It has been a wet start of 2005 for San Juan and NE carib

[cycloneye]

puerto rico and u. s. virgin islands forecast discussion
national weather service san juan pr
313 pm ast tue jan 18 2005

. synopsis ... at upper levels ... a long wave trough has moved into
place north the area. a 125 knot jet will pass north of the area at
about 27 degrees north ... tonight through thursday and puerto rico
will be in the right rear quadrant of this jet thursday night
through friday. a short wave trough will pass through on friday
night followed by decreasing west winds during the weekend. flow
will remain west and generally above 50 knots at 250 mb for the rest
of next week.

at mid levels ... the long wave trough has set up north of the area
and a front is now moving slowly into hispaniola. it will continue
to move forward but may have to reorganize before moving through our
area. the 500 mb trough will move through on saturday ... but flow
will remain generally west or west southwest thereafter.

at lower levels.... a cold front extends from 40 north 52 west to 29
north 60 west across haiti to 20 north 72 west. a band of convection
lays parallel to the front over the mona passage and does not appear
to be moving at this time. an inverted trough can also be found over
the windward islands with convection just to the east of the crest.
these moisture areas are forecast to join over the local area
tonight through thursday morning. presently the low level moisture
maximum will appear southeast of puerto rico and over saint croix
thursday morning and return on saturday. moisture will remain just
northwest of the area sunday and monday and then a second impulse
will drive it through monday night. and yes ... it is forecast to come
back again on the following wednesday night.

&&

. discussion ... an interesting weather pattern has emerged in the
satellite imagery of the day. a frontal band is clearly visible
southwest to northeast across haiti with a wide mass of cloud cover
amassed a short distance behind it and extending almost to the east
coast of the united states. this is the scenario mentioned in a
previous afd and it looks like the gfs gets a gold star for an
accurate rh forecast. thus we will continue to follow the gfs as we
track the cold front boundary into the area. the satellite picture
with the surface gfs 150 flow overlaid suggests that the col
region of the front is near 25 north 62 west ... and so it is not
surprising that the front ... or more accurately the convergence
band ... is only moving toward the area at 5 knots. further
complicating matters is the band of convergence over the mona
channel which has been sending a few showers across the northwest
tip of puerto rico and the band of moisture moving northwest on the
atlantic side of the windward islands. models are having a difficult
time resolving these complicated moisture bands and so it is placing
high relative humidity amounts over the entire area ... but believe
that using these relative humidity forecasts would cause us to over
forecast rain chances and amounts and therefore have been
conservative with the daytime pops forecasts ... especially over
northern puerto rico and the virgin islands. stronger flow over the
central mountains should increase the chances of showers tomorrow
over a slight trend to this effect today. overnight showers should
be able to move in over the islands northeastern half for decent
coverage of the area. subsequent days become tricky as the forecast
is entirely dependent on the exact position of the front wednesday
through tuesday. it looks like a fairly moist airmass will be in
place ... but upper level divergence is depicted as weak despite the
fact that we are under the right rear quadrant of a relatively
strong jet for this latitude. therefore although the forecast is for
wetter weather than usual through saturday night ... there may be
times when winds are unfavorable for rain for one part of puerto
rico or the other ... as when the prevailing surface winds turn
southeasterly on saturday night readying for the return of the only
shortly passed frontal boundary ... leaving san juan in a relative
shadow area. this should result in a general increase in the shower
activity in the virgin islands and they will receive rain ... though
amounts are not likely to be large or lead to flooding. the front
washes back and forth but moisture is spottier after sunday.

winds should become quite a bit lighter after thursday when low
level winds become light and variable ... but will pick up with a
southerly component beginning saturday and continuing through
sunday ... until monday when low level flow becomes westerly. even
surface winds may pick up an uncharacteristic westerly component
beginning monday in advance of the third return of the boundary
layer moisture. by wednesday of next week weak trade wind flow will
return to the local islands and yet again another pass by high
relative humidities.

the monthly total rainfall for the airport at san juan is already
above normal for the the month as a whole and this trading back and
forth of boundary passages can only help us to an exceptionally wet
january.

&&

. marine ... seas are declining again for a short while ... but will
return on wednesday afternoon with a period of 10 seconds from the
east northeast. then an additional swell ... generated by flow around
a strong high over virginia this evening ... is forecast to appear
rather suddenly late thursday afternoon with a 9 second period from
due north. this will make for confused seas of nearly 10 feet in the
outer waters of the atlantic ... and some swell should make it onto
north coastal beaches by tomorrow night. seas will peak in height on
thursday afternoon and evening and then very slowly subside. on
saturday a much longer period swell is forecast to enter the area
from the northeast ... having been generated by the strong gradient
between a low off the west african coast and the high in the
northeast atlantic. 5 foot swell with a period of 14 to 15 seconds
will arrive friday night and increase to 6 feet at 13 seconds on
saturday. although the period will decrease ... this swell will still
be significant on sunday and monday. tuesday will mark another event
from another strong low that tracks over the atlantic offshore from
the eastern seaboard.

in the caribbean ... seas generally remain around 3 to 4 feet until
saturday. almost all the energy in these seas is arriving from the
east northeast. next weekend we will see relatively quiet seas on
the caribbean side.

will allow the small craft advisory for the anegada passage to lapse
in the face of decreasing seas in the atlantic ... but small craft
should exercise caution there.

No doubt rain will arrive from tonight to the islands as a weak trough combines with the frontal boundary and that will keep the wet totals over the normal amount for january.Barbara I thinik that the boat for thursday will have to be left on port as confused seas will occur as waves from the NE and NW will combine and at about 10 feet.

[Rainband]

wasn't it like this last year in PR Hope this isn't a sign of the Hurricane Season!!!

[cycloneye]

wasn't it like this last year in PR Hope this isn't a sign of the Hurricane Season!!!

Last year San Juan had 63.40 inches of rain over 9 inches above normal for a year long rainfalling totals at the San Juan International Airport.And coinsidence Jeanne made landfall here as a 70 mph storm.I am not inplying that this year it will be another active caribbean but 2005 has started like 2004 in a wet mode.

[Rainband]

I know. I guess time will tell

[cycloneye]

puerto rico and u. s. virgin islands forecast discussion
national weather service san juan pr
545 am ast wed jan 19 2005

. discussion ... a sharp surface trough extended from southeast of
barbados north northwest to near 22. 5 degrees north 60. 0 degrees
west ... and was nearly stationary early this morning ... although
beginning to shift southeast. an old frontal boundary extending from
eastern hispaniola northeast across the west central atlantic was
moving slowly southeast this morning and will get a secondary push
and be forced more quickly southeast today and tonight into the
local atlantic waters by strong high pressure building off the
southeastern u. s. coast. this boundary is then expected to merge
with the surface trough thursday through friday across the east
caribbean. it is then forecast to drift back toward the northwest
and across the local area late saturday through sunday.

expect variably to mostly cloudy skies to be the rule across the fa
today and tonight and probably through at least the first part of
thursday ... along with scattered to mostly numerous showers. also...
as mentioned in earlier discussions ... dynamics will be much better
during the next couple of days and this should enhance showers and
lead to some thunderstorm development as well. some limited
drying ... with the emphasis on some and limited ... is possible later
thursday through friday/friday night ... although gfs seems to
indicate the likelihood of small vortices developing along the old
boundary ... so its location will be crucial to cloud and
precipitation forecast across fa. then ... old boundary still appears
destined to lift back to the northwest and at least clip local
islands later saturday through sunday ... for yet more cloudiness and
precipitation. so ... still looks like a very unsettled spell of
weather ... especially for mid january.

&&

. marine ... long period ... north northwest swells will begin to affect
the local atlantic coastal waters and the caribbean passages this
morning ... build significantly this afternoon and tonight ... and then
continue through at least thursday. these 5 to 7 foot swells will
produce breaking waves of 10 to 15 feet or higher along the local
reefs ... beaches and shoals ... resulting in hazardous surf conditions.
we issued a high surf advisory for the northwest through northeast
coasts of all of the local islands with this forecast package. a
small craft advisory remains in effect for the atlantic off shore
waters and will likely be required for the atlantic near shore
waters ... all caribbean passages and the outer caribbean waters for
tonight.

&&

hydrology ... synoptic set - up should continue to allow for scattered
to mostly numerous showers to move across the local islands today
and tonight and through at least the first part of thursday.
although no widespread flooding is expected ... these showers will
continue to result in increasingly moist ground conditions ... with
runoff increasing into local streams and rivers. urban and small
stream flooding is likely to occur later today and tonight in some
areas. also ... already have a couple of "larger" rivers at above
normal levels and with additional rainfall ... and building north
northwest swells not allowing for normal drainage to sea ... could
eventually have one or two river flood problems as well.

http://www.srh.noaa.gov/radar/loop/DS.p ... tjua.shtml

Rain is here this morning at San Juan with cloudy and scattered showers moving from the Atlantic.Seas are way high between 10-15 feet.

[cycloneye]

fxca62 tjsj 191940
afdsju

puerto rico and u. s. virgin islands forecast discussion
national weather service san juan pr
340 pm ast wed jan 19 2005

. synopsis ... at upper levels ... long wave troughing continues north of
the area. a jetstreak of 125 knots will pass north of san juan at
about 27 north today through thursday. the center of this jet will
sag to about 20 degrees north by friday placing us in the right rear
quadrant of the jet. a short wave trough passes through saturday
night. on sunday westerly flow weakens below 50 knots until tuesday
when another jet streak passes north of the area.

at mid levels ... a trough to our west will strengthen some and pass
over the islands saturday evening. gradients will weaken
considerably sunday and monday and then another shortwave will
approach tuesday and wednesday and then the following friday. all
troughs at this level are much weaker at our low latitudes than near
40 north.

at lower levels ... the old frontal boundary has left a considerable
amount of moisture in place just north of hispaniola but has moved
on to join the low level trough that was near the windward islands.
this has left us with almost northerly low level flow. the moisture
band left over is becoming oriented in a more east - west direction
and is sagging into puerto rico and the u. s. virgin islands. much of
that moisture is streaming across the area bringing occasional
showers to the north coast and scattered showers to the south coast.
the frontal boundary will move south of the area tomorrow and drier
air will fill in. on saturday ridging will build across the atlantic
between 20 and 25 north and a modest high pressure will fill the mid
atlantic. on sunday a strong low pressure will move off the eastern
coast of the united states and push the ridge ... extending from the
high in the mid atlantic ... over the local area. a weak trough will
pass through the area on tuesday then high pressure will ridge east
from florida and east northeast trade wind flow will return.

&&

. discussion ... the 12z sounding this morning showed the dramatic
difference between the nearly saturated low layers and the almost
completely dry mid and upper layers. from satellite pictures it
appears that moisture is even deeper and greater just to our
north ... out of which current surface flow is coming. models are
showing the best moisture to be around 00z thursday ... tonight...
tapering off slowly overnight ... perhaps as the moisture band
associated with a second impulse from the northwest moves across the
area. then the moist layer become slightly drier ... and the height of
the 50 percent relative humidity line drops from about 630 mb at 21z
today to 720 mb at 00z friday and according to the gfs continues
down to 850 mb by saturday morning. therefore will keep pops
considerably lower from mid afternoon on thursday through sunday.
after thursday ... most of the rain on the northeast coast will come
in the early morning hours out of flow that persists from the
northeast ... until the first of the week and then surface flow
gradually becomes southeast.

the gfs does not seem to hold the old moisture band together once it
passes ... but a new one does form northwest of us toward the
beginning of the week and is forecast to pass through on tuesday or
wednesday. showers should begin to increase late tuesday into
wednesday morning ... but the latest run sends this band back to the
northwest without it having traversed the area.

the upshot of all this is that wet weather begins this afternoon and
continues through noon tomorrow. drier weather with scattered
showers most prevalent in the northeast part of puerto rico at night
will commence thursday afternoon and last till monday. then a little
more moisture should return. have lowered pops during this drier
period for the most part although some pops were okay. drier weather
this weekend unfortunately does not mean the total cessation of rain
here so would expect little drying of soils.

&&

. hydrology ... with additional rain some rivers on the north central
coast have risen to within 6 or 7 feet of flood stage ... but with
current rates of rainfall they do not show signs of rising further.
will need to monitor this situation closely but will leave to the
following forecaster the decision of whether to issue a flash flood
watch for smaller streams that will likely become swollen with
rapidly moving waters tonight. the threat of mudslides will increase
through tonight with the heavier rains ... since ground is completely
saturated.

&&

. marine ... have extended the high surf advisory through at least 6 am
thursday. local observations show that rough seas have arrived and
are not expected to subside until later tomorrow. even then ... seas
will remain fairly high so the hsa may continue even through
tomorrow. seas subside slowly through the rest of the week until a
new set of northwest swell arrives here the following monday.
heights thursday of next week are expected to be similar to that
being experienced today and tomorrow. seas in the caribbean will be
much quieter ... generally 4 to 5 feet or less. passages from the
atlantic excepted.

http://www.srh.noaa.gov/radar/loop/DS.p ... tjua.shtml

Looks like the weekend will be drier hopefully that comes thru.

[cycloneye]

puerto rico and u. s. virgin islands forecast discussion
national weather service san juan pr
600 am ast thu jan 20 2005

. discussion ... running very late due to weather ... so will try to be
brief. generally had 2 to 5 inches of rainfall across local islands
wednesday evening through early this morning ... which caused some
localized flash flooding and still have rio grande de manati and rio
cibuco flooded at this time ... with a flood warning in effect until
1200 pm. large north northwest swells are impeding the drainage of
these two rivers seaward.

culprit for active weather was old frontal boundary and associated
low level convergence interacting with local islands and being
enhanced by mid to upper level dynamics.

early this morning ... old frontal boundary extending from the
caribbean waters northeast across the u. s. virgin islands and then
continuing northeast across the atlantic early this morning ... will
continue moving slowly south southeast through tonight. the boundary
will become nearly stationary across the lesser antilles friday and
friday night ... then drift back to the west northwest saturday
through sunday. expect a continuation of cloudiness ... at least
numerous showers and isolated thunderstorms through today and into
tonight. "slight" drying for friday and friday night and then
cloudiness and showers should return by later saturday through at
least sunday.

have continued ffa for all of local islands except prz007 - 010 - 011
through 1200 pm ... due to antecedent near to or saturated grounds and
above normal river levels and potential for additional rainfall this
morning.

&&

. marine ... large north northwest swells will continue to affect the
local atlantic waters and the caribbean passages through tonight...
then subside slowly friday and friday night. we have extended the
high surf advisory for all northwest through northeast coasts of all
of the local islands through at least 1100 pm tonight. a small craft
advisory is in effect for all of the atlantic waters ... the caribbean
passages and the near shore waters of western puerto rico and have a
precautionary statement for the remaining waters.


There haved been flash flood warnings that were issued last night and this morning some areas continue with that.There is a flash flood watch for north,central and eastern Puerto Rico.The good news is that the bad weather will be out by tonight and the weekend although not perfect willbe with less rain.

[cycloneye]

puerto rico and u. s. virgin islands forecast discussion
national weather service san juan pr
425 pm ast thu jan 20 2005

. discussion...

lingering moisture from the frontal boundary continues across the
region. the suite of model guidance more or less has a consensus of
a general drying trend over the next 24 hours. at the same time the
sat imagery indicates some drier air approaching from the
west ... being advected in by the low level winds. also the stability
indices from the 12z sounding indicated a slightly drier and more
stable air mass. but with these lingering moisture boundaries the
guidance sometimes has a hard time depicting the low level moisture
as it is sometimes in such a thin low level layer. but for now will
go with the guidance consensus ... i. e. lingering low level moisture
continuing through at least friday ... but in general a slow drying
trend should be expected. sat imagery and guidance indicate that
best chance of heavier showers should be southeast of puerto rico
and in vicinity of st croix tonight and tomorrow.

Things are improving here after a 24 hour period of rains.

[cycloneye]

...THE SAN JUAN/P.R. CLIMATE SUMMARY FOR JANUARY 20 2005...
VALID TODAY AS OF 0500 PM LOCAL TIME.

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1956 TO 2005

WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
..................................................................
TEMPERATURE (F)
TODAY
MAXIMUM 78 215 PM 89 1966 82 -4 84
MINIMUM 69 935 AM 64 2000 71 -2 73
AVERAGE 74 76 -2 79

PRECIPITATION (IN)
TODAY 0.70 2.63 1977 0.09 0.61 0.03
MONTH TO DATE 5.08 2.03 3.05 1.92
SINCE DEC 1 9.73 6.60 3.13 7.17
SINCE JAN 1 5.08 2.03 3.05 1.92

The latest rain event increased the january rainfall to over 3 inches over the normal amount so far in the month.It looks like a wet 2005 similar to 2004 which was a very wet year is instore for Puerto Rico unless the pattern to a dry spell arrives.

[cycloneye]

puerto rico and u. s. virgin islands forecast discussion
national weather service san juan pr
630 am ast fri jan 21 2005

. discussion...
significant clearing of mid level moisture has occurred past 12
hours as deep layered westerly flow has worked downward below 700
hpa bringing drier air. this has left very shallow moisture embedded
in the llvl flow advecting into the area in a nne flow that should
become even more shallow today. this nne to ne flow normal to the
cordillera central of p. r. should cause damming and convergence for
shallow stratoform type precip today ... initially very spotty this
morning but should become more scattered later in the morning and
into the afternoon. diurnal heating and milder winds may allow for a
few convective cells to develop across the interior and sw of the
island ... while the more stratoform precip will prevail across the
virgin islands and local waters. cooler drier air is indicated
across the local area this morning with dewpoints in the middle and
upper 60s along the coasts. also ... with clearing skies overnight...
mild winds ... and high soil moisture content from persistent rains...
stlt imagery suggests widespread fog across the interior of p. r. and
will likely occur again tonight and saturday morning.

surface high just ne of the se bahamas will be forced ese into the
central atlc by late saturday and allow a very brief return flow
across the local area out ahead of next cold front expected across
the local area early tuesday. this return se flow on sunday is
forecast to bring the frontal remnants in the carib now along 15 - 16
north back across the local islands for good llvl moisture and
instability and should lead to scattered showers. next approaching
frontal system will then spank this returning boundary back
southeastward across the local area monday followed by a fropa
monday evening through tuesday. a progressive upper pattern is then
forecast for the eastern u. s. and western atlantic for the next week
and should allow additional frontal boundary to sweep across the
region and maintain moderate rain chances. thus the beginning of the
dry season is not yet in sight.

&&

. marine...
nly swells continue this morning. however ... my evening observation
in san juan suggested swells were only 4 - 6 ... maybe occasionally 7 ft
at that time ... with wwiii indicating a decreasing trend.
additionally ... the french buoy 41100 may have already peaked
overnight although wwiii is forecasting a peak there this evening
from nly swell. given this and the fact that navy swaps keep the
local marine area at 8 ft or below next 24 hours ... i have lowered
marine forecast for local atlantic ... subsiding to 8 feet today then
7 - 8 ft next 24 - 36 hours as strong pulse of ne swell from canary
islands low moves in saturday. high surf advisory is likely
marginal this morning and will allow it to remain in effect until 10
am until visual obs can aid us. with no ship obs reporting seas
recently ... and zero buoys in the local waters ... it is very often
difficult to make an accurate marine forecast here ... and thus we are
typically bound to guidance ... good ... bad ... or ugly. sorry!


Another front will come down by tuesday bringing more rain to Puerto Rico prolonging the wet january we haved seen but at least the weekend will not be to bad.

[msbee]

and at least we will not be having a major snow storm like the one they are expecting in the Notheast USA this weekend.

[cycloneye]

and at least we will not be having a major snow storm like the one they are expecting in the Notheast USA this weekend.

You are right on that.

[cycloneye]

fxca62 tjsj 242046
afdsju

puerto rico and u. s. virgin islands forecast discussion
national weather service san juan pr
400 pm ast mon jan 24 2005

. discussion.. broad mid to upper level high pressure over the
caribbean and tropical atlantic waters extends north across the
local region. this is producing a west southwest upper wind flow
over the region which has continued to transport considerable
amounts of mid to upper level clouds over the local area. upper jet
segment just north of the local region will continue east and move
across the local region overnight through tuesday morning. in the
low levels ... a strong cold front across the west atlantic extending
southwest across eastern cuba and the windward passage will continue
to rapidly move east across the atlantic ... as surface high pressure
across the gulf states builds into the atlantic behind the cold
front. the proximity of the upper jet axis forecast to move across
the local region on tuesday along with northerly wind flow and
increasing low level moisture with the approaching cold
front ... will make way to unstable and wetter weather conditions
across the local region ... especially on tuesday and wednesday.
latest gfs guidance has the frontal system stalling pretty much over
or just south of the local area on tuesday and by late wednesday and
thursday a more easterly wind flow will return maintaining the low
level moisture over the area. eta forecast soundings also depict an
increase in low level moisture and precipitable water over the next
couple of days.

&&

. hydrology....
with the expected moderate northerly wind flow on tuesday ... along
with saturated terrains ... and the potential for moderate to heavy
rainfall ... weather conditions should be watched closely over the
next few days ... as rivers along the north coasts will have
difficulty in draining into the atlantic. a coastal flood
watch ... high surf advisory has been issued for north for
the north facing coast.

&&

. marine...
marine conditions are forecast to deteriorate significantly tuesday
through wednesday with seas reaching between 8 - 11 feet by tuesday
afternoon.


Here comes more rain to cement one of the wettest januarys on record as the cold front the same one that tumbled the temps in Florida yesterday and today will pass thru the NE caribbean.