882
FXUS64 KLIX 202101
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
401 PM CDT MON MAY 20 2013

.SYNOPSIS...
LATEST SURFACE ANALYSIS SHOWED A SURFACE RIDGE OF HIGH PRESSURE
FROM THE MID ATLANTIC STATES TO THE NORTHEAST GULF. SOUTHERLY FLOW
WAS LOCATED OVER THE LOWER AND MID MISSISSIPPI VALLEY WITH
DEWPOINT TEMPERATURES IN THE 69 TO 73 DEGREE RANGE FROM THE
LOUISIANA COAST NORTH TO INTERSTATE 40. A DEEP SURFACE LOW OVER
WEST MINNESOTA WITH A BOUNDARY SOUTH TO CENTRAL OKLAHOMA TO THE
WEST TEXAS. UPPER AIR ANALYSIS SHOWED A LARGE CYCLONIC
CIRCULATION CENTERED OVER WESTERN MINNESOTA WITH THE MAIN TRAILING
AXIS SOUTHWEST TO NORTHERN NEW MEXICO. THIS MORNING SOUNDING SHOWED
A WARM NOSE OR INVERSION FROM 840 TO 770MB AND SURF TEMPS IN THE
MID 90S WILL LIKELY BREAK THE CAP IN PLACE. ISOTACH ANALYSIS AT
250MB SHOWED THE JET MAX OF 90 KNOTS AT THE BASE AND FRONT SIDE OF
THE TROUGH AND SUB-JET OF 60 KNOTS FROM SOUTH TEXAS TO SOUTH
CENTRAL GULF.

&&

.DISCUSSION...
THE SURFACE LOW AND THE MAIN UPPER LEVEL LOW WILL BECOME MORE
VERTICALLY STACKED THROUGH TUESDAY. THIS FEATURE WILL SLOW THE
PROGRESSION OF THE SURFACE FRONT INTO THE DEEP SOUTH THIS WEEK.
THIS WILL RESULT IN SOME SLOWING AND STALLING OF THE SURFACE COLD
FRONT. HOWEVER...UPPER LEVEL DISTURBANCE AT THE BASE OF THE MAIN
TROUGH WILL EJECT NORTHEAST ACROSS TEXAS PANHANDLE ON TUESDAY AND
NORTH MISSISSIPPI BY WEDNESDAY MORNING. MOISTURE AXIS WILL POOL
ALONG THE ASSOCIATED AXIS FROM WEST TENNESSEE TO SOUTHEAST TEXAS
WEDNESDAY MORNING...AFFECTING NORTHWEST ZONES NORTH OF BTR AND
SOUTHWEST MS....ERGO WILL MAINTAIN SLIGHT CHANCE TO CHANCE POPS.

ASSOCIATED SHORT WAVE WILL MOVE EAST WITH MOISTURE POOLING OVER
THE NORTH HALF OF THE FORECAST AREA WEDNESDAY MORNING. DEEP SOUTH
TO SOUTHWEST FLOW OF 20 TO 25 KNOTS FROM SURF TO 700MB AND WEST
FLOW AND WEST FLOW OF 35 KNOTS FROM 650MB TO 300MB...PRODUCING
SOME DIRECTIONAL SHEAR OR A HELICITY OF AROUND 100 M/S WEDNESDAY
MORNING ACCORDING GFS AND NAM. HOWEVER...CAPE VALUES OF 2500 J/KG
BEFORE THE SHORT WAVE PASSAGE...WITH SIGNIFICANT CAPE VALUES ABOVE
-20C. THEREFORE...STRONG STORMS ARE POSSIBLE WEDNESDAY MORNING
STRONG WINDS AND HAIL...HAVE MAINTAINED STRONG AND LATER PACKAGES
MAY USE STRONGER WORDING WITH HAIL FOR WEDNESDAY MORNING.

SHORT WAVE WILL PUSH EAST AND LEAVE MOISTURE...THUS MAINTAIN A
GOOD CHANCE OF RAIN ON THURSDAY. MAIN UPPER LEVEL LOW/TROUGH WILL
DIG OVER THE EAST CONUS WITH A NORTHWEST FLOW DEVELOPING OVER MID
SOUTH AND LOWER MISSISSIPPI VALLEY EARLY FRIDAY AND DRIVE A
SURFACE FRONT THROUGH LAND AND MARINE AREA FRIDAY MORNING. FRONT
WILL PUSH THROUGH FRIDAY AND CREATE A DRY AND SLIGHTLY COOL
WEEKEND

&&

.AVIATION...
LITTLE CHANGE IN THE PATTERN OVER THE LAST SEVERAL DAYS...AND NOT
MUCH CHANGE ANTICIPATED UNTIL ABOUT WEDNESDAY.

VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND EVENING AT
MOST LOCATIONS. HOWEVER...ONCE AGAIN EXPECT AN INVERSION OVERNIGHT
TONIGHT WITH LOW STRATUS DEVELOPING GENERALLY AFTER 06Z. CIGS
EXPECTED TO REMAIN IN THE MVFR RANGE...THOUGH A COUPLE HOURS OF IFR
CIGS WILL BE POSSIBLE. EXPECT CONDITIONS TO BEGIN IMPROVING AFTER
15Z.

&&

.MARINE...
RIDGE OF HIGH PRESSURE CENTERED IN THE WESTERN ATLANTIC EXTENDS
INTO THE NORTHEAST GULF OF MEXICO. IT WILL SLOWLY RETREAT EAST
THROUGH WEDNESDAY. THIS WILL KEEP WINDS SOUTHEASTERLY AT 10 TO 15
KNOTS...POSSIBLY A TOUCH ABOVE 15 KNOTS BRIEFLY IN THE FAR WESTERN
WATERS. SEAS THRU THAT PERIOD TO BE MAINLY IN THE 2 FOOT
RANGE...WITH THE EXCEPTION OF THE WESTERN WATERS WITH 3 TO 4 FOOT
WAVES POSSIBLE TONIGHT AND TUESDAY WITH PERSISTENT WINDS NEAR 15
KNOTS.

UPPER LEVEL TROUGH WILL DIG ACROSS THE EASTERN HALF BEGINNING MID
WEEK. THIS WILL BREAK DOWN RIDGE OVER THE GULF COAST AND CAUSE THE
WIND FIELD TO BREAKDOWN. A WEAK FRONTAL BOUNDARY WILL PASS THROUGH
FRIDAY MORNING WITH A WIND SHIFT TO THE NORTH THROUGH MUCH OF THE
WEEKEND. 18

&&

.DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
             MONITORING RIVER FLOODING.

DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN  = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE   = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
         VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
         WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
         TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED    = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
         AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
         SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  71  88  68  85 /  10  10  20  50
BTR  73  89  72  88 /  10  10  20  40
ASD  73  87  70  86 /   0  10  10  30
MSY  74  87  73  86 /  10  10  10  30
GPT  73  83  72  84 /   0  10  10  30
PQL  68  86  68  86 /   0   0  10  30

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&

$$