Global model runs discussion

[xironman]

for a supposedly La Nina year, the cmc develops 4 storms in the EPAC within the next 10 days. Shouldn't the EPAC be already inactive this time around in a La Nina year?

Don't take the CMC (Constantly Makes Cyclones) cyclogenesis verbatim, the HPC long range discussion yesterday provides a good example

OVERALL...THE 00 UTC ECMWF/CANADIAN/UKMET AND TRENDS FROM THE
LATEST 12 UTC ECMWF SEEM IN GOOD AGREEMENT WITHIN THE ENSEMBLE
SPREAD FOR THESE SCENARIOS AND PREFER A COMPROMISE OF THEIR WELL
CLUSTERED SOLUTIONS INTO MON...ALBEIT WITH GULF LOW DEVELOPMENT
OPEN TO ADJUSTMENT AFTER COORDINATION WITH NHC. BY TUE/WED WE
LOSE THE UKMET AND THE 00 UTC CANADIAN OFFERS SUSPECT DEVELOPMENT
OF TWO SURFACE LOWS FROM THE NW MOVING MID-LEVEL LOW IN THE ERN
GULF OF MEX AND HAS A MORE ZONAL LOOK TO THE FLOW PATTERN ACROSS
CANADA THAN SEEN ON THE OTHER GUIDANCE. ACCORDINGLY...HPC PROGS
INSTEAD REMAIN PRIMARILY DERIVED FROM A BLEND OF THE COMPATABLE
00Z ECMWF/ECMWF ENSEMBLE MEAN TUE/WED.

[floridasun78]

000
FXUS62 KMFL 060833
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
433 AM EDT THU OCT 6 2011

THE 00Z GFS TRIES TO DEVELOP A WEAK SURFACE LOW ALONG THE FRONT
OVER THE BAHAMA ISLANDS SATURDAY NIGHT WHILE THE 00Z ECMWF TRY TO
DEVELOP A WEAK LOW OVER THE EASTERN GULF OF MEXICO DURING THE SAME
TIME. EITHER WAY...THE THERE WILL BE A CHANCE OF RAIN SHOWERS AND
EVENING A FEW THUNDERSTORMS OVER THE CWA SATURDAY INTO SATURDAY
NIGHT EXCEPT FOR LIKELY ACTIVITY OVER THE NORTHEAST PORTIONS OF
THE CWA. THE PWAT VALUES DURING THIS TIME IS ALSO BETWEEN 1.7 AND
2 INCHES ON SATURDAY AND SATURDAY NIGHT. SO THERE COULD BE SOME
LOCALLY HEAVY RAINFALL ACROSS THE CWA ESPECIALLY OVER THE EAST
COAST METRO AREAS DUE HIGH PWAT VALUES AND THE FRICTION OF THE
WIND SPEEDS.

FOR SUNDAY AND SUNDAY NIGHT...
THE HIGH OVER THE MID ATLANTIC STATES WILL START TO MOVE SLOWLY
EAST INTO THE ATLANTIC WATERS ALLOWING FOR THE MID TO UPPER LEVEL
LOW OVER THE EASTERN GULF WATERS TO MOVE NORTH TOWARDS THE WEST
CENTRAL FLORIDA COAST. AT THE SAME TIME...THE GFS TAKES THE WEAK
LOW IN THE BAHAMA ISLAND AND MOVES IT NORTH TO OFF THE EAST COAST
OF CENTRAL FLORIDA...WHILE THE ECMWF TAKES ITS LOW NORTHWARD TO
OFF THE WEST COAST OF CENTRAL FLORIDA. THIS IN TURN WILL PUSH THE
FRONTAL BOUNDARY NORTHWARD INTO CENTRAL FLORIDA ON SUNDAY...AND
ALLOW FOR THE PRESSURE GRADIENT TO RELAX OVER THE CWA ALONG WITH
LOWERING THE PWAT VALUES. SO THE LOCALLY HEAVY RAINFALL WILL BE
LESS..BUT THE COVERAGE WILL STILL BE IN THE HIGH IN CHANCE CAT FOR
SUNDAY OVER SOUTH FLORIDA.

FOR THE RAINFALL PENITENTIAL OVER SOUTH FLORIDA FOR THIS UPCOMING
WEEKEND...PLEASE SEE THE ESF HYDRO STATEMENT.


miami weather office making low non tropical what i see

[cycloneye]

Shouldn't the EPAC be already inactive this time around in a La Nina year?

Pretty good wet MJO pulse is the cause.

[ronjon]

Lates HPC Discussion. They are going with the Euro guidnace with development of the subtropical low off the western tip of Cuba Sunday morning and heading north in the eastern GOM.

THE 00Z GFS IS TOO QUICK WITH A SYSTEM ENTERING THE PLAINS EARLY
ON AND FORMS THE SUBTROPICAL CYCLONE OVER THE BAHAMA BANK...A
SOLUTION ONLY SUPPORT BY ONE-EIGHTH OF THE 00Z GLOBAL ENSEMBLE
GUIDANCE...MOVES IT TOWARDS THE NORTHEAST FLORIDA/GEORGIA COAST
THEN JUMPS CENTERS OFFSHORE CAPE HATTERAS BEFORE ACCELERATING THE
SYSTEM OFFSHORE CAPE COD...ON THE FAST SIDE OF THE OVERALL GLOBAL
ENSEMBLE SPREAD...SO IT WAS NOT USED DUE TO ITS KNOWN FAST BIAS.
THE 00Z UKMET/00Z ECMWF/00Z CANADIAN WERE IN GOOD AGREEMENT
OUTSIDE THE SOUTHEAST...SO USED THOSE PIECES OF GUIDANCE THROUGH
TUESDAY.

THE 00Z CANADIAN IN PARTICULAR ACCELERATES THE SUBTROPICAL CYCLONE
INTO THE GREAT LAKES BY THURSDAY MORNING /WELL AHEAD OF THE 12Z
GLOBAL ENSEMBLE GUIDANCE/ AND FORMS ANOTHER HURRICANE-LIKE VORTEX
IN THE WESTERN CARIBBEAN WHICH MOVES AT A FORWARD MOTION OF 30
KNOTS OFFSHORE THE SOUTHEAST COAST...WHICH LIMITED ITS UTILITY
LATE IN THE PERIOD. BECAUSE OF THE UNCERTAINTY PRESENT LATE IN
THE PERIOD...USED A 00Z ECMWF/12Z ECMWF ENSEMBLE MEAN COMPROMISE
FOR THE PRESSURES NEXT WEDNESDAY AND THURSDAY...GOING SLIGHTLY
FASTER THAN THE MIDDLE OF THE BROAD ENSEMBLE SPREAD WITH THE
FRONTAL WAVE ALONG THE EAST COAST LATE IN THE PERIOD AS THE GLOBAL
ENSEMBLE GUIDANCE HAS SHOWN SOME ACCELERATION TO THIS SYSTEM OVER
ITS PAST COUPLE DAYS OF RUNS. THIS KEEPS REASONABLE CONTINUITY
WITH ALL SYSTEMS ON THE MAP...THOUGH THE HYBRID/SUBTROPICAL
CYCLONE-TURNED-FRONTAL WAVE IS MOVED SOMEWHAT FASTER THAN THE
POINTS COORDINATED BETWEEN HPC AND NHC AT 17Z ON WEDNESDAY. WET
AND WINDY WEATHER REMAINS SLATED FOR FLORIDA...POSSIBLY UP THE
COAST OF MUCH OF THE EASTERN SEABOARD BY NEXT THURSDAY.

[Canelaw99]

000
FXUS62 KMFL 060833
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
433 AM EDT THU OCT 6 2011

FOR THE RAINFALL PENITENTIAL OVER SOUTH FLORIDA FOR THIS UPCOMING....

'penitential' huh? Lol Somebody might need another cup of coffee before proofreading

[KUEFC]

Doesnt even look subtropical to my very inexperianced eye on the latest model runs, even the O6Z GFS, i seem to remember AJC3 mentioning the possibility of this just staying as a weak closed low.

[jdray]

NWS JAX is going along with the HPC. The Euro seems to be the model to follow for now.
A low, a high, and another low. Interesting week ahead.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
416 AM EDT THU OCT 6 2011

.SHORT TERM...NORTHEAST FLOW CONTINUES TO STRENGTHEN WITH LARGE
HIGH PRESSURE SYSTEM CURRENTLY CENTERED OVER THE NEW ENGLAND
STATES. WINDS AT THE COAST WERE BREEZY WITH SUSTAINED WINDS
AROUND 15 MPH. A BROAD AREA OF SURFACE MOISTURE FLUX CONVERGENCE
HAS ESTABLISHED OVER THE NORTHEAST FLORIDA COASTAL SECTIONS...
WHICH IS THE FOCUS FOR ONGOING SHOWERS OVER FLAGLER...SOUTHERN
PUTNAM AND MARION COUNTIES.

MID/UPPER LEVEL LOW IS CURRENTLY ADVANCING ACROSS THE FLORIDA
PENINSULA AND THIS FEATURE IS ENHANCING AFOREMENTIONED
SHOWERS...WITH KJAX DOPPLER RADAR INDICATING RAINFALL TOTALS
UPWARDS OF AN INCH IN FLAGLER COUNTY. WE ANTICIPATE THESE SHOWERS WILL
PERSIST BUT WEAKEN SOMEWHAT WITH PASSAGE OF THIS LOW.

AS BEEN ADVERTISED FOR SEVERAL DAYS...A SIGNIFICANT COASTAL EVENT
IS SHAPING UP. STRONG HIGH PRESSURE IS FORECAST TO SLIDE SOUTHWARD
TOWARDS THE MID-ATLANTIC STATES THROUGH THE WEEKEND...WITH STRONG
NORTHEAST WINDS CONTINUING OVER THE COASTAL SECTIONS. DIFFICULT
TO DETERMINE WHERE TRAINING OF SHOWERS WILL OCCUR WITH THIS
EVENT...BUT WE CURRENTLY FEEL THE GREATEST COVERAGE OF SHOWERS
WILL OCCUR ACROSS COASTAL NORTHEAST FLORIDA WHERE I HAVE INCLUDED
LIKELY POPS BEGINNING FRIDAY.

FOR TODAY...HAVE INCLUDED SCATTERED POPS EAST OF U.S. HIGHWAY
301...WITH ISOLATED/NIL POPS FOR THE BALANCE OF THE FORECAST AREA.
BREEZY CONDITIONS WILL ESTABLISH OVER THE EASTERN HALF OF THE CWA
WHERE NORTHEAST WINDS WILL INCREASE TO 15 TO 20 MPH WITH GUSTS
NEAR 30 MPH NEAR THE COAST AND ALONG THE ST. JOHNS RIVER BASIN.
THIS IS JUST BELOW LAKE WIND ADVISORY CRITERIA. MILD CONDITIONS
ARE FORECAST TODAY WITH AFTERNOON HIGHS IN THE LOWER TO MID
80S...WARMEST ACROSS THE FAR INTERIOR.

RAIN CHANCES WILL SLOWLY INCREASE THROUGH THE SHORT-TERM AND AS
MENTIONED ABOVE...SHOWERS WILL BECOME NUMEROUS OVER THE COASTAL
SECTIONS BY THURSDAY NIGHT/FRIDAY.

WITH WINDS FORECAST TO FURTHER INCREASE...A LAKE WIND ADVISORY IS
ANTICIPATED FOR PORTIONS OF THE FORECAST AREA BEGINNING FRIDAY.

WILL HOLD OFF ISSUING COASTAL FLOOD WATCH WITH THIS PACKAGE AS
ANY FLOODING SHOULD HOLD OFF UNTIL LATER IN THE WEEKEND. WILL
CONTINUE TO ADVERTISE COASTAL CONCERNS IN THE HWO PRODUCT.
ADDITIONAL INFORMATION ON THIS EVENT IS AVAILABLE ON OUR
WEBSITE...INCLUDING A WEB BRIEFING AND GRAPHICAST.

.LONG TERM (SUN-WED)...SIGNIFICANT COASTAL EVENT WILL BE WELL
UNDERWAY BY SUNDAY...AND WE ANTICIPATE POUNDING SURF/HIGH RISK OF
RIP CURRENTS...BEACH EROSION AND POSSIBLY COASTAL FLOODING AROUND
HIGH TIDE CYCLES. WILL LIKELY NEED A HIGH SURF ADVISORY FOR
BREAKER HEIGHTS OF 7 FEET ON SUNDAY AS WELL AS A COASTAL FLOOD
WATCH/WARNING. INTERESTS SHOULD CONTINUE TO MONITOR FOR THE LATEST
FORECASTS AND PRODUCTS ON THIS EVOLVING EVENT.

CONCERNING THE AREA OF LOW PRESSURE THAT IS EXPECTED TO FORM IN
THE CARIBBEAN...LATEST MODEL RUNS DO NOT APPEAR ANY MORE CLEAR CUT
WITH REGARD TO THE DETAILS OF THIS FEATURE. WE CONTINUE TO PREFER
THE EUROPEAN SOLUTION WHICH INDICATES THE LOW WILL INITIALLY
ADVANCE NORTH-NORTHWEST OVER THE GULF OF MEXICO THEN EJECT
NORTHEAST BY MIDDLE PART OF NEXT WEEK. WE PREFER THIS SOLUTION AS
HEIGHT FIELDS WILL LIKELY BUILD ALONG THE EASTERN SEABOARD EARLY
NEXT WEEK...STEERING LOW FARTHER WEST.

[maxx9512]

Looks like they are leaning toward the ECMWF solution.

NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
252 AM EDT THU OCT 6 2011

LONG TERM (SATURDAY NIGHT-WEDNESDAY)... STRONG SURFACE HIGH
PRESSURE WILL HOLD ALONG THE MID ATLANTIC COAST SUNDAY WITH A
STATIONARY BOUNDARY OVER THE FLORIDA STRAITS. TIGHT PRESSURE
GRADIENT BETWEEN THE TWO SYSTEMS WILL CONTINUE OVER THE EASTERN
GULF OF MEXICO WITH SMALL CRAFT ADVISORY CONDITIONS A GOOD
POSSIBILITY. CONSIDERABLE UNCERTAINTY IN THE LONG RANGE FORECAST
AS THE GFS AND ECMWF GENERATE A TROPICAL/HYBRID SYSTEM ON THE
STATIONARY BOUNDARY LATE IN THE WEEKEND WITH SIGNIFICANTLY
DIFFERENT TRACK SOLUTIONS...THE GFS TRACKING OFF THE EAST COAST OF
THE FLORIDA PENINSULA AND THE ECMWF OVER THE EASTERN GULF OF
MEXICO MOVING NORTH TOWARD THE FLORIDA BIG BEND. CONSENSUS HAS
BEEN WITH THE ECMWF AS IT HAS BEEN CONSISTENT RUN TO RUN AND WILL
BE FOLLOWED AGAIN TONIGHT. DEEP TROPICAL MOISTURE WILL BEGIN TO
LIFT NORTH ACROSS THE FLORIDA PENINSULA SATURDAY NIGHT AND SUNDAY
WITH AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. INITIALLY
SUNDAY AND MONDAY...EASTERLY FLOW ACROSS THE PENINSULA WILL FAVOR
HEAVIER RAIN MOVING ONSHORE THE ATLANTIC COAST WITH LIGHTER
AMOUNTS OVER WEST CENTRAL AND SOUTHWEST FLORIDA...BUT STILL
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE FORECAST
AREA. BUT IF THE STORM TRACKS OVER THE EASTERN GULF ON MONDAY PER
THE ECMWF...WINDS WILL BECOME SOUTHERLY OVER THE FORECAST AREA
WITH THE THREAT OF LOCALLY HEAVY RAIN DEVELOPING OVER WEST CENTRAL
AND SOUTHWEST FLORIDA MONDAY NIGHT AND TUESDAY. DEPENDING ON THE
EVENTUAL STRENGTH OF THE STORM SYSTEM...SOME COASTAL FLOODING IS
ALSO POSSIBLE. THE SYSTEM IS EXPECTED TO LIFT NORTH OF THE REGION
TUESDAY NIGHT AND WEDNESDAY WITH DECREASING WINDS AND SEAS...AND
DIMINISHING RAIN CHANCES. AGAIN...UNCERTAINTY REMAINS HIGH
REGARDING TIMING AND TRACK OF THIS SYSTEM...AND EVENTUAL EVOLUTION
OF THIS SYSTEM WILL HAVE TO BE CLOSELY MONITORED THROUGH THE
WEEKEND. TEMPERATURES WILL RUN NEAR TO SLIGHTLY ABOVE CLIMATIC
NORMALS THROUGH THE PERIOD...ESPECIALLY WITH OVERNIGHT MINIMUM
TEMPERATURES. MEX POP/TEMP GUIDANCE WAS DISCOUNTED AS IT RELIES ON
THE GFS SOLUTION.

[cycloneye]

Will this suspisious area in the Southern Bahamas be the starting point of the much anticipated sub or tropical system that the models have been advertising for many runs?

[KUEFC]

Isnt it just part of the front? seems to be moving east?

Also is it just me, or has the dry air dropped more south than people thought? looking at water vapor loops its dropped right down to the tip of Cuba, and a portion of the bahamas?

[Frank2]

My guess is that anything that does form, will form to our east - there's absolutely nothing in the NW Caribbean or GOM at this time, so highly unlikely that something would form so quickly in either area for this weekend - that'd be very very unusual, but more likely to our east, on the end of that old frontal trough:

http://www.goes.noaa.gov/browsh.html

[KUEFC]

Or have the models just got it wrong? I mean at one point the GFS was hinting towards a tropical storm, but last few runs is starting to trend weaker? Do models get things wrong? I dont know as i said am new to all this

[Steve H.]

YOu might be onto something there Luis. Caught my eye as well - on the tail of the front. Waiting for mid level low to drop down with the back door front. Once the ridge settles in to the north it can start to develop. Frank has a point here, it could develop farther east than most models are showing. First a sub-tropical or colder core low, then perhaps a more tropical system if conditions allow, as it moves WNW.

[SFLcane]

12z NAM seems to develope this area and brings it westward towards SFL and Keys.

[boca]

The whole area continues to move east I saw that area too but its moving away.

[LarryWx]

My guess is that anything that does form, will form to our east - there's absolutely nothing in the NW Caribbean or GOM at this time, so highly unlikely that something would form so quickly in either area for this weekend - that'd be very very unusual, but more likely to our east, on the end of that old frontal trough:

http://www.goes.noaa.gov/browsh.html

Yep, although not necessarily from that parcel of moisture now showing up per se, the area near the SE Bahamas appears to be the area to watch over the next couple of days as the energy there is projected to generally move WNW and then NW to quite possibly form a cyclone that then quite possibly transitions to tropical pretty quickly and subsequently threatens the SE US per the GFS. This is just a possibiity but a realistic one given the current/near future setup of deep NE US riding.

[KUEFC]

The wholw area continues to move east I saw that area too but its moving away.

Yep, the whole area seems to be caught up in whatever is dragging Phillipe away IMO

[KUEFC]

My guess is that anything that does form, will form to our east - there's absolutely nothing in the NW Caribbean or GOM at this time, so highly unlikely that something would form so quickly in either area for this weekend - that'd be very very unusual, but more likely to our east, on the end of that old frontal trough:

http://www.goes.noaa.gov/browsh.html

Yep, although not necessarily from that parcel of moisture now showing up per se, the area near the SE Bahamas appears to be the area to watch over the next couple of days as the energy there is projected to generally move WNW and then NW to quite possibly form a cyclone that then quite possibly transitions to tropical pretty quickly and subsequently threatens the SE US per the GFS. This is just a possibiity but a realistic one given the current/near future setup of deep NE US riding.

But at this very moment in time it all seems to be moving ene pretty rapidly, going off the water vapor loop, or thats what i am seeing anyway,

[boca]

I like to know where to look for this development because the area to the east is moving quickly ene away.If it was lingering then i think the models would be on to something,but I see nothing.

[LarryWx]

I like to know where to look for this development because the area to the east is moving quickly ene away.If it was lingering then i think the models would be on to something,but I see nothing.

Boca,
If you look at the last few GFS runs, you'll see that the cyclone forms from something that really won't even be visible until late Fri. night or early Sat. Even the last two Euro runs show nothing visible until tomorrow morning. In essence, the seed is not yet visible and won't be for another 36-48 hours if you believe the GFS.
Patience, folks. I know it has been boring in these parts, but some more waiting is needed. I'm pretty confident that come Sat. night the satellite pics will look more and more interesting starting by Friday night and getting quite interesting by Sat. night.