[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 190601
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN JUL 19 2015

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 04N35W TO 17N31W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH A BROAD 700 MB TROUGH BETWEEN 26W-
37W. SSMI TPW INDICATES MODERATE MOISTURE S OF 12N ALONG THE
WAVE. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM
05N-09N BETWEEN 35W-39W.

TROPICAL WAVE EXTENDS FROM 08N46W TO 20N46W MOVING W AT 20 KT.
THIS WAVE ALSO COINCIDES WITH A BROAD 700 MB TROUGH BETWEEN 44W-
50W. SSMI TPW INDICATES A POLEWARD SURGE OF HIGH MOISTURE ALONG
THE WAVE AXIS. ISOLATED MODERATE CONVECTION IS FROM 09N-16N
BETWEEN 45W-52W.

TROPICAL WAVE EXTENDS FROM 05N56W TO 21N52W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH A TILTED 700 MB TROUGH BETWEEN 54W-
61W. DRY AIR AND SAHARAN DUST IS EVIDENT IN THE ENVIRONMENT OF
THE WAVE...INHIBITING CONVECTION ALONG THE WAVE.

TROPICAL WAVE HAS MOVED INLAND OVER THE YUCATAN TO GUATEMALA AND
OVER THE EASTERN PACIFIC. PLEASE REFER TO THE PACIFIC TROPICAL
WEATHER DISCUSSION AT MIATWOEP FOR ADDITIONAL DETAILS.

...ITCZ/MONSOON TROUGH...
THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N35W TO
05N51W. ASIDE FROM CONVECTION ASSOCIATED WITH THE EASTERNMOST
TROPICAL WAVE...WIDELY SCATTERED MODERATE CONVECTION IS FROM THE
EQUATOR TO 08N BETWEEN 37W AND 48W.

...DISCUSSION...

GULF OF MEXICO...
NORTHEASTERLY FLOW ALOFT PERSISTS ACROSS THE MAJORITY OF THE
GULF AROUND RIDGING THAT EXTENDS FROM THE TX COAST TO THE TN
VALLEY. A WEAKNESS IN THIS RIDGE OVER THE NE GULF CONTINUES TO
SUPPORT A SURFACE TROUGH THAT EXTENDS FROM THE FL PANHANDLE NEAR
TALLAHASSEE TO 30N85W TO 28N87W TO 27N90W. SCATTERED SHOWERS ARE
OCCURRING WITHIN 150 NM OF THE TROUGH AXIS. ADDITIONAL SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ARE OVER THE SE GULF FROM 24N
TO 28N E OF 86W AND ARE PRIMARILY BEING DRIVEN BY WEAK
PERTURBATIONS IN THE NE FLOW ALOFT AND DEEP TROPICAL MOISTURE IN
PLACE ACROSS THE AREA. SURFACE RIDGING ANCHORED BY A 1018 MB
HIGH CENTERED NEAR 27N91W SUPPORTS GENERALLY FAIR WEATHER ACROSS
THE REMAINDER OF THE GULF BASIN. A DIURNALLY DRIVEN SURFACE
TROUGH IS ALONG THE WESTERN COAST OF THE YUCATAN FROM 21N90W TO
18N91W. CURRENTLY THERE IS NO DEEP CONVECTION NOTED WITH THIS
TROUGH. OVER THE NEXT 24 HOURS SURFACE TROUGHING IS EXPECTED TO
PERSIST OVER THE NE GULF WITH ONGOING CONVECTION POSSIBLE OVER
THAT PORTION OF THE BASIN. PERIODIC CONVECTION WILL BE POSSIBLE
OVER THE SW GULF IN THE VICINITY OF THE YUCATAN DRIVEN SURFACE
TROUGH.

CARIBBEAN SEA...
NORTHEASTERLY FLOW ALOFT COVERS THE NW CARIBBEAN AROUND THE
PERIPHERY OF THE TX UPPER LEVEL RIDGE...WITH S TO SE FLOW ALOFT
OVER THE EASTERN CARIBBEAN AROUND A CENTRAL TROPICAL ATLC UPPER
LEVEL RIDGE. IN BETWEEN...TROUGHING THAT EXTENDS FROM THE W ATLC
TO THE SW CARIBBEAN SUPPORTS A BROAD AREA OF WEAK UPPER LEVEL
DIFFLUENCE THAT SPANS FROM CUBA AND HISPANIOLA SW TO NICARAGUA
AND THE SW CARIBBEAN. THIS DIFFLUENCE COMBINED WITH MODERATE TO
HIGH ATMOSPHERIC MOISTURE SUPPORTS SCATTERED THUNDERSTORMS FROM
18N TO 23N BETWEEN 72W AND 85W...INCLUDING THE CAYMAN ISLANDS.
SCATTERED MODERATE CONVECTION IS S OF 15N W OF 75W OVER THE SW
CARIBBEAN. 15 TO 20 KT TRADE WINDS COVER THE MAJORITY OF THE
CARIBBEAN WITH A SMALL AREA OF WINDS TO 25 KT N OF THE COLOMBIA
COAST...WHERE THE PRESSURE GRADIENT IS TIGHTEST BETWEEN ATLC
HIGH PRESSURE AND LOWER PRESSURE OVER COLOMBIA. OVER THE NEXT 24
HOURS CONVECTION WILL BE POSSIBLE OVER THE SW AND WESTERN
CARIBBEAN UNDER DIFFLUENT FLOW IN THE PRESENCE OF DEEP
MOISTURE.

...HISPANIOLA...
DIFFLUENCE ALOFT IS SUPPORTING ISOLATED THUNDERSTORMS OVER THE
EXTREME W PORTION OF HAITI THIS MORNING. THESE STORMS SHOULD
DIMINISH LATER THIS MORNING. DRY IN PLACE IS EXPECTED TO INHIBIT
SHOWER AND THUNDERSTORM ACTIVITY ELSEWHERE OVER THE ISLAND
THROUGH TONIGHT.

ATLANTIC OCEAN...
UPPER LEVEL RIDGING EXTENDS FROM THE US INTO THE W ATLC WITH MID
TO UPPER LEVEL DISTURBANCES EVIDENT IN WATER VAPOR IMAGERY
ROUNDING THE PERIPHERY OF THE RIDGING W OF 75W AROUND
30N...SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
FROM 29N TO 31N BETWEEN 74W AND 80W. A PAIR OF UPPER LOWS
CENTERED NEAR 29N68W AND 28N57W SUPPORT ISOLATED THUNDERSTORMS N
OF 24N BETWEEN 54W AND 72W. A SURFACE TROUGH IS A REFLECTION OF
THE EASTERNMOST UPPER LOW AND EXTENDS FROM 30N55W TO 27N60W TO
25N65W. THIS TROUGH ALSO ACTS AS A WEAKNESS IN THE SUBTROPICAL
RIDGE WITH A 1021 MB HIGH CENTERED NEAR 29N65W. A 1025 MB HIGH
CENTERED NEAR 29N40W ANCHORS RIDGING THAT EXTENDS ACROSS THE
CENTRAL AND EASTERN SUBTROPICAL ATLC. THREE TROPICAL WAVES ARE
OVER THE TROPICAL NORTHERN ATLC. PLEASE REFER TO THE TROPICAL
WAVES SECTION FOR MORE DETAILS. EXPECT CONVECTION TO CONTINUE
ALONG 30N OFF THE FL COAST OVER THE NEXT 24 HOURS.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

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