SW Louisiana Forecast Discussion...The much advertised prolonged rain event is underway. It came in spurts at first during the day today with light rain commencing before noon, and off and on throughout the afternoon. This was just a harbinger of things to come. The same pattern that we have seen many times so far this season is at it again. As of this writing, a solid shield of rain encompasses the entire forecast area. It was rather raw throughout the day as well with temperatures right on track of the official forecast in the mid 50s. Rain cooled air dropped the temperatures into the 40s as some wet bulbing occurred this morning with relatively dry air in place at the surface. Rain will continue all night as the ingredients come together to produce this prolonged rain event and heavy rain and flooding threat.
A strong short wave embedded in the active Subtropical Jet Stream, and rounding the base of a Western trough is moving Eastward tonight, and this feature combined with the STJ energy has generated cyclogenesis in the Western Gulf. The low will slowly track up the coast overnight through Thursday, and the rain will be unrelenting. Rain will be increasing in intensity throughout the night as isentropic lift increases with the advancement of the low. Rain will be heavy at times after midnight through Thursday. The greatest risk for flooding will occur along and South of I-10 where storm totals could exceed 4" in some locations, but the average rainfall amounts will be 2-3". Lighter amounts will occur across the Northern portion of the forecast area, but even they should see an inch of rain. A Flood Watch has been issued for a portion of the forecast area...roughly along and SE of a line from Cameron to Opelousas. This includes Cameron, Vermilion, Jeff Davis, Acadia, Lafayette, St. Landry, St. Martin, & Iberia Parishes. The rest of the forecast area isn't currently under a Flood Watch at this time, but this could certainly change overnight depending on where the heavy rain axis sets up. Precipitation chances are maxed out through Thursday, and this system will only slowly move out of the area. A warm front trailing from the Western Gulf low will also be heading Northward overnight and Thursday. The final track of the low is still a bit uncertain with some model discrepancy noted, but it's final track will ultimately dictate where the heaviest rain, and potential for severe weather will be. Severe weather doesn't appear to be an issue across the forecast area at this point, as the surface low should remain over the nearshore waters before pushing into SE Louisiana. The pressure gradient will also be a key factor in the forecast. Winds will increase in response to a strengthening Gulf low, and speeds will exceed 25 mph at times late tonight and Thursday. The primary direction will be from the NE around the circulation of the low. The track of the low will result in the forecast area remaining in the cool sector, thus helping to limit severe weather as I previously mentioned. However, it should be noted that instability will increase late tonight through Thursday morning, and some thunderstorms will be possible. The low will make its closest approach to the forecast area between sunrise and noon on Thursday, and this is when the heaviest rain should occur. It is hard to pinpoint exactly who will get the heaviest rain, but it should be somewhere in the Southern half of the forecast area. While rainfall totals have been below normal for the year so far, it has been an incredibly wet fall and winter thus far, and this combined with widespread dead vegetation across the area will aid in the flooding threat. It will remain quite raw as well when you throw temperatures into the equation. Overnight lows tonight will be in the mid 40s, while Thursday highs only top out in the lower 50s at best. It is very common in this pattern to see a very small diurnal range when widespread clouds and showers are expected. Conditions will be monitored for further revisions for flood watches, etc. Rain will only slowly taper off Thursday, and I would expect to keep raining past the evening rush hour. However, the heaviest rain should taper off by then with a return of mostly light rain by that time as the low pulls away. It isn't entirely out of the realm of possibility that some locations may receive more than 5" of rain between tonight and tomorrow night.
Conditions improve some for Thursday night as the "Cajun Nor'Easter" pulls away. Rain chances will continue for the overnight hours as some wrap-around moisture will be present. Mostly light rain and/or intermittent drizzle is expected. It will seasonably cool as well with lows dropping into the mid 40s once again. The chance for some light rain and drizzle will greet us on Friday, but conditions will continue to improve as drier air filters in thanks to an area of high pressure building into the region. I will keep rain chances confined to the morning hours at this time, however, cloudy skies should hang tough throughout the day Friday with the presence of a pesky low-level stratus deck. One reason why it will take the rain so long to vacate the area is the driving force behind this system, and that is a cut off low over the Desert SW. This low will not push through the area until Friday. There really has been much change in the forecast philosophy since Monday's forecast package for this same time frame. Models are in fair agreement on this solution. There really isn't a cold front associated with this Gulf storm, however, some colder air will filter into the region in its wake thanks to a Northerly flow at the surface. This will help to pull down some colder air over the snow covered ground to our North. However, it won't be terribly cold, but it will certainly be coat weather. It will quite damp as well. The wrap-around moisture will keep humidity values high and leave plenty of boundary layer moisture in place for a good portion of Friday. High pressure will build into the region from the Red River Valley by Friday night, and skies will clear. The high looks like it will be strong enough to give the Subtropical Jet Stream a temporary nudge Southward into the Gulf. Thus, I expect that once skies clear Friday night, they will stay that way through Saturday and into Super Bowl Sunday. Temperatures will remain on the chilly side, with an overnight low in the upper 30s to near 40 for Saturday morning while Sunday morning will be colder with high pressure right overhead at that time. Minimum temperatures will be at or below freezing across the Northern half of the forecast area with 30s area wide. A low of around 34 seems feasible for the Lake Charles area. Saturday maximums should be in the mid 50s, while the maximum for Sunday should be in the mid 50s as well. Lower 60s are normal for the first week of February.
There's some big ball game on Sunday, right? The Super Bowl of course, featuring our New Orleans Saints vs. the Indianapolis Colts. The weather here for the big day looks great, but the high clouds will likely return during the day as the STJ remains active, and we will have to contend with that on Monday.High temperatures should be in the low to mid 50s. Any plans you may have for Super Bowl Sunday. As for the game site itself in Miami, the weather looks great there too with clear skies and pleasant temperatures in the 60s. The Colts will need to watch out for a strong Brees, Shockey waves, and Colston fronts. There will be a nip in the air for Super Bowl Sunday, so perhaps some Colt Gumbo is in order. Clouds will begin to increase Sunday night as the active Subtropical Jet Stream continues. Rain chances will return to the forecast on Monday ahead of a strong cold front. The same pattern will repeat itself once again with yet another Gulf low expected. Rain chances will be back into the likely category by Monday afternoon. A return flow of Gulf air is expected as well out ahead of the approaching cold front. Therefore, a decent warm up is expected. Highs should reach and possibly exceed 60. No severe weather is expected Monday, but some thunderstorms certainly can't be ruled out with instability in place. Monday morning lows should be in the upper 30s to lower 40s. This system should be a much faster mover than the current one. Rainfall amounts should be far less than we expect for the next 24 hours. The surface low should track much further to the South than the current one, thus limiting the heavy rain threat. The best chance of rain should come overnight Monday as the strong front works through. There will be some rain around at this time, than could possibly hamper some Saints Super Bowl celebrations, though I doubt even some rain will dampen anyone's spirit.
The rain chances will continue into Tuesday before much improved weather is noted. This will be a fairly strong front with origins from Canada. It will mark a pattern shift for the forecast area as already unseasonably cool weather is replaced with much below normal temperatures. Rain chances and windy conditions will be the dominant weather features for Tuesday behind the front. Rain will be possible mainly during the morning as CAA takes over. Temperatures will likely stay in the 40s throughout the day. Clearing will occur late as high pressure builds in. This will pave the way for freezing temperatures area wide by the end of the forecast period on day 7. Morning lows should be down into the mid 20s to near freezing across the area under clear skies. An offshore flow will be present with Canadian high pressure building in. Afternoon highs on day 7 should remain well below normal with 40s expected. It will be quite cold on Tuesday evening for the big Saints parade in New Orleans, but it should be dry. Wind chills will be a factor on Tuesday afternoon and Tuesday night as the pressure gradient creates strong winds over the area. You can expect wind chills well down into the 20s by Tuesday night. Winter is certainly not over, and we will be reminded of that in the wake of Monday night's front. Beyond the forecast period, it looks to remain cold. The active El Nino pattern will continue with another wet system in here over Valentine's and Mardi Gras weekend. It will remain on the cool side with highs in the 40s and 50s and lows in the 30s and 40s. during this time. Specific timing and other vital information regarding these type of systems will be become available as the time frame of interest gets closer, but as I always say you have to watch for trends. The established trend that we've seen for much of the fall and winter so far looks to be in full force beyond the forecast period, so we'll go with that for now. Stay tuned!
Preliminary Numbers & Zone Forecast:
LCH 45/50 43/51 39/56 100 100 40 30 0 0
LFT 44/52 42/50 38/55 100 100 50 30 0 0
BPT 45/49 44/53 40/56 100 100 40 30 0 0
AEX 41/45 40/48 35/53 100 100 40 30 0 0
POE 41/45 40/48 36/54 100 100 40 30 0 0
ARA 46/55 45/53 40/55 100 100 50 30 0 0
*Lake Wind Advisory in effect through Thursday.*
*Flood Watch in effect through Thursday for Cameron, Jeff Davis, Acadia, Lafayette, Vermilion, St. Landry, St. Martin, & Iberia Parishes.*
Tonight..Rain and a few thunderstorms. Rain heavy at times. Low 45. NE 15-20 mph and gusty. Chance of rain 100%.
Thursday...Rain and a few thunderstorms. Rain heavy at times. Localized flooding possible. 2-4" of rain expected. Windy. High 50. NNE wind 20-25 mph and gusty. Chance of rain 100%.
Thursday Night...Mostly Cloudy with a 40% chance of rain. Low 43. North wind 15 mph.
Friday...Continued Mostly Cloudy with a 30% chance of rain. High 51. North wind 10-15 mph.
Friday Night...Decreasing Cloudiness and Cold. Becoming Clear by Midnight. Low 39. North wind 5-10 mph.
Saturday...Sunny. High 56. North wind 10 mph.
Thursday 2/4/10 Daily Planner
7a.m.
Weather: Rain
Temp: 45
Chance of Rain: 100%
Wind: NE 17
Noon
Weather: Rain
Temp: 48
Chance of Rain: 100%
Wind: NE 21
5p.m.
Weather: Light Rain
Temp: 49
Chance of Rain: 70%
Wind: N 18
Drew's 7 Day Outlook for Lake Charles & Vicinity
Thursday
2-4-10
Low: 45
High: 50
Precip: 100%
Wind: NNE 20-25
Friday
2-5-10
Low: 43
High: 51
Precip: 30%
Wind: N 10-15
Saturday
2-6-10
Low: 39
High: 56
Precip: 0%
Wind: N 10
Sunday
2-7-10
Super Bowl
Low: 34
High: 56
Precip: 0%
Wind: NE 10
Monday
2-8-10
Low: 42
High: 59
Precip: 60%
Wind: SE/NNW 15-20
Tuesday
2-9-10
Low: 43
High: 47
Precip: 40%
Wind: NNW 15-20
Wednesday
2-10-10
Low: 28
High: 45
Precip: 0%
Wind: N 10-15
W.C.: 20-30
...Marine Forecast...
*Small Craft Advisory.*
Tonight...East winds 25 to 30 knots. Seas 5 to 6 feet building to 6 to 8 feet after midnight. Rain and isolated thunderstorms.
Thursday...Southeast winds 15 to 25 knots becoming east 15 to 20 knots in the afternoon. Seas 6 to 8 feet subsiding to 4 to 6 feet in the afternoon. Rain and isolated thunderstorms.
Thursday Night...Northwest winds 10 to 15 knots. Seas 3 to 5 feet subsiding to 2 to 4 feet after midnight. A chance of rain.
Friday...Northwest winds 10 to 15 knots. Seas 1 to 3 feet subsiding to 1 to 2 feet in the afternoon.
Friday Night...North winds 10 to 15 knots. Seas 1 to 2 feet.
Saturday...Northeast winds 10 to 15 knots. Seas 1 to 2 feet.
Good night and God bless!
-DM-
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