Development off SE Coast (Invest 98L)

[Ivanhater]

The best shot imo for development will be off the SE Coast...model guidance likes it.

12z GFS

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00z Euro

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[Ivanhater]

HPC morning update:

OF PARTICULAR NOTE IS A
SMALL BUT POTENTIALLY SIGNIFICANT AREA OF LOW PRESSURE WHICH THE
MODELS ARE DEVELOPING ALONG A STATIONARY FRONT DRAPED ACROSS THE
SOUTHEAST COAST SUNDAY THROUGH TUESDAY. DESPITE RELATIVELY WEAK
MSLP VALUES...ITS SLOW MOVEMENT WITHIN AN ANOMALOUSLY MOIST
ENVIRONMENT SUPPORTS THE POSSIBILITY...
ALBEIT WITH LIMITED PREDICTABILITY...OF HEAVY RAINFALL DEVELOPING
ALONG PORTIONS OF THE SOUTHEAST COAST DURING THE SECOND HALF OF
THE PERIOD. WILL NEED TO MONITOR FOR FURTHER MODEL CONTINUITY
AND/OR POTENTIALLY STRONGER SCENARIOS FOR INCREASING CONFIDENCE.

[GCANE]

Looks like it will have a good opportunity to sit and brew for a while.

12Z Globals are showing this stalled for a good 3 days over the weekend with good UL support over it.

[northjaxpro]

Yes, the models are latching onto the potential of a Low pressure area to form off the GA/SC coast next week.

Here are some extended 7 day outlooks from NWS WFOs along the SE Atlantic coast discussing the possible development next week.

NWS Jax, FL:

LONG TERM...UPPER HIGH IS PROGGED TO WEAKEN OVER THE LOCAL AREA
AND REBUILD WELL TO THE NW OVER THE CENTRAL PLAINS AND MS VALLEY.
AS A RESULT...ATLC SEABOARD TROF WILL HAVE MORE OF AN INFLUENCE
ACROSS THE AREA WITH BETTER CHANCES OF PRECIP AN TEMPS CLOSER TO
NORMAL. BOTH THE GFS AND ECMWF HAVE BEEN TOYING WITH THE IDEA OF
SFC LOW DEVELOPMENT OFF THE SC COAST BY LATE IN THE WEEKEND. THIS
WILL HAVE A MARKED IMPACT ON OUR WX. IF THE FEATURE REMAINS MORE
OF AN OPEN WAVE...GOOD CHANCES OF PRECIP WILL LIKELY CONTINUE. IF
THE FEATURE DEVELOPS NE OF THE AREA...WE MAY SEE SOMEWHAT DRIER
AIR WRAP AROUND FROM THE N AND NW. IT DOES APPEAR THAT A LOW WILL
DEVELOP IN THAT AREA...BUT THE STRENGTH OF THE LOW REMAINS IN
QUESTION.


NWS Charleston, SC

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
UPPER LEVEL TROUGHING ALONG WITH A STALLED SURFACE FRONT OVER THE
REGION...IS EXPECTED TO RESULT IN A UNSETTLED PERIOD OF WEATHER
ACROSS THE SOUTHEAST STATES THROUGH THE LONG TERM PERIODS. THE
LATEST MODEL SOLUTIONS ARE NOW BEGINNING TO COME INTO BETTER
AGREEMENT DEVELOPING AN AREA OF LOW PRESSURE /POTENTIAL TROPICAL
SYSTEM/ OFF THE SOUTH CAROLINA AND GEORGIA COAST LATE IN THE WEEKEND
INTO EARLY NEXT WEEK. SEVERAL MODELS HAVE SHOWN SOME INDICATION OF
THIS FOR THE PAST DAY OR TWO...BUT THIS IS THE FIRST MODEL CYCLE IN
WHICH ALL THE GLOBAL MODELS HAVE LATCHED ONTO SOME LOW PRESSURE
DEVELOPMENT OFF THE SOUTHEAST COAST. QUITE A BIT OF UNCERTAINTY
OBVIOUSLY REMAINS WITH THE STRENGTH...INTENSITY...AND EVENTUAL TRACK
OF ANY SYSTEM THAT MAY DEVELOP OFF THE COAST LATE THIS WEEKEND INTO
EARLY NEXT WEEK...BUT IT WILL CERTAINLY BE SOMETHING TO KEEP A CLOSE
EYE ON OVER THE NEXT WEEK.


NWS Wilmington, NC

LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...LONG TERM PATTERN OF A MASSIVE RIDGE IN THE
CENTRAL PLAINS AND CUTOFF LOW PRESSURE MEANDERING OFF THE
SOUTHEAST COAST REMAINS INTACT. THE DEVIL IS IN THE DETAILS OF
COURSE AS MODELS HAVE NUDGED TOWARD BETTER AGREEMENT OF AN AREA OF
LOW PRESSURE DEVELOPING ALONG THE COAST LATE IN THE WEEKEND AROUND
THE SAVANNAH AREA. THIS ALONG A FRONT THAT MOVES ACROSS OUR AREA
THURSDAY

[northjaxpro]

The models have now backed off somewhat on the possible surface Low pressure development off the SE U.S. Coast for the Sunday-Wednesday time frame for this upcoming week.

Just reading through the NWS WFOs discussions from JAX, Charleston, SC, and Wilmington, NC late today, they state now the models are not as robust in spinning up one. Most models are now depicting a frontal wave to develop on the tail end of the boundary which will stall in the SW Atlantic by late this weekend.

This will still be something to watch going into the weekend as hybrid tropical systems are known to spin up in this region.

[Hurricaneman]

It could still happen, but I wouldnt count on it with model support waning

[flwxwatcher]

Latest HPC discussion about the SE coast and development chances.

A STATIONARY FRONT DRAPED ACROSS THE SOUTHEAST
COAST SUNDAY THROUGH TUESDAY IS EXPECTED TO SUPPORT POSSIBLY HEAVY
RAINFALL DEVELOPING ALONG PORTIONS OF THE SOUTHEAST FROM THIS
WEEKEND INTO EARLY NEXT WEEK WITHIN AN ANOMALOUSLY MOIST
ENVIRONMENT. THE MODELS HAVE GENERALLY BACKED OFF THE SFC LOW
DEVELOPMENT BUT THE INGREDIENTS REMAIN IN PLACE.

[hurricanetrack]

Good, for those who want to see some quality hurricanes out there this season, and not hit land of course, then frontal development NOT happening is a good sign. Let's wait until about August 20 and then get some real deep tropical development not that frontal mess.

[northjaxpro]

15z HPC surface analysis depicts 1011 mb frontal low in the vicinity of Savannah, GA.

http://www.hpc.ncep.noaa.gov/sfc/90fwbg.gif


The boundary is already beginning the process of stalling out off the SE US coast.

The ingredients are there on the tail end of this boundary for the possibility of something developing this weekend. Keep monitoring!

[LarryWx]

Folks,
Both the 6z gfs and 6z nam are hinting at something tropical forming off of the SE coast by Monday. With anomalously high sfc pressures (1025 mb) for July progged to persist to the N and NE of this area through the late weekend into early next week, this area will probably need to be monitored for the chance of a spinup that could subsequently threaten the SE coast around Tuesday. With this being July, this would be a pretty rare event (homegrown tropical cyclone that subsequently moves to the SE coast), but it has occurred a handfull of times over the last 100 years in July. So, although the odds are against it, it wouldn't at all be shocking considering the anomalously high sfc pressures to the NE.

[BigA]

Vorticity on the wax east of the North Florida Coast. I think I see some spin on the visible and radar loops



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[floridasun78]

their area moving off se coast

[northjaxpro]

Model runs still hinting at a possible surface Low pressure forming on the stalled frontal boundary this weekend, but the focus for development has now shifted farther south to off the FL East Coast or near the Bahamas by Sunday.


An excerpt from the NWS WFO Charleston, SC forecast discussion this afternoon:

THE DEVELOPMENT OF A COASTAL LOW OR WEAK TROPICAL WAVE OFF THE
FLORIDA COAST SUNDAY NIGHT INTO MONDAY REMAINS IN QUESTION. THE
00Z NAM SOLUTIONS DEPICTS A MORE WELL DEFINED LOW...WHILE THE GFS
AND ECMWF SUGGEST THE SYSTEM WILL BE MORE OF AN OPEN WAVE THAT
DISSIPATES TO THE SOUTH/SOUTHEAST BY MIDDAY MONDAY. WILL ONCE
AGAIN LEAN TOWARD THESE MORE SUBTLE SOLUTIONS...HINTING AT THE
OFFSHORE WAVE BY INCREASING POPS OVER THE WATERS AND COASTAL
COUNTIES SUNDAY NIGHT.


NWS WFO Jacksonville, FL late this afternoon

12Z GFS DEVELOPS A SURFACE LOW OFF THE FLORIDA EAST
COAST ALONG FRONTAL BOUNDARY ON SATURDAY. MODELS HAVE BEEN
INCONSISTENTLY HINTING AT THIS FOR DAYS SO WILL HAVE TO MONITOR
ANY SURFACE LOW DEVELOPMENT.


NWS WFO Melbourne, FL late this afternoon

SAT-MON...STRONG HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC
COAST SATURDAY AND BRING EASTERLY (ONSHORE) FLOW THROUGH EARLY
NEXT WEEK. WEAK FRONTAL BOUNDARY WILL DRIFT SOUTH DOWN THE
PENINSULA THROUGH THE WEEKEND AND DISSIPATE OVER SOUTH FLORIDA
BY MONDAY MORNING. THE MAIN FORECAST FEATURE WILL BE A LOW
PRESSURE SYSTEM WHICH MODELS DEVELOP BY SUNDAY. MODELS DISAGREE ON
THE POSITION OF THE WEAK LOW..CURRENTLY PLACING IT ANYWHERE FROM
WELL OFF THE SOUTHEAST U.S. COAST TO OVER THE BAHAMAS. WILL KEEP
AN EYE ON THIS FEATURE FOR INCREASED MOISTURE AND HIGHER RAIN
CHANCES SUNDAY AND INTO NEXT WEEK.

[flwxwatcher]

An excerpt from the NWS WFO Charleston, SC forecast discussion this afternoon:

THE DEVELOPMENT OF A COASTAL LOW OR WEAK TROPICAL WAVE OFF THE
FLORIDA COAST SUNDAY NIGHT INTO MONDAY REMAINS IN QUESTION. THE
00Z NAM SOLUTIONS DEPICTS A MORE WELL DEFINED LOW...WHILE THE GFS
AND ECMWF SUGGEST THE SYSTEM WILL BE MORE OF AN OPEN WAVE THAT
DISSIPATES TO THE SOUTH/SOUTHEAST BY MIDDAY MONDAY. WILL ONCE
AGAIN LEAN TOWARD THESE MORE SUBTLE SOLUTIONS...HINTING AT THE
OFFSHORE WAVE BY INCREASING POPS OVER THE WATERS AND COASTAL
COUNTIES SUNDAY NIGHT.


NWS WFO Jacksonville, FL late this afternoon

12Z GFS DEVELOPS A SURFACE LOW OFF THE FLORIDA EAST
COAST ALONG FRONTAL BOUNDARY ON SATURDAY. MODELS HAVE BEEN
INCONSISTENTLY HINTING AT THIS FOR DAYS SO WILL HAVE TO MONITOR
ANY SURFACE LOW DEVELOPMENT.

Yes, you can see the 12Z GFS having a weak area of low pressure off the Florida East Coast.


http://mag.ncep.noaa.gov/NCOMAGWEB/appc ... mageSize=M

[northjaxpro]

Also, I edited the previous post to include the WFO Melbourne forecast discussion late this afternoon.

[LarryWx]

A weak sfc low pressure appears to have formed offshore the N FL and GA coasts by ~100 miles and is nearly stationary with solid convection in a pretty tight area. This is the area to monitor just in case. It does appear that it MAY be slowly trying to organize.

[northjaxpro]

A weak sfc low pressure appears to have formed offshore the N FL and GA coasts by ~100 miles and is nearly stationary with solid convection in a pretty tight area. This is the area to monitor just in case. It does appear that it MAY be slowly trying to organize.

Yes, Larry you are correct. HPC 9z surface analysis depicted a 1013 mb Low pressure area about 100 miles east of Jacksonville. This is what the models have been hinting at for development along the stalled frontal boundary.

The surface Low is stationary currently and is sitting right over the warm Gulf stream current. It appears looking at IR satellite and radar imagery as of 6:30 a.m. EDT that convection is building and the Low Pressure area looks to be becoming better defined. Definitely something to watch over the next few days!

[LarryWx]

There appears to be a good bit of NW shear, which would need to be overcome in order to allow more than only a fairly small level of development. I think the first vis. will show a somewhat sheared mess with most of convection to the E and SE of the LLC.

[ronjon]

Correct Larry - NW shear looks to be about 20-30 kts. That's going to have to relax plus it'll have to diconnect from the frontal boundary to get going toward a tropical depression. Still, it's in a favorable location and its that time of year. Not sure about future movement as models have been inconsistent - latest GFS wants to take it at least partially W-SW over the FL peninsula and then eventually back NE.

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

[northjaxpro]

Yep, Larry you are probably right. Even on IR imagery, you can see the the low level swirl with the convection displaced just east and southeast of the circulation just off the SE GA coast.

But, as time progresses, this will be interesting to monitor. There is some westerly/northwesterly shear, but other ingredients are still there for the system to possibly survive and become a tropical entity these next few days.