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Tropical Disturbance May Develop off Southeast U.S. Coast by Monday

By: Dr. Jeff Masters, 2:55 PM GMT on June 27, 2014

A blow-up of thunderstorms over Texas and Louisiana on Wednesday created an area of low pressure that tracked east-northeast over the Southeast U.S., and was over Georgia and South Carolina on Friday. This low will emerge over the coastal South Carolina waters on Saturday, and move over the warm waters of the Gulf Stream current by Sunday. Sea surface temperature in this region are about 1°C above average, 27 - 28°C, which is plenty of heat energy for a developing tropical cyclone. Wind shear is moderate, 10 - 20 knots, and is forecast to remain moderate through Monday. These conditions favor development, though the 00Z Friday runs of our reliable tropical cyclone genesis models--the GFS, European, and UKMET--did not show development into a tropical depression. The disturbance will be in an area of weak steering currents, and the predominant track favored by the models is a slow south and then southwest movement towards Florida. The latest thinking from NOAA's Weather Prediction Center (Figure 1) is that the disturbance will bring a swath of 2 - 4" of rain from North Carolina to Florida during the coming week. These rainfall totals will be higher if the disturbance develops into a tropical depression. However, the system may not have much time over water before moving ashore over Florida on Monday, if the 00Z and 06Z Friday runs of the GFS model are correct. In their 8 am EDT Friday Tropical Weather Outlook, NHC gave the system 2-day and 5-day odds of development of 0% and 20%, respectively.


Figure 1. Predicted precipitation for the 7-day period ending on Friday, July 4, 2014. A tropical disturbance off the Southeast U.S. coast is predicted to create a swath of 2 - 4 inches of rain from North Carolina to Florida. Image credit: NOAA's Weather Prediction Center.


Figure 2. There's nothing cooking off the coast of Africa: the tropical Atlantic was dominated by stable stratocumulus clouds and was free of heavy thunderstorm activity in this MODIS image taken on Friday morning, June 27, 2014. The murky appearance of this image is due to Saharan dust sweeping westwards off the coast of Africa. In the lee of the Cape Verde Islands, we can see beautiful Kármán vortex street clouds--a repeating pattern of swirling vortices caused by the unsteady separation of flow of air around the islands. The phenomenon is named after the engineer and fluid dynamicist Theodore von Kármán. Image credit: NASA.

Have a great weekend, everyone, and I'll have at least one update over the weekend.

Jeff Masters

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Quoting 495. HurricaneAndre:

We have invest 91L.


91L has a nice anticyclonic flow developing aloft.

we have invest 91L NOW!!
AL, 91, 2014062712, , BEST, 0, 343N, 813W, 15, 1016, DB, 0, , 0, 0, 0, 0,
AL, 91, 2014062718, , BEST, 0, 338N, 807W, 15, 1016, DB, 0, , 0, 0, 0, 0,
AL, 91, 2014062800, , BEST, 0, 334N, 801W, 15, 1016, DB, 0, , 0, 0, 0, 0,
AL, 91, 2014062806, , BEST, 0, 329N, 794W, 15, 1016, DB, 0, , 0, 0, 0, 0,
AL, 91, 2014062812, , BEST, 0, 325N, 786W, 20, 1016, DB, 34, NEQ, 0, 0, 0, 0, 1018, 100, 60, 0, 0, L, 0, , 0, 0, INVEST, S,
What is the ships forecast for 91L.
1 KWBC 281242
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1242 UTC SAT JUN 28 2014

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL912014) 20140628 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS... ...36 HRS...
140628 1200 140629 0000 140629 1200 140630 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 32.5N 78.6W 32.1N 78.7W 31.6N 79.0W 31.1N 79.3W
BAMD 32.5N 78.6W 32.1N 78.5W 31.7N 78.9W 31.4N 79.2W
BAMM 32.5N 78.6W 32.2N 78.5W 31.8N 78.8W 31.4N 79.1W
LBAR 32.5N 78.6W 32.1N 77.5W 31.6N 76.5W 31.2N 75.7W
SHIP 20KTS 24KTS 27KTS 32KTS
DSHP 20KTS 24KTS 27KTS 32KTS

...48 HRS... ...72 HRS... ...96 HRS... ..120 HRS...
140630 1200 140701 1200 140702 1200 140703 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 30.7N 79.8W 30.4N 80.9W 30.6N 81.8W 31.6N 81.9W
BAMD 31.2N 79.6W 31.0N 80.8W 31.7N 82.1W 33.5N 81.9W
BAMM 31.1N 79.4W 30.9N 80.4W 31.3N 81.4W 32.7N 80.9W
LBAR 30.9N 75.0W 31.0N 73.5W 32.2N 72.4W 35.0N 71.1W
SHIP 36KTS 43KTS 47KTS 51KTS
DSHP 36KTS 43KTS 41KTS 29KTS

...INITIAL CONDITIONS...
LATCUR = 32.5N LONCUR = 78.6W DIRCUR = 125DEG SPDCUR = 7KT
LATM12 = 33.4N LONM12 = 80.1W DIRM12 = 129DEG SPDM12 = 7KT
LATM24 = 34.3N LONM24 = 81.3W
WNDCUR = 20KT RMAXWD = 60NM WNDM12 = 15KT
CENPRS = 1016MB OUTPRS = 1018MB OUTRAD = 100NM SDEPTH = S
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
Quoting Autistic2:
Gulf Stream = unlimited fresh warm or hot water. I was 9 miles offshore of St. Aug yesterday. Water temp was steady between 85-84.5 with no thermoclines present. That's 90-100 feet of water at a constant temp all the way down. My brother went to the outer Plane reefs (23 miles out). 83 degrees with no thermoclines. 150 feet with no cold water

Code orange, FL shields to max please. Code Red at 5?


Warm water is only one factor needed. The water from N.C. down to Florida is warm enough to support a tropical system. It's all the other factors that need to fall into place.

We've had plenty of Lows in the GOM with water temps near 90 degrees and nothing forms because of shear or dry air, etc.
The upper level environment will be the key factor in the development of this system.

Quoting Tropicsweatherpr:
1 KWBC 281242
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1242 UTC SAT JUN 28 2014

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL912014) 20140628 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS... ...36 HRS...
140628 1200 140629 0000 140629 1200 140630 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 32.5N 78.6W 32.1N 78.7W 31.6N 79.0W 31.1N 79.3W
BAMD 32.5N 78.6W 32.1N 78.5W 31.7N 78.9W 31.4N 79.2W
BAMM 32.5N 78.6W 32.2N 78.5W 31.8N 78.8W 31.4N 79.1W
LBAR 32.5N 78.6W 32.1N 77.5W 31.6N 76.5W 31.2N 75.7W
SHIP 20KTS 24KTS 27KTS 32KTS
DSHP 20KTS 24KTS 27KTS 32KTS

...48 HRS... ...72 HRS... ...96 HRS... ..120 HRS...
140630 1200 140701 1200 140702 1200 140703 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 30.7N 79.8W 30.4N 80.9W 30.6N 81.8W 31.6N 81.9W
BAMD 31.2N 79.6W 31.0N 80.8W 31.7N 82.1W 33.5N 81.9W
BAMM 31.1N 79.4W 30.9N 80.4W 31.3N 81.4W 32.7N 80.9W
LBAR 30.9N 75.0W 31.0N 73.5W 32.2N 72.4W 35.0N 71.1W
SHIP 36KTS 43KTS 47KTS 51KTS
DSHP 36KTS 43KTS 41KTS 29KTS

...INITIAL CONDITIONS...
LATCUR = 32.5N LONCUR = 78.6W DIRCUR = 125DEG SPDCUR = 7KT
LATM12 = 33.4N LONM12 = 80.1W DIRM12 = 129DEG SPDM12 = 7KT
LATM24 = 34.3N LONM24 = 81.3W
WNDCUR = 20KT RMAXWD = 60NM WNDM12 = 15KT
CENPRS = 1016MB OUTPRS = 1018MB OUTRAD = 100NM SDEPTH = S
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
thanks.
Recon scheduled for Invest 91L off the coast of NE Florida. Mission 1 scheduled for wheels up at 29/1545Z or Sunday at 11:45 am EDT. - Mike Adcock
Plan of the Day

000 NOUS42 KNHC 281239 REPRPD WEATHER RECONNAISSANCE FLIGHTS CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL. 0835 AM EDT SAT 28 JUNE 2014 SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD) VALID 29/1100Z TO 30/1100Z JUNE 2014 TCPOD NUMBER.....14-028 I. ATLANTIC REQUIREMENTS 1. SUSPECT AREA (OFF THE COAST OF NE FLORIDA) FLIGHT ONE -TEAL 71- A. 29/1800Z B. AFXXX 01BBA INVEST C. 29/1545Z D. 30.0N 78.0W E. 29/1745Z TO 29/2200Z F. SFC TO 10,000 FT. FLIGHT TWO -TEAL 72- A. 30/1200Z B. AFXXX 0201A CYCLONE C. 30/0930Z D. 29.5N 78.0W E. 30/1145Z TO 30/1600Z F. SFC TO 10,000 FT 2. SUCCEEDING DAY OUTLOOK: CONTINUE 12-HRLY FIXES IF SYSTEM DEVELOPS. II. PACIFIC REQUIREMENTS 1. NEGATIVE RECONNAISSANCE REQUIREMENTS. 2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE. $$ JWP
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0835 AM EDT SAT 28 JUNE 2014
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 29/1100Z TO 30/1100Z JUNE 2014
TCPOD NUMBER.....14-028

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (OFF THE COAST OF NE FLORIDA)
FLIGHT ONE -TEAL 71-
A. 29/1800Z
B. AFXXX 01BBA INVEST
C. 29/1545Z
D. 30.0N 78.0W
E. 29/1745Z TO 29/2200Z
F. SFC TO 10,000 FT.

FLIGHT TWO -TEAL 72-
A. 30/1200Z
B. AFXXX 0201A CYCLONE
C. 30/0930Z
D. 29.5N 78.0W
E. 30/1145Z TO 30/1600Z
F. SFC TO 10,000 FT

2. SUCCEEDING DAY OUTLOOK: CONTINUE 12-HRLY FIXES
IF SYSTEM DEVELOPS.
Even that last tiny blob east of Cape Canaveral started going tropical before shear blew it away, so the energy is there waiting to be tapped. The further south our new invest gets, the longer it will fester over the warm Gulf Stream waters before the next trough picks it up. It is under some N/NE shear now from the flow between the Gulf high and the ULL to its south and southwest, but there will be a lull in shear as the next trough approaches... so the key for my interest and my natural bias living on the Space Coast is to watch: how far south?
For any newcomers on this year here is a fabulous page to go on to get recon data.

www.tropicalatlantic.com
91l...

Morning to all. The current T wave approaching S.A. may end up being a rain maker for the islands.

The Carolina disturbance has gone from shrimp shaped blob to invest.. It's now 91L.. Winds are 20kts.. Off land & this far south it could strengthen.

Wind switch on buoy 41008 last night off of SavanahLink
Farther south it sinks the better the conditions to strengthen huh...............................
RIGHT NOW WIND SHEAR FROM THE NORTH HITTING THIS INVEST BY MORNING THE WIND SHEAR WILL GOING DOWN
Quoting Skyepony:
The Carolina disturbance has gone from shrimp shaped blob to invest.. It's now 91L.. Winds are 20kts.. Off land & this far south it could strengthen.

Does look like it is wanting to on the vis loop.
Melbourne long range radar gets a good view.  
Quoting 518. superpete:

Morning to all. The current T wave approaching S.A. may end up being a rain maker for the islands.




The southern islands, not the northern.
NWS, Wilmington, NC..

maybe a 1-2 punch..head south and come back North..

.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO SLOWLY DEVELOP OFF THE SOUTHEAST U.S.
COAST INTO EARLY NEXT WEEK AND THIS WILL KEEP THE RISK OF SHOWERS
AND THUNDERSTORMS WITH HEAVY RAIN IN THE FORECAST THROUGH THE
WEEKEND. UPPER RIDGING WILL BUILD OVERHEAD NEXT WEEK BRINGING A
RETURN TO ABOVE NORMAL TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM SATURDAY...SHOWERS AND THUNDERSTORMS WERE DEVELOPING
AND INCREASING IN NUMBER ALONG AN OUTFLOW BOUNDARY SITUATED OFF THE
CAPE FEAR AND GRAND STRAND BEACHES THIS MORNING. SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO PIVOT ONTO THE
COAST IN THESE AREAS THROUGH 900 AM.

WEAK LOW PRESSURE WAS LOCATED JUST OFFSHORE OF THE SOUTH CAROLINA
COAST THIS MORNING. THIS AREA OF LOW PRESSURE IS EXPECTED TO REMAIN
NEARLY STATIONARY THROUGH THE PERIOD WITH LITTLE INTENSIFICATION
EXPECTED THROUGH TONIGHT.

HOWEVER...THE DEEP AND MOIST CIRCULATION AROUND THIS FEATURE COUPLED
WITH A NEARLY STATIONARY FRONT JUST TO OUR S AND E WILL PROVIDE AN
ENVIRONMENT CONDUCIVE FOR THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS AS MOIST AIR IS LIFTED UP AND OVER THE SHALLOW FRONT.
EVEN THOUGH WE WILL BE ON THE OTHER SIDE OF THE FRONT TODAY...THE
AIR MASS IS EVERY BIT AS MOIST AS THAT OF FRIDAY WITH PRECIPITABLE
WATER VALUES UP NEAR 2.25 INCHES. STORM MOTIONS WILL BE SIMILAR TO
FRIDAY...AROUND 5 KT. THE SYNOPTIC SETUP IS A LITTLE BIT DIFFERENT
IN THAT THE GREATEST PROBABILITY FOR HEAVY RAIN AND THE RESULTING
FLOOD RISK WILL BE ALONG AND NEAR THE COAST AS SHOWERS AND
THUNDERSTORMS WRAP CYCLONICALLY AROUND DEVELOPING LOW PRESSURE.
STILL...THE CIRCULATION IS BROAD ENOUGH TO INCLUDE LIKELY POPS FOR
THE ENTIRE FORECAST AREA WITH ABOUT CATEGORICAL FOR MOST OF THE
IMMEDIATE COAST. SOME OF THE HIGHER RESOLUTION MODELS ARE INDICATING
OFFSHORE CONVECTION WILL WRAP INTO THE NEAR SHORE WATERS AND MORE
COASTAL ENVIRONS TO INCLUDE THE BEACHES THIS MORNING.
531. wxmod


Dusty and dry :/
GOES East Rapid Scan starts this hour, and lasts until tomorrow.


91L centered visible loop
91L is very much embedded within an area of a high MSLP, so pressures will remain high in 91L even if it does become a tropical cyclone.
Quoting 528. CaribBoy:



The southern islands, not the northern.


You mean the Windwards.
A bi-blob. Grothar Alert 2B.



Quoting 519. Skyepony:

The Carolina disturbance has gone from shrimp shaped blob to invest.. It's now 91L.. Winds are 20kts.. Off land & this far south it could strengthen.




That's what good blobs do.
Looks like a little ventilation shaping up Groth!
Quoting 538. Grothar:

A bi-blob. Grothar Alert 2B.




Quoting 538. Grothar:

A bi-blob. Grothar Alert 2B.






Uhhhh A blob and blobette.
I just hope nothing happens to the Taco Johns in Tavares. It is the only one in Florida, and the manager is not spry.
Given increasingly more favorable conditions for development unfolding with lessening wind shear and warmer waters, I would not be surprised if Invest 91L becomes our first tropical cyclone of the 2014 Atlantic Hurricane Season. Looking like a textbook early season development underway.
Quoting 537. Grothar:



You mean the Windwards.


Yes............................ :-( (lol)
Quoting 543. cchsweatherman:

Given increasingly more favorable conditions for development unfolding with lessening wind shear and warmer waters, I would not be surprised if Invest 91L becomes our first tropical cyclone of the 2014 Atlantic Hurricane Season. Looking like a textbook early season development underway.


They expected a lot of storms to intensify last year, and they didn't. Past few years have been similar. I'll wait to see this year's emerging 'pattern', before getting interested.
546. 7544
Quoting 543. cchsweatherman:

Given increasingly more favorable conditions for development unfolding with lessening wind shear and warmer waters, I would not be surprised if Invest 91L becomes our first tropical cyclone of the 2014 Atlantic Hurricane Season. Looking like a textbook early season development underway.


is this the farest south it gets before it heads north tia
28th-30th. Warm, humid with scattered thunderstorms. A tropical storm threat along Southeast coast. Not bad.
Quoting 544. CaribBoy:



Yes............................ :-( (lol)


Caught that one, did ya?? :)
Blob 1 dropping southward fast. Looks like I am in for a wet weekend and who knows what else next week. Looks like heading straight for lower Central and upper South Florida east coast. Looking forward to heading out to the beach tomorrow and checking out the waves. Love walking the beach with large waves breaking and the wind blowing. Even a few rainy squalls are ok. Just amazed and awed by the power of the ocean when a tropical "something" is offshore.
Quoting 540. Abacosurf:

Looks like a little ventilation shaping up Groth!


Yessir. We're getting outflow.
91 AL disturbance will consolidate further South and the loop will be made nearer Canaveral than currently expected. That's my prediction and I'm sticking to it! ;Q
I wonder what the much-maligned GFS is saying about 91L.
554. beell
Some good "turning" at/near the surface just off the NC/SC border.
(static loop ending at 1447Z)


click for larger image
You can see the main low spinning up at the top (furthest north) of the radar loop.





All three crayons out for the NHC. Finally, the Atlantic has taken its sweet time in getting going.
Morning all. Intense storms yesterday. Nearly white-out conditions. It certainly was a slow drive to work. Luckily it came and went early in the day. Have a great day! Weekend!!



It's trying.



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

A weak low pressure system located just off the coast of South
Carolina is producing an area of disorganized showers and
thunderstorms. Environmental conditions are expected to remain
conducive for gradual development of this system while
it drifts southward during the next few days.
* Formation chance through 48 hours...medium...30 percent.
* Formation chance through 5 days...medium...50 percent.
558. beell
Quoting 534. nrtiwlnvragn:

GOES East Rapid Scan starts this hour, and lasts until tomorrow.


91L centered visible loop


Thanks, nrt!
12z NAM at 84 hours

Quoting 556. WIBadgerWeather:





All three crayons out for the NHC. Finally, the Atlantic has taken its sweet time in getting going.
As NC said the switch has been turned on oh, the switch has been turned on.
Looks neat on the earth wind map. Don't know how to post it correctly.
Good Morning Class!

Weather Conditions for:
Sunshine Summit, CA (SSSSD)
Elev: 3244 ft; Latitude: 33.344; Longitude: -116.732

Current time: Sat, 28 Jun 8:18 am (PDT)
Most Recent Observation: Sat, 28 Jun 8:10 am PDT (PDT)
Time Temp. Dew Relative Wind Wind Quality
Point Humidity Direction Speed Control
(PDT) (f) (f) (%) (mph)
28 Jun 8:10 am PDT 68 54 61 E 4G07 OK
I'm watching an interesting feature to the south of Invest 91L this morning. It appears to be a small but prominent mid/upper level low pushing towards Florida from the Bahamas. Will be interesting to see if this has any effect.
Minimum TS heading for btwn Ctrl Brvrd & S Ind Rv Cnty, then loops over land up & out ext Volusia, scraping E Orl metro to NE ATL waters. If neg form, then wet late Sun CFL. If pos form then windy and squally late Mon.
566. beell
91L Floater
567. 7544
Quoting 564. cchsweatherman:

I'm watching an interesting feature to the south of Invest 91L this morning. It appears to be a small but prominent mid/upper level low pushing towards Florida from the Bahamas. Will be interesting to see if this has any effect.



maybe thats what making it go south now then stall out there imo
The motion of 91L has been steadily to the southeast. I believe it will start making a little loop back west, but may not even get far enough south to affect central Florida much. I haven't seen any model yet bringing the system any further than the Florida-Georgia border.





569. beell
Perhaps something like this at the surface for now.

Quoting 547. Climate175:

28th-30th. Warm, humid with scattered thunderstorms. A tropical storm threat along Southeast coast. Not bad.


but wait..the Almanac is foolish according to some bloggers on here..got andrea last year and got this one..
Another Debby situation?
JeffMasters has created a new entry.
Quoting 570. ncstorm:



but wait..the Almanac is foolish according to some bloggers on here..got andrea last year and got this one..
Some bloggers have said it's pointless, it is predicting another threat for the Southeast around this same time next month, we will see.
how exciting...an invest off the east coast of florida
TODAY-TONIGHT...THE MODELS CONTINUE TO SHOW A WEAK SURFACE LOW
PRESSURE CENTER VICINITY OF SOUTH CAROLINA/GEORGIA COAST DROPPING
SOUTHEASTWARD TO THE WATERS 100-150 MILES OFFSHORE VOLUSIA COUNTY
TONIGHT. A WEAK HIGH PRESSURE CELL IN THE NORTHEAST GULF WILL
ALLOW FOR A LIGHT OFFSHORE FLOW THIS MORNING WHICH WILL HOLD OFF
THE SEA BREEZE UNTIL EARLY AFTERNOON...WHICH SHOULD CAUSE MAX
TEMPS TO REACH THE LOWER 90S AREAWIDE.

Area forecast discussion
National Weather Service Tallahassee Florida
957 am EDT Sat Jun 28 2014

Short term [tonight through monday]...

Deep layer ridging will prevail across our forecast area through the
period
...with above-average 500 mb heights. The GFS & European model (ecmwf)
forecast 850 mb temperatures to continue to be well-above average
over our area (generally 2 to 2.5 Standard deviations above
climo), which means hot daytime temperatures in the upper 90s to
around 100 deg. Fortunately there will be enough boundary layer
drying to limit heat index values below 105 deg, but it will still
be uncomfortable for most warm-blooded animals.
The 1000-700 mb
mean wind will be north to northwest near 10 kt, which (as we
observed on friday) will pin most of the northwest Florida sea breeze
front at the coast until late afternoon or early evening.
Additionally, the boundary layer drying will depress SBCAPE values
to less than 1000 j/kg, which is abnormally low for this time of year.
The suppressed sea breeze front and relatively poor thermodynamics
will keep pops at 20% or less.




Long term [monday night through saturday]...

The period begins with Gulf ridging shifting nwd to over southeast
region and remains in place until beginning to erode late tues or
early Wed as a nrn stream longwave trough moves ewd into east half
of conus and then deepens swd progressively weakening ridge.
At
surface, latest guidance shows that above deepening longwave
trough advances swd into Gulf Coast states.
This shifts high over
north/cntrl Gulf wwd while Georgia coastal low then shifts further east-southeast into
Atlc, rather then southwestward over land by tues. This would favor
intensification of low with NHC forecasting a 30% chance of tropical
development out thru 5 days.
Forecast confidence not high, as much
(rain,clouds/ temps)depends on development of trough aloft and
this low. European model (ecmwf) continues to amplify trough noticeably more than
GFS which would favor more active convection. Best scenario is
that on Wed, mid trough deepens east-southeast to Atlc coast and begins to
absorb low shifting it east-southeast towards Bahamas with no area tropical
development and steering flow returning to SW. Passing impulses
will enhance Gulf seabreeze yielding a wet pattern. By Fri,
longwave trough begins to lift newd with return to at or below
climo type weather.


Will go with 30-40% on Mon and 30-50% tues thru thurs, then 30% on
Fri. Period will be quite warm with highs in the mid to upper 90s
with a few spots approaching 100 degrees each day thru thurs. Highs
on Fri in the low to mid 90s. Lows generally in the low to mid 70s.




Looks like 91L will go out to sea.
000
FXUS62 KTBW 280804
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
404 AM EDT SAT JUN 28 2014

...ANOTHER HOT STORMY DAY EXPECTED IN WEST CENTRAL AND SOUTHWEST
FLORIDA...

.SHORT TERM (TODAY - TONIGHT)...
WARM AND WET PATTERN CONTINUES ACROSS WEST CENTRAL AND SOUTHWEST
FLORIDA TODAY. HIGH PRESSURE OVER THE GULF OF MEXICO AND LOW
PRESSURE OFF THE CAROLINA COAST ARE REINFORCING A DEEP LAYER
OF NORTHERLY FLOW ACROSS THE PENINSULA OF FLORIDA. THIS IS A
RELATIVELY RARE PATTERN...WHICH IS CREATING OPPRESSIVE TEMPERATURES
TO CLOSE OUT JUNE. HEAT INDEX VALUES BETWEEN 100 AND 105 DEGREES
CAN BE EXPECTED TODAY...STAYING HYDRATED IS KEY THIS WEEKEND.

BOTH THE MAV AND MET MOS GUIDANCE HAVE BEEN PERFORMING WITH A COLD
BIAS OVER THE LAST FEW DAYS. DUE TO THE RARITY OF THE SYNOPTIC
PATTERN...THE STATISTICAL GUIDANCE STRUGGLES WITH THESE WARMER THAN
NORMAL TEMPERATURES. SRQ AND FMY HAVE EACH SET DAILY RECORDS IN THE
LAST FEW DAYS WITH TEMPERATURES OF 97. WARMER GUIDANCE DOES NOT HINT
AT A SPECIFIC REPEAT OF RECORD HIGH TEMPERATURES SATURDAY...BUT
MID 90S SHOULD BE PRETTY WIDESPREAD ACROSS MUCH OF WEST CENTRAL
AND SOUTHWEST FLORIDA. THE LACK OF CONTRAST BETWEEN WATER AND AIR
TEMPERATURES IS PREVENTING THE COOLING FEELING THAT SEA BREEZES
WOULD NORMALLY PROVIDE. THE DELAYED NATURE OF THE SEA BREEZE OVER
THE LAST FEW DAYS ALSO CONTRIBUTED TO THE RECORD TEMPERATURES
ALONG THE SUNCOAST. NOT EXPECTING TOO MUCH DIFFERENCE TODAY...BUT
IT IS DIFFICULT TO PINPOINT IF ANY SPECIFIC DAILY RECORDS WILL BE
TIED OR BROKEN TODAY. FAVORED A WARM BLEND OF GUIDANCE FOR THE
FORECAST...WITH HEAVY INFLUENCE BY THE NAM-DNG5 AND WARM MEMBERS
OF THE GFS ENSEMBLE.

THE OTHER SIDE OF THE FORECAST EQUATION IS THE AFTERNOON AND EVENING
CONVECTION EXPECTED ACROSS THE AREA AGAIN TODAY. FORECAST WILL BE
WETTER THAN MOS GUIDANCE...MAINLY DUE TO PLENTIFUL MOISTURE AND THE
PRESENCE OF A LOW LEVEL JET ACROSS PORTIONS OF CENTRAL AND SOUTHWEST
FLORIDA. 00Z GFS SHOWS A 20-25KT 700 MB JET ACROSS PORTIONS OF
SOUTHWEST FLORIDA AND THE LAKE OKEECHOBEE AREA TODAY...ACTING AS A
POTENTIAL FOCUS FEATURE FOR STRONG THUNDERSTORMS. STRONG TO SEVERE
THUNDERSTORMS WITH HAIL AND STRONG WINDS CANNOT BE RULED OUT AGAIN
TODAY AS 500 MB TEMPERATURES REMAIN IN THE -8 DEG C NEIGHBORHOOD
AND 18Z MUCAPE VALUES ARE WELL ABOVE 2000 J/KG ACROSS THE AREA.
EXPECT CONVECTIVE INITIATION FUELED BY BOUNDARY
COLLISIONS...THOUGH THE LOW LEVEL JET OVER SW FLORIDA COULD ALLOW
ACTIVITY TO START EARLIER THERE.


The severe risk across Central and South Florida may be a bit higher today than the typical spotty severe cells that occur on a typical day here thanks to high instability combining with the presence of a LLJ. High instability is common here, but a LLJ is not this time of year, which will help to enhance the coverage of thunderstorms going severe. Also the hotter than normal temps this year will help enhance the risk with a bit high than usual surface instability.

It reached the mid to upper 90's yesterday including 97 at Sarasota and at my house, which was the hottest high temp I've seen in 2-3 years here. Not very often you see upper 90's in a county surrounded by water on the 3 sides along the gulf coast.





91L has a nice ULAC overhead now. Freshly updated. Curious if it can hold on to it.

Quote Post # 577
The severe risk across Central and South Florida may be a bit higher today than the typical spotty severe cells that occur on a typical day here thanks to high instability combining with the presence of a LLJ. High instability is common here, but a LLJ is not this time of year, which will help to enhance the coverage of thunderstorms going severe. Also the hotter than normal temps this year will help enhance the risk with a bit high than usual surface instability.

It reached the mid to upper 90's yesterday including 97 at Sarasota and at my house, which was the hottest high temp I've seen in 2-3 years here. Not very often you see upper 90's in a county surrounded by water on the 3 sides along the gulf coast.








Yesterday we got pounded in S.W. Florida. Here's a pic of one of the water spouts in Fort Myers.
repost
Meanwhile, across the isthmus.......is 96E, looking better than it's cousin 91L, trying to get going

12Z GFS doesnt think much of 91L............................................... ...............
Quoting 576. WIBadgerWeather:





Looks like 91L will go out to sea.
if it does go out to sea..the GEM model pegged that a few days ago,it never touches land
12Z NAM brings it real close to florida........................................... ....................
Quoting LargoFl:
12Z NAM brings it real close to florida........................................... ....................


That's about the same spot as the 00z Euro. Waiting to see the next Euro run.
heavy rain so far for the last two hours..

Storms just starting to form across South Fl.



Updated - up to 103 heat index.


Later this afternoon we should see some really strong storms. There's a lot of heat energy just waiting for the atmosphere to let go.

Slowly trying to wrap itself up a little. If the Low can stay over open water long enough, it could definitely develop into our first storm (at least a T.D.) of the season.
Looking very interesting for the S.E.

Euro showing a quicker spin up and landfall.



Quoting 576. WIBadgerWeather:





Looks like 91L will go out to sea.

wrong... it will hit florida and if it remains weak...the difflection will send it to the gulf. Those banking on north turn/ots need to see it form sooner...otherwise stronger low level ridge will send it ssw 2 - 3 days and keep doing so beyond that.
Quoting 593. Camille33:


wrong... it will hit florida and if it remains weak...the difflection will send it to the gulf. Those banking on north turn/ots need to see it form sooner...otherwise stronger low level ridge will send it ssw 2 - 3 days and keep doing so beyond that.

hwrf model maybe right stay tuned,it is not an outlier...you will see at 00z.