186 FXUS64 KLCH 100356 AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 956 PM CST WED MAR 9 2016 .UPDATE... ALL HAZARDS REMAIN UNCHANGED THIS EVENING...AND ONLY MINOR CHANGES TO THE GRIDS...MAINLY POP/WX/TEMP BASED ON LATEST RADAR TRENDS AND SHORT TERM GUIDANCE. SERIOUS FLASH FLOODING OCCURRING ACROSS PORTIONS OF UPPER SOUTHEAST TEXAS INTO WEST CENTRAL LOUISIANA...WITH JASPER COUNTY...NEWTON COUNTY...AND VERNON PARISH TAKING THE BRUNT OF IT. LIKELIHOOD THAT FLASH FLOOD WARNINGS WILL BE EXTENDED BEYOND THE CURRENT EXPIRATION TIMES. LOW LEVEL JET CONTINUES TO TAKE COPIOUS AMOUNTS OF GULF MOISTURE (PRECIPITABLE WATER NEAR 2 INCHES AND MEAN RH OVER 85 PERCENT FROM 10/00Z KLCH UPPER AIR SOUNDING) AND RIDES IT OVER A NEARLY STATIONARY SURFACE BOUNDARY FROM JUST WEST OF ALEXANDRIA TO JUST NORTHWEST OF BEAUMONT. WEST END OF THE BOUNDARY WAFFLED A LITTLE BACK TO THE NORTH OVER THE PAST HOUR...LESSENING THE SHORT TERM HEAVY RAIN THREAT FOR SOUTHERN AND MIDDLE PORTIONS OF JEFFERSON AND ORANGE COUNTIES. WILL KEEP HIGH POPS FOR SOUTHWEST LOUISIANA...AS RADAR IS SHOWING A BAND BEGINNING TO DEVELOP BETWEEN LAKE CHARLES AND JENNINGS UP THROUGH ALLEN PARISH INTO RAPIDES. THIS IS ON THE EDGE OF MSAS ANALYSIS OF STRONG SURFACE MOISTURE CONVERGENCE...AND THIS AREA MAY VERY WELL FILL IN AND TRAIN AS NOCTURNAL JET PREVAILS...AND WILL HAVE TO BE WATCHED CLOSELY. ALSO...SHORT TERM GUIDANCE IS STILL WANTING TO DEVELOP A MCS LIKE FEATURE OVER SOUTHEAST TEXAS DURING THE OVERNIGHT AND PUSH EVERYTHING OFF TO THE EAST DURING EARLY THURSDAY...ALTHOUGH CONFIDENCE IS NOT GREAT IN THAT HAPPENING AND PORTIONS OF SOUTHWEST LOUISIANA AND ACADIANA MAY MISS OUT ON ANY SIGNIFICANT ACTIVITY UNTIL DAYTIME THURSDAY. RUA && .PREV DISCUSSION... /ISSUED 643 PM CST WED MAR 9 2016/ DISCUSSION... FOR THE 00Z TAF PACKAGE. AVIATION... EXTENSIVE AREA OF RAIN WITH EMBEDDED THUNDER NOW OVER EAST TEXAS AND INTO WEST CENTRAL LA...WITH MORE SCATTERED SHOWER ACTIVITY FARTHER EAST. EARLIER EASTWARD PROPAGATION OF THIS MAIN CONVECTIVE BAND APPEARS TO HAVE SLOWED NEAR A FT POLK TO PORT ARTHUR LINE. TAF PACKAGE WAS CONSTRUCTED WITH AT LEAST SOME EASTWARD PROGRESSION IN MIND THIS EVENING AND OVERNIGHT...AS INDICATED BY MOST MODEL GUIDANCE. THIS MAY HAVE TO BE RE- EVALUATED IN TERMS OF TSRA TIMING PENDING RADAR TRENDS. IN ANY CASE...MVFR TO GENERALLY PREVAIL AWAY FROM CONVECTION...WITH ELEVATED AND AT TIMES GUSTY SOUTH WINDS...ESPECIALLY KLCH-KLFT- KARA. IFR TO LIFR IN TORRENTIAL RAINFALL ASSOCIATED WITH CONVECTION. 13 PREV DISCUSSION... /ISSUED 442 PM CST WED MAR 9 2016/ SYNOPSIS... REGIONAL RADAR MOSAIC SHOWS A LARGE AREA OF SHOWERS AND STORMS EXTENDING FM ARK SSW INTO NRN LA/ERN TX DOWN TOWARD FAR S TX. WHILE THIS LARGER AREA OF STORMS HAS BEEN ONGOING DUE TO DEEP UPR LOW OVER NWRN MEXICO...THE ACTIVITY ACRS SE TX INTO WRN/CNTL LA HAS BEEN AIDED BY LIFT ASSOCIATED WITH A QUASI-STATIONARY FRONTAL BOUNDARY ALONG A MLU-JAS-IAH LINE. RAINFALL AMOUNTS OVER THE PAST 6 HOURS HAVE RANGED FM 1.5 TO NEARLY 4 INCHES ACRS NRN JASPER AND NEWTON COUNTIES AND NWRN VERNON PARISH...WHILE STORM TOTALS SINCE YESTERDAY ARE NEARLY 7.5 INCHES ACRS THE SAME REGION. THE OVERALL SVR THREAT HAS BEEN LIMITED TODAY THANKS TO LIMITED INSTABILITY AND WEAK LAPSE RATES ALOFT...ALTHOUGH SHEAR HAS BEEN ADEQUATE TO PRODUCE A FEW STORMS WITH ROTATION TODAY. AS WAS THE CASE YESTERDAY...VERY STRONG AND GUSTY WINDS HAVE BEEN OCCURRING ACRS THE AREA TODAY DUE TO A VERY TIGHT PRES GRADIENT OVER THE REGION BETWEEN LOW PRES OVER TX AND HIGH PRES OFF THE SE COAST. SUSTAINED WINDS TODAY AT SEVERAL SITES HAVE BEEN RUNNING BETWEEN 20 AND 30 MPH WITH GUSTS MOSTLY BETWEEN 30 AND 40 MPH ALTHOUGH A FEW LOCATIONS HAVE AGAIN SEEN GUSTS TO AROUND 45 MPH AT TIMES. DISCUSSION... PERSISTENT VIGOROUS UPR LOW AND ASSOCIATED SFC LOW PRES/FRONT WILL MAINTAIN THE THREAT OF HEAVY RAINFALL THROUGH THE NEXT FEW DAYS AS THE SYSTEM MEANDERS OVER THE REGION. CURRENT HAZARDS...FLOOD WATCH...WIND ADVISORY AND COASTAL FLOOD WARNING...REMAIN IN EFFECT THROUGH THURSDAY. THE PRIMARY ISSUE FOR THIS FCST PKG WILL BE QPF OVERNIGHT INTO THURSDAY. AT THIS TIME...LEANED TOWARD LATEST HRRR TRENDS WHICH SEEM TO HAVE DONE A DECENT JOB ON PLACEMENT OF CONVECTION/HIGHER QPF. THUS...KEPT HIGHEST RAINFALL TOTALS ACRS INTERIOR SE TX THIS EVENING...WHICH LOOKS TO BE IN LINE WITH RECENT RADAR TRENDS...AS WELL AS OVERNIGHT. WHILE THE OVERALL QPF TOTALS FM 00Z-12Z INDICATE ABOUT 3 TO 5 INCHES ACRS SE TX...TRAINING OF STORMS WILL SET UP THE POSSIBILITY OF MUCH HIGHER LOCALIZED AMOUNTS. AS IS ALSO THE CASE IN THESE SITUATIONS...IDENTIFYING THE SPECIFIC LOCATIONS THAT WILL SEE THE GREATEST AMOUNTS WILL BE DEPENDENT ON CONVECTIVE FORCING AND THE TRANSLATION OF ENERGY ALOFT...WHICH CAN IMPACT WHERE ACTUAL RAINBANDS AND TRAINING STORMS SET UP. THIS CAN RESULT IN HEAVIER RAINS OCCURRING A LITTLE FURTHER EAST ACRS THE WRN LA PARISHES OR WEST ACRS JEFFERSON/HARDIN/TYLER OR EVEN ACRS MULTIPLE AREAS. FOR THURSDAY...THE HEAVIEST RAINFALL LOOKS TO BEGIN SHIFTING EAST...PLACING MORE OF CNTL LA AND THE ACADIANA REGION UNDER THE HEAVIEST BULLS-EYE. THE FLOOD WATCH MAY NEED TO BE EXTENDED OVER THE EASTERN ZONES INTO FRIDAY SHOULD BANDS OF RAIN BEGIN TO TRAIN OVER THESE AREAS. OTHERWISE...EXPECT RAIN CHCS TO GRADUALLY DIMINISH...BUT NOT QUITE COME TO AN END THROUGH SATURDAY UNTIL THE LARGE UPR LOW WEAKENS AND LIFTS OUT. A SECONDARY SHORTWAVE IS PROGGED TO SWING THROUGH THE REGION SUNDAY INTO MONDAY...BRINGING ANOTHER SMALL CHC FOR RAIN TO THE EXTREME NRN ZONES. THINGS THEN LOOK TO BEGIN DRYING OUT BY EARLY NEXT WEEK. MARINE... A TIGHT PRES GRADIENT ACROSS THE REGION WILL MAINTAIN AN EXTENDED FETCH OF STRONG SLY WINDS WITH EXTREMELY ROUGH SEAS THROUGH THURSDAY. ADDITIONALLY...EXTENSIVE SHOWER AND TSTM ACTIVITY CAN BE EXPECTED WITH STRONG TO SVR TSTMS POSSIBLE. WINDS WILL BEGIN TO DIMINISH LATE THURSDAY...WITH THE GALE WARNINGS LOWERING TO SMALL CRAFT ADVISORIES. WINDS WILL CONTINUE TO WEAKEN...GRADUALLY BCMG MORE SWLY AS THE SFC LOW LIFTS NE. && .PRELIMINARY POINT TEMPS/POPS... AEX 69 77 67 74 / 90 100 90 80 LCH 70 77 65 74 / 80 90 80 70 LFT 72 76 67 74 / 70 100 90 80 BPT 69 77 64 76 / 90 90 80 60 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...COASTAL FLOOD WARNING UNTIL 6 AM CST THURSDAY FOR LAZ052>055-073- 074. FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR LAZ028-029- 031>033-042>045-052>055-074. WIND ADVISORY UNTIL NOON CST THURSDAY FOR LAZ033-041>045-052>055- 073-074. FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR LAZ027-030-041- 073. COASTAL FLOOD ADVISORY UNTIL 6 AM CST THURSDAY FOR LAZ041. TX...COASTAL FLOOD WARNING UNTIL 6 AM CST THURSDAY FOR TXZ215. WIND ADVISORY UNTIL NOON CST THURSDAY FOR TXZ215-216. FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR TXZ180-201-215- 216-259>262. COASTAL FLOOD ADVISORY UNTIL 6 AM CST THURSDAY FOR TXZ216. GM...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM CST THURSDAY FOR GMZ475. GALE WARNING UNTIL 6 AM CST THURSDAY FOR GMZ472-475. SMALL CRAFT ADVISORY UNTIL NOON CST THURSDAY FOR GMZ450-452-470. SMALL CRAFT ADVISORY FROM 6 AM TO NOON CST THURSDAY FOR GMZ472. SMALL CRAFT ADVISORY UNTIL 6 AM CST THURSDAY FOR GMZ430-432-435. SMALL CRAFT EXERCISE CAUTION FROM 6 AM CST THURSDAY THROUGH THURSDAY MORNING FOR GMZ430-432. SMALL CRAFT ADVISORY UNTIL 6 PM CST THURSDAY FOR GMZ455. SMALL CRAFT EXERCISE CAUTION FROM 6 AM CST THURSDAY THROUGH THURSDAY AFTERNOON FOR GMZ435. && $$ PUBLIC...07