000
FXUS64 KJAN 250823
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
323 AM CDT SAT MAY 25 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT...THE PRIMARY CONCERNS WILL
BE THE ISSUE OF ISOLATED CONVECTION IN THE WEST FOR TONIGHT AND
SUNDAY. THIS FOLLOWED BY THE RISK OF A FEW RECORD LOWS IN THE EAST
FOR THIS MORNING AS WELL AS COOL NIGHTS DURING THE PERIOD THEN
FOLLOWED BY LOW POPS AND TEMPS.
LATEST SATELLITE IMAGERY SHOWED THE REGION UNDER NORTHWEST FLOW
ALOFT...WHILE THE ARKLAMISS REGION WAS BEING FLANKED BY AN UPPER
RIDGE OVER THE ARKLATEX AND AN UPPER TROUGH OFF THE EASTERN SEABOARD.
THERE WAS ALSO AN UPPER TROUGH OVER THE SOUTHERN PLAINS WITH SOME
DECENT MOISTURE CONVERGENCE...WHICH WAS APPROACHING THE REGION. ON
THE SURFACE A WEAK STATIONARY FRONT WAS NOTED FROM SOUTHERN
LOUISIANA THROUGH THE CENTRAL PLAINS. COOL CANADIAN HIGH PRESSURE
WAS CENTERED OVER THE MID TO UPPER MS VALLEY. TEMPERATURES WERE WELL
BELOW NORMAL IN THE 50S TO LOWER 60S.
FOR TODAY AND TONIGHT...THERE WILL BE A RISK OF BEAT SOME RECORD
LOWS IN THE EAST THIS MORNING AS TEMPERATURES DIP INTO THE 40S. ON
CLIMATE STATS HATTIESBURG RECORD LOW OF 52 IN 1983 AND MERIDIANS LOW
OF 47 IN 1979. OTHERWISE EXPECT MOSTLY HIGH CLOUDS COMING FROM THE
CONVECTION FROM THE SHORTWAVE IN THE SOUTHERN PLAINS. HIGHS TODAY WILL
BE FROM THE LOWER TO MIDDLE 80S. WENT CLOSE TO MAV GUIDANCE. FOR TONIGHT
THE SOUTHERN PLAINS SHORTWAVE WILL WEAKEN AS IT ADVANCES SLOWLY TOWARD
THE ARKLAMISS REGION. THIS WILL BRING A LOW CHANCE OF CONVECTION FOR
AREAS ACROSS THE MS RIVER. THE GFS WAS THE ONLY MODEL BRINGS A RISK OF
SOME ISOLATED CONVECTION ACROSS SE ARKANSAS AND NORTHEAST LOUISIANA
AS THE WEAK FRONT LIFTS SLOWLY TO THE NORTH. THE LOCAL WRF...NAM AND
SREF MODELS WERE LESS OPTIMISTIC WITH THE RAIN CHANCES ACROSS THE MS
RIVER. THE MAV POPS LOOKED A LITTLE HIGH SO WENT WITH THE LOWER TEEN
POPS FROM GMOS GUIDANCE. THE SPC WRF BRINGS SOME RAIN OVER SOUTHERN
ARKANSAS AND NORTH LOUISIANA FOR TONIGHT. THE NATIONAL WRF MODELS
SHOWED SOME SHOWERS ACROSS THE SAME AREA. LOWS FOR TONIGHT WILL BE
FROM THE UPPER 40S TO THE LOWER 60S. WENT CLOSE TO MAV GUIDANCE.
FOR SUNDAY AND SUNDAY NIGHT...THE WEAKEN UPPER SHORTWAVE WILL MOVE
OVER THE REGION. THE GFS CONTINUED TO BRING VERY LOW CHANCES OF RAIN
ACROSS THE MS RIVER DURING THE DAY...WHILE THE OTHER SHORT RANGE MODELS
WERE MORE TOWARD THE DRY SIDE. MOISTURE CONVERGENCE WILL CONTINUE TO
BE RATHER WEAK. THE NATIONAL WRF MODELS SHOWS SOME SHOWERS ACROSS
THE MS RIVER...WHILE THE NMM TRIES TO DEVELOP SOME SCATTERED CONVECTION
BY LATE SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING. NOT GOING FOR
THAT GIVEN THE WEAK SHORT WAVE. TO HAVE OPTED TO CONTINUE WITH LOWER
GMOS TEEN POPS FOR SUNDAY. HIGHS WILL BE FROM THE MID TO UPPER 80S.
WENT CLOSE TO MAV GUIDANCE. FOR SUNDAY NIGHT THE CHANCES OF RAIN
WILL DIMINISH AS THE SHORTWAVE CONTINUES TO WEAKEN AND LIMITED
MOISTURE CONVERGENCE ACROSS THE RIVER DIMINISHES. LOWS WILL BE FROM
THE MIDDLE 50S TO THE LOWER 60S. WENT CLOSE TO GMOS GUIDANCE./17/
.LONG TERM...MONDAY THROUGH SATURDAY...GENERALLY QUIET WEATHER WILL
PREVAIL IN THE BEGINNING OF THE PERIOD. THE REGION WILL REMAIN UNDER
RIDGING ALOFT AND ON THE WESTERN SIDE OF A DEPARTING SFC HIGH. THIS
WILL MAKE FOR DRY DAYS AS POCKETS OF DRIER AIR WILL PIVOT AROUND THE
SFC HIGH INTO AND THROUGH THE REGION. TEMPERATURES WILL BE ON THE
WARM SIDE DURING THE PERIOD AS HIGHS WILL REACH INTO THE UPPER 80S
TO AROUND 90 AND OVERNIGHT LOWS WILL BE IN THE 60S. DEEPER MOISTURE
WILL BEGIN TO MOVE IN BY WEDNESDAY AND THIS COULD HELP SUPPORT SOME
SHOWERS AND THUNDERSTORMS DESPITE LACK OF SIGNIFICANT FORCING. IT
APPEARS AS THOUGH MUCH OF THIS ACTIVITY WOULD BE DIURNALLY DRIVEN
AND HAVE LEFT SMALL POPS IN FOR THE AFTERNOON PERIODS OF MID WEEK
AND BEYOND. BY LATE IN THE PERIOD...MODELS SHOW AN UPPER LOW AND SFC
LOW ACROSS THE DAKOTAS. AS THIS TRACKS TO THE EAST BY THE END OF THE
PERIOD...IT BRINGS A FRONT CLOSE TO THE REGION. THIS MAY BRING A
BETTER SHOT OF RAIN FOR THE REGION BY THE END OF NEXT WEEKEND. /28/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL AS A COOL/DRY LATE MAY
AIRMASS KEEPS THE WEATHER QUIET ACROSS OUR CWA. LOOK FOR LIGHT ESE/SE
WINDS FOR TODAY. ISOLATED CONVECTION WILL BE POSSIBLE ACROSS THE MS
RIVER FOR TODAY AND TONIGHT./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 87 56 88 60 / 2 8 6 6
MERIDIAN 85 48 87 56 / 2 6 4 6
VICKSBURG 85 59 86 61 / 3 13 13 6
HATTIESBURG 88 58 87 59 / 1 4 4 5
NATCHEZ 85 61 84 61 / 4 11 15 7
GREENVILLE 84 60 88 64 / 3 9 13 5
GREENWOOD 84 55 88 61 / 2 8 9 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/28
000
FXUS64 KJAN 250145 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
845 PM CDT FRI MAY 24 2013
.UPDATE...EXPECT MOSTLY CLEAR SKIES TONIGHT ACROSS THE ARKLAMISS AS HIGH
PRESSURE CONTINUES TO BUILD IN. LOWS TONIGHT WILL RANGE FROM THE MID
40S IN THE EAST...TO THE UPPER 50S ACROSS THE WEST. THE ONLY CHANGE
TO THE CURRENT FORECAST WAS TO SLIGHTLY ADJUST THE HOURLY TEMPS TO
ACCOUNT FOR THE LATEST TRENDS. /27/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL AS A COOL/DRY LATE MAY
AIRMASS KEEPS THE WEATHER QUIET ACROSS OUR CWA. LOOK FOR LIGHT NE OR
CALM WINDS TONIGHT THAT WILL TRANSITION TO LIGHT ESE/SE WINDS ON
SATURDAY. /CME/
&&
.PREV DISCUSSION... /ISSUED 401 PM CDT FRI MAY 24 2013/
DISCUSSION...
TONIGHT THROUGH SUNDAY...
A FEW SHOWERS AND THUNDERSTORMS COULD AFFECT THE JONESVILLE TO
NATCHEZ AREA LATE THIS AFTERNOON IN A REGION OF WEAK MOIST FRONTAL
CONVERGENCE. OTHERWISE...HIGH PRESSURE CURRENTLY BUILDING OVER THE
ARKLAMISS WILL REMAIN ANCHORED OVER THE ARKLAMISS THIS WEEKEND. THE
DRY AIRMASS WILL BRING UNSEASONABLY COOL TEMPERATURES
TONIGHT...POSSIBLY NEAR RECORD LEVELS IN EASTERN MISSISSIPPI WHERE
LOWS ARE EXPECTED TO FALL INTO THE MID/UPPER 40S. TEMPERATURES WILL
WARM WELL INTO THE 80S SATURDAY WITH LOW RELATIVE HUMIDITY.
SUNDAY...A WEAK MID LEVEL SHORTWAVE TROUGH MEANDERING EASTWARD
THROUGH THE RIDGE AXIS ALONG THE MS RIVER COULD COMBINE WITH DAYTIME
HEATING TO INITIATE A FEW SHOWERS AND THUNDERSTORMS OVER WESTERN
PORTIONS OF THE FORECAST AREA. HAVE ADDED SLIGHT CHANCE CATEGORY
POPS TO ACCOUNT FOR THIS. /EC/
SUNDAY NIGHT THROUGH THURSDAY...
BUILDING MID LEVEL HEIGHTS AND SOUTHERLY LOW LEVEL FLOW WILL DEVELOP
AND PERSIST THROUGH THE EARLY TO MIDDLE PARTS OF NEXT WEEK. THIS WILL
LEAD TO HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S WITH GRADUALLY
INCREASING HUMIDITY. THE LACK OF INSTABILITY AND DEEP MOISTURE
COMBINED WITH THE HIGH HEIGHTS SHOULD KEEP CONDITIONS DRY THROUGH THE
PERIOD. /SW/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 53 87 58 88 / 0 0 6 5
MERIDIAN 47 84 50 89 / 0 0 5 4
VICKSBURG 56 86 60 87 / 0 2 9 13
HATTIESBURG 54 88 54 88 / 0 0 4 4
NATCHEZ 59 86 62 85 / 4 8 6 15
GREENVILLE 56 84 61 87 / 0 2 7 15
GREENWOOD 50 83 56 88 / 0 0 6 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
27/CME/EC/SW
000
FXUS64 KJAN 242101
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
401 PM CDT FRI MAY 24 2013
.DISCUSSION...
TONIGHT THROUGH SUNDAY...
A FEW SHOWERS AND THUNDERSTORMS COULD AFFECT THE JONESVILLE TO
NATCHEZ AREA LATE THIS AFTERNOON IN A REGION OF WEAK MOIST FRONTAL
CONVERGENCE. OTHERWISE...HIGH PRESSURE CURRENTLY BUILDING OVER THE
ARKLAMISS WILL REMAIN ANCHORED OVER THE ARKLAMISS THIS WEEKEND. THE
DRY AIRMASS WILL BRING UNSEASONABLY COOL TEMPERATURES
TONIGHT...POSSIBLY NEAR RECORD LEVELS IN EASTERN MISSISSIPPI WHERE
LOWS ARE EXPECTED TO FALL INTO THE MID/UPPER 40S. TEMPERATURES WILL
WARM WELL INTO THE 80S SATURDAY WITH LOW RELATIVE HUMIDITY.
SUNDAY...A WEAK MID LEVEL SHORTWAVE TROUGH MEANDERING EASTWARD
THROUGH THE RIDGE AXIS ALONG THE MS RIVER COULD COMBINE WITH DAYTIME
HEATING TO INITIATE A FEW SHOWERS AND THUNDERSTORMS OVER WESTERN
PORTIONS OF THE FORECAST AREA. HAVE ADDED SLIGHT CHANCE CATEGORY
POPS TO ACCOUNT FOR THIS. /EC/
&&
SUNDAY NIGHT THROUGH THURSDAY...
BUILDING MID LEVEL HEIGHTS AND SOUTHERLY LOW LEVEL FLOW WILL DEVELOP
AND PERSIST THROUGH THE EARLY TO MIDDLE PARTS OF NEXT WEEK. THIS WILL
LEAD TO HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S WITH GRADUALLY
INCREASING HUMIDITY. THE LACK OF INSTABILITY AND DEEP MOISTURE
COMBINED WITH THE HIGH HEIGHTS SHOULD KEEP CONDITIONS DRY THROUGH THE
PERIOD.
SW
&&
.AVIATION...
VFR WEATHER WITH LITTLE IN THE WAY OF AVIATION IMPACTS EXPECTED NEXT
24-36 HOURS. A BAND OF HIGH SC CONTINUES TO DRIFT SOUTH OF TAF SITES
AS HIGH PRESSURE AND DRIER AIR BUILDS INTO AREA. N-NE WINDS MAY
OCCASIONALLY GUST TO 20 KT AT TIMES FOR THE REST OF THE
AFTERNOON...BUT THIS SHOULD BE THE EXCEPTION RATHER THAN THE RULE.
COMBINATION OF WINDS STAYING UP AND DRIER LOW LEVEL AIR SHOULD
PRECLUDE ANY FOG DEVELOPMENT OVERNIGHT TONIGHT...WITH ONLY CLOUDS
BEING SOME OCCASIONAL PASSING CIRRUS ASSOCIATED WITH CONVECTIVE
DEBRIS FROM UPSTREAM COMPLEXES. /AEG/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 53 87 58 88 / 0 0 6 5
MERIDIAN 47 84 50 89 / 0 0 5 4
VICKSBURG 56 86 60 87 / 1 2 9 13
HATTIESBURG 54 88 54 88 / 0 0 4 4
NATCHEZ 59 86 62 85 / 6 8 6 15
GREENVILLE 56 84 61 87 / 0 2 7 15
GREENWOOD 50 83 56 88 / 0 0 6 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/AEG/SW
000
FXUS64 KJAN 241556
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1056 AM CDT FRI MAY 24 2013
.UPDATE...
THE FORECAST IS GENERALLY ON TRACK WITH THE ONLY SIGNIFICANT
ADJUSTMENT MADE TO EXTEND SLIGHT CHANCE POPS FURTHER IN TIME THIS
AFTERNOON. LATEST ANALYSIS SHOWS THE NW-SE ORIENTED SURFACE COLD
FRONT PUSHING SOUTHWEST INTO CENTRAL AND SOUTHEAST LOUISIANA. A
DISTINCT MOISTURE/INSTABILITY AXIS WITH ML CAPE > 2000 J/KG AND
PRECIP WATER >1.5 INCHES HAS SET UP ALONG THE FRONT...AND LATEST
GUIDANCE INDICATES IT MAY SUPPORT ISOLATED SHOWER/TSTM DEVELOPMENT
OVER THE NATCHEZ AREA FOR A LITTLE LONGER THAN EARLIER THOUGHT.
OTHERWISE...DRIER AIR WILL CONTINUE TO ADVECT IN FROM THE NORTHEAST
AS EVIDENT IN WATER VAPOR LOOP RESULTING IN LESS HUMID CONDITIONS.
THE UPDATED AVIATION DISCUSSION IS BELOW. /EC/
&&
.PREV DISCUSSION... /ISSUED 240 AM CDT FRI MAY 24 2013/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...
FOR TODAY AND TONIGHT...THE FRONT WILL PUSH SOUTH OF THE REGION AND
BE OVER THE GULF BY THIS AFTERNOON AS STRONG CANADIAN HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTH. BEFORE THE FRONTAL PASSAGE IN
THE SOUTH THERE WILL BE A SLIM CHANCE OF ISOLATED CONVECTION IN THE
SOUTHWEST UNTIL THE FRONTAL PASSAGE ALONG WITH SOME PATCHY FOG. THE
NATIONAL WRF MODELS SHOWED SOME ISOLATED CONVECTION IN THE
SOUTHWEST. THE SPC WRF LOOKED A LITTLE TOO AGGRESSIVE WITH STRONG
STORMS IN THE SOUTHWEST SPREADING NORTH PRIOR TO DAWN. AFTER THE
FRONTAL PASSAGE HIGH PRESSURE WILL PROVIDE GOOD DRYING IN THE LOW TO
MID LEVELS(PWATS FROM 0.4 EAST TO AROUND 1 INCH WEST) WITH SOME HIGH
CLOUDS COMING INTO THE REGION FROM NORTHWEST FLOW. AS FOR TEMPS HIGHS
WILL BE AROUND NORMAL WITH READINGS FROM THE UPPER 70S NORTH TO THE
MIDDLE 80S SOUTH. LOWS WILL WELL BELOW NORMAL WITH READINGS FROM THE
MIDDLE 40S EAST TO THE MIDDLE 50S WEST. THIS BRING THE RISK OF
BREAKING SOME RECORD LOWS IN THE EAST FOR EARLY SATURDAY. ON CLIMATE
STATS HATTIESBURG RECORD LOW OF 52 IN 1983 AND MERIDIANS LOW OF 47 IN
1979. FOR TEMPS WENT CLOSE TO MAV GUIDANCE.
FOR SATURDAY AND SATURDAY NIGHT... DURING THE PERIOD THE UPPER RIDGE
AXIS OVER THE PLAINS WILL MOVE TOWARD THE REGION. THE FRONT TO THE SOUTH
WILL COME BACK OVER THE REGION AS A WARM FRONT DURING THE PERIOD. A
WEAK SHORTWAVE WILL PUSH INTO THE REGION ON SATURDAY NIGHT ACCORDING
TO GFS. MODEL CROSS SECTIONS SHOWS DRY AIR IN THE LOW TO MID
LEVELS...WHILE THE UPPER LEVEL WILL CONTINUE TO BRING HIGH CLOUDS
FROM THE NORTHWEST. THE NAM MODEL KEEPS THE SHORTWAVE WEST OF THE
REGION FOR SATURDAY NIGHT. BOTH MODELS KEEPS THE PRECIP WEST OF THE
REGION. HIGHS ON SATURDAY WILL BE FROM THE LOWER TO MIDDLE 80S. LOWS
WILL CONTINUE TO BELOW NORMAL WITH READINGS FROM THE LOWER 50S EAST
TO THE AROUND 60 WEST./17/
LONG TERM...SUNDAY THROUGH THURSDAY...BUILDING MID LEVEL HEIGHTS
AND SOUTHERLY LOW LEVEL FLOW WILL DEVELOP AND PERSIST THROUGH THE
EARLY TO MIDDLE PARTS OF NEXT WEEK. THIS WILL LEAD TO HIGHS
GENERALLY IN THE MIDDLE TO UPPER 80S WITH GRADUALLY INCREASING
HUMIDITY. THE LACK OF INSTABILITY AND DEEP MOISTURE COMBINED WITH
THE HIGH HEIGHTS SHOULD KEEP CONDITIONS DRY THROUGH THE PERIOD.
SW
&&
.AVIATION...
VFR WEATHER WITH LITTLE IN THE WAY OF AVIATION IMPACTS EXPECTED NEXT
24-36 HOURS. A BAND OF HIGH SC RUNNING FROM SE AR TO NEAR KHBG IS
FAIRLY WELL DEPICTED IN 12Z NAM 925-850 MB MOISTURE FORECASTS. THIS
BAND IS PROGGED TO DRIFT S AND DISSIPATE NEXT 12 HOURS AS HIGH
PRESSURE AND DRIER AIR BUILDS INTO AREA. N-NE WINDS MAY OCCASIONALLY
GUST TO 20 KT AT TIME DURING PEAK MIXING THIE AFTERNOON. COMBINATION
OF WINDS STAYING UP AND DRIER LOW LEVEL AIR SHOULD PRECLUDE ANY FOG
DEVELOPMENT OVERNIGHT TONIGHT...WITH ONLY CLOUDS BEING SOME
OCCASIONALY PASSING HIGH CLOUDS ASSOCIATED WITH CONVECTIE DEBRIS FROM
UPSTREAM COMPLEXES. /AEG/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 86 51 85 55 / 6 4 3 8
MERIDIAN 87 44 85 50 / 4 4 3 6
VICKSBURG 82 53 85 54 / 7 4 3 12
HATTIESBURG 88 53 87 53 / 9 5 3 4
NATCHEZ 84 56 85 59 / 20 8 7 10
GREENVILLE 79 55 82 59 / 5 4 4 10
GREENWOOD 79 49 82 54 / 5 4 4 8
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
000
FXUS64 KJAN 240740
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
240 AM CDT FRI MAY 24 2013
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...
THE PRIMARY CONCERNS WILL BE THE ISSUE OF ISOLATED CONVECTION IN THE
SOUTHWEST UNTIL LATE MORNING AT THE TIME OF THE FRONTAL PASSAGE. THIS
FOLLOWED BY THE RISK OF A FEW RECORD LOWS FOR SATURDAY MORNING
FOLLOWED BY GENERALLY DRY CONDITIONS FOR THE PERIOD ALONG WITH TEMPS.
LATEST SATELLITE IMAGERY SHOWED THE REGION UNDER NORTHWEST FLOW
ALOFT...WHILE THE ARKLAMISS REGION WAS BEING FLANKED BY AN UPPER
RIDGE IN THE PLAINS AND AN UPPER TROUGH OVER THE EASTERN SEABOARD.
ON THE SURFACE A WEAK FRONT WAS SLOWLY PUSHING THROUGH THE REGION.
AREA RADARS WERE PICKING UP SOME ISOLATED SHOWERS OVER NORTHERN
LOUISIANA...WHICH WERENT LASTING LONG DUE TO WEAK MOISTURE
CONVERGENCE. COOL CANADIAN HIGH PRESSURE WAS NOTED OVER THE MID TO
UPPER MISSISSIPPI VALLEY WITH TEMPERATURES IN THE 40S AND
50S...WHICH WILL AFFECT OUR REGION AT NIGHT FOR THIS WEEKEND.
FOR TODAY AND TONIGHT...THE FRONT WILL PUSH SOUTH OF THE REGION AND
BE OVER THE GULF BY THIS AFTERNOON AS STRONG CANADIAN HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTH. BEFORE THE FRONTAL PASSAGE IN
THE SOUTH THERE WILL BE A SLIM CHANCE OF ISOLATED CONVECTION IN THE
SOUTHWEST UNTIL THE FRONTAL PASSAGE ALONG WITH SOME PATCHY FOG. THE NATIONAL
WRF MODELS SHOWED SOME ISOLATED CONVECTION IN THE SOUTHWEST IN THE MORNING
BEFORE WEAKENING IT AS IT HEADED NORTH INTO THE DRYER AIR. THE SPC
WRF LOOKED A LITTLE TOO AGGRESSIVE WITH STRONG STORMS IN THE
SOUTHWEST SPREADING NORTH PRIOR TO DAWN. AFTER THE FRONTAL PASSAGE
HIGH PRESSURE WILL PROVIDE GOOD DRYING IN THE LOW TO MID
LEVELS(PWATS FROM 0.4 EAST TO AROUND 1 INCH WEST) WITH SOME HIGH
CLOUDS COMING INTO THE REGION FROM NORTHWEST FLOW. AS FOR TEMPS
HIGHS WILL BE AROUND NORMAL WITH READINGS FROM THE UPPER 70S NORTH
TO THE MIDDLE 80S SOUTH. LOWS WILL WELL BELOW NORMAL WITH READINGS
FROM THE MIDDLE 40S EAST TO THE MIDDLE 50S WEST. THIS BRING THE RISK
OF BREAKING SOME RECORD LOWS IN THE EAST FOR EARLY SATURDAY. ON
CLIMATE STATS HATTIESBURG RECORD LOW OF 52 IN 1983 AND MERIDIANS LOW
OF 47 IN 1979. FOR TEMPS WENT CLOSE TO MAV GUIDANCE.
FOR SATURDAY AND SATURDAY NIGHT... DURING THE PERIOD THE UPPER RIDGE
AXIS OVER THE PLAINS WILL MOVE TOWARD THE REGION. THE FRONT TO THE SOUTH
WILL COME BACK OVER THE REGION AS A WARM FRONT DURING THE PERIOD. A
WEAK SHORTWAVE WILL PUSH INTO THE REGION ON SATURDAY NIGHT ACCORDING
TO GFS. MODEL CROSS SECTIONS SHOWS DRY AIR IN THE LOW TO MID
LEVELS...WHILE THE UPPER LEVEL WILL CONTINUE TO BRING HIGH CLOUDS
FROM THE NORTHWEST. THE NAM MODEL KEEPS THE SHORTWAVE WEST OF THE
REGION FOR SATURDAY NIGHT. BOTH MODELS KEEPS THE PRECIP WEST OF THE
REGION. HIGHS ON SATURDAY WILL BE FROM THE LOWER TO MIDDLE 80S. LOWS
WILL CONTINUE TO BELOW NORMAL WITH READINGS FROM THE LOWER 50S EAST
TO THE AROUND 60 WEST./17/
.LONG TERM...SUNDAY THROUGH THURSDAY...BUILDING MID LEVEL HEIGHTS
AND SOUTHERLY LOW LEVEL FLOW WILL DEVELOP AND PERSIST THROUGH THE
EARLY TO MIDDLE PARTS OF NEXT WEEK. THIS WILL LEAD TO HIGHS
GENERALLY IN THE MIDDLE TO UPPER 80S WITH GRADUALLY INCREASING
HUMIDITY. THE LACK OF INSTABILITY AND DEEP MOISTURE COMBINED WITH
THE HIGH HEIGHTS SHOULD KEEP CONDITIONS DRY THROUGH THE PERIOD.
SW
&&
.AVIATION...EXPECT A QUIET TAF PERIOD WITH VFR CONDITIONS PREVAILING
FOR MOST SITES. A WEAK SFC FRONT WILL PUSH SOUTH OF THE REGION THIS
MORNING. WITH GOOD MIXING EXPECTING MOSTLY VFR CONDITIONS THE
EXCEPTION MAY BE AT HBG AND WILL COVER WITH A 2HR TEMPO FOR 5SM. SKC
CONDITIONS FOR FRI WITH A NNE WIND AT 10-18KTS. WINDS WILL DECREASE
TO AROUND 6 KNOTS FROM THE NE BY 00Z./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 86 51 85 55 / 6 4 3 8
MERIDIAN 87 44 85 50 / 2 4 3 6
VICKSBURG 82 53 85 54 / 7 4 3 12
HATTIESBURG 88 53 87 53 / 6 5 3 4
NATCHEZ 84 56 85 59 / 17 8 7 10
GREENVILLE 79 55 82 59 / 3 4 4 10
GREENWOOD 79 49 82 54 / 2 4 4 8
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/SW
000
FXUS64 KJAN 240225 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
925 PM CDT THU MAY 23 2013
.UPDATE...
OVERALL THE REST OF THE EVENING SHOULD BE FAIRLY QUIET AS THE COLD
FRONT IS CURRENTLY SITUATED ALONG THE I-20 CORRIDOR. THIS FRONTAL
BOUNDARY SHOULD MOVE THROUGH THE REGION OVERNIGHT. HIGH INSTABILITY
AND UPPER S/WV IN THE H5 NORTHWEST FLOW AIDED IN SOME
SHOWER/THUNDERSTORM DEVELOPMENT IN THE FAR SOUTHWEST. KEPT SOME POPS
IN THE FAR SOUTHWEST FOR THE NEXT HOUR OR SO BEFORE THESE STORMS
WILL WEAKEN. DUE TO THIS ACTIVITY IN THE SOUTHWEST AND APPROACHING
HIGH CLOUDS FROM CONVECTIVE ACTIVITY IN THE TEXAS
PANHANDLE...INCREASED LOWS SLIGHTLY IN THE SOUTHWEST. ALSO REMOVED
PATCHY FOG FOR MOST AREAS DUE TO THE HIGH CLOUDS MOVING TONIGHT BUT
LEFT IT IN THE FAR SOUTHWEST DUE TO THE RAINFALL THAT HAS OCCURRED
TODAY. ADJUSTED HOURLY TEMPS/DEWPOINTS/SKY GRIDS ACCORDING TO
CURRENT TRENDS. REST OF THE FORECAST IS ON TRACK. /DC/
&&
.AVIATION...EXPECT A QUIETER TAF PERIOD THIS RUN WITH VFR CONDITIONS
PREVAILING FOR MOST SITES. A WEAK SFC FRONT HAS ENTERED THE NORTHER
CWA AND WILL CONTINUE TO PUSH SOUTH OVERNIGHT. ADDITIONALLY...DEEP
MIXING ALLOWED FOR LOWER 60 DEWPTS TO BE REALIZED ACROSS THE EASTERN
HALF OF THE AREA AND CROSSOVER TEMPS WILL BE TOUGH TO ACHIEVE...THUS
NOT EXPECTING VIS TO BE REDUCED. THE EXCEPTION MAY BE AT HBG AND
WILL COVER WITH A 2HR TEMPO FOR 5SM. SKC CONDITIONS FOR FRI WITH A
NNE WIND AT 10-15KTS. /CME/
&&
.PREV DISCUSSION... /ISSUED 400 PM CDT THU MAY 23 2013/
DISCUSSION...A BIT OF CONVECTION IS TRYING TO FORM CURRENTLY ACROSS
CENTRAL LOUISIANA IN AN AXIS OF HIGH INSTABILITY...MODEST MOISTURE
CONVERGENCE AND UPPER LEVEL ATMOSPHERIC LIFT. THIS IS BASICALLY
WHERE AN MCV (MESOSCALE CONVECTIVE VORTEX) EMBEDDED IN NORTHWEST
FLOW ALOFT IS IMPINGING ON A COLD FRONT OOZING SOUTH. BROAD SPECTRUM
OF GLOBAL NWP MODELS AND REGIONAL HIRES MODELS ARE STILL IN
DISAGREEMENT ON CONVECTIVE DEVELOPMENT THROUGH THIS EVENING IN OUR
VICINITY. OUR THINKING IS THAT THERE WILL LIKELY BE AT LEAST AN
ISOLATED STORM OR TWO IN SOUTHWEST ZONES LATE THIS AFTERNOON THROUGH
THIS EVENING WHICH COULD PRODUCE AT LEAST SOME BRIEF GUSTY WINDS OR
SMALL HAIL. THIS RISK WAS HIGHLIGHTED IN THE HWO. WE WILL ALSO HAVE
TO WATCH OUT FOR THE "WORST CASE SCENARIO" OFFERED BY A FEW HIRES
MODELS...WHICH IS A SMALL VIGOROUS THUNDERSTORM CLUSTER OR TWO
DEVELOPING OVER THE NEXT FEW HOURS AND PUSHING ACROSS SOUTHWEST HALF
OF ZONES THROUGH THIS EVENING. THIS WORSE CASE SCENARIO MIGHT BRING
A RISK FOR WIND GUSTS TO SEVERE LEVELS BUT FORTUNATELY LATEST TRENDS
SUGGEST THE WORST CASE SCENARIO NOT TOO LIKELY.
OTHERWISE FOR TONIGHT...ANTICIPATING THE COLD FRONT NOW SLIPPING
DOWN FROM THE NORTH TO PASS SLOWLY THROUGH MOST OF THE REGION BY
DAWN TOMORROW. ALTHOUGH THE AIR MASS TRYING TO COME IN BEHIND THE
BOUNDARY IS RELATIVELY COOL FOR THE DATE...CLOUDS AND SOME LINGERING
BREEZES WILL PREVENT OPTIMUM RADIATIONAL COOLING FROM OCCURRING. 12Z
MAV LOWS LOOKED GOOD...ADVERTISING A RANGE OF UPPER 50S NORTH TO MID
60S SOUTH. ALSO WORTH MENTIONING IS THAT THERE COULD BE SOME PATCHY
FOG IN SOUTHERN ZONES COME LATE TONIGHT...BUT FOG SHOULD DEFINITELY
NOT BE AS BIG OF AN ISSUE AS IT WAS THIS MORNING.
THROUGH TOMORROW AND INTO THE WEEKEND HIGH PRESSURE WILL TAKE UP
RESIDENCE OVER THE SOUTHEASTERN CONUS...ALTHOUGH THE COOLEST AND
DRIEST AIR WILL DEFINITELY BE CENTERED EAST AND NORTHEAST OR OUR
REGION. THE COLD FRONTAL BOUNDARY WILL STALL NOT TOO FAR TO OUR
SOUTHWEST AND COULD KICK OFF SOME MODEST CONVECTIVE ACTIVITY DURING
THIS TIME. FOR THAT REASON RAIN CHANCES WILL BE LOW...BUT NOT ZERO.
MORE OPERATIONALLY-SIGNIFICANT WILL LIKELY BE THE FACT THAT THE
CLOSE BOUNDARY AND INTERMITTENT CONVECTION TO OUR WEST SHOULD SHOOT
SOME HIGHER CLOUDS PERIODICALLY OUR WAY. THIS CLOUD COVER WILL
LIKELY KEEP TEMPERATURES A LITTLE WARMER TOMORROW NIGHT AND SATURDAY
NIGHT THAN THE EXTREMELY COOL 12Z MAV SUGGESTS. BUT EVEN RAISING 12
MAV LOWS FOR FRIDAY NIGHT A TOUCH SUGGESTS A FEW RECORD LOWS COULD
BE IN JEOPARDY FOR THE 25TH. HIGH TEMPERATURES SHOULD PROBABLY ONLY
BE A LITTLE BELOW AVERAGE IN MOST SPOTS...ALTHOUGH LOCATIONS UP
NORTH ALONG THE HIGHWAY 82 CORRIDOR COULD SEE HIGHS REMAINING IN THE
UPPER 70S TOMORROW.
THE FRONT WILL BE STARTING TO RETURN NORTH BY LATE SUNDAY AS A WEAK
DISTURBANCE PASSES TO OUR NORTH. THE INTERACTION OF THIS FRONT AND
THE DISTURBANCE WILL BRING CHANCES OF SHOWERS AND STORMS...BUT
MAINLY TO OUR NORTH. SO AFTER THIS EVENING WE HAVE KEPT THE FORECAST
DRY FOR ALL AREAS UNTIL AROUND THE MIDDLE OF NEXT WEEK. THE PREVIOUS
LONG RANGE DISCUSSION IS POSTED BELOW FOR REFERENCE. /BB/
PREV DISCUSSION... /ISSUED 415 AM CDT THU MAY 23 2013/
LONG TERM...(SUNDAY THROUGH THURSDAY) RIDGING BEGINS TO GIVE WAY
SATURDAY NIGHT WITH A SHORTWAVE MOVING THROUGH TO FLATTEN FLOW. THE
EURO IS ADVERTISING STRONGER FORCING WITH THIS WAVE AND BRINGS AN
AREA OF MOISTURE/PRECIP ACROSS NRN ZONES FOR SUNDAY. THE HIGHER POPS
CALLED FOR BY THE EURO FOR MONDAY AFTER THE WAVES PASSES LOOK A
LITTLE OUT OF WHACK...WEAK ISENTROPIC FLOW NOTWITHSTANDING...AND THE
MORE CONSISTENT DRY FORECAST PER THE GFS WILL BE FOLLOWED FOR NOW.
MODEL SOLUTIONS CONTINUE TO DIFFER IN THE FARTHER PERIODS OF THE
EXTENDED REGARDING PLACEMENT OF THE UPPER RIDGELINE AND SHORTWAVES
THAT PUSH THROUGH BUT THE GENERAL PATTERN WILL BE LOW LEVEL SLY FLOW
IN A REGION OF WEAK UPPER FORCING POSSIBLE DEPENDING ON WHERE THE
RIDGE/TROUGH POSITIONS SET UP. IN THIS TYPE OF REGIME THE CHANCE OF
AFTERNOON CONVECTION...EVEN WITHOUT SIGNIFICANT FORCING...WILL
GRADUALLY BE ON THE INCREASE DUE TO PERSISTENT SLY FLOW THAT WILL BE
IN PLACE. HOWEVER MODELS ARE ALSO SUGGESTING A POTENTIAL FOR CAPPING
DUE TO THE PROXIMITY OF THE UPPER RIDGE. DUE TO THESE UNCERTAINTIES
THE DRIER GFS WILL BE FOLLOWED FOR NOW. /03/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 64 83 52 84 / 11 6 2 2
MERIDIAN 61 82 46 84 / 8 2 0 0
VICKSBURG 65 82 54 85 / 13 7 5 6
HATTIESBURG 67 86 51 86 / 10 5 3 2
NATCHEZ 69 83 55 83 / 15 9 5 7
GREENVILLE 63 79 54 82 / 11 3 2 4
GREENWOOD 59 78 50 82 / 7 1 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/CME/BB/03
000
FXUS64 KJAN 232058
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
400 PM CDT THU MAY 23 2013
.DISCUSSION...A BIT OF CONVECTION IS TRYING TO FORM CURRENTLY ACROSS
CENTRAL LOUISIANA IN AN AXIS OF HIGH INSTABILITY...MODEST MOISTURE
CONVERGENCE AND UPPER LEVEL ATMOSPHERIC LIFT. THIS IS BASICALLY
WHERE AN MCV (MESOSCALE CONVECTIVE VORTEX) EMBEDDED IN NORTHWEST
FLOW ALOFT IS IMPINGING ON A COLD FRONT OOZING SOUTH. BROAD SPECTRUM
OF GLOBAL NWP MODELS AND REGIONAL HIRES MODELS ARE STILL IN
DISAGREEMENT ON CONVECTIVE DEVELOPMENT THROUGH THIS EVENING IN OUR
VICINITY. OUR THINKING IS THAT THERE WILL LIKELY BE AT LEAST AN
ISOLATED STORM OR TWO IN SOUTHWEST ZONES LATE THIS AFTERNOON THROUGH
THIS EVENING WHICH COULD PRODUCE AT LEAST SOME BRIEF GUSTY WINDS OR
SMALL HAIL. THIS RISK WAS HIGHLIGHTED IN THE HWO. WE WILL ALSO HAVE
TO WATCH OUT FOR THE "WORST CASE SCENARIO" OFFERED BY A FEW HIRES
MODELS...WHICH IS A SMALL VIGOROUS THUNDERSTORM CLUSTER OR TWO
DEVELOPING OVER THE NEXT FEW HOURS AND PUSHING ACROSS SOUTHWEST HALF
OF ZONES THROUGH THIS EVENING. THIS WORSE CASE SCENARIO MIGHT BRING
A RISK FOR WIND GUSTS TO SEVERE LEVELS BUT FORTUNATELY LATEST TRENDS
SUGGEST THE WORST CASE SCENARIO NOT TOO LIKELY.
OTHERWISE FOR TONIGHT...ANTICIPATING THE COLD FRONT NOW SLIPPING
DOWN FROM THE NORTH TO PASS SLOWLY THROUGH MOST OF THE REGION BY
DAWN TOMORROW. ALTHOUGH THE AIR MASS TRYING TO COME IN BEHIND THE
BOUNDARY IS RELATIVELY COOL FOR THE DATE...CLOUDS AND SOME LINGERING
BREEZES WILL PREVENT OPTIMUM RADIATIONAL COOLING FROM OCCURRING. 12Z
MAV LOWS LOOKED GOOD...ADVERTISING A RANGE OF UPPER 50S NORTH TO MID
60S SOUTH. ALSO WORTH MENTIONING IS THAT THERE COULD BE SOME PATCHY
FOG IN SOUTHERN ZONES COME LATE TONIGHT...BUT FOG SHOULD DEFINITELY
NOT BE AS BIG OF AN ISSUE AS IT WAS THIS MORNING.
THROUGH TOMORROW AND INTO THE WEEKEND HIGH PRESSURE WILL TAKE UP
RESIDENCE OVER THE SOUTHEASTERN CONUS...ALTHOUGH THE COOLEST AND
DRIEST AIR WILL DEFINITELY BE CENTERED EAST AND NORTHEAST OR OUR
REGION. THE COLD FRONTAL BOUNDARY WILL STALL NOT TOO FAR TO OUR
SOUTHWEST AND COULD KICK OFF SOME MODEST CONVECTIVE ACTIVITY DURING
THIS TIME. FOR THAT REASON RAIN CHANCES WILL BE LOW...BUT NOT ZERO.
MORE OPERATIONALLY-SIGNIFICANT WILL LIKELY BE THE FACT THAT THE
CLOSE BOUNDARY AND INTERMITTENT CONVECTION TO OUR WEST SHOULD SHOOT
SOME HIGHER CLOUDS PERIODICALLY OUR WAY. THIS CLOUD COVER WILL
LIKELY KEEP TEMPERATURES A LITTLE WARMER TOMORROW NIGHT AND SATURDAY
NIGHT THAN THE EXTREMELY COOL 12Z MAV SUGGESTS. BUT EVEN RAISING 12
MAV LOWS FOR FRIDAY NIGHT A TOUCH SUGGESTS A FEW RECORD LOWS COULD
BE IN JEOPARDY FOR THE 25TH. HIGH TEMPERATURES SHOULD PROBABLY ONLY
BE A LITTLE BELOW AVERAGE IN MOST SPOTS...ALTHOUGH LOCATIONS UP
NORTH ALONG THE HIGHWAY 82 CORRIDOR COULD SEE HIGHS REMAINING IN THE
UPPER 70S TOMORROW.
THE FRONT WILL BE STARTING TO RETURN NORTH BY LATE SUNDAY AS A WEAK
DISTURBANCE PASSES TO OUR NORTH. THE INTERACTION OF THIS FRONT AND
THE DISTURBANCE WILL BRING CHANCES OF SHOWERS AND STORMS...BUT
MAINLY TO OUR NORTH. SO AFTER THIS EVENING WE HAVE KEPT THE FORECAST
DRY FOR ALL AREAS UNTIL AROUND THE MIDDLE OF NEXT WEEK. THE PREVIOUS
LONG RANGE DISCUSSION IS POSTED BELOW FOR REFERENCE. /BB/
&&
.PREV DISCUSSION... /ISSUED 415 AM CDT THU MAY 23 2013/
LONG TERM...(SUNDAY THROUGH THURSDAY) RIDGING BEGINS TO GIVE WAY
SATURDAY NIGHT WITH A SHORTWAVE MOVING THROUGH TO FLATTEN FLOW. THE
EURO IS ADVERTISING STRONGER FORCING WITH THIS WAVE AND BRINGS AN
AREA OF MOISTURE/PRECIP ACROSS NRN ZONES FOR SUNDAY. THE HIGHER POPS
CALLED FOR BY THE EURO FOR MONDAY AFTER THE WAVES PASSES LOOK A
LITTLE OUT OF WHACK...WEAK ISENTROPIC FLOW NOTWITHSTANDING...AND THE
MORE CONSISTENT DRY FORECAST PER THE GFS WILL BE FOLLOWED FOR NOW.
MODEL SOLUTIONS CONTINUE TO DIFFER IN THE FARTHER PERIODS OF THE
EXTENDED REGARDING PLACEMENT OF THE UPPER RIDGELINE AND SHORTWAVES
THAT PUSH THROUGH BUT THE GENERAL PATTERN WILL BE LOW LEVEL SLY FLOW
IN A REGION OF WEAK UPPER FORCING POSSIBLE DEPENDING ON WHERE THE
RIDGE/TROUGH POSITIONS SET UP. IN THIS TYPE OF REGIME THE CHANCE OF
AFTERNOON CONVECTION...EVEN WITHOUT SIGNIFICANT FORCING...WILL
GRADUALLY BE ON THE INCREASE DUE TO PERSISTENT SLY FLOW THAT WILL BE
IN PLACE. HOWEVER MODELS ARE ALSO SUGGESTING A POTENTIAL FOR CAPPING
DUE TO THE PROXIMITY OF THE UPPER RIDGE. DUE TO THESE UNCERTAINTIES
THE DRIER GFS WILL BE FOLLOWED FOR NOW. /03/
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO PREVAIL TONIGHT THROUGH
FRIDAY AND SATURDAY. A LINGERING FRONTAL BOUNDARY WILL PROVIDE THE
OPPORTUNITY FOR A FEW STORMS TO DEVELOP LATE THIS AFTERNOON AND
EVENING... ESPECIALLY OVER SOUTHWESTERN PORTIONS OF THE FORECAST
AREA... POTENTIALLY AFFECTING THE TVR/HEZ CORRIDOR. THERE COULD BE A
PERIOD OF IFR/MVFR STRATUS LATE TONIGHT AND EARLY FRIDAY MORNING IN
INCREASING NORTHEAST LOW-LEVEL FLOW AND COOL AIR ADVECTION...BUT THE
DRIER AIR AND INCREASED FLOW SHOULD LIMIT FOG POTENTIAL. IT APPEARS
THE GREATEST RISK FOR ANY FOG WOULD BE IN THE PIB/HBG AREA. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 63 83 52 84 / 15 6 2 2
MERIDIAN 60 82 46 84 / 9 2 0 0
VICKSBURG 64 82 54 85 / 29 7 5 6
HATTIESBURG 65 86 51 86 / 15 5 3 2
NATCHEZ 66 83 55 83 / 33 9 5 7
GREENVILLE 62 79 54 82 / 13 3 2 4
GREENWOOD 58 78 50 82 / 8 1 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/EC/03
000
FXUS64 KJAN 231549 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE JACKSON MS
1045 AM CDT THU MAY 23 2013
.UPDATE...COLD FRONT THIS MORNING TRYING TO SLOWLY ORIENT MORE WEST
TO EAST AND SAG SOUTH INTO FAR NORTHERN ZONES. SOUTH OF THIS
BOUNDARY PATCHY LOW CLOUDS AND FOG FORMING LAST NIGHT ARE BURNING
OFF...BUT STILL WILL HAVE SOME OBSERVABLE REMNANT FOR ANOTHER HOUR
OR SO ACROSS PORTIONS OF CENTRAL MS STRETCHING BACK WEST TO NE LA
AND EXTREME SE AR. SOMEWHAT PERTURBED NORTHWEST FLOW EXISTS FROM THE
PLAINS SOUTHEAST ACROSS THE LOWER MS VALLEY THIS MORNING...WITH THE
LOW LEVEL JET FEEDING A CLUSTER OF THUNDERSTORMS ACROSS CENTRAL OK
AND MOVING INTO THE RED RIVER VALLEY.
FOR OUR REGION INSTABILITY IS EXPECTED TO BUILD ALONG AND SOUTH OF
SOUTHWARD SAGGING COLD FRONT AS THE DAY GOES ON...PARTICULARLY IN
WESTERN ZONES WHERE STEEP LAPSE RATES AND BOUNDARY LAYER HEAT AND
HUMIDITY WILL YIELD UP TO 2500 J/KG MLCAPE BY LATE AFTERNOON. MOST
AVAILABLE HI RES MODELS DEPICT AT LEAST ONE SMALL THUNDERSTORM
CLUSTER DEVELOPING ALONG THE BOUNDARY IN THE VICINITY OF THE
ARKLAMISS DELTA BETWEEN LATE AFTERNOON AND EARLY EVENING...THEN
DIVING SOUTHEASTWARD. HOWEVER...SOME GLOBAL MODELS (SUCH AS THE
ECMWF) DEVELOP NO AT ALL. DEVELOPMENT IS INDEED QUESTIONABLE DUE
TO CAPPING AND POTENTIALLY LIMITED FORCING. HOWEVER...FOR THIS
UPDATE...AM LEANING IN THE DIRECTION THAT AT LEAST A BIT OF
THUNDERSTORM ACTIVITY WILL GET GOING BECAUSE OF LIKELIHOOD OF LIFT
BEING ENHANCED BY MCV INITIATED BY OK CONVECTION COMING INTO THE
FRAY BY 00 UTC. FOR THAT REASON UPPED POPS TO 30 PERCENT IN MANY
NORTHWEST AND WEST CENTRAL ZONES THIS EVENING.
WE ALREADY HAVE RISK OF STRONG STORMS IN THE HWO FOR LATE THIS
AFTERNOON AND THIS EVENING ALONG AND WEST OF I-55. HIGHEST RISK WILL
LIKELY BE MORE CONFINED TO THE ARKLAMISS DELTA...BUT WILL LEAVE
WORDING AND AREA GOING FOR NOW BECAUSE OF UNCERTAINTIES INVOLVED.
DEFINITELY SOME CHANCE FOR A FEW SEVERE WIND GUSTS IN NORTHWEST
ZONES IF THE WORST CASE SCENARIO OF BEING AFFECTED BY A SOMEWHAT
ORGANIZED THUNDERSTORM COMPLEX COMES TO FRUITION. WE WILL BE
MONITORING FOR THAT POTENTIAL CLOSELY AND WILL UPDATE PRODUCTS
QUICKLY IF NEED BE. /BB/
&&
.PREV DISCUSSION... /ISSUED 415 AM CDT THU MAY 23 2013/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT...
THE PRIMARY CONCERNS WILL BE THE RISK OF A FEW STRONG STORMS FOR
THE LATER HALF OF THIS AFTERNOON INTO THIS EVENING ACROSS THE WEST
HALF OF THE REGION. ALSO THE RISK OF AREAS OF DENSE FOG ACROSS THE
REGION FOR THIS MORNING. THIS FOLLOWED BY POPS AND TEMPS.
LATEST SATELLITE IMAGERY SHOWED THE REGION UNDER NORTHWEST FLOW
ALOFT WITH THE BASE OF AN UPPER TROUGH OVER THE MIDSOUTH REGION.
A FRONT WAS APPROACHING THE REGION FROM NORTHERN ARKANSAS. SURFACE
HIGH PRESSURE WAS NOTED ACROSS THE REGION. LIGHT WINDS AND A LOW
LEVEL MOIST BOUNDARY LAYER WITH MOSTLY CLEAR SKIES HAD HELP AREAS OF
OCCASIONALLY DENSE FOG TO FORM ACROSS THE REGION. VISIBILITIES HAVE
BEEN BOUNCING UP AND DOWN.
FOR TODAY AND TONIGHT...WITH AREAS OF FOG AROUND. WILL PUT AREAS OF
OCCASIONALLY DENSE FOG ACROSS THE ENTIRE FORECAST AREA AS
VISIBILITIES BOUNCE UP AND DOWN. ALSO OF CONCERN THERE WILL BE
ENOUGH INSTABILITY(ML CAPES >3000 J/KG, LAPSE RATE AROUND 7C,
LINGERING FRONTAL BOUNDARY COMING INTO THE REGION, INCREASING
MOISTURE CONVERGENCE FOR A FEW STRONG STORMS TO DEVELOP FOR THIS
AFTERNOON AND EVENING. THE WRF MODELS ESP THE SPC WRF SHOWS A FEW
STRONG STORMS COMING OUT OF SOUTHERN ARKANSAS AND LOUISIANA TOWARD
THE REGION BY MID AFTERNOON. AREA SOUNDINGS LOOK A LITTLE DRY ESP UP
IN THE MID LEVELS WITH A CAP IN PLACE...BUT THE FRONTAL BOUNDARY MAY
BE THE FOCUS MECHANISM TO GET A FEW STORMS GOING. WILL MENTION IN
HWO BOTH FOG POTENTIAL AND STRONG STORMS. THE INTENSITY OF THE FEW
STRONG STORMS SHOULD DECREASE DURING THE EVENING HOURS. THE SPC WRF
KEEPS THE CONVECTION GOING AFTER MIDNIGHT AND PUSHES IT ACROSS THE
EAST HALF OF THE REGION. HIGHS TODAY WILL BE MID TO UPPER 80S. LOWS
WILL BE FROM THE UPPER 50S TO THE MIDDLE 60S...WHICH IS AROUND
NORMAL FOR THIS TIME OF YEAR. WENT CLOSE TO MAV GUIDANCE. AS FOR
POPS PUT IN LOW POPS FOR TODAY WITH THE SPC WRF IN MIND. MODEL POPS
WERE RATHER DRY PROBABLY DUE TO THE SOMEWHAT DRY SOUNDINGS. MADE
SLIGHT ADJUSTMENTS TO MAV POPS FOR TONIGHT.
FOR FRIDAY AND FRIDAY NIGHT...UPPER RIDGE AXIS OVER THE PLAINS WILL
DEVELOP TOWARD THE REGION. COOL SURFACE HIGH PRESSURE MOVING FROM
THE UPPER MISSISSIPPI VALLEY TO THE GREAT LAKES WILL PROVIDE DRY
WEATHER TO THE REGION. HIGHS ON FRIDAY WILL BE FROM THE MIDDLE 70S
NORTH TO THE UPPER 80S SOUTH. LOWS FRIDAY NIGHT WILL RANGE FROM THE
COOL UPPER 40S EAST TO THE MIDDLE TO UPPER 50S WEST...WHICH WILL BE
WELL BELOW NORMAL. WENT CLOSE TO MAV GUIDANCE./17/
LONG TERM...(SATURDAY THROUGH THURSDAY) HIGH PRESSURE WILL BE IN
CONTROL OF REGIONAL WEATHER SATURDAY. RIDGING BEGINS TO GIVE WAY
SATURDAY NIGHT WITH A SHORTWAVE MOVING THROUGH TO FLATTEN FLOW. THE
EURO IS ADVERTISING STRONGER FORCING WITH THIS WAVE AND BRINGS AN
AREA OF MOISTURE/PRECIP ACROSS NRN ZONES FOR SUNDAY. THE HIGHER POPS
CALLED FOR BY THE EURO FOR MONDAY AFTER THE WAVES PASSES LOOK A
LITTLE OUT OF WHACK...WEAK ISENTROPIC FLOW NOTWITHSTANDING...AND THE
MORE CONSISTENT DRY FORECAST PER THE GFS WILL BE FOLLOWED FOR NOW.
MODEL SOLUTIONS CONTINUE TO DIFFER IN THE FARTHER PERIODS OF THE
EXTENDED REGARDING PLACEMENT OF THE UPPER RIDGELINE AND SHORTWAVES
THAT PUSH THROUGH BUT THE GENERAL PATTERN WILL BE LOW LEVEL SLY FLOW
IN A REGION OF WEAK UPPER FORCING POSSIBLE DEPENDING ON WHERE THE
RIDGE/TROUGH POSITIONS SET UP. IN THIS TYPE OF REGIME THE CHANCE OF
AFTERNOON CONVECTION...EVEN WITHOUT SIGNIFICANT FORCING...WILL
GRADUALLY BE ON THE INCREASE DUE TO PERSISTENT SLY FLOW THAT WILL BE
IN PLACE. HOWEVER MODELS ARE ALSO SUGGESTING A POTENTIAL FOR CAPPING
DUE TO THE PROXIMITY OF THE UPPER RIDGE. DUE TO THESE UNCERTAINTIES
THE DRIER GFS WILL BE FOLLOWED FOR NOW.
&&
.AVIATION...MORNING FOG AND STRATUS HAS JUST ABOUT MIXED OUT AND VFR
CONDITIONS ARE EXPECTED TO PREVAIL THIS AFTERNOON THROUGH TONIGHT. A
LINGERING FRONTAL BOUNDARY WILL PROVIDE THE OPPORTUNITY FOR A FEW
STORMS TO DEVELOP LATE THIS AFTERNOON INTO THE EVENING...ESPECIALLY
OVER WESTERN PORTIONS OF THE FORECAST AREA INCLUDING GLH. WILL NOT
INCLUDE A MENTION OF STORMS IN THE TAFS DUE TO LIMITED COVERAGE.
OTHERWISE...FOG DEVELOPMENT FOR LATE TONIGHT AND EARLY FRIDAY
MORNING IS QUESTIONABLE WITH DRY AIR ADVECTION EXPECTED TO TAKE
PLACE IN INCREASING NORTHEAST LOW-LEVEL FLOW. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 89 63 83 52 / 9 22 6 6
MERIDIAN 89 61 85 47 / 5 12 7 5
VICKSBURG 89 63 82 52 / 16 29 5 5
HATTIESBURG 91 65 88 53 / 5 16 2 3
NATCHEZ 88 65 84 56 / 14 24 5 6
GREENVILLE 88 64 78 54 / 21 21 7 5
GREENWOOD 87 61 78 50 / 12 15 9 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/EC/17/03
000
FXUS64 KJAN 230918
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
415 AM CDT THU MAY 23 2013
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT...
THE PRIMARY CONCERNS WILL BE THE RISK OF A FEW STRONG STORMS FOR
THE LATER HALF OF THIS AFTERNOON INTO THIS EVENING ACROSS THE WEST
HALF OF THE REGION. ALSO THE RISK OF AREAS OF DENSE FOG ACROSS THE
REGION FOR THIS MORNING. THIS FOLLOWED BY POPS AND TEMPS.
LATEST SATELLITE IMAGERY SHOWED THE REGION UNDER NORTHWEST FLOW
ALOFT WITH THE BASE OF AN UPPER TROUGH OVER THE MIDSOUTH REGION.
A FRONT WAS APPROACHING THE REGION FROM NORTHERN ARKANSAS. SURFACE
HIGH PRESSURE WAS NOTED ACROSS THE REGION. LIGHT WINDS AND A LOW LEVEL
MOIST BOUNDARY LAYER WITH MOSTLY CLEAR SKIES HAD HELP AREAS OF OCCASIONALLY
DENSE FOG TO FORM ACROSS THE REGION. VISIBILITIES HAVE BEEN BOUNCING
UP AND DOWN.
FOR TODAY AND TONIGHT...WITH AREAS OF FOG AROUND. WILL PUT AREAS OF
OCCASIONALLY DENSE FOG ACROSS THE ENTIRE FORECAST AREA AS
VISIBILITIES BOUNCE UP AND DOWN. ALSO OF CONCERN THERE WILL BE
ENOUGH INSTABILITY(ML CAPES >3000 J/KG, LAPSE RATE AROUND 7C,
LINGERING FRONTAL BOUNDARY COMING INTO THE REGION, INCREASING
MOISTURE CONVERGENCE FOR A FEW STRONG STORMS TO DEVELOP FOR THIS
AFTERNOON AND EVENING. THE WRF MODELS ESP THE SPC WRF SHOWS A FEW
STRONG STORMS COMING OUT OF SOUTHERN ARKANSAS AND LOUISIANA TOWARD
THE REGION BY MID AFTERNOON. AREA SOUNDINGS LOOK A LITTLE DRY ESP UP
IN THE MID LEVELS WITH A CAP IN PLACE...BUT THE FRONTAL BOUNDARY MAY
BE THE FOCUS MECHANISM TO GET A FEW STORMS GOING. WILL MENTION IN
HWO BOTH FOG POTENTIAL AND STRONG STORMS. THE INTENSITY OF THE FEW
STRONG STORMS SHOULD DECREASE DURING THE EVENING HOURS. THE SPC WRF
KEEPS THE CONVECTION GOING AFTER MIDNIGHT AND PUSHES IT ACROSS THE
EAST HALF OF THE REGION. HIGHS TODAY WILL BE MID TO UPPER 80S. LOWS
WILL BE FROM THE UPPER 50S TO THE MIDDLE 60S...WHICH IS AROUND
NORMAL FOR THIS TIME OF YEAR. WENT CLOSE TO MAV GUIDANCE. AS FOR
POPS PUT IN LOW POPS FOR TODAY WITH THE SPC WRF IN MIND. MODEL POPS
WERE RATHER DRY PROBABLY DUE TO THE SOMEWHAT DRY SOUNDINGS. MADE
SLIGHT ADJUSTMENTS TO MAV POPS FOR TONIGHT.
FOR FRIDAY AND FRIDAY NIGHT...UPPER RIDGE AXIS OVER THE PLAINS WILL DEVELOP
TOWARD THE REGION. COOL SURFACE HIGH PRESSURE MOVING FROM THE UPPER
MISSISSIPPI VALLEY TO THE GREAT LAKES WILL PROVIDE DRY WEATHER TO
THE REGION. HIGHS ON FRIDAY WILL BE FROM THE MIDDLE 70S NORTH TO THE
UPPER 80S SOUTH. LOWS FRIDAY NIGHT WILL RANGE FROM THE COOL UPPER
40S EAST TO THE MIDDLE TO UPPER 50S WEST...WHICH WILL BE WELL BELOW
NORMAL. WENT CLOSE TO MAV GUIDANCE./17/
.LONG TERM...(SATURDAY THROUGH THURSDAY) HIGH PRESSURE WILL BE IN
CONTROL OF REGIONAL WEATHER SATURDAY. RIDGING BEGINS TO GIVE WAY
SATURDAY NIGHT WITH A SHORTWAVE MOVING THROUGH TO FLATTEN FLOW. THE
EURO IS ADVERTISING STRONGER FORCING WITH THIS WAVE AND BRINGS AN
AREA OF MOISTURE/PRECIP ACROSS NRN ZONES FOR SUNDAY. THE HIGHER POPS
CALLED FOR BY THE EURO FOR MONDAY AFTER THE WAVES PASSES LOOK A
LITTLE OUT OF WHACK...WEAK ISENTROPIC FLOW NOTWITHSTANDING...AND THE
MORE CONSISTENT DRY FORECAST PER THE GFS WILL BE FOLLOWED FOR NOW.
MODEL SOLUTIONS CONTINUE TO DIFFER IN THE FARTHER PERIODS OF THE
EXTENDED REGARDING PLACEMENT OF THE UPPER RIDGELINE AND SHORTWAVES
THAT PUSH THROUGH BUT THE GENERAL PATTERN WILL BE LOW LEVEL SLY FLOW
IN A REGION OF WEAK UPPER FORCING POSSIBLE DEPENDING ON WHERE THE
RIDGE/TROUGH POSITIONS SET UP. IN THIS TYPE OF REGIME THE CHANCE OF
AFTERNOON CONVECTION...EVEN WITHOUT SIGNIFICANT FORCING...WILL
GRADUALLY BE ON THE INCREASE DUE TO PERSISTENT SLY FLOW THAT WILL BE
IN PLACE. HOWEVER MODELS ARE ALSO SUGGESTING A POTENTIAL FOR CAPPING
DUE TO THE PROXIMITY OF THE UPPER RIDGE. DUE TO THESE UNCERTAINTIES
THE DRIER GFS WILL BE FOLLOWED FOR NOW.
&&
.AVIATION...CURRENTLY WE HAVE AREAS OF DENSE FOG (IFR CONDITIONS)
ACROSS THE REGION WITH VISIBILITIES BOUNCING UP AND DOWN. EXPECT THE
FOG TO LIFT BY 14-15Z. ALSO ISOLATED STRONG STORMS WILL BE POSSIBLE
GENERALLY ALONG AND WEST OF INTERSTATE 55. COVERAGE WILL BE MINIMAL
AS FAR AS AFFECTING TAF SITES. BUT IF THEY DO AFFECT ANY ONE OF THE TAF
SITES GLH GWO KHKS AND KJAN...COULD PROVIDE SOME BRIEF GUSTY WINDS
OF AROUND 30-40 KNOTS AND SOME SMALL HAIL THROUGH EARLY THIS
EVENING. WINDS WILL BE VARIABLE AT 5-7 KNOTS./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 88 63 83 52 / 16 19 6 6
MERIDIAN 89 61 85 47 / 12 17 7 5
VICKSBURG 88 63 82 52 / 16 23 5 5
HATTIESBURG 90 65 88 53 / 12 20 2 3
NATCHEZ 87 65 84 56 / 16 23 5 6
GREENVILLE 88 64 78 54 / 16 21 7 5
GREENWOOD 87 61 78 50 / 15 19 9 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/03
000
FXUS64 KJAN 230225 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
925 PM CDT WED MAY 22 2013
.UPDATE...
REGIONAL 00Z SOUNDING ANALYSIS INDICATES MID/UPPER LEVELS DRYING TO
THE WEST AND CLOUDS HAVE BEGUN TO CLEAR ACROSS MOST OF THE REGION.
SLIGHTLY MODIFIED SKY COVER GRIDS TO ACCOUNT FOR FASTER CLEARING OF
CLOUDS. REMOVED POPS FOR TONIGHT AS ISOLATED ACTIVITY HAS WANED AND
MOVED OUT OF THE REGION. TEMPERATURES WERE SLIGHTLY COOLER AND
ADJUSTED HOURLY TEMP/DEWPOINT GRIDS CLOSER TO LAV. MID/UPPER LEVEL
DRYING...LIGHT SURFACE WINDS...DECENT RADIATIONAL COOLING AND RECENT
RAINFALL WILL AID IN SOME AREAS OF PATCHY DENSE FOG. THE MOST LIKELY
AREA FOR SOME PATCHY DENSE FOG WILL EXIST MAINLY ALONG AND SOUTHEAST
OF THE NATCHEZ TRACE CORRIDOR THEN LIFT AROUND 14-15Z. WILL HOLD OFF
ON DENSE FOG ADVISORY UNTIL MORE CERTAINTY ON FOG ACTUALLY DEVELOPING
AND WHERE IT WOULD DEVELOP. REST OF THE FORECAST IS ON TRACK.
THURSDAY AFTERNOON TO EVENING
THE REGION WILL STAY SITUATED UNDER NORTHWESTERLY FLOW ALOFT AND A
WEAK S/WV MAY AID IN SOME POSSIBLE THUNDERSTORM ACTIVITY TOMORROW IN
VICINITY OF THE LINGERING FRONTAL BOUNDARY. STEEP LAPSE RATES AND
VERTICAL TOTALS APPROACHING 28-30 COULD SUPPORT SOME ROBUST
THUNDERSTORM DEVELOPMENT. HOWEVER...THERE IS STILL SOME UNCERTAINTY
IF ANYTHING WILL DEVELOP. WILL WAIT FOR NEW GUIDANCE TO SEE IF IT
RESOLVES ANY DEVELOPMENT. /DC/
&&
.AVIATION...QUIET EVENING ACROSS THE REGION WITH VFR CONDITIONS
PREVAILING. THINKING IS THAT SOME OF THE CWA WILL SEE FOG
DEVELOPMENT (MAINLY S/SE AREAS) AND WILL HAVE CONDITIONS DROPPING TO
MVFR THEN IFR AT HBG/MEI. CONDITIONS SHOULD IMPROVE QUICKLY AND WILL
TREND TAFS TO VFR AROUND 14Z. /CME/
&&
.PREV DISCUSSION... /ISSUED 409 PM CDT WED MAY 22 2013/
TONIGHT THROUGH THURSDAY NIGHT...
DESTABILIZATION WAS INSUFFICIENT FOR GETTING SUBSTANTIAL
SHOWER/THUNDERSTORM ACTIVITY THIS AFTERNOON IN THE WAKE OF THE
MORNING CONVECIVE SYSTEM. RAIN CHANCES WILL CONTINUE TO DECREASE
TONIGHT INTO THURSDAY AS HEIGHTS RISE AND DRYING TAKES PLACE IN THE
MID/UPPER LEVELS. THE PRIMARY CONCERN FOR LATE TONIGHT INTO EARLY
THURSDAY MORNING WILL BE FOG DEVELOPMENT AS SKIES CLEAR OUT IN THE
PRESENCE OF A SHALLOW MOIST BOUNDARY LAYER WITH LIGHT SURFACE WINDS.
WE HAVE INCLUDED THE POSSIBILITY FOR PATCHY AREAS OF DENSE FOG IN THE
HWO/GRAPHICS FOR NOW.
THERE ARE INDICATIONS IN THE GFS THAT LOW-LEVEL MOISTURE CONVERGENCE
WILL INCREASE ALONG THE LINGERING FRONTAL BOUNDARY LATE THURSDAY
AFTERNOON INTO THURSDAY EVENING. MID LEVEL LAPSE RATES WILL BE STEEP
IN NORTHWEST FLOW ALOFT...BUT VERY WEAK FORCING AND QUESTIONABLE MID-
UPPER LEVEL MOISTURE SHOULD MAKE CONVECTIVE PRECIPITATION DIFFICULT
TO GENERATE. HAVE INTRODUCED SLIGHT THUNDERSTORM CHANCES FOR NOW
GIVEN EXPLICIT TSTM DEVELOPMENT IN SOME OF THE WRF GUIDANCE. /EC/
FRIDAY THROUGH WEDNESDAY...THE AIR MASS WILL DRY AND COOL SOME FRIDAY
AS HIGH PRESSURE BECOMES MORE ESTABLISHED. UPPER RIDGING WILL REMAIN
IN PLACE SATURDAY WITH WEAK TROUGHING FORECAST TO FLATTEN RIDGING FOR
THE AREA SUNDAY. LOW LEVEL SLY FLOW WILL BE IN PLACE AGAIN BY SUNDAY
BUT THE AIR MASS SHOULD REMAIN RELATIVELY DRY. THE EURO BRINGS
SLIGHTLY STRONGER UPPER TROUGHING TO THE REGION SUNDAY WITH
INCREASING MOISTURE FROM THE NW. ITS ALSO MORE INDICATIVE OF AT LEAST
ISOLATED SHOWERS FOR MONDAY...PRIMARILY IN THE NORTH...DEVELOPING
SURFACE TROUGHING INTO NRN AR AND TN WHILE THE GFS KEEPS THESE
FEATURES FARTHER N. THE DRIER GFS SOLUTION WILL BE FOLLOWED FOR NOW
IN THE LONGER RANGE BUT RAIN CHANCES WILL BE ADDED IF IT BEGINS TO
TREND TOWARD THE SLIGHTLY MORE ACTIVE LOOKING EURO.
COLD AIR ADVECTION WILL BE ONGOING EARLY FRIDAY IN THE WAKE OF THE
SECONDARY BOUNDARY. WILL FOLLOW UNSEASONABLY COOL MEX MOS HIGHS FOR
FRIDAY AFTERNOON...CUTTING MOS HIGHS SLIGHTLY IN THE FAR SOUTH TO
THE MID 80S CONSIDERING THE COOLER LOW LEVEL TEMPS ADVERTISED BY THE
MODELS/FORECAST SOUNDINGS. SIGNIFICANTLY COOLER LOWS ARE FORECAST BY
MEX MOS FOR SATURDAY MORNING...INCLUDING READINGS IN THE MID 40S
OVER MUCH OF THE AREA N OF I-20 AND E OF I-55. HAVE ADJUSTED THESE
SLIGHTLY WARMER MORE IN LINE WITH THE GFS ENSEMBLE AND EURO BUT KEPT
TEMPS IN THE UPPER 40S/NEAR 50 FOR MANY OF THOSE AREAS FOR NOW. A
GRADUAL WARMING TREND BEGINS SATURDAY AFTERNOON WITH A RETURN TO
WARMER TEMPS AND MORE HUMID CONDITIONS FOR SUNDAY INTO EARLY NEXT
WEEK IN LOW LEVEL SLY FLOW. /03/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 65 90 64 83 / 0 14 16 10
MERIDIAN 61 91 61 84 / 4 12 13 4
VICKSBURG 63 90 64 84 / 0 15 16 12
HATTIESBURG 64 89 66 88 / 5 14 15 2
NATCHEZ 66 89 65 83 / 0 17 18 7
GREENVILLE 63 89 63 77 / 0 15 16 12
GREENWOOD 62 88 61 78 / 0 13 14 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/CME/EC/03
000
FXUS64 KJAN 222109
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
409 PM CDT WED MAY 22 2013
.TONIGHT THROUGH THURSDAY NIGHT...
DESTABILIZATION WAS INSUFFICIENT FOR GETTING SUBSTANTIAL
SHOWER/THUNDERSTORM ACTIVITY THIS AFTERNOON IN THE WAKE OF THE
MORNING CONVECIVE SYSTEM. RAIN CHANCES WILL CONTINUE TO DECREASE
TONIGHT INTO THURSDAY AS HEIGHTS RISE AND DRYING TAKES PLACE IN THE
MID/UPPER LEVELS. THE PRIMARY CONCERN FOR LATE TONIGHT INTO EARLY
THURSDAY MORNING WILL BE FOG DEVELOPMENT AS SKIES CLEAR OUT IN THE
PRESENCE OF A SHALLOW MOIST BOUNDARY LAYER WITH LIGHT SURFACE WINDS.
WE HAVE INCLUDED THE POSSIBILITY FOR PATCHY AREAS OF DENSE FOG IN THE
HWO/GRAPHICS FOR NOW.
THERE ARE INDICATIONS IN THE GFS THAT LOW-LEVEL MOISTURE CONVERGENCE
WILL INCREASE ALONG THE LINGERING FRONTAL BOUNDARY LATE THURSDAY
AFTERNOON INTO THURSDAY EVENING. MID LEVEL LAPSE RATES WILL BE STEEP
IN NORTHWEST FLOW ALOFT...BUT VERY WEAK FORCING AND QUESTIONABLE MID-
UPPER LEVEL MOISTURE SHOULD MAKE CONVECTIVE PRECIPITATION DIFFICULT
TO GENERATE. HAVE INTRODUCED SLIGHT THUNDERSTORM CHANCES FOR NOW
GIVEN EXPLICIT TSTM DEVELOPMENT IN SOME OF THE WRF GUIDANCE. /EC/
FRIDAY THROUGH WEDNESDAY...THE AIR MASS WILL DRY AND COOL SOME FRIDAY
AS HIGH PRESSURE BECOMES MORE ESTABLISHED. UPPER RIDGING WILL REMAIN
IN PLACE SATURDAY WITH WEAK TROUGHING FORECAST TO FLATTEN RIDGING FOR
THE AREA SUNDAY. LOW LEVEL SLY FLOW WILL BE IN PLACE AGAIN BY SUNDAY
BUT THE AIR MASS SHOULD REMAIN RELATIVELY DRY. THE EURO BRINGS
SLIGHTLY STRONGER UPPER TROUGHING TO THE REGION SUNDAY WITH
INCREASING MOISTURE FROM THE NW. ITS ALSO MORE INDICATIVE OF AT LEAST
ISOLATED SHOWERS FOR MONDAY...PRIMARILY IN THE NORTH...DEVELOPING
SURFACE TROUGHING INTO NRN AR AND TN WHILE THE GFS KEEPS THESE
FEATURES FARTHER N. THE DRIER GFS SOLUTION WILL BE FOLLOWED FOR NOW
IN THE LONGER RANGE BUT RAIN CHANCES WILL BE ADDED IF IT BEGINS TO
TREND TOWARD THE SLIGHTLY MORE ACTIVE LOOKING EURO.
COLD AIR ADVECTION WILL BE ONGOING EARLY FRIDAY IN THE WAKE OF THE
SECONDARY BOUNDARY. WILL FOLLOW UNSEASONABLY COOL MEX MOS HIGHS FOR
FRIDAY AFTERNOON...CUTTING MOS HIGHS SLIGHTLY IN THE FAR SOUTH TO
THE MID 80S CONSIDERING THE COOLER LOW LEVEL TEMPS ADVERTISED BY THE
MODELS/FORECAST SOUNDINGS. SIGNIFICANTLY COOLER LOWS ARE FORECAST BY
MEX MOS FOR SATURDAY MORNING...INCLUDING READINGS IN THE MID 40S
OVER MUCH OF THE AREA N OF I-20 AND E OF I-55. HAVE ADJUSTED THESE
SLIGHTLY WARMER MORE IN LINE WITH THE GFS ENSEMBLE AND EURO BUT KEPT
TEMPS IN THE UPPER 40S/NEAR 50 FOR MANY OF THOSE AREAS FOR NOW. A
GRADUAL WARMING TREND BEGINS SATURDAY AFTERNOON WITH A RETURN TO
WARMER TEMPS AND MORE HUMID CONDITIONS FOR SUNDAY INTO EARLY NEXT
WEEK IN LOW LEVEL SLY FLOW. /03/
&&
.AVIATION...THERE WILL STILL SOME ISOLATED SHOWERS AND A FEW STORMS
ROUGHLY ALONG AND SOUTHEAST OF THE NATCHEZ TRACE CORRIDOR THROUGH THE
REMAINDER OF THE AFTERNOON. ANY STORMS COULD PRODUCE EXTREMELY
LOCALIZED INSTANCES OF TURBULENCE AND IFR CONDITIONS. CONDITIONS WILL
BE ALMOST ENTIRELY VFR UNTIL LATER TONIGHT. AT THAT POINT LIGHT WINDS
AROUND A BOUNDARY COMING SOUTH INTO THE REGION WILL WORK WITH MOSTLY
CLEAR SKIES AND MOIST GROUND TO PRODUCE PATCHY FOG AND SOME LOW
CLOUDS. CONDITIONS SHOULD BE MVFR TO IFR COME DAWN TOMORROW AT MOST
SITES WITH IFR CONDITIONS MOST LIKELY AT MEI/NMM/PIB/HBG. EXPECT
FLIGHT RESTRICTIONS TOMORROW TO IMPROVE BETWEEN 830 AND 1030 AM.
AFTERWARD TOMORROW SHOULD BE MAINLY VFR. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 64 90 64 83 / 5 14 16 10
MERIDIAN 62 91 61 84 / 7 12 13 4
VICKSBURG 62 90 64 84 / 5 15 16 12
HATTIESBURG 65 89 66 88 / 17 14 15 2
NATCHEZ 66 89 65 83 / 9 17 18 7
GREENVILLE 62 89 63 77 / 4 15 16 12
GREENWOOD 61 88 61 78 / 4 13 14 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/03/BB
000
FXUS64 KJAN 221614
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1114 AM CDT WED MAY 22 2013
.UPDATE...
THE CURRENT WEATHER ANALYSIS FOR THE ARKLAMISS IS COMPLEX BUT
TYPICAL FOR MAY. A CONVECTIVE SYSTEM HAS MOVE SOUTHEAST OF THE
FORECAST AREA AND THE ATMOSPHERE WILL NEED TO UNDERGO SUBSTANTIAL
RECOVERY AND DESTABILIZATION TO PRODUCE ADDITIONAL THUNDERSTORM
ACTIVITY LATE THIS AFTN. THE MOST RECENT GUIDANCE INCLUDING HRRR/NAM
ARE NOT VERY ROBUST WITH CONVECTIVE DEVELOPMENT...BUT THERE ARE SIGNS
OF A DEVELOPING INSTABILITY/MOISTURE CONVERGENCE AXIS UPSTREAM
ALONG/AHEAD OF THE APPROACHING WEAK COLD FRONT AND THIS SHOULD BE
SUFFICIENT FOR SCATTERED STORM DEVELOPMENT. IN THE FORECAST HAVE
REDUCED TSTM CHANCES BASED ON THE TRENDS AND WILL CONSIDER REMOVING
THE STRONG TSTM REFERENCES DEPENDING ON RADAR/OBS TRENDS IN THE
NEXT COUPLE OF HOURS. THE UPDATED AVIATION DISCUSSION IS BELOW. /EC/
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 22 2013/
SHORT TERM...DRIER AND COOLER AIR WILL FILTER INTO OUR AREA TONIGHT
AS THE SHORTWAVES SHIFTS EAST. THE OPS GFS WAS AMONG THE COOLEST
ENSEMBLE MEMBER AND QUITE COOLER THAN THE NAM MOS. HAVE GONE CLOSER
TO GFS MOS ENSEMBLE MEANS FOR LOWS TONIGHT. WL MAINTAIN NORTHWEST
FLOW ALOFT THURSDAY AS UPPER LEVEL RIDGING AMPLIFIES OVER THE CENTRAL
CONUS. MODELS DIFFER ON PCPN DEVELOP OVER OUR AREA WITH THE SREF AND
NAM BRINGING PCPN WHILE GFS AND ECMWF ARE MOSTLY DRY. HAVE INCLUDED
SLIGHT CHANCE POPS ACROSS SOUTHERN HALF OF THE AREA BY AFTERNOON AS
ENOUGH AVAILABLE MOISTURE AND A SUBTLE SHORTWAVE COMBINE WITH DAYTIME
HEATING TO PRODUCE A FEW SHOWERS AND STORMS. SURFACE HIGH PRESSURE
OVER THE GREAT LAKES REGION WILL SPREAD SOUTH INTO OUR AREA AND BRING
COOLER THAN NORMAL MORNING LOWS FOR FRIDAY MORNING. /22/
LONG TERM...FRIDAY THROUGH WEDNESDAY...THE AIR MASS WILL CONTINUE
TO DRY FRIDAY AS HIGH PRESSURE BECOMES MORE ESTABLISHED. UPPER
RIDGING WILL REMAIN IN PLACE SATURDAY WITH WEAK TROUGHING FORECAST
TO FLATTEN RIDGING FOR THE AREA SUNDAY. LOW LEVEL SLY FLOW WILL BE
IN PLACE AGAIN BY SUNDAY BUT THE AIR MASS SHOULD REMAIN RELATIVELY
DRY. THE EURO BRINGS SLIGHTLY STRONGER UPPER TROUGHING TO THE REGION
SUNDAY WITH INCREASING MOISTURE FROM THE NW. ITS ALSO MORE
INDICATIVE OF AT LEAST ISOLATED SHOWERS FOR MONDAY...PRIMARILY IN
THE NORTH...DEVELOPING SURFACE TROUGHING INTO NRN AR AND TN WHILE
THE GFS KEEPS THESE FEATURES FARTHER N. THE DRIER GFS SOLUTION WILL
BE FOLLOWED FOR NOW IN THE LONGER RANGE BUT RAIN CHANCES WILL BE
ADDED IF IT BEGINS TO TREND TOWARD THE SLIGHTLY MORE ACTIVE LOOKING
EURO.
COLD AIR ADVECTION WILL BE ONGOING EARLY FRIDAY IN THE WAKE OF THE
SECONDARY BOUNDARY. WILL FOLLOW UNSEASONABLY COOL MEX MOS HIGHS FOR
FRIDAY AFTERNOON...CUTTING MOS HIGHS SLIGHTLY IN THE FAR SOUTH TO
THE MID 80S CONSIDERING THE COOLER LOW LEVEL TEMPS ADVERTISED BY THE
MODELS/FORECAST SOUNDINGS. SIGNIFICANTLY COOLER LOWS ARE FORECAST BY
MEX MOS FOR SATURDAY MORNING...INCLUDING READINGS IN THE MID 40S
OVER MUCH OF THE AREA N OF I-20 AND E OF I-55. HAVE ADJUSTED THESE
SLIGHTLY WARMER MORE IN LINE WITH THE GFS ENSEMBLE AND EURO BUT KEPT
TEMPS IN THE UPPER 40S/NEAR 50 FOR MANY OF THOSE AREAS FOR NOW. A
GRADUAL WARMING TREND BEGINS SATURDAY AFTERNOON WITH A RETURN TO
WARMER TEMPS AND MORE HUMID CONDITIONS FOR SUNDAY INTO EARLY NEXT
WEEK IN LOW LEVEL SLY FLOW. /03/
&&
.AVIATION...STILL EXPECT TEMPORARY IFR CONDITIONS THROUGH MIDDAY
ACROSS PORTIONS OF THE AERODROME...AT GLH/GWO DUE TO LOW CEILINGS
AND AT HBG/PIB DUE TO REDUCED VIS AND LOW CEILINGS ASSOCIATED WITH
SHOWERS AND EMBEDDED TSTORMS. OTHERWISE EXPECT VFR CONDITIONS TO
GENERALLY PREDOMINATE TODAY WITH PERIODIC CLOUD CEILINGS FROM 4 TO
10 KFT. THERE WILL BE THE CHANCE FOR SOME THUNDERSTORM REDEVELOPMENT
DURING THE AFTERNOON...ROUGHLY ALONG AND SOUTHEAST OF THE NATCHEZ
TRACE CORRIDOR. ANY STORMS HERE ARE NOT EXPECTED TO BE SEVERE BUT
COULD PROVIDE VERY LOCALIZED INSTANCES OF TURBULENCE AND IFR
CONDITIONS. A FRONT WILL BE PUSHING SOUTH INTO THE REGION LATER
TODAY THROUGH TONIGHT CAUSING GENERALLY LIGHT AND VARIABLE WINDS TO
BECOME MORE SOLIDLY FROM THE WEST AND NORTHWEST. TONIGHT THERE IS A
DECENT PROBABILITY OF LOW CLOUDS AND FOG GIVING IFR RESTRICTIONS AT
HKS/JAN/NMM/MEI/PIB/HBG. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 84 64 89 63 / 41 4 15 8
MERIDIAN 85 64 90 60 / 47 13 15 5
VICKSBURG 84 66 89 61 / 37 4 15 11
HATTIESBURG 84 66 91 64 / 48 17 19 10
NATCHEZ 85 66 90 65 / 40 4 19 15
GREENVILLE 84 65 88 62 / 22 4 10 10
GREENWOOD 83 62 88 60 / 34 4 10 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/03/22/BB
| 
