[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 232337
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI MAY 23 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE
AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING
INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL
ANALYSIS...WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

A WELL DEFINED TROPICAL WAVE IS ALONG 28W S OF 12N MOVING W
10-15 KT. A 1010 MB LOW IS NEAR 7N28W ALONG THE WAVE AXIS.
PRONOUNCED LOW-LEVEL TURNING IS APPARENT ON SATELLITE IMAGERY
AND GFS MODEL GUIDANCE SHOWS LOW-MID LEVEL CYCLONIC CURVATURE
WHICH IS HELPING TO ENHANCE SCATTERED SHOWERS AND ISOLATED TSTMS
CONFINED TO AN AREA N OF THE LOW CENTER FROM 8N-10N BETWEEN
26W-30W.

A WEAK TROPICAL WAVE IS ALONG 60W S OF 12N MOVING W 10 KT. THIS
WAVE CONTINUES TO BE FAIRLY STRAIGHTFORWARD TO TRACK WITH A
SMALL NORTHWARD MOISTURE BULGE EVIDENT ON THE MIMIC-TPW
ANIMATION FROM CIMSS. TSTM ACTIVITY IS MAINLY INLAND OVER N
GUYANA AND NE VENEZUELA...BUT SCATTERED SHOWERS ARE POSSIBLE
WITHIN 180 NM OF THE WAVE AXIS.

A TROPICAL WAVE IS OVER E PORTIONS OF CENTRAL AMERICA ALONG 84W
S OF 17N MOVING W 10 KT. THE WAVE IS MOVING VERY SLOWLY WESTWARD
AND HAS BECOME DIFFICULT TO TRACK AS IT IS EMBEDDED IN STRONG
LOW-LEVEL SW WINDS. LOW-LEVEL CONVERGENCE COMBINED WITH UPPER
DIFFLUENCE IS PRODUCING SCATTERED SHOWERS AND TSTMS ACROSS
COASTAL PANAMA...COSTA RICA AND NICARAGUA IN THE SW CARIBBEAN
SEA.

..THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N10W 5N16W 6N24W 5N31W 3N35W 3N52W.
SCATTERED MODERATE TO STRONG CONVECTION IS MOVING OFF THE W
AFRICAN COAST FROM 5N-11N BETWEEN 10W-15W. SCATTERED MODERATE TO
ISOLATED STRONG CONVECTION IS FROM EQ-2N BETWEEN THE PRIME
MERIDIAN AND 2N. SIMILAR CONVECTION IS FROM 2N-4N BETWEEN
11W-13W AND FROM 5N-7N BETWEEN 15W-17W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY SHOWS A LARGE AREA OF DRY AIR ALOFT
SPREADING NE BY STRONG SW FLOW...MOST PRONOUNCED W OF 88W.
HOWEVER...A WEAK SHORTWAVE OVER ALABAMA IS HELPING TO AID IN
PRODUCING SCATTERED SHOWERS AND TSTMS IN THE NE GULF WATERS
CONCENTRATED MAINLY ALONG THE COASTAL WRN HALF OF THE FLORIDA
PANHANDLE. THIS ACTIVITY WILL SKIRT ACROSS N FLORIDA THIS
EVENING INTO SAT. THE REMAINDER OF THE GULF IS DOMINATED BY FAIR
WEATHER...THOUGH SATELLITE IMAGES SHOW AN AREA OF HAZE IN THE E
BAY OF CAMPECHE AND A SLIGHTLY LESS DENSE AREA OVER THE
REMAINDER OF THE W GULF FROM FIRES ON THE YUCATAN PENINSULA AND
OTHER PORTIONS OF MEXICO. A BACK DOOR TYPE COLD FRONT IS
EXPECTED TO SWEEP THROUGH FLORIDA AND THE E GULF SUN AND
MON...COOLING TEMPS ONLY SLIGHTLY BUT ALLOWING NOTICEABLY DRIER
AIR TO FILTER INTO THE REGION.

CARIBBEAN SEA...
CONVECTIVE ACTIVITY IS CONFINED TO THE FAR W/SW PORTION OF THE
BASIN NEAR AND OVER THE NICARAGUA AND HONDURAS COASTS FROM
11N-17N BETWEEN 83W-88W. THESE SCATTERED SHOWERS AND TSTMS ARE
ASSOCIATED WITH UPPER DIFFLUENT FLOW AND AIDED BY A SLOW MOVING
TROPICAL WAVE ALONG 84W. ELSEWHERE SCATTERED LOW-LEVEL CLOUD BAND
EXTENDS ACROSS THE N LEEWARD ISLANDS...PUERTO RICO AND
HISPANIOLA CREATING SHOWERS WITHIN 60 NM OF THE ISLANDS. THE
REMAINDER OF THE CARIBBEAN SEA IS EXPERIENCING MAINLY FAIR
WEATHER DUE TO A STABLE MID TO UPPER ENVIRONMENT...SUPPORTED
BY AN UPPER HIGH JUST S OF CENTRAL CUBA AND AN UPPER LOW OVER NW
VENEZUELA. THE DRIEST AIR IS LOCATED IN A CONFLUENT ZONE
BETWEEN 67W-79W. A WEAK TROPICAL WAVE MAY INCREASE LOW-LEVEL
MOISTURE ACROSS THE FAR S WINDWARD ISLANDS AND EXTREME SE
CARIBBEAN SEA WATERS SAT.

ATLANTIC OCEAN...
STRONG UPPER W TO NW FLOW LIES OVER THE W ATLC BETWEEN AN UPPER
HIGH OVER THE N CARIBBEAN AND A DEEP LAYER LOW NEAR NOVA SCOTIA.
THIS PATTERN IS PRODUCING AND TRANSPORTING A SWATH OF CLOUDINESS
N OF 25N W OF 50W. SCATTERED SHOWERS AND TSTMS ARE CONFINED TO A
REGION IN AN UPPER DIFFLUENT ZONE WITHIN 150 NM SE OF A COLD
FRONT WHICH ENTERS THE AREA NEAR 32N58W TO 29N69W. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE ALSO ACROSS THE W ATLC FROM THE
CENTRAL BAHAMAS TO NORTH OF THE DISCUSSION AREA BETWEEN 74W-80W
AHEAD OF A WEAKENING 1013 MB SURFACE LOW PRESSURE MOVING OFF THE
CAROLINA COAST. E OF 50W...A LARGE UPPER LOW IS THE DOMINATE
FEATURE ALOFT SPINNING NEAR 27N40W WITH TROUGHING STRETCHING S
TO THE EQUATOR NEAR 40W. MAINLY HIGH LEVEL CLOUDS ARE SCATTERED
ACROSS THE E ATLC TRANSPORTED BY STRONG SW UPPER FLOW BETWEEN
THE UPPER LOW/TROUGH AND AN UPPER RIDGE OVER W AFRICA.

AT THE SURFACE...BESIDES FOR THE AFOREMENTIONED COLD FRONT THAT
CLIPS THE DISCUSSION ZONE AND A COUPLE OF LOW-LATITUDE TROPICAL
WAVES...HIGH PRESSURE RIDGING IS IN PLACE ACROSS A VAST MAJORITY
OF THE ATLC ANCHORED BY A 1026 MB HIGH SW OF THE AZORES NEAR
35N37W.

$$
HUFFMAN




This weather bulletin was brought to you by:
www.nashvilleweather.net