTH OF OUR AREA...BUT IT WILL STILL HELP KEEP
TEMPERATURES ABOUT 5-10 DEGREES BELOW NORMAL FOR MUCH OF THE
UPCOMING HOLIDAY WEEK.

THOUGH CONDITIONS ARE EXPECTED TO REMAIN MOSTLY DRY THROUGH THE
WEEK...THERE ARE A FEW SYSTEMS TO KEEP AN EYE ON WHICH MAY PASS
CLOSE TO THE AREA. ONE SUCH SYSTEM WILL TRACK FROM THE EASTERN GULF
TOWARD THE ATLANTIC COAST LATE TUESDAY INTO WEDNESDAY. NOTABLE RAIN
CHANCES WILL STAY EAST OF OUR AREA WITH THIS SYSTEM. THEN ON
WEDNESDAY A CLIPPER SYSTEM WILL SWING THROUGH THE MIDWEST AS THE
UPPER TROUGH AXIS FINALLY MOVES TO OUR EAST. FOR NOW IT APPEARS ANY
PRECIPITATION WITH THIS SYSTEM WILL REMAIN NORTH OF OUR AREA.

BOTH THANKSGIVING DAY AND BLACK FRIDAY ARE LINING UP TO BE DRY AND
UNSEASONABLY COOL AS A SPRAWLING SURFACE HIGH BUILDS IN OVER THE
MIDDLE PART OF THE COUNTRY. THESE CONDITIONS LOOK TO CONTINUE INTO
NEXT WEEKEND. /DL/

&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON       68  59  74  52 /   3  74  94  17
MERIDIAN      68  57  72  54 /   3  59 100  20
VICKSBURG     70  59  77  50 /  10  83  71  11
HATTIESBURG   68  60  77  57 /  14  75 100  10
NATCHEZ       70  61  78  52 /  21  95  66   9
GREENVILLE    68  57  73  48 /  19  75  75  23
GREENWOOD     68  57  73  49 /   9  61  96  24

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

$$

17/22/EC/DL









USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.