Thursday, May 25, 2023

..TROPICAL WEATHER OUTLOOK FOR MAY 25, 2023..

 


STILL MONITORING A FRONTAL BOUNDARY AND MULTIPLE LOWS THAT ARE PRODUCING STRONG STORMS OVER FLORIDA THE PAST FEW DAYS.  THIS LOW WILL EVENTUALLY MOVE INTO THE ATLANTIC AND TRACK TOWARD THE CAROLINA COAST AS A WEAK LOW SATURDAY AND SUNDAY.  

THIS LOW COULD BE ACCOMPANIED BY GUSTY WINDS, AND HEAVY RAINS AS IT MOVES INLAND BRIEFY BEFORE TRACKING OFFSHORE CAPE HATTERAS NORTH CAROLINA.

RAINS AND STORMS ARE STILL LIKELY OVER A PORTION OF FLORIDA BUT THERE IS NO MARGINAL RISK PER SPC.  EXPECT A CHANCE FOR RAIN AND STORMS THIS AFTERNOON AND EVENING.  

REFER TO NHC BELOW FOR TROPICAL OUTLOOK FOR THE REST OF THE ATLANTIC, CARIBBEAN SEA AND THE GULF OF MEXICO.

RTW

NATIONAL HURRICANE CENTER TROPICAL OUTLOOK


ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Thu May 25 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. Southwestern Atlantic:
A non-tropical area of low pressure is expected to form along a 
frontal boundary offshore of the southeastern United States coast 
within the next day or two. The system appears unlikely to become  
a subtropical or tropical cyclone since it is forecast to remain 
frontal while moving generally northward and inland over the 
Carolinas this weekend.

Regardless, the system is likely to produce gusty winds and 
dangerous surf and rip current conditions along portions of the 
southeastern United States coast late this week and into the 
weekend. Heavy rainfall is expected in portions of the Carolinas 
with hazardous marine conditions expected over the coastal and 
offshore waters where gale warnings are in effect. For more 
information, see products from your local National Weather 
Service office and high seas forecasts issued by the National 
Weather Service.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...10 percent.

High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFAT1, WMO header FZNT01 
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php

Forecaster Brown
000
AXNT20 KNHC 251022
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Thu May 25 2023

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through 
1015 UTC.

...SPECIAL FEATURES...

W Atlantic Gale Warning: The 1007 mb low pressure system near SW 
coast of Florida is forecast to strengthen and drift over the 
western Atlantic through Sat. The system will then move north 
through Sat night. The pressure gradient between the high pressure
over the eastern U.S. and the low will support fresh to strong NE
winds and large NE swell across the NE Florida offshore waters 
beginning Thu night, spreading southward to near Daytona Beach Fri
through Sat. NE gales are expected offshore northern Florida 
beginning on Fri evening and continue through the night. Seas will
build to near 15 ft Fri night. Winds and seas will diminish late 
Sat into Sun as the low moves north of the area. 

Please, see the latest NWS High Seas Forecast issued by National 
Hurricane Center at website 
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further 
details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis along 23W, 
south of 12N, moving westward around 5 kt. Scattered moderate 
convection is noted south of 11N and east of 28W.

Another eastern Atlantic tropical wave has its axis along 34W, 
south of 12N, moving westward around 10 kt. No significant
convection is noted with this wave at this time.

A central Atlantic tropical wave has its axis along 49W, south of
12N, moving westward around 10 kt. No significant convection is 
noted near the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Africa near 09N13W to 05N28W. The ITCZ extends from 05N28W to 
05N33W, then from 04N35W to 04N49W, and then from 05N50W to 
08N59W. All significant convection is described in the tropical 
wave section above.

GULF OF MEXICO...

Refer to the Special Features section above for information about
the low currently centered over the SW Gulf.

The combination of the low pressure near the SW coast of Florida,
ample moisture, and divergence aloft is enhancing scattered 
showers over the eastern half of the basin. A weak high pressure 
regime dominates the rest of the Gulf waters. Moderate to fresh 
easterly winds are noted N of 28N and E of 90W. Similar N-NE winds
are noted in the eastern Bay of Campeche. Seas in the regions 
described are 2-3 ft. Elsewhere, light to gentle anticyclonic 
winds and slight seas prevail. Haze is noted over most of the 
central and western Gulf sections due to agricultural fires in 
southern Mexico and in Central America.

For the forecast, the moderate to fresh winds over the NE gulf
waters will prevail through Sat morning. Otherwise, weak high 
pressure will dominate the basin through the next several days, 
supporting gentle to moderate winds. Slight seas will build to 
moderate through Sat. Popocatepetl Volcano in Mexico near 19N99W 
remains in a state of unrest and continues to erupt and produce 
volcanic ash, however the current ash plume is confined inland. 
Mariners should still exercise caution in the southern Bay of 
Campeche in case additional, and more northward plumes develop. If
mariners encounter volcanic ash or floating volcanic debris, you 
are encouraged to report the observation to the National Weather 
Service by calling 305-229-4424.  

CARIBBEAN SEA...

Aside from the scattered showers and isolated thunderstorms in 
the Windward Passage and off northern Colombia, mainly dry 
conditions prevail across the basin. The subtropical ridge 
extends weakly into the basin, supporting moderate easterly winds 
in the eastern Caribbean and primarily light to gentle winds 
elsewhere. Seas of 2-4 ft are occurring in the eastern Caribbean 
and 1-2 ft elsewhere. Haze is present over the northwestern 
Caribbean due to agricultural fires in Central America.

For the forecast, elongated troughing N of the basin will help to
maintain a weak pres gradient across the central and western 
Caribbean today, supporting light to gentle winds. A trough will 
prevail across the NW Caribbean through the end of the week, 
leading to a slight increase in winds and seas. Over the E 
Caribbean, the Azores High will support gentle to moderate E-SE 
trade winds through the weekend, diminishing slightly into early 
next week.

ATLANTIC OCEAN...

Please read the Special Features section for more details on the 
developing gale force low in the western Atlantic.

A 1007 mb low pressure is centered near SW Florida. A surface
trough extends from the low near 25N81W to 28N76W. Abundant 
tropical moisture and divergence aloft results in a broad area of 
scattered showers and thunderstorms between 63W and Florida and 
north of the Greater Antilles. A recent scatterometer pass depict 
fresh to strong winds associated with the strongest storms. 
Farther east, a surface trough extends from 29N33W to 19N31W with
no significant convection at this time. 

The rest of the tropical Atlantic is dominated by an extensive
subtropical ridge positioned well north of the Azores. Moderate 
to fresh E-SE winds are found between mainly 35W and 67W. Wave 
heights in these waters are 5-8 ft. Moderate or weaker winds and
moderate seas prevail elsewhere in the basin.

For the forecast W of 55W, the low pres is forecast to strengthen
and drift over the W Atlc then move N through Sat night. The pres
gradient between high pres over the eastern U.S. and the low will
support fresh to strong NE winds and large NE swell across the NE
Florida offshore waters beginning tonight, spreading southward to
near Daytona Beach Fri through Sat before the low moves N of the 
area. NE gales are expected offshore northern Florida Fri night. 

$$
ERA
GFS ENSEMBLE MEMBER SHOWS LOW BUT NOTHING SIGNIFICANT LIKE A STRONG 
TROPICAL STORM OR HURRICANE.

ENSEMBLE ARE SHOW THE LOW APRAOCHING THE COAST BUT NOT AS A TROPICAL SYSTEM.
MOSTLY GUSTY WINDS AND HEAVY RAINS

EURO (ECMWF) MODEL 

CANADIAN (GEM) MODEL

AMERICAN (GFS) MODEL

YOU CAN SEE AS HEAVY RINS ARE OFF SHORE AND THEN MOVE INLAND BY SAT-MONDAY.

MARGINAL EXCESSIVE RAINFALL FOR FLORIDA SLIGHT/MARGINAL FOR THE CAROLINAS
DURING THE NEXT 5 DAYS.  FLOODING WILL BE THE MAJOR CONCERN WITH THIS LOW.

SURFACE FRONTS AND SEA-LEVEL PRESSURES WEATHER PREDICTION CENTER





Wednesday, May 24, 2023

..NATIONAL HURRICANE POST A NEW STORM INVEST OFF THE CAROLINA COAST..

 


THE POSSIBLE LOW I WAS MENTIONING THIS MORNING IS NOW A STORM INVESTIGATION WITH A LOW 10% FORMATION WITHI 7 DAYS.

RTW


ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Wed May 24 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. Southwestern Atlantic:
A non-tropical area of low pressure is expected to form along a 
front offshore of the southeastern United States coast during the 
next day or two. The system appears unlikely to become a subtropical 
or tropical cyclone since it is forecast to remain frontal while 
moving generally northward and inland over the Carolinas this 
weekend.

Regardless, the system is likely to produce gusty winds and 
dangerous surf and rip current conditions along portions of the 
southeastern United States coast late this week and into the 
weekend. Heavy rainfall is expected in portions of the Carolinas, 
and hazardous marine conditions are expected over the coastal and 
offshore waters where gale watches and warnings are in effect. For 
more information, see products from your local National Weather 
Service office and high seas forecasts issued by the National 
Weather Service.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...10 percent.

High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFAT1, WMO header FZNT01 
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php

Forecaster Reinhart

YOU CAN SEE ALL THE STORMS AND LIGTHNING DEVELOPING OVER FLORIDA SETTING UP A STORMY PATTERN, BEFORE THE LOW TRACKS OFF SHORE FRIDAY THROUGH SUNDAY, AND APPROACHES THE CAROLINA COAST.  LOOKS LIKE A SOGGY MEMORIAL DAY FOR THE CAROLINAS ON MONDAY.


..TROPICAL WEATHER OUTLOOK MAY 24, 2023..


MODELS ARE STILL SHOWING LOW PRESSURE DEVELOPING OVER FLORIDA AND EVENTUALLY MOVING OFF SHORE THE EAST COAST AND TRACKING TOWARD THE CAROLINAS.  NOW MODELS ARE HINTING AT THE POSSIBILITY THAT THIS LOW COULD MOVE INLAND OVER THE CAROLINAS AS A WEAK DEPRESSION OR TROPICAL STORM.

REGARDLESS OF DEVELOPMENT THIS COULD BRING HEAVY RAINS AND FLOODING TO FLORIDA  AND THE CAROLINAS. 

SOME OF THE CELLS COULD REACH SEVERE LIMITS AND PRODUCE DAMAGING WINDS, LIGHTINING, HAIL AND HEAVY DOWNPOURS.  THIS IS IN TODAYS FORECAST FOR FLORIDA, THIS AFTERNOON AND EVENING, AND DURING THURSDAY BEFORE THIS LOW MOVES OFF SHORE THE EAST COAST. 

RTW

NATIONAL HURRICANE CENTER TROPICAL OUTLOOK


 000

ABNT20 KNHC 241134
TWOAT 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed May 24 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Reinhart
ATLANTIC TROPICAL WEATHER DISCUSSION!

000

AXNT20 KNHC 241013
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed May 24 2023

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through 
0930 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 30W, south 
of 12N. It is moving westward around 10 kt. Scattered moderate to
strong convection is observed from 06.5N to 10N and between 24W 
and 32W. 

A central Atlantic tropical wave has its axis along 46W, south of
11N. It is moving westward around 10 kt. Scattered moderate  
isolated strong convection is present from 00N to 09N between 40W
and 48W. 

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of Guinea
near 10N15W and continues to 05.5N23W. The ITCZ extends from 
05.5N23W to 06.5N29W, then from 06N32W to 06.5N44W, and finally 
resumes from 07N47W to 07.5N58W. Other than convection noted 
above with the tropical waves, scattered moderate isolated strong 
convection is noted from 00N to 07N between 10W and 23W.

GULF OF MEXICO...

Dispersing volcanic ash from recent eruptions of Popocatepetl 
Volcano in Mexico has shifted southeastward and dispersed over
land, and is not currently detected over the waters of the Gulf.

A stationary front extends along 29N this morning, from the
Florida Big Bend to the coastal waters of SW Louisiana. Widely
scattered showers and isolated thunderstorms within 90 nm of the 
coasts near the front. Other widely scattered moderate convection
is farther SE, from 26N to 28N and E of 87W to the Florida west
coast. The remainder of the Gulf of Mexico is under the influence
of a weak 1014 mb high pressure centered over the NW Gulf. 
Surface observations and overnight scatterometer satellite data 
indicate light to gentle anticyclonic winds across the basin, 
except for moderate to fresh N-NE winds off the northern and 
western coast of Yucatan. The satellite-derived winds and recent
buoy observations also show that the strongest convection in the 
NE Gulf has produced brief periods of fresh to strong NE to E 
winds, and seas briefly to 5 ft. Wave heights, otherwise, are 2 
ft or less in the Gulf except around 3 ft near the NW Yucatan.

For the forecast, the stalled front across the N Gulf will move S
through the eastern Gulf this afternoon through Fri, followed by 
moderate to locally fresh N to NE winds E of 90W through Sat 
morning. Otherwise, weak high pressure will generally dominate the
basin through the week, yielding light to gentle winds through 
tonight, and gentle to moderate thereafter. Seas are presently 
slight, but will build with the increasing winds behind the front.

CARIBBEAN SEA...

Water vapor satellite imagery depicts an upper level low north of
the Lesser Antilles with a broad trough extending S-SW to the
coast of Venezuela. This is generating a cluster of scattered showers
and moderate thunderstorms affecting the NE Caribbean N of 17N and
adjacent islands. The rest of the Caribbean Sea is under fairly 
tranquil weather conditions, except for scattered moderate
convection across the entrance to the Windward Passage. Satellite
imagery also show hazy skies over parts of the NW Caribbean, 
associated with the ash sent into the atmosphere in recent days by
the volcano Popocatepetl in central Mexico.

High pressure centered across the NE Atlantic extends a broad
ridge SW to the Atlantic along about 68W. This pattern is
producing moderate easterly trade winds in the SE Caribbean, 
while light to moderate breezes prevail elsewhere. Seas of 3-4 ft
are evident in the central and eastern Caribbean, while 1-2 ft 
seas are prevalent in the rest of the basin.

For the forecast, the elongated low pressure across the Atlantic will
help to maintain a weak pres gradient across the central and 
western Caribbean through Thu, supporting light to gentle winds. A
pre-frontal trough will move into the NW Caribbean Thu night, 
where it will stall and linger through the end of the week, 
leading to a slight increase in winds and seas there. Over the E 
Caribbean, the ridge associated with the Azores High will support
gentle to moderate E-SE trade winds through the forecast period, 
locally fresh offshore northern Venezuela. Dispersing volcanic ash
from recent eruptions of Popocatepetl Volcano in Mexico have 
shifted across the Yucatan Peninsula and into the NW Caribbean W 
of 83W, and are expected to linger through this morning. 

ATLANTIC OCEAN...

A 1007 mb low pressure center continues to move N-NE this morning,
and is located near 29.5N70.5W, with a trough trailing SW to near
24N74W. Scattered moderate isolated strong convection is seen 
east of the trough to 62W and north of 25N. Overnight 
scatterometer satellite data showed moderate to locally strong 
southerly winds north of 25N and between the surface trough and 
62W. Seas in these waters are 6-9 ft, as reflected in the latest 
altimeter satellite data. Farther west, a stationary front is NW
of the low, and extends from 31N73W to north Florida along 29N. 
Scattered moderate convection is present across the Straits of
Florida, and from the NW Bahamas to offshore of the coast of
Georgia. 

The remainder of the tropical Atlantic is dominated by a broad
subtropical ridge positioned in the far NE Atlantic that extends
southwestward to 68W. An upper level low north of the Leewards
continues to enhance convection over the islands and nearby 
waters. The pressure gradient between the ridge and lower 
pressures in the deep tropics sustains moderate to fresh easterly 
trade winds over most of the central and eastern Atlantic, with 
the highest winds occurring well east of the Leewards. Seas in the
waters described are 6-8 ft. Elsewhere, moderate or weaker winds 
and moderate seas prevail.

For the forecast W of 55W, the low center near 29.5N70.5W will 
move N-NE and just N of the area by midday, where it will begin 
to interact with a weak cold front approaching from the NW, then 
move well NE and exit the region tonight. Fresh to strong SE 
winds, rough seas, with scattered showers and tstms will prevail E
of the low and trough through this evening. A broad middle to
upper level trough across the SE U.S will dig SE across the
Florida Peninsula over the next couple of days. This will help to
generate new surface low pressure over central Florida late 
today, then move N-NE off the peninsula Thu, and across the far 
NW waters through Sat. Active weather will accompany this
developing feature W of 70W. The pres gradient between high pres 
over the eastern U.S. and the low will support fresh to locally 
strong NE winds and large NE swell across the NE Florida offshore 
waters beginning Thu night and spreading southward to near Daytona
Beach Fri through Sat, before the low moves N of the area. NE 
gales are possible offshore of Jacksonville, Florida Fri night.

$$
Stripling

EURO (ECMWF) MODEL SHOWS LOW PRESSURE AND RAINS WITH GUSTY WINDS MOVING INLAND SOUTH CAROLINA.


AMERICAN MODEL (GFS) SHOWS AND DEPRESSION MOVING INLAND OVER THE GEORGIA SOUTH CAROLINA BORDER AS A DEPRESSION MAYBE A LOWER LEVEL TROPICAL STORM.

CANADIAN (GEM) MODEL ALSO SHOWS LOW TRACKING INLAND OVER SOUTH CAROLINA.

NAVY (NAVGEM) MODEL ALSO SHOWS A POSSIBLT DEPRESSION MOVING INLAND SOUTH CAROLINA.

GERMAN (ICON) MODEL SHOW TROPICAL STORM WITH GUSTY WINDS AND HEAVY RAINS MOVING INLAND SOUT/NORTH CAROLINA BORDER.

GFS ENSEMBLE MEAN MEMBER MOST DEFINITELY SHOW PROBAILITY OF LOW PRESSURE/ STORM COMING OUT OF FLORIDA.


EURO ALSO SHOWS A POSSIBLE DEPRESSION OR TROPICAL STORM TRACKING INLAND OVER THE CAROLINAS. 


SEVEN DAY RAINFALL OUTLOOK.. RAINS WEDNSDAY THROUGH FRIDAY BECOMING LESS BY SATURDAY AND SUNDAY FOR FLORIDA .


EXCESSIVE RAINFALL OUTLOOK


SURFACE FRONTS AND SEA-LEVEL PRESSURES




Tuesday, May 23, 2023

..TROPICAL WEATHER OUTLOOK MAY 23, 2023..

 


THE TROPICS REMAIN QUIET, HOWEVER, A FRONTAL BOUNDARY  THAT WILL DROP OVER FLORIDA WILL BE ACCOMPANIED BY LOW PRESSURE AND THIS WILL HELP TO INCREASE SHOWERS AND STORMS OVER FLORIDA IN THE COMING DAYS.  

SOME OF THESE CELLS COULD BE STRONG TO SEVERE AT TIMES AND PRODUCE HEAVY RAINS THAT CAN CAUSE FLOODING IN THOSE FLOOD PRONE AREAS.

GUSTY WINDS, HAIL AND LIGTHNING ARE POSSIBLE AND AS USUAL WITH SEVERE STORMS YOU CAN'T RULE OUT WATER SPOUTS, FUNNEL CLOUDS OR ISOLATED TORNADO.  

THIS LOW WILL EVENTUALLY MOVE OFF SHORE THE EAST COAST OF FLORIDA AND COULD MOVE NORTH TOWARD GEORGIA CAROLINA COAST, AND ENHANCE RAINS AND STORMS ALONG THE COAST.

I WILL CONTINUE TO MONITOR AND REPORT HERE AS NEEDED!

RTW

NATIONAL HURRICANE CENTER


331 
ABNT20 KNHC 231137
TWOAT 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Tue May 23 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Reinhart
SURFACE ANALYSIS MAP AND TROPICAL OUTLOOK DISCUSSION 
COURTESY OF THE NATIONAL HURRICANE CENTER
000
AXNT20 KNHC 231033
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Tue May 23 2023

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through 
0930 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Ashfall Advisory: The Popocatepetl Volcano in
Mexico continues in an active state of unrest. Ash from recent 
large eruptions has moved E-NE as far as the Yucatan Peninsula. 
Ash from more recent moderate eruptions is reaching as high as 
30000 ft. Upper-level westerly winds are transporting the ash 
across the adjacent SW Gulf of Mexico, S of 20N and west of 93W, 
and is expected to reach 91W by morning. Mariners who encounter 
volcanic ash or floating volcanic debris are encouraged to report 
this observation to the National Hurricane Center, by calling 
+1-305-229-4424.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 26W, south
of 12N. It is moving west at 10 kt. Scattered moderate to strong 
convection is observed from 05N to 09N and between 21W and 28W.

Another eastern Atlantic tropical wave has its axis along 42W,
south of 10N. It is moving westward at 10 kt. Scattered moderate 
to strong convection is present from 04N to 09.5N between 39W and
46W.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Guinea-Bissau near 11N15W and continues to 08N20W. The ITCZ 
extends from 08N20W to 07.5N25W, then resumes from 07N27W to 
06N40W, and then resumes again from 06N43W to the coast of Guyana
at 07.5N59W. Scattered moderate isolated strong convection is 
seen from 01.5N to 07N between 07W and 17W. Outside of convection
described with the tropical waves, scattered moderate to strong
convection is noted within 120 nm N and 60 nm S of the ITCZ 
between 28W and 47W.

GULF OF MEXICO...

Please read the Special Features section for information on the 
Ashfall Advisory for the SW Gulf of Mexico. 

An outflow boundary has moved west-southwestward across much of
the NE Gulf overnight, and has recently reached from Lake
Pontchartrain to just north of Tampa Bay. The passage of this
boundary has triggered scattered moderate convection that lingers
from 27N to 29N between 85W and 89W. The rest of the basin is 
dominated by a weak high pressure system centered over the NW
Gulf. Surface observations and a recent scatterometer satellite 
pass show light to gentle anticyclonic winds prevailing over most 
of the Gulf, except for localized fresh winds off the Big Bend 
region of Florida, behind the outflow boundary, and in the 
eastern Bay of Campeche. Seas are 1-3 ft across the Gulf waters.

For the forecast, weak high pressure will generally dominate the basin
through the week, yielding light to gentle winds and slight seas. 
A modest cold front will move S through the eastern Gulf
late Wed through Thu, followed by moderate to locally fresh N to
NE winds E of 90W through Sat morning. Popocatepetl Volcano in
Mexico near 19N99W has been active since Sun and continues to
erupt this morning. Ash has moved E to NE away from the volcano
and over the Bay of Campeche, S of 22N and W of 90W. Visibility
may be restricted in this area due to volcanic ashfall through
tonight. Mariners should exercise caution.  

CARIBBEAN SEA...

An upper level trough extends from the western Atlantic S-SE
across the Mona Passage into the NE Caribbean, and is shifting
slowly eastward. This feature is supporting scatted showers and
isolated thunderstorms from eastern Puerto Rico, east and
southeast across the eastern Caribbean, the Lesser Antilles, and
to the Atlantic waters W of 5W. The rest of the Caribbean Sea 
experiences generally dry conditions. The weak pressure regime 
maintains gentle to moderate easterly trade winds in the central 
and eastern Caribbean, while light to gentle easterly breezes are 
found in the remainder of the basin. Seas are slight to moderate 
across the Caribbean.

For the forecast, elongated low pressure extending from the SE 
Bahamas to near 30N70W will lift N-NE and exit the region early 
Wed. Low pressure is then expected to develop over central Florida
Wed night and move slowly NE through Sat. This pattern will 
maintain a weak pressure gradient across the central and western 
Caribbean through Sat, supporting light to gentle winds. Over the 
E Caribbean, the Azores High ridge will support gentle to moderate
SE trade winds through the forecast period. Expect scattered 
showers and thunderstorms across the waters between 65W and 55W 
through Tue night. 

ATLANTIC OCEAN...

A surface trough extends from low pressure near Bermuda through 
1008 mb low pressure near 25.5N71.5W to offshore of Haiti near 21N71W.
An upper level trough across the western Atlantic W of 70W and
extends S-Se through the MOna Passage. This deep layered feature
is supporting scattered moderate to isolated strong convection  
to the east of the surface trough to west of 63W, and north of 
22N. Overnight scatterometer satellite data depicted fresh 
northerly winds within 180 nm of the low in the W and NW 
quadrants. Gentle to moderate winds, in cyclonic fashion, are 
noted elsewhere within 360 nm of the low and trough. Seas of 6-9 
ft are present over the waters north of 22N and east of the 
Bahamas to 60W. Farther west, a weak stationary front is along
about 31N and reaches NE Florida, where and a few thunderstorms 
are seen near the boundary.

The remainder of the tropical Atlantic is dominated by an
extensive subtropical ridge positioned north of the Azores. The
pressure gradient is supporting moderate to fresh easterly winds 
over most of the central and eastern Atlantic waters. Localized 
strong winds are evident in the areas of the ITCZ where strong 
convection resides. Moderate seas of 6 to 8 ft are prevalent in 
the central and eastern Atlantic. Elsewhere in the basin, moderate
or weaker winds and moderate seas prevail.

For the forecast W of 55W, the elongated low pressure will move 
N-NE and reach near 30N70W early Wed, when it will interact with a
weak cold front approaching from the NW, then move NE and exit 
the region Wed night. Fresh to strong SE winds, rough seas, with 
scattered showers and tstms will prevail E of the low and trough 
through Wed. New low pressure is forecast to develop over central 
Florida late Wed, move N-NE off the peninsula Thu, and across the 
far NW waters through Sat. The pressure gradient between high 
pressure over the eastern U.S. and the low will support fresh to 
locally strong NE winds and large NE swell across the NE Florida 
offshore waters beginning Thu night through Sat. Gale-force NE
winds are possible late Fri across these waters.

$$
Stripling
EURO ENSEMBLE MODEL
EURO ENSEMBLE NOT SHOWING MUCH ACTIVITY, 
BUT IT DOES SHOW THE A LOW OF TH CAROLINA COAST.

THE GFS AMERICAN MODEL CONTINUES TO TRACK LOWS 
OVER FLORIDA AND NORTHEAST TOWARD THE GEORGIA/CAROLINA. 





EURO MODEL AVERAGE PRECIPITATION RATE
(DARKER GREEN MODERATE, YELLOWS AND REDS HEAVIER).


GFS MODEL SHOWS MUCH MORE PRECIPITION AND SEVERAL VOTICIES!


CANADIAN MODEL SHOW PRECIPITATION OVER
FLORIDA BUT NOT AS MUCH AS THE GFS.



THE GERMAN ICON MODEL ALSO SHOWS PRECITATION OVER FLORIDA.

THE NAVY NAVGEM MODEL ALSO SHOWS PRECIPITATION AND MULTIPE LOWS.


WPC DAY 15 QUANTITATIVE PRECIPITATION FORECAST SHOWS RAINS
THROUGH THURSDAY AND BEGINNING TO DECREASE BY SATURDAY.

DAYS 1-5 EXCESSIVE RAINFALL OUTLOOK SHOW A MARGINAL RISK FOR FLORIDA DAYS 1-2
WPC NATIONAL FORECAST CHARTS SHOWS FRONT AND A GULF LOW PRESSURE 
CROSSING STATE AND EXITING INTO THE ATLANTIC WITH RAIN 
AND THUNDERSTORMS CHANCE DAYS 1-3.

WPC SURFACE FRONTS AND SEA-LEVEL PRESSURES CHART
SHOWS THE PROGRESSION OF THE FRONT/LOW 
AND RAIN AND STORM CHANCES.







Monday, May 22, 2023

Mesoscale Precipitation Discussion: #0323 (Issued at 214 PM EDT Mon May 22 2023 )

 


Mesoscale Precipitation Discussion 0323
NWS Weather Prediction Center College Park MD
214 PM EDT Mon May 22 2023

Areas affected...Central Florida Peninsula...

Concerning...Heavy rainfall...Flash flooding possible

Valid 221815Z - 230000Z

SUMMARY...Colliding outflow boundaries from sea-breeze
thunderstorms, to result in rapid slab up/downdraft with potential
for 3+"/hr and possible rapid inundation flooding.

DISCUSSION...Above average moisture and proximity to stronger than
normal mid to upper level flow favorable to maintain updraft
strength resides across northern FL into the northern Peninsula. 
As such stronger than normal sea breeze convergence is starting to
occur with new cells developing along both coasts.  Very strong
updrafts (see MCD 836 from SPC) with 1500-2000 MLCAPE and ample
low level moisture (near 2" total PWat) should allow for efficient
rainfall production.  Though there is some modest mid-level dry
air to allow for some cold pool generation.  Weak steering flow
may allow for localized 2-3" totals in short-period but it is the
outflow dominance with the sea breeze convection that should aid
secondary development along the outflow boundaries.

Propagation inward across the peninsula will enhance and
strengthen moisture flux convergence into the next round and
eventually will lead to those larger outflow boundary collisions.
As a result a much larger/broader updrafts or slab ascent will
result in very high moisture loading to those updrafts.  Given 2"
total PWat and convergence values, 2.5-3.5"/hr rates are quiet 
possible, though much may fall in sub-hourly duration.  Localized
2-5" totals across the north-central peninsula in proximity to the
urban corridor resulting in localized rapid inundation flooding
conditions mainly between 21-00z.  Hi-Res CAMs support this
evolution unzipping from north-central toward Lake Okeechobee with
time as HREF probabilities range between 10 to 30% for 3"/hr and
as high as 80% for 3"/3hr from Marion to Polk county by 00z.  Thus
adding confidence in the above normal potential today versus
average sea-breeze convective days and making flooding considered
possible this afternoon across the central Peninsula.

Gallina

..BAHAMA SYSTEM LOWERED TO 0% CHANCE FOR FORMATION..

 


THE NATIONAL HURRICANE CENTER LOWER FORMATION CHANCES TO 0% WITH THE TROUGH OF LOW PRESSURE NEAR THE BAHAMAS.

000
ABNT20 KNHC 221742
TWOAT 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon May 22 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Southwestern Atlantic:
Disorganized showers and a few thunderstorms associated with a broad 
area of low pressure located a couple of hundred miles northeast of 
the central Bahamas have decreased since yesterday. Environmental 
conditions have become more hostile and development of this system 
is not expected while it moves north-northeastward at 5 to 10 mph 
over the southwestern Atlantic during the next day or so.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...near 0 percent.

$$
Forecaster Brown/Bucci


UPPER LEVEL SHEAR ON THE INCREASE OVER THIS AREA, THIS IS WHAT EL NINO DOES TO 
DEVELOPING SYSTEMS IT SHREADS THE CLOUDS APART, LOOK AT ALL SHEAR IN THE RED COLOR!