Area Forecast Discussion
Issued by NWS Lake Charles, LA
Issued by NWS Lake Charles, LA
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389 FXUS64 KLCH 170951 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 451 AM CDT Mon Jun 17 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE... .SYNOPSIS... Issued at 445 AM CDT Mon Jun 17 2024 Latest IR and WV imagery shows copious tropical moisture streaming northward across the Gulf of Mexico from a disturbance located near the Bay of Campeche. KLCH radar shows a few showers already developing over the coastal waters as well as portions of SW LA early this morning, as energy associated with the system spreads over the NW Gulf. This disturbance will be the main player in our weather through at least midweek, and NHC continues to monitor for possible development of a depression or storm. In the meantime, as moisture increases and deepens over the region, so will shower coverage with the potential for heavy rainfall at times the next few days. At the coast, tide levels have already begun to rise in response to the strengthening east to southeast wind field. A Coastal Flood Advisory was issued for our coastal parishes and county yesterday, but given the potential for some significant flooding, especially along the Jefferson County and western Cameron Parish coastlines, a Coastal Flood Watch has now been issued. 24 && .SHORT TERM... (Today through Wednesday night) Issued at 445 AM CDT Mon Jun 17 2024 The trough/low will continue to take shape today in the Bay of Campeche, and could become the first potential tropical cyclone of the 2024 season. As the system develops, deep southeast to south flow will continue to usher tropical moisture over the region, with PWATs increasing to around 2.2 inches. The combination of this moisture, minimal capping and ascent provided by an inverted trough in the midlevels will allow showers and a few storms to become more numerous across the region. With PWATs already well above the 90th percentile and deep moisture profiles indicated on forecast soundings, any showers or storms will be capable of very efficient rainfall resulting in locally heavy downpours. WPC continues to outline much of the area in a Slight Risk (level 2 out of 4) for excessive rainfall that could lead to localized flooding. CAM guidance suggests some isolated spots could receive 3 to 4 inches of rain today. A slight reprieve from the convection will be possible this evening and overnight as instability weakens with the loss of daytime heating, with nocturnal convection developing overnight and moving toward the coastal areas early Tuesday morning. By Tuesday however, a deeper slug of moisture will spread into the region, with PWATs potentially as high as 2.5 inches (or possibly greater) spreading into SE TX and far SW LA as the midlevel trough approaches the TX coast. The latest WPC QPF has backed off some on storm total rainfall amounts (compared to yesterday morning), with a shift in the higher totals to the southwest. Despite this, efficient warm rain processes will still be in play and would support torrential downpours in any showers or storms that develop. A Moderate Risk (Level 3 out of 4) remains in place for portions of far SW LA into lower SE TX for excessive rainfall. Given the recent shift in higher rainfall totals to the southwest (which is reflected in global model guidance as well), have opted to hold off on issuance of a Flood Watch at this time. While flooding from rainfall may not be quite as widespread as it appeared a few days ago, the risk for coastal flooding remains a strong likelihood as the prolonged and strong east to southeast fetch will bring increased water levels. The latest P-ETSS guidance suggests tide levels could rise to between 2 and 3 FT MHHW at Texas Point and between 1.5 and 2.5 FT MHHW at Calcasieu Pass at times of high tide between Tuesday and Wednesday. While there remains some spread in guidance ensembles, these values remain fairly consistent from yesterday morning. Because of this, have gone ahead and issued a Coastal Flood Watch for the Jefferson County and Cameron/Vermilion Parish coasts. The low pressure system will continue to move slowly west to west northwest from Tuesday into Wednesday, approaching the coast of NE Mexico Wednesday night. The bulk of the moisture and energy associated with the system will shift westward into TX, with slightly drier air beginning to filter into the region from the east. Another day of scattered to numerous showers and storms is expected on Wednesday, and the excessive rainfall outlook for Day 3 continues to show at least a Slight Risk for portions of SE TX, with a Marginal Risk extending into SW LA. During this timeframe, daytime temperatures will be cooler than normal thanks to widespread clouds and showers, and temperatures on Tuesday could struggle to reach the middle 80s. 24 && .LONG TERM... (Thursday through Monday) Issued at 445 AM CDT Mon Jun 17 2024 Gulf of Mexico disturbance and its associated large envelop of moisture expected to be well inland Mexico/Texas by Thursday morning, as the large mid to upper level ridge of high pressure builds over the Gulf and Southeastern U.S. states. Lingering moisture will still be available for scattered showers and thunderstorms along and south of the I-10 corridor through Saturday, with the best chances across the coastal waters. With the ridge of high pressure nearly overhead, afternoon temperatures in the lower 90s expected for Thursday, and mid 90s for Friday and Saturday. Lows in the lower to mid 70s. Sunday and Monday a little less confidence in the precipitation forecast, with the lingering Gulf moisture possibly moving northward as the mid to upper level ridge weakens and a weak broad mid to upper level trough prevails over the Central U.S. Blended guidance shows 30-50% inland for Sunday, and 40-60% for Monday, mainly during the afternoons. Highs in the lower to mid 90s, and lows in the mid to upper 70s. 08/DML && .AVIATION... (06Z TAFS) Issued at 1105 PM CDT Sun Jun 16 2024 A thunderstorm is located near LCH otherwise conditions are VFR across the region. The next round of showers will being near sunrise as showers move onshore. Rainfall will be persistent with occasional thunder. Other than convection conditions will be VFR across the region with south winds. && .MARINE... Issued at 445 AM CDT Mon Jun 17 2024 A tropical disturbance in the southwestern Gulf of Mexico will gradually move west-northwest toward the northeast Mexico coast through Wednesday. Deep moisture will be associated with this system that will bring widespread shower and isolated thunderstorm activity. A strengthening gradient between the disturbance and high pressure to the northeast will generate moderate to strong east to southeast winds through mid week. The prolonged fetch will allow for a significant increase in wave heights and swells, as well as an increased risk for coastal flooding. Small Craft Advisories are in effect across the coastal waters. Offshore seas between 10 to possibly 15 feet will be possible from Tuesday into Wednesday, with occasional gusts to gale force. Mariners are encouraged to monitor the latest forecasts. 24 && .PRELIMINARY POINT TEMPS/POPS... AEX 87 72 84 72 / 80 30 50 20 LCH 85 74 82 74 / 80 30 80 50 LFT 87 76 84 76 / 90 40 70 30 BPT 88 76 84 75 / 80 40 80 60 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...Coastal Flood Watch through Wednesday evening for LAZ073. Coastal Flood Watch from this evening through Wednesday evening for LAZ074-252. Coastal Flood Advisory from 7 PM this evening to 7 PM CDT Wednesday for LAZ253-254. TX...Coastal Flood Watch through Wednesday evening for TXZ615. GM...Small Craft Advisory from 1 PM this afternoon to 7 AM CDT Thursday for GMZ450-452-455-470-472-475. && $$ SHORT TERM...24 LONG TERM....08 AVIATION...14