Developing Low -Heavy Rain/Gale Force Winds- Is invest 93L

[Blown Away]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
333 AM EDT FRI OCT 7 2011

.DISCUSSION...

...POTENTIAL FOR A HEAVY RAINFALL EVENT ALONG THE COAST LATE
TONIGHT AND CONTINUING OVER THE WEEKEND...

...HAZARDOUS MARINE CONDITIONS AND BEACH EROSION THROUGH THE WEEKEND...

SAT...POSSIBLE COASTAL RAIN EVENT ONGOING IN THE MORNING AS THE
GFS CONTINUES TO SHOW A LOW LEVEL WIND SURGE AND THE ASSOCIATED
MOISTURE CONVERGENCE BAND AROUND CANAVERAL AND SLIDING SLOWLY
SOUTH. WITH TROUGH ALOFT PROVIDING LARGE SCALE ASCENT AND AVERAGE
SURFACE TO 850 MB WINDS AROUND 25 KNOTS...THERE IS A POTENTIAL FOR
WIDESPREAD HEAVY RAINFALL ALONG THE COAST. MODEL AMOUNTS ARE
AROUND AN INCH BUT THESE KINDS OF CONVERGENCE BANDS OCCURRING OVER
STILL VERY WARM WATER CAN GENERATE MUCH HIGHER AMOUNTS. THE ONE
THING THAT MIGHT LIMIT AMOUNTS THOUGH IS THAT THE BAND IS SHOWN
DROPPING SLOWLY SOUTH...AND NOT STAYING QUASI STATIONARY. PLAN TO
KEEP THE PREVIOUS QPF AMOUNTS...ONE TO THREE INCHES ALONG THE
COAST...AND CONSIDERABLY LESSER AMOUNTS INLAND.

SUN-EARLY NEXT WEEK...THERE IS STILL DIFFERING SOLUTIONS FROM THE
MODELS WITH RESPECT TO DEVELOPMENT OF SUBTROPICAL LOW ALONG
STALLED OUT FRONTAL BOUNDARY TO OUR SOUTH. IT LOOKS LIKE ON THE
00Z RUN...THE GFS IS SUFFERING SOME CONVECTIVE FEEDBACK PROBLEMS
AND FORMS A LOW OVER THE BAHAMAS ON SUNDAY...THEN LIFTS IT NORTH
TO NORTHWEST JUST OFFSHORE THE FLORIDA EAST COAST. THE ECMWF
CONTINUES WITH A LOW IN THE GULF OF MEXICO. THE NAM IS IN THE
MIDDLE AND CLOSER TO THE HPC MANUAL PROGS SHOWING A LOW PULLING
NORTH JUST OFFSHORE THE WEST COAST.

THINK THAT A HEAVY RAIN BAND ALONG THE SOUTHEAST FLORIDA COAST
WILL START TO LIFT BACK NORTH ON SUNDAY AS THE LOW FORMS IN THE
FLORIDA STRAITS. LOW LEVEL SHEAR WOULD START TO INCREASE SO IN
ADDITION TO HEAVY RAIN...A THREAT FOR TORNADOES MAY DEVELOP
ESPECIALLY ALONG THE COAST. EXPECT THAT THE HEAVIEST RAIN WOULD BE
NEAR THE EAST COAST BUT IF THE LOW TRACKS NEAR THE WEST
COAST AS PROGGED...MUCH OF THE AREA WILL HAVE A CHANCE FOR HEAVY
AMOUNTS. WILL NOT DIFFER FROM HYDROLOGIC OUTLOOK" ISSUED YESTERDAY
WHICH INDICATES STORMS TOTAL AMOUNTS ON THE COAST OF 3 TO 6 INCHES
AND 1 TO 3 INCHES INLAND. AS NOTED ABOVE...THESE EARLY SEASON
FRONTS CAN PRODUCE MUCH HIGHER AMOUNTS. A FLOOD WATCH WILL NEED TO
BE CONSIDERED DURING THE NEXT FORECAST PACKAGE.

THE PROLONGED PERIOD OF STRONG ONSHORE WINDS WILL RESULT IN VERY
HAZARDOUS SURF. BEACH EROSION IS EXPECTED TO BECOME SIGNIFICANT.

MID-LATE NEXT WEEK...THE MODELS EVENTUALLY COME TOGETHER SHOWING
THE LOW LIFTING NORTH OF THE AREA AS A TROUGH DIGS OVER THE
EASTERN PART OF THE COUNTRY. MOISTURE WILL REMAIN HIGHER THAN
NORMAL SO RAIN CHANCES WILL CONTINUE IN THE FORECAST. TEMPS SHOULD
BE WARMER THAN NORMAL WITH HIGHS REACHING THE UPPER 80S AND
HUMIDITY RETURNING TO SUMMER LIKE LEVELS.

[AdamFirst]

Florida Subtropical Floodpocalypse 2011 has begun early here

FLOOD ADVISORY
NATIONAL WEATHER SERVICE MELBOURNE FL
729 AM EDT FRI OCT 7 2011

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
EASTERN ST. LUCIE COUNTY IN FLORIDA...
THIS INCLUDES THE CITIES OF...WALTON...FORT PIERCE INLET...WHITE
CITY...SAINT LUCIE NUCLEAR PLANT...PORT SAINT LUCIE...INDRIO...FORT
PIERCE...

* UNTIL 930 AM EDT.

* AT 726 AM EDT...WEATHER SERVICE DOPPLER RADAR ESTIMATED THAT
RAINFALL AMOUNTS WERE BETWEEN THREE AND FOUR INCHES AROUND FORT
PIERCE AND PORT SAINT LUCIE. ADDITIONAL RAINFALL AMOUNTS OF ONE TO
TWO INCHES ARE POSSIBLE AS ADDITIONAL SHOWERS FROM THE ATLANTIC
COASTAL WATERS MOVE ASHORE.

Convergence has set up right on top of us. The rain started around 11 PM last night and has continued since.

[Blown Away]

I might change the title to "Florida Subtropical Floodpocalypse," very funny!!

[SouthFLTropics]

5+ inches overnight in both of my rain gauges in Fort Pierce as of 8:00AM this morning. I emptied them out and now we will see what we can stack up the next 24 hours. I'm guessing another 5+ possibly.

SFT

[jdray]

Hopefully it doesn't end up like another Fay like drenching. I hated that storm. Way too much rain for most of Florida. My area got almost 20" of rain from her.

[WYNweather]

This reminds me of the No name Strom in 93 when i lived in ST. Pete. Does anyone recall how this storm set up?http://www2.sptimes.com/weather/SW.3.html

[tolakram]

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

Only potential wind shift I see is south of Cuba. Will be interesting to see where this develops.

[wxman57]

Vorticity associated with the same wave that spawned Philippe has passed Haiti and is heading for western Cuba. It appears that a non-tropical low will develop in the vicinity of the FL Straits to the SW Bahamas on Sunday. Prior to then, expect increasing squalls well to the north of the developing low across the FL peninsula. I suspect the NHC will start mentioning the potential development later today as a possible subtropical storm with a 20-30% chance of development within 48 hours (though I think it's more like 90% or more that a low will develop in the next 72 hrs).

The low will be blocked to the north initially, but should move slowly northward just off the east coast of FL on Monday, reaching GA and/or SC by Tuesday morning. It could transition to a TS on Monday. Chances of it becoming a strong TS or H don't look good. Probably not much wind over land. Rain across Florida will probably diminish on Sunday afternoon as the low consolidates and convection moves closer to the low center. Could be some significant rain for the Carolinas on Tue/Wed as the low moves slowly northward along the coast.

[AdamFirst]

Rain across Florida will probably diminish on Sunday afternoon as the low consolidates and convection moves closer to the low center.

Would the coast still be impacted by the rains if the low parallels the coast?

Flood advisory has been continued here.

FLOOD ADVISORY
NATIONAL WEATHER SERVICE MELBOURNE FL
926 AM EDT FRI OCT 7 2011

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
EASTERN ST. LUCIE COUNTY IN FLORIDA...
THIS INCLUDES THE AREAS OF...WALTON...FORT PIERCE INLET...WHITE
CITY...SAINT LUCIE NUCLEAR PLANT...PORT SAINT
LUCIE...INDRIO...AND FORT PIERCE...

* UNTIL 1130 AM EDT.

* AT 924 AM EDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT UP TO
3 INCHES OF RAIN HAD FALLEN IN THE PAST THREE HOURS WITH UP TO 5
INCHES OF RAIN SINCE MIDNIGHT. MORE RAIN IS EXPECTED OVER THE NEXT
COUPLE OF HOURS.

[SFLcane]

Tight low-level pressure gradient should make for rather windy weekend across SFL but i think the main issue with be the Heavy rainfall with potential flooding in some areas.

[wxman57]

Would the coast still be impacted by the rains if the low parallels the coast?

Depends on how close to the coast it passes. It may have most convection east of the center by Monday.

[brunota2003]

coastal NC doesn't need any more rain! Much more, and they might disappear into the sea!

[KUEFC]

Am really confused here, Jeff Masters is talking about the low pressure system forming tomorrow, but yet everything and everyone else is saying Sunday? can some explain what Jeff Masters is seeing?

[wxman57]

Am really confused here, Jeff Masters is talking about the low pressure system forming tomorrow, but yet everything and everyone else is saying Sunday? can some explain what Jeff Masters is seeing?

No need to be confused. The pressures will start lowering from the NW Caribbean to the Bahamas tomorrow. One could say that the low begins forming tomorrow. But the real development/deepening would be on Sunday/Monday.

[AJC3]

Am really confused here, Jeff Masters is talking about the low pressure system forming tomorrow, but yet everything and everyone else is saying Sunday? can some explain what Jeff Masters is seeing?

It's not going to be developed by Saturday. It'll take at least a couple of days to spin up, and even then it's liable to be a sheared, sloppy baroclinic low.

[HurricaneBelle]

Am really confused here, Jeff Masters is talking about the low pressure system forming tomorrow, but yet everything and everyone else is saying Sunday? can some explain what Jeff Masters is seeing?

No need to be confused. The pressures will start lowering from the NW Caribbean to the Bahamas tomorrow. One could say that the low begins forming tomorrow. But the real development/deepening would be on Sunday/Monday.

Any thoughts on why TBW is hugging the Euro and insistent on development on the west side of Florida? I presume they believe the low will form further west.

[KUEFC]

Thanks again AJC3 and wxman57 just intresting trying to follow it all,

[AJC3]

Am really confused here, Jeff Masters is talking about the low pressure system forming tomorrow, but yet everything and everyone else is saying Sunday? can some explain what Jeff Masters is seeing?

No need to be confused. The pressures will start lowering from the NW Caribbean to the Bahamas tomorrow. One could say that the low begins forming tomorrow. But the real development/deepening would be on Sunday/Monday.

Any thoughts on why TBW is hugging the Euro and insistent on development on the west side of Florida? I presume they believe the low will form further west.

It's not just the Euro, the majority of guidance has suggested that the low center will ride up along or just west of the west coast. That's the solution I favor as well. The GFS has been insistent on the low center moving near or east of the east coast. Again, in all likelihood it's going to be a sloppy BI/BE (baroclincally initiated-enhanced) type system.

[LarryWx]

Last 8 GFS runs for potential early week SE US tropical storm: pretty consistent

18Z Wed: Brunswick 1000 mb 10/11
00Z Thu: St. Augustine 1005 mb 10/11
06Z Thu: Charleston 1003 mb 10/11
12Z Thu: Brunswick 1003 mb 10/11
18Z Thu: Brunswick 1003 mb late 10/10
00Z Fri: Wilmington 1008 mb 10/12 (appears to be extratropical at landfall)
06Z Fri: Beaufort 1003 mb 10/11
12Z Fri Midway 1005 mb 10/10

Although no other major model has yet to show a definitive SE coast tropical storm landfall (as far as I know), the GFS has been pretty consistent/insistent on this over a fairly tight corridor (St. Augustine to Charleston). Also, the GGEM is now getting close to this kind of solution after previously being in the Gulf. The Euro is still holding tough with its Gulf solutions. However, even it is showing subtle signs of moving further east. We'll see. The UKMET is still going with the Gulf (as of the 12Z Fri run), but it often is a west outlier. Fun times for some of us for a change!

[N2Storms]

[quote="LarryWx"][u]Last 8 GFS runs for potential early week SE US tropical storm: pretty consistent[/u]

18Z Wed: Brunswick 1000 mb 10/11
00Z Thu: St. Augustine 1005 mb 10/11
06Z Thu: Charleston 1003 mb 10/11
12Z Thu: Brunswick 1003 mb 10/11
18Z Thu: Brunswick 1003 mb late 10/10
00Z Fri: Wilmington 1008 mb 10/12 (appears to be extratropical at landfall)
06Z Fri: Beaufort 1003 mb 10/11
12Z Fri Midway 1005 mb 10/10



Although no other major model has yet to show a definitive SE coast tropical storm landfall (as far as I know), the GFS has been pretty consistent/insistent on this over a fairly tight corridor (St. Augustine to Charleston). Also, the GGEM is now getting close to this kind of solution after previously being in the Gulf. The Euro is still holding tough with its Gulf solutions. However, even it is showing subtle signs of moving further east. We'll see. The UKMET is still going with the Gulf (as of the 12Z Fri run), but it often is a west outlier. Fun times for some of us for a change![/quote]



We need some rain in the worst way but it doesn't look like we're going to get much of anything here in PC regardless of where the Low eventually forms and ends up heading. Very disappointing but not unexpected...