10pm Update on Tropical Depression # 5 – Wednesday

TROPICAL DEPRESSION FIVE DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL052012
1100 PM AST WED AUG 01 2012

SINCE THE PREVIOUS ADVISORY…CONVECTION ASSOCIATED WITH THE DEPRESSION HAS WANED. HOWEVER…IT IS NOT UNUSUAL FOR CONVECTION  TO FLUCTUATE IN ASSOCIATION WITH WEAK AND DEVELOPING TROPICAL CYCLONES. EROSION OF THE INNER CORE CONVECTION IS ALSO LIKELY DUE TO THE ENTRAINMENT OF DRY MID-LEVEL AIR INTO THE NORTHWEST QUADRANT AS NOTED IN VARIOUS WATER VAPOR PRODUCTS OVER THE PAST 8 HOURS. THE INITIAL INTENSITY REMAINS AT 30 KT…WHICH IS SUPPORTED BY A UW-CIMSS ADT INTENSITY ESTIMATE OF T2.2/32 KT.

THE INITIAL MOTION REMAINS 285/16 KT. THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK OR REASONING. A DEEP-LAYER SUBTROPICAL RIDGE TO THE NORTH OF THE CYCLONE IS EXPECTED TO REMAIN IN PLACE THROUGH THE FORECAST PERIOD….WHICH SHOULD KEEP THE DEPRESSION MOVING IN A GENERAL WEST-NORTHWESTWARD MOTION THROUGH 120 H. THE NHC MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON THIS SCENARIO…AND THE CURRENT FORECAST TRACK IS JUST AN UPDATE OF THE PREVIOUS ADVISORY TRACK…AND LIES NORTH OF THE MODEL CONSENSUS DUE TO THE MORE SOUTHERLY GFDL MODEL TRACK THAT IS CONSIDERED TO BE AN OUTLIER DUE TO IT DEPICTING A MUCH WEAKER SYSTEM THAN FORECAST.

ONCE THE AFOREMENTIONED DRY AIR ENTRAINMENT PROCESS ABATES… CONVECTION SHOULD REDEVELOP NEAR THE CENTER SINCE THE SYSTEM STILL HAS A VERY ROBUST CIRCULATION AS NOTED IN RECENT SSMI AND AMSU MICROWAVE SATELLITE DATA. HOWEVER…VERTICAL SHEAR CONDITIONS ARE ONLY EXPECTED TO BE MARGINALLY CONDUCIVE FOR SLOW DEVELOPMENT TO OCCUR OVER THE NEXT 48-72 HOURS. BY DAYS 4 AND 5…MORE SIGNIFICANT INTENSIFICATION WILL BE POSSIBLE WHEN THE CYCLONE IS LOCATED OVER THE WARMER CARIBBEAN SEA AND IN A MORE FAVORABLE UPPER-LEVEL WIND ENVIRONMENT. THE INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY…AND IS CLOSE TO A BLEND OF THE SHIPS AND LGEM INTENSITY FORECAST MODELS.

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WVUA Chief Meteorologist

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Tropical Depression # 5 Update – Wednesday 6 p.m.

…DEPRESSION CONTINUES TO MOVE TOWARD THE WINDWARD ISLANDS…

LOCATION…12.4N 49.8W

ABOUT 760 MI…1220 KM E OF THE WINDWARD ISLANDS

MAXIMUM SUSTAINED WINDS…35 MPH…55 KM/H

PRESENT MOVEMENT…WNW OR 285 DEGREES AT 18 MPH…30 KM/H

MINIMUM CENTRAL PRESSURE…1008 MB…29.77 INCHES

SUMMARY OF WATCHES AND WARNINGS IN EFFECT…

A TROPICAL STORM WATCH IS IN EFFECT FOR…

* BARBADOS…ST. VINCENT AND THE GRENADINES…AND DOMINICA

* ST. LUCIA

* MARTINIQUE AND GUADELOUPE

INTERESTS ELSEWHERE IN THE LESSER ANTILLES SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA…GENERALLY WITHIN 48 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA…PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.

DISCUSSION AND 48-HOUR OUTLOOK

AT 800 PM AST…0000 UTC…THE CENTER OF TROPICAL DEPRESSION FIVE WAS LOCATED NEAR LATITUDE 12.4 NORTH…LONGITUDE 49.8 WEST. THE DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR 18 MPH…30 KM/H…AND A WEST-NORTHWESTWARD TO WESTWARD MOTION AT ABOUT THE SAME FORWARD SPEED IS EXPECTED OVER THE NEXT 48 HOURS.  ON THE FORECAST TRACK…THE CENTER OF THE TROPICAL CYCLONE SHOULD BE NEAR THE WINDWARD ISLANDS ON FRIDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH…55 KM/H…WITH HIGHER GUSTS.  SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS… AND THE DEPRESSION COULD BECOME A TROPICAL STORM TONIGHT OR ON THURSDAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB…29.77 INCHES.

Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather


Radar Update / Wednesday Afternoon Forecast Discussion…Tropical Update…Beach Forecast – 5:40PM Update

Good Wednesday afternoon to you! We’re watching radar trends this afternoon, as severe storms move across north and east Mississippi. These storms are moving southeast at 30 mph. The Storm Prediction Center has placed a severe thunderstorm watch for much of west Alabama until 10pm tonight. The severe thunderstorm watch includes the counties outlined in pink. Sumter, Greene, Hale, Pickens, Tuscaloosa, Lamar, Fayette, Walker, Marion and Winston County is under a watch in our area. I’ve circled where the best chance of scattered severe storms in west and northwest Alabama. Even in the threat area, the risk of severe weather isn’t all that high. Scattered strong to severe storms are still possible through 10pm tonight, but storms will die out shortly after 10pm. Radar trends show storms weakening for now, so the threat seems to be dropping a bit.

If a strong to severe storm moves into your area, expect the threat of damaging winds, hail and intense cloud to ground lightning. Not everyone will get rain, and this will not be anything like the event we had on Tuesday morning. This system is much weaker than Tuesday morning’s event. We just want you to know there is a fair threat of scattered strong to severe storms across parts of our area. Again, the main threat will happen in northwest Alabama.

The chance of these scattered strong to severe storms will continue to be possible through Sunday. Rain chances will range between 30 and 40% for the rest of the week and into the weekend. It will not rain all day everyday, but some spots will get a good soaking, followed by dry and sunny conditions. Highs will  remain in the lower to middle 90s through Sunday. The upper air ridge will continue to split over the southeast this week and into the weekend. This will allow a slight northwest flow aloft to continue and some cooler temperatures aloft. Both will aid in the development of showers and storms across our state. It will not be a total washout for the weekend, so most activities should get in just fine. If a storm moves your way, go indoors. Just like the past few days, all storms will produce an incredible amount of lightning.

There is some hint of a cold front reaching Alabama early next week. I have a 30% chance of storms early next week due to rather low confidence in computer data for now. If more models suggest the front will arrive in our area, rain chances may have to be bumped up on Tuesday and Wednesday. Highs will remain the 90s, with lows in the 70s.

The beach forecast is looking fair over the next 5 days. Much like our weather, scattered storms are possible along the Alabama Gulf Coast and Florida Panhandle each day through the weekend. It will not be an all day type of rain, but a storm or two is certainly possible. Highs along the coast will remain in the upper 80s to around 90.

We are also watching the tropics. Tropical Depression # 5 has developed this afternoon. It could become Tropical Storm Ernesto over as early as tonight. I’ve got a full update on that system a few posts below this one. We have lots of time to watch it, but confidence is increasing that the system may reach the Gulf of Mexico as a hurricane. I’ll update your forecast as we get closer.

Send us your weather pictures! Send them to weather@wvuatv.com. Also, look us up on facebook and twitter. Like us on facebook by searching facebook.com/wvuaweather or WVUA-TV Weather. You can find us on twitter by searching weather@wvuatv.com or WVUA-TV Weather. Great way to get weather updates! Plus, facebook is a great way to send us weather pictures. Simply tag us!

Join us live on WVUA-TV weekdays at 4, 5, 6 and 10 pm and weekends at 10pm for the very latest on your news, weather and sports.

Richard Scott

WVUA Chief Meteorologist

rscott@wvuatv.com

Tropical Depression # 5 forms…Could Become A Hurricane! Tropical Update 4pm Wednesday

DURING THE DAY…VISIBLE SATELLITE IMAGES SHOWED THAT THE LOW-LEVEL CIRCULATION OF THE LOW PRESSURE SYSTEM TO THE EAST OF THE WINDWARD ISLANDS HAS BECOME BETTER DEFINED.  DEEP CONVECTION HAS PULSED A BIT…AND IS SOMEWHAT LACKING OVER THE NORTHERN PART OF THE CIRCULATION.  HOWEVER THE SYSTEM HAS NOW ACQUIRED SUFFICIENT ORGANIZATION TO BE CLASSIFIED AS A TROPICAL DEPRESSION.  THE INITIAL WIND SPEED IS SET AT 30 KT IN ACCORDANCE WITH DVORAK ESTIMATES FROM TAFB AND SAB.  FORECASTING INTENSITY CHANGE IS ALWAYS A CHALLENGE…AND IS PARTICULARLY TRUE IN THIS CASE. MODERATE VERTICAL SHEAR…ASSOCIATED WITH A LARGE UPPER-LEVEL LOW TO THE NORTH OF THE DEPRESSION…IS LIKELY TO AFFECT THE SYSTEM FOR THE NEXT COUPLE OF DAYS.  THUS ONLY SLOW STRENGTHENING IS ANTICIPATED DURING THE FIRST HALF OF THE FORECAST PERIOD.  LATER ON…THE INTENSITY FORECAST UNCERTAINTY INCREASES.  OUR BEST TWO GLOBAL MODELS ARE AT ODDS AS TO HOW THE SYSTEM WILL EVOLVE AS IT MOVES OVER THE CARIBBEAN.  THE GFS FORECASTS THE UPPER-LEVEL ENVIRONMENT TO BECOME QUITE CONDUCIVE FOR STRENGTHENING BY THE END OF THE FORECAST PERIOD…WHEREAS THE ECMWF MODEL SHOWS THE SYSTEM DEGENERATING INTO A TROPICAL WAVE.  THE OFFICIAL FORECAST LEANS TOWARD TO THE GFS…BUT TIME WILL TELL.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 285/16.  GLOBAL MODELS DEPICT A STRONG MID-TROPOSPHERIC ANTICYCLONE TO THE NORTH OF THE TROPICAL CYCLONE FOR THE NEXT SEVERAL DAYS.  THIS STEERING PATTERN SHOULD CAUSE A WEST-NORTHWESTWARD TO WESTWARD MOTION AT ABOUT THE SAME SPEED THROUGH MUCH OF THE FORECAST PERIOD.  A WEAKNESS OVER THE GULF OF MEXICO COULD CAUSE SOME SLOWING AND BIT OF A NORTHWESTWARD TURN LATE IN THE PERIOD.  THE COMPUTER MODELS ARE IN GOOD AGREEMENT…AND THE NHC TRACK FORECAST IS NOT FAR FROM THE MODEL CONSENSUS.

Send us your weather pictures! Send them to weather@wvuatv.com. Also, look us up on facebook and twitter. Like us on facebook by searching facebook.com/wvuaweather or WVUA-TV Weather. You can find us on twitter by searching weather@wvuatv.com or WVUA-TV Weather. Great way to get weather updates! Plus, facebook is a great way to send us weather pictures. Simply tag us!

Join us live on WVUA-TV weekdays at 4, 5, 6 and 10 pm and weekends at 10pm for the very latest on your news, weather and sports.

Richard Scott

WVUA Chief Meteorologist

rscott@wvuatv.com

Severe Thunderstorm Watch Until 10pm! Watching Storms Close! – Wednesday Update 3pm

Much of west Alabama has been placed under a severe thunderstorm watch. We’re watching a developing complex of storms over northeast Mississippi. These storms now look to impact much of west Alabama between 4pm and 10pm tonight. Stay alert. Severe thunderstorm warnigns are very possible in the watch box. I don’t expect tornadoes today, but damaging strait line winds are very possible. Stay here for udpates. Here’s a statement from Storm Prediction Center:

THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
  
          NORTHWEST ALABAMA
          NORTHERN AND CENTRAL MISSISSIPPI
          SOUTHWEST TENNESSEE
  
   EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 305 PM UNTIL 1000 PM CDT.
  
   HAIL TO 2 INCHES IN DIAMETER…THUNDERSTORM WIND GUSTS TO 75 MPH…AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
  
   THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60  STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHWEST OF MUSCLE SHOALS ALABAMA TO 65 MILES SOUTH SOUTHEAST OF JACKSON MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE  ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).
  
   REMEMBER…A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY  DO PRODUCE TORNADOES.
  
   OTHER WATCH INFORMATION…CONTINUE…WW 544WW 546
  
   DISCUSSION…SMALL SCALE IMPULSE DEVELOPING SEWD ACROSS THE MS VALLEY WILL AID ASCENT ACROSS A VERY UNSTABLE AIRMASS ACROSS PARTS OF MS AND THE TN VALLEY THROUGH THE LATE AFTERNOON. WHILE DEEP-LAYER FLOW IS NOT PARTICULARLY STRONG WITH THIS IMPULSE…MAGNITUDE OF  INSTABILITY /MLCAPE AROUND 3000-4000 J PER KG/ WILL LIKELY COMPENSATE FOR LIMITED SHEAR SO THAT MULTICELLUAR STORMS CAN ORGANIZE SUFFICIENTLY FOR A DAMAGING WIND AND HAIL THREAT ACROSS THE WATCH AREA INTO THE EVENING.

Send us your weather pictures! Send them to weather@wvuatv.com. Also, look us up on facebook and twitter. Like us on facebook by searching facebook.com/wvuaweather or WVUA-TV Weather. You can find us on twitter by searching weather@wvuatv.com or WVUA-TV Weather. Great way to get weather updates! Plus, facebook is a great way to send us weather pictures. Simply tag us!

Join us live on WVUA-TV weekdays at 4, 5, 6 and 10 pm and weekends at 10pm for the very latest on your news, weather and sports.

Richard Scott

WVUA Chief Meteorologist

rscott@wvuatv.com

Watching Storms in Northeast Mississippi… Isolated Storms This Eve and Tonight… Wednesday Update 2:45pm

Good Tuesday early afternoon! I’m watching a batch of storms develop in northeast Mississippi at this 2pm hour with interest. A couple of storms have gone severe ahead of a weak upper air disturbance. While the risk of storms is low around central and west Alabama this evening and tonight, we’ll have to watch radar trends close incase these storms become better organized. At this point, there’s a 30% chance of rain at your house this evening and tonight. If storms contine to grow over northeast Mississippi as they slide southeast, I may have to make some changes to the forecast. At this point, the best chance of scattered storms this evening will occur northwest of Tuscaloosa; even there, the chance is fairly low. If you’re outdoors when a storm moves close to your area, go inside. Even tiny storms will produce lots of lighting. If a severe storm reaches our area, damaging winds will be the primary concern. Stay tuned for any updates.

Better rain chances will arrive on Thursday, Friday, Saturday and Sunday.

Send us your weather pictures! Send them to weather@wvuatv.com. Also, look us up on facebook and twitter. Like us on facebook by searching facebook.com/wvuaweather or WVUA-TV Weather. You can find us on twitter by searching weather@wvuatv.com or WVUA-TV Weather. Great way to get weather updates! Plus, facebook is a great way to send us weather pictures. Simply tag us!

Join us live on WVUA-TV weekdays at 4, 5, 6 and 10 pm and weekends at 10pm for the very latest on your news, weather and sports.

Richard Scott

WVUA Chief Meteorologist

rscott@wvuatv.com

 

Heat Advisory Today Now – 9pm… Use Caution! Wednesday Update 11:45am

…HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 9 PM CDT THIS EVENING…

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A HEAT ADVISORY…WHICH IS IN EFFECT FROM NOON TODAY TO 9 PM CDT THIS EVENING.

* TEMPERATURES…REACHING THE MIDDLE TO UPPER 90S THIS AFTERNOON.

* HEAT INDEX VALUES…WILL RANGE FROM 105 TO 108 THIS AFTERNOON.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A HEAT ADVISORY MEANS THAT A PERIOD OF HOT TEMPERATURES IS EXPECTED. TAKE EXTRA PRECAUTIONS IF YOU WORK OR SPEND TIME OUTSIDE. WHEN POSSIBLE…RESCHEDULE STRENUOUS ACTIVITIES TO EARLY MORNING OR EVENING. KNOW THE SIGNS AND SYMPTOMS OF HEAT EXHAUSTION AND HEAT STROKE. WEAR LIGHT WEIGHT AND LOOSE FITTING CLOTHING WHEN POSSIBLE AND DRINK PLENTY OF WATER.

TO REDUCE RISK DURING OUTDOOR WORK THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION RECOMMENDS SCHEDULING FREQUENT REST BREAKS IN SHADED OR AIR CONDITIONED ENVIRONMENTS. ANYONE OVERCOME BY HEAT SHOULD BE MOVED TO A COOL AND SHADED LOCATION. HEAT STROKE IS AN EMERGENCY…CALL 9 1 1.

Send us your weather pictures! Send them to weather@wvuatv.com. Also, look us up on facebook and twitter. Like us on facebook by searching facebook.com/wvuaweather or WVUA-TV Weather. You can find us on twitter by searching weather@wvuatv.com or WVUA-TV Weather. Great way to get weather updates! Plus, facebook is a great way to send us weather pictures. Simply tag us!

Join us live on WVUA-TV weekdays at 4, 5, 6 and 10 pm and weekends at 10pm for the very latest on your news, weather and sports.

Richard Scott

WVUA Chief Meteorologist

rscott@wvuatv.com

source: NWS Birmingham