SW Louisiana Forecast Discussion...The drier air and lower humidity of the past few days is eroding. A couple of weather features are aiding in this process. The frontal boundary which came through last weekend has begun to dissipate, but the biggest player involved in the weather today was a Westward moving Upper Level Low which was mentioned in previous forecast discussions. This upper level low was positioned near the Mississippi River this afternoon in NE LA/Central MS. The cold air aloft associated with this system, combined with daytime heating resulted in shower and thunderstorm activity to develop across parts of the forecast area. Storm initiation was over SE Texas around the backside of the low, and the storms pushed SE in response to a NWly flow aloft in advance of a forthcoming trough. The storms moved into the forecast area around lunch time and progressed ESE through the area through mid-afternoon. Some thunderstorms reached severe limits today, and a severe thunderstorm watch was in effect for much of the forecast area for the afternoon hours.
The strongest storms were NW and NE of Lake Charles. Hail-bearing storms occurred in fact, this is rare across the area for August. The hail was caused by the cold air aloft generated by the upper level low. Some hail sizes reported with the storms either last night or today include golf-ball sized and egg-sized. Some smaller reports of hail occurred here in Calcasieu Parish with penny to nickel sized hail around Vinton. The storms weakened considerably as they moved into Lake Charles, and had fallen below severe limits by that time. Temperatures today were close to normal for August, and this trend will continue for the remainder of the work week, but with increased humidity.
All is quiet across the area tonight, but some isolated shower or thunderstorm activity can't be ruled out before morning with the upper level low in place just to our North. A repeat is in store for Thursday with said upper level low in place. I expect about average coverage of showers and thunderstorms primarily from lunch time onward, however, with sufficient cold air aloft once again, a few storms could once again approach severe limits. The upper level low should weaken a bit, so the storms may not be as strong, but it certainly can't be ruled out that there might be a hail-bearer or two once again. Expect afternoon maximums right around 90.
The upper level low will not move much further West as it will bump into winds out ahead of an advancing trough. This trough will cause the ULL to be deflected back to the East. This should happen during the day Thursday, and it should be out of the area by Thursday night. A quiet period is in store Thursday night with just lots of humidity expected. Going into Friday, rain chances remain with us as the trough advances closer to the forecast area. This is a similar pattern to what we had a week ago. The cold front associated with the aforementioned trough will keep rain chances in the forecast, and help to increase them to above normal levels for Friday. Better chances are expected later in the day as the front moves in. The front may not actually clear the area until overnight Friday into Saturday, hence, rain chances will remain in the forecast for these periods as well. Activity should remain on a scattered basis, however, and I don't expect a wash out by any means. Temperatures will remain seasonable through this period as well.
If we play our cards right, this front, like its predecessor will advance into the coastal waters over the weekend. This will usher in drier air beginning during the day Saturday. It will be more noticeable by Sunday, and will remain in place for the remainder of this forecast period. Not much cooling is expected with this front, but readings should be similar to that we've seen the first part of this week. It is still August, and will be going into early September, and the main effect from any front we are lucky enough to get this time of year will be drier air. Rain chances are absent from the Sunday through Wednesday periods at this time with temperatures trending a few degrees cooler for the same period.
Tropics:
The 4th named storm of the season developed today. This is the same area of disturbed weather I highlighted in my last update. Tropical Storm Danny formed around 10a.m. after Hurricane Hunters finally found a closed low-level circulation. The storm remains somewhat disorganized tonight with an exposed low-level center, and a reconfiguring of the actual LLC is possible through tomorrow as the storm tries to find its identity. Danny is a 50 mph Tropical Storm at this time, and is expected to strengthen slowly for the next couple of days. With a trough advancing across the country, Danny is not forecasted to be a threat to the Gulf of Mexico, but it looks like it will be a close call for the East Coast. Danny could strengthen into a hurricane by this weekend. It is too early to say if Danny will actually make a U.S. landfall, but everyone along the East coast especially from North Carolina to Maine should keep a close eye on Danny. Danny is likely to be steered by a couple of mechanisms over the Atlantic. Danny is moving NW tonight around the periphery of the persistent Atlantic ridge, but will turn more to the North by Friday afternoon as it feels the effects of the ULL currently over our area, and advancing trough. The current advisory on Danny follows:
Tropical Storm Danny
26.0N
71.6W
This is about 370 miles ENE of Nassau, Bahamas and 675 miles SSE of Cape Hatteras, NC.
Winds: 50 mph with higher gusts. Slow strengthening is expected over the next couple of days, and Danny could become a hurricane this weekend. Tropical Storm force winds currently extend outward to 175 miles from the center.
Moving: NW @ 10 mph. This forward motion is expected through Thursday, with an acceleration in forward speed and turn to the North expected Friday.
Pressure: 29.71" or 1006 mb.
The next advisory will be issued by the National Hurricane Center at 4a.m. Thursday.
Elsewhere in the tropics, a new tropical wave has just emerged off the coast of Africa. A disorganized area of showers and thunderstorms is currently located near the Cape Verde Islands. Slow development of this system is possible through the end of the week. No other tropical storm development is forecast through Friday.
Preliminary Numbers and Zone Forecast:
LCH 70/91 71/90 72/90 20 30 0 40 30 30
LFT 68/91 70/89 71/90 20 30 0 40 40 30
BPT 72/92 73/90 74/91 20 30 0 40 30 20
AEX 66/93 69/92 68/91 20 30 0 50 30 10
POE 67/93 69/92 69/91 20 30 0 50 30 10
ARA 69/91 71/88 73/90 20 30 0 40 40 20
AEX 66/93 69/92 68/91 20 30 0 50 30 10
POE 67/93 69/92 69/91 20 30 0 50 30 10
ARA 69/91 71/88 73/90 20 30 0 40 40 20
Tonight...Partly Cloudy with a 20% chance of showers and thunderstorms after midnight. Low 70. Light South wind.
Thursday...Partly Cloudy with a 30% chance of showers and thunderstorms. High 91. SE wind 10-15 mph.
Thursday Night...Partly Cloudy, becoming Mostly Clear. Low 71. Light South wind.
Friday...Partly to Mostly Cloudy with a 40% chance of showers and thunderstorms especially later in the day. High 90. SE wind 10-15 mph.
Friday Night...Partly to Mostly Cloudy with a 30% chance of showers and thunderstorms. Low 72. SW wind 10 mph.
Saturday...Partly Cloudy with a 20% chance of showers and thunderstorms, mainly during the morning. High 90. SW wind becoming NW 10-15 mph.
7 Day Outlook for Lake Charles & Vicinity
Thursday
8-27-09
70/91/30
Wind: SE 10-15
H.I.: 98-103
U.V.: 11- Very High
Friday
8-28-09
71/90/40
Wind: SE 10-15
H.I.: 100-105
U.V.: 10- High
Saturday
8-29-09
72/90/20
Wind: SW/NW 10-15
H.I.: 93-98
U.V.: 11- Very High
Sunday
8-30-09
69/89/0
Wind: North 5-10
H.I.: 90-95
U.V.: 11- Very High
Monday
8-31-09
68/89/0
Wind: North 5-10
H.I.: 88-93
U.V.: 11- Very High
Tuesday
9-1-09
66/88/0
Wind: NNW 5-10
H.I.: 85-90
U.V.: 11- Very High
Wednesday
9-2-09
64/89/0
Wind: NNW 10
H.I.: 85-90
U.V.: 11- Very High
*Marine Forecast from NWS-Lake Charles
Tonight...South winds 5 to 10 knots. Seas 1 foot.
A slight chance of showers and thunderstorms.
Thursday...Southeast winds around 5 knots. Seas 1 foot.
A slight chance of showers and thunderstorms.
Thursday Night...South winds 5 to 10 knots. Seas 1 to 2 feet.
A slight chance of showers and thunderstorms.
Friday...Southwest winds around 5 knots. Seas 1 to 2 feet.
A chance of showers and thunderstorms.
Friday Night...Southwest winds 5 to 10 knots becoming west after midnight.
Seas 1 to 2 feet. A chance of showers and thunderstorms.
Saturday...Southwest winds 5 to 10 knots. Seas 1 to 2 feet.
A chance of showers and thunderstorms.
Thursday Tides:
High: 1:01a.m.
Low: 4:49p.m.
Climate Data- Courtesy of NWS Lake Charles
Low: 74 Normal Low: 73 Record Low: 61-1917
High: 87 Normal High: 91 Record High: 101-1990
Precipitation:
Rainfall Today: Trace
Month to Date: 4.95" Normal Month to Date: 3.95"
Year to Date: 38.66" Normal Year to Date: 37.19"
Sunrise Thursday: 6:47a.m.
Sunset Thursday: 7:41p.m.
-DM-
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