DocNDswamp's WunderBlog

SE LA Wx...Tropical Analysis...

By: DocNDswamp, 10:36 PM GMT on June 23, 2006

Note: This entry posted Friday aftn...June 23 2006. Additional wx updates to entry will be added in comments section.

SE LA Wx Update:
Fri June 23 2006 5 PM CDT

7 Day Outlook:
Another upper pattern shift on the ridge builds over the Great Basin out west and moderate troughing from Great Lakes to Miss R. / TN Valley deepens by Sun / Mon. Weak cold front will bring increased chance of rain / T-storms (40-60%) in the picture for SE LA on Saturday into early Sunday...followed by return to upper WNW flow and drying out once again by late Sunday into next week...This will largely kill off seabreeze convection we've had last few days...and moderate the record high temps across the South...although with daytime heating alone will keep a slim 10 - 20% POP into the middle of forecast period. Slightly cooler morning temps with lower dewpoints should bring us back to climo averages, with highs generally in the low 90's will rule...rising back to mid 90's possibly later in the period. Cold front is expected to stall to the immediate ESE of LA coast, running stationary into AL / GA and NELY...separating N Gulf region, with more tropical moisture remaining into early next week to the east of boundary...along with better POPS from FL northward. W / WNWly progressing Bahama low system not likely to reach far enough westward to affect SE LA as it will begin lifting NWD into the frontal trof.

Severe Drought conditions remain across our area... only briefly lessened by this past week's daytime heating / seabreeze aftn T-storms. Finally had a rare, respectable T-storm drop 1.78" at my location on Wed June 21, appropriately on the summer solstice... First significant rain since late April. Raised my yearly total from a pathetic 9.69" to a still pathetic 11.47" - still near 18" below climo averages. A few iso T-storms appeared yesterday just N / NW of this location...and a very few possible again today.


Tropical Update:
In the Atlantic we're still watching the slow development of the Bahamas low.... Long a persisting mid-upper level low, a broad surface low pressure area is now reflected beneath the upper low...and may very well become a subtropical depression - as I mentioned yesterday morning in my previous entry - due to the upper environment from which it has originated...and apparently remains in. Surface pressures in the region to the west of the system have fallen from the steady 1016 - 1018 mb regime of last several days to near 1012 mb near Eleuthera, Bahamas as the area of low pressure has tracked W / WSW response to upper high over SE shifting EWD with slow approach of cold front and developing trof near the S Plains / Miss Valley. Slight pressure falls along FL E to SE coast to near 1014 mb also noted at this time. System should continue tracking W toward the Florida peninsula over the next 12 - 24 hrs, with more of WNW / NW movement thereafter.

It must be noted some model runs have tracked the low across S Cen FL and into the extreme NE Gulf by Sun / Mon before turning it NWD to merge with frontal trof...which seems less likely...while others see a general NW motion toward NE FL. It could also easily approach the coast, then run parallel NWD. Regardless, the net effect will be breezy 15 - 25 mph gusty NELY winds and increased rainfall in next 24 - 72 hrs for FL as it merges or slides along the front up into the SE US / Carolinas. No rapid strengthening is expected as future deepening of this system should be slow, but reasonably steady... with only a very small probability for it to become a very weak tropical or subtropical storm...but that's a stretch ATT. Other than hvy rain / flash flooding concerns and breezy conditions, no major threat is anticipated.

Have also noted the GFS, CMC and NOGAPS hint at another developing system over the next 48+ hrs in the Atlantic roughly near 20N 60W...near the hvy convection that appears to be separating from and to the east of the current Bahamas low. Will have to see...and if does, could remain an offshore fish storm as it looks now.

Caribbean wave is now inland over Nicaragua / Honduras and continuing to move W / WNW toward the E Pac...hvy stream of convection it pulled NWWD from Panama looked impressive last couple days under that anticyclone. Development is not expected as it appears will mostly stay over inland regions. Guidance from a few days ago indicated the possibility that some of this could drift toward the Gulf in time...Remains to be seen and were the coming frontal trof stronger and not be forecasted to just wash out, and fill in behind it with more dry air, would see some concern...We'll give this another look in a few days... Any potential cyclogenesis in the E Pac is tempered by another huge pool of dry subsiding air west of 110 - 115W...which destroyed that very favorable wave there 3 days ago.....

Doc's 2006 Tropical Season Outlook:
18 Tropical Systems
2 Tropical/Subtropical Depressions
16 Named Storms
9-10 Hurricanes
5-6 Major Hurricanes (Cat 3-5)

Updated: 4:41 PM GMT on June 25, 2006


SE LA - Rain? Tropics subdued...for now.

By: DocNDswamp, 1:55 AM GMT on June 16, 2006

Most recent Weather and Tropical Updates to this entry are posted below in Comments section...

SE LA Wx Update
Thu June 15 2006 8:30 PM CDT

Outlook: Rain?
Well if the coming forecast pans out, those of us who live in the "Gulf Desert Northwest" may see some relief from this horrible drought the next few days...although the heaviest - no surprise - will be focused west of SE LA, particularly E TX to W LA coastal regions extending NWD. At the surface - the Atlantic ridge is building westward bringing a return to southerly winds and increasing humidity...also a plume of moisture from a weak wave and that old surface trof that aided in Alberto's formation has been shunted into the W Gulf around the SW / W periphery of the Atlantic ridge. In the upper levels, broad high pressure remains centered over W Cuba / N Carib / E-Cen Gulf...while a mid-upper level low is positioned near the TX - MX border and the SLY flow up around it's east side is bringing deep tropical moisture NWD and rapidly increasing RH values in the mid-up levels - juicing the atmosphere substantially. Additionally, a slow EWD advancing trof now E of the Rockies will enhance convective activity, esp in N Cen TX in time, where also needed.

With a seabreeze set-up, daytime heating adding instability and aforementioned factors...this looks to be the best chance many of us here have seen in awhile for some rain. (numerous shwrs / T-storms approaching coast as I write!) By Friday, most of the shwrs / T-storms should be concentrated from near the upper TX coast to SW / S Cen LA and northward...with w scat to possibly numerous activity spreading into SE LA. Currently the outlook for POPS across SE LA stands from 30 to 50% on Fri - Sat...and tapering to typical 20-30% the remainder of the period...and could be drier again by early next week. Temps should avg near normal with lows in the low-mid 70's and highs up 80's to near 90...with higher and more normal humidity levels, ie - the muggies least for the short term.

The outlook appears solid... but like many, I'll believe it when rain gauge actually measures here. The current drought in my area is one of the worse seen...and we've been more prone to it since the mid-90's. Yeah, I know your tired of hearing about it...blah, blah, blah...LOL. So far my year-to-date total remains at 9.69" thru June 15...while the climatological average says we should be closing in on 27" by now! Only the federal govt could run up a larger deficit!!! Hope to report better news by tomorrow!


Tropical Update:
Quiet is the word...for now. As Alberto departs, Atlantic ridge is building westward across the W Atlantic Basin...surface pressures are rising strongly. Despite all those mid-Atlantic waves, no sustained development is expected for at least the next 3-5 days. The Caribbean wave, now WSW of Jamaica...and quite sheared, has no surface low...had only a faint, weak mid-level circulation at best. Development is not expected as it continues moving WNW @ 15 kts...and it's remnants could move into the Gulf. (It must also be noted that models indicate upper level shear will be lowering across the Gulf next will stay vigilant). SW Carib above Panama remains with low ambient surface pressure...but fairly typical for the region. Same in the E Pac...and despite heavy convection in both areas, no sign of organization at this moment. As usual, we'll keep alert!

Doc's 2006 Tropical Season Outlook:
18 Tropical Systems
2 Tropical/Subtropical Depressions
16 Named Storms
9-10 Hurricanes
5-6 Major Hurricanes (Cat 3-5)

Updated: 2:19 PM GMT on June 17, 2006


SE LA Drought Woes...Tropical Update

By: DocNDswamp, 4:04 AM GMT on June 05, 2006

Note: Any additional SE LA wx updates and Tropical Updates to this entry will be placed in the comments section...

SE LA Wx Update
Sun June 4 2006 11 PM CDT:

Weekly Outlook: Dry Start to June...
Late season cool front has brought very dry air across SE LA...and cooler morning temps. Low temps Sunday dropped to low-mid 60's across much of SE LA - 62 @ Baton Rouge, 64 @ Houma, with a few areas on the northshore L Pontchartrain (FL Parishes) dipping into the upper 50's, such as 57 @ Slidell - the "icebox" of SE LA. Temps will rise as week progresses with range of mid 60's / low 70's to max of up 80's / low 90's...humidity values - (dropped to a desert-like 27 % today!) - will moderate slowly upward, although rain chances stay very slight most of this week as generally dry NWLY upper flow remains...and next upper disturbance appears will likely affect areas east of us, although a 10 - 20% POP is reasonable. By the next week (June 11-17), deeper tropical moisture may return to provide some drought relief somewhere on the N Gulf coast...most likely E of SE either aftn seabreeze T-storms, an upper level disturbance, or possible weak tropical disturbance. Model runs have been hinting / flipping at this somewhat - usual disclaimer applies to outlook beyond 5 - 7 days. Too early to speculate further...other than to say this area is waaaaay overdue for precipitation. SE LA has been locked under strong upper level ridge...and no sign of significant shift yet.

Extreme Drought continues...
For SE LA the month of May was either the driest or second driest on record for many of us, depending on specific location...despite all the convective activity during the first 7 days and the last 3 days of the month. While some isolated areas picked up 3-4", most had less than a third inch. My location had grand total of .16", a new record beating out previous driest May of 2000 when I had .41". A few other May tallies around this area include:

Vandebilt Catholic High, Houma, LA - MONTHLY RAIN: 0.07"
Hahnville High School, Boutte, LA - MONTHLY RAIN: 0.14"
Emergency Operations Center, Napoleonville, LA - MONTHLY RAIN: 0.16"
DocNDswamp, Bayou Cane, LA (NW Houma) - MONTHLY RAIN: 0.16"
Houma Jr. High, Houma, LA - MONTHLY RAIN: 0.24"
New Orleans LAI Airport, Kenner, LA - MONTHLY RAIN: 0.28"
Louisiana State Police, Gray, LA - MONTHLY RAIN: 0.43"

Fairly pathetic, eh?...and here were the lucky ones:

Port Fourchon, Fourchon, LA - MONTHLY RAIN: 0.65"
St. Gregory Barbarigo School, Houma, LA - MONTHLY RAIN: 0.70"
Grand Isle High School, Grand Isle, LA - MONTHLY RAIN: 0.82"
St Joseph School, Thibodaux, LA - MONTHLY RAIN: 1.24"
Baton Rouge ASOS, Baton Rouge, LA - MONTHLY RAIN: 1.26"

Obviously, we have averaged about 4 - 6" below normal for May...Areas across S Cen / SW LA faired a little better (Morgan City westward), generally receiving 2 - 4" amts...but barely offsetting long term drought conditions. Thru May, my yearly total stands at 9.67"...and only received another .02" so far in June...It's GOT TO RAIN SOON! Maybe...If not, and a dry June ensues, widespread crop damages will result...and saltwater intrusion into brackish/freshwater habitat could become problematic.
Compounding this situation - we had NO substantial annual spring rise on either the Mississippi or Atchafalaya Rivers to help flush and replenish freshwater habitats. We NEED a tropical rainmaker like an Allison or Juan or a TD 2E, ...just not another Katrina or Rita.

Tropical Update:
E Pac remains the center of TD 2E formed on Sat June 3 below S MX and followed in TS Aletta's footsteps with a slow drift NWD...dumping copious amounts of rain across the Mexican Riviera, particularly near Acapulco which has received over a foot of rain and nearly twice that amt over inland mountain regions. TD 2E's surface low reached peak intensity of 1005 mb (29.68") with max winds around 30 kts. Now weakening as it drifts E over Acapulco...and dissipates steadily, but threats of mudslides and localized flash flooding remains. Unfortunately, this pattern is likely to continue repeating...and another system will probably organize in time to ruin tourists' vacation plans next weekend...for the third weekend in a row! Drought relief has fast become a flooding concern....

On the Atlantic side...should remain status quo this coming week...with easterly waves embedded at low latitudes along the ITCZ with no development expected unless they survive passage into the E Pac to add to the excitement there. In the Gulf, upper level westerlies of 30 - 50+ kts from the subtropical jet are fully entrenched down to near the Yucatan...and EWD over Cuba and the Bahamas. The W Caribbean, now moisture enriched has shown signs of activity along a stationary trof and a series of weak surface lows that formed from near Panama to recently, NE of Honduras. No sustained development is expected as marginally favorable upper environment is confined to small areas for now. The pattern Dr. Jeff Masters mentioned - W Carib system crossing Cuba / Bahamas - is still viable due to SELY position of Azores / Bermuda high combined with subtropical jet flow, but at this time the dominant upper shear is too high for TC development.

However - and this is really going out on a limb - the overall pattern may shift and become a bit more favorable by end of weekend and esp. following week (June 11 - 17) ...Strong wind shear over Gulf may slacken, but could be replaced with an upper level low (not particularly conducive for TC) over the Cen / W Gulf...while an upper anticyclone lies over the NW Carib / Cuba by mid-week of that period. (Side-note: an earlier run showed the anticyclone over the Gulf, now an upper low...LOL.) Whether a TC develops is questionable - none of the vorticity charts indicate anything - but a blob of deep tropical moisture could come out of Caribbean into the Cen / E Gulf...with 2nd blob also in W Carib. Also near this same time frame, an Atlantic wave could come under favorable conditions E of Windward Is, if it rises up in latitude...although a bit early there, climatologically speaking. This period would be the soonest I'd expect a trop disturbance with ANY chance of development to appear on the Atlantic side...
I've based the long-range speculation by viewing several model runs for continuity...and climatology trends. I must add - any speculation beyond 5-7 days is just that! Despite any continuity, long-range forecasts are inherently error prone... We could be waiting a lot longer for Alberto yet...or even a TD. Just my 2 cents worth...LOL. And a few days from now, I'll probably look pretty stupid with this outlook and have to adjust...when the model runs reverse themselves. More LOL! ...We'll see.

BTW - Busy schedule...not much time to blog "live" (as usual lately) ...and will be leaving for short vacation later this week, between June 8 - 12...and incommunicado w/ no computer. LOL, what will I do? Enjoy, I hope!


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