WTNT43 KNHC 221503
TCDAT3
TROPICAL DEPRESSION THREE DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL032010
1100 AM EDT THU JUL 22 2010
 
THE TROPICAL WAVE/DISTURBANCE THAT NHC HAS BEEN TRACKING FOR THE
PAST SEVERAL DAYS ACROSS THE ATLANTIC HAS DEVELOPED A SURFACE
CIRCULATION AND ENOUGH ORGANIZED CONVECTION TO BE CLASSIFIED AS A
TROPICAL DEPRESSION. THE DEPRESSION IS SHEARED AT THIS TIME AND ITS
CENTER IS LOCATED ON THE SOUTHWEST SIDE OF A CYCLONICALLY CURVED
CONVECTIVE BAND. THE SHEAR APPEARS TO BE RELAXING A
LITTLE...HOWEVER...AS INDICATED BY THE MOTION OF THE HIGH CLOUDS ON
HIGH RESOLUTION IMAGES. THE CYCLONE IS STILL INTERACTING WITH A
STRONG WESTWARD-MOVING UPPER LOW TO THE WEST. THIS PATTERN WOULD
ONLY ALLOW THE DEPRESSION TO STRENGTHEN A LITTLE AS INDICATED IN
THE OFFICIAL FORECAST...BUT THIS FORECAST IS UNCERTAIN. IN FACT...
NONE OF THE MODELS SHOW SIGNIFICANT INTENSIFICATION.
 
BECAUSE THE CENTER JUST FORMED...THE INITIAL MOTION IS UNCERTAIN.
THE BEST ESTIMATE IS TOWARD THE WEST-NORTHWEST OR 295 DEGREES AT 13
KNOTS. GLOBAL MODELS FORECAST A WELL-ESTABLISHED SUBTROPICAL RIDGE
EXTENDING FROM THE ATLANTIC WESTWARD ACROSS THE SOUTHERN UNITED
STATES.  THIS STEERING PATTERN SHOULD KEEP THE CYCLONE ON A GENERAL
WEST-NORTHWESTWARD TRACK THROUGH 3 TO 4 DAYS ACROSS THE FLORIDA
STRAITS AND THE KEYS AND THEN INTO THE GULF OF MEXICO. BECAUSE THE
RIDGE IS FORECAST TO STRENGTHEN...THE CYCLONE SHOULD BEGIN TO
INCREASE ITS FORWARD SPEED. THE TRACK GUIDANCE IS TIGHTLY CLUSTERED
THROUGH 4 OR 5 DAYS...ALTHOUGH SOME MODELS WEAKEN THE CYCLONE
EARLIER.
 
AN AIR FORCE PLANE WILL BE IN THE AREA THIS AFTERNOON AND WILL HELP
TO DETERMINE IF THE SYSTEM HAS BECOME A TROPICAL STORM.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/1500Z 21.9N  75.0W    30 KT
 12HR VT     23/0000Z 22.6N  76.8W    35 KT
 24HR VT     23/1200Z 23.8N  80.0W    40 KT
 36HR VT     24/0000Z 25.0N  83.2W    40 KT
 48HR VT     24/1200Z 26.0N  86.5W    40 KT
 72HR VT     25/1200Z 28.0N  91.5W    45 KT
 96HR VT     26/1200Z 31.0N  94.0W    25 KT...INLAND
120HR VT     27/1200Z 33.0N  95.0W    20 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER AVILA/ROBERTS
 

WTNT43 KNHC 222032
TCDAT3
TROPICAL DEPRESSION THREE DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL032010
500 PM EDT THU JUL 22 2010
 
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.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/2100Z 22.7N  75.4W    30 KT
 12HR VT     23/0600Z 23.8N  77.5W    35 KT
 24HR VT     23/1800Z 24.5N  80.5W    45 KT
 36HR VT     24/0600Z 25.5N  83.7W    45 KT
 48HR VT     24/1800Z 26.5N  86.5W    45 KT
 72HR VT     25/1800Z 29.0N  91.0W    45 KT
 96HR VT     26/1800Z 32.5N  93.0W    25 KT...INLAND
120HR VT     27/1800Z 34.5N  93.0W    20 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER AVILA/ROBERTS
 

