More Bonnie – 10 PM

AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT EARLIER FOUND 1500 FT FLIGHT-LEVEL WINDS OF 43 KT IN THE NORTHEASTERN QUADRANT…AND BELIEVABLE SFMR WINDS OF 35-39 KT.  BASED ON THIS
TROPICAL DEPRESSION THREE WAS UPGRADED TO TROPICAL STORM BONNIE.  SATELLITE IMAGERY SINCE THAT TIME SUGGESTS LITTLE CHANGE IN STRENGTH…WITH SOUTHERLY VERTICAL WIND SHEAR DISPLACING THE
CONVECTION TO THE NORTH OF THE LOW-LEVEL CENTER.  THE NEXT AIRCRAFT IS SCHEDULED TO REACH BOONIE AROUND 06Z.

THE CENTER HAS BEEN WOBBLING NORTHWESTWARD DURING THE PAST SEVERAL HOURS…WITH THE INITIAL MOTION A SOMEWHAT UNCERTAIN 305/12.  BONNIE IS ON THE EAST SIDE OF A LARGE MID/UPPER-LEVEL LOW OVER THE EASTERN GULF OF MEXICO AND SOUTH OF A DEEP-LAYER RIDGE OVER THE
SOUTHEASTERN UNITED STATES.  AS THE UPPER LOW MOVES WESTWARD… BONNIE SHOULD TURN WEST-NORTHWESTWARD IN RESPONSE TO THE FLOW AROUND THE RIDGE…WITH THE TRACK GUIDANCE MODELS IN GOOD AGREEMENT ON THIS SCENARIO THROUGH 72 HR.  THIS MOTION SHOULD BRING THE
CENTER ACROSS THE FLORIDA PENINSULA OR KEYS ON FRIDAY…AND NEAR OR OVER THE NORTHERN GULF COAST IN 60-72 HR.  AFTER THAT…THE CYCLONE IS EXPECTED TO MOVE NORTHWARD AROUND THE WESTERN END OF THE RIDGE.  THE NEW FORECAST TRACK HAS BEEN SHIFTED NORTHWARD DURING THE FIRST
72 HR BASED ON THE CURRENT POSITION AND MOTION.  HOWEVER…IT LIES SOUTH OF THE MODEL CONSENSUS THROUGH THE FIRST 48 HR AND SOME ADDITIONAL NORTHWARD ADJUSTMENT MAY BE NECESSARY LATER.

IN ADDITION TO THE SOUTHERLY SHEAR…BONNIE IS CURRENTLY IN AN AREA OF UPPER-LEVEL CONFLUENCE ON THE EASTERN SIDE OF THE GULF UPPER LOW.  THIS IS A LESS THAN IDEAL ENVIRONMENT FOR STRENGTHENING…AND THE INTENSITY GUIDANCE FORECASTS ONLY MODEST INTENSIFICATION BEFORE
BONNIE REACHES FLORIDA.  THE FORECAST HAS BECOME MORE PROBLEMATIC OVER THE GULF OF MEXICO.  THE SHIPS AND LGEM MODELS…PERHAPS RESPONDING TO SOME DECREASE IN THE SHEAR…NOW FORECAST BONNIE TOPEAK NEAR 60 KT OVER THE GULF.  ON THE OTHER HAND…THE GFDL…GFDN…AND HWRF DO NOT FORECAST SIGNIFICANT STRENGTHENING… AND NEITHER DO THE GLOBAL MODELS.  SINCE THE LARGE UPPER LOW IS FORECAST TO DOMINATE THE NORTHERN GULF THROUGH 48 HR…THE INTENSITY FORECAST WILL LEAN IN FAVOR OF THE DYNAMICAL MODELS.  THE NEW INTENSITY FORECAST IS THE SAME AS THE PREVIOUS FORECAST.

WVUA Meteorologist Richard Scott

Advertisements

Hello Bonnie – 5:15 PM

…DEPRESSION BECOMES TROPICAL STORM BONNIE…

DATA FROM AN AIR FORCE HURRICANE HUNTER RECONNAISSANCE AIRCRAFT DURING THE PAST HOUR INDICATE THAT SURFACE WINDS ASSOCIATED WITH THE DEPRESSION HAVE INCREASED TO 40 MPH…65 KM/HR…AND THAT THE DEPRESSION HAS BECOME A TROPICAL STORM.

SUMMARY OF 615 PM EDT…2215 UTC…INFORMATION
————————————————–
LOCATION…22.9N 75.4W
ABOUT 200 MI…320 KM SE OF NASSAU
ABOUT 415 MI…670 KM ESE OF KEY WEST FLORIDA
MAXIMUM SUSTAINED WINDS…40 MPH…65 KM/HR
PRESENT MOVEMENT…NW OR 315 DEGREES AT 14 MPH…22 KM/HR
MINIMUM CENTRAL PRESSURE…1005 MB…29.68 INCHES

WVUA Meteorologist Richard Scott

Thursday Afternoon Weather Update – 4:07 PM

A good Thursday to you! It’s been another day of hot, hazy and humid conditions. Temperatures have topped out in the upper 90 to 100 degree range, with heat index values above 105 in spots. There’s not much rain to cool us off today, but rain is in the forecast later in the weekend and early next week. Between now and the weekend, our weather will stay very hot and dry. Temperatures could top 100 degrees for our Friday afternoon, with a heat index of 108.

As we make our weekend plans, keep in mind that storms are possible on Sunday. Saturday is looking mostly dry and very hot. Temperatures could easily top 98 degrees. A stray shower or storm is possible, but rain chances go up on Sunday and Monday. This all depends on our tropical activity. Tropical Depression # 3 developed this morning, and is forecasted to become a tropical storm tomorrow. The latest track from the National Hurricane Center has this system moving in the general direction of the Louisiana coastline. A ridge of high pressure is expected to shift eastward over the weekend and early next week, which could steer it closer to the central gulf coast. We’ll continue to keep an eye to the tropics and will update you as it approaches. Since data is still sketchy on the track and strength, uncertainties still exist in the forecast. As of now, I have a 40% chance of rain in the forecast on Sunday and Monday, with the best chance being south of Tuscaloosa.

Tropical moisture sticks around through early next week, with a few storms possible each afternoon. The ridge will build back in by the mid portion of next week, which will bring our rain chances down to 20%. Be sure to join us on WVUA-TV for more on your local weather forecast.

Richard Scott
WVUA Meteorologist

Tropical Depression # 3

AN AIR FORCE RECONNAISSANCE PLANE HAS BEEN INVESTIGATING THE DEPRESSION AND FOUND A BROAD CIRCULATION WITH PEAK WINDS AROUND 30 KNOTS AND A MINIMUM PRESSURE NEAR 1006 MB. THE CLOUD PATTERN HAS NOT BECOME ANY BETTER ORGANZIED THAN EARLIER TODAY WITH THE CENTER NOW ON THE SOUTHERN PORTION OF THE CONVECTION DUE TO SOME SHEAR. THE OUTFLOW IS BECOMING ESTABLISHED IN ALL QUADRANTS EXCEPT TO THE SOUTHWEST WHERE THE UPPER LOW IS LOCATED. INITIAL INTENSITY IS KEPT AT 30 KNOTS BUT ONLY A SMALL RELAXATION OF THE SHEAR…AS EXPECTED…WILL RESULT IN SOME INTENSIFICATION. NONE OF THE GUIDANCE MODELS SHOW LARGE INCREASES IN STRENGTH…PERHAPS DUE TO
THE PROXIMITY OF THE DEPRESSION TO THE STRONG UPPER LOW. THE OFFICIAL FORECAST IS GENEROUS COMPARED TO THE DYNAMICAL GUIDANCE BUT IS CLOSE TO THE SHIPS AND LGEM MODELS.

THE OVERALL CIRCULATION HAS MOVED A LITTLE TO THE NORTHWEST AROUND AN UPPER-LOW OVER FLORIDA DURING THE PAST FEW HOURS. THE BEST ESTIMATE OF THE INITIAL MOTION IS 310 DEGREES AT 12 KNOTS.
HOWEVER…AS THE UPPER LOW MOVES TO THE WEST AS INDICATED BY MOST OF THE GLOBAL MODELS…THE DEPRESSION WILL BECOME EMBEDDED WITHIN A DEEP EASTERLY FLOW AND SHOULD BEGIN TO MOVE MORE TO THE WEST-NORTHWEST WITH AN INCREASE IN FORWARD SPEED. THE TRACK GUIDANCE IS IN REMARKABLY GOOD AGREEMENT…BRINGING THE CYCLONE ACROSS THE FLORIDA STRAITS AND ACROSS THE GULF OF MEXICO…AND SO DOES THE OFFICIAL FORECAST.

WVUA Meteorologist Richard Scott