Unusual Cold Front/Development East Coast?

[SouthFloridawx]

000
FXUS62 KMFL 080735
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
335 AM EDT TUE AUG 8 2006

.DISCUSSION...WATER VAPOR IMAGERY SHOWS THE UPPER LOW MOVING INTO
THE BAHAMAS EARLY THIS MORNING. GOES SOUNDER IMAGERY SHOWS MUCH
DRIER AIR MOVING INTO SOUTH FL AHEAD OF THIS FEATURE...AND
CONFIRMED BY GPS MET DATA WHICH SHOWS PWATS AT FLL AND MIA DOWN TO
THE 1.5-1.7 INCH RANGE AND FALLING. SO WITH A DRY ATMOSPHERE FOR
THIS TIME OF THE YEAR AND SUBSIDENCE WITH THE APPROACH OF THE
UPPER LOW...AM EXPECTING NOTHING MORE THAN ISOLATED SHRA/TSRA
ACROSS SOUTH FL TODAY. SO HAVE CONTINUED WITH 20 POPS EVERYWHERE
TODAY.

TONIGHT WILL SEE A MARKED TRANSITION IN AIRMASS ACROSS SOUTH
FLORIDA...AS MOISTURE SURGES INTO THE AREA FROM THE SOUTHEAST. GFS
FCST SOUNDINGS SHOW PWATS RISING ABOVE 2 INCHES ACROSS THE AREA
OVERNIGHT. THIS MOIST SURGE WILL BE BROUGHT ON BY TWO
FACTORS...ONE BEING THE UPPER LOW MOVING ACROSS THE AREA AND INTO
THE GULF WITH SOUTH FL BECOMING POSITIONED ON ITS MOIST/EAST SIDE...AND
THE OTHER BEING THE PASSAGE OF A TROPICAL WAVE...WHICH IS NOW
ALIGNED ACROSS THE SE BAHAMAS. THE NORTHERN EXTENT OF THIS WAVE
WILL LIKELY CROSS THE AREA AT AROUND MIDNIGHT...AND THIS IS WHEN
SCATTERED THUNDERSTORMS SHOULD BEGIN TO AFFECT THE SOUTHEAST
FLORIDA COAST. HAVE INCREASED POPS A BIT ACROSS THE SE
COAST...EXPOSED TO THE SE FLOW. HOWEVER...LAND COOLING AFFECTS ARE
EXPECTED TO KEEP GULF COASTAL AND INTERIOR AREAS DRY
OVERNIGHT...SO KEPT MINIMAL POPS THERE. COLDEST TEMPS ALOFT
ASSOCIATED WITH THE UPPER LOW WILL PASS ACROSS THE AREA AHEAD OF
THE WAVE AXIS...BUT STILL THE INTERACTION WITH THE UPPER COLD CORE
LOW AND THE TROPICAL WAVE COULD RESULT IN "LOUD" THUNDERSTORMS
OVERNIGHT.

NORTHERN EXTENT OF TROPICAL WAVE AND ITS DEEP MOISTURE WILL
CONTINUE TO AFFECT SOUTH FL WEDNESDAY...SO INHERITED LIKELY POPS
STILL LOOK GOOD EVERYWHERE. ABUNDANT CLOUD COVER ALONG WITH
WARMING MID LEVEL TEMPS SHOULD KEEP STORMS OF THE ORDINARY VARIETY
ON WEDNESDAY...UNLESS THE UPPER LOW STAYS CLOSER TO THE AREA WHICH
IS NOT EXPECTED AT THIS TIME.

DEEPEST MOISTURE GETS PULLED NORTH OF THE AREA FOR THE LATTER PART
OF THE WEEK AND THROUGH THE UPCOMING WEEKEND. GFS SHOWS VERY DRY
AIR ALIGNED ALONG 24 NORTH LATITUDE...WITH PWATS LESS THAN 1.5
INCHES...RATHER REMARKABLE FOR AUGUST. SFC RIDGE AXIS WILL BE
ALIGNED ACROSS SOUTH FL LATE WEEK. FOLLOWED GFS MOS POPS CLOSELY
THU-SUN WITH MOSTLY SLIGHT CHANCE POPS AT THE COAST AND CHANCE
POPS INTERIOR.

GFS SHOWS A SHORTWAVE DIVING ACROSS THE EASTERN U.S. OVER THE
WEEKEND...AND SENDS A BACK DOOR TYPE COLD FRONT ACROSS THE
CAROLINAS AND EVEN INTO THE WESTERN ATLANTIC JUST OFF THE EAST
COAST OF FLORIDA BY SUNDAY NIGHT AND MONDAY. PRETTY AMAZING FOR
AUGUST. TROPICS ARE LOOKING QUIET AS WELL.

May want to watch for some development from this cold front. This should weaken the ridge and allow any disturbances that we may/could/might a way north through.

If the front stalls out off the East Coast of Florida and the Shortwave pulls out, ridge building in it is quite possible something could come into florida or up the east coast.

[SouthFloridawx]

GFS showing possible low pressure forming off the coast and going out to sea.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... el_s.shtml

[mike815]

yup i could see that happening continued quiet tropics and perhaps somethinf forming off the front but yea right out to sea

[SouthFloridawx]

So far it is only Cold Core but, we'll keep watching the model runs and see.

[EDR1222]

Interestingly, in 04 there was an unseasonably strong cold front that came through as many will remember, allowing Charley to be picked up moving SW to NE across FL. Unusual event for mid August.

[SouthFloridawx]

[SouthFloridawx]

[mike815]

those are some interesting runs.

[SouthFloridawx]

[SouthFloridawx]

Willjnewton, I have been mentioning this possibility of East Coast development next week in this thread. Feel free to comment as much as you like.

[ThunderMate]

What are the models doing with this feature today?

[SouthFloridawx]

GFS showing a feature with some vorticity off the East Coast.

Not sure if it is warm or cold core cause the cyclone phase page hasn't really updated very much since yesterday.



CMC showing some vorticity off the coast in the bahamas.
Obviously nothing organized.


NOGAPS also showing some vorticity left over after the cold front moves out.

[SouthFloridawx]

One thing I would worry about this front is that the models want to push it out very quickly and any energy left behind could be blocked from leaving with the trough as:

Models building high pressure as fast moving trough comes through.

Blocking feature could block any energy left behind and push it back to the west.

Gotta watch this feature and any front that dips this far south in the Summer time.





http://bricker.met.psu.edu/~arnottj/cgi ... hour=120hr

[SouthFloridawx]

NWS MIA shows that my thinking on this situation is pretty sound.


000
FXUS62 KMFL 100758
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
358 AM EDT THU AUG 10 2006



GFS CONTINUES TO SHOW A NEARLY STATIONARY FRONTAL BOUNDARY
ALIGNED FROM THE CAROLINAS INTO THE WESTERN ATLANTIC GETTING A
PUSH SOUTH EARLY NEXT WEEK...TO BECOME POSITIONED OVER THE
ATLANTIC WATERS JUST TO OUR EAST BY TUE/WED...WITH TAIL END
POSSIBLY EVEN OVER THE PENINSULA. THIS MODEL SHOWS THE TAIL END
WASHING OUT AND A LOW DEVELOPING NEAR 29N/68W THEN MOVING
NORTHEAST AWAY FROM THE AREA IN RESPONSE TO A TROUGH. THIS IS FAR
DIFFERENT THAN ITS PREVIOUS RUN WHICH DEVELOPED A LOW JUST OFF THE
EAST CENTRAL FL COAST AND TOOK IT ACROSS THE PENINSULA NEXT WED.
THE ECMWF ON THE OTHER HAND IS DEVELOPING A LOW ALONG THE BOUNDARY
JUST OFF THE SOUTH CAROLINA COAST AND MOVES IT SW ACROSS NORTH
FLORIDA ON TUESDAY. SO MODELS ARE ALL OVER THE PLACE AND
INCONSISTENT...SO THE BEST OPTION IS TO JUST TREND POPS UP TOWARDS
CLIMO NEXT WEEK. SHOULD THE BOUNDARY MAKE IT AS FAR SOUTH AS THE
GFS SHOWS...GIVEN THE TIME OF YEAR IT WILL NEED TO BE WATCHED FOR
ANY LOWS WHICH TRY TO DEVELOP UNDERNEATH A BUILDING RIDGE TO OUR
NORTH.

[Stormavoider]

Is this a surface low trying to form off of the southern NC coast ?

http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=33&lon=-75&info=vis&zoom=1&width=2800&height=2000&type=Animation&numframes=12&palette=ir.pal

[Stormavoider]

The pressure is trying to cooperate.

http://www.ndbc.noaa.gov/show_plot.php?station=41013&meas=pres&uom=E

[SouthFloridawx]

[Weatherfreak14]

This is very interesting indeed.

[SouthFloridawx]

[Coredesat]

NOGAPS also develops something a little to the east of this at around the same time:

http://moe.met.fsu.edu/cyclonephase/ngp ... 1.zoom.png