Caribbean - Central America Weather

[Macrocane]

Yesterday was the rainiest day in El Salvador since October 16, 2011. The highest accumulation was registered in Conchagua with 172 mm/6.77 inches. Other high rainfall amounts were:

Perquín 128 mm/5.04 inches
Montecristo 116 mm/4.57 inches
Concepción de Oriente 95 mm/3.74 inches
La Unión 84.6 mm/3.33 inches
El Pacayal 83.4 mm/3.28 inches

A map with yesterday rainfall:

[cycloneye]

Good morning. Drier weather is expected today thru Monday but a trough will increase the showers on Tuesday. Invest 98L may arriv by next weekend bringing bad weather to the islands so stay tuned.



AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
434 AM AST SUN SEP 8 2013

.SYNOPSIS...UPPER LEVEL RIDGE WILL HOLD THROUGH EARLY MON THEN
YIELD TO RETROGRESSING TUTT OVR THE CNTRL ATLC. TUTT WILL REACH PR
TUE. MID-UPPER LEVEL RIDGE WILL THEN BUILD THU. A WEAK AREA OF LOW
PRES WILL APPROACH THE AREA NEXT WEEKEND.

&&

.DISCUSSION...MCS CONTINUES TO WEAKEN THIS MORNING WITH STRATIFORM
LIGHT RAIN AFFECTING MAINLAND PR AND OUTFLOW BDRY MOVING EWD OVR
THE ERN COASTAL WATERS AHEAD OF MAIN CONVECTIVE LINE. FOR
TODAY...MAINLY CLOUDY SKIES AS MODEL SOUNDINGS SHOW ONION-SHAPED
LOW LEVEL TEMP/DEWPOINT PROFILES INDICATIVE OF DOWNDRAFTS FROM MCS
AND WARMING AND DRYING EFFECTS OF SUBSIDENCE.

MUCH DRIER AND STABLE AIR WILL ADVECT INTO THE AREA FROM THE EAST
TONIGHT AS SAL ARRIVES. 08/0145Z MODIS TERRA DUST RGB PRODUCT
(12-11 MICRON CHANNEL DIFFERENCING) SHOWS LEADING EDGE OF SAHARAN
DUST APPROACHING BARBADOS AND THE LESSER ANTILLES AND THAT SHOULD
BE OVER PR BY MON. OVERALL...VERY DRY CONDITIONS ON MON.

UNUSUALLY DEEP TUTT OVR THE CNTRL ATLC WILL AMPLIFY AND RETROGRESS
TOWARD PR BY TUE. MODELS INDICATE THIS BEING A PRETTY DEEP FEATURE
AS IT REFLECTS TO 500 MB WITH 200 MB HEIGHTS BELOW THE 25TH
PERCENTILE FOR THIS TIME OF THE YEAR AND COOL MID-LEVEL H5 TEMPS
CLOSE TO TWO STANDARD DEVIATIONS BELOW NORMAL. WHILE MOISTURE
SEEMS SOMEWHAT LIMITED VERY UNSTABLE CONDITIONS SHOULD COMPENSATE
AND AID IN THE DEVELOPMENT OF STRONG CONVECTION AS IT INTERACTS
WITH SAL. BETTER MOISTURE IS FCST BEGINNING THU AS SAL DEPARTS.

ANOTHER FEATURE OF INTEREST IS FORMER INVEST 98L LOCATED NEAR
16.4N AND 36.5W. MODELS SHOW THIS LOW PRES SYSTEM MOVING WNW AND
THEN DIVING WSW REACHING PR OVR THE WEEKEND. WHILE THE ENVIRONMENT
DOES NOT LOOK FAVORABLE FOR TC DEVELOPMENT DUE TO MID-UPPER LEVEL
DRY AIR AHEAD OF IT MODELS SHOW FEATURE HOLDING TOGETHER AND
ACTUALLY STRENGTHENING SOME AS IT REACHES THE LESSER ANTILLES FRI.
EXPECT THIS SYSTEM TO BRING SOME ACTIVE WX NEXT WEEKEND.

&&

.AVIATION...AREAS MVFR CIG LEFT OVER FM OVERNIGHT SHRA/TSRA WL GRDLY
IMPRV BEFORE SUNRISE. TIST/TISX MIGHT STILL GET MVFR IN TSRA OR BRF
IFR THIS MRNG IF CONVECTION CONT MOVG E FM VIEQUES/CULEBRA. WL
INCLUDE PDS MVFR ACCORDINGLY. OTHW SHRA/TSRA TO BE ISOLD TDY XCPT
SCT NW PR. SAHARAN AIR WL BGN TO AFFECT AREA LATE TDY...PSBL FALSE
CIGS FOR TIST/TISX ASOS ON SAT. WINDS SFC-FL100 S TO SE 10-18 KT
BCMG ESE NR 10 KT BY SAT AFT.


&&

.MARINE...SEAS 2-4 FT AND WINDS UP 20 KT. SCT TSRA MAINLY ERN
WATERS. SEAS BUILDING UP TO 6 FT BY THE END OF THE WORK WEEK IN
ENE SWELLS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 79 90 79 / 10 10 20 0
STT 82 78 89 81 / 20 10 10 10

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
300 PM AST SUN SEP 8 2013

.SYNOPSIS...TUTT LOW OVER THE CENTRAL ATLANTIC NORTHEAST OF THE
REGION WILL MOVE SOUTHWESTWARD AND THEN NORTHWESTWARD OVER THE LOCAL
ISLANDS BY TUESDAY AND WEDNESDAY...INCREASING THE INSTABILITY ACROSS
THE LOCAL ISLANDS. A WEEK LOW PRESSURE CENTER ASSOCIATED WITH A
TROPICAL WAVE IS EXPECTED TO APPROACH THE REGION BY THE UPCOMING
WEEKEND.

&&

.DISCUSSION...LATEST SATELLITES IMAGES THIS AFTERNOON DEPICTED A
LARGE AREA OF MID TO HIGH LEVEL CLOUDINESS ACROSS THE LOCAL ISLANDS
AND THE SURROUNDING WATERS. THIS CLOUDINESS WAS ASSOCIATED WITH THE
REMNANTS OF TROPICAL STORM GABRIELLE LOCATED NORTH OF HISPANIOLA.
THIS CLOUDINESS INHIBITED THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE LOCAL ISLANDS SO FAR THIS AFTERNOON. THE
DOPPLER WEATHER RADAR DETECTED ONLY ISOLATED SHOWERS ACROSS THE
REGION SO FAR THIS AFTERNOON. A GENERALLY DRY TREND IS EXPECTED TO
CONTINUE ACROSS THE REGION FOR THE NEXT FEW DAYS AS THE REMNANTS OF
GABRIELLE MOVE NORTHWARD AND WELL AWAY FROM THE FORECAST AREA. AS
THE WIND FLOW TURN MORE FROM THE EAST EARLY IN THE WEEK THE WEATHER
ACROSS THE REGION WILL RETURN TO THE TYPICAL OR NORMAL SUMMER
WEATHER PATTERN OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER WESTERN
AND INTERIOR SECTIONS OF PUERTO RICO. A TUTT LOW ACROSS THE CENTRAL
ATLANTIC EAST NORTHEAST OF PUERTO RICO IS EXPECTED TO AMPLIFY
SOUTHWESTWARD AND THEN NORTHWESTWARD ACROSS THE EASTERN AND
NORTHEASTERN CARIBBEAN LATE TUESDAY/EARLY WEDNESDAY...INCREASING THE
INSTABILITY OVER THE LOCAL ISLANDS. THE GFS MODEL GUIDANCE SUGGESTS
THAT A WEAK LOW PRESSURE CENTER ASSOCIATED WITH A TROPICAL WAVE
ACROSS THE EASTERN ATLANTIC WILL MOVE CLOSE TO THE REGION BY THE
UPCOMING WEEKEND...INCREASING AGAIN THE CHANCES OF SHOWERS AND
THUNDERSTORMS.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED ACROSS THE LOCAL FLYING
AREA DURING THE NEXT 24 HOURS.

&&

.MARINE...MARINE CONDITIONS WILL REMAIN RATHER QUIET FOR THIS
TIME OF THE YEAR WITH SEAS OF 3 TO 5 FT AND WINDS OF 16 KT OR
LESS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 80 89 / 10 20 0 30
STT 79 89 79 90 / 10 10 10 50

[cycloneye]

Good morning. Dry weather will prevail today with only widely scattered showers.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
412 AM AST MON SEP 9 2013

.SYNOPSIS...MID-UPPER LEVEL RIDGE WILL YIELD TO RETROGRESSING TUTT
EAST OF THE LESSER ANTILLES. NARROW UPPER LEVEL RIDGE WILL BUILD
THU AND HOLD THRU THE END OF THE WEEKEND.

&&

.DISCUSSION...SAL WILL ENTER THE NORTHEAST CARIB LATER THIS
MORNING WITH A LITTLE BIT OF DUST HAZE. HOT TODAY WITH TEMPS IN
THE MID 90S. DEEP TUTT EAST OF THE LESSER ANTILLES WILL ENTER THE
SE CARIB LATE TONIGHT AND WILL HELP DESTABILIZE ATMOSPHERE TUE.
SOME STRONG CONVECTION POSSIBLE TUE AS TUTT INTERACTS WITH SAL.

MOISTURE DEEPENS THU AS WEAK AREA OF LOW PRES NEAR 42W (FORMER
INVEST 98L) APPROACHES THE AREA. MODELS SHOW THIS FEATURE HOLDING
TOGETHER AS IT MOVES ACROSS THE ATLC ALTHOUGH TC DEVELOPMENT IS
NOT EXPECTED DUE TO MID-UPPER LEVEL DRY AIR AHEAD OF IT.
ANYWAY...SYSTEM COULD BRING SOME ACTIVE WX LATE IN THE WEEK.


&&

.AVIATION...VFR ALL TAFS THRU TONITE XCP IN SCT TSRA NW PR THIS AFT.
TIST TO LIKELY SHOW FALSE MVFR CIG AT TIMES THRU TUE MRNG DUE
SAHARAN DUST. WINDS SFC-FL100 SE 10-15 KT BCMG E 10-20 KT TONITE.

&&

.MARINE...SEAS 2-4 FT AND WINDS 10-15 KT. SCT TSRA/LIGHTNING
TUE-THU THE MAIN THREAT.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 80 89 80 / 20 0 40 40
STT 89 81 89 81 / 10 20 40 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
242 PM AST MON SEP 9 2013

.SYNOPSIS...UPPER LEVEL RIDGE ACROSS THE FORECAST AREA WILL CONTINUE
TO ERODE TONIGHT AND EARLY TUESDAY MORNING...AS TUTT MOVES WEST
TOWARD THE EASTERN AND CENTRAL CARIBBEAN. NARROW UPPER LEVEL RIDGE
WILL THEN BUILD LATE THURSDAY INTO FRIDAY...AND HOLD THRU THE END
OF THE WEEKEND.

&&

.DISCUSSION...A GENERALLY FAIR WEATHER PATTERN PREVAILED ACROSS THE
LOCAL ISLANDS TODAY...WITH VARIABLY CLOUDY SKIES AND LIMITED SHOWER
ACTIVITY. WINDS WERE LIGHT AND VARIABLE WITH COASTAL TEMPERATURE
IN THE LOW TO MID 90S. IN FACT...MAXIMUM TEMPERATURE AT THE LUIS
MUNOZ MARIN INTL AIRPORT WAS 94 DEGREES...THIS TIED PREVIOUS RECORD
SET BACK IN 2009 AND 1995. SATELLITE IMAGERY INDICATE TUTT EAST OF
THE LESSER ANTILLES...SPINNING TOWARD THE LOCAL AREA.

THE LOCAL ISLANDS WILL BECOME UNDER THE INFLUENCE OF AFOREMENTIONED
TUTT TONIGHT INTO TUESDAY. THIS FEATURE WILL INTERACT WITH PATCHES
OF LOW LEVEL MOISTURE AND LOCAL EFFECTS TO PRODUCE CLOUDINESS AND
SHOWERS WITH THUNDERSTORMS ACROSS PORTIONS OF THE LOCAL ISLANDS DURING
THE WORK WEEK. AS A TRADE WIND FLOW ESTABLISHES ACROSS THE EASTERN
CARIBBEAN TONIGHT...THE WEATHER PATTERN WILL INCLUDE PASSING SHOWERS
ACROSS THE EAST COASTAL SECTIONS OF THE ISLANDS DURING THE MORNING
HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY FOCUSED
ACROSS THE CORDILLERA CENTRAL AND WESTERN PUERTO RICO. SHOWER/THUNDERSTORM
INTENSITY AND COVERAGE WILL INCREASE WEDNESDAY AS TUTT MOVES INTO
THE CENTRAL CARIBBEAN...AND THURSDAY/FRIDAY AS MOISTURE DEEPENS
ACROSS THE AREA. NARROW UPPER LEVEL RIDGE WILL THEN BUILD BY THE
END OF THE WEEK.

&&

.AVIATION...VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE
FCST PERIOD. HOWEVER AFTER 10/17Z TSRA IS EXPECTED ACROSS THE
INTERIOR OF PR WITH MOUNTAIN OBS...VCTS EXPECTED OVER TJMZ AND TJBQ.
LOW LEVEL WINDS FROM THE SOUTHEAST AT LESS THAN 10 KTS BCMG EAST
TONIGHT.

&&

.MARINE...TRANQUIL MARINE CONDITIONS EXPECTED OVER THE NEXT FEW
DAYS...WITH SEAS OF UP TO 4 FEET AND WINDS 15 KNOTS OF LESS.

&&

.CLIMATE...A RECORD HIGH TEMPERATURE OF 94 DEGREES WAS SET AT LMM
INTL AIRPORT IN SAN JUAN/P.R. TODAY. THIS TIED THE OLD RECORD OF
94 SET BACK IN 2009 AND 1995.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 79 89 / 0 40 40 40
STT 81 89 81 89 / 20 40 30 30

[cycloneye]

Good morning. Scattered showers will move thru PR today as a trough passes by. Another period of rain is expected this weekend as Tropical Wave moves thru.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
428 AM AST TUE SEP 10 2013

.SYNOPSIS...TUTT OVR THE ERN CARIB WILL BECOME DOMINANT WX FEATURE
THROUGH WED. SUBTROPICAL RIDGE WILL THEN BUILD THU AND HOLD
THROUGH EARLY NEXT WEEK. WEAK LOW PRES ASSOCIATED WITH A TROPICAL
WAVE ALONG 47W WILL MOVE ACROSS THE ERN CARIB SAT.


&&

.DISCUSSION...MOISTURE WILL BE ON THE INCREASE TODAY AND IN
COMBINATION WITH MID LEVEL COOL ADVECTION AND AMPLE SUNSHINE
SHOULD AID IN THE DEVELOPMENT OF SCT AFTERNOON CONVECTION WHICH
MAY BECOME STRONG. STORM MOTION WILL ALSO BE QUITE FAST AROUND 20
KNOTS WHICH SHOULD FAVOR STRONG GUSTY WINDS. BELIEVE WILL SEE A
DECREASE IN AREAL CVRG AND INTENSITY OF CONVECTION WED AS MID
LEVELS WARM AND ATMOS DRIES OUT SOMEWHAT. MOISTURE INCREASES AGAIN
THU ON THE LEADING EDGE OF WEAK AREA OF LOW PRES ALONG 47W. MODELS
SEEM DEFICIENT WITH MOISTURE FIELD WITH THIS WAVE. LATEST BLENDED
TPW PRODUCT SHOWS PWATS OF 2.67 INCHES WITH THIS WAVE WHILE GFS
SHOWS 2.3 INCHES. EXPECT AN ACTIVE AFTERNOON THU WITH LOCALLY
HEAVY RAINFALL AND ISOLD FLASH FLOODING OVER NCNTRL PR. MODELS
SHOW WAVE WEAKENING OVR THE WEEKEND AS IT MOVES ACROSS THE ERN
CARIB BUT EXPECT THERE WILL BE ENOUGH MOISTURE AROUND TO GENERATE
SCT DIURNAL CONVECTION. IN ADDITION...PRES GRADIENT WILL WEAKEN
WHICH SHOULD ALLOW FOR STRONG SEA BREEZE CONVERGENCE OVER INLAND
SECTIONS OF PR AND STEERING WINDS WILL ALSO BE WEAK WHICH SHOULD
FAVOR SLOW STORM MOTION WITH LOCALIZED HEAVY RAINFALL.

&&

.AVIATION...VFR TDY/TONITE XCP MVFR IN SCT AFT SHRA/TSRA SPCLLY
TJMZ/TJBQ WI SOME OBSCD MTNS. SAHARAN DUST HAS LEFT AND MOVD W.
WINDS SFC-FL150 E 15-25 KT BCMG 10-15 KT ON WED.

&&

.MARINE...SEAS 2-4 FT BUT LOCALLY HIGHER NEAR TSTMS. STRONG
THUNDERSTORMS OVER MONA PASSAGE AND CARIB COASTAL WATERS THIS
AFTERNOON.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 81 89 80 / 30 40 40 0
STT 88 81 89 79 / 30 30 30 10

[cycloneye]

INVEST 93L is just east of Belize where our friend BZSTORM is. Let's see what occurs in the next 12-24 hours.

2 PM Tropical Weather Outlook.

A TROUGH OF LOW PRESSURE JUST OFF THE COAST OF BELIZE AND THE
YUCATAN PENINSULA IS PRODUCING A LARGE AREA OF DISORGANIZED SHOWERS
AND THUNDERSTORMS OVER THE NORTHWESTERN CARIBBEAN SEA. THE TROUGH
IS EXPECTED TO MOVE SLOWLY WEST-NORTHWESTWARD AT 5 TO 10 MPH...AND
WILL BEGIN MOVING ACROSS THE YUCATAN PENINSULA TONIGHT...AND ENTER
THE BAY OF CAMPECHE EARLY THURSDAY. SIGNIFICANT DEVELOPMENT IS NOT
EXPECTED WHILE THE TROUGH MOVES OVER LAND...AND THIS SYSTEM HAS A
LOW CHANCE...20 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS. UPPER-LEVEL WINDS SHOULD BE CONDUCIVE FOR THE
FORMATION OF A TROPICAL DEPRESSION OVER THE SOUTHWESTERN GULF OF
MEXICO LATER IN THE WEEK...AND THIS SYSTEM HAS A HIGH CHANCE...70
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
259 PM AST TUE SEP 10 2013

.SYNOPSIS...UPPER LEVEL LOW SOUTHEAST OF THE LOCAL AREA...WILL
CONTINUE TO MOVE WEST AND WILL AFFECT THE LOCAL AREA TOMORROW. A
SLOT OF DRY AIR IS EXPECTED TO MOVE ACROSS THE AREA
THURSDAY. A TROPICAL WAVE WILL APPROACH THE LOCAL REGION FRIDAY.

&&

.DISCUSSION...SCATTERD SHOWERS WERE OBSERVED THIS MORNING ACROSS
THE COASTAL WATERS WITH SOME AFFECTING THE U.S. VIRGIN ISLANDS AND
TE EASTERN HALF OF PUERTO RICO FROM TIME TO TIME. SOME SHOWERS
WITH ISOLATED THUNDERSTORM STARTED TO DEVELOP EARLY THIS
AFTERNOON THE WESTERN INTERIOR AD SOUTHWESTERN SECTIONS OF PUERTO
RICO. THIS ACTIVITY IS PRIMARILY ASSOCIATED WITH STRONG DAYTIME
HEATING...LOCAL EFFECTS AND THE PROXIMITY OF AN UPPER LEVEL LOW.
THIS UPPER LEVEL LOW WHICH WAS LOCATED EARLY THIS AFTERNOON
SOUTHEAST OF PUERTO RICO...WILL MOVE WEST AND IS EXPECTED TO BRING
SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS ACROSS THE LOCAL
AREA TONIGHT. THE TROUGH IS EXPECTED TO MOVE IN A MORE FAVORABLE
AREA TOMORROW...WHICH WILL INCREASE THE CHANCES FOR SHOWERS AND
THUNDERSTORMS. FOR THURSDAY...A SLOT OF DRY AIR WILL MOVE ACROSS
THE REGION THURSDAY.

A TROPICAL WAVE...CURRENTLY AROUND 50 WEST LONGITUDE WILL MOVE
SLOWLY WEST NEXT FEW DAYS. THE LEADING EDGE OF THIS SYSTEM...WILL
AFFECT THE REGION THURSDAY NIGHT INTO FRIDAY. MAIN WEATHER WILL
OCCUR ACROSS THE CORDILLERA CENTRAL OF PUERTO RICO...AND OVER THE
COASTAL WATERS. IN THE LONG TERM...NO SIGNIFICANT WEATHER EVENTS
ARE FORECAST TO AFFECT THE REGION AT THIS TIME.

&&

.AVIATION...VFR CONDITIONS EXPECTED AT ALL TAF SITES EXCEPT MVFR
IN SCATTERED AFTERNOON SHRA/TSRA OVER WESTERN INTERIOR WITH SOME
OBSCURED MOUNTAINS AFFECTING MAINLY TJMZ AT LEAST UNTIL 10/22Z.
WINDS FM SFC UP TO 5 KFT FROM THE EAST 15-20 KT BCMG 10-15 KT ON
WED.

&&

.MARINE...SEAS UP TO 4 FEET AND WINDS UP TO 16 KNOTS ARE EXPECTED.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 81 89 80 89 / 40 40 0 40
STT 81 89 79 89 / 30 30 10 30

[cycloneye]

Good morning. Afternoon showers will form in PR today as a trough moves by. A Tropical Wave will move thru the area on Friday bringing scattered showers.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
518 AM AST WED SEP 11 2013

.SYNOPSIS...
AN UPPER LOW AND ASSOCIATED BROAD TUTT WAS NOW LOCATED JUST SOUTH OF
PUERTO RICO AND EXTENDS NORTHWARDS ACROSS THE NORTHEASTERN CARIBBEAN.
THIS IS INDUCING A WEAK LOW TO MID LEVEL TROUGH WHICH COVERS THE ENTIRE
EASTERN CARIBBEAN. A SURFACE LOW AND ASSOCIATED TROUGH WAS PRESENTLY
MERGING WITH A TROPICAL WAVE NEAR 53 WEST. THIS WAVE WAS ENCOUNTERING
MODERATE NORTHERLY AND SOUTHEASTERLY SHEAR AS IT CONTINUED WESTWARD
TOWARDS THE LESSER ANTILLES.

&&

.DISCUSSION...THE LATEST GFS MODEL GUIDANCE INITIALIZE FAIRLY
WELL AND SHOWED NO MAJOR CHANGES FROM THE PREVIOUS RUN FOR THE
LONG TERM. THE UPPER LOW IS EXPECTED TO CONTINUE RETROGRESSING
WEST OF THE LOCAL AREA AND MOVE OVER HISPANIOLA BY THURSDAY. IN
THE MEANTIME... SHOWERS AND THUNDERSTORMS ARE ONCE AGAIN EXPECTED
TO FIRE UP ACROSS PARTS OF THE ISLANDS DURING THE AFTERNOON. THIS
ACTIVITY WILL BE FOCUSED MAINLY OVER THE INTERIOR AND WESTERN
SECTIONS OF PUERTO RICO. THE AVAILABLE MOISTURE WILL COMBINE WITH
THE DAYTIME HEATING... LOCAL EFFECTS...AND THE FAVORABLE UPPER
LEVEL CONDITIONS...TO PRODUCE AND ENHANCE THE AFTERNOON CONVECTION.
FEW SHOWERS AND POSSIBLY AN ISOLATED THUNDERSTORM MY AFFECT PARTS
OF THE U.S. VIRGIN ISLANDS THIS AFTERNOON BUT MOSTLY SUNNY SKIES
SHOULD PREVAIL. THE AFOREMENTIONED TROPICAL WAVE IS FORECAST TO
ENTER THE EASTERN CARIBBEAN ON FRIDAY AS IT MERGES WITH THE BROAD
SURFACE TROUGH WHICH WILL MOVE ACROSS THE REGION ON SATURDAY. THIS
WILL INCREASE THE CHANCES FOR SHOWERS AND THUNDERSTORM ACTIVITY
ACROSS THE LOCAL ISLANDS AND SURROUNDING WATERS EACH DAY. HOWEVER...
WIDESPREAD RAINFALL IS NOT EXPECTED AT THIS TIME.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED AT ALL TAF SITES EXCEPT
MVFR IN SCATTERED AFTERNOON SHRA/TSRA OVER WESTERN INTERIOR WITH
SOME OBSCURED MOUNTAINS AFFECTING MAINLY TJMZ AT LEAST BETWEEN
11/17Z AND 11/22Z. TJSJ 11/00Z SOUNDING INDICATED AN EASTERLY WIND
FLOW UP TO 20 KNOTS...ALL THE WAY FROM THE SURFACE TO 12K FEET
INCREASING IN SPEED UP TO 45 KNOTS ALOFT.

&&

.MARINE...SEAS ARE EXPECTED TO BE AT 4 FEET OR LESS AND WINDS UP
TO 17 KNOTS TODAY. PLEASE REFER TO THE LATEST COASTAL WATERS FORECAST
ISSUED BY THE NATIONAL WEATHER SERVICE WFO SAN JUAN PR FOR ADDITIONAL
INFORMATION AND UPDATES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 88 78 / 30 10 40 40
STT 88 79 88 80 / 30 20 40 40

[cycloneye]

8 AM Tropical Weather Outlook.

1. A LARGE AREA OF CLOUDINESS AND THUNDERSTORMS OVER THE NORTHWESTERN
CARIBBEAN SEA AND THE YUCATAN PENINSULA IS ASSOCIATED WITH A BROAD
AREA OF LOW PRESSURE. THIS DISTURBANCE SHOULD MOVE OVER LAND TODAY
AND ENTER THE BAY OF CAMPECHE ON THURSDAY WHEN SOME DEVELOPMENT IS
ANTICIPATED. THIS SYSTEM HAS A MEDIUM CHANCE...40 PERCENT...OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. IF THE
SYSTEM REMAINS OVER WATER...UPPER-LEVEL WINDS SHOULD BE CONDUCIVE
FOR ADDITIONAL DEVELOPMENT LATER IN THE WEEK...AND THIS SYSTEM HAS A
HIGH CHANCE...70 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 5 DAYS. LOCALLY HEAVY RAINS AND GUSTY WINDS ARE EXPECTED
OVER BELIZE...GUATEMALA...AND THE YUCATAN PENINSULA DURING THE NEXT
DAY OR TWO.

2. CLOUDINESS AND SHOWERS HAVE INCREASED IN ASSOCIATION WITH A BROAD
AREA OF LOW PRESSURE CENTERED ABOUT 700 MILES EAST OF THE LEEWARD
ISLANDS. THIS LOW IS EXPECTED TO CONTINUE MOVING SLOWLY WESTWARD...
BUT ENVIRONMENTAL CONDITIONS DO NOT APPEAR FAVORABLE FOR ADDITIONAL
DEVELOPMENT. THIS DISTURBANCE HAS A LOW CHANCE...10 PERCENT...OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A LOW
CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 5 DAYS.

[abajan]

It's raining heavily here in the southwest of the island and it looks like the center of the island is getting absolutely pummelled with rain!

[abajan]

Just heard the first clap of thunder. More to come for sure.

[Gustywind]

Just heard the first clap of thunder. More to come for sure.

Oh boy be aware Abajan! Looks like things are pretty hot in your island. Keep us informed as possible.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
303 PM AST WED SEP 11 2013

.SYNOPSIS...UPPER LEVEL LOW SOUTHWEST OF THE LOCAL AREA...WILL CONTINUE
TO MOVE WEST AND WILL MOVE AWAY FROM THE LOCAL AREA TONIGHT. A SLOT OF
DRY AIR IS EXPECTED TO MOVE ACROSS THE AREA TONIGHT AND EARLY
THURSDAY. THE LEADING EDGE OF A TROPICAL WAVE WILL AFFECT THE
REGION THURSDAY AFTERNOON.

&&

.DISCUSSION...AN UPPER LEVEL TROUGH WAS PASSING SOUTH OF THE LOCAL
AREA TODAY. EARLY THIS AFTERNOON...SHOWERS DEVELOPED ACROSS THE
CORDILLERA CENTRAL OF PUERTO RICO AND OVER THE SOUTHWEST SECTION
OF PUERTO RICO. RAINFALL AMOUNTS WERE LESS THAN ONE INCH OF
RAIN...AS THESE SHOWERS WERE MOVING QUICKLY. FOR TONIGHT...A SLOT
OF DRIER AIR WILL MOVE ACROSS THE REGION...LIMITING THE SHOWER
ACTIVITY ACROSS THE REGION.

A TROPICAL WAVE AND ASSOCIATED AREA OF LOW PRESSURE WAS LOCATED
AROUND 52 DEGREES LONGITUDE EARLY THIS AFTERNOON. THIS WAVE WILL
CONTINUE TO MOVE SLOWLY WEST-NORTHWEST NEXT COUPLE OF DAYS. THE
LEADING EDGE OF THIS SYSTEM IS EXPECTED TO AFFECT THE LOCAL REGION
TOMORROW AFTERNOON. THE MOISTURE ASSOCIATED WITH THIS
SYSTEM...COMBINED WITH DAYTIME HEATING AND LOCAL EFFECTS PROMISE
TO BRING AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY ACROSS
THE AREA.

AFTER THE PASSAGE OF THIS SYSTEM...NO SIGNIFICANT WEATHER EVENTS
ARE FORECAST TO AFFECT THE REGION. THE WINDS ARE EXPECTED TO SHIFT
TO A MORE SOUTHERLY COMPONENT SUNDAY MORNING....WHICH COULD
INCREASE SOMEWHAT THE LOCAL TEMPERATURES MAINLY ALONG THE NORTHERN
HALF OF PUERTO RICO.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED AT ALL TAF SITES. EAST
WINDS FM SFC UP TO 5 KFT AT 5-15 KT BCMG MORE NORTHEAST AFTER
12/00Z. SOME SHOWERS ARE POSSIBLE AFTER 12/06Z NEAR TIST...TNCM AND
TKPK.


&&

.MARINE...SEAS UP TO 4 FEET AND SEAS UP T 17 KNOTS ARE EXPECTED
OVER THE COASTAL WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 88 79 88 / 10 40 40 40
STT 79 88 80 88 / 20 40 40 40

[Macrocane]

Heavy rains have been affecting El Salvador since this morning, our met office is forecasting a "temporal" (situation with at least 24 h of persistent rains that can reach 100 mm). Floods reports are already coming out. This is the lateste HPC discussion:

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
213 PM EDT WED SEP 11 2013

DISCUSSION FROM SEPTEMBER 11/00UTC: SUBTROPICAL RIDGE REMAINS THE
DOMINANT FEATURE ACROSS CENTRAL-NORTHERN MEXICO TO THE SOUTHWEST
USA. THE RIDGE ALOFT...AS IT HOLDS...IS VENTING DIURNAL CONVECTION
ALONG THE SIERRA MADRE OCCIDENTAL...WHERE WE EXPECT RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. HIGHER AMOUNTS ARE
EXPECTED ON THE CENTRAL STATES OF MEXICO TO THE SIERRA MADRE DEL
SUR...WITH ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 25-50MM EARLY
IN THE CYCLE. THROUGH 36-72 HRS DAILY MAXIMA DECREASE TO 20-40MM.

THE UPPER LEVEL RIDGE...AS IT HOLDS...IS TO STEER A SHORT WAVE
TROUGH ACROSS TEXAS TO THE NORTHERN GULF/NORTHEAST MEXICO. AS IT
ENTERS THE GULF...IT WILL THEN MERGE WITH A SHORT WAVE TROUGH TO
THE SOUTH AS THE LATTER MEANDERS OFF THE GULF COAST OF MEXICO.
THESE ARE THEN TO COMBINE INTO A SHORT WAVE TROUGH THAT CENTERS ON
A CLOSED LOW OVER SOUTHERN TEXAS/NORTHERN TAMAULIPAS MEXICO. THE
SHORT WAVE TROUGH ALOFT SUSTAINS AN UPPER DIVERGENT PATTERN ACROSS
THE CENTRAL-SOUTHERN GULF OF MEXICO TO THE YUCATAN PENINSULA. THIS
IS ENHANCING CONVECTIVE DEVELOPMENT IN ASSOCIATION WITH A MID
LEVEL TROUGH RETROGRESSING ACROSS THE YUCATAN. THE MID LEVEL
TROUGH CONTINUES TO INTERACT WITH THE EASTERN PACIFIC ITCZ...
SUSTAINING A LOW LEVEL CIRCULATION OVER THE GULF OF TEHUANTEPEC.
AS THE MID LEVEL TROUGH ENTERS THE SOUTHERN GULF GLOBAL MODEL
GUIDANCE SHOW A NEW LOW FORMING OVER THE CAMPECHE SOUND. NOTE THAT
THE NHC IS EVALUATING THIS AREA FOR POSSIBILITY OF TROPICAL
CYCLONE FORMATION. MEANWHILE...AS THEY INTERACT...THESE ARE TO
ANCHOR THE ITCZ ALONG ITS CLIMATOLOGICAL POSITION OVER SOUTHERN
MEXICO-NORTHERN CENTRAL AMERICA. ACROSS THE SOUTHERN STATES OF
MEXICO TO GUATEMALA THIS IS TO FAVOR RAINFALL AMOUNTS OF
25-50MM/DAY AND MAXIMA OF 75-125MM. THROUGH 72 HRS THIS IS
EXPECTED TO INCREASE TO 50-75MM/DAY AND MAXIMA OF 150-250MM. IF A
TROPICAL CYCLONE DEVELOPS IN THIS AREA...STRONG TOPOGRAPHICAL
FORCING IS LIKELY TO SUSTAIN MAXIMA IN EXCESS OF 300MM. ACTIVITY
IS TO GRADUALLY BUILD NORTH ALONG THE COAST OF VERACRUZ TO
TAMAULIPAS... WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY
AND MAXIMA OF 30-60MM/DAY. THROUGH 96 HRS MAXIMA INCREASES TO
40-80MM. ACROSS EL SALVADOR-HONDURAS AND NORTHWEST NICARAGUA
INITIALLY EXPECTING ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF
40-80MM/DAY. AS CONVECTION TO THE WEST INTENSIFIES...THIS WILL
GRADUALLY DECREASE TO 10-15MM/DAY AND MAXIMA OF 20-35MM BY 72-96
HRS.

EAST OF THIS AXIS...OVER THE WESTERN ATLANTIC...A CLOSED LOW NEAR
30N 80W EXTENDS A SHORT WAVE TROUGH ACROSS THE FLORIDA PENINSULA
TO NORTHWEST CUBA. LOW IS TO SLOWLY LIFT NORTH INTO THE SOUTHEAST
USA...WITH BASE OF THE TROUGH PULLING AWAY. BY 60-72 HRS THIS IS
TO THEN YIELD TO AN AMPLIFYING TROUGH OVER THE EASTERN USA/WESTERN
ATLANTIC. MEANWHILE...THE TROUGH ALOFT IS TO ENHANCE CONVECTION
ACROSS WESTERN PORTIONS OF CUBA...WHERE IT IS TO FAVOR RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM THROUGH 36 HRS. OTHER
ACTIVITY IS EXPECTED ACROSS THE NORTHWEST BAHAMAS EARLY IN THE
CYCLE...WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM.

RETROGRESSING TUTT LOW OVER THE CARIBBEAN NOW CENTERS NEAR 17N
70W. THE LOW EXTENDS A SHORT WAVE TROUGH SOUTH TO NORTHERN
VENEZUELA. THIS FAVORS A WEAK UPPER DIVERGENT PATTERN ACROSS THE
NORTHEAST CARIBBEAN ISLANDS. THE UPPER TROUGH MEANDERS ACROSS 75W
BY 48 HRS...TO THEN STALL ALONG 77W/78W LATER IN THE CYCLE. ON ITS
WAKE...A SHORT WAVE RIDGE IS TO BRIEFLY ESTABLISH ACROSS THE
EASTERN CARIBBEAN ISLANDS. THE RETROGRESSING UPPER TROUGH...
MEANWHILE...IS TO VENT ISOLATED TO SCATTERED CONVECTION ACROSS
PUERTO RICO TO HISPANIOLA...WHERE IT IS TO FAVOR RAINFALL AMOUNTS
OF 05-10MM/DAY AND MAXIMA OF 15MM AT 12-24 HRS. AS IT NEARS
JAMAICA LATER ON DAY 02 IT IS TO SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. MOST ACTIVE CONVECTION IS
EXPECTED ALONG THE BASE OF THE UPPER TROUGH AS IT INTERACTS WITH
THE NEAR EQUATORIAL TROUGH OVER NORTHERN COLOMBIA/VENEZUELA.
ACROSS CENTRAL VENEZUELA-ABC ISLES IT WILL SUSTAIN RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-30MM. THROUGH 48 HRS
MAXIMA DECREASE TO 15-20MM. ACROSS NORTHWEST VENEZUELA TO NORTHERN
COLOMBIA EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-40MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL 24 36 48 60 72 84 96 TYPE
51W 54W 58W 61W 65W 68W 71W 74W TW
63W 66W 70W 73W 76W 79W 80W 84W EW
69W 73W 76W 79W 81W 84W 87W 90W TW
88W 91W 93W 96W DISSIPATES TUTT INDUCED

TROPICAL WAVE INITIALIZED ALONG 51W HAS EMBEDDED LOW CENTERED NEAR
17 NORTH. THE NHC IS MONITORING THIS CLUSTER FOR TROPICAL CYCLONE
DEVELOPMENT. WAVE IS IN PHASE WITH A DEEP TUTT OVER OPEN ATLANTIC,
EXTENDING FROM THE EQUATOR WITH A CLOSED LOW CENTERED NEAR 24N
44W. POSITIVE INTERACTION WITH UPPER TROUGH TO THE NORTH FAVORS
ORGANIZED DEEP CONVECTION ALONG THIS FEATURE. OVER THE LESSER
ANTILLES TO PUERTO RICO THE WAVE IS EXPECTED TO PRODUCE RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM BY 36-48 HRS. SOUTH
OVER THE GUIANAS...EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15-20MM. ACROSS HISPANIOLA EXPECTING ACCUMULATION OF
05-10MM/DAY AND MAXIMA OF 15-20MM.

EASTERLY WAVE INITIALIZED ALONG 63W HAS BEST SIGNATURE NORTH OF
14N. THE PERTURBATION IS TO ENHANCE CONVECTION OVER THE GREATER
ANTILLES BY THROUGH MID CYCLE. THROUGH 54 TO 60 HOURS OVER
HISPANIOLA AND THE SOUTHEAST BAHAMAS/TURKS AND CAICOS...EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM. THROUGH 72
HRS... HOWEVER...UPPER CONVERGENT PATTERN OVER THE CARIBBEAN IS TO
DECREASE CONVECTION ALONG THE WAVE AXIS. OVER CUBA THE WAVE
ENHANCES DIURNAL CONVECTION TO TRIGGER RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15MM.

LOW AMPLITUDE TROPICAL WAVE ALONG 70W IS MOVING TO CONVERGENT SIDE
OF THE EASTERN CARIBBEAN TUTT. STRONGEST LOW LEVEL MOISTURE
CONVERGENCE OCCURS SOUTH OF THE AXIS ALONG THE ITCZ. OVER WESTERN
VENEZUELA AND COLOMBIA...THIS IS TO RESULT IN RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-45MM EARLY IN THE CYCLE. THROUGH 48
TO 60 HOURS...MOST ACTIVE CONVECTION EXPECTED OVER PANAMA/COSTA
RICA...WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM.
WAVE IS ABSORBED BY A BROAD AREA OF LOW PRESSURE OVER THE SOUTHERN
GULF LATER IN THE CYCLE.

A MID-LEVEL TROUGH INDUCED PERTURBATION ALONG 88W ENHANCES
ORGANIZED CONVECTION OVER THE SOUTHERN STATES OF MEXICO THROUGH 36
TO 48 HOURS. THIS WAVE...IN INTERACTION WITH A NASCENT LOW OVER
THE SOUTHERN GULF...IS TO ENHANCE MOISTURE CONVERGENCE ACROSS THE
YUCATAN-NORTHERN CENTRAL AMERICA TO SOUTHERN MEXICO. THROUGH THE
PERIOD...THIS IS TO FAVOR RAINFALL AMOUNTS OF 25-50MM/DAY AND
MAXIMA OF 75-125MM. THROUGH 48-72 HRS MAXIMA INCREASES TO
150-250MM AS THE PERTURBATION MERGES WITH CYCLONIC CIRCULATION.

MILLER...CINWS (CAYMAN ISLANDS)
ROBINSON...MSJ (JAMAICA)
DAVISON...WPC (USA)

[Macrocane]

Saved IR image:



Pictures of today's floods (upper picture is from the central coast and the lower is from eastern coast):

[msbee]

Hope everyone will be safe Marocane

[cycloneye]

8 PM Tropical Weather Outlook.

A LIMITED AMOUNT OF DISORGANIZED CLOUDINESS AND SHOWERS ARE
OCCURRING IN ASSOCIATION WITH A BROAD AREA OF LOW PRESSURE CENTERED
ABOUT 600 MILES EAST OF THE LEEWARD ISLANDS. THIS LOW IS EXPECTED
TO CONTINUE MOVING SLOWLY WESTWARD...BUT ENVIRONMENTAL CONDITIONS
APPEAR HOSTILE FOR DEVELOPMENT. THIS DISTURBANCE HAS A LOW
CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS...AND A LOW CHANCE...10 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 5 DAYS.

[abajan]

@Macrocane
With Invest 90E on one side and Invest 93L on the other and both systems moving quite slowly, it's no wonder that El Salvador is getting so much flooding. Stay as safe as you can.

[abajan]

The close proximity of the LOW mentioned in the last TWO is definitely affecting the pressure readings and wind direction here:



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(Our winds are normally anywhere from the ENE to the ESE.)