KATC StormTeam 3 Weather BLOG

Space Shuttle Atlantis is scheduled to land at the Kennedy Space Center Friday morning at 10:00am.  But as of this evening the de-orbit burn before 8:00am is a “no go ” due to limited visibility from scattered showers and thundershowers that should be in the vicinity of the Cape.  If the weather is better than expected NASA will bring the shuttle in on the first landing opportunity which will bring the track over Mexico, Brownsville and across the northern Gulf.  So we will likely not hear the sonic boom in Acadiana as the shuttle passes by due to mostly north/northeast winds across the area.  Interestingly enough, if NASA chooses to take the second landing opportunity, then the shuttle’s landing track would bring it over northern portions of Acadiana (right over Ville Platte) roughly at 11:24am with the craft landing at 11:39am.  Now because these are daytime landings and there will be plenty of cloud cover, we will likely not see the shuttle’s plasma trail at this time.  If the shuttle stays up another day we’ll check the the new suite of landing tracks just in case…but Atlantis may have to land at Edwards AFB in California or New Mexico as the weather may stay too active at the Cape through Saturday.  Although I’ll be taking a day off tomorrow, I’ll update accordingly on my twitter account at twitter.com/robperillo.

I find that it’s incredible that the shuttle is moving at MACH 24 (24 times the speed of sound or about 17,000mph) when it hits the Earth’s atmosphere at about 400,000ft on the west coast of Mexico and is decelerating like a brick slowing (due to increased friction of our atmosphere) to 4,000-5,000mph (only) as it passes our coast at about 150,000ft!  Roughly 5-8 minutes after the shuttle passes the sonic boom can be heard (if you’re close enough and lucky enough to hear it) and within a minute or two of us hearing the boom the craft is landing on the runway in Florida!  Rob

Tropical moisture will continue to flow in from a non-tropical low off of the Florida coast.  The low will drift westward, then northwestward toward the Louisiana/Mississippi Gulf coast.  The low should move inland late Saturday or early Sunday.  Clouds will move in today with a slight chance for showers later this afternoon or this evening.  Friday I’ll be looking for a 30% chance for widely scattered showers and storms.  By Saturday, the rain chance will climb to 50%.  If the low stays east of the area, the rainfall totals should be light.  Flooding rains may move over Mississippi, Alabama, and the Florida panhandle.  As the low moves inland, chances for rain should drop back to about 30% for Memorial Day with temperatures in the upper 80s.  A trough over the middle part of the country should pick up the low and swing it eastward toward the Mid-Atlantic states, and our weather should dry out later in the week.  Later today NOAA will release it’s 2009 Hurricane Season Prediction.  www.noaa.gov

The upper level and weak surface low in the Eastern Gulf of Mexico will continue to drift westward over the next several days ushering more clouds over the next days with slight rain chances for Thursday and a better chance of scattered showers and a few storms Friday.  The area of low pressure is expected to begin drifting northwestward and northward this weekend yielding a good chance of rain and storms Saturday and a pretty good chance of daytime showers and storms Sunday into early next week.  As I have mentioned over the last few days, we are not expecting any significant tropical development with this system but it will likely make for rough conditions offshore Thursday and Friday along with producing some waterspouts.  In addition, tropical funnel clouds may become more likely Friday into the weekend.  I’m not expecting organized severe weather with this system there may be some very healthy embedded storms this weekend into early next week.  Rainfall totals through Monday may be in the couple of inch range across portions of Acadaina the threat of heavier rains and flooding will be most likely over eastern-most Louisiana into coastal Mississippi, Alabama and the Florida Panhandle.  An upper trough approaching from the northwest for early to mid-next week will keep rain chances with us through mid-week but ultimately this system will pick up the meandering low and usher in drier and quite possibly cooler conditions late next week into the following weekend.  So while this weekend doesn’t look too great the following weekend is looking pretty good!  Rob

Our beautiful weather will continue through Wednesday but the upper low and disturbance in the eastern Gulf will likely bring scattered showers by the end of the week and perhaps a good chance of showers and storms this weekend.  As I mentioned yesterday the forecast hinges upon the movement of our system in the Gulf and how far to the west this system will get before it starts drifting northward and then northeastward by an upper trough and weak front early next week.  The National Hurricane Center chose not to fly the system in the eastern-most Gulf off the west coast of Florida since it was not showing any tropical characteristics nor do they expect that this system will develop tropically.  However, with that being said, this system will likely maintain a vigorous circulation and will likely keep it rather rough offshore especially Thursday and Friday.  In addition, there will ultimately be some very heavy rains by this weekend along the Gulf Coast with best bets mainly over Eastern Louisiana through the Florida Panhandle.  For Acadiana, the weather will stay outstanding tomorrow with plenty of sunshine but the outer edge of the upper low will begin to usher in some clouds by late in the day.  Thursday will bring partly cloudy skies with the chance of afternoon/evening showers and a few storms.  Rain chances should increase a little more on Friday and could go on the high side for this weekend depending on the ultimate track of the upper and surface low.  It is completely in the realm of possibilities that the system stays far enough to the east of us to keep us on they dry side of things, but the prudent forecast factors that the ridge along the east coast will force this system to west bringing us close enough to the good instability and deeper tropical moisture that would yield healthy rain chances.  Activity should be mostly daytime/evening enhanced with activity quieting down during the night.  Once any moisture and instability gets here it will have a hard time leaving so enhanced rain chances may continue into early next week.  Highs will stay in the low-mid 80s through the weekend while lows unfortunately moderate back into the more uncomfortable range after tonight…upper 60s to lower 70s.  Once the rain chances decrease next week the heat will be on with highs back near 90 for mid-next week.   Enjoy the cool temps tonight!  Rob

Although our weather has been gorgeous with nice and cool conditions persisting through the next 36 hours we are indeed watching tropical moisture and disturbances over Florida and the Northwestern Caribbean.  As I alluded to last Wednesday in this blog, the models were indicating some tropical or sub-tropical development with an upper low and several weak areas of surface low pressure over the Eastern Gulf, Florida Atlantic and extreme northwest Caribbean later this week.  While it is very early to talk about tropical activity in the Gulf of Mexico water temperatures are mostly in the upper 70s to near 80.  This is barely warm enough to support pure tropical activity but not enough (nor deep enough heat content-wise) to support anything that would be long-lived nor anything that would be intense…such as a hurricane.  However, there will probably be an organized tropical or sub-tropical “hybrid” across the Eastern Gulf of Mexico later this week with current models bring the system as far west as Louisiana before it stalls and turns back to the east-northeast this weekend or early next week.

A “hybrid”storm can have  some tropical characteristics and some non-tropical characteristics such as typical cold-core winter time systems that we see here.  Most times a subtropical/hybrid low starts out as a cold core low that’s associated with an upper level trough of low pressure.  The transition to a hybrid begins when the cold core upper low or trough departs while at the surface thunderstorms near the center begin replacing the upper cold core low by injecting warmer conditions in mid-levels from the process of latent heat of condensation…when this process matures winds aloft begin to lighten up and then upper level high pressure begins to build over the center of circulation…this is why you see the whispy upper level cirrus clouds churning anticyclonically outward (or clockwise) like a pinwheel in mature hurricanes.

So what’s the bottom line for us?  Our beautiful weather will continue through Wednesday (highs near 80/lows in the 50s) but by Thursday the aforementioned system will begin to drift to the west ushering some clouds and a few tropical showers into the area Thursday and Friday.  Initially we will be on the dry side of this system through Friday which will limit the moisture and still provide intervals of sun and nice and breezy conditions so I don’t look for it to get too warm through the weekend.  This weekend is up in the air with the possibility of healthy rain chances and tropical downpours depending on our system’s future path, organization and intensity…we may completely bust on the forecast and not see much rain but with that being said, there will more than likely be some serious rainfall and flooding problems in spots anywhere from Texas to Georgia with this system as it will be a very slow-mover and may linger somewhere over the Gulf South and/or Southeast U.S. for the better part of the week.   Incidentally the first named storm, or sub-tropical/hybrid storm will be “Ana”.  Rob

A cold front blasted across the state today making it feel like late winter instead of mid spring. Temperatures Sunday night are expected to dip to the mid 50s. Some record lows across the state may be set or tied over the next couple of days if the low gets down to 53 degrees. Through the week a strong area of high pressure keeps it clear and comfortable with a gradual warm up.

Computer models are still picking up on a low moving across the Gulf, starting out as a non tropical low and drifting westward. Some models disagree as to the strength and path so we’ll have to wait to see if it develops. Even if it does develop we are expected to stay on the west side (dry side) of the system making conditions offshore rough. The main difference of a non tropical low and a tropical low is where they get they’re strength. Tropical lows grow and develop over warm water and have the warmest temperatures near the center of low pressure. Non tropical lows form in enviornments with a temperature difference and are usually associated with cold fronts. The coolest temperature is near the core of the low. They can sometimes start as non tropical and warm over the warm waters and become either tropical or sub-tropical (having characteristics of both tropical and non tropical).

In the meantime, enjoy the sun shine!

If you’re tired of sweating in the heat and humidity there is some relief on the way.  A relatively strong cold front will push through Sunday giving us drier air and cooler temperatures, briefly. No severe weather is expected but we can’t rule out a few heavy downpours and rumbles of thunder. By Monday morning temperatures will dip into the mid 50s with highs in the upper 70s.

High pressure rules through the week giving us sunny skies and northerly winds. But the pattern changes toward the end of the week as an upper level low drifts westward across the Gulf. Rain chances return Thursday into Friday.

For the past couple of days temperatures have been heating up with sea breeze storms kicking up in the afternoon. With these storms there have been a few reports of tropical funnel clouds, typical with storms this time of year. The storms dump heavy rain and occasionally hail while slowly moving inland. Rain should increase in coverage Saturday ahead of a strong cold front. There will be a slight chance of some of the storms becoming strong to severe before everything clears out Sunday evening. Then much drier and cooler air will push in the area. The front will bring the lows down to the mid 50s with highs in the 70s. That will be about 10 degrees below a mid-May normal temperature. We will enjoy dry weather through the week but computer models are picking up on a low near Florida that may move westward into the Gulf toward the end of the week. We’ll have to see if it develops any tropical characteristics but we are about 15 days from the official start of the hurricane season.

Enjoy your weekend!

Our summer-like weather will continue for a few more days with a slight increase in rain chances through Friday while it could get rather stormy by Sunday.  But the good news is that nice and cool weather will likely follow early next week.  On Thursday a frontal trough well to our north could send an upper level impulse southward that could translate to a few afternoon showers and storms.  On Friday, deeper tropical moisture may advect northwestward from the Gulf of Mexico translating to widely scattered daytime showers and a few storms with rain chances getting closer to 30%.  This weekend may get more dynamic with a stronger series of atmospheric perturbations moving in from the north; combined with deeper moisture in the area, higher rain chances are possible Saturday and will be likely for Sunday.  There will probably be a severe weather threat this weekend, especially for Sunday.  This pattern could bring storms that could be capable of producing damaging winds and large hail so keep an eye out for that especially Sunday.  Temperatures will top out in the mid-upper 80s through Saturday but may stay in the upper 70s to lower 80s Sunday with clouds and storms likely.  Clear skies and cooler more spring-like conditions are looking more likely early next week with highs near 80 accompanied by lows dropping into the upper 50s.  Interestingly enough the long range models develop a “cut-off” upper low in the Eastern Gulf next week with a slow drift to the west possible which could bring scattered showers back by the end of next week.  In addition, “upper troughiness” appears to persist across the Northeastern Gulf into the Florida Atlantic area through the end of the month which may involve some sub-tropical development for someone down the road…this would be coincidental with the beginning of (or just before) the official beginning of tropical season…we’ll see.  Rob

Our summer-like weather will continue into the weekend but changes are on the way for Sunday into early next week.  Drier more stable air moved in last night and this morning in the wake of yesterday’s storms and the retreating frontal boundary.  The result was just a few isolated showers this afternoon and I would expect more of the same tomorrow and perhaps Thursday.  Chances of getting wet will be near 10% tomorrow and less than 20% Thursday, while deeper tropical moisture and more instability should yield a 30% chance of daytime showers and a few storms Friday and Saturday.  Rain chances could go higher Saturday but we’ll keep the 30% for now.  A frontal trough will likely yield a fairly good chance of showers and some locally heavy thunderstorms Sunday, and if all goes per the latest model runs, we’ll see  more pleasant weather into early next week.  Mostly sunny skies are currently in our forecast for Monday and Tuesday of next week with highs in the lower 80s but more importantly overnight lows will get close to 60 degrees!  Sounds almost exciting for now…but it’s also a reminder that we have embarked on our long, hot summer pattern, so any break we see is welcomed with open arms!